linux/Documentation/pinctrl.txt

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drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
PINCTRL (PIN CONTROL) subsystem
This document outlines the pin control subsystem in Linux
This subsystem deals with:
- Enumerating and naming controllable pins
- Multiplexing of pins, pads, fingers (etc) see below for details
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:14:33 +00:00
- Configuration of pins, pads, fingers (etc), such as software-controlled
biasing and driving mode specific pins, such as pull-up/down, open drain,
load capacitance etc.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
Top-level interface
===================
Definition of PIN CONTROLLER:
- A pin controller is a piece of hardware, usually a set of registers, that
can control PINs. It may be able to multiplex, bias, set load capacitance,
set drive strength etc for individual pins or groups of pins.
Definition of PIN:
- PINS are equal to pads, fingers, balls or whatever packaging input or
output line you want to control and these are denoted by unsigned integers
in the range 0..maxpin. This numberspace is local to each PIN CONTROLLER, so
there may be several such number spaces in a system. This pin space may
be sparse - i.e. there may be gaps in the space with numbers where no
pin exists.
When a PIN CONTROLLER is instantiated, it will register a descriptor to the
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
pin control framework, and this descriptor contains an array of pin descriptors
describing the pins handled by this specific pin controller.
Here is an example of a PGA (Pin Grid Array) chip seen from underneath:
A B C D E F G H
8 o o o o o o o o
7 o o o o o o o o
6 o o o o o o o o
5 o o o o o o o o
4 o o o o o o o o
3 o o o o o o o o
2 o o o o o o o o
1 o o o o o o o o
To register a pin controller and name all the pins on this package we can do
this in our driver:
#include <linux/pinctrl/pinctrl.h>
const struct pinctrl_pin_desc foo_pins[] = {
PINCTRL_PIN(0, "A8"),
PINCTRL_PIN(1, "B8"),
PINCTRL_PIN(2, "C8"),
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
...
PINCTRL_PIN(61, "F1"),
PINCTRL_PIN(62, "G1"),
PINCTRL_PIN(63, "H1"),
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
};
static struct pinctrl_desc foo_desc = {
.name = "foo",
.pins = foo_pins,
.npins = ARRAY_SIZE(foo_pins),
.maxpin = 63,
.owner = THIS_MODULE,
};
int __init foo_probe(void)
{
struct pinctrl_dev *pctl;
pctl = pinctrl_register(&foo_desc, <PARENT>, NULL);
if (IS_ERR(pctl))
pr_err("could not register foo pin driver\n");
}
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:14:33 +00:00
To enable the pinctrl subsystem and the subgroups for PINMUX and PINCONF and
selected drivers, you need to select them from your machine's Kconfig entry,
since these are so tightly integrated with the machines they are used on.
See for example arch/arm/mach-u300/Kconfig for an example.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
Pins usually have fancier names than this. You can find these in the dataheet
for your chip. Notice that the core pinctrl.h file provides a fancy macro
called PINCTRL_PIN() to create the struct entries. As you can see I enumerated
the pins from 0 in the upper left corner to 63 in the lower right corner.
This enumeration was arbitrarily chosen, in practice you need to think
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
through your numbering system so that it matches the layout of registers
and such things in your driver, or the code may become complicated. You must
also consider matching of offsets to the GPIO ranges that may be handled by
the pin controller.
For a padring with 467 pads, as opposed to actual pins, I used an enumeration
like this, walking around the edge of the chip, which seems to be industry
standard too (all these pads had names, too):
0 ..... 104
466 105
. .
. .
358 224
357 .... 225
Pin groups
==========
Many controllers need to deal with groups of pins, so the pin controller
subsystem has a mechanism for enumerating groups of pins and retrieving the
actual enumerated pins that are part of a certain group.
For example, say that we have a group of pins dealing with an SPI interface
on { 0, 8, 16, 24 }, and a group of pins dealing with an I2C interface on pins
on { 24, 25 }.
These two groups are presented to the pin control subsystem by implementing
some generic pinctrl_ops like this:
#include <linux/pinctrl/pinctrl.h>
struct foo_group {
const char *name;
const unsigned int *pins;
const unsigned num_pins;
};
static const unsigned int spi0_pins[] = { 0, 8, 16, 24 };
static const unsigned int i2c0_pins[] = { 24, 25 };
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
static const struct foo_group foo_groups[] = {
{
.name = "spi0_grp",
.pins = spi0_pins,
.num_pins = ARRAY_SIZE(spi0_pins),
},
{
.name = "i2c0_grp",
.pins = i2c0_pins,
.num_pins = ARRAY_SIZE(i2c0_pins),
},
};
static int foo_get_groups_count(struct pinctrl_dev *pctldev)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
{
return ARRAY_SIZE(foo_groups);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
}
static const char *foo_get_group_name(struct pinctrl_dev *pctldev,
unsigned selector)
{
return foo_groups[selector].name;
}
static int foo_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
unsigned ** const pins,
unsigned * const num_pins)
{
*pins = (unsigned *) foo_groups[selector].pins;
*num_pins = foo_groups[selector].num_pins;
return 0;
}
static struct pinctrl_ops foo_pctrl_ops = {
.get_groups_count = foo_get_groups_count,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.get_group_name = foo_get_group_name,
.get_group_pins = foo_get_group_pins,
};
static struct pinctrl_desc foo_desc = {
...
.pctlops = &foo_pctrl_ops,
};
The pin control subsystem will call the .get_groups_count() function to
determine total number of legal selectors, then it will call the other functions
to retrieve the name and pins of the group. Maintaining the data structure of
the groups is up to the driver, this is just a simple example - in practice you
may need more entries in your group structure, for example specific register
ranges associated with each group and so on.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:14:33 +00:00
Pin configuration
=================
Pins can sometimes be software-configured in an various ways, mostly related
to their electronic properties when used as inputs or outputs. For example you
may be able to make an output pin high impedance, or "tristate" meaning it is
effectively disconnected. You may be able to connect an input pin to VDD or GND
using a certain resistor value - pull up and pull down - so that the pin has a
stable value when nothing is driving the rail it is connected to, or when it's
unconnected.
Pin configuration can be programmed either using the explicit APIs described
immediately below, or by adding configuration entries into the mapping table;
see section "Board/machine configuration" below.
For example, a platform may do the following to pull up a pin to VDD:
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:14:33 +00:00
#include <linux/pinctrl/consumer.h>
ret = pin_config_set("foo-dev", "FOO_GPIO_PIN", PLATFORM_X_PULL_UP);
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:14:33 +00:00
The format and meaning of the configuration parameter, PLATFORM_X_PULL_UP
above, is entirely defined by the pin controller driver.
The pin configuration driver implements callbacks for changing pin
configuration in the pin controller ops like this:
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:14:33 +00:00
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinconf.h>
#include "platform_x_pindefs.h"
static int foo_pin_config_get(struct pinctrl_dev *pctldev,
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:14:33 +00:00
unsigned offset,
unsigned long *config)
{
struct my_conftype conf;
... Find setting for pin @ offset ...
*config = (unsigned long) conf;
}
static int foo_pin_config_set(struct pinctrl_dev *pctldev,
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:14:33 +00:00
unsigned offset,
unsigned long config)
{
struct my_conftype *conf = (struct my_conftype *) config;
switch (conf) {
case PLATFORM_X_PULL_UP:
...
}
}
}
static int foo_pin_config_group_get (struct pinctrl_dev *pctldev,
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:14:33 +00:00
unsigned selector,
unsigned long *config)
{
...
}
static int foo_pin_config_group_set (struct pinctrl_dev *pctldev,
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:14:33 +00:00
unsigned selector,
unsigned long config)
{
...
}
static struct pinconf_ops foo_pconf_ops = {
.pin_config_get = foo_pin_config_get,
.pin_config_set = foo_pin_config_set,
.pin_config_group_get = foo_pin_config_group_get,
.pin_config_group_set = foo_pin_config_group_set,
};
/* Pin config operations are handled by some pin controller */
static struct pinctrl_desc foo_desc = {
...
.confops = &foo_pconf_ops,
};
Since some controllers have special logic for handling entire groups of pins
they can exploit the special whole-group pin control function. The
pin_config_group_set() callback is allowed to return the error code -EAGAIN,
for groups it does not want to handle, or if it just wants to do some
group-level handling and then fall through to iterate over all pins, in which
case each individual pin will be treated by separate pin_config_set() calls as
well.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
Interaction with the GPIO subsystem
===================================
The GPIO drivers may want to perform operations of various types on the same
physical pins that are also registered as pin controller pins.
First and foremost, the two subsystems can be used as completely orthogonal,
see the section named "pin control requests from drivers" and
"drivers needing both pin control and GPIOs" below for details. But in some
situations a cross-subsystem mapping between pins and GPIOs is needed.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
Since the pin controller subsystem have its pinspace local to the pin
controller we need a mapping so that the pin control subsystem can figure out
which pin controller handles control of a certain GPIO pin. Since a single
pin controller may be muxing several GPIO ranges (typically SoCs that have
one set of pins but internally several GPIO silicon blocks, each modeled as
a struct gpio_chip) any number of GPIO ranges can be added to a pin controller
instance like this:
struct gpio_chip chip_a;
struct gpio_chip chip_b;
static struct pinctrl_gpio_range gpio_range_a = {
.name = "chip a",
.id = 0,
.base = 32,
.pin_base = 32,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.npins = 16,
.gc = &chip_a;
};
static struct pinctrl_gpio_range gpio_range_b = {
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.name = "chip b",
.id = 0,
.base = 48,
.pin_base = 64,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.npins = 8,
.gc = &chip_b;
};
{
struct pinctrl_dev *pctl;
...
pinctrl_add_gpio_range(pctl, &gpio_range_a);
pinctrl_add_gpio_range(pctl, &gpio_range_b);
}
So this complex system has one pin controller handling two different
GPIO chips. "chip a" has 16 pins and "chip b" has 8 pins. The "chip a" and
"chip b" have different .pin_base, which means a start pin number of the
GPIO range.
The GPIO range of "chip a" starts from the GPIO base of 32 and actual
pin range also starts from 32. However "chip b" has different starting
offset for the GPIO range and pin range. The GPIO range of "chip b" starts
from GPIO number 48, while the pin range of "chip b" starts from 64.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
We can convert a gpio number to actual pin number using this "pin_base".
They are mapped in the global GPIO pin space at:
chip a:
- GPIO range : [32 .. 47]
- pin range : [32 .. 47]
chip b:
- GPIO range : [48 .. 55]
- pin range : [64 .. 71]
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
When GPIO-specific functions in the pin control subsystem are called, these
ranges will be used to look up the appropriate pin controller by inspecting
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
and matching the pin to the pin ranges across all controllers. When a
pin controller handling the matching range is found, GPIO-specific functions
will be called on that specific pin controller.
For all functionalities dealing with pin biasing, pin muxing etc, the pin
controller subsystem will subtract the range's .base offset from the passed
in gpio number, and add the ranges's .pin_base offset to retrive a pin number.
After that, the subsystem passes it on to the pin control driver, so the driver
will get an pin number into its handled number range. Further it is also passed
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
the range ID value, so that the pin controller knows which range it should
deal with.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
PINMUX interfaces
=================
These calls use the pinmux_* naming prefix. No other calls should use that
prefix.
What is pinmuxing?
==================
PINMUX, also known as padmux, ballmux, alternate functions or mission modes
is a way for chip vendors producing some kind of electrical packages to use
a certain physical pin (ball, pad, finger, etc) for multiple mutually exclusive
functions, depending on the application. By "application" in this context
we usually mean a way of soldering or wiring the package into an electronic
system, even though the framework makes it possible to also change the function
at runtime.
Here is an example of a PGA (Pin Grid Array) chip seen from underneath:
A B C D E F G H
+---+
8 | o | o o o o o o o
| |
7 | o | o o o o o o o
| |
6 | o | o o o o o o o
+---+---+
5 | o | o | o o o o o o
+---+---+ +---+
4 o o o o o o | o | o
| |
3 o o o o o o | o | o
| |
2 o o o o o o | o | o
+-------+-------+-------+---+---+
1 | o o | o o | o o | o | o |
+-------+-------+-------+---+---+
This is not tetris. The game to think of is chess. Not all PGA/BGA packages
are chessboard-like, big ones have "holes" in some arrangement according to
different design patterns, but we're using this as a simple example. Of the
pins you see some will be taken by things like a few VCC and GND to feed power
to the chip, and quite a few will be taken by large ports like an external
memory interface. The remaining pins will often be subject to pin multiplexing.
The example 8x8 PGA package above will have pin numbers 0 thru 63 assigned to
its physical pins. It will name the pins { A1, A2, A3 ... H6, H7, H8 } using
pinctrl_register_pins() and a suitable data set as shown earlier.
In this 8x8 BGA package the pins { A8, A7, A6, A5 } can be used as an SPI port
(these are four pins: CLK, RXD, TXD, FRM). In that case, pin B5 can be used as
some general-purpose GPIO pin. However, in another setting, pins { A5, B5 } can
be used as an I2C port (these are just two pins: SCL, SDA). Needless to say,
we cannot use the SPI port and I2C port at the same time. However in the inside
of the package the silicon performing the SPI logic can alternatively be routed
out on pins { G4, G3, G2, G1 }.
On the botton row at { A1, B1, C1, D1, E1, F1, G1, H1 } we have something
special - it's an external MMC bus that can be 2, 4 or 8 bits wide, and it will
consume 2, 4 or 8 pins respectively, so either { A1, B1 } are taken or
{ A1, B1, C1, D1 } or all of them. If we use all 8 bits, we cannot use the SPI
port on pins { G4, G3, G2, G1 } of course.
This way the silicon blocks present inside the chip can be multiplexed "muxed"
out on different pin ranges. Often contemporary SoC (systems on chip) will
contain several I2C, SPI, SDIO/MMC, etc silicon blocks that can be routed to
different pins by pinmux settings.
Since general-purpose I/O pins (GPIO) are typically always in shortage, it is
common to be able to use almost any pin as a GPIO pin if it is not currently
in use by some other I/O port.
Pinmux conventions
==================
The purpose of the pinmux functionality in the pin controller subsystem is to
abstract and provide pinmux settings to the devices you choose to instantiate
in your machine configuration. It is inspired by the clk, GPIO and regulator
subsystems, so devices will request their mux setting, but it's also possible
to request a single pin for e.g. GPIO.
Definitions:
- FUNCTIONS can be switched in and out by a driver residing with the pin
control subsystem in the drivers/pinctrl/* directory of the kernel. The
pin control driver knows the possible functions. In the example above you can
identify three pinmux functions, one for spi, one for i2c and one for mmc.
- FUNCTIONS are assumed to be enumerable from zero in a one-dimensional array.
In this case the array could be something like: { spi0, i2c0, mmc0 }
for the three available functions.
- FUNCTIONS have PIN GROUPS as defined on the generic level - so a certain
function is *always* associated with a certain set of pin groups, could
be just a single one, but could also be many. In the example above the
function i2c is associated with the pins { A5, B5 }, enumerated as
{ 24, 25 } in the controller pin space.
The Function spi is associated with pin groups { A8, A7, A6, A5 }
and { G4, G3, G2, G1 }, which are enumerated as { 0, 8, 16, 24 } and
{ 38, 46, 54, 62 } respectively.
Group names must be unique per pin controller, no two groups on the same
controller may have the same name.
- The combination of a FUNCTION and a PIN GROUP determine a certain function
for a certain set of pins. The knowledge of the functions and pin groups
and their machine-specific particulars are kept inside the pinmux driver,
from the outside only the enumerators are known, and the driver core can:
- Request the name of a function with a certain selector (>= 0)
- A list of groups associated with a certain function
- Request that a certain group in that list to be activated for a certain
function
As already described above, pin groups are in turn self-descriptive, so
the core will retrieve the actual pin range in a certain group from the
driver.
- FUNCTIONS and GROUPS on a certain PIN CONTROLLER are MAPPED to a certain
device by the board file, device tree or similar machine setup configuration
mechanism, similar to how regulators are connected to devices, usually by
name. Defining a pin controller, function and group thus uniquely identify
the set of pins to be used by a certain device. (If only one possible group
of pins is available for the function, no group name need to be supplied -
the core will simply select the first and only group available.)
In the example case we can define that this particular machine shall
use device spi0 with pinmux function fspi0 group gspi0 and i2c0 on function
fi2c0 group gi2c0, on the primary pin controller, we get mappings
like these:
{
{"map-spi0", spi0, pinctrl0, fspi0, gspi0},
{"map-i2c0", i2c0, pinctrl0, fi2c0, gi2c0}
}
Every map must be assigned a state name, pin controller, device and
function. The group is not compulsory - if it is omitted the first group
presented by the driver as applicable for the function will be selected,
which is useful for simple cases.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
It is possible to map several groups to the same combination of device,
pin controller and function. This is for cases where a certain function on
a certain pin controller may use different sets of pins in different
configurations.
- PINS for a certain FUNCTION using a certain PIN GROUP on a certain
PIN CONTROLLER are provided on a first-come first-serve basis, so if some
other device mux setting or GPIO pin request has already taken your physical
pin, you will be denied the use of it. To get (activate) a new setting, the
old one has to be put (deactivated) first.
Sometimes the documentation and hardware registers will be oriented around
pads (or "fingers") rather than pins - these are the soldering surfaces on the
silicon inside the package, and may or may not match the actual number of
pins/balls underneath the capsule. Pick some enumeration that makes sense to
you. Define enumerators only for the pins you can control if that makes sense.
Assumptions:
We assume that the number of possible function maps to pin groups is limited by
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
the hardware. I.e. we assume that there is no system where any function can be
mapped to any pin, like in a phone exchange. So the available pins groups for
a certain function will be limited to a few choices (say up to eight or so),
not hundreds or any amount of choices. This is the characteristic we have found
by inspecting available pinmux hardware, and a necessary assumption since we
expect pinmux drivers to present *all* possible function vs pin group mappings
to the subsystem.
Pinmux drivers
==============
The pinmux core takes care of preventing conflicts on pins and calling
the pin controller driver to execute different settings.
It is the responsibility of the pinmux driver to impose further restrictions
(say for example infer electronic limitations due to load etc) to determine
whether or not the requested function can actually be allowed, and in case it
is possible to perform the requested mux setting, poke the hardware so that
this happens.
Pinmux drivers are required to supply a few callback functions, some are
optional. Usually the enable() and disable() functions are implemented,
writing values into some certain registers to activate a certain mux setting
for a certain pin.
A simple driver for the above example will work by setting bits 0, 1, 2, 3 or 4
into some register named MUX to select a certain function with a certain
group of pins would work something like this:
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
struct foo_group {
const char *name;
const unsigned int *pins;
const unsigned num_pins;
};
static const unsigned spi0_0_pins[] = { 0, 8, 16, 24 };
static const unsigned spi0_1_pins[] = { 38, 46, 54, 62 };
static const unsigned i2c0_pins[] = { 24, 25 };
static const unsigned mmc0_1_pins[] = { 56, 57 };
static const unsigned mmc0_2_pins[] = { 58, 59 };
static const unsigned mmc0_3_pins[] = { 60, 61, 62, 63 };
static const struct foo_group foo_groups[] = {
{
.name = "spi0_0_grp",
.pins = spi0_0_pins,
.num_pins = ARRAY_SIZE(spi0_0_pins),
},
{
.name = "spi0_1_grp",
.pins = spi0_1_pins,
.num_pins = ARRAY_SIZE(spi0_1_pins),
},
{
.name = "i2c0_grp",
.pins = i2c0_pins,
.num_pins = ARRAY_SIZE(i2c0_pins),
},
{
.name = "mmc0_1_grp",
.pins = mmc0_1_pins,
.num_pins = ARRAY_SIZE(mmc0_1_pins),
},
{
.name = "mmc0_2_grp",
.pins = mmc0_2_pins,
.num_pins = ARRAY_SIZE(mmc0_2_pins),
},
{
.name = "mmc0_3_grp",
.pins = mmc0_3_pins,
.num_pins = ARRAY_SIZE(mmc0_3_pins),
},
};
static int foo_get_groups_count(struct pinctrl_dev *pctldev)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
{
return ARRAY_SIZE(foo_groups);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
}
static const char *foo_get_group_name(struct pinctrl_dev *pctldev,
unsigned selector)
{
return foo_groups[selector].name;
}
static int foo_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
unsigned ** const pins,
unsigned * const num_pins)
{
*pins = (unsigned *) foo_groups[selector].pins;
*num_pins = foo_groups[selector].num_pins;
return 0;
}
static struct pinctrl_ops foo_pctrl_ops = {
.get_groups_count = foo_get_groups_count,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.get_group_name = foo_get_group_name,
.get_group_pins = foo_get_group_pins,
};
struct foo_pmx_func {
const char *name;
const char * const *groups;
const unsigned num_groups;
};
static const char * const spi0_groups[] = { "spi0_0_grp", "spi0_1_grp" };
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
static const char * const i2c0_groups[] = { "i2c0_grp" };
static const char * const mmc0_groups[] = { "mmc0_1_grp", "mmc0_2_grp",
"mmc0_3_grp" };
static const struct foo_pmx_func foo_functions[] = {
{
.name = "spi0",
.groups = spi0_groups,
.num_groups = ARRAY_SIZE(spi0_groups),
},
{
.name = "i2c0",
.groups = i2c0_groups,
.num_groups = ARRAY_SIZE(i2c0_groups),
},
{
.name = "mmc0",
.groups = mmc0_groups,
.num_groups = ARRAY_SIZE(mmc0_groups),
},
};
int foo_get_functions_count(struct pinctrl_dev *pctldev)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
{
return ARRAY_SIZE(foo_functions);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
}
const char *foo_get_fname(struct pinctrl_dev *pctldev, unsigned selector)
{
return foo_functions[selector].name;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
}
static int foo_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
const char * const **groups,
unsigned * const num_groups)
{
*groups = foo_functions[selector].groups;
*num_groups = foo_functions[selector].num_groups;
return 0;
}
int foo_enable(struct pinctrl_dev *pctldev, unsigned selector,
unsigned group)
{
u8 regbit = (1 << selector + group);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
writeb((readb(MUX)|regbit), MUX)
return 0;
}
void foo_disable(struct pinctrl_dev *pctldev, unsigned selector,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
unsigned group)
{
u8 regbit = (1 << selector + group);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
writeb((readb(MUX) & ~(regbit)), MUX)
return 0;
}
struct pinmux_ops foo_pmxops = {
.get_functions_count = foo_get_functions_count,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.get_function_name = foo_get_fname,
.get_function_groups = foo_get_groups,
.enable = foo_enable,
.disable = foo_disable,
};
/* Pinmux operations are handled by some pin controller */
static struct pinctrl_desc foo_desc = {
...
.pctlops = &foo_pctrl_ops,
.pmxops = &foo_pmxops,
};
In the example activating muxing 0 and 1 at the same time setting bits
0 and 1, uses one pin in common so they would collide.
The beauty of the pinmux subsystem is that since it keeps track of all
pins and who is using them, it will already have denied an impossible
request like that, so the driver does not need to worry about such
things - when it gets a selector passed in, the pinmux subsystem makes
sure no other device or GPIO assignment is already using the selected
pins. Thus bits 0 and 1 in the control register will never be set at the
same time.
All the above functions are mandatory to implement for a pinmux driver.
Pin control interaction with the GPIO subsystem
===============================================
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
The public pinmux API contains two functions named pinctrl_request_gpio()
and pinctrl_free_gpio(). These two functions shall *ONLY* be called from
gpiolib-based drivers as part of their gpio_request() and
gpio_free() semantics. Likewise the pinctrl_gpio_direction_[input|output]
shall only be called from within respective gpio_direction_[input|output]
gpiolib implementation.
NOTE that platforms and individual drivers shall *NOT* request GPIO pins to be
controlled e.g. muxed in. Instead, implement a proper gpiolib driver and have
that driver request proper muxing and other control for its pins.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
The function list could become long, especially if you can convert every
individual pin into a GPIO pin independent of any other pins, and then try
the approach to define every pin as a function.
In this case, the function array would become 64 entries for each GPIO
setting and then the device functions.
For this reason there are two functions a pin control driver can implement
to enable only GPIO on an individual pin: .gpio_request_enable() and
.gpio_disable_free().
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
This function will pass in the affected GPIO range identified by the pin
controller core, so you know which GPIO pins are being affected by the request
operation.
If your driver needs to have an indication from the framework of whether the
GPIO pin shall be used for input or output you can implement the
.gpio_set_direction() function. As described this shall be called from the
gpiolib driver and the affected GPIO range, pin offset and desired direction
will be passed along to this function.
Alternatively to using these special functions, it is fully allowed to use
named functions for each GPIO pin, the pinctrl_request_gpio() will attempt to
obtain the function "gpioN" where "N" is the global GPIO pin number if no
special GPIO-handler is registered.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
Board/machine configuration
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
==================================
Boards and machines define how a certain complete running system is put
together, including how GPIOs and devices are muxed, how regulators are
constrained and how the clock tree looks. Of course pinmux settings are also
part of this.
A pin controller configuration for a machine looks pretty much like a simple
regulator configuration, so for the example array above we want to enable i2c
and spi on the second function mapping:
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
#include <linux/pinctrl/machine.h>
static const struct pinctrl_map mapping[] __initconst = {
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
{
.dev_name = "foo-spi.0",
.name = PINCTRL_STATE_DEFAULT,
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
.data.mux.function = "spi0",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
},
{
.dev_name = "foo-i2c.0",
.name = PINCTRL_STATE_DEFAULT,
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
.data.mux.function = "i2c0",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
},
{
.dev_name = "foo-mmc.0",
.name = PINCTRL_STATE_DEFAULT,
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
.data.mux.function = "mmc0",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
},
};
The dev_name here matches to the unique device name that can be used to look
up the device struct (just like with clockdev or regulators). The function name
must match a function provided by the pinmux driver handling this pin range.
As you can see we may have several pin controllers on the system and thus
we need to specify which one of them that contain the functions we wish
to map.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
You register this pinmux mapping to the pinmux subsystem by simply:
ret = pinctrl_register_mappings(mapping, ARRAY_SIZE(mapping));
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
Since the above construct is pretty common there is a helper macro to make
it even more compact which assumes you want to use pinctrl-foo and position
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
0 for mapping, for example:
static struct pinctrl_map __initdata mapping[] = {
PIN_MAP_MUX_GROUP("foo-i2c.o", PINCTRL_STATE_DEFAULT, "pinctrl-foo", NULL, "i2c0"),
};
The mapping table may also contain pin configuration entries. It's common for
each pin/group to have a number of configuration entries that affect it, so
the table entries for configuration reference an array of config parameters
and values. An example using the convenience macros is shown below:
static unsigned long i2c_grp_configs[] = {
FOO_PIN_DRIVEN,
FOO_PIN_PULLUP,
};
static unsigned long i2c_pin_configs[] = {
FOO_OPEN_COLLECTOR,
FOO_SLEW_RATE_SLOW,
};
static struct pinctrl_map __initdata mapping[] = {
PIN_MAP_MUX_GROUP("foo-i2c.0", PINCTRL_STATE_DEFAULT, "pinctrl-foo", "i2c0", "i2c0"),
PIN_MAP_CONFIGS_GROUP("foo-i2c.0", PINCTRL_STATE_DEFAULT, "pinctrl-foo", "i2c0", i2c_grp_configs),
PIN_MAP_CONFIGS_PIN("foo-i2c.0", PINCTRL_STATE_DEFAULT, "pinctrl-foo", "i2c0scl", i2c_pin_configs),
PIN_MAP_CONFIGS_PIN("foo-i2c.0", PINCTRL_STATE_DEFAULT, "pinctrl-foo", "i2c0sda", i2c_pin_configs),
};
Finally, some devices expect the mapping table to contain certain specific
named states. When running on hardware that doesn't need any pin controller
configuration, the mapping table must still contain those named states, in
order to explicitly indicate that the states were provided and intended to
be empty. Table entry macro PIN_MAP_DUMMY_STATE serves the purpose of defining
a named state without causing any pin controller to be programmed:
static struct pinctrl_map __initdata mapping[] = {
PIN_MAP_DUMMY_STATE("foo-i2c.0", PINCTRL_STATE_DEFAULT),
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
};
Complex mappings
================
As it is possible to map a function to different groups of pins an optional
.group can be specified like this:
...
{
.dev_name = "foo-spi.0",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.name = "spi0-pos-A",
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.function = "spi0",
.group = "spi0_0_grp",
},
{
.dev_name = "foo-spi.0",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.name = "spi0-pos-B",
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.function = "spi0",
.group = "spi0_1_grp",
},
...
This example mapping is used to switch between two positions for spi0 at
runtime, as described further below under the heading "Runtime pinmuxing".
Further it is possible for one named state to affect the muxing of several
groups of pins, say for example in the mmc0 example above, where you can
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
additively expand the mmc0 bus from 2 to 4 to 8 pins. If we want to use all
three groups for a total of 2+2+4 = 8 pins (for an 8-bit MMC bus as is the
case), we define a mapping like this:
...
{
.dev_name = "foo-mmc.0",
.name = "2bit"
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.function = "mmc0",
.group = "mmc0_1_grp",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
},
{
.dev_name = "foo-mmc.0",
.name = "4bit"
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.function = "mmc0",
.group = "mmc0_1_grp",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
},
{
.dev_name = "foo-mmc.0",
.name = "4bit"
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.function = "mmc0",
.group = "mmc0_2_grp",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
},
{
.dev_name = "foo-mmc.0",
.name = "8bit"
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
.function = "mmc0",
.group = "mmc0_1_grp",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
},
{
.dev_name = "foo-mmc.0",
.name = "8bit"
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.function = "mmc0",
.group = "mmc0_2_grp",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
},
{
.dev_name = "foo-mmc.0",
.name = "8bit"
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.function = "mmc0",
.group = "mmc0_3_grp",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
},
...
The result of grabbing this mapping from the device with something like
this (see next paragraph):
p = devm_pinctrl_get(dev);
s = pinctrl_lookup_state(p, "8bit");
ret = pinctrl_select_state(p, s);
or more simply:
p = devm_pinctrl_get_select(dev, "8bit");
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
Will be that you activate all the three bottom records in the mapping at
once. Since they share the same name, pin controller device, function and
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
device, and since we allow multiple groups to match to a single device, they
all get selected, and they all get enabled and disable simultaneously by the
pinmux core.
Pin control requests from drivers
=================================
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
Generally it is discouraged to let individual drivers get and enable pin
control. So if possible, handle the pin control in platform code or some other
place where you have access to all the affected struct device * pointers. In
some cases where a driver needs to e.g. switch between different mux mappings
at runtime this is not possible.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
A typical case is if a driver needs to switch bias of pins from normal
operation and going to sleep, moving from the PINCTRL_STATE_DEFAULT to
PINCTRL_STATE_SLEEP at runtime, re-biasing or even re-muxing pins to save
current in sleep mode.
A driver may request a certain control state to be activated, usually just the
default state like this:
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
#include <linux/pinctrl/consumer.h>
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
struct foo_state {
struct pinctrl *p;
struct pinctrl_state *s;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
...
};
foo_probe()
{
/* Allocate a state holder named "foo" etc */
struct foo_state *foo = ...;
foo->p = devm_pinctrl_get(&device);
if (IS_ERR(foo->p)) {
/* FIXME: clean up "foo" here */
return PTR_ERR(foo->p);
}
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
foo->s = pinctrl_lookup_state(foo->p, PINCTRL_STATE_DEFAULT);
if (IS_ERR(foo->s)) {
/* FIXME: clean up "foo" here */
return PTR_ERR(s);
}
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
ret = pinctrl_select_state(foo->s);
if (ret < 0) {
/* FIXME: clean up "foo" here */
return ret;
}
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
}
This get/lookup/select/put sequence can just as well be handled by bus drivers
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
if you don't want each and every driver to handle it and you know the
arrangement on your bus.
The semantics of the pinctrl APIs are:
- pinctrl_get() is called in process context to obtain a handle to all pinctrl
information for a given client device. It will allocate a struct from the
kernel memory to hold the pinmux state. All mapping table parsing or similar
slow operations take place within this API.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
- devm_pinctrl_get() is a variant of pinctrl_get() that causes pinctrl_put()
to be called automatically on the retrieved pointer when the associated
device is removed. It is recommended to use this function over plain
pinctrl_get().
- pinctrl_lookup_state() is called in process context to obtain a handle to a
specific state for a the client device. This operation may be slow too.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
- pinctrl_select_state() programs pin controller hardware according to the
definition of the state as given by the mapping table. In theory this is a
fast-path operation, since it only involved blasting some register settings
into hardware. However, note that some pin controllers may have their
registers on a slow/IRQ-based bus, so client devices should not assume they
can call pinctrl_select_state() from non-blocking contexts.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
- pinctrl_put() frees all information associated with a pinctrl handle.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
- devm_pinctrl_put() is a variant of pinctrl_put() that may be used to
explicitly destroy a pinctrl object returned by devm_pinctrl_get().
However, use of this function will be rare, due to the automatic cleanup
that will occur even without calling it.
pinctrl_get() must be paired with a plain pinctrl_put().
pinctrl_get() may not be paired with devm_pinctrl_put().
devm_pinctrl_get() can optionally be paired with devm_pinctrl_put().
devm_pinctrl_get() may not be paired with plain pinctrl_put().
Usually the pin control core handled the get/put pair and call out to the
device drivers bookkeeping operations, like checking available functions and
the associated pins, whereas the enable/disable pass on to the pin controller
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
driver which takes care of activating and/or deactivating the mux setting by
quickly poking some registers.
The pins are allocated for your device when you issue the devm_pinctrl_get()
call, after this you should be able to see this in the debugfs listing of all
pins.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
NOTE: the pinctrl system will return -EPROBE_DEFER if it cannot find the
requested pinctrl handles, for example if the pinctrl driver has not yet
registered. Thus make sure that the error path in your driver gracefully
cleans up and is ready to retry the probing later in the startup process.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
Drivers needing both pin control and GPIOs
==========================================
Again, it is discouraged to let drivers lookup and select pin control states
themselves, but again sometimes this is unavoidable.
So say that your driver is fetching its resources like this:
#include <linux/pinctrl/consumer.h>
#include <linux/gpio.h>
struct pinctrl *pinctrl;
int gpio;
pinctrl = devm_pinctrl_get_select_default(&dev);
gpio = devm_gpio_request(&dev, 14, "foo");
Here we first request a certain pin state and then request GPIO 14 to be
used. If you're using the subsystems orthogonally like this, you should
nominally always get your pinctrl handle and select the desired pinctrl
state BEFORE requesting the GPIO. This is a semantic convention to avoid
situations that can be electrically unpleasant, you will certainly want to
mux in and bias pins in a certain way before the GPIO subsystems starts to
deal with them.
The above can be hidden: using pinctrl hogs, the pin control driver may be
setting up the config and muxing for the pins when it is probing,
nevertheless orthogonal to the GPIO subsystem.
But there are also situations where it makes sense for the GPIO subsystem
to communicate directly with with the pinctrl subsystem, using the latter
as a back-end. This is when the GPIO driver may call out to the functions
described in the section "Pin control interaction with the GPIO subsystem"
above. This only involves per-pin multiplexing, and will be completely
hidden behind the gpio_*() function namespace. In this case, the driver
need not interact with the pin control subsystem at all.
If a pin control driver and a GPIO driver is dealing with the same pins
and the use cases involve multiplexing, you MUST implement the pin controller
as a back-end for the GPIO driver like this, unless your hardware design
is such that the GPIO controller can override the pin controller's
multiplexing state through hardware without the need to interact with the
pin control system.
System pin control hogging
==========================
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
Pin control map entries can be hogged by the core when the pin controller
is registered. This means that the core will attempt to call pinctrl_get(),
lookup_state() and select_state() on it immediately after the pin control
device has been registered.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
This occurs for mapping table entries where the client device name is equal
to the pin controller device name, and the state name is PINCTRL_STATE_DEFAULT.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
{
.dev_name = "pinctrl-foo",
.name = PINCTRL_STATE_DEFAULT,
.type = PIN_MAP_TYPE_MUX_GROUP,
.ctrl_dev_name = "pinctrl-foo",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
.function = "power_func",
},
Since it may be common to request the core to hog a few always-applicable
mux settings on the primary pin controller, there is a convenience macro for
this:
PIN_MAP_MUX_GROUP_HOG_DEFAULT("pinctrl-foo", NULL /* group */, "power_func")
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
This gives the exact same result as the above construction.
Runtime pinmuxing
=================
It is possible to mux a certain function in and out at runtime, say to move
an SPI port from one set of pins to another set of pins. Say for example for
spi0 in the example above, we expose two different groups of pins for the same
function, but with different named in the mapping as described under
"Advanced mapping" above. So that for an SPI device, we have two states named
"pos-A" and "pos-B".
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
This snippet first muxes the function in the pins defined by group A, enables
it, disables and releases it, and muxes it in on the pins defined by group B:
#include <linux/pinctrl/consumer.h>
struct pinctrl *p;
struct pinctrl_state *s1, *s2;
foo_probe()
{
/* Setup */
p = devm_pinctrl_get(&device);
if (IS_ERR(p))
...
s1 = pinctrl_lookup_state(foo->p, "pos-A");
if (IS_ERR(s1))
...
s2 = pinctrl_lookup_state(foo->p, "pos-B");
if (IS_ERR(s2))
...
}
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
foo_switch()
{
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
/* Enable on position A */
ret = pinctrl_select_state(s1);
if (ret < 0)
...
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
...
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
/* Enable on position B */
ret = pinctrl_select_state(s2);
if (ret < 0)
...
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 18:50:54 +00:00
...
}
pinctrl: reserve pins when states are activated This switches the way that pins are reserved for multiplexing: We used to do this when the map was parsed, at the creation of the settings inside the pinctrl handle, in pinmux_map_to_setting(). However this does not work for us, because we want to use the same set of pins with different devices at different times: the current code assumes that the pin groups in a pinmux state will only be used with one single device, albeit different groups can be active at different times. For example if a single I2C driver block is used to drive two different busses located on two pin groups A and B, then the pins for all possible states of a function are reserved when fetching the pinctrl handle: the I2C bus can choose either set A or set B by a mux state at runtime, but all pins in both group A and B (the superset) are effectively reserved for that I2C function and mapped to the device. Another device can never get in and use the pins in group A, even if the device/function is using group B at the moment. Instead: let use reserve the pins when the state is activated and drop them when the state is disabled, i.e. when we move to another state. This way different devices/functions can use the same pins at different times. We know that this is an odd way of doing things, but we really need to switch e.g. an SD-card slot to become a tracing output sink at runtime: we plug in a special "tracing card" then mux the pins that used to be an SD slot around to the tracing unit and push out tracing data there instead of SD-card traffic. As a side effect pinmux_free_setting() is unused but the stubs are kept for future additions of code. Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Loic Pallardy <loic.pallardy@st.com> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Jean Nicolas Graux <jean-nicolas.graux@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-10-17 18:51:54 +00:00
The above has to be done from process context. The reservation of the pins
will be done when the state is activated, so in effect one specific pin
can be used by different functions at different times on a running system.