Commit Graph

60 Commits

Author SHA1 Message Date
Jerome Brunet
93c292ef3c pwm: Silently error out on EPROBE_DEFER
In of_pwm_get(), if we fail to get the PWM chip due to probe deferal, we
shouldn't print an error message. Just be silent in this case.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-07-06 08:29:16 +02:00
Hans de Goede
b526a31426 pwm: Try to load modules during pwm_get()
Add a module name string to the pwm_lookup struct and if specified try
to load the module using request_module() if pwmchip_find_by_name() is
unable to find the PWM chip.

This is a last resort to work around drivers that can't - and can't be
made to - deal with deferred probe.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[thierry.reding@gmail.com: rename new macro, reword commit message]
[thierry.reding@gmail.com: add comment explaining use-case]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:36:42 +01:00
Hans de Goede
69efb3439c pwm: Don't hold pwm_lookup_lock longer than necessary
There is no need to hold pwm_lookup_lock after we're done with looping
over pwm_lookup_list, so release it earlier.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:19:26 +01:00
Lothar Wassmann
42883cbc08 pwm: Make the PWM_POLARITY flag in DTB optional
Change the PWM chip driver registration so that a chip driver that
supports polarity inversion can still be used with DTBs that don't
provide the polarity flag as part of the specifier.

This is done to provide polarity inversion support for the pwm-imx
driver without having to modify all existing DTS files.

Signed-off-by: Lothar Wassmann <LW@KARO-electronics.de>
Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Suggested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:13:34 +01:00
Lothar Wassmann
f2dafc0950 pwm: Print error messages with pr_err() instead of pr_debug()
Make the messages that are printed in case of fatal errors actually
visible to the user without having to recompile the driver with
debugging enabled.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:13:30 +01:00
Thierry Reding
fe2858c8c6 pwm: Remove pwm_can_sleep()
The last user of this function has been removed, so it is no longer
needed.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-04 09:39:52 +01:00
David Hsu
0733424c9b pwm: Unexport children before chip removal
Exported pwm channels aren't removed before the pwmchip and are
leaked. This results in invalid sysfs files. This fix removes
all exported pwm channels before chip removal.

Signed-off-by: David Hsu <davidhsu@google.com>
Fixes: 76abbdde2d ("pwm: Add sysfs interface")
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-05 16:45:39 +02:00
Thierry Reding
bd2686122d Merge branch 'for-4.8/capture' into for-next 2016-07-25 16:23:39 +02:00
Lee Jones
3a3d1a4e32 pwm: Add PWM capture support
Supply a PWM capture callback op in order to pass back information
obtained by running analysis on a PWM signal. This would normally (at
least during testing) be called from the sysfs routines with a view to
printing out PWM capture data which has been encoded into a string.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
[thierry.reding@gmail.com: make capture data unsigned int for symmetry]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-06-10 16:01:35 +02:00
Brian Norris
ef2bf4997f pwm: Improve args checking in pwm_apply_state()
It seems like in the process of refactoring pwm_config() to utilize the
newly-introduced pwm_apply_state() API, some args/bounds checking was
dropped.

In particular, I noted that we are now allowing invalid period
selections, e.g.:

  # echo 1 > /sys/class/pwm/pwmchip0/export
  # cat /sys/class/pwm/pwmchip0/pwm1/period
  100
  # echo 101 > /sys/class/pwm/pwmchip0/pwm1/duty_cycle
  [... driver may or may not reject the value, or trigger some logic bug ...]

It's better to see:

  # echo 1 > /sys/class/pwm/pwmchip0/export
  # cat /sys/class/pwm/pwmchip0/pwm1/period
  100
  # echo 101 > /sys/class/pwm/pwmchip0/pwm1/duty_cycle
  -bash: echo: write error: Invalid argument

This patch reintroduces some bounds checks in both pwm_config() (for its
signed parameters; we don't want to convert negative values into large
unsigned values) and in pwm_apply_state() (which fix the above described
behavior, as well as other potential API misuses).

Fixes: 5ec803edcb ("pwm: Add core infrastructure to allow atomic updates")
Signed-off-by: Brian Norris <briannorris@chromium.org>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-06-10 14:21:00 +02:00
Thierry Reding
18c588786c Merge branch 'for-4.7/pwm-atomic' into for-next 2016-05-17 14:57:58 +02:00
Thierry Reding
bf5dd9abcb Merge branch 'for-4.7/pwm-args' into for-next 2016-05-17 14:57:47 +02:00
Heiko Stübner
23e3523f5d pwm: Add information about polarity, duty cycle and period to debugfs
The PWM states make it possible to also output the polarity, duty cycle
and period information in the debugfs summary output. This simplifies
gathering information about PWMs without needing to walk through the
sysfs attributes of every PWM.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[thierry.reding@gmail.com: use more spaces in debugfs output]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17 14:48:05 +02:00
Boris Brezillon
39100ceea7 pwm: Switch to the atomic API
Replace legacy pwm_get/set_xxx() and pwm_config/enable/disable() calls
by pwm_get/apply_state().

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17 14:48:04 +02:00
Boris Brezillon
5ec803edcb pwm: Add core infrastructure to allow atomic updates
Add an ->apply() method to the pwm_ops struct to allow PWM drivers to
implement atomic updates. This method is preferred over the ->enable(),
->disable() and ->config() methods if available.

Add the pwm_apply_state() function to the PWM user API.

Note that the pwm_apply_state() does not guarantee the atomicity of the
update operation, it all depends on the availability and implementation
of the ->apply() method.

pwm_enable/disable/set_polarity/config() are now implemented as wrappers
around the pwm_apply_state() function.

pwm_adjust_config() is allowing smooth handover between the bootloader
and the kernel. This function tries to adapt the current PWM state to
the PWM arguments coming from a PWM lookup table or a DT definition
without changing the duty_cycle/period proportion.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[thierry.reding@gmail.com: fix a couple of typos]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17 14:48:03 +02:00
Boris Brezillon
15fa8a43c1 pwm: Add hardware readout infrastructure
Add a ->get_state() function to the pwm_ops struct to let PWM drivers
initialize the PWM state attached to a PWM device.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17 14:48:03 +02:00
Boris Brezillon
09a7e4a3d9 pwm: Move the enabled/disabled info into pwm_state
Prepare the transition to PWM atomic update by moving the enabled and
disabled state into the pwm_state struct. This way we can easily update
the whole PWM state by copying the new state in the ->state field.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17 14:48:02 +02:00
Boris Brezillon
43a276b003 pwm: Introduce the pwm_state concept
The PWM state, represented by its period, duty_cycle and polarity is
currently directly stored in the PWM device. Declare a pwm_state
structure embedding those field so that we can later use this struct
to atomically update all the PWM parameters at once.

All pwm_get_xxx() helpers are now implemented as wrappers around
pwm_get_state().

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17 14:48:02 +02:00
Boris Brezillon
a8c3862551 pwm: Keep PWM state in sync with hardware state
Before the introduction of pwm_args, the core was resetting the PWM
period and polarity states to the reference values (those provided
through the DT, a PWM lookup table or hardcoded in the driver).

Now that all PWM users are correctly using pwm_args to configure their
PWM device, we can safely remove the pwm_apply_args() call in pwm_get()
and of_pwm_get().

We can also get rid of the pwm_set_period() call in pwm_apply_args(),
because PWM users are now directly using pargs->period instead of
pwm_get_period(). By doing that we avoid messing with the current PWM
period.

The only remaining bit in pwm_apply_args() is the initial polarity
setting, and it should go away when all PWM users have been patched to
use the atomic API (with this API the polarity will be set along with
other PWM arguments when configuring the PWM).

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17 14:47:30 +02:00
Boris BREZILLON
459a25afe9 pwm: Get rid of pwm->lock
PWM devices are not protected against concurrent accesses. The lock in
struct pwm_device might let PWM users think it is, but it's actually
only protecting the enabled state.

Removing this lock should be fine as long as all PWM users are aware
that accesses to the PWM device have to be serialized, which seems to be
the case for all of them except the sysfs interface. Patch the sysfs
code by adding a lock to the pwm_export struct and making sure it's
taken for all relevant accesses to the exported PWM device.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17 14:44:59 +02:00
Boris Brezillon
fbd45a1298 pwm: Fix pwm_apply_args() call sites
pwm_apply_args() is supposed to initialize a PWM device according to the
arguments provided by the DT or the PWM lookup, but this function was
called inside pwm_device_request(), which in turn was called before the
core had a chance to initialize the pwm->args fields.

Fix that by calling pwm_apply_args directly in pwm_get() and of_pwm_get()
after initializing pwm->args field.

This commit also fixes an invalid pointer dereference introduced by
commit e39c0df1be ("pwm: Introduce the pwm_args concept").

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Fixes: e39c0df1be ("pwm: Introduce the pwm_args concept")
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17 14:41:18 +02:00
Thierry Reding
2907f8abb7 pwm: Use kcalloc() instead of kzalloc()
kcalloc() should be preferred for allocations of arrays over kzalloc()
with multiplication.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-03 13:57:05 +02:00
Thierry Reding
83a98864ff pwm: Add missing newline
checkpatch requires that declarations be separated from code by a blank
line. Add one for readability and to silence the warning.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-03 13:57:03 +02:00
Boris Brezillon
e39c0df1be pwm: Introduce the pwm_args concept
Currently the PWM core mixes the current PWM state with the per-platform
reference config (specified through the PWM lookup table, DT definition
or directly hardcoded in PWM drivers).

Create a struct pwm_args to store this reference configuration, so that
PWM users can differentiate between the current and reference
configurations.

Patch all places where pwm->args should be initialized. We keep the
pwm_set_polarity/period() calls until all PWM users are patched to use
pwm_args instead of pwm_get_period/polarity().

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[thierry.reding@gmail.com: reword kerneldoc comments]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-03 13:44:37 +02:00
Thierry Reding
ff01c944cf pwm: Mark all devices as "might sleep"
Commit d1cd214277 ("pwm: Set enable state properly on failed call to
enable") introduced a mutex that is needed to protect internal state of
PWM devices. Since that mutex is acquired in pwm_set_polarity() and in
pwm_enable() and might potentially block, all PWM devices effectively
become "might sleep".

It's rather pointless to keep the .can_sleep field around, but given
that there are external users let's postpone the removal for the next
release cycle.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-01-21 15:04:59 +01:00
Thierry Reding
655a03554c pwm: Return -ENODEV if no PWM lookup match is found
When looking up a PWM using the lookup table, assume that all entries
will have been added already, so failure to find a match means that no
corresponding entry has been registered.

This fixes an issue where -EPROBE_DEFER would be returned if the PWM
lookup table is empty. After this fix, -EPROBE_DEFER is reserved for
situations where no provider has yet registered for a matching entry.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-10 13:06:42 +01:00
Jonathan Richardson
d1cd214277 pwm: Set enable state properly on failed call to enable
The pwm_enable() function didn't clear the enabled bit if a call to the
driver's ->enable() callback returned an error. The result was that the
state of the PWM core was wrong. Clearing the bit when enable returns
an error ensures the state is properly set.

Tested-by: Jonathan Richardson <jonathar@broadcom.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jonathan Richardson <jonathar@broadcom.com>
[thierry.reding@gmail.com: add missing kerneldoc for the lock]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-10 13:06:16 +01:00
Thierry Reding
0488380276 pwm: Clean up kerneldoc
Clean up kerneldoc in preparation for including the PWM documentation in
DocBook.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-08-17 15:40:20 +02:00
Thierry Reding
6bc7064a69 pwm: Remove useless whitespace
Remove useless tabs used for padding in structure definitions as well as
some blank lines.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-08-17 15:40:19 +02:00
Boris Brezillon
5c31252c4a pwm: Add the pwm_is_enabled() helper
Some PWM drivers are testing the PWMF_ENABLED flag. Create a helper
function to hide the logic behind enabled test. This will allow us to
smoothly move from the current approach to an atomic PWM update
approach.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-07-20 09:46:06 +02:00
Tim Kryger
b6a00fae97 pwm: Add pwmchip_add_with_polarity() API
Add a new function to register a PWM chip with channels that have their
initial polarity as specified by an additional parameter. This benefits
drivers of controllers that by default operate with inversed polarity
by removing the need to modify the polarity during initialization.

Signed-off-by: Tim Kryger <tim.kryger@gmail.com>
Signed-off-by: Jonathan Richardson <jonathar@broadcom.com>
[thierry.reding@gmail.com: export pwmchip_add_with_polarity()]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-06-12 11:36:30 +02:00
Shobhit Kumar
efb0de55b6 pwm: Add support to remove registered consumer lookup tables
In case some drivers are unloading, they can remove lookup tables which
they had registered during their load time to avoid redundant entries if
loaded again.

CC: Samuel Ortiz <sameo@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-05-06 14:19:35 +02:00
Shobhit Kumar
c264f1110d pwm: Remove __init initializer for pwm_add_table()
For platforms that don't support DT, some early MFD modules can register
lookup tables. Remove the __init annotation so that this works. This is
similar to gpio_add_lookup_table() which allows late additions.

CC: Samuel Ortiz <sameo@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-04-23 14:50:52 +02:00
Markus Elfring
8d6cc07385 pwm: Remove unnecessary check before of_node_put()
The of_node_put() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-02-03 12:56:54 +01:00
Geert Uytterhoeven
70145f8713 pwm: Fix uninitialized warnings in pwm_get()
With some versions of gcc (e.g. 4.1.2):

drivers/pwm/core.c: In function ‘pwm_get’:
drivers/pwm/core.c:610: warning: ‘polarity’ may be used uninitialized in this function
drivers/pwm/core.c:609: warning: ‘period’ may be used uninitialized in this function

While these are false positives, we can get rid of them by refactoring
the code to store a pointer to the best match, as suggested before by
Thierry Reding. This does require moving the mutex_unlock() down.

Fixes: d717ea73e3 ("pwm: Fix period and polarity in pwm_get() for non-perfect matches")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-29 10:18:19 +02:00
Xiubo Li
533acc0e8d pwm: Fix possible ZERO_SIZE_PTR pointer dereferencing error.
Since we cannot make sure the 'chip->npwm' will always be none zero here,
and then if either equal to zero, the kzalloc() will return ZERO_SIZE_PTR,
which equals to ((void *)16).

So this patch fix this with just doing the zero check before calling kzalloc().

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-25 14:38:12 +02:00
Geert Uytterhoeven
d717ea73e3 pwm: Fix period and polarity in pwm_get() for non-perfect matches
If pwm_get() finds a look-up entry with a perfect match (both dev_id and
con_id match), the loop is aborted, and "p" still points to the correct
struct pwm_lookup.

If only an entry with a matching dev_id or con_id is found, the loop
terminates after traversing the whole list, and "p" now points to
arbitrary memory, not part of the pwm_lookup list.
Then pwm_set_period() and pwm_set_polarity() will set random values for
period resp. polarity.

To fix this, save period and polarity when finding a new best match,
just like is done for chip (for the provider) and index.

This fixes the LCD backlight on r8a7740/armadillo-legacy, which was fed
period 0 and polarity -1068821144 instead of 33333 resp. 1.

Fixes: 3796ce1d4d ("pwm: add period and polarity to struct pwm_lookup")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable@vger.kernel.org
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-18 10:58:43 +02:00
Alexandre Belloni
3796ce1d4d pwm: add period and polarity to struct pwm_lookup
Add period and polarity members to struct pwm_lookup so that platforms
using the lookup table can be treated the same way as those using the
device tree.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-05-21 09:03:07 +02:00
Jingoo Han
adcba1e3a5 pwm: use seq_puts() instead of seq_printf()
For a constant format without additional arguments, use seq_puts()
instead of seq_printf(). Also, the following checkpatch warning is
fixed.

  WARNING: Prefer seq_puts to seq_printf

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-12-20 10:53:41 +01:00
Laurent Pinchart
208be7698f pwm: Use the DT macro directly when parsing PWM DT flags
Don't redefine a PWM_SPEC_POLARITY macro with a value identical to
PWM_POLARITY_INVERTED, use the PWM DT macro directly.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-09-03 13:08:10 +02:00
H Hartley Sweeten
76abbdde2d pwm: Add sysfs interface
Add a simple sysfs interface to the generic PWM framework.

  /sys/class/pwm/
  `-- pwmchipN/           for each PWM chip
      |-- export          (w/o) ask the kernel to export a PWM channel
      |-- npwm            (r/o) number of PWM channels in this PWM chip
      |-- pwmX/           for each exported PWM channel
      |   |-- duty_cycle  (r/w) duty cycle (in nanoseconds)
      |   |-- enable      (r/w) enable/disable PWM
      |   |-- period      (r/w) period (in nanoseconds)
      |   `-- polarity    (r/w) polarity of PWM (normal/inversed)
      `-- unexport        (w/o) return a PWM channel to the kernel

Based on work by Lars Poeschel.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Lars Poeschel <poeschel@lemonage.de>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-06-21 11:32:51 +02:00
Wolfram Sang
77f0b9d2ff pwm: devm: alloc correct pointer size
The allocated object should be the size of what the pointer is pointing
to and not the size of the pointer itself.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-06-10 12:50:10 +02:00
Linus Torvalds
3eb05225ee pwm: Changes for v3.9-rc1
A new driver has been added to support the PWM mode of the timer counter
 blocks found on Atmel AT91 SoCs. The VT8500 driver now supports changing
 the PWM signal polarity and the TI drivers (EHRPWM and ECAP) gained
 suspend and resume functionality.
 
 User drivers can now query the core for whether access to a PWM device
 will sleep (if the PWM chip is on a slow bus such as I2C or SPI).
 
 The pwm-backlight driver now handles the backlight BL_CORE_FBBLANK state
 in addition to the FB layer's blanking states.
 
 To round things off, a few fixes and cleanups are also included.
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Merge tag 'for-3.9-rc1' of git://gitorious.org/linux-pwm/linux-pwm

Pull PWM changes from Thierry Reding:
 "A new driver has been added to support the PWM mode of the timer
  counter blocks found on Atmel AT91 SoCs.  The VT8500 driver now
  supports changing the PWM signal polarity and the TI drivers (EHRPWM
  and ECAP) gained suspend and resume functionality.

  User drivers can now query the core for whether access to a PWM device
  will sleep (if the PWM chip is on a slow bus such as I2C or SPI).

  The pwm-backlight driver now handles the backlight BL_CORE_FBBLANK
  state in addition to the FB layer's blanking states.

  To round things off, a few fixes and cleanups are also included"

* tag 'for-3.9-rc1' of git://gitorious.org/linux-pwm/linux-pwm:
  pwm: twl: Use to_twl() instead of container_of()
  pwm: tegra: assume CONFIG_OF
  pwm_backlight: Validate dft_brightness in main probe function
  pwm: Export pwm_{set,get}_chip_data()
  pwm: Make Kconfig entries more consistent
  pwm: Add can_sleep property to drivers
  pwm: Add pwm_can_sleep() as exported API to users
  pwm-backlight: handle BL_CORE_FBBLANK state
  pwm: pwm-tiecap: Low power sleep support
  pwm: pwm-tiehrpwm: Low power sleep support
  pwm: pwm-tiehrpwm: Update the clock handling of pwm-tiehrpwm driver
  pwm: vt8500: Add polarity support
  pwm: vt8500: Register write busy test performed incorrectly
  pwm: atmel: add Timer Counter Block PWM driver
2013-02-26 09:34:29 -08:00
Peter Ujfalusi
261a5edd3a pwm: Add devm_of_pwm_get() as exported API for users
When booted with DT users can use devm version of of_pwm_get() to benefit
from automatic resource release.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
2013-02-01 17:47:05 -08:00
Peter Ujfalusi
8eb9612799 pwm: core: Rename of_pwm_request() to of_pwm_get() and export it
Allow client driver to use of_pwm_get() to get the PWM they need. This
is needed for drivers which handle more than one PWM separately, like
leds-pwm driver, which have:

pwmleds {
	compatible = "pwm-leds";
	kpad {
		label = "omap4::keypad";
		pwms = <&twl_pwm 0 7812500>;
		max-brightness = <127>;
	};

	charging {
		label = "omap4:green:chrg";
		pwms = <&twl_pwmled 0 7812500>;
		max-brightness = <255>;
	};
};

in the dts files.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
2013-02-01 17:47:05 -08:00
Thierry Reding
928c44775b pwm: Export pwm_{set,get}_chip_data()
When building a driver as a module, these functions need to be exported
for linking to succeed.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2013-01-30 09:22:24 +01:00
Florian Vaussard
6e69ab1361 pwm: Add pwm_can_sleep() as exported API to users
Calls to some external PWM chips can sleep. To help users,
add pwm_can_sleep() API.

Cc: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2013-01-30 09:12:18 +01:00
Thierry Reding
417328c3f7 pwm: Export of_pwm_xlate_with_flags()
Drivers may want to use this function if they support any of the flags
that can be passed via a third cell in the DT specifier. Since those
drivers may be built as modules the symbol needs to be exported to make
sure that it can be accessed.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-12-06 08:51:38 +01:00
Philip, Avinash
83af24027b pwm: Device tree support for PWM polarity
Add support for encoding PWM properties in bit encoded form with
of_pwm_xlate_with_flags() function support. Platforms require platform
specific PWM properties has to populate in 3rd cell of the pwm-specifier
and PWM driver should also set .of_xlate support with this function.
Currently PWM property polarity encoded in bit position 0 of the third
cell in pwm-specifier.

Signed-off-by: Philip, Avinash <avinashphilip@ti.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-11-22 22:47:12 +01:00
Thierry Reding
c2d476a98f pwm: Check for negative duty-cycle and period
Make sure the duty-cycle and period passed in are not negative. This
should eventually be made implicit by making them unsigned. While at
it, the drivers' .config() implementations can have the equivalent
checks removed.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Axel Lin <axel.lin@gmail.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Jonghwan Choi <jhbird.choi@samsung.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: "Philip, Avinash" <avinashphilip@ti.com>
Cc: Vaibhav Bedia <vaibhav.bedia@ti.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
2012-10-05 20:56:43 +02:00