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109 Commits

Author SHA1 Message Date
William Breathitt Gray
663d8fb0f8 counter: 104-quad-8: Fix use-after-free by quad8_irq_handler 
On unbind an irq might be pending which results in quad8_irq_handler()
calling counter_push_event() for a counter that is already unregistered.
This patch fixes that situation by passing the struct counter_device dev
to devm_request_irq() rather than the parent's so that the irq handler
is cleaned before the counter is unregistered.

Fixes: 7aa2ba0df6 ("counter: 104-quad-8: Add IRQ support for the ACCES 104-QUAD-8")
Cc: Syed Nayyar Waris <syednwaris@gmail.com>
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20220105093052.258791-1-vilhelm.gray@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2022-01-06 15:51:13 +01:00
Uwe Kleine-König
f2ee4759fb counter: remove old and now unused registration API 
Usage of counter_register() yields issues in device lifetime tracking. All
drivers were converted to the new API, so the old one can go away.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-24-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:07 +01:00
Uwe Kleine-König
02758cb20d counter: ti-eqep: Convert to new counter registration 
This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: f213729f67 ("counter: new TI eQEP driver")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: David Lechner <david@lechnology.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-23-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:07 +01:00
Uwe Kleine-König
e75d678d04 counter: stm32-lptimer-cnt: Convert to new counter registration 
This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: 597f55e3f3 ("counter: stm32-lptimer: add counter device")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-22-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:07 +01:00
Uwe Kleine-König
e1717d2ea0 counter: stm32-timer-cnt: Convert to new counter registration 
This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: ad29937e20 ("counter: Add STM32 Timer quadrature encoder")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-21-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:07 +01:00
Uwe Kleine-König
5998ea6214 counter: microchip-tcb-capture: Convert to new counter registration 
This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: 106b104137 ("counter: Add microchip TCB capture counter")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-20-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:07 +01:00
Uwe Kleine-König
b5d6547c8e counter: ftm-quaddec: Convert to new counter registration 
This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: a3b9a99980 ("counter: add FlexTimer Module Quadrature decoder counter driver")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-19-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:07 +01:00
Uwe Kleine-König
e99dec87a9 counter: intel-qep: Convert to new counter registration 
This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: b711f687a1 ("counter: Add support for Intel Quadrature Encoder Peripheral")
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-18-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:07 +01:00
Uwe Kleine-König
aefc7e1797 counter: interrupt-cnt: Convert to new counter registration 
This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: a55ebd47f2 ("counter: add IRQ or GPIO based counter")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-17-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:07 +01:00
Uwe Kleine-König
9e884bb19c counter: 104-quad-8: Convert to new counter registration 
This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: f1d8a071d4 ("counter: 104-quad-8: Add Generic Counter interface support")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-16-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:07 +01:00
Uwe Kleine-König
c18e276030 counter: Provide alternative counter registration functions 
The current implementation gets device lifetime tracking wrong. The
problem is that allocation of struct counter_device is controlled by the
individual drivers but this structure contains a struct device that
might have to live longer than a driver is bound. As a result a command
sequence like:

	{ sleep 5; echo bang; } > /dev/counter0 &
	sleep 1;
	echo 40000000.timer:counter > /sys/bus/platform/drivers/stm32-timer-counter/unbind

can keep a reference to the struct device and unbinding results in
freeing the memory occupied by this device resulting in an oops.

This commit provides two new functions (plus some helpers):
 - counter_alloc() to allocate a struct counter_device that is
   automatically freed once the embedded struct device is released
 - counter_add() to register such a device.

Note that this commit doesn't fix any issues, all drivers have to be
converted to these new functions to correct the lifetime problems.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-14-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
e152833b2c counter: stm32-timer-cnt: Convert to counter_priv() wrapper 
This is a straight forward conversion to the new counter_priv() wrapper.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-13-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
e98ea385f8 counter: stm32-lptimer-cnt: Convert to counter_priv() wrapper 
This is a straight forward conversion to the new counter_priv() wrapper.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-12-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
8817c2d03a counter: ti-eqep: Convert to counter_priv() wrapper 
This is a straight forward conversion to the new counter_priv() wrapper.

Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: David Lechner <david@lechnology.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-11-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
1f1b40c057 counter: ftm-quaddec: Convert to counter_priv() wrapper 
This is a straight forward conversion to the new counter_priv() wrapper.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-10-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
53ada09552 counter: intel-qep: Convert to counter_priv() wrapper 
This is a straight forward conversion to the new counter_priv() wrapper.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-9-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
a49ede8208 counter: microchip-tcb-capture: Convert to counter_priv() wrapper 
This is a straight forward conversion to the new counter_priv() wrapper.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-8-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
63f0e2b6c0 counter: interrupt-cnt: Convert to counter_priv() wrapper 
This is a straight forward conversion to the new counter_priv() wrapper.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-7-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
aea8334b24 counter: 104-quad-8: Convert to counter_priv() wrapper 
This is a straight forward conversion to the new counter_priv() wrapper.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
5207fb2f31 counter: Provide a wrapper to access device private data 
For now this just wraps accessing struct counter_device::priv. However
this is about to change and converting drivers to this helper
individually makes fixing device lifetime issues result in easier to
review patches.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-5-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
0880603c84 counter: microchip-tcb-capture: Drop unused platform_set_drvdata() 
The driver doesn't ever use platform_get_drvdata, so drop this unused
call.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:06 +01:00
Uwe Kleine-König
8b2bc10ca2 counter: ftm-quaddec: Drop unused platform_set_drvdata() 
The driver doesn't ever use platform_get_drvdata, so drop this unused
call.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:05 +01:00
Uwe Kleine-König
b56346ddbd counter: Use container_of instead of drvdata to track counter_device 
The counter core uses drvdata to find a struct counter_device from a
struct device. However as the device is a member of struct counter_device,
the lookup can be done faster (and a bit type safe) using container_of.

There are no other users of drvdata, so the call to dev_set_drvdata can
go away, too.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211230150300.72196-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-30 17:44:05 +01:00
William Breathitt Gray
c95cc0d957 counter: 104-quad-8: Fix persistent enabled events bug 
A bug exists if the user executes a COUNTER_ADD_WATCH_IOCTL ioctl call,
and then executes a COUNTER_DISABLE_EVENTS_IOCTL ioctl call. Disabling
the events should disable the 104-QUAD-8 interrupts, but because of this
bug the interrupts are not disabling.

The reason this bug is occurring is because quad8_events_configure() is
called when COUNTER_DISABLE_EVENTS_IOCTL is handled, but the
next_irq_trigger[] array has not been cleared before it is checked in
the loop.

This patch fixes the bug by removing the next_irq_trigger array and
instead utilizing a different algorithm of walking the events_list list
for the current requested events. When a COUNTER_DISABLE_EVENTS_IOCTL is
handled, events_list will be empty and thus all device channels end up
with interrupts disabled.

Fixes: 7aa2ba0df6 ("counter: 104-quad-8: Add IRQ support for the ACCES 104-QUAD-8")
Cc: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/5fd5731cec1c251acee30eefb7c19160d03c9d39.1640072891.git.vilhelm.gray@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-21 10:32:08 +01:00
Uwe Kleine-König
60f07e74f8 counter: ti-eqep: Use container_of instead of struct counter_device::priv 
Using counter->priv is a memory read and so more expensive than
container_of which is only an addition. (In this case even a noop
because the offset is 0.)

So container_of is expected to be a tad faster, it's type-safe, and
produces smaller code (ARCH=arm allmodconfig):

	$ source/scripts/bloat-o-meter drivers/counter/ti-eqep.o-pre drivers/counter/ti-eqep.o
	add/remove: 0/0 grow/shrink: 0/9 up/down: 0/-108 (-108)
	Function                                     old     new   delta
	ti_eqep_position_enable_write                132     120     -12
	ti_eqep_position_enable_read                 260     248     -12
	ti_eqep_position_ceiling_write               132     120     -12
	ti_eqep_position_ceiling_read                236     224     -12
	ti_eqep_function_write                       220     208     -12
	ti_eqep_function_read                        372     360     -12
	ti_eqep_count_write                          312     300     -12
	ti_eqep_count_read                           236     224     -12
	ti_eqep_action_read                          664     652     -12
	Total: Before=4598, After=4490, chg -2.35%

Acked-by: David Lechner <david@lechnology.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/4bde7cbd9e43a5909208102094444219d3154466.1640072891.git.vilhelm.gray@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-12-21 10:32:08 +01:00
William Breathitt Gray
8ac33b8b68 counter: Fix use-after-free race condition for events_queue_size write 
A race condition is possible when writing to events_queue_size where the
events kfifo is freed during the execution of a kfifo_in(), resulting in
a use-after-free. This patch prevents such a scenario by protecting the
events queue in operation with a spinlock and locking before performing
the events queue size adjustment.

The existing events_lock mutex is renamed to events_out_lock to reflect
that it only protects events queue out operations. Because the events
queue in operations can occur in an interrupt context, a new
events_in_lock spinlock is introduced and utilized.

Fixes: feff17a550 ("counter: Implement events_queue_size sysfs attribute")
Cc: David Lechner <david@lechnology.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20211021103540.955639-1-vilhelm.gray@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-10-21 13:02:47 +02:00
William Breathitt Gray
310e75c72f counter: Cleanup lingering atomic.h includes 
With the removal of the chrdev_lock atomic flag, the counter-sysfs.c and
counter-chrdev.c no longer needs to include the atomic.h header file.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20211021103514.955622-1-vilhelm.gray@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-10-21 13:02:45 +02:00
David Lechner
f5245a5fdf counter: drop chrdev_lock 
This removes the chrdev_lock from the counter subsystem. This was
intended to prevent opening the chrdev more than once. However, this
doesn't work in practice since userspace can duplicate file descriptors
and pass file descriptors to other processes. Since this protection
can't be relied on, it is best to just remove it.

Suggested-by: Greg KH <gregkh@linuxfoundation.org>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: David Lechner <david@lechnology.com>
Link: https://lore.kernel.org/r/20211017185521.3468640-1-david@lechnology.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-10-19 11:36:28 +02:00
David Lechner
c3ed761c9e counter/counter-sysfs: use sysfs_emit everywhere 
In the counter subsystem, we are already using sysfs_emit(), but there
were a few places where we were still using sprintf() in *_show()
functions. For consistency and added protections, use sysfs_emit()
everywhere.

Suggested-by: Greg KH <gregkh@linuxfoundation.org>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: David Lechner <david@lechnology.com>
Link: https://lore.kernel.org/r/20211017190106.3472645-1-david@lechnology.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2021-10-19 09:40:49 +02:00
Jonathan Cameron
fe90fcabc8 counter: microchip-tcb-capture: Tidy up a false kernel-doc /** marking. 
Deals with
W=1 warning This comment starts with '/**', but isn't a kernel-doc comment.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kamel Bouhara <kamel.bouhara@bootlin.com>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20210930170347.101153-1-jic23@kernel.org
 2021-10-17 10:56:31 +01:00
William Breathitt Gray
7aa2ba0df6 counter: 104-quad-8: Add IRQ support for the ACCES 104-QUAD-8 
The LSI/CSI LS7266R1 chip provides programmable output via the FLG pins.
When interrupts are enabled on the ACCES 104-QUAD-8, they occur whenever
FLG1 is active. Four functions are available for the FLG1 signal: Carry,
Compare, Carry-Borrow, and Index.

	Carry:
		Interrupt generated on active low Carry signal. Carry
		signal toggles every time the respective channel's
		counter overflows.

	Compare:
		Interrupt generated on active low Compare signal.
		Compare signal toggles every time respective channel's
		preset register is equal to the respective channel's
		counter.

	Carry-Borrow:
		Interrupt generated on active low Carry signal and
		active low Borrow signal. Carry signal toggles every
		time the respective channel's counter overflows. Borrow
		signal toggles every time the respective channel's
		counter underflows.

	Index:
		Interrupt generated on active high Index signal.

These four functions correspond respectivefly to the following four
Counter event types: COUNTER_EVENT_OVERFLOW, COUNTER_EVENT_THRESHOLD,
COUNTER_EVENT_OVERFLOW_UNDERFLOW, and COUNTER_EVENT_INDEX. Interrupts
push Counter events to event channel X, where 'X' is the respective
channel whose FLG1 activated.

This patch adds IRQ support for the ACCES 104-QUAD-8. The interrupt line
numbers for the devices may be configured via the irq array module
parameter.

Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/e3a28e100840e3a336fa93fce77445f0e9d9a674.1632884256.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-10-17 10:55:55 +01:00
William Breathitt Gray
09db4678bf counter: 104-quad-8: Replace mutex with spinlock 
This patch replaces the mutex I/O lock with a spinlock. This is in
preparation for a subsequent patch adding IRQ support for 104-QUAD-8
devices; we can't sleep in an interrupt context, so we'll need to use a
spinlock instead.

Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/3f74491dec66de10d062978bcb7b9c2b3bdea86c.1632884256.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-10-17 10:55:43 +01:00
William Breathitt Gray
feff17a550 counter: Implement events_queue_size sysfs attribute 
The events_queue_size sysfs attribute provides a way for users to
dynamically configure the Counter events queue size for the Counter
character device interface. The size is in number of struct
counter_event data structures. The number of elements will be rounded-up
to a power of 2 due to a requirement of the kfifo_alloc function called
during reallocation of the queue.

Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/c914b2db2ea0a2637633bcc3e86ded3c94783f2e.1632884256.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-10-17 10:55:01 +01:00
William Breathitt Gray
4bdec61d92 counter: Implement *_component_id sysfs attributes 
The Generic Counter chrdev interface expects users to supply component
IDs in order to select extensions for requests. In order for users to
know what component ID belongs to which extension this information must
be exposed. The *_component_id attribute provides a way for users to
discover what component ID belongs to which respective extension.

Cc: David Lechner <david@lechnology.com>
Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/8961a11edbb882fc689e468194f5be75f572443e.1632884256.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-10-17 10:54:48 +01:00
William Breathitt Gray
bb6264a61d counter: Implement signalZ_action_component_id sysfs attribute 
The Generic Counter chrdev interface expects users to supply component
IDs in order to select Synapses for requests. In order for users to know
what component ID belongs to which Synapse this information must be
exposed. The signalZ_action_component_id attribute provides a way for
users to discover what component ID belongs to the respective Synapse.

Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Lechner <david@lechnology.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/a6c81b2f1f5d0b8d59b1ebe4f0fed04914b07547.1632884256.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-10-17 10:54:36 +01:00
William Breathitt Gray
b6c50affda counter: Add character device interface 
This patch introduces a character device interface for the Counter
subsystem. Device data is exposed through standard character device read
operations. Device data is gathered when a Counter event is pushed by
the respective Counter device driver. Configuration is handled via ioctl
operations on the respective Counter character device node.

Cc: David Lechner <david@lechnology.com>
Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/b8b8c64b4065aedff43699ad1f0e2f8d1419c15b.1632884256.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-10-17 10:53:52 +01:00
William Breathitt Gray
712392f558 counter: Update counter.h comments to reflect sysfs internalization 
The Counter subsystem architecture and driver implementations have
changed in order to handle Counter sysfs interactions in a more
consistent way. This patch updates the Generic Counter interface
header file comments to reflect the changes.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/19da8ae0c05381b0967c8a334b67f86b814eb880.1630031207.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-10-17 10:53:11 +01:00
William Breathitt Gray
aaec1a0f76 counter: Internalize sysfs interface code 
This is a reimplementation of the Generic Counter driver interface.
There are no modifications to the Counter subsystem userspace interface,
so existing userspace applications should continue to run seamlessly.

The purpose of this patch is to internalize the sysfs interface code
among the various counter drivers into a shared module. Counter drivers
pass and take data natively (i.e. u8, u64, etc.) and the shared counter
module handles the translation between the sysfs interface and the
device drivers. This guarantees a standard userspace interface for all
counter drivers, and helps generalize the Generic Counter driver ABI in
order to support the Generic Counter chrdev interface (introduced in a
subsequent patch) without significant changes to the existing counter
drivers.

Note, Counter device registration is the same as before: drivers
populate a struct counter_device with components and callbacks, then
pass the structure to the devm_counter_register function. However,
what's different now is how the Counter subsystem code handles this
registration internally.

Whereas before callbacks would interact directly with sysfs data, this
interaction is now abstracted and instead callbacks interact with native
C data types. The counter_comp structure forms the basis for Counter
extensions.

The counter-sysfs.c file contains the code to parse through the
counter_device structure and register the requested components and
extensions. Attributes are created and populated based on type, with
respective translation functions to handle the mapping between sysfs and
the counter driver callbacks.

The translation performed for each attribute is straightforward: the
attribute type and data is parsed from the counter_attribute structure,
the respective counter driver read/write callback is called, and sysfs
I/O is handled before or after the driver read/write function is called.

Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: Patrick Havelange <patrick.havelange@essensium.com>
Cc: Kamel Bouhara <kamel.bouhara@bootlin.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Reviewed-by: David Lechner <david@lechnology.com>
Tested-by: David Lechner <david@lechnology.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com> # for stm32
Link: https://lore.kernel.org/r/c68b4a1ffb195c1a2f65e8dd5ad7b7c14e79c6ef.1630031207.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-10-17 10:52:58 +01:00
William Breathitt Gray
ea434ff826 counter: stm32-timer-cnt: Provide defines for slave mode selection 
The STM32 timer permits configuration of the counter encoder mode via
the slave mode control register (SMCR) slave mode selection (SMS) bits.
This patch provides preprocessor defines for the supported encoder
modes.

Cc: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/ad3d9cd7af580d586316d368f74964cbc394f981.1630031207.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-10-17 10:52:46 +01:00
William Breathitt Gray
05593a3fd1 counter: stm32-lptimer-cnt: Provide defines for clock polarities 
The STM32 low-power timer permits configuration of the clock polarity
via the LPTIMX_CFGR register CKPOL bits. This patch provides
preprocessor defines for the supported clock polarities.

Cc: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/a111c8905c467805ca530728f88189b59430f27e.1630031207.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-10-17 10:52:29 +01:00
William Breathitt Gray
94a853eca7 counter: 104-quad-8: Describe member 'lock' in 'quad8' 
This adds a kernel-doc comment line describing the 'lock' member of the
'quad8' structure.

Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/43b4acab9e238638c7067dd4a363a42f94c94ccb.1628511445.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-08-09 20:24:38 +01:00
William Breathitt Gray
394a0150a0 counter: Rename counter_count_function to counter_function 
The phrase "Counter Count function" is verbose and unintentionally
implies that function is a Count extension. This patch adjusts the
Counter subsystem code to use the more direct "Counter function" phrase
to make the intent of this code clearer.

Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: Patrick Havelange <patrick.havelange@essensium.com>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Kamel Bouhara <kamel.bouhara@bootlin.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: David Lechner <david@lechnology.com>
Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/8268c54d6f42075a19bb08151a37831e22652499.1627990337.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-08-09 20:17:36 +01:00
William Breathitt Gray
493b938a14 counter: Rename counter_signal_value to counter_signal_level 
Signal values will always be levels so let's be explicit it about it to
make the intent of the code clear.

Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Kamel Bouhara <kamel.bouhara@bootlin.com>
Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Reviewed-by: David Lechner <david@lechnology.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/3f17010abe2415859cea9a5fddabd3c97f635ff5.1627990337.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-08-09 20:17:36 +01:00
William Breathitt Gray
e2ff3198c5 counter: Standardize to ERANGE for limit exceeded errors 
ERANGE is a semantically better error code to return when an argument
value falls outside the supported limit range of a device.

Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Reviewed-by: David Lechner <david@lechnology.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/ae8d3b20b8b02c96b1c9898ffa2f9fa5d99edc81.1627990337.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-08-09 20:17:36 +01:00
William Breathitt Gray
b11eed1554 counter: Return error code on invalid modes 
Only a select set of modes (function, action, etc.) are valid for a
given device configuration. This patch ensures that invalid modes result
in a return -EINVAL. Such a situation should never occur in reality, but
it's good to define a default switch case for the sake of making the
intent of the code clear.

Cc: Kamel Bouhara <kamel.bouhara@bootlin.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Acked-by: David Lechner <david@lechnology.com>
Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/7af82d4e39610da11edce0ee370285fe1cb1eac8.1627990337.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-08-09 20:17:36 +01:00
William Breathitt Gray
728246e8f7 counter: 104-quad-8: Return error when invalid mode during ceiling_write 
The 104-QUAD-8 only has two count modes where a ceiling value makes
sense: Range Limit and Modulo-N. Outside of these two modes, setting a
ceiling value is an invalid operation -- so let's report it as such by
returning -EINVAL.

Fixes: fc06926226 ("counter: 104-quad-8: Add lock guards - generic interface")
Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/a2147f022829b66839a1db5530a7fada47856847.1627990337.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-08-09 20:17:36 +01:00
Jarkko Nikula
62f9eb7079 counter: intel-qep: Remove linux/bitops.h include 
0-DAY CI Kernel Test Service reported following iwyu warning:

drivers/counter/intel-qep.c:11:1: iwyu: warning: superfluous #include <linux/bitops.h>

Remove that include since we don't seem to use anything from it.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20210629111657.2655688-1-jarkko.nikula@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-07-13 19:07:10 +01:00
William Breathitt Gray
bc84957d31 counter: interrupt-cnt: Add const qualifier for actions_list array 
The struct counter_synapse actions_list member expects a const enum
counter_synapse_action array. This patch renames
interrupt_cnt_synapse_actionss to interrupt_cnt_synapse_actions and adds
a const qualifier to match actions_list.

Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20210610013642.149961-1-vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-06-13 17:00:18 +01:00
Jarkko Nikula
93466212b9 counter: intel-qep: Use to_pci_dev() helper 
Use to_pci_dev() helper instead of container_of(d, struct pci_dev, dev);

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20210611115558.796338-2-jarkko.nikula@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-06-13 17:00:17 +01:00
Jarkko Nikula
ac3bd9d6b1 counter: intel-qep: Mark PM callbacks with __maybe_unused 
Remove CONFIG_PM ifdef and mark PM callbacks with __maybe_unused.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20210611115558.796338-1-jarkko.nikula@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
 2021-06-13 17:00:17 +01:00