linux-stable.git/drivers/pwm/sysfs.c, branch master

pwm: Move contents of sysfs.c into core.c

2024-04-26T19:29:17+00:00

With the upcoming restructuring having all in a single file simplifies
things a bit. The relevant and somewhat visible changes are:

 - Some dropped prototypes from include/linux/pwm.h that were only
   necessary that core.c has a declaration of the symbols defined in
   sysfs.c. The respective functions are static now.

 - The pwm class now also exists if CONFIG_SYSFS isn't enabled. Having
   CONFIG_SYSFS is not very relevant today, but even without it the
   class and device stuff still provides lifetime tracking.

 - Both files had an initcall, these are merged into a single one now.
   Instead of a big #ifdef block for CONFIG_DEBUG_FS, a single
   if (IS_ENABLED(CONFIG_DEBUG_FS)) is used now. This increases compile
   coverage a bit and is a tad nicer on the eyes.

Link: https://lore.kernel.org/r/9e2d39a5280d7dda5bfc6682a8aef510148635b2.1710670958.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König

pwm: Give some sysfs related variables and functions better names

2024-04-26T19:29:17+00:00

The code handling the sysfs API uses "child" and "parent" to refer to
the devices corresponding to a struct pwm or a struct pwm_chip
respectively.

Other parts of the pwm core use "parent" to refer to the parent device of
a struct pwm_chip.

So rename "child" to "pwm_dev" and "parent" to "pwmchip_dev" which
better explains the semantic. Also two functions are changed to match
the new names:

        child_to_pwm_export() -> pwmexport_from_dev()
        child_to_pwm_device() -> pwm_from_dev()

(which have the additional advantage to start with "pwm" which gives the
right scope). Additionally introduce a wrapper for dev_get_drvdata() to
convert a pwmchip_dev to the respective pwm_chip.

Link: https://lore.kernel.org/r/9cc05aceeae2f06ecb850bccb15ba821e768c183.1710670958.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König

pwm: Provide an inline function to get the parent device of a given chip

2024-02-15T11:37:29+00:00

Currently a pwm_chip stores in its struct device *dev member a pointer
to the parent device. Preparing a change that embeds a full struct
device in struct pwm_chip, this accessor function should be used in all
drivers directly accessing chip->dev now. This way struct pwm_chip and
this new function can be changed without having to touch all drivers in
the same change set.

Make use of this function in the framework's core sources.

Reviewed-by: Greg Kroah-Hartman 
Link: https://lore.kernel.org/r/cc30090d2f9762bed9854a55612144bccc910781.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König

pwm: Rename pwm_apply_state() to pwm_apply_might_sleep()

2023-12-20T15:07:04+00:00

In order to introduce a pwm api which can be used from atomic context,
we will need two functions for applying pwm changes:

	int pwm_apply_might_sleep(struct pwm *, struct pwm_state *);
	int pwm_apply_atomic(struct pwm *, struct pwm_state *);

This commit just deals with renaming pwm_apply_state(), a following
commit will introduce the pwm_apply_atomic() function.

Acked-by: Uwe Kleine-König 
Acked-by: Guenter Roeck 
Acked-by: Mark Brown 
Acked-by: Dmitry Torokhov  # for input
Acked-by: Hans de Goede 
Acked-by: Jani Nikula 
Acked-by: Lee Jones 
Signed-off-by: Sean Young 
Signed-off-by: Thierry Reding

pwm: Replace PWM chip unique base by unique ID

2023-12-20T15:04:12+00:00

Traditionally each PWM device had a unique ID stored in the "pwm" member
of struct pwm_device. However this number was hardly used and dropped
in the previous commit. To identify a certain PWM you're supposed to use
the chip's ID and the hwpwm of the PWM device now.

With the PWM chip base gone PWM chips can get their IDs better and
simpler using an idr.

This is expected to change the numbering of PWM chips, but nothing
should rely on the numbering anyhow.

Other than that the side effects are:

 - The PWM chip IDs are smaller and in most cases consecutive.
 - The ordering in /sys/kernel/debug/pwm is ordered by ascending PWM
   chip ID.

Signed-off-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding

pwm: sysfs: Do not apply state to already disabled PWMs

2023-06-23T13:42:58+00:00

If the PWM is exported but not enabled, do not call pwm_class_apply_state().
First of all, in this case, period may still be unconfigured and this would
make pwm_class_apply_state() return -EINVAL, and then suspend would fail.
Second, it makes little sense to apply state onto PWM that is not enabled
before suspend.

Failing case:
"
$ echo 1 > /sys/class/pwm/pwmchip4/export
$ echo mem > /sys/power/state
...
pwm pwmchip4: PM: dpm_run_callback(): pwm_class_suspend+0x1/0xa8 returns -22
pwm pwmchip4: PM: failed to suspend: error -22
PM: Some devices failed to suspend, or early wake event detected
"

Working case:
"
$ echo 1 > /sys/class/pwm/pwmchip4/export
$ echo 100 > /sys/class/pwm/pwmchip4/pwm1/period
$ echo 10 > /sys/class/pwm/pwmchip4/pwm1/duty_cycle
$ echo mem > /sys/power/state
...
"

Do not call pwm_class_apply_state() in case the PWM is disabled
to fix this issue.

Fixes: 7fd4edc57bbae ("pwm: sysfs: Add suspend/resume support")
Signed-off-by: Marek Vasut 
Fixes: ef2bf4997f7d ("pwm: Improve args checking in pwm_apply_state()")
Reviewed-by: Brian Norris 
Reviewed-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding

drivers: remove struct module * setting from struct class

2023-03-17T14:16:27+00:00

There is no need to manually set the owner of a struct class, as the
registering function does it automatically, so remove all of the
explicit settings from various drivers that did so as it is unneeded.

This allows us to remove this pointer entirely from this structure going
forward.

Cc: "Rafael J. Wysocki" 
Link: https://lore.kernel.org/r/20230313181843.1207845-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

pwm: sysfs: Replace sprintf() with sysfs_emit()

2022-09-28T15:52:02+00:00

While the uses in this code are unproblematic, it's generally safer for
sysfs outputs to use the new sysfs_emit() helper instead of raw calls to
sprintf() and friends. This also has the benefit of annotating the uses,
which makes them easier to audit and potentially use them to generate
sysfs documentation from them.

This patch replaces existing sprintf() calls straightforwardly with the
new helper.

Signed-off-by: Andy Shevchenko 
Reviewed-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding

pwm: sysfs: Switch to DEFINE_SIMPLE_DEV_PM_OPS() and pm_sleep_ptr()

2022-09-28T12:07:53+00:00

Using these newer macros allows the compiler to remove the unused
structure and functions when !CONFIG_PM_SLEEP + removes the need to
mark pm functions __maybe_unused.

Signed-off-by: Andy Shevchenko 
Reviewed-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding

pwm: Allow store 64-bit duty cycle from sysfs interface

2020-09-24T07:18:14+00:00

PWM core was converted to u64 by the commit a9d887dc1c60 ("pwm: Convert
period and duty cycle to u64") but did not change the duty_cycle_store()
so it will error out if trying to pass a numeric string bigger than
2^32-1.

Fix this by using u64 and kstrtou64() in duty_cycle_store().

Signed-off-by: Jarkko Nikula 
Acked-by: Guru Das Srinagesh 
Acked-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding