linux-stable.git/include/linux/pwm.h, branch v6.9.2

pwm: Provide pwmchip_alloc() function and a devm variant of it

2024-02-15T11:59:15+00:00

This function allocates a struct pwm_chip and driver data. Compared to
the status quo the split into pwm_chip and driver data is new, otherwise
it doesn't change anything relevant (yet).

The intention is that after all drivers are switched to use this
allocation function, its possible to add a struct device to struct
pwm_chip to properly track the latter's lifetime without touching all
drivers again. Proper lifetime tracking is a necessary precondition to
introduce character device support for PWMs (that implements atomic
setting and doesn't suffer from the sysfs overhead of the /sys/class/pwm
userspace support).

The new function pwmchip_priv() (obviously?) only works for chips
allocated with pwmchip_alloc().

Link: https://lore.kernel.org/r/9577d6053a5a52536057dc8654ff567181c2da82.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König

pwm: Provide wrappers for storing and getting driver private data

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

These functions are useful to store and query driver private data
depending on the pwm_chip. After struct pwm_chip got its own struct
device, this can make use of dev_get_drvdata() and dev_set_drvdata() on
that device. These functions are required already now to convert
drivers to pwmchip_alloc() which must happen before changing
pwm_chip::dev.

Reviewed-by: AngeloGioacchino Del Regno 
Link: https://lore.kernel.org/r/67514cdf29d29bd8b4ad8d44fac87f6ae6dca1e5.1707900770.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: Drop useless member .of_pwm_n_cells of struct pwm_chip

2024-02-15T11:28:01+00:00

Apart from the two of_xlate implementations this member is write-only.
In the of_xlate functions of_pwm_xlate_with_flags() and
of_pwm_single_xlate() it's more sensible to check for args->args_count
because this is what is actually used in the device tree.

Acked-by: Douglas Anderson 
Link: https://lore.kernel.org/r/53d8c545aa8f79a920358be9e72e382b3981bdc4.1704835845.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König

pwm: linux/pwm.h: fix Excess kernel-doc description warning

2024-01-05T08:33:16+00:00

Remove the @pwm: line to prevent the kernel-doc warning:

include/linux/pwm.h:87: warning: Excess struct member 'pwm' description in 'pwm_device'

Signed-off-by: Randy Dunlap 
Cc: Thierry Reding 
Cc: Uwe Kleine-König 
Cc:  
Fixes: f3e25e68ceb2 ("pwm: Drop unused member "pwm" from struct pwm_device")
Reviewed-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding

pwm: Add pwm_apply_state() compatibility stub

2024-01-05T08:33:10+00:00

In order to make the transition to the new pwm_apply_might_sleep() a bit
smoother, add a compatibility stub. This will prevent new calls to the
old function introduced via other subsystems from breaking builds. Once
the next merge window has closed we can take another stab at removing
the stub.

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

pwm: Drop two unused API functions

2023-12-20T16:01:43+00:00

These functions are unused. Also I think there is no valid use case
where these are correct to be called. So drop them.

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

pwm: Make it possible to apply PWM changes in atomic context

2023-12-20T15:07:06+00:00

Some PWM devices require sleeping, for example if the pwm device is
connected over I2C. However, many PWM devices could be used from atomic
context, e.g. memory mapped PWM. This is useful for, for example, the
pwm-ir-tx driver which requires precise timing. Sleeping causes havoc
with the generated IR signal.

Since not all PWM devices can support atomic context, we also add a
pwm_might_sleep() function to check if is not supported.

Signed-off-by: Sean Young 
Reviewed-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding

pwm: Replace ENOTSUPP with EOPNOTSUPP

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

According to Documentation/dev-tools/checkpatch.rst ENOTSUPP is
not recommended and EOPNOTSUPP should be used instead.

Signed-off-by: Sean Young 
Acked-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding

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