linux-stable.git/include/linux/pwm.h, branch v5.16.3 Linux kernel stable tree pwm: Make it explicit that pwm_apply_state() might sleep 2021-11-05T10:51:41+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2021-09-09T09:48:49+00:00 4ad91a227817ae48f931595d1101fc7100073ce9 At least some implementations sleep. So mark pwm_apply_state() with a might_sleep() to make callers aware. In the worst case this uncovers a valid atomic user, then we revert this patch and at least gained some more knowledge and then can work on a concept similar to gpio_get_value/gpio_get_value_cansleep. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
At least some implementations sleep. So mark pwm_apply_state() with a
might_sleep() to make callers aware. In the worst case this uncovers a
valid atomic user, then we revert this patch and at least gained some more
knowledge and then can work on a concept similar to
gpio_get_value/gpio_get_value_cansleep.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: Add might_sleep() annotations for !CONFIG_PWM API functions 2021-11-05T10:51:40+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2021-09-09T09:48:48+00:00 27d9a4d69433af1827a764fe235866d5d5501fdb The normal implementations of these functions make use of mutexes. To make it obvious that these functions might sleep also add annotations to the dummy implementations in the !CONFIG_PWM case. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
The normal implementations of these functions make use of mutexes. To
make it obvious that these functions might sleep also add annotations to
the dummy implementations in the !CONFIG_PWM case.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: Make pwmchip_remove() return void 2021-09-02T19:38:56+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2021-07-07T16:28:35+00:00 8083f58d08fd52f547c0a62c0f4e448e15e6726b Since some time pwmchip_remove() always returns 0 so the return value isn't usefull. Now that all callers are converted to ignore its value the function can be changed to return void. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
Since some time pwmchip_remove() always returns 0 so the return value
isn't usefull. Now that all callers are converted to ignore its value
the function can be changed to return void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: core: Remove unused devm_pwm_put() 2021-06-30T17:12:19+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2021-06-07T12:24:57+00:00 c333b936c1530e76eba4e81091874d1217046131 There are no users and seems no will come of the devm_pwm_put(). Remove the function. While at it, slightly update documentation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
There are no users and seems no will come of the devm_pwm_put().
Remove the function.

While at it, slightly update documentation.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: Add a device-managed function to add PWM chips 2021-06-28T11:17:48+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2021-04-07T08:01:54+00:00 bcda91bf86c1ff7647df85029d69f2aed80f210e This potentially simplifies low-level PWM drivers. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
This potentially simplifies low-level PWM drivers.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: core: Support new usage_power setting in PWM state 2021-06-04T09:43:52+00:00 Clemens Gruber clemens.gruber@pqgruber.com 2021-05-07T13:18:42+00:00 9e40ee18a1dc1623a5368d6232aaed52fd29dada If usage_power is set, the PWM driver is only required to maintain the power output but has more freedom regarding signal form. If supported, the signal can be optimized, for example to improve EMI by phase shifting individual channels. Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
If usage_power is set, the PWM driver is only required to maintain
the power output but has more freedom regarding signal form.

If supported, the signal can be optimized, for example to
improve EMI by phase shifting individual channels.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: Clarify which state pwm_get_state() returns 2021-04-09T12:17:03+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2021-04-06T07:30:36+00:00 1a7a6e8072ea0e4582de2da63a9088841fde798e Given that lowlevel drivers usually cannot implement exactly what a consumer requests with pwm_apply_state() there is some rounding involved. pwm_get_state() returns the setting that was requested most recently by the consumer (opposed to what was actually implemented in hardware in reply to the last request). Clarify this in the function kerneldoc. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
Given that lowlevel drivers usually cannot implement exactly what a
consumer requests with pwm_apply_state() there is some rounding
involved.

pwm_get_state() returns the setting that was requested most recently by
the consumer (opposed to what was actually implemented in hardware in
reply to the last request). Clarify this in the function kerneldoc.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: Drop function pwmchip_add_with_polarity() 2021-03-22T11:31:32+00:00 Uwe Kleine-König uwe@kleine-koenig.org 2020-12-07T13:45:56+00:00 9666cec380d60808eb86d3be4caf84faeebe3081 pwmchip_add() only calls pwmchip_add_with_polarity() and nothing else. All other users of pwmchip_add_with_polarity() are gone. So drop pwmchip_add_with_polarity() and move the code instead to pwmchip_add(). The initial assignment to pwm->state.polarity is dropped. In every correct usage of the PWM API this value is overwritten later anyhow. Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
pwmchip_add() only calls pwmchip_add_with_polarity() and nothing else. All
other users of pwmchip_add_with_polarity() are gone. So drop
pwmchip_add_with_polarity() and move the code instead to pwmchip_add().

The initial assignment to pwm->state.polarity is dropped. In every correct
usage of the PWM API this value is overwritten later anyhow.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: Remove unused function pwmchip_add_inversed() 2020-12-17T13:19:01+00:00 Uwe Kleine-König uwe@kleine-koenig.org 2020-12-05T16:19:24+00:00 3df23a316c4a5d1764b034c71c29d67a17d5299f This is only defined with CONFIG_PWM unset and was introduced together with pwmchip_add_with_polarity() (which is only defined with CONFIG_PWM enabled). I guess the series that introduced pwmchip_add_with_polarity() had a different concept in earlier revisions and the !CONFIG_PWM part was just not updated accordingly. Given that there is no implementation for pwmchip_add_with_polarity() without CONFIG_PWM, just drop pwmchip_add_inversed() instead of renaming it to pwmchip_add_with_polarity(). Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> Acked-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
This is only defined with CONFIG_PWM unset and was introduced together
with pwmchip_add_with_polarity() (which is only defined with CONFIG_PWM
enabled). I guess the series that introduced pwmchip_add_with_polarity()
had a different concept in earlier revisions and the !CONFIG_PWM part
was just not updated accordingly.

Given that there is no implementation for pwmchip_add_with_polarity()
without CONFIG_PWM, just drop pwmchip_add_inversed() instead of renaming
it to pwmchip_add_with_polarity().

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: Convert period and duty cycle to u64 2020-06-17T18:42:11+00:00 Guru Das Srinagesh gurus@codeaurora.org 2020-06-02T22:31:16+00:00 a9d887dc1c60ed67f2271d66560cdcf864c4a578 Because period and duty cycle are defined as ints with units of nanoseconds, the maximum time duration that can be set is limited to ~2.147 seconds. Change their definitions to u64 in the structs of the PWM framework so that higher durations may be set. Also use the right format specifiers in debug prints in both core.c, pwm-stm32-lp.c as well as video/fbdev/ssd1307fb.c. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
Because period and duty cycle are defined as ints with units of
nanoseconds, the maximum time duration that can be set is limited to
~2.147 seconds. Change their definitions to u64 in the structs of the
PWM framework so that higher durations may be set.

Also use the right format specifiers in debug prints in both core.c,
pwm-stm32-lp.c as well as video/fbdev/ssd1307fb.c.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>