linux-stable.git/drivers/pwm, branch linux-5.6.y

pwm: bcm2835: Dynamically allocate base

2020-04-29T14:34:33+00:00

[ Upstream commit 2c25b07e5ec119cab609e41407a1fb3fa61442f5 ]

The newer 2711 and 7211 chips have two PWM controllers and failure to
dynamically allocate the PWM base would prevent the second PWM
controller instance being probed for succeeding with an -EEXIST error
from alloc_pwms().

Fixes: e5a06dc5ac1f ("pwm: Add BCM2835 PWM driver")
Signed-off-by: Florian Fainelli 
Acked-by: Uwe Kleine-König 
Reviewed-by: Nicolas Saenz Julienne 
Signed-off-by: Thierry Reding 
Signed-off-by: Sasha Levin

pwm: renesas-tpu: Fix late Runtime PM enablement

2020-04-29T14:34:33+00:00

[ Upstream commit d5a3c7a4536e1329a758e14340efd0e65252bd3d ]

Runtime PM should be enabled before calling pwmchip_add(), as PWM users
can appear immediately after the PWM chip has been added.
Likewise, Runtime PM should always be disabled after the removal of the
PWM chip, even if the latter failed.

Fixes: 99b82abb0a35b073 ("pwm: Add Renesas TPU PWM driver")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Thierry Reding 
Signed-off-by: Sasha Levin

pwm: rcar: Fix late Runtime PM enablement

2020-04-29T14:34:24+00:00

[ Upstream commit 1451a3eed24b5fd6a604683f0b6995e0e7e16c79 ]

Runtime PM should be enabled before calling pwmchip_add(), as PWM users
can appear immediately after the PWM chip has been added.
Likewise, Runtime PM should be disabled after the removal of the PWM
chip.

Fixes: ed6c1476bf7f16d5 ("pwm: Add support for R-Car PWM Timer")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Uwe Kleine-König 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Thierry Reding 
Signed-off-by: Sasha Levin

pwm: imx27: Fix clock handling in pwm_imx27_apply()

2020-04-29T14:34:23+00:00

[ Upstream commit 15d4dbd601591858611184f9ddeb5bf21569159c ]

pwm_imx27_apply() enables the clocks if the previous PWM state was
disabled. Given that the clocks are supposed to be left on iff the PWM
is running, the decision to disable the clocks at the end of the
function must not depend on the previous state.

Without this fix the enable count of the two affected clocks increases
by one whenever ->apply() changes from one disabled state to another.

Fixes: bd88d319abe9 ("pwm: imx27: Unconditionally write state to hardware")
Signed-off-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding 
Signed-off-by: Sasha Levin

pwm: pca9685: Fix PWM/GPIO inter-operation

2020-04-21T07:08:01+00:00

commit 9cc5f232a4b6a0ef6e9b57876d61b88f61bdd7c2 upstream.

This driver allows pwms to be requested as gpios via gpiolib. Obviously,
it should not be allowed to request a GPIO when its corresponding PWM is
already requested (and vice versa). So it requires some exclusion code.

Given that the PWMm and GPIO cores are not synchronized with respect to
each other, this exclusion code will also require proper
synchronization.

Such a mechanism was in place, but was inadvertently removed by Uwe's
clean-up in commit e926b12c611c ("pwm: Clear chip_data in pwm_put()").

Upon revisiting the synchronization mechanism, we found that
theoretically, it could allow two threads to successfully request
conflicting PWMs/GPIOs.

Replace with a bitmap which tracks PWMs in-use, plus a mutex. As long as
PWM and GPIO's respective request/free functions modify the in-use
bitmap while holding the mutex, proper synchronization will be
guaranteed.

Reported-by: YueHaibing 
Fixes: e926b12c611c ("pwm: Clear chip_data in pwm_put()")
Cc: Mika Westerberg 
Cc: Uwe Kleine-König 
Cc: YueHaibing 
Link: https://lkml.org/lkml/2019/5/31/963
Signed-off-by: Sven Van Asbroeck 
Reviewed-by: Mika Westerberg 
[cg: Tested on an i.MX6Q board with two NXP PCA9685 chips]
Tested-by: Clemens Gruber 
Reviewed-by: Sven Van Asbroeck  # cg's rebase
Link: https://lore.kernel.org/lkml/20200330160238.GD2817345@ulmo/
Signed-off-by: Thierry Reding 
Signed-off-by: Greg Kroah-Hartman

pwm: Remove set but not set variable 'pwm'

2020-01-20T14:40:49+00:00

Fixes gcc '-Wunused-but-set-variable' warning:

	drivers/pwm/pwm-pca9685.c: In function ‘pca9685_pwm_gpio_free’:
	drivers/pwm/pwm-pca9685.c:162:21: warning: variable ‘pwm’ set but not used [-Wunused-but-set-variable]

It is never used, and so can be removed. In that case, hold and release
the lock 'pca->lock' can be removed since nothing will be done between
them.

Fixes: e926b12c611c ("pwm: Clear chip_data in pwm_put()")
Signed-off-by: yu kuai 
Acked-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding

pwm: sun4i: Initialize variables before use

2020-01-20T14:22:37+00:00

GCC can't always determine that the duty, period and prescaler values
are initialized when returning from sun4i_pwm_calculate(), so help out a
little by initializing them to 0.

Signed-off-by: Thierry Reding

pwm: stm32: Remove automatic output enable

2020-01-20T12:47:36+00:00

Don't use AOE (automatic output enable) by default. In case of break
events, PWM is automatically re-enabled on next PWM cycle otherwise.

Signed-off-by: Fabrice Gasnier 
Signed-off-by: Thierry Reding

pwm: sun4i: Narrow scope of local variable

2020-01-20T12:22:42+00:00

The variable pval is only used in a single block in the function
sun4i_pwm_calculate(). So declare it in a more local scope to simplify
the function for humans and compilers.

While at it also simplify assignment to pval.

While the diffstat for this patch is negative for this patch I still
thing the advantage of having a narrower scope is beneficial.

In my compiler / .config setup (gcc 8.2.1, arm/imx_v6_v7_defconfig +
COMPILE_TEST + PWM_SUN4I) this change doesn't result in any binary
changes.

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

pwm: bcm2835: Allow building for ARCH_BRCMSTB

2020-01-20T12:21:44+00:00

BCM7211 is supported using ARCH_BRCMSTB and uses this PWM controller
driver, make it possible to build it.

Signed-off-by: Florian Fainelli 
Acked-by: Uwe Kleine-König 
Signed-off-by: Thierry Reding