kernel/linux.git/drivers/pwm, branch v4.14.217

pwm: lp3943: Dynamically allocate PWM chip base

2020-12-29T12:47:03+00:00

[ Upstream commit 1f0f1e80fdd3aa9631f6c22cda4f8550cfcfcc3e ] When there are other PWM controllers enabled along with pwm-lp3943, pwm-lp3942 is failing to probe with -EEXIST error. This is because other PWM controllers are probed first and assigned PWM base 0 and pwm-lp3943 is requesting for 0 again. In order to avoid this, assign the chip base with -1, so that it is dynamically allocated. Fixes: af66b3c0934e ("pwm: Add LP3943 PWM driver") Signed-off-by: Lokesh Vutla Reviewed-by: Uwe Kleine-König Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: zx: Add missing cleanup in error path

2020-12-29T12:47:03+00:00

[ Upstream commit 269effd03f6142df4c74814cfdd5f0b041b30bf9 ] zx_pwm_probe() called clk_prepare_enable() before; this must be undone in the error path. Fixes: 4836193c435c ("pwm: Add ZTE ZX PWM device driver") Signed-off-by: Uwe Kleine-König Acked-by: Shawn Guo Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: lpss: Add range limit check for the base_unit register value

2020-10-29T08:07:05+00:00

[ Upstream commit ef9f60daab309558c8bb3e086a9a11ee40bd6061 ] When the user requests a high enough period ns value, then the calculations in pwm_lpss_prepare() might result in a base_unit value of 0. But according to the data-sheet the way the PWM controller works is that each input clock-cycle the base_unit gets added to a N bit counter and that counter overflowing determines the PWM output frequency. Adding 0 to the counter is a no-op. The data-sheet even explicitly states that writing 0 to the base_unit bits will result in the PWM outputting a continuous 0 signal. When the user requestes a low enough period ns value, then the calculations in pwm_lpss_prepare() might result in a base_unit value which is bigger then base_unit_range - 1. Currently the codes for this deals with this by applying a mask: base_unit &= (base_unit_range - 1); But this means that we let the value overflow the range, we throw away the higher bits and store whatever value is left in the lower bits into the register leading to a random output frequency, rather then clamping the output frequency to the highest frequency which the hardware can do. This commit fixes both issues by clamping the base_unit value to be between 1 and (base_unit_range - 1). Fixes: 684309e5043e ("pwm: lpss: Avoid potential overflow of base_unit") Reviewed-by: Andy Shevchenko Acked-by: Thierry Reding Signed-off-by: Hans de Goede Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-5-hdegoede@redhat.com Signed-off-by: Sasha Levin

pwm: lpss: Fix off by one error in base_unit math in pwm_lpss_prepare()

2020-10-29T08:07:05+00:00

[ Upstream commit 181f4d2f44463fe09fe4df02e03095cb87151c29 ] According to the data-sheet the way the PWM controller works is that each input clock-cycle the base_unit gets added to a N bit counter and that counter overflowing determines the PWM output frequency. So assuming e.g. a 16 bit counter this means that if base_unit is set to 1, after 65535 input clock-cycles the counter has been increased from 0 to 65535 and it will overflow on the next cycle, so it will overflow after every 65536 clock cycles and thus the calculations done in pwm_lpss_prepare() should use 65536 and not 65535. This commit fixes this. Note this also aligns the calculations in pwm_lpss_prepare() with those in pwm_lpss_get_state(). Note this effectively reverts commit 684309e5043e ("pwm: lpss: Avoid potential overflow of base_unit"). The next patch in this series really fixes the potential overflow of the base_unit value. Fixes: 684309e5043e ("pwm: lpss: Avoid potential overflow of base_unit") Reviewed-by: Andy Shevchenko Acked-by: Uwe Kleine-König Acked-by: Thierry Reding Signed-off-by: Hans de Goede Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-4-hdegoede@redhat.com Signed-off-by: Sasha Levin

pwm: bcm-iproc: handle clk_get_rate() return

2020-08-21T07:48:21+00:00

[ Upstream commit 6ced5ff0be8e94871ba846dfbddf69d21363f3d7 ] Handle clk_get_rate() returning 0 to avoid possible division by zero. Fixes: daa5abc41c80 ("pwm: Add support for Broadcom iProc PWM controller") Signed-off-by: Rayagonda Kokatanur Signed-off-by: Scott Branden Reviewed-by: Ray Jui Reviewed-by: Uwe Kleine-König Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: bcm2835: Dynamically allocate base

2020-05-02T15:24:15+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

2020-05-02T15:24:15+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

2020-05-02T15:24:13+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: pca9685: Fix PWM/GPIO inter-operation

2020-04-24T06:00:55+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'

2020-02-28T15:36:05+00:00

[ Upstream commit 9871abffc81048e20f02e15d6aa4558a44ad53ea ] 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 Signed-off-by: Sasha Levin