linux-stable/drivers/pwm
Fabrice Gasnier 6534865953 pwm: stm32-lp: Add check in case requested period cannot be achieved
[ Upstream commit c91e3234c6 ]

LPTimer can use a 32KHz clock for counting. It depends on clock tree
configuration. In such a case, PWM output frequency range is limited.
Although unlikely, nothing prevents user from requesting a PWM frequency
above counting clock (32KHz for instance):
- This causes (prd - 1) = 0xffff to be written in ARR register later in
the apply() routine.
This results in badly configured PWM period (and also duty_cycle).
Add a check to report an error is such a case.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-11 18:21:17 +02:00
..
core.c pwm: Fix deadlock warning when removing PWM device 2019-06-15 11:54:10 +02:00
Kconfig
Makefile
pwm-ab8500.c
pwm-atmel-hlcdc.c
pwm-atmel-tcb.c
pwm-atmel.c
pwm-bcm-iproc.c
pwm-bcm-kona.c
pwm-bcm2835.c
pwm-berlin.c
pwm-brcmstb.c
pwm-clps711x.c
pwm-crc.c
pwm-cros-ec.c
pwm-ep93xx.c
pwm-fsl-ftm.c
pwm-hibvt.c
pwm-img.c
pwm-imx.c
pwm-jz4740.c
pwm-lp3943.c
pwm-lpc18xx-sct.c
pwm-lpc32xx.c
pwm-lpss-pci.c
pwm-lpss-platform.c
pwm-lpss.c
pwm-lpss.h
pwm-mediatek.c
pwm-meson.c
pwm-mtk-disp.c
pwm-mxs.c
pwm-omap-dmtimer.c
pwm-pca9685.c
pwm-puv3.c
pwm-pxa.c
pwm-rcar.c
pwm-renesas-tpu.c
pwm-rockchip.c
pwm-samsung.c
pwm-spear.c
pwm-sti.c
pwm-stm32-lp.c pwm: stm32-lp: Add check in case requested period cannot be achieved 2019-10-11 18:21:17 +02:00
pwm-stm32.c
pwm-stmpe.c
pwm-sun4i.c
pwm-tegra.c
pwm-tiecap.c
pwm-tiehrpwm.c
pwm-tipwmss.c
pwm-twl-led.c
pwm-twl.c
pwm-vt8500.c
pwm-zx.c
sysfs.c Revert "pwm: Set class for exported channels in sysfs" 2019-08-25 10:47:46 +02:00