On 10/16/19 9:06 AM, Thierry Reding wrote: > On Fri, Oct 04, 2019 at 02:53:53PM +0200, Fabrice Gasnier wrote: >> Add suspend/resume PM sleep ops. When going to low power, enforce the PWM >> channel isn't active. Let the PWM consumers disable it during their own >> suspend sequence, see [1]. So, perform a check here, and handle the >> pinctrl states. Also restore the break inputs upon resume, as registers >> content may be lost when going to low power mode. >> >> [1] https://lkml.org/lkml/2019/2/5/770 >> >> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx> >> --- >> Changes in v2: >> Follow Uwe suggestions/remarks: >> - Add a precursor patch to ease reviewing >> - Use registers read instead of pwm_get_state >> - Add a comment to mention registers content may be lost in low power mode >> --- >> drivers/pwm/pwm-stm32.c | 38 ++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 38 insertions(+) > > Applied, thanks. I made two minor changes, though, see below. > >> >> diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c >> index cf8658c..546b661 100644 >> --- a/drivers/pwm/pwm-stm32.c >> +++ b/drivers/pwm/pwm-stm32.c >> @@ -12,6 +12,7 @@ >> #include <linux/mfd/stm32-timers.h> >> #include <linux/module.h> >> #include <linux/of.h> >> +#include <linux/pinctrl/consumer.h> >> #include <linux/platform_device.h> >> #include <linux/pwm.h> >> >> @@ -655,6 +656,42 @@ static int stm32_pwm_remove(struct platform_device *pdev) >> return 0; >> } >> >> +static int __maybe_unused stm32_pwm_suspend(struct device *dev) >> +{ >> + struct stm32_pwm *priv = dev_get_drvdata(dev); >> + unsigned int ch; > > I renamed this to just "i", which is more idiomatic for loop variables. > The function is small enough not to need to differentiate between loop > variables. > >> + u32 ccer, mask; >> + >> + /* Look for active channels */ >> + ccer = active_channels(priv); >> + >> + for (ch = 0; ch < priv->chip.npwm; ch++) { >> + mask = TIM_CCER_CC1E << (ch * 4); >> + if (ccer & mask) { >> + dev_err(dev, "The consumer didn't stop us (%s)\n", >> + priv->chip.pwms[ch].label); > > Changed this to: > > "PWM %u still in use by consumer %s\n", i, priv->chip.pwms[i].label > > I think that might help clarify which PWM is still enabled in case the > consumers don't set a label. Hi Thierry, Many thanks for all the improvements on this series! Best Regards, Fabrice > > Thierry > >> + return -EBUSY; >> + } >> + } >> + >> + return pinctrl_pm_select_sleep_state(dev); >> +} >> + >> +static int __maybe_unused stm32_pwm_resume(struct device *dev) >> +{ >> + struct stm32_pwm *priv = dev_get_drvdata(dev); >> + int ret; >> + >> + ret = pinctrl_pm_select_default_state(dev); >> + if (ret) >> + return ret; >> + >> + /* restore breakinput registers that may have been lost in low power */ >> + return stm32_pwm_apply_breakinputs(priv); >> +} >> + >> +static SIMPLE_DEV_PM_OPS(stm32_pwm_pm_ops, stm32_pwm_suspend, stm32_pwm_resume); >> + >> static const struct of_device_id stm32_pwm_of_match[] = { >> { .compatible = "st,stm32-pwm", }, >> { /* end node */ }, >> @@ -667,6 +704,7 @@ static struct platform_driver stm32_pwm_driver = { >> .driver = { >> .name = "stm32-pwm", >> .of_match_table = stm32_pwm_of_match, >> + .pm = &stm32_pwm_pm_ops, >> }, >> }; >> module_platform_driver(stm32_pwm_driver); >> -- >> 2.7.4 >>
