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. Only perform a check here, and handle the pinctrl states. See [1]. [1] https://lkml.org/lkml/2019/2/5/770 Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx> --- Changes in v2: - Don't disable PWM channel: let the PWM user disable it. Refuse to suspend in case it's been left enabled. - Drop the ifdefs, use __maybe_unused instead. --- drivers/pwm/pwm-stm32-lp.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/drivers/pwm/pwm-stm32-lp.c b/drivers/pwm/pwm-stm32-lp.c index 0059b24c..2211a64 100644 --- a/drivers/pwm/pwm-stm32-lp.c +++ b/drivers/pwm/pwm-stm32-lp.c @@ -13,6 +13,7 @@ #include <linux/mfd/stm32-lptimer.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/pinctrl/consumer.h> #include <linux/platform_device.h> #include <linux/pwm.h> @@ -223,6 +224,29 @@ static int stm32_pwm_lp_remove(struct platform_device *pdev) return pwmchip_remove(&priv->chip); } +static int __maybe_unused stm32_pwm_lp_suspend(struct device *dev) +{ + struct stm32_pwm_lp *priv = dev_get_drvdata(dev); + struct pwm_state state; + + pwm_get_state(&priv->chip.pwms[0], &state); + if (state.enabled) { + dev_err(dev, "The consumer didn't stop us (%s)\n", + priv->chip.pwms[0].label); + return -EBUSY; + } + + return pinctrl_pm_select_sleep_state(dev); +} + +static int __maybe_unused stm32_pwm_lp_resume(struct device *dev) +{ + return pinctrl_pm_select_default_state(dev); +} + +static SIMPLE_DEV_PM_OPS(stm32_pwm_lp_pm_ops, stm32_pwm_lp_suspend, + stm32_pwm_lp_resume); + static const struct of_device_id stm32_pwm_lp_of_match[] = { { .compatible = "st,stm32-pwm-lp", }, {}, @@ -235,6 +259,7 @@ static struct platform_driver stm32_pwm_lp_driver = { .driver = { .name = "stm32-pwm-lp", .of_match_table = of_match_ptr(stm32_pwm_lp_of_match), + .pm = &stm32_pwm_lp_pm_ops, }, }; module_platform_driver(stm32_pwm_lp_driver); -- 2.7.4
