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Commit cce4a833 authored by Fabrice Gasnier's avatar Fabrice Gasnier Committed by Thierry Reding
Browse files

pwm: stm32-lp: Add power management support 

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: default avatarFabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent f6c9b597

drivers/pwm/pwm-stm32-lp.c

+25 −0
Original line number Diff line number Diff line
@@ -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);