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Commit e690ae52 authored by Ed Blake's avatar Ed Blake Committed by Thierry Reding
Browse files

pwm: img: Add runtime PM 



Add runtime PM to disable the clocks when the h/w is not in use.

Signed-off-by: default avatarEd Blake <ed.blake@sondrel.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent a18afce5

drivers/pwm/pwm-img.c

+95 −37
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/of.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>

#include <linux/pwm.h>

#include <linux/regmap.h>

#include <linux/slab.h>
@@ -39,6 +40,8 @@ 
#define PERIP_PWM_PDM_CONTROL_CH_MASK		0x1

#define PERIP_PWM_PDM_CONTROL_CH_SHIFT(ch)	((ch) * 4)



#define IMG_PWM_PM_TIMEOUT			1000 /* ms */



/*

 * PWM period is specified with a timebase register,

 * in number of step periods. The PWM duty cycle is also
@@ -96,6 +99,7 @@ static int img_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 
	unsigned long mul, output_clk_hz, input_clk_hz;

	struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip);

	unsigned int max_timebase = pwm_chip->data->max_timebase;

	int ret;



	if (period_ns < pwm_chip->min_period_ns ||

	    period_ns > pwm_chip->max_period_ns) {
@@ -127,6 +131,10 @@ static int img_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 


	duty = DIV_ROUND_UP(timebase * duty_ns, period_ns);



	ret = pm_runtime_get_sync(chip->dev);

	if (ret < 0)

		return ret;



	val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);

	val &= ~(PWM_CTRL_CFG_DIV_MASK << PWM_CTRL_CFG_DIV_SHIFT(pwm->hwpwm));

	val |= (div & PWM_CTRL_CFG_DIV_MASK) <<
@@ -137,6 +145,9 @@ static int img_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 
	      (timebase << PWM_CH_CFG_TMBASE_SHIFT);

	img_pwm_writel(pwm_chip, PWM_CH_CFG(pwm->hwpwm), val);



	pm_runtime_mark_last_busy(chip->dev);

	pm_runtime_put_autosuspend(chip->dev);



	return 0;

}
@@ -144,6 +155,11 @@ static int img_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) 
{

	u32 val;

	struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip);

	int ret;



	ret = pm_runtime_get_sync(chip->dev);

	if (ret < 0)

		return ret;



	val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);

	val |= BIT(pwm->hwpwm);
@@ -164,6 +180,9 @@ static void img_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) 
	val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);

	val &= ~BIT(pwm->hwpwm);

	img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);



	pm_runtime_mark_last_busy(chip->dev);

	pm_runtime_put_autosuspend(chip->dev);

}



static const struct pwm_ops img_pwm_ops = {
@@ -186,6 +205,37 @@ static const struct of_device_id img_pwm_of_match[] = { 
};

MODULE_DEVICE_TABLE(of, img_pwm_of_match);



static int img_pwm_runtime_suspend(struct device *dev)

{

	struct img_pwm_chip *pwm_chip = dev_get_drvdata(dev);



	clk_disable_unprepare(pwm_chip->pwm_clk);

	clk_disable_unprepare(pwm_chip->sys_clk);



	return 0;

}



static int img_pwm_runtime_resume(struct device *dev)

{

	struct img_pwm_chip *pwm_chip = dev_get_drvdata(dev);

	int ret;



	ret = clk_prepare_enable(pwm_chip->sys_clk);

	if (ret < 0) {

		dev_err(dev, "could not prepare or enable sys clock\n");

		return ret;

	}



	ret = clk_prepare_enable(pwm_chip->pwm_clk);

	if (ret < 0) {

		dev_err(dev, "could not prepare or enable pwm clock\n");

		clk_disable_unprepare(pwm_chip->sys_clk);

		return ret;

	}



	return 0;

}



static int img_pwm_probe(struct platform_device *pdev)

{

	int ret;
@@ -228,23 +278,20 @@ static int img_pwm_probe(struct platform_device *pdev) 
		return PTR_ERR(pwm->pwm_clk);

	}



	ret = clk_prepare_enable(pwm->sys_clk);

	if (ret < 0) {

		dev_err(&pdev->dev, "could not prepare or enable sys clock\n");

		return ret;

	}



	ret = clk_prepare_enable(pwm->pwm_clk);

	if (ret < 0) {

		dev_err(&pdev->dev, "could not prepare or enable pwm clock\n");

		goto disable_sysclk;

	pm_runtime_set_autosuspend_delay(&pdev->dev, IMG_PWM_PM_TIMEOUT);

	pm_runtime_use_autosuspend(&pdev->dev);

	pm_runtime_enable(&pdev->dev);

	if (!pm_runtime_enabled(&pdev->dev)) {

		ret = img_pwm_runtime_resume(&pdev->dev);

		if (ret)

			goto err_pm_disable;

	}



	clk_rate = clk_get_rate(pwm->pwm_clk);

	if (!clk_rate) {

		dev_err(&pdev->dev, "pwm clock has no frequency\n");

		ret = -EINVAL;

		goto disable_pwmclk;

		goto err_suspend;

	}



	/* The maximum input clock divider is 512 */
@@ -264,16 +311,18 @@ static int img_pwm_probe(struct platform_device *pdev) 
	ret = pwmchip_add(&pwm->chip);

	if (ret < 0) {

		dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret);

		goto disable_pwmclk;

		goto err_suspend;

	}



	platform_set_drvdata(pdev, pwm);

	return 0;



disable_pwmclk:

	clk_disable_unprepare(pwm->pwm_clk);

disable_sysclk:

	clk_disable_unprepare(pwm->sys_clk);

err_suspend:

	if (!pm_runtime_enabled(&pdev->dev))

		img_pwm_runtime_suspend(&pdev->dev);

err_pm_disable:

	pm_runtime_disable(&pdev->dev);

	pm_runtime_dont_use_autosuspend(&pdev->dev);

	return ret;

}
@@ -282,6 +331,11 @@ static int img_pwm_remove(struct platform_device *pdev) 
	struct img_pwm_chip *pwm_chip = platform_get_drvdata(pdev);

	u32 val;

	unsigned int i;

	int ret;



	ret = pm_runtime_get_sync(&pdev->dev);

	if (ret < 0)

		return ret;



	for (i = 0; i < pwm_chip->chip.npwm; i++) {

		val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
@@ -289,8 +343,10 @@ static int img_pwm_remove(struct platform_device *pdev) 
		img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);

	}



	clk_disable_unprepare(pwm_chip->pwm_clk);

	clk_disable_unprepare(pwm_chip->sys_clk);

	pm_runtime_put(&pdev->dev);

	pm_runtime_disable(&pdev->dev);

	if (!pm_runtime_status_suspended(&pdev->dev))

		img_pwm_runtime_suspend(&pdev->dev);



	return pwmchip_remove(&pwm_chip->chip);

}
@@ -298,9 +354,14 @@ static int img_pwm_remove(struct platform_device *pdev) 
#ifdef CONFIG_PM_SLEEP

static int img_pwm_suspend(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct img_pwm_chip *pwm_chip = platform_get_drvdata(pdev);

	int i;

	struct img_pwm_chip *pwm_chip = dev_get_drvdata(dev);

	int i, ret;



	if (pm_runtime_status_suspended(dev)) {

		ret = img_pwm_runtime_resume(dev);

		if (ret)

			return ret;

	}



	for (i = 0; i < pwm_chip->chip.npwm; i++)

		pwm_chip->suspend_ch_cfg[i] = img_pwm_readl(pwm_chip,
@@ -308,31 +369,20 @@ static int img_pwm_suspend(struct device *dev) 


	pwm_chip->suspend_ctrl_cfg = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);



	clk_disable_unprepare(pwm_chip->pwm_clk);

	clk_disable_unprepare(pwm_chip->sys_clk);

	img_pwm_runtime_suspend(dev);



	return 0;

}



static int img_pwm_resume(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct img_pwm_chip *pwm_chip = platform_get_drvdata(pdev);

	struct img_pwm_chip *pwm_chip = dev_get_drvdata(dev);

	int ret;

	int i;



	ret = clk_prepare_enable(pwm_chip->sys_clk);

	if (ret < 0) {

		dev_err(&pdev->dev, "could not prepare or enable sys clock\n");

	ret = img_pwm_runtime_resume(dev);

	if (ret)

		return ret;

	}



	ret = clk_prepare_enable(pwm_chip->pwm_clk);

	if (ret < 0) {

		dev_err(&pdev->dev, "could not prepare or enable pwm clock\n");

		clk_disable_unprepare(pwm_chip->sys_clk);

		return ret;

	}



	for (i = 0; i < pwm_chip->chip.npwm; i++)

		img_pwm_writel(pwm_chip, PWM_CH_CFG(i),
@@ -348,11 +398,19 @@ static int img_pwm_resume(struct device *dev) 
					   PERIP_PWM_PDM_CONTROL_CH_SHIFT(i),

					   0);



	if (pm_runtime_status_suspended(dev))

		img_pwm_runtime_suspend(dev);



	return 0;

}

#endif /* CONFIG_PM */



SIMPLE_DEV_PM_OPS(img_pwm_pm_ops, img_pwm_suspend, img_pwm_resume);

static const struct dev_pm_ops img_pwm_pm_ops = {

	SET_RUNTIME_PM_OPS(img_pwm_runtime_suspend,

			   img_pwm_runtime_resume,

			   NULL)

	SET_SYSTEM_SLEEP_PM_OPS(img_pwm_suspend, img_pwm_resume)

};



static struct platform_driver img_pwm_driver = {

	.driver = {