Commit bbf0722c authored by Jisheng Zhang's avatar Jisheng Zhang Committed by Thierry Reding
Browse files

pwm: berlin: Add suspend/resume support 



This patch adds suspend-to-RAM support to the Berlin PWM driver.

Signed-off-by: default avatarJisheng Zhang <jszhang@marvell.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent 45c0ce84

drivers/pwm/pwm-berlin.c

+84 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/pwm.h>

#include <linux/slab.h>



#define BERLIN_PWM_EN			0x0

#define  BERLIN_PWM_ENABLE		BIT(0)
@@ -27,6 +28,13 @@ 
#define BERLIN_PWM_TCNT			0xc

#define  BERLIN_PWM_MAX_TCNT		65535



struct berlin_pwm_channel {

	u32 enable;

	u32 ctrl;

	u32 duty;

	u32 tcnt;

};



struct berlin_pwm_chip {

	struct pwm_chip chip;

	struct clk *clk;
@@ -55,6 +63,25 @@ static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip, 
	writel_relaxed(value, chip->base + channel * 0x10 + offset);

}



static int berlin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)

{

	struct berlin_pwm_channel *channel;



	channel = kzalloc(sizeof(*channel), GFP_KERNEL);

	if (!channel)

		return -ENOMEM;



	return pwm_set_chip_data(pwm, channel);

}



static void berlin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)

{

	struct berlin_pwm_channel *channel = pwm_get_chip_data(pwm);



	pwm_set_chip_data(pwm, NULL);

	kfree(channel);

}



static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev,

			     int duty_ns, int period_ns)

{
@@ -137,6 +164,8 @@ static void berlin_pwm_disable(struct pwm_chip *chip, 
}



static const struct pwm_ops berlin_pwm_ops = {

	.request = berlin_pwm_request,

	.free = berlin_pwm_free,

	.config = berlin_pwm_config,

	.set_polarity = berlin_pwm_set_polarity,

	.enable = berlin_pwm_enable,
@@ -204,12 +233,67 @@ static int berlin_pwm_remove(struct platform_device *pdev) 
	return ret;

}



#ifdef CONFIG_PM_SLEEP

static int berlin_pwm_suspend(struct device *dev)

{

	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);

	unsigned int i;



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

		struct berlin_pwm_channel *channel;



		channel = pwm_get_chip_data(&pwm->chip.pwms[i]);

		if (!channel)

			continue;



		channel->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);

		channel->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);

		channel->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);

		channel->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);

	}



	clk_disable_unprepare(pwm->clk);



	return 0;

}



static int berlin_pwm_resume(struct device *dev)

{

	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);

	unsigned int i;

	int ret;



	ret = clk_prepare_enable(pwm->clk);

	if (ret)

		return ret;



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

		struct berlin_pwm_channel *channel;



		channel = pwm_get_chip_data(&pwm->chip.pwms[i]);

		if (!channel)

			continue;



		berlin_pwm_writel(pwm, i, channel->ctrl, BERLIN_PWM_CONTROL);

		berlin_pwm_writel(pwm, i, channel->duty, BERLIN_PWM_DUTY);

		berlin_pwm_writel(pwm, i, channel->tcnt, BERLIN_PWM_TCNT);

		berlin_pwm_writel(pwm, i, channel->enable, BERLIN_PWM_ENABLE);

	}



	return 0;

}

#endif



static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,

			 berlin_pwm_resume);



static struct platform_driver berlin_pwm_driver = {

	.probe = berlin_pwm_probe,

	.remove = berlin_pwm_remove,

	.driver = {

		.name = "berlin-pwm",

		.of_match_table = berlin_pwm_match,

		.pm = &berlin_pwm_pm_ops,

	},

};

module_platform_driver(berlin_pwm_driver);