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	pwm: berlin: Add suspend/resume support
This patch adds suspend-to-RAM support to the Berlin PWM driver. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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					 1 changed files with 84 additions and 0 deletions
				
			
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			@ -16,6 +16,7 @@
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pwm.h>
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#include <linux/slab.h>
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#define BERLIN_PWM_EN			0x0
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#define  BERLIN_PWM_ENABLE		BIT(0)
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			@ -27,6 +28,13 @@
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#define BERLIN_PWM_TCNT			0xc
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#define  BERLIN_PWM_MAX_TCNT		65535
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struct berlin_pwm_channel {
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	u32 enable;
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	u32 ctrl;
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	u32 duty;
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	u32 tcnt;
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};
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struct berlin_pwm_chip {
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	struct pwm_chip chip;
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	struct clk *clk;
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			@ -55,6 +63,25 @@ static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip,
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	writel_relaxed(value, chip->base + channel * 0x10 + offset);
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}
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static int berlin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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	struct berlin_pwm_channel *channel;
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	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
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	if (!channel)
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		return -ENOMEM;
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	return pwm_set_chip_data(pwm, channel);
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}
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static void berlin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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	struct berlin_pwm_channel *channel = pwm_get_chip_data(pwm);
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	pwm_set_chip_data(pwm, NULL);
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	kfree(channel);
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}
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static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev,
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			     int duty_ns, int period_ns)
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{
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			@ -137,6 +164,8 @@ static void berlin_pwm_disable(struct pwm_chip *chip,
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}
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static const struct pwm_ops berlin_pwm_ops = {
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	.request = berlin_pwm_request,
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	.free = berlin_pwm_free,
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	.config = berlin_pwm_config,
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	.set_polarity = berlin_pwm_set_polarity,
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	.enable = berlin_pwm_enable,
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			@ -204,12 +233,67 @@ static int berlin_pwm_remove(struct platform_device *pdev)
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	return ret;
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}
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#ifdef CONFIG_PM_SLEEP
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static int berlin_pwm_suspend(struct device *dev)
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{
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	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
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	unsigned int i;
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	for (i = 0; i < pwm->chip.npwm; i++) {
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		struct berlin_pwm_channel *channel;
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		channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
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		if (!channel)
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			continue;
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		channel->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);
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		channel->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);
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		channel->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);
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		channel->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);
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	}
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	clk_disable_unprepare(pwm->clk);
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	return 0;
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}
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static int berlin_pwm_resume(struct device *dev)
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{
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	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
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	unsigned int i;
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	int ret;
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	ret = clk_prepare_enable(pwm->clk);
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	if (ret)
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		return ret;
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	for (i = 0; i < pwm->chip.npwm; i++) {
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		struct berlin_pwm_channel *channel;
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		channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
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		if (!channel)
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			continue;
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		berlin_pwm_writel(pwm, i, channel->ctrl, BERLIN_PWM_CONTROL);
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		berlin_pwm_writel(pwm, i, channel->duty, BERLIN_PWM_DUTY);
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		berlin_pwm_writel(pwm, i, channel->tcnt, BERLIN_PWM_TCNT);
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		berlin_pwm_writel(pwm, i, channel->enable, BERLIN_PWM_ENABLE);
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	}
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	return 0;
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}
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#endif
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static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
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			 berlin_pwm_resume);
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static struct platform_driver berlin_pwm_driver = {
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	.probe = berlin_pwm_probe,
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	.remove = berlin_pwm_remove,
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	.driver = {
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		.name = "berlin-pwm",
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		.of_match_table = berlin_pwm_match,
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		.pm = &berlin_pwm_pm_ops,
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	},
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};
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module_platform_driver(berlin_pwm_driver);
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