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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>
This commit is contained in:
Jisheng Zhang 2015-11-25 17:41:25 +08:00 committed by Thierry Reding
parent 45c0ce847a
commit bbf0722c1c
1 changed files with 84 additions and 0 deletions
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84
drivers/pwm/pwm-berlin.c
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@ -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);