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pwm: img: Add runtime PM 

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

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
hifive-unleashed-5.1
Ed Blake 2017-10-02 10:51:48 +01:00 committed by Thierry Reding
parent a18afce522
commit e690ae5262
1 changed files with 95 additions and 37 deletions
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132
drivers/pwm/pwm-img.c
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@ -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 = {