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pwm: img: Add suspend / resume handling 

The power may be disabled during suspend, so implement suspend and
resume callbacks to save and restore register state.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
[thierry.reding@gmail.com: guard using PM_SLEEP instead of PM]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Ed Blake 2017-10-02 10:51:47 +01:00 committed by Thierry Reding
parent 2bd6bf03f4
commit a18afce522
1 changed files with 65 additions and 1 deletions
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66
drivers/pwm/pwm-img.c
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@ -52,6 +52,8 @@
*/ */
#define MIN_TMBASE_STEPS 16 #define MIN_TMBASE_STEPS 16
#define IMG_PWM_NPWM 4
struct img_pwm_soc_data { struct img_pwm_soc_data {
u32 max_timebase; u32 max_timebase;
}; };
@ -66,6 +68,8 @@ struct img_pwm_chip {
int max_period_ns; int max_period_ns;
int min_period_ns; int min_period_ns;
const struct img_pwm_soc_data *data; const struct img_pwm_soc_data *data;
u32 suspend_ctrl_cfg;
u32 suspend_ch_cfg[IMG_PWM_NPWM];
}; };
static inline struct img_pwm_chip *to_img_pwm_chip(struct pwm_chip *chip) static inline struct img_pwm_chip *to_img_pwm_chip(struct pwm_chip *chip)
@ -255,7 +259,7 @@ static int img_pwm_probe(struct platform_device *pdev)
pwm->chip.dev = &pdev->dev; pwm->chip.dev = &pdev->dev;
pwm->chip.ops = &img_pwm_ops; pwm->chip.ops = &img_pwm_ops;
pwm->chip.base = -1; pwm->chip.base = -1;
pwm->chip.npwm = 4; pwm->chip.npwm = IMG_PWM_NPWM;
ret = pwmchip_add(&pwm->chip); ret = pwmchip_add(&pwm->chip);
if (ret < 0) { if (ret < 0) {
@ -291,9 +295,69 @@ static int img_pwm_remove(struct platform_device *pdev)
return pwmchip_remove(&pwm_chip->chip); return pwmchip_remove(&pwm_chip->chip);
} }
#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;
for (i = 0; i < pwm_chip->chip.npwm; i++)
pwm_chip->suspend_ch_cfg[i] = img_pwm_readl(pwm_chip,
PWM_CH_CFG(i));
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);
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);
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");
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),
pwm_chip->suspend_ch_cfg[i]);
img_pwm_writel(pwm_chip, PWM_CTRL_CFG, pwm_chip->suspend_ctrl_cfg);
for (i = 0; i < pwm_chip->chip.npwm; i++)
if (pwm_chip->suspend_ctrl_cfg & BIT(i))
regmap_update_bits(pwm_chip->periph_regs,
PERIP_PWM_PDM_CONTROL,
PERIP_PWM_PDM_CONTROL_CH_MASK <<
PERIP_PWM_PDM_CONTROL_CH_SHIFT(i),
0);
return 0;
}
#endif /* CONFIG_PM */
SIMPLE_DEV_PM_OPS(img_pwm_pm_ops, img_pwm_suspend, img_pwm_resume);
static struct platform_driver img_pwm_driver = { static struct platform_driver img_pwm_driver = {
.driver = { .driver = {
.name = "img-pwm", .name = "img-pwm",
.pm = &img_pwm_pm_ops,
.of_match_table = img_pwm_of_match, .of_match_table = img_pwm_of_match,
}, },
.probe = img_pwm_probe, .probe = img_pwm_probe,