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authorEd Blake <ed.blake@sondrel.com>2017-10-02 12:51:47 +0300
committerThierry Reding <thierry.reding@gmail.com>2017-11-15 12:38:04 +0300
commita18afce522e8c469132e740f840f2b95b2008987 (patch)
tree7bab12668eb638bc68806675f9a5fca78c90cb42
parent2bd6bf03f4c1c59381d62c61d03f6cc3fe71f66e (diff)
downloadlinux-a18afce522e8c469132e740f840f2b95b2008987.tar.xz
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>
-rw-r--r--drivers/pwm/pwm-img.c66
1 files changed, 65 insertions, 1 deletions
diff --git a/drivers/pwm/pwm-img.c b/drivers/pwm/pwm-img.c
index 2fb30deee345..b54daf2917bf 100644
--- a/drivers/pwm/pwm-img.c
+++ b/drivers/pwm/pwm-img.c
@@ -52,6 +52,8 @@
*/
#define MIN_TMBASE_STEPS 16
+#define IMG_PWM_NPWM 4
+
struct img_pwm_soc_data {
u32 max_timebase;
};
@@ -66,6 +68,8 @@ struct img_pwm_chip {
int max_period_ns;
int min_period_ns;
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)
@@ -255,7 +259,7 @@ static int img_pwm_probe(struct platform_device *pdev)
pwm->chip.dev = &pdev->dev;
pwm->chip.ops = &img_pwm_ops;
pwm->chip.base = -1;
- pwm->chip.npwm = 4;
+ pwm->chip.npwm = IMG_PWM_NPWM;
ret = pwmchip_add(&pwm->chip);
if (ret < 0) {
@@ -291,9 +295,69 @@ static int img_pwm_remove(struct platform_device *pdev)
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 = {
.driver = {
.name = "img-pwm",
+ .pm = &img_pwm_pm_ops,
.of_match_table = img_pwm_of_match,
},
.probe = img_pwm_probe,