pwm: atmel-hlcdc: Implement the suspend/resume hooks

Implement the suspend/resume hooks to make sure the PWM device is
restored to a correct state after a suspend.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-atmel-hlcdc.c b/drivers/pwm/pwm-atmel-hlcdc.c
index bcb6d946131d..54c6633d9b5d 100644
--- a/drivers/pwm/pwm-atmel-hlcdc.c
+++ b/drivers/pwm/pwm-atmel-hlcdc.c
@@ -191,6 +191,40 @@ static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_sama5d3_errata = {
         .div1_clk_erratum = true,
 };
 
+#ifdef CONFIG_PM_SLEEP
+static int atmel_hlcdc_pwm_suspend(struct device *dev)
+{
+        struct atmel_hlcdc_pwm *chip = dev_get_drvdata(dev);
+
+        /* Keep the periph clock enabled if the PWM is still running. */
+        if (pwm_is_enabled(&chip->chip.pwms[0]))
+                clk_disable_unprepare(chip->hlcdc->periph_clk);
+
+        return 0;
+}
+
+static int atmel_hlcdc_pwm_resume(struct device *dev)
+{
+        struct atmel_hlcdc_pwm *chip = dev_get_drvdata(dev);
+        struct pwm_state state;
+        int ret;
+
+        pwm_get_state(&chip->chip.pwms[0], &state);
+
+        /* Re-enable the periph clock it was stopped during suspend. */
+        if (!state.enabled) {
+                ret = clk_prepare_enable(chip->hlcdc->periph_clk);
+                if (ret)
+                        return ret;
+        }
+
+        return atmel_hlcdc_pwm_apply(&chip->chip, &chip->chip.pwms[0], &state);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(atmel_hlcdc_pwm_pm_ops,
+                         atmel_hlcdc_pwm_suspend, atmel_hlcdc_pwm_resume);
+
 static const struct of_device_id atmel_hlcdc_dt_ids[] = {
         {
                 .compatible = "atmel,at91sam9n12-hlcdc",
@@ -280,6 +314,7 @@ static struct platform_driver atmel_hlcdc_pwm_driver = {
         .driver = {
                 .name = "atmel-hlcdc-pwm",
                 .of_match_table = atmel_hlcdc_pwm_dt_ids,
+                .pm = &atmel_hlcdc_pwm_pm_ops,
         },
         .probe = atmel_hlcdc_pwm_probe,
         .remove = atmel_hlcdc_pwm_remove,