The driver would never call clk_enable() if the PWM channel was already
enabled in bootloader which lead to dump the warning message "the PWM
clock already disabled" when turning off the PWM channel.
Add atmel_pwm_enable_clk_if_on() in probe function to enable clock if
the PWM channel was already enabled in bootloader.
Signed-off-by: Guiting Shen <[email protected]>
---
drivers/pwm/pwm-atmel.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index cdbc23649032..ced4ad3c68b2 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -464,6 +464,31 @@ static const struct of_device_id atmel_pwm_dt_ids[] = {
};
MODULE_DEVICE_TABLE(of, atmel_pwm_dt_ids);
+static int atmel_pwm_enable_clk_if_on(struct atmel_pwm_chip *atmel_pwm)
+{
+ unsigned int i;
+ int err;
+ u32 sr;
+
+ sr = atmel_pwm_readl(atmel_pwm, PWM_SR);
+ if (!sr)
+ return 0;
+
+ for (i = 0; i < atmel_pwm->chip.npwm; i++) {
+ if (!(sr & (1 << i)))
+ continue;
+
+ err = clk_enable(atmel_pwm->clk);
+ if (err) {
+ dev_err(atmel_pwm->chip.dev,
+ "failed to enable clock: %pe\n", ERR_PTR(err));
+ return err;
+ }
+ }
+
+ return 0;
+}
+
static int atmel_pwm_probe(struct platform_device *pdev)
{
struct atmel_pwm_chip *atmel_pwm;
@@ -496,6 +521,10 @@ static int atmel_pwm_probe(struct platform_device *pdev)
atmel_pwm->chip.ops = &atmel_pwm_ops;
atmel_pwm->chip.npwm = 4;
+ ret = atmel_pwm_enable_clk_if_on(atmel_pwm);
+ if (ret < 0)
+ goto unprepare_clk;
+
ret = pwmchip_add(&atmel_pwm->chip);
if (ret < 0) {
dev_err(&pdev->dev, "failed to add PWM chip %d\n", ret);
--
2.25.1