[PATCH] pwm: atmel: enable clk when pwm already enabled in bootloader

Guiting Shen
2023-07-10T14:43:19Z

The driver would never call clk_eanble() if the pwm channel already
enable in bootloader which lead to dump the warning message of "the pwm
clk already disabled" when poweroff the pwm channel.

Add atmel_pwm_enanle_clk_if_on() in probe function to enable clk if the
pwm channel already enabled in bootloader.

Signed-off-by: Guiting Shen <aarongt.shen@gmail.com>
---
drivers/pwm/pwm-atmel.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index cdbc23649032..385f12eb604c 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -464,6 +464,29 @@ 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)
+{
+ u32 sr, i;
+ int err;
+
+ 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, "enable clock error\n");
+ return err;
+ }
+ }
+
+ return 0;
+}
+
static int atmel_pwm_probe(struct platform_device *pdev)
{
struct atmel_pwm_chip *atmel_pwm;
@@ -504,6 +527,10 @@ static int atmel_pwm_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, atmel_pwm);

+ ret = atmel_pwm_enable_clk_if_on(atmel_pwm);
+ if (ret < 0)
+ goto unprepare_clk;
+
return ret;

unprepare_clk:
--
2.25.1