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Message-Id: <20230711200905.6464-1-aarongt.shen@gmail.com>
Date: Wed, 12 Jul 2023 04:09:05 +0800
From: Guiting Shen <aarongt.shen@...il.com>
To: claudiu.beznea@...rochip.com
Cc: thierry.reding@...il.com, u.kleine-koenig@...gutronix.de,
nicolas.ferre@...rochip.com, alexandre.belloni@...tlin.com,
linux-arm-kernel@...ts.infradead.org, linux-pwm@...r.kernel.org,
linux-kernel@...r.kernel.org, Guiting Shen <aarongt.shen@...il.com>
Subject: [PATCH v3] pwm: atmel: Enable clk when pwm already enabled in bootloader
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 <aarongt.shen@...il.com>
---
drivers/pwm/pwm-atmel.c | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index cdbc23649032..f8f1fbb8732d 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;
@@ -504,8 +529,15 @@ 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 remove_pwmchip;
+
return ret;
+remove_pwmchip:
+ pwmchip_remove(&atmel_pwm->chip);
+
unprepare_clk:
clk_unprepare(atmel_pwm->clk);
return ret;
--
2.25.1
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