linux-kernel - Re: [PATCH] pwm: tiehrpwm: Enable EHRPWM controller before setting configuration

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Message-ID: <4dd61e57-bc6a-485d-847d-8a86b854d358@ti.com>
Date: Tue, 6 Jan 2026 18:57:11 +0530
From: "Kumar, Udit" <u-kumar1@...com>
To: Gokul Praveen <g-praveen@...com>, <j-keerthy@...com>,
	<ukleinek@...nel.org>, <linux-pwm@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
CC: <n-francis@...com>
Subject: Re: [PATCH] pwm: tiehrpwm: Enable EHRPWM controller before setting
 configuration


On 1/6/2026 4:24 PM, Gokul Praveen wrote:
> The period and duty cycle configurations does not get reflected
> after setting them using sysfs nodes. This is because at the
> end of ehrpwm_pwm_config function, the put_sync function is
> called which resets the hardware.
>
> Fix it by preventing the pwm controller from going into
> low-power mode.
>
> 'Fixes: 5f027d9b83db("pwm: tiehrpwm: Implement
> .apply() callback")'
>
> Signed-off-by: Gokul Praveen <g-praveen@...com>

No new line,  between Fixes and Signed-off-by Please ,

You can drop ' before fixes.

rest LGTM.


> ---
>   drivers/pwm/pwm-tiehrpwm.c | 22 +++++++++++++---------
>   1 file changed, 13 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
> index 7a86cb090f76..408aed70be8c 100644
> --- a/drivers/pwm/pwm-tiehrpwm.c
> +++ b/drivers/pwm/pwm-tiehrpwm.c
> @@ -237,7 +237,6 @@ static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>   	if (period_cycles < 1)
>   		period_cycles = 1;
>   
> -	pm_runtime_get_sync(pwmchip_parent(chip));
>   
>   	/* Update clock prescaler values */
>   	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
> @@ -290,12 +289,11 @@ static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>   	if (!(duty_cycles > period_cycles))
>   		ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
>   
> -	pm_runtime_put_sync(pwmchip_parent(chip));
> -
>   	return 0;
>   }
>   
> -static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
> +static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm,
> +				const struct pwm_state *state)
>   {
>   	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
>   	u16 aqcsfrc_val, aqcsfrc_mask;
> @@ -304,6 +302,13 @@ static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
>   	/* Leave clock enabled on enabling PWM */
>   	pm_runtime_get_sync(pwmchip_parent(chip));
>   
> +	ret = ehrpwm_pwm_config(chip, pwm, state->duty_cycle, state->period, state->polarity);
> +
> +	if (ret) {
> +		pm_runtime_put_sync(pwmchip_parent(chip));
> +		return ret;
> +	}
> +
>   	/* Disabling Action Qualifier on PWM output */
>   	if (pwm->hwpwm) {
>   		aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
> @@ -391,12 +396,11 @@ static int ehrpwm_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
>   		return 0;
>   	}
>   
> -	err = ehrpwm_pwm_config(chip, pwm, state->duty_cycle, state->period, state->polarity);
> -	if (err)
> -		return err;
> -
>   	if (!enabled)
> -		err = ehrpwm_pwm_enable(chip, pwm);
> +		err = ehrpwm_pwm_enable(chip, pwm, state);
> +	else
> +		err = ehrpwm_pwm_config(chip, pwm, state->duty_cycle,
> +					state->period, state->polarity);
>   
>   	return err;
>   }