Re: [PATCH] media: rc: pwm-ir-tx: Switch to atomic PWM API

From: Sean Young
Date: Sat Oct 23 2021 - 13:51:10 EST


Hi Maíra,

Your patch looks good, just some very minor nits.

On Sat, Oct 23, 2021 at 02:22:46PM -0300, Maíra Canal wrote:
> Remove legacy PWM interface (pwm_config, pwm_enable, pwm_disable) and
> replace it for the atomic PWM API.
>
> Signed-off-by: Maíra Canal <maira.canal@xxxxxx>
> ---
> drivers/media/rc/pwm-ir-tx.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/rc/pwm-ir-tx.c b/drivers/media/rc/pwm-ir-tx.c
> index 4bc28d2c9cc9..dfaa6125991e 100644
> --- a/drivers/media/rc/pwm-ir-tx.c
> +++ b/drivers/media/rc/pwm-ir-tx.c
> @@ -53,6 +53,7 @@ static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
> {
> struct pwm_ir *pwm_ir = dev->priv;
> struct pwm_device *pwm = pwm_ir->pwm;
> + struct pwm_state state;
> int i, duty, period;
> ktime_t edge;
> long delta;
> @@ -60,15 +61,19 @@ static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
> period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, pwm_ir->carrier);
> duty = DIV_ROUND_CLOSEST(pwm_ir->duty_cycle * period, 100);
>
> - pwm_config(pwm, duty, period);
> + pwm_init_state(pwm, &state);
> +
> + state.duty_cycle = duty;
> + state.period = period;

There is no reason to have the period and duty local variables any more;
the result of DIV_ROUND_CLOSEST(..) can be assigned directly.

> edge = ktime_get();
>
> for (i = 0; i < count; i++) {
> if (i % 2) // space
> - pwm_disable(pwm);
> + state.enabled = false;
> else
> - pwm_enable(pwm);
> + state.enabled = true;

This could be simply:
state.enabled = (i % 2) == 0;

> + pwm_apply_state(pwm, &state);
>
> edge = ktime_add_us(edge, txbuf[i]);
> delta = ktime_us_delta(edge, ktime_get());
> @@ -76,7 +81,8 @@ static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
> usleep_range(delta, delta + 10);
> }
>
> - pwm_disable(pwm);
> + state.enabled = false;
> + pwm_apply_state(pwm, &state);
>
> return count;
> }
> --
> 2.31.1

Thanks
Sean