Re: [PATCH] media: ir-rx51: Switch to atomic PWM API

From: Uwe Kleine-König
Date: Fri Oct 29 2021 - 07:13:00 EST


Hello Maíra,

On Thu, Oct 28, 2021 at 11:12:47AM -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/ir-rx51.c | 27 +++++++++++++--------------
> 1 file changed, 13 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/media/rc/ir-rx51.c b/drivers/media/rc/ir-rx51.c
> index a0d9c02a7588..7a643a94e181 100644
> --- a/drivers/media/rc/ir-rx51.c
> +++ b/drivers/media/rc/ir-rx51.c
> @@ -19,6 +19,7 @@
> struct ir_rx51 {
> struct rc_dev *rcdev;
> struct pwm_device *pwm;
> + struct pwm_state *state;
> struct hrtimer timer;
> struct device *dev;
> wait_queue_head_t wqueue;
> @@ -32,22 +33,22 @@ struct ir_rx51 {
>
> static inline void ir_rx51_on(struct ir_rx51 *ir_rx51)
> {
> - pwm_enable(ir_rx51->pwm);
> + ir_rx51->state->enabled = true;
> + pwm_apply_state(ir_rx51->pwm, ir_rx51->state);
> }
>
> static inline void ir_rx51_off(struct ir_rx51 *ir_rx51)
> {
> - pwm_disable(ir_rx51->pwm);
> + ir_rx51->state->enabled = false;
> + pwm_apply_state(ir_rx51->pwm, ir_rx51->state);
> }
>
> static int init_timing_params(struct ir_rx51 *ir_rx51)
> {
> - struct pwm_device *pwm = ir_rx51->pwm;
> - int duty, period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, ir_rx51->freq);
> + struct pwm_state *state = ir_rx51->state;
>
> - duty = DIV_ROUND_CLOSEST(ir_rx51->duty_cycle * period, 100);
> -
> - pwm_config(pwm, duty, period);
> + state->period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, ir_rx51->freq);
> + pwm_set_relative_duty_cycle(state, ir_rx51->duty_cycle, 100);
>
> return 0;
> }
> @@ -154,6 +155,8 @@ static int ir_rx51_open(struct rc_dev *dev)
> return res;
> }
>
> + pwm_init_state(ir_rx51->pwm, ir_rx51->state);
> +

Doing this here introduces a change in behaviour. Better do this after
pwm_get().

> return 0;
> }
>
> @@ -232,13 +235,9 @@ static int ir_rx51_probe(struct platform_device *dev)
> struct rc_dev *rcdev;
>
> pwm = pwm_get(&dev->dev, NULL);
> - if (IS_ERR(pwm)) {
> - int err = PTR_ERR(pwm);
> -
> - if (err != -EPROBE_DEFER)
> - dev_err(&dev->dev, "pwm_get failed: %d\n", err);
> - return err;
> - }
> + if (IS_ERR(pwm))
> + return dev_err_probe(&dev->dev, PTR_ERR(pwm), "pwm_get failed: %ld\n",
> + PTR_ERR(pwm));
>
> /* Use default, in case userspace does not set the carrier */
> ir_rx51.freq = DIV_ROUND_CLOSEST_ULL(pwm_get_period(pwm), NSEC_PER_SEC);

Conceptually this last hunk belongs in a separate patch. And you don't
need to repeat PTR_ERR(pwm), as dev_err_probe already emits this
information. So

return dev_err_probe(&dev->dev, PTR_ERR(pwm), "pwm_get failed\n");

should be fine.

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |

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