Commit 00e53d0f authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Uwe Kleine-König
Browse files

pwm: Let pwm_set_waveform() succeed even if lowlevel driver rounded up 



Waveform parameters are supposed to be rounded down to the next value
possible for the hardware. However when a requested value is too small,
.round_waveform_tohw() is supposed to pick the next bigger value and
return 1. Let pwm_set_waveform() behave in the same way.

This creates consistency between pwm_set_waveform_might_sleep() with
exact=false and pwm_round_waveform_might_sleep() +
pwm_set_waveform_might_sleep() with exact=true.

The PWM_DEBUG rounding check has to be adapted to only trigger if no
uprounding happend.

Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@baylibre.com>
Tested-by: default avatarTrevor Gamblin <tgamblin@baylibre.com>
Link: https://lore.kernel.org/r/353dc6ae31be815e41fd3df89c257127ca0d1a09.1743844730.git.u.kleine-koenig@baylibre.com


Signed-off-by: default avatarUwe Kleine-König <ukleinek@kernel.org>
parent 928446a5

drivers/pwm/core.c

+7 −6
Original line number Diff line number Diff line
@@ -322,7 +322,7 @@ static int __pwm_set_waveform(struct pwm_device *pwm, 
	const struct pwm_ops *ops = chip->ops;

	char wfhw[WFHWSIZE];

	struct pwm_waveform wf_rounded;

	int err;

	int err, ret_tohw;



	BUG_ON(WFHWSIZE < ops->sizeof_wfhw);
@@ -332,16 +332,16 @@ static int __pwm_set_waveform(struct pwm_device *pwm, 
	if (!pwm_wf_valid(wf))

		return -EINVAL;



	err = __pwm_round_waveform_tohw(chip, pwm, wf, &wfhw);

	if (err)

		return err;

	ret_tohw = __pwm_round_waveform_tohw(chip, pwm, wf, &wfhw);

	if (ret_tohw < 0)

		return ret_tohw;



	if ((IS_ENABLED(CONFIG_PWM_DEBUG) || exact) && wf->period_length_ns) {

		err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_rounded);

		if (err)

			return err;



		if (IS_ENABLED(CONFIG_PWM_DEBUG) && !pwm_check_rounding(wf, &wf_rounded))

		if (IS_ENABLED(CONFIG_PWM_DEBUG) && ret_tohw == 0 && !pwm_check_rounding(wf, &wf_rounded))

			dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu]\n",

				wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,

				wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns);
@@ -382,7 +382,8 @@ static int __pwm_set_waveform(struct pwm_device *pwm, 
				wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns,

				wf_set.duty_length_ns, wf_set.period_length_ns, wf_set.duty_offset_ns);

	}

	return 0;



	return ret_tohw;

}



/**