Commit a85e08a0 authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Uwe Kleine-König
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pwm: axi-pwmgen: Let .round_waveform_tohw() signal when request was rounded up 



The .round_waveform_tohw() is supposed to return 1 if the requested
waveform cannot be implemented by rounding down all parameters. Also
adapt the corresponding comment to better describe why the implemented
procedure is right.

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/ba451573f0218d76645f068cec78bd97802cf010.1743844730.git.u.kleine-koenig@baylibre.com


Signed-off-by: default avatarUwe Kleine-König <ukleinek@kernel.org>
parent fda6e003

drivers/pwm/pwm-axi-pwmgen.c

+7 −3
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ static int axi_pwmgen_round_waveform_tohw(struct pwm_chip *chip, 
{

	struct axi_pwmgen_waveform *wfhw = _wfhw;

	struct axi_pwmgen_ddata *ddata = axi_pwmgen_ddata_from_chip(chip);

	int ret = 0;



	if (wf->period_length_ns == 0) {

		*wfhw = (struct axi_pwmgen_waveform){
@@ -91,12 +92,15 @@ static int axi_pwmgen_round_waveform_tohw(struct pwm_chip *chip, 
		if (wfhw->period_cnt == 0) {

			/*

			 * The specified period is too short for the hardware.

			 * Let's round .duty_cycle down to 0 to get a (somewhat)

			 * valid result.

			 * So round up .period_cnt to 1 (i.e. the smallest

			 * possible period). With .duty_cycle and .duty_offset

			 * being less than or equal to .period, their rounded

			 * value must be 0.

			 */

			wfhw->period_cnt = 1;

			wfhw->duty_cycle_cnt = 0;

			wfhw->duty_offset_cnt = 0;

			ret = 1;

		} else {

			wfhw->duty_cycle_cnt = min_t(u64,

						     mul_u64_u32_div(wf->duty_length_ns, ddata->clk_rate_hz, NSEC_PER_SEC),
@@ -111,7 +115,7 @@ static int axi_pwmgen_round_waveform_tohw(struct pwm_chip *chip, 
		pwm->hwpwm, wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,

		ddata->clk_rate_hz, wfhw->period_cnt, wfhw->duty_cycle_cnt, wfhw->duty_offset_cnt);



	return 0;

	return ret;

}



static int axi_pwmgen_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_device *pwm,