diff mbox series

[2/6] pwm: stm32: Search an appropriate duty_cycle if period cannot be modified

Message ID f0c50df31daa3d6069bfa8d7fb3e71fae241b026.1743844730.git.u.kleine-koenig@baylibre.com (mailing list archive)
State New
Headers show
Series pwm: Some fixes preparing chardev support | expand

Commit Message

Uwe Kleine-König April 5, 2025, 9:27 a.m. UTC
If another channel is already enabled period must not be modified. If
the requested period is smaller than this unchangable period the driver
is still supposed to search a duty_cycle according to the usual rounding
rules.

So don't set the duty_cycle to 0 but continue to determine an
appropriate value for ccr.

Fixes: deaba9cff809 ("pwm: stm32: Implementation of the waveform callbacks")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
---
 drivers/pwm/pwm-stm32.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
index a59de4de18b6..ec2c05c9ee7a 100644
--- a/drivers/pwm/pwm-stm32.c
+++ b/drivers/pwm/pwm-stm32.c
@@ -103,22 +103,16 @@  static int stm32_pwm_round_waveform_tohw(struct pwm_chip *chip,
 		if (ret)
 			goto out;
 
-		/*
-		 * calculate the best value for ARR for the given PSC, refuse if
-		 * the resulting period gets bigger than the requested one.
-		 */
 		arr = mul_u64_u64_div_u64(wf->period_length_ns, rate,
 					  (u64)NSEC_PER_SEC * (wfhw->psc + 1));
 		if (arr <= wfhw->arr) {
 			/*
-			 * requested period is small than the currently
+			 * requested period is smaller than the currently
 			 * configured and unchangable period, report back the smallest
-			 * possible period, i.e. the current state; Initialize
-			 * ccr to anything valid.
+			 * possible period, i.e. the current state and return 1
+			 * to indicate the wrong rounding direction.
 			 */
-			wfhw->ccr = 0;
 			ret = 1;
-			goto out;
 		}
 
 	} else {