diff mbox series

[2/2] pwm: sifive: change the PWM controlled LED algorithm

Message ID 20230113083115.2590-3-nylon.chen@sifive.com
State New
Headers
Series Change PWM-controlled LED pin active mode and algorithm |

Commit Message

Nylon Chen Jan. 13, 2023, 8:31 a.m. UTC 
  The `frac` variable represents the pulse inactive time, and the result of
this algorithm is the pulse active time. Therefore, we must reverse the
result.

Signed-off-by: Nylon Chen <nylon.chen@sifive.com>
Reviewed-by: Vincent Chen <vincent.chen@sifive.com>
---
 drivers/pwm/pwm-sifive.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c
index 62b6acc6373d..a5eda165d071 100644
--- a/drivers/pwm/pwm-sifive.c
+++ b/drivers/pwm/pwm-sifive.c
@@ -158,6 +158,7 @@  static int pwm_sifive_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	frac = DIV64_U64_ROUND_CLOSEST(num, state->period);
 	/* The hardware cannot generate a 100% duty cycle */
 	frac = min(frac, (1U << PWM_SIFIVE_CMPWIDTH) - 1);
+	frac = (1U << PWM_SIFIVE_CMPWIDTH) - 1 - frac;
 
 	mutex_lock(&ddata->lock);
 	if (state->period != ddata->approx_period) {