diff mbox series

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

Message ID 20230113083115.2590-3-nylon.chen@sifive.com (mailing list archive)
State Superseded
Headers show
Series Change PWM-controlled LED pin active mode and algorithm | expand

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conchuod/maintainers_pattern success MAINTAINERS pattern errors before the patch: 13 and now 13
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conchuod/build_rv32_defconfig success Build OK
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conchuod/build_rv64_nommu_virt_defconfig success Build OK

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) {