From dfb8470fd0b3b8a87c047b9c1765a1b9123b83b7 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Wed, 3 Nov 2021 13:21:33 -0600 Subject: [PATCH] exynos: pwm: Deal with a PWM at 100% At present the counter never hits the comparitor in this case. Add a special case. This ensures that the snow backlight works when at full brightness. Fixes: 76c2ff3e5fd video: backlight: fix pwm's duty cycle calculation Signed-off-by: Simon Glass Signed-off-by: Minkyu Kang --- drivers/pwm/exynos_pwm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pwm/exynos_pwm.c b/drivers/pwm/exynos_pwm.c index 1afaf784da..609025d680 100644 --- a/drivers/pwm/exynos_pwm.c +++ b/drivers/pwm/exynos_pwm.c @@ -43,6 +43,10 @@ static int exynos_pwm_set_config(struct udevice *dev, uint channel, tcnt = period_ns / rate_ns; tcmp = duty_ns / rate_ns; debug("%s: tcnt %u, tcmp %u\n", __func__, tcnt, tcmp); + + /* Ensure that the comparitor will actually hit the target */ + if (tcmp == tcnt) + tcmp = tcnt - 1; offset = channel * 3; writel(tcnt, ®s->tcntb0 + offset); writel(tcmp, ®s->tcmpb0 + offset); -- 2.39.5