[PATCH] exynos: pwm: Deal with a PWM at 100%
Minkyu Kang
promsoft at gmail.com
Tue Nov 9 10:51:04 CET 2021
Dear Simon Glass,
2021년 11월 4일 (목) 04:21, Simon Glass <sjg at chromium.org>님이 작성:
> 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 <sjg at chromium.org>
> ---
>
> 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 1afaf784dab..609025d680d 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);
> --
> 2.34.0.rc0.344.g81b53c2807-goog
> applied to u-boot-samsung.
Thanks.
--
Thanks. Minkyu Kang.
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