Re: [PATCH] exynos: pwm: Deal with a PWM at 100%

[Minkyu Kang]

Dear Simon Glass,

2021년 11월 4일 (목) 04:21, Simon Glass <s...@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 <s...@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, &regs->tcntb0 + offset);
>                 writel(tcmp, &regs->tcmpb0 + offset);
> --
> 2.34.0.rc0.344.g81b53c2807-goog


> applied to u-boot-samsung.

Thanks.
-- 
Thanks. Minkyu Kang.