Jingoo Han wrote:
>
> The SMDK board uses LT3591 as backlight LED driver of LTE480WV LCD.
> According to the LT3591 datasheet, the switching frequency should
> be 1MHz. So, PWM period is calculated by following formula:
>
> PWM period = 1/switching frequency
> = 1/1MHz
> = 1000ns
>
> Thus, the PWM backlight period should be 1000ns.
>
> Signed-off-by: Jingoo Han <jg1.han@xxxxxxxxxxx>
> ---
> arch/arm/mach-s5pv210/mach-smdkv210.c | 1 +
> 1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-s5pv210/mach-smdkv210.c b/arch/arm/mach-
> s5pv210/mach-smdkv210.c
> index a9106c3..8662ef6 100644
> --- a/arch/arm/mach-s5pv210/mach-smdkv210.c
> +++ b/arch/arm/mach-s5pv210/mach-smdkv210.c
> @@ -273,6 +273,7 @@ static struct samsung_bl_gpio_info
> smdkv210_bl_gpio_info = {
>
> static struct platform_pwm_backlight_data smdkv210_bl_data = {
> .pwm_id = 3,
> + .pwm_period_ns = 1000,
> };
>
> static void __init smdkv210_map_io(void)
> --
> 1.7.1
OK, will apply.
But when I'm looking at this in other case, we need to update the default
value of pwm_period_ns?
Let me check.
(Cc'ed Mark Brown)
Mark,
If switch frequency is 1kHz, the value of pwm_period_ns should be 1000000 at
mach-crag6410.c not 100000?
Thanks.
Best regards,
Kgene.
--
Kukjin Kim <kgene.kim@xxxxxxxxxxx>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.
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