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....@samsung.com> > --- > 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....@samsung.com>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html