> From: JinGoo Han <jg1.han@xxxxxxxxxxx> > > Hi, Banajit. Hi Jingoo, >> >> Signed-off-by: Banajit Goswami <banajit.g@xxxxxxxxxxx> >> --- ... <snip> ... >> + .pwm_period_ns = 78770, > Please use 1000 as pwm_period_ns instead of 78770 as follows: > - .pwm_period_ns = 78770, > + .pwm_period_ns = 1000, > Yes, I will modify the period value and send updated patch > The value '78770' makes noise related to resonance at LCD board. > > I will explain how I get the value of PWM period. > > The SMDK boards use 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 > = 1000 ns > Thanks for the explanation. > You can find LT3591 datasheet easily on the Internet. Please refer to it > for more information. > Good luck. Thanks you. >> + .init = smdkv310_backlight_init, ... <snip> ... > Regards, Banajit -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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