Hi Hpilipp,

On Thu, 2015-10-29 at 16:40 +0100, Philipp Zabel wrote:

Hi YH,

Am Donnerstag, den 22.10.2015, 23:12 +0800 schrieb YH Huang:

quoted

In the case of the panel disabled by the bootloader,
your patch still has the following code and always enables the backlight
in the probe function.
pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
-						  GPIOD_OUT_HIGH);

You are right.

quoted

What do you think if I remove these two lines in my patch?
if (pb->enable_gpio)
	gpiod_direction_output(pb->enable_gpio, 0);

That won't work if the gpio is still configured as input. How about I
add the GPIOD_ASIS change to my patch you remove that and the above from
yours?

I revise these two lines 
if (pb->enable_gpio)
	gpiod_direction_output(pb->enable_gpio, 0);
into
if (pb->enable_gpio) {
	if(gpiod_get_value(pb->enable_gpio) = 0)
		gpiod_direction_output(pb->enable_gpio, 0);
	else
		gpiod_direction_output(pb->enable_gpio, 1);
}

I am not sure what "phandle" is working for.
My change is like your patch but remove the "phandle related" and
"gpiod_get_direction(pb->enable_gpio) = GPIOF_DIR_OUT".
Do we really need these?

Also, do you think it is right that I do the "pwm_enable(pb->pwm);"
before "gpiod_set_value(pb->enable_gpio, 1);" in power on function?

Regards,
YH Huang