Re: [PATCH] pwm-backlight: fix the panel power sequence

[Lee Jones]

On Wed, 14 Oct 2015, YH Huang wrote:

> Hi all,
> 
> If you have any suggestion, please let me know.
> Thanks.

Please don't do that.

If you think the patch has fallen through the gaps, please just RESEND
it, like [RESEND vX] $subject.

> On Wed, 2015-09-16 at 22:42 +0800, YH Huang wrote:
> > In order to match the panel power sequence, disable the enable_gpio
> > in the probe function. Also, reorder the code in the power_on and
> > power_off function to match the timing.
> > 
> > Signed-off-by: YH Huang <yh.huang@xxxxxxxxxxxx>
> > ---
> >  drivers/video/backlight/pwm_bl.c |   15 +++++++++------
> >  1 file changed, 9 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> > index eff379b..99eca1e 100644
> > --- a/drivers/video/backlight/pwm_bl.c
> > +++ b/drivers/video/backlight/pwm_bl.c
> > @@ -54,10 +54,11 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
> >  	if (err < 0)
> >  		dev_err(pb->dev, "failed to enable power supply\n");
> >  
> > +	pwm_enable(pb->pwm);
> > +
> >  	if (pb->enable_gpio)
> >  		gpiod_set_value(pb->enable_gpio, 1);
> >  
> > -	pwm_enable(pb->pwm);
> >  	pb->enabled = true;
> >  }
> >  
> > @@ -66,12 +67,12 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb)
> >  	if (!pb->enabled)
> >  		return;
> >  
> > -	pwm_config(pb->pwm, 0, pb->period);
> > -	pwm_disable(pb->pwm);
> > -
> >  	if (pb->enable_gpio)
> >  		gpiod_set_value(pb->enable_gpio, 0);
> >  
> > +	pwm_config(pb->pwm, 0, pb->period);
> > +	pwm_disable(pb->pwm);
> > +
> >  	regulator_disable(pb->power_supply);
> >  	pb->enabled = false;
> >  }
> > @@ -241,8 +242,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> >  	pb->dev = &pdev->dev;
> >  	pb->enabled = false;
> >  
> > -	pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
> > -						  GPIOD_OUT_HIGH);
> > +	pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable");
> >  	if (IS_ERR(pb->enable_gpio)) {
> >  		ret = PTR_ERR(pb->enable_gpio);
> >  		goto err_alloc;
> > @@ -264,6 +264,9 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> >  		pb->enable_gpio = gpio_to_desc(data->enable_gpio);
> >  	}
> >  
> > +	if (pb->enable_gpio)
> > +		gpiod_direction_output(pb->enable_gpio, 0);
> > +
> >  	pb->power_supply = devm_regulator_get(&pdev->dev, "power");
> >  	if (IS_ERR(pb->power_supply)) {
> >  		ret = PTR_ERR(pb->power_supply);
> 
> 

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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