[PATCH 1/3] drm/bridge: it6505: Modified power sequence

[Robert Foss]

Hi,




On Tue, Jul 12, 2022, 11:41 Chen-Yu Tsai <wenst at chromium.org> wrote:

> On Tue, Jul 12, 2022 at 4:08 PM Robert Foss <robert.foss at linaro.org>
> wrote:
> >
> > Hi Allen,
> >
> > On Thu, 7 Jul 2022 at 10:06, allen <allen.chen at ite.com.tw> wrote:
> > >
> > > From: allen chen <allen.chen at ite.com.tw>
> > >
> > > Change power sequence to meet it6505 data sheet requirement when boot
> on.
> > >
> > > Signed-off-by: Pin-Yen Lin <treapking at chromium.org>
> > > Signed-off-by: Allen Chen <allen.chen at ite.com.tw>
> > >
> > > ---
> > >  drivers/gpu/drm/bridge/ite-it6505.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/bridge/ite-it6505.c
> b/drivers/gpu/drm/bridge/ite-it6505.c
> > > index 2d119e3016b3..aa5e0aa1af85 100644
> > > --- a/drivers/gpu/drm/bridge/ite-it6505.c
> > > +++ b/drivers/gpu/drm/bridge/ite-it6505.c
> > > @@ -3029,7 +3029,7 @@ static int it6505_init_pdata(struct it6505
> *it6505)
> > >                 return PTR_ERR(pdata->ovdd);
> > >         }
> > >
> > > -       pdata->gpiod_reset = devm_gpiod_get(dev, "reset",
> GPIOD_OUT_HIGH);
> > > +       pdata->gpiod_reset = devm_gpiod_get(dev, "reset",
> GPIOD_OUT_LOW);
> >
> > Making this change is problematic since it requires a corresponding
> > change in all of the device trees that use this device. It's against
> > policy to change this interface after it has been introduced.
> >
> > Unless anyone thinks otherwise, I would like to see this patch dropped.
>
> I think you're confusing GPIO_ACTIVE_{LOW,HIGH} flags in the device tree
> vs GPIOD_OUT_{LOW,HIGH}, which just sets the "default" state the GPIO
> should be in when it is requested.
>
> This change doesn't impact the device tree.
>

Thanks ChenYu, you are 100% right.


Reviewed-by: Robert Foss <robert.foss at linaro.org>


>
> Regards
> ChenYu
>
> > >         if (IS_ERR(pdata->gpiod_reset)) {
> > >                 dev_err(dev, "gpiod_reset gpio not found");
> > >                 return PTR_ERR(pdata->gpiod_reset);
> > > --
> > > 2.25.1
> > >
>
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