Hi Biju,
On Sun, Aug 09, 2020 at 09:17:42AM +0000, Biju Das wrote:
> > Subject: Re: [PATCH] ARM: dts: iwg20d-q7-common: Fix touch controller
> > probe failure
> >
> > Hi Biju,
> >
> > Thank you for the patch.
> >
> > On Fri, Aug 07, 2020 at 04:20:38PM +0100, Biju Das wrote:
> > > Remove powerdown-gpios property from lvds-receiver node as it results
> > > in touch controller driver probe failure.
> > > As per the iWave RZ/G1M schematic, the signal LVDS_PPEN controls
> > > supply voltage for touch panel, LVDS receiver and RGB LCD panel.
> >
> > If it controls the supply voltage, shouldn't it be modelled as a regulator ?
> > Dropping it completely would rely on the boot loader powering the display
> > on and keeping it powered, which isn't very nice.
>
> On the schematic LVDS_PPEN, controls the voltage VCC_3V3_TFT1, which supplies voltage to
> LVDS receiver, Touch controller and RGB LCD Panel.
>
> I agree, it should be modelled as a regulator and this regulator should present in
> all these devices nodes right(LVDS receiver, Touch controller and RGB LCD Panel),
> not just on LVDS receiver node? Please share your views on this.
Correct, that's what I would recommend.
> > > Fixes: 6f89dd9e9325 ("ARM: dts: iwg20d-q7-common: Add LCD support")
> > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-
> > lad.rj@xxxxxxxxxxxxxx>
> > > ---
> > > arch/arm/boot/dts/iwg20d-q7-common.dtsi | 1 -
> > > 1 file changed, 1 deletion(-)
> > >
> > > diff --git a/arch/arm/boot/dts/iwg20d-q7-common.dtsi
> > > b/arch/arm/boot/dts/iwg20d-q7-common.dtsi
> > > index ebbe1518ef8a..4c8b9a6b0125 100644
> > > --- a/arch/arm/boot/dts/iwg20d-q7-common.dtsi
> > > +++ b/arch/arm/boot/dts/iwg20d-q7-common.dtsi
> > > @@ -57,7 +57,6 @@
> > >
> > > lvds-receiver {
> > > compatible = "ti,ds90cf384a", "lvds-decoder";
> > > -powerdown-gpios = <&gpio7 25 GPIO_ACTIVE_LOW>;
> > >
> > > ports {
> > > #address-cells = <1>;
--
Regards,
Laurent Pinchart
