diff mbox series

ARM: dts: iwg20d-q7-common: Fix touch controller probe failure

Message ID 20200807152039.10961-1-biju.das.jz@bp.renesas.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show
Series ARM: dts: iwg20d-q7-common: Fix touch controller probe failure | expand

Commit Message

Biju Das Aug. 7, 2020, 3:20 p.m. UTC
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.

Fixes: 6f89dd9e9325 ("ARM: dts: iwg20d-q7-common: Add LCD support")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 arch/arm/boot/dts/iwg20d-q7-common.dtsi | 1 -
 1 file changed, 1 deletion(-)

Comments

Laurent Pinchart Aug. 8, 2020, 9:28 p.m. UTC | #1
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.

> Fixes: 6f89dd9e9325 ("ARM: dts: iwg20d-q7-common: Add LCD support")
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
>  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>;
Biju Das Aug. 9, 2020, 9:17 a.m. UTC | #2
Hi Laurent,

Thanks for the feedback.

> 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.

Cheers,
Biju
>
> > Fixes: 6f89dd9e9325 ("ARM: dts: iwg20d-q7-common: Add LCD support")
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-
> lad.rj@bp.renesas.com>
> > ---
> >  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


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Laurent Pinchart Aug. 9, 2020, 10:54 a.m. UTC | #3
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@bp.renesas.com>
> > > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-
> > lad.rj@bp.renesas.com>
> > > ---
> > >  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>;
diff mbox series

Patch

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>;