[PATCH v6 1/2] arm64: dts: qcom: x1e78100-t14s: add hpd gpio to dp controller

Christopher Obbard christopher.obbard at linaro.org
Fri Aug 8 22:28:23 UTC 2025


Hi Johan,


On Mon, 4 Aug 2025 at 14:13, Johan Hovold <johan at kernel.org> wrote:
>
> On Thu, Jul 31, 2025 at 09:51:26PM +0100, Christopher Obbard wrote:
> > The eDP controller has an HPD GPIO. Describe it in the device tree
> > for the generic T14s model, as the HPD GPIO is used in both the
> > OLED and LCD models which inherit this device tree.
>
> > @@ -5779,6 +5779,11 @@ tlmm: pinctrl at f100000 {
> >                       gpio-ranges = <&tlmm 0 0 239>;
> >                       wakeup-parent = <&pdc>;
> >
> > +                     edp_hpd_active: edp-hpd-active-state {
>
> The node name and label needs an index as this SoC has two edp hpd pins
> as I already pointed out.

Sure. After looking at the schematics this should be called
edp0_hpd_active. I will fix this in the next revision.


> > +                             pins = "gpio119";
> > +                             function = "edp0_hot";
>
> And you also need to configure the bias somewhere as you should not rely
> on the firmware having configured things for you (as I also pointed out
> before).
>
> On my T14s the internal pull-up has been disabled.

I am still unsure of what else needs to be set here. Can you help me
with the correct settings?

Thanks,
Chris


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