linux-kernel - Re: [PATCH 2/2] arm64: dts: qcom: x1p42100-lenovo-thinkbook-16: add hdmi bridge with enable pin

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Message-ID: <yfddvt44btci7hxv35hskoxliahml24mmcc4qre7s6ypc6bg5m@7v3pc5wmn7zw>
Date: Sun, 21 Dec 2025 17:23:27 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Jens Glathe <jens.glathe@...schoolsolutions.biz>
Cc: Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>, linux-arm-msm@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        Val Packett <val@...kett.cool>
Subject: Re: [PATCH 2/2] arm64: dts: qcom: x1p42100-lenovo-thinkbook-16: add
 hdmi bridge with enable pin

On Sun, Dec 21, 2025 at 09:03:30AM +0100, Jens Glathe wrote:
> On 21.12.25 03:49, Dmitry Baryshkov wrote:
> > Photos / scans of the mainboard?
> Haven't found good ones where you could even see a chip (let alone markings)
> in the vicinity of the hdmi connector.
> > Okay, I might be misunderstanding something. What do you mean here by
> > "gpio119 being used twice"?
> 
> /me trying to explain something and confusing people :) Sorry for that. The
> whole dts has actually one place where the TLMM 119 is explicitly specified,
> on the hdmi-bridge. It is defined again on the tlmm node for pinctrl as
> hdmi_bridge_en (function gpio), so far so normal. gpio 119 (on the TLMM) is
> also defined and used as edp_hpd_default on the mdss_dp3 node, there with
> function edp0_hot.
> 
> You need the hdmi_bridge_en and the edp_hpd definition in the dts for both
> to work. And both use gpio 119, on the TLMM, which might be a bit confusing.

This can't work, the pin can only be used for a single function.

> 
> with best regards
> 
> Jens
> 

-- 
With best wishes
Dmitry