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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <72bq7sblm7iprtxg6oo65mit7vsheux2xatqlk3csf6sp7ersg@77p5hloqf555>
Date: Sat, 20 Dec 2025 20:52:54 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: 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 Sat, Dec 20, 2025 at 06:47:10PM +0100, Jens Glathe via B4 Relay wrote:
> From: Jens Glathe <jens.glathe@...schoolsolutions.biz>
> 
> Add TLMM 119 for hdmi bridge enable. AeoB has this gpio.

Whaat is AeoB? I don't see the GPIO being used in other place.

> In general this is the same setup as on the T14s. Since its using simple-bridge
> and also is Lenovo, we also use the same realtek,rtd2171 compatible.
> The real chip identity is not known yet. The bridge is wired with un-swapped
> lanes, though.

Is the chip marked anyhow?

> 
> As for gpio119 being used twice: It doesn't work if you don't, so it may be a case
> of TLMM multiplexing hpd for both ports.

What is the relationship between enable and HPD?

> 
> Signed-off-by: Jens Glathe <jens.glathe@...schoolsolutions.biz>
> ---
>  .../boot/dts/qcom/x1p42100-lenovo-thinkbook-16.dts | 88 ++++++++++++++++++++++
>  1 file changed, 88 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/x1p42100-lenovo-thinkbook-16.dts b/arch/arm64/boot/dts/qcom/x1p42100-lenovo-thinkbook-16.dts
> index b505a4cbb4350a962bbf779ec788265c7583bf20..80172f3059a42c8656eb682682495194015d3bbc 100644
> --- a/arch/arm64/boot/dts/qcom/x1p42100-lenovo-thinkbook-16.dts
> +++ b/arch/arm64/boot/dts/qcom/x1p42100-lenovo-thinkbook-16.dts
> @@ -78,6 +78,47 @@ camera {
>  		vdd-supply = <&vreg_cam_5p0>;
>  	};
>  
> +	hdmi-bridge {
> +		compatible = "realtek,rtd2171";
> +
> +		enable-gpios = <&tlmm 119 GPIO_ACTIVE_HIGH>;
> +
> +		pinctrl-0 = <&hdmi_hpd_default>;
> +		pinctrl-names = "default";
> +
> +		ports {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			port@0 {
> +				reg = <0>;
> +
> +				hdmi_bridge_dp_in: endpoint {
> +					remote-endpoint = <&usb_1_ss2_qmpphy_out_dp>;
> +				};
> +			};
> +
> +			port@1 {
> +				reg = <1>;
> +
> +				hdmi_bridge_tmds_out: endpoint {
> +					remote-endpoint = <&hdmi_con>;
> +				};
> +			};
> +		};
> +	};
> +
> +	hdmi-connector {
> +		compatible = "hdmi-connector";
> +		type = "a";
> +
> +		port {
> +			hdmi_con: endpoint {
> +				remote-endpoint = <&hdmi_bridge_tmds_out>;
> +			};
> +		};
> +	};
> +
>  	gpio-keys {
>  		compatible = "gpio-keys";
>  
> @@ -1038,6 +1079,14 @@ &mdss_dp1_out {
>  	link-frequencies = /bits/ 64 <1620000000 2700000000 5400000000 8100000000>;
>  };
>  
> +&mdss_dp2 {
> +	status = "okay";
> +};
> +
> +&mdss_dp2_out {
> +	link-frequencies = /bits/ 64 <1620000000 2700000000 5400000000 8100000000>;
> +};
> +
>  &mdss_dp3 {
>  	/delete-property/ #sound-dai-cells;
>  
> @@ -1327,6 +1376,19 @@ hall_int_n_default: hall-int-n-state {
>  		bias-disable;
>  	};
>  
> +	hdmi_bridge_en: hdmi-bridge-en-state {
> +		pins = "gpio119";
> +		function = "gpio";
> +		drive-strength = <16>;
> +		bias-disable;
> +	};
> +
> +	hdmi_hpd_default: hdmi-hpd-default-state {
> +		pins = "gpio126";
> +		function = "usb2_dp";
> +		bias-disable;
> +	};
> +
>  	kybd_default: kybd-default-state {
>  		pins = "gpio67";
>  		function = "gpio";
> @@ -1585,6 +1647,32 @@ &usb_1_ss2_hsphy {
>  	status = "okay";
>  };
>  
> +&usb_1_ss2_qmpphy {
> +	vdda-phy-supply = <&vreg_l2j_1p2>;
> +	vdda-pll-supply = <&vreg_l2d_0p9>;
> +
> +	/delete-property/ mode-switch;
> +	/delete-property/ orientation-switch;
> +
> +	status = "okay";
> +
> +	ports {
> +		port@0 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			/delete-node/ endpoint;
> +
> +			usb_1_ss2_qmpphy_out_dp: endpoint@0 {
> +				reg = <0>;
> +
> +				data-lanes = <0 1 2 3>;
> +				remote-endpoint = <&hdmi_bridge_dp_in>;
> +			};
> +		};
> +	};
> +};
> +
>  &usb_2 {
>  	status = "okay";
>  };
> 
> -- 
> 2.51.0
> 
> 

-- 
With best wishes
Dmitry