Re: [PATCH v5 2/2] arm64: dts: rockchip: add RK3588 DP carrier from Theobroma Systems

[Quentin Schulz]

Hi Heiko,

On 9/30/26 6:25 PM, Heiko Stuebner wrote:
> From: Heiko Stuebner <heiko.stuebner@xxxxxxxxx>
>
> The DisplayPort carrier is a very simple baseboard only providing serial,
> ethernet and a displayport output.
>
> But its main functionality is that it routes the Analogix eDP controller
> to this DisplayPort output, which allows to test that controller simply
> by hooking it up to a suitable monitor.
>
> The Analogix-DP controller supports eDP 1.3 and DP 1.2, so can drive
> both eDP displays as well as full DP monitors. It does not support DP+
> so passive DP-to-HDMI adapters won't work.
>
> Signed-off-by: Heiko Stuebner <heiko.stuebner@xxxxxxxxx>
> ---
>   arch/arm64/boot/dts/rockchip/Makefile         |   1 +
>   .../rk3588-tiger-displayport-carrier.dts      | 113 ++++++++++++++++++
>   2 files changed, 114 insertions(+)
>   create mode 100644 arch/arm64/boot/dts/rockchip/rk3588-tiger-displayport-carrier.dts
>
> diff --git a/arch/arm64/boot/dts/rockchip/Makefile b/arch/arm64/boot/dts/rockchip/Makefile
> index 2edc9c0aceb5..bf80afba2351 100644
> --- a/arch/arm64/boot/dts/rockchip/Makefile
> +++ b/arch/arm64/boot/dts/rockchip/Makefile
> @@ -217,6 +217,7 @@ dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-rock-5b-plus.dtb
>   dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-rock-5b-plus-radxa-cam4k-cam0.dtbo
>   dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-rock-5b-plus-radxa-cam4k-cam1.dtbo
>   dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-rock-5t.dtb
> +dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-tiger-displayport-carrier.dtb
>   dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-tiger-haikou.dtb
>   dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-tiger-haikou-video-demo.dtbo
>   dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-toybrick-x0.dtb
> diff --git a/arch/arm64/boot/dts/rockchip/rk3588-tiger-displayport-carrier.dts b/arch/arm64/boot/dts/rockchip/rk3588-tiger-displayport-carrier.dts
> new file mode 100644
> index 000000000000..f6e95047fd5f
> --- /dev/null
> +++ b/arch/arm64/boot/dts/rockchip/rk3588-tiger-displayport-carrier.dts
> @@ -0,0 +1,113 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright (c) 2024 Cherry Embedded Solutions GmbH
> + */
> +
> +/dts-v1/;
> +#include <dt-bindings/soc/rockchip,vop2.h>
> +#include "rk3588-tiger.dtsi"
> +
> +/ {
> +	model = "Theobroma Systems RK3588-Q7 SoM on Tiger Displayport Carrier v1";
> +	compatible = "tsd,rk3588-tiger-displayport-carrier", "tsd,rk3588-tiger", "rockchip,rk3588";
> +
> +	aliases {
> +		ethernet0 = &gmac0;
> +	};
> +
> +	chosen {
> +		stdout-path = "serial2:115200n8";
> +	};
> +
> +	dp-connector {
> +		compatible = "dp-connector";
> +		dp-pwr-supply = <&vcc3v3_baseboard>;
> +		/* Q7_DP_HPD# but Q7_HDMI_HPD# could be used too */

Yes, but I believe the signal would then be active high instead 
(Q7_HDMI_HPD# as seen on Q7 golden fingers is inverted before reaching 
the SoC pin while Q7_DP_HPD# is directly routed to the SoC pin).

> +		hpd-gpios = <&gpio4 RK_PB5 GPIO_ACTIVE_LOW>;
> +		label = "dp0";

Is this required? (Not according to my reading of the DT binding) 
Because I don't see DP0 (or dp0) written on the board (nor in the 
schematics where it's marked (on board and schematics) as P2). Not a 
biggie in any case.

> +		pinctrl-0 = <&edp0_hpd_l>;
> +		pinctrl-names = "default";
> +		type = "full-size";
> +
> +		port {
> +			dp_con_in: endpoint {
> +				remote-endpoint = <&edp0_out_con>;
> +			};
> +		};
> +	};
> +
> +	vcc3v3_baseboard: regulator-vcc3v3-baseboard {
> +		compatible = "regulator-fixed";
> +		regulator-name = "vcc3v3_baseboard";
> +		regulator-always-on;
> +		regulator-boot-on;
> +		regulator-min-microvolt = <3300000>;
> +		regulator-max-microvolt = <3300000>;
> +		vin-supply = <&vcc5v0_baseboard>;
> +	};
> +
> +	vcc5v0_baseboard: regulator-vcc5v0-baseboard {
> +		compatible = "regulator-fixed";
> +		regulator-name = "vcc5v0_baseboard";
> +		regulator-always-on;
> +		regulator-boot-on;
> +		regulator-min-microvolt = <5000000>;
> +		regulator-max-microvolt = <5000000>;
> +	};
> +};
> +
> +&edp0 {
> +	status = "okay";
> +};
> +
> +&edp0_in {
> +	edp0_in_vp2: endpoint {
> +		remote-endpoint = <&vp2_out_edp0>;
> +	};
> +};
> +
> +&edp0_out {
> +	edp0_out_con: endpoint {
> +		remote-endpoint = <&dp_con_in>;
> +	};
> +};
> +
> +&gmac0 {
> +	status = "okay";
> +};
> +
> +&hdptxphy0 {
> +	status = "okay";
> +};
> +
> +&mmu600_pcie {
> +	status = "disabled";
> +};
> +
> +&pinctrl {
> +	edp0 {
> +		edp0_hpd_l: edp0-hpd-l-pin {
> +			rockchip,pins = <4 RK_PB5 RK_FUNC_GPIO &pcfg_pull_up>;

I believe we could also use pcfg_pull_none as we have an external 
pull-up on the carrierboard with R15 but it doesn't matter much I think :)

> +		};
> +	};
> +};
> +
> +&uart2 {
> +	pinctrl-0 = <&uart2m2_xfer>;

This property is already in rk3588-tiger.dtsi so you can remove it here.

Cheers,
Quentin