Re: [PATCH 1/2] arm64: dts: exynos: Link DSI panel at port@1 for TM2 board

[Andrzej Hajda <andrzej.hajda@intel.com>]

+CC: dri-devel

On 10.01.2022 16:27, Jagan Teki wrote:
> TM2 board DSI pipeline has input from MIC and output to
> s6e3ha2 panel.
>
> The existing pipeline has child nodes of ports, panel and
> MIC is remote-endpoint reference of port@0 of ports.
>
> Adding panel as another child node to DSI is unconventional
> as pipeline has ports child. However it can be true if MIC
> is added inside port node like this.
>
> dsi {
> 	compatible = "samsung,exynos5433-mipi-dsi";
> 	#address-cells = <1>;
> 	#size-cells = <0>;
>
> 	port {
> 		dsi_to_mic: endpoint {
> 			remote-endpoint = <&mic_to_dsi>;
> 		};
> 	};
>
> 	panel@0 {
> 		compatible = "samsung,s6e3hf2";
>                  reg = <0>;
>                  vdd3-supply = <&ldo27_reg>;
>                  vci-supply = <&ldo28_reg>;
>                  reset-gpios = <&gpg0 0 GPIO_ACTIVE_LOW>;
>                  enable-gpios = <&gpf1 5 GPIO_ACTIVE_HIGH>;
> 	};
> };
>
> The above pipeline is proper but it requires the DSI input MIC
> pipeline to update.
>
> This patch is trying to add panel at port@1 so-that the entire
> pipeline before to panel output is untouched.
>
> Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
>   arch/arm64/boot/dts/exynos/exynos5433-tm2.dts | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts b/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts
> index aca01709fd29..e13210c8d7e0 100644
> --- a/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts
> +++ b/arch/arm64/boot/dts/exynos/exynos5433-tm2.dts
> @@ -53,6 +53,16 @@ &cmu_disp {
>   };
>   
>   &dsi {
> +	ports {
> +		port@1 {
> +			reg = <1>;
> +
> +			dsi_out_panel: endpoint {
> +				remote-endpoint = <&dsi_in_panel>;
> +			};
> +		};
> +	};
> +
>   	panel@0 {
>   		compatible = "samsung,s6e3ha2";
>   		reg = <0>;
> @@ -60,6 +70,12 @@ panel@0 {
>   		vci-supply = <&ldo28_reg>;
>   		reset-gpios = <&gpg0 0 GPIO_ACTIVE_LOW>;
>   		enable-gpios = <&gpf1 5 GPIO_ACTIVE_HIGH>;
> +
> +		port {
> +			dsi_in_panel: endpoint {
> +				remote-endpoint = <&dsi_out_panel>;
> +			};
> +		};


As I already wrote in Exynos thread, DSI host has already parent-child 
relation with the panel - DSI host knows well who is connected to it. 
Adding another links between them is redundant and has no value added.

I have already answered in Exynos thread[1] how could you deal with the 
issue, you have.

[1]: 
https://lore.kernel.org/dri-devel/e541c52b-9751-933b-5eac-783dd0ed9056@intel.com/


Regards

Andrzej


>   	};
>   };
>