Re: [PATCH/RFC 12/12] arm64: dts: renesas: Add EK874 board with idk-2121wr display support

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Fabrizio,

On Fri, Aug 2, 2019 at 9:35 AM Fabrizio Castro
<fabrizio.castro@bp.renesas.com> wrote:
> The EK874 is advertised as compatible with panel IDK-2121WR from
> Advantech, however the panel isn't sold alongside the board.
> A new dts, adding everything that's required to get the panel to
> to work with the EK874, is the most convenient way to support the
> EK874 when it's connected to the IDK-2121WR.
>
> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>

Thanks for your patch!

> --- /dev/null
> +++ b/arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts
> @@ -0,0 +1,112 @@

[...]

> +       panel-lvds {
> +               compatible = "advantech,idk-2121wr", "panel-lvds";
> +
> +               width-mm = <476>;
> +               height-mm = <268>;
> +
> +               data-mapping = "vesa-24";
> +
> +               panel-timing {
> +                       clock-frequency = <148500000>;
> +                       hactive = <1920>;
> +                       vactive = <1080>;
> +                       hsync-len = <44>;
> +                       hfront-porch = <88>;
> +                       hback-porch = <148>;
> +                       vfront-porch = <4>;
> +                       vback-porch = <36>;
> +                       vsync-len = <5>;
> +               };
> +
> +               ports {
> +                       #address-cells = <1>;
> +                       #size-cells = <0>;
> +
> +                       port@0 {
> +                               reg = <0>;
> +                               lvds0_panel_in: endpoint {
> +                                       remote-endpoint = <&lvds0_out>;
> +                               };
> +                       };
> +
> +                       port@1 {
> +                               reg = <1>;
> +                               lvds1_panel_in: endpoint {
> +                                       remote-endpoint = <&lvds1_out>;
> +                               };
> +                       };
> +               };
> +       };
> +};

[...]

> +&lvds0 {
> +       renesas,swap-data;
> +
> +       ports {
> +               port@1 {
> +                       lvds0_out: endpoint {
> +                               remote-endpoint = <&lvds0_panel_in>;
> +                       };
> +               };
> +       };
> +};
> +
> +&lvds1 {
> +       status = "okay";
> +
> +       clocks = <&cpg CPG_MOD 727>, <&x13_clk>, <&extal_clk>;
> +       clock-names = "fck", "dclkin.0", "extal";
> +
> +       ports {
> +               port@1 {
> +                       lvds1_out: endpoint {
> +                               remote-endpoint = <&lvds1_panel_in>;
> +                       };
> +               };
> +       };
> +};

Shouldn't the actual panel definition, and the lvds remote-endpoint setup,
be extracted into a separate .dtsi, to be included here?

Cfr. arch/arm/boot/dts/r8a77xx-aa104xd12-panel.dtsi and
arch/arm/boot/dts/r8a77xx-aa121td01-panel.dtsi.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds