Re: [PATCH 1/7] dt-bindings: display: renesas,du: Document Renesas R-Car R8A779MD M3Le

Geert Uytterhoeven
2026-04-29T10:03:06Z

Hi Marek,

Thanks for your patch!

On Sun, 19 Apr 2026 at 21:37, Marek Vasut
<marek.vasut+renesas@mailbox.org> wrote:
> Extend the Renesas DU display bindings to support the Renesas R-Car
> R8A779MD M3Le SoC. This SoC is similar to R-Car R8A77965 M3-N SoC,
> except the HDMI port@1 is not present.

"and DU1 is unused." (whatever that may mean...)

>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

> --- a/Documentation/devicetree/bindings/display/renesas,du.yaml
> +++ b/Documentation/devicetree/bindings/display/renesas,du.yaml
> @@ -42,6 +42,7 @@ properties:
> - renesas,du-r8a779a0 # for R-Car V3U compatible DU
> - renesas,du-r8a779g0 # for R-Car V4H compatible DU
> - renesas,du-r8a779h0 # for R-Car V4M compatible DU
> + - renesas,du-r8a779md # for R-Car M3Le compatible DU

I am not sure you need a new compatible value: is the DU really
different than on R-Car M3-N, or does it just lack some wiring? ...

>
> reg:
> maxItems: 1
> @@ -890,6 +891,75 @@ allOf:
> - reset-names
> - renesas,vsps
>
> + - if:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - renesas,du-r8a779md
> + then:
> + properties:
> + clocks:
> + minItems: 3
> + items:
> + - description: Functional clock for DU0
> + - description: Functional clock for DU1

... E.g. you still have a module clock for DU1 (the documentation
for R-Car M3Le does not mention any changes in clocks).

> + - description: Functional clock for DU3
> + - description: DU_DOTCLKIN0 input clock
> + - description: DU_DOTCLKIN1 input clock

... E.g. the package is documented to have pin DU_DOTCLKIN1.

> + - description: DU_DOTCLKIN3 input clock
> +
> + clock-names:
> + minItems: 3
> + items:
> + - const: du.0
> + - const: du.1
> + - const: du.3
> + - pattern: '^dclkin\.[013]$'
> + - pattern: '^dclkin\.[013]$'
> + - pattern: '^dclkin\.[013]$'
> +
> + interrupts:
> + minItems: 3
> + maxItems: 3

... E.g. you still have an interrupt for DU1 (the documentation
for R-Car M3Le does not mention any changes in interrupts).

> +
> + resets:
> + minItems: 2
> + maxItems: 2
> +
> + reset-names:
> + items:
> + - const: du.0
> + - const: du.3
> +
> + ports:
> + properties:
> + port@0:
> + description: DPAD 0
> + port@1: false

Perhaps port@1 can be present (and thus required), but left unconnected
instead?

> + port@2:
> + description: LVDS 0
> + port@3: false
> +
> + required:
> + - port@0
> + - port@2
> +
> + renesas,cmms:
> + minItems: 3
> + maxItems: 3
> +
> + renesas,vsps:
> + minItems: 3
> + maxItems: 3

Your arch/arm64/boot/dts/renesas/r8a779md.dtsi only has two entries
in renesas,cmms and renesas,vsps?

> +
> + required:
> + - clock-names
> + - interrupts
> + - resets
> + - reset-names
> + - renesas,vsps
> +
> additionalProperties: false
>
> examples:

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