Re: [PATCH v4 2/7] dt-bindings: display: bridge: Document Renesas R-Car V4H DSC bindings
From: Tomi Valkeinen
Date: Mon Jun 15 2026 - 07:06:38 EST
Hi Geert,
On 15/06/2026 12:24, Geert Uytterhoeven wrote:
Hi Tomi,
On Mon, 15 Jun 2026 at 08:28, Tomi Valkeinen
<tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx> wrote:
From: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
The Renesas DSC Display Stream Compression is a bridge embedded in the
Renesas R-Car V4H SoC. The bridge performs VESA DSC encoding of up to
8k or 400 Mpixel/s .
Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
[tomi.valkeinen: fix the example]
Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Thanks for the update!
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/renesas,dsc.yaml
@@ -0,0 +1,99 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/renesas,dsc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas R-Car DSC Display Stream Compression
+
+maintainers:
+ - Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
+
+description: |
+ This binding describes the VESA DSC Display Stream Compression encoder
+ embedded in the Renesas R-Car V4H SoC. The encoder supports all DSC1.1
+ encoding mechanisms, configurable bits-per-pixel, resolution up to 8k.
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - renesas,r8a779g0-dsc
+ - const: renesas,rcar-dsc
Please do not introduce new "renesas,rcar" fallback compatible values,
unless you are adding new support for a hardware block that is present
in SoCs belonging to multiple (nowadays I would say at least three)
R-Car generations. The DSC is only found in R-Car Gen4 SoCs, so
"renesas,rcar-gen4-dsc" sounds more appropriate.
Ok.
However, so far R-Car V4H is the only R-Car Gen4 SoC that has a DSC.
Right. Even "renesas,rcar-gen4-dsc" feels a bit too wide.
None of the other rcar du related bindings define fallback compatibles. So maybe we can just keep "renesas,r8a779g0-dsc" and name the file "renesas,r8a779g0-dsc.yaml" (which was the review comment I'm trying to resolve with this change).
Even the very similar R-Car V4M does not seem to have it.I'm not that familiar with DSC functionality, but my understanding is that it's not DSI or DP specific, it just outputs packed parallel video. I couldn't find details about X5H's DSC, it could even be the same block (or not).
R-Car X5H has DSC-functionality integrated in its DisplayPort TX
controller, so that seems to be a different implementation?
Tomi