Re: [PATCH v6 10/21] dt-bindings: display: renesas,rzg2l-du: Add support for RZ/G3E SoC

Tommaso Merciai
2026-04-08T14:02:33Z

Hi Laurent,
Thanks for your review.

On 4/8/26 14:24, Laurent Pinchart wrote:
> On Wed, Apr 08, 2026 at 12:36:55PM +0200, Tommaso Merciai wrote:
>> The RZ/G3E SoC has 2 LCD controllers (LCDC), each containing a Frame
>> Compression Processor (FCPVD), a Video Signal Processor (VSPD), and a
>> Display Unit (DU).
>>
>> - LCDC0 supports DSI and LVDS (single or dual-channel) outputs.
>> - LCDC1 supports DSI, LVDS (single-channel), and RGB outputs.
>>
>> Add a new SoC-specific compatible string 'renesas,r9a09g047-du'.
>>
>> Extend patternProperties from "^port@[0-1]$" to "^port@[0-3]$" to
>> allow up to four output ports, and explicitly disable port@2 and port@3
>> for existing SoCs that do not expose them.
>>
>> Describe the four output ports of the RZ/G3E DU:
>>
>> - port@0: DSI (available on both LCDC instances)
>> - port@1: DPAD / parallel RGB (LCDC1 only)
>> - port@2: LVDS channel 0 (LCDC0 only)
>> - port@3: LVDS channel 1 (available on both LCDC instances)
>>
>> Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
>> ---
>> v5->v6:
>> - Extend patternProperties from "^port@[0-1]$" to "^port@[0-3]$" and
>> explicitly disable port@2 and port@3 for existing SoCs that do not expose
>> them.
>> - Reworked ports numbering + improved/fixed ports descriptions in the
>> bindings documentation.
>> - Improved commit body.
>>
>> v4->v5:
>> - Dropped renesas,id property and updated bindings
>> accordingly.
>>
>> v2->v3:
>> - No changes.
>>
>> v2->v3:
>> - No changes.
>>
>> v1->v2:
>> - Use single compatible string instead of multiple compatible strings
>> for the two DU instances, leveraging a 'renesas,id' property to
>> differentiate between DU0 and DU1.
>> - Updated commit message accordingly.
>>
>> .../bindings/display/renesas,rzg2l-du.yaml | 30 ++++++++++++++++++-
>> 1 file changed, 29 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml b/Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml
>> index 5add3b832eab..32da0b5ec88c 100644
>> --- a/Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml
>> +++ b/Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml
>> @@ -20,6 +20,7 @@ properties:
>> - enum:
>> - renesas,r9a07g043u-du # RZ/G2UL
>> - renesas,r9a07g044-du # RZ/G2{L,LC}
>> + - renesas,r9a09g047-du # RZ/G3E
>> - renesas,r9a09g057-du # RZ/V2H(P)
>> - items:
>> - enum:
>> @@ -61,7 +62,7 @@ properties:
>> model-dependent. Each port shall have a single endpoint.
>>
>> patternProperties:
>> - "^port@[0-1]$":
>> + "^port@[0-3]$":
>> $ref: /schemas/graph.yaml#/properties/port
>> unevaluatedProperties: false
>>
>> @@ -103,6 +104,8 @@ allOf:
>> port@0:
>> description: DPI
>> port@1: false
>> + port@2: false
>> + port@3: false
>>
>> required:
>> - port@0
>> @@ -119,6 +122,8 @@ allOf:
>> description: DSI
>> port@1:
>> description: DPI
>> + port@2: false
>> + port@3: false
>>
>> required:
>> - port@0
>> @@ -135,9 +140,32 @@ allOf:
>> port@0:
>> description: DSI
>> port@1: false
>> + port@2: false
>> + port@3: false
>>
>> required:
>> - port@0
>> + - if:
>> + properties:
>> + compatible:
>> + contains:
>> + const: renesas,r9a09g047-du
>> + then:
>> + properties:
>> + ports:
>> + properties:
>> + port@0:
>> + description: DSI
>> + port@1:
>> + description: DPAD
>> + port@2:
>> + description: LVDS, Channel 0
>> + port@3:
>> + description: LVDS, Channel 1
>> +
>> + required:
>> + - port@0
>> + - port@3
>
> Why are ports 1 and 2 not required ?

About this we had a similar discussion on v5[0]
We are using the same compatible and:

- LCDC0 supports DSI and LVDS (single or dual-channel) outputs.
|
--> then has:
port@0
port@2
port@3

- LCDC1 supports DSI, LVDS (single-channel), and RGB outputs.
|
--> then has:
port@0
port@1
port@3

Then port@1 is required for DU1 but not for DU0.
Same port@2 is required for DU0 but not for DU1.

[0]
https://patchwork.kernel.org/project/linux-renesas-soc/patch/ca022fdbba5236c36e0cb3095db4c31e8e0cb1b8.1770996493.git.tommaso.merciai.xr@bp.renesas.com/

Kind Regards,
Tommaso

>
>>
>> examples:
>> # RZ/G2L DU
>