Re: [PATCH v4 09/20] dt-bindings: display: renesas,rzg2l-du: Add support for RZ/G3E SoC

[Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>]

Hi Rob,
Thanks for your review.


On Mon, Feb 09, 2026 at 06:11:08PM -0600, Rob Herring wrote:
> On Mon, Feb 02, 2026 at 12:57:40PM +0100, Tommaso Merciai wrote:
> > The RZ/G3E Soc has 2 LCD controller (LCDC), contain a Frame Compression
> > Processor (FCPVD), a Video Signal Processor (VSPD), Video Signal
> > Processor (VSPD), and Display Unit (DU).
> > 
> >  - LCDC0 supports DSI and LVDS (single or dual-channel) outputs.
> >  - LCDC1 supports DSI, LVDS (single-channel), and RGB outputs.
> > 
> > Add new SoC-specific compatible string 'renesas,r9a09g047-du'.
> > 
> > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> > ---
> > 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.
> > 
> > v2->v3:
> >  - No changes.
> > 
> > v3->v4:
> >  - No changes.
> > 
> >  .../bindings/display/renesas,rzg2l-du.yaml    | 54 +++++++++++++++++++
> >  1 file changed, 54 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml b/Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml
> > index 2cc66dcef870..55e3fcff7030 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:
> > @@ -53,6 +54,12 @@ properties:
> >    power-domains:
> >      maxItems: 1
> >  
> > +  renesas,id:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    enum: [0, 1]
> > +    description: |
> > +      DU instance number.
> 
> If we wanted instance numbers, there would be a common property. So why 
> is this needed? What's the difference between instances besides the 
> ports?

renesas,id was introduce because:

 - LCDC0 supports DSI and LVDS (single or dual-channel) outputs.
 - LCDC1 supports DSI, LVDS (single-channel), and RGB outputs.

I will model the hardware without renesas,id.
I just used renesas,id because of the above reason.

Kind Regards,
Tommaso

> 
> Rob