Re: [PATCH v6 09/10] dt-bindings: display: tegra: Document 8-bit CPU parallel interface

[Mikko Perttunen <mperttunen@nvidia.com>]

On Saturday, November 7, 2026 12:51 AM Thierry Reding wrote:
> On Fri, Nov 06, 2026 at 04:48:17PM +0200, Svyatoslav Ryhel wrote:
> > пт, 6 лист. 2026 р. о 16:40 Thierry Reding <thierry.reding@kernel.org> пише:
> > >
> > > On Fri, Nov 06, 2026 at 04:11:12PM +0200, Svyatoslav Ryhel wrote:
> > > > пт, 6 лист. 2026 р. о 16:08 Thierry Reding <thierry.reding@kernel.org> пише:
> > > > >
> > > > > On Thu, Nov 05, 2026 at 04:05:09PM +0200, Svyatoslav Ryhel wrote:
> > > > > > Document 8-bit CPU parallel MIPI DBI Type B interface provided by
> > > > > > Tegra20/30 SoCs display controller.
> > > > > >
> > > > > > Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> > > > > > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > > > > > ---
> > > > > >  .../display/tegra/nvidia,tegra20-dbi.yaml     | 113 ++++++++++++++++++
> > > > > >  .../display/tegra/nvidia,tegra20-dc.yaml      |  22 ++++
> > > > > >  2 files changed, 135 insertions(+)
> > > > > >  create mode 100644 Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-dbi.yaml
> > > > > >
> > > > > [...]
> > > > > > diff --git a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-dc.yaml b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-dc.yaml
> > > > > > index 69be95afd5627..ffeb124905dbf 100644
> > > > > > --- a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-dc.yaml
> > > > > > +++ b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-dc.yaml
> > > > > > @@ -79,6 +79,16 @@ properties:
> > > > > >    rgb:
> > > > > >      type: object
> > > > > >
> > > > > > +  "#address-cells":
> > > > > > +    const: 1
> > > > > > +
> > > > > > +  "#size-cells":
> > > > > > +    const: 0
> > > > > > +
> > > > > > +patternProperties:
> > > > > > +  "^dbi@[0-1]$":
> > > > > > +    $ref: /schemas/display/tegra/nvidia,tegra20-dbi.yaml#
> > > > >
> > > > > I think it might be better to group these under a separate dbi node at
> > > > > the top-level, making it a sibling to the "rgb" node. If you add
> > > > > #address-cells and #size-cells here, I think that means technically the
> > > > > "rgb" is now in the same address space as those new dbi nodes and would
> > > > > need its own "reg" property and such.
> > > > >
> > > >
> > > > Only 1 DBI node per DC is available. Adding address/size cells means
> > > > nothing for rgb.
> > >
> > > If only one node is available, then "reg" isn't the right property.
> > > "reg" indicates we're somehow addressing the child, which applies to all
> > > children, so I don't think that would work here. A separate property
> > > would make more sense in that case.
> > >
> > 
> > Check v5 and talk to Mikko
> 
> I checked v5. I disagree.
> 
> Thierry

My mistake; if there's only one node per DC then reg isn't the right 
property.

Mikko