Re: [PATCH] media: dt-bindings: media: renesas,csi2: Node port@0 is not mandatory

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Niklas,

On Fri, Apr 16, 2021 at 10:05:46AM +0200, Niklas Söderlund wrote:
> On 2021-04-15 22:09:12 +0300, Laurent Pinchart wrote:
> > On Tue, Apr 13, 2021 at 05:53:46PM +0200, Niklas Söderlund wrote:
> > > When converting the binding to use the video-interfaces schemas the node
> > > port@0 was incorrectly made a mandatory property.
> > > 
> > > The port@0 node describes which CSI-2 transmitter the R-Car CSI-2
> > > receiver is connected too. Not all boards connects all CSI-2 receivers
> > > to an CSI-2 transmitter.
> > 
> > Ports are properties of the device, they should always be there,
> > regardless of connections. It's the endpoints that describe connections.
> 
> I understand what you are saying and if that is the way things are done 
> I'm fine with it. As this was brought to light by a recent change in the 
> bindings I wish to understand if this was always the case the bindings 
> have been wrong all along or not.
> 
> I only ask as because if we keep the port@0 mandatory there will be 
> board files that needs to add empty port@0 nodes as we know they are not 
> used. And as the media bindings are already quiet large for some Renesas 
> boards I want to understand this before spewing out a lot of patches 
> adding empty nodes ;-)

In my opinion port@0 should be in the SoC .dtsi, not in the board .dts.
Individual boards can then add endpoints when the CSI-2 receiver is
connected. Would that make sense for you ?

> > > Fixes: 066a94e28a23e04c ("media: dt-bindings: media: Use graph and video-interfaces schemas")
> > > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > > ---
> > >  Documentation/devicetree/bindings/media/renesas,csi2.yaml | 1 -
> > >  1 file changed, 1 deletion(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/media/renesas,csi2.yaml b/Documentation/devicetree/bindings/media/renesas,csi2.yaml
> > > index 20396f1be9993461..395484807dd5ed47 100644
> > > --- a/Documentation/devicetree/bindings/media/renesas,csi2.yaml
> > > +++ b/Documentation/devicetree/bindings/media/renesas,csi2.yaml
> > > @@ -78,7 +78,6 @@ properties:
> > >            modules connected the CSI-2 receiver.
> > >  
> > >      required:
> > > -      - port@0
> > >        - port@1
> > >  
> > >  required:

-- 
Regards,

Laurent Pinchart