Re: [PATCH 3/3] dt-bindings: media: ov772x: Document endpoint props

[Jacopo Mondi <jacopo@jmondi.org>]

Hi Laurent, Prabhakar,

On Fri, Aug 21, 2020 at 12:37:35PM +0100, Lad, Prabhakar wrote:
> Hi Laurent and Jacopo
>
> On Wed, Aug 19, 2020 at 2:54 PM Laurent Pinchart
> <laurent.pinchart@ideasonboard.com> wrote:
> >
> > Hi Jacopo,
> >
> > Thank you for the patch.
> >
> > On Tue, Aug 18, 2020 at 02:20:12PM +0200, Jacopo Mondi wrote:
> > > Document endpoint properties for the parallel bus type and
> > > add them to the example.
> > >
> > > Specify a few constraints:
> > > - If the bus type is BT.656 no hsync or vsycn polarities can be
> > >   specified.
> > > - If the bus width is 10 bits, not data-shift can be applied.
> > >
> > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > > ---
> > >  .../devicetree/bindings/media/i2c/ov772x.yaml | 43 +++++++++++++++++++
> > >  1 file changed, 43 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/media/i2c/ov772x.yaml b/Documentation/devicetree/bindings/media/i2c/ov772x.yaml
> > > index 75dad40f70cc..3fad5dffd19a 100644
> > > --- a/Documentation/devicetree/bindings/media/i2c/ov772x.yaml
> > > +++ b/Documentation/devicetree/bindings/media/i2c/ov772x.yaml
> > > @@ -50,9 +50,47 @@ properties:
> > >            bus-type:
> > >              enum: [5, 6]
> > >
> > > +          bus-width:
> > > +            enum: [8, 10]
> > > +            default: 10
> > > +
> > > +          data-shift:
> > > +            enum: [0, 2]
> > > +            default: 0
> > > +
> > > +          hsync-active:
> > > +            enum: [0, 1]
> > > +            default: 1
> > > +
> > > +          vsync-active:
> > > +            enum: [0, 1]
> > > +            default: 1
> > > +
> > > +          pclk-sample:
> > > +            enum: [0, 1]
> > > +            default: 1
> > > +
> > >            remote-endpoint:
> > >              description: A phandle to the bus receiver's endpoint node.
> > >
> > > +        allOf:
> > > +          - if:
> > > +              properties:
> > > +                bus-type:
> > > +                  const: 6
> > > +            then:
> > > +                properties:
> > > +                  hsync-active: false
> > > +                  vsync-active: false
> > > +
> > > +          - if:
> > > +              properties:
> > > +                bus-width:
> > > +                  const: 10
> > > +            then:
> > > +                properties:
> > > +                  data-shift:
> > > +                    const: 0
> >
> > I'd add a blank line here.
> >
> > >          required:
> > >            - bus-type
> >
> > Should some of the properties be required ? Possibly conditioned on
> > bus-type ?
> >

I am not sure. They all have defaults, as reported here and as
supported by the driver. There's nothing -strictly- required, as long
as the here reported defaults are correct.

> Agreed, would be interesting to know how this can be handled (split
> out bus-type and add required properties for each) ?
>

That already happens with

+          - if:
+              properties:
+                bus-type:
+                  const: 6
+            then:
+                properties:
+                  hsync-active: false
+                  vsync-active: false

And could be expanded, if we want any of these to be required.

Thanks
  j

> Cheers,
> Prabhakar
>
> > >
> > > @@ -82,6 +120,11 @@ examples:
> > >              port {
> > >                  ov772x_0: endpoint {
> > >                      bus-type = <5>;
> > > +                    vsync-active = <0>;
> > > +                    hsync-active = <0>;
> > > +                    pclk-sample = <0>;
> > > +                    bus-width = <8>;
> > > +                    data-shift = <0>;
> > >                      remote-endpoint = <&vcap1_in0>;
> > >                  };
> > >              };
> >
> > --
> > Regards,
> >
> > Laurent Pinchart