Re: [PATCH v3 2/2] dt-bindings: media: Use graph and video-interfaces schemas

From: Laurent Pinchart
Date: Wed Dec 16 2020 - 12:45:06 EST


Hi Rob,

On Wed, Dec 16, 2020 at 11:38:41AM -0600, Rob Herring wrote:
> On Wed, Dec 16, 2020 at 05:19:55PM +0200, Laurent Pinchart wrote:
> > On Thu, Dec 10, 2020 at 03:16:25PM -0600, Rob Herring wrote:
> > > Now that we have graph and video-interfaces schemas, rework the media
> > > related schemas to use them.
> > >
> > > Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> > > Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
> > > Cc: Jacopo Mondi <jacopo@xxxxxxxxxx>
> > > Cc: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> > > Cc: linux-media@xxxxxxxxxxxxxxx
> > > Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> > > ---
>
>
> > > diff --git a/Documentation/devicetree/bindings/media/i2c/mipi-ccs.yaml b/Documentation/devicetree/bindings/media/i2c/mipi-ccs.yaml
> > > index d94bd67ccea1..3657f2f41098 100644
> > > --- a/Documentation/devicetree/bindings/media/i2c/mipi-ccs.yaml
> > > +++ b/Documentation/devicetree/bindings/media/i2c/mipi-ccs.yaml
> > > @@ -73,19 +73,16 @@ properties:
> > > enum: [ 0, 180 ]
> > >
> > > port:
> > > - type: object
> > > + $ref: /schemas/graph.yaml#/$defs/port-base
> > > + additionalProperties: false
> > > +
> > > properties:
> > > endpoint:
> > > - type: object
> > > + $ref: /schemas/media/video-interfaces.yaml#
> > > + unevaluatedProperties: false
> > > +
> > > properties:
> > > - link-frequencies:
> > > - $ref: /schemas/types.yaml#/definitions/uint64-array
> > > - description: List of allowed data link frequencies.
> > > - data-lanes:
> > > - minItems: 1
> > > - maxItems: 8
> >
> > Don't we need
> >
> > link-frequencies: true
> > data-lanes: true
> >
> > to convey the fact that those properties are applicable for this device
> > ? This applies to a few locations below too.
>
> Adding them would convey that to the reader, but wouldn't change the
> schema validation. We'd have to use 'additionalProperties' instead and
> also add 'remote-endpoint' everywhere (and 'reg' sometimes). I prefer
> not doing all that, but if we want it just for purposes of documenting
> the usage, that's fine.

I'd prefer keeping it to document what properties are applicable. If we
can later find a better way to express it in a way that will be taken
into account during validation, that will be best, but not required now.

> > > bus-type:
> > > - description: The type of the data bus.
> > > oneOf:
> > > - const: 1 # CSI-2 C-PHY
> > > - const: 3 # CCP2
> > > diff --git a/Documentation/devicetree/bindings/media/i2c/ov5647.yaml b/Documentation/devicetree/bindings/media/i2c/ov5647.yaml
> > > index 280c62afae13..3b1ea9da437a 100644
> > > --- a/Documentation/devicetree/bindings/media/i2c/ov5647.yaml
> > > +++ b/Documentation/devicetree/bindings/media/i2c/ov5647.yaml
> > > @@ -31,27 +31,15 @@ properties:
> > > maxItems: 1
> > >
> > > port:
> > > - type: object
> > > - description: |-
> > > - Should contain one endpoint sub-node used to model connection to the
> > > - video receiver according to the specification defined in
> > > - Documentation/devicetree/bindings/media/video-interfaces.txt.
> > > + $ref: /schemas/graph.yaml#/$defs/port-base
> > >
> > > properties:
> > > endpoint:
> > > - type: object
> > > + $ref: /schemas/media/video-interfaces.yaml#
> > > + unevaluatedProperties: false
> > >
> > > properties:
> > > - remote-endpoint:
> > > - description: |-
> > > - phandle to the video receiver input port.
> > > -
> > > - clock-noncontinuous:
> > > - type: boolean
> > > - description: |-
> > > - Set to true to allow MIPI CSI-2 non-continuous clock operations.
> > > -
> > > - additionalProperties: false
> > > + clock-noncontinuous: true
> > >
> > > additionalProperties: false
> > >
> > > diff --git a/Documentation/devicetree/bindings/media/i2c/ov8856.yaml b/Documentation/devicetree/bindings/media/i2c/ov8856.yaml
> > > index cde85553fd01..c29b057ae922 100644
> > > --- a/Documentation/devicetree/bindings/media/i2c/ov8856.yaml
> > > +++ b/Documentation/devicetree/bindings/media/i2c/ov8856.yaml
> > > @@ -57,16 +57,13 @@ properties:
> > > active low.
> > >
> > > port:
> > > - type: object
> > > + $ref: /schemas/graph.yaml#/$defs/port-base
> > > additionalProperties: false
> > > - description:
> > > - A node containing an output port node with an endpoint definition
> > > - as documented in
> > > - Documentation/devicetree/bindings/media/video-interfaces.txt
> > >
> > > properties:
> > > endpoint:
> > > - type: object
> > > + $ref: /schemas/media/video-interfaces.yaml#
> > > + unevaluatedProperties: false
> > >
> > > properties:
> > > data-lanes:
> > > @@ -79,18 +76,13 @@ properties:
> > > - const: 4
> > >
> > > link-frequencies:
> > > - $ref: /schemas/types.yaml#/definitions/uint64-array
> > > - description:
> > > - Allowed data bus frequencies. 360000000, 180000000 Hz or both
> > > - are supported by the driver.
> > > -
> > > + maxItems: 2
> > > + items:
> > > + enum: [ 360000000, 180000000 ]
> >
> > This is a limitation of the driver, not the device. Should we keep this
> > information in a comment, to eventually get it fixed and drop the
> > limitation from the bindings ?
>
> If your dts has anything else, then it won't work. Warning on that seems
> valuable to me, so I think we should keep it. If someone with a better
> driver complains, we can drop it.
>
> I can keep the description with 'Frequencies listed are driver, not h/w
> limitations'.

I'm fine with the constraint itself, my comment was referring to the
fact that we're dropping the description. Your description proposal
works for me, thanks.

--
Regards,

Laurent Pinchart