Re: [PATCH v11 2/7] dt-bindings: media: qcom,x1e80100-camss: Add support for combo-mode endpoints

[Bryan O'Donoghue]

On 26/03/2026 01:51, Vladimir Zapolskiy wrote:
> On 3/26/26 03:28, Bryan O'Donoghue wrote:
> > Qualcomm CSI2 PHYs support a mode where two sensors may be attached to 
> > the
> > one CSIPHY.
> >
> > When we have one endpoint we may have
> > - DPHY 1, 2 or 4 data lanes + 1 clock lane
> > - CPHY 3 wire data lane
> >
> > When we have two endpoints this indicates the special fixed combo-mode.
> > - DPHY endpoint0 => 2+1 and endpoint1 => 1+1 data-lane/clock-lane 
> > combination.
> >
> > Reviewed-by: Christopher Obbard <christopher.obbard@xxxxxxxxxx>
> > Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
> > ---
> >   .../bindings/media/qcom,x1e80100-camss.yaml        | 69 ++++++++++++ 
> > ++++++++--
> >   1 file changed, 65 insertions(+), 4 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/media/qcom,x1e80100- 
> > camss.yaml b/Documentation/devicetree/bindings/media/qcom,x1e80100- 
> > camss.yaml
> > index c17b9757b2c86..f44138f522bba 100644
> > --- a/Documentation/devicetree/bindings/media/qcom,x1e80100-camss.yaml
> > +++ b/Documentation/devicetree/bindings/media/qcom,x1e80100-camss.yaml
> > @@ -148,7 +148,8 @@ properties:
> >       $ref: /schemas/graph.yaml#/properties/ports
> >       description:
> > -      CSI input ports.
> > +      CSI input ports. Supports either standard single sensor mode or
> > +      Qualcomm's combo mode with one sensor in 2x1 + 1x1 data-lane, 
> > clock-lane mode.
> >       patternProperties:
> >         "^port@[0-3]$":
> > @@ -156,26 +157,86 @@ properties:
> >           unevaluatedProperties: false
> >           description:
> > -          Input port for receiving CSI data from a CSIPHY.
> > +          Input port for receiving CSI data.
> >           properties:
> > -          endpoint:
> > +          endpoint@0:
> >               $ref: video-interfaces.yaml#
> >               unevaluatedProperties: false
> > +            description:
> > +              Endpoint for receiving a single sensor input (or first 
> > leg of combo).
> > +
> >               properties:
> >                 data-lanes:
> >                   minItems: 1
> > -                maxItems: 4
> > +                maxItems: 4 # Base max allows 4 (for D-PHY)
> > +
> > +              clock-lanes:
> > +                maxItems: 1
> >                 bus-type:
> >                   enum:
> >                     - 1 # MEDIA_BUS_TYPE_CSI2_CPHY
> >                     - 4 # MEDIA_BUS_TYPE_CSI2_DPHY
> > +          endpoint@1:
> > +            $ref: video-interfaces.yaml#
> > +            unevaluatedProperties: false
> > +
> > +            description:
> > +              Endpoint for receiving the second leg of a combo sensor 
> > input.
> > +
> > +            properties:
> > +              data-lanes:
> > +                maxItems: 1
> > +
> > +              clock-lanes:
> > +                maxItems: 1
> > +
> > +              bus-type:
> > +                const: 4 # Combo is D-PHY specific
> > +
>
> It's unclear why both 'bus-type' and 'phys' cell argument are needed
> at the same time, they are equal and thus one of two is redundant.

bus-type lives on the CAMSS controller endpoint. It tells the V4L2 
fwnode parser (v4l2_fwnode_endpoint_parse) how to interpret the endpoint 
properties — DPHY has data-lanes + clock-lanes, CPHY has trios.

PHY phandle cell lives on the phys reference. It tells the PHY driver 
which electrical mode to configure

---
bod