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

[Bryan O'Donoghue <bryan.odonoghue@linaro.org>]

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@linaro.org>
>> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
>> ---
>>   .../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