Re: [PATCH v3 3/5] dt-bindings: phy: qcom,sc8280xp-qmp-usb43dp-phy: Document lanes mapping when not using in USB-C complex

[Neil Armstrong <neil.armstrong@linaro.org>]

On 08/09/2025 23:14, Dmitry Baryshkov wrote:
> On Mon, Sep 08, 2025 at 03:04:20PM +0200, Neil Armstrong wrote:
>> The QMP USB3/DP Combo PHY hosts an USB3 phy and a DP PHY on top
>> of a combo glue to route either lanes to the 4 shared physical lanes.
>>
>> The routing of the lanes can be:
>> - 2 DP + 2 USB3
>> - 4 DP
>> - 2 USB3
>>
>> The layout of the lanes was designed to be mapped and swapped
>> related to the USB-C Power Delivery negociation, so it supports
>> a finite set of mappings inherited by the USB-C Altmode layouts.
>>
>> Nevertheless those QMP Comby PHY can be used to drive a DisplayPort
>> connector, DP->HDMI bridge, USB3 A Connector, etc... without
>> an USB-C connector and no PD events.
>>
>> Document the data-lanes on numbered port@0 out endpoints,
>> allowing us to document the lanes mapping to DisplayPort
>> and/or USB3 connectors/peripherals.
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   .../phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml         | 59 +++++++++++++++++++++-
>>   1 file changed, 58 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
>> index 5005514d7c3a1e4a8893883497fd204bc04e12be..51e0d0983091af0b8a5170ac34a05ab0acc435a3 100644
>> --- a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
>> +++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
>> @@ -81,10 +81,67 @@ properties:
>>   
>>     ports:
>>       $ref: /schemas/graph.yaml#/properties/ports
>> +
>>       properties:
>>         port@0:
>> -        $ref: /schemas/graph.yaml#/properties/port
>> +        $ref: /schemas/graph.yaml#/$defs/port-base
>>           description: Output endpoint of the PHY
>> +        unevaluatedProperties: false
>> +
>> +        properties:
>> +          endpoint:
>> +            $ref: /schemas/graph.yaml#/$defs/endpoint-base
>> +            unevaluatedProperties: false
>> +
>> +          endpoint@0:
>> +            $ref: /schemas/graph.yaml#/$defs/endpoint-base
>> +            description: Display Port Output lanes of the PHY when used with static mapping
>> +            unevaluatedProperties: false
>> +
>> +            properties:
>> +              data-lanes:
>> +                $ref: /schemas/types.yaml#/definitions/uint32-array
>> +                minItems: 2
> 
> Nit: DP can work in a 1-lane mode. Do we nned to support that in the PHY?

So the PHY already supports 1-lane, but the QMP Combo only supports
mapping 2+2 or 4, but nevetheless we can still decscribe 1 lane in DT
int both in & out endpoint and still should work fine.

Do you think this should be done now ?

Neil

> 
>> +                maxItems: 4
>> +                oneOf:
>> +                  - items: # DisplayPort 2 lanes, normal orientation
>> +                      - const: 0
>> +                      - const: 1
>> +                  - items: # DisplayPort 2 lanes, flipped orientation
>> +                      - const: 3
>> +                      - const: 2
>> +                  - items: # DisplayPort 4 lanes, normal orientation
>> +                      - const: 0
>> +                      - const: 1
>> +                      - const: 2
>> +                      - const: 3
>> +                  - items: # DisplayPort 4 lanes, flipped orientation
>> +                      - const: 3
>> +                      - const: 2
>> +                      - const: 1
>> +                      - const: 0
>> +            required:
>> +              - data-lanes
>> +
>> +          endpoint@1:
>> +            $ref: /schemas/graph.yaml#/$defs/endpoint-base
>> +            description: USB Output lanes of the PHY when used with static mapping
>> +            unevaluatedProperties: false
>> +
>> +            properties:
>> +              data-lanes:
>> +                $ref: /schemas/types.yaml#/definitions/uint32-array
>> +                minItems: 2
>> +                oneOf:
>> +                  - items: # USB3, normal orientation
>> +                      - const: 1
>> +                      - const: 0
>> +                  - items: # USB3, flipped orientation
>> +                      - const: 2
>> +                      - const: 3
>> +
>> +            required:
>> +              - data-lanes
>>   
>>         port@1:
>>           $ref: /schemas/graph.yaml#/properties/port
>>
>> -- 
>> 2.34.1
>>
>