dt-bindings: phy: qcom,sc8280xp-qmp-usb43dp-phy: Document lanes mapping when not using in USB-C complex

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.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20251119-topic-x1e80100-hdmi-v7-1-2bee0e66cc1b@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml

@@ -78,10 +78,77 @@ 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,
+                         The entry index is the DP lanes index, and the number is the PHY
+                         signal in the order RX0, TX0, TX1, RX1.
+            unevaluatedProperties: false
+
+            properties:
+              # Static lane mappings are mutually exclusive with typec-mux/orientation-mux
+              data-lanes:
+                $ref: /schemas/types.yaml#/definitions/uint32-array
+                minItems: 2
+                maxItems: 4
+                oneOf:
+                  - items: # DisplayPort 1 lane, normal orientation
+                      - const: 3
+                  - items: # DisplayPort 1 lane, flipped orientation
+                      - const: 0
+                  - items: # DisplayPort 2 lanes, normal orientation
+                      - const: 3
+                      - const: 2
+                  - items: # DisplayPort 2 lanes, flipped orientation
+                      - const: 0
+                      - const: 1
+                  - items: # DisplayPort 4 lanes, normal orientation
+                      - const: 3
+                      - const: 2
+                      - const: 1
+                      - const: 0
+                  - items: # DisplayPort 4 lanes, flipped orientation
+                      - const: 0
+                      - const: 1
+                      - const: 2
+                      - const: 3
+            required:
+              - data-lanes
+
+          endpoint@1:
+            $ref: /schemas/graph.yaml#/$defs/endpoint-base
+            description: USB Output lanes of the PHY when used with static mapping.
+                         The entry index is the USB3 lane in the order TX then RX, and the
+                         number is the PHY signal in the order RX0, TX0, TX1, RX1.
+            unevaluatedProperties: false
+
+            properties:
+              # Static lane mappings are mutually exclusive with typec-mux/orientation-mux
+              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