[PATCH v3 1/5] dt-bindings: phy: rockchip: rk3399-typec-phy: Support mode-switch

[Chaoyi Chen]

From: Chaoyi Chen <chaoyi.chen@xxxxxxxxxxxxxx>

The RK3399 SoC integrates two USB/DP combo PHYs, each of which
supports software-configurable pin mapping and DisplayPort lane
assignment. These capabilities enable the PHY itself to handle both
mode switching and orientation switching, based on the Type-C plug
orientation and USB PD negotiation results.

While an external Type-C controller is still required to detect cable
attachment and report USB PD events, the actual mode and orientation
switching is performed internally by the PHY through software
configuration. This allows the PHY to act as a Type-C multiplexer for
both data role and DP altmode configuration.

To reflect this hardware design, this patch introduces a new
"mode-switch" property for the dp-port node in the device tree bindings.
This property indicates that the connected PHY is capable of handling
Type-C mode switching itself.

Signed-off-by: Chaoyi Chen <chaoyi.chen@xxxxxxxxxxxxxx>
---

Changes in v3:
- Add more descriptions to clarify the role of the PHY in switching.

Changes in v2:
- Reuse dp-port/usb3-port in rk3399-typec-phy binding.

 .../devicetree/bindings/phy/rockchip,rk3399-typec-phy.yaml  | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/phy/rockchip,rk3399-typec-phy.yaml b/Documentation/devicetree/bindings/phy/rockchip,rk3399-typec-phy.yaml
index 91c011f68cd0..ccbe1c9cb0bf 100644
--- a/Documentation/devicetree/bindings/phy/rockchip,rk3399-typec-phy.yaml
+++ b/Documentation/devicetree/bindings/phy/rockchip,rk3399-typec-phy.yaml
@@ -51,6 +51,12 @@ properties:
       '#phy-cells':
         const: 0
 
+      mode-switch:
+        description: |
+          Indicates the PHY can handle altmode switching. In this case,
+          requires an external USB Type-C controller to report USB PD message.
+        type: boolean
+
       port:
         $ref: /schemas/graph.yaml#/properties/port
         description: Connection to USB Type-C connector
-- 
2.49.0