dt-bindings: usb: cdns3: Add cdns,cdnsp compatible string

Introduce a new generic fallback compatible string 'cdns,cdnsp' for
Cadence USBSSP controllers to support hardware configurations where
the Dual-Role Device (DRD) register block is missing or inaccessible.

Following the maintainer's feedback, avoid generic property-like naming
(such as "-no-drd") and use a clean generic fallback. To keep the schema
resource-driven and strictly validated, define a two-string compatible
matrix using an empty schema ({}) wildcard. This allows future vendor
SoC compatibles to be prepended while safely falling back to the 2-resource
USBSSP configuration.

When 'cdns,cdnsp' is matched:
- The 'otg' register and interrupt resources are not required.
- The 'reg' and 'interrupts' properties are restricted to 2 items
  (host and device).
- 'dr_mode' must be explicitly set to either 'host' or 'peripheral'.

The standard 'cdns,usb3' compatible remains unchanged, maintaining
backward compatibility by requiring all 3 resource sets (otg, host, dev).

Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20260521-no_drd_config_v9-v9-1-2512cef10104@cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/devicetree/bindings/usb/cdns,usb3.yaml b/Documentation/devicetree/bindings/usb/cdns,usb3.yaml
index 2d95fb7321affc52664664bb18c57ca2e8c6fc1a..e8082c5c05a2582bd7b706c2c702a468e2b76583 100644 (file)
--- a/Documentation/devicetree/bindings/usb/cdns,usb3.yaml
+++ b/Documentation/devicetree/bindings/usb/cdns,usb3.yaml
@@ -17,22 +17,24 @@ description:
 
 properties:
   compatible:
-    const: cdns,usb3
+    oneOf:
+      - const: cdns,usb3
+      - items:
+          - {}
+          - const: cdns,cdnsp
 
   reg:
-    items:
-      - description: OTG controller registers
-      - description: XHCI Host controller registers
-      - description: DEVICE controller registers
+    minItems: 2
+    maxItems: 3
 
   reg-names:
+    minItems: 2
+    maxItems: 3
     items:
-      - const: otg
-      - const: xhci
-      - const: dev
+      enum: [ otg, xhci, dev ]
 
   interrupts:
-    minItems: 3
+    minItems: 2
     items:
       - description: XHCI host controller interrupt
       - description: Device controller interrupt
@@ -41,7 +43,7 @@ properties:
                      cleared by xhci core, this interrupt is optional
 
   interrupt-names:
-    minItems: 3
+    minItems: 2
     items:
       - const: host
       - const: peripheral
@@ -93,6 +95,47 @@ allOf:
   - $ref: usb-drd.yaml#
   - $ref: usb-xhci.yaml#
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: cdns,cdnsp
+    then:
+      properties:
+        reg:
+          items:
+            - description: XHCI Host controller registers
+            - description: DEVICE controller registers
+        reg-names:
+          items:
+            - const: xhci
+            - const: dev
+        interrupts:
+          maxItems: 2
+        interrupt-names:
+          items:
+            - const: host
+            - const: peripheral
+        dr_mode:
+          enum: [host, peripheral]
+    else:
+      properties:
+        reg:
+          items:
+            - description: OTG controller registers
+            - description: XHCI Host controller registers
+            - description: DEVICE controller registers
+        reg-names:
+          items:
+            - const: otg
+            - const: xhci
+            - const: dev
+        interrupts:
+          minItems: 3
+          maxItems: 4
+        interrupt-names:
+          minItems: 3
+
 unevaluatedProperties: false
 
 examples: