[net-next 8/9] dt-bindings: net: renesas,etheravb: Add optional gPTP phandle for Gen4

[Niklas Söderlund]

The RAVB module on Gen4 have no gPTP clock as part of the RAVB module
itself, instead it relies on an external system wide gPTP clock. The
gPTP clock is shared with RTSN on V4H and RSWITCH on S4.

Add an optional phandle so that the RAVB driver can find and use the
gPTP clock. Ideally this should have been an mandatory property but for
backward compatible it is optional. The RAVB module is capable of
functioning without it, but can in such cases not provided PTP
functionality.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
---
 .../bindings/net/renesas,etheravb.yaml           | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/renesas,etheravb.yaml b/Documentation/devicetree/bindings/net/renesas,etheravb.yaml
index 1e00ef5b3acd..7bc910ab3ae0 100644
--- a/Documentation/devicetree/bindings/net/renesas,etheravb.yaml
+++ b/Documentation/devicetree/bindings/net/renesas,etheravb.yaml
@@ -122,6 +122,13 @@ properties:
       Specify when the AVB_LINK signal is active-low instead of normal
       active-high.
 
+  renesas,gptp:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      A phandle to an external gPTP clock for Gen4 platforms. The property is
+      optional for backwards compatibility, but without it gPTP timestamps are
+      disabled as Gen4 have no gPTP as part of the RAVB module itself.
+
   rx-internal-delay-ps:
     enum: [0, 1800]
 
@@ -305,6 +312,15 @@ allOf:
             items:
               - const: fck
               - const: refclk
+  - if:
+      not:
+        properties:
+          compatible:
+            contains:
+              const: renesas,etheravb-rcar-gen4
+    then:
+      properties:
+        renesas,gptp: false
 
 additionalProperties: false
 
-- 
2.54.0