NETC is a multi-function PCIe Root Complex Integrated Endpoint (RCiEP)
that contains multiple PCIe functions, such as ENETC and Timer. Timer
provides PTP time synchronization functionality and ENETC provides the
NIC functionality.

For some platforms, such as i.MX95, it has only one timer instance, so
the binding relationship between Timer and ENETC is fixed. But for some
platforms, such as i.MX943, it has 3 Timer instances, by setting the
EaTBCR registers of the IERB module, we can specify any Timer instance
to be bound to the ENETC instance.

Therefore, add "nxp,netc-timer" property to bind ENETC instance to a
specified Timer instance so that ENETC can support PTP synchronization
through Timer.

Signed-off-by: Wei Fang <wei.fang@nxp.com>

---
v2 changes:
new patch
---
 .../devicetree/bindings/net/fsl,enetc.yaml    | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/fsl,enetc.yaml b/Documentation/devicetree/bindings/net/fsl,enetc.yaml
index ca70f0050171..ae05f2982653 100644
--- a/Documentation/devicetree/bindings/net/fsl,enetc.yaml
+++ b/Documentation/devicetree/bindings/net/fsl,enetc.yaml
@@ -44,6 +44,13 @@ properties:
     unevaluatedProperties: false
     description: Optional child node for ENETC instance, otherwise use NETC EMDIO.
 
+  nxp,netc-timer:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      Specifies a reference to a node representing a NETC Timer device,
+      which provides time synchronization as required for IEEE 1588 and
+      IEEE 802.1AS-2020.
+
 required:
   - compatible
   - reg
@@ -62,6 +69,7 @@ allOf:
       properties:
         clocks: false
         clock-names: false
+        nxp,netc-timer: false
 
 unevaluatedProperties: false
 
@@ -86,3 +94,18 @@ examples:
             };
         };
     };
+  - |
+    pcie {
+      #address-cells = <3>;
+      #size-cells = <2>;
+
+      ethernet@0,0 {
+          compatible = "pci1131,e101";
+          reg = <0x000000 0 0 0 0>;
+          clocks = <&scmi_clk 102>;
+          clock-names = "ref";
+          nxp,netc-timer = <&netc_timer>;
+          phy-handle = <&ethphy0>;
+          phy-mode = "rgmii-id";
+      };
+    };
-- 
2.34.1