[PATCH net-next 1/2] dt-bindings: net: Add Sophgo CV1800 MDIO multiplexer

[Inochi Amaoto]

The Sophgo CV1800 uses an internal MDIO bus multiplexer to handle the
internal phy and external phy. The internal phy is always on MDIO bus
address 0, and the external bus can be configured with different MDIO
address.

Add documentation and compatible string for the MDIO multiplexer on
CV1800 Series SoC.

Signed-off-by: Inochi Amaoto <inochiama at gmail.com>
---
 .../bindings/net/sophgo,cv1800b-mdio-mux.yaml | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/sophgo,cv1800b-mdio-mux.yaml

diff --git a/Documentation/devicetree/bindings/net/sophgo,cv1800b-mdio-mux.yaml b/Documentation/devicetree/bindings/net/sophgo,cv1800b-mdio-mux.yaml
new file mode 100644
index 000000000000..abe0004c8b6e
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/sophgo,cv1800b-mdio-mux.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/sophgo,cv1800b-mdio-mux.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sophgo CV1800B MDIO bus multiplexer
+
+maintainers:
+  - Inochi Amaoto <inochiama at gmail.com>
+
+description:
+  This MDIO bus multiplexer defines buses that could be internal as well as
+  external to SoCs. The external mdio bus can be configured at different
+  bus address.
+
+allOf:
+  - $ref: mdio-mux.yaml#
+
+properties:
+  compatible:
+    const: sophgo,cv1800b-mdio-mux
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    mdio at 3009000 {
+      compatible = "sophgo,cv1800b-mdio-mux";
+      reg = <0x3009000 0x1000>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+      mdio-parent-bus = <&gmac0_mdio>;
+
+      mdio at 0 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        reg = <0>;
+      };
+    };
-- 
2.49.0