dt-bindings: net: Convert mdio-gpio to yaml

Converts net/mdio-gpio.txt to yaml

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Link: https://lore.kernel.org/r/20210505202815.2665920-1-clabbe@baylibre.com
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/net/mdio-gpio.yaml

@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/mdio-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MDIO on GPIOs
+
+maintainers:
+  - Andrew Lunn <andrew@lunn.ch>
+  - Heiner Kallweit <hkallweit1@gmail.com>
+  - Russell King <linux@armlinux.org.uk>
+
+allOf:
+  - $ref: "mdio.yaml#"
+
+properties:
+  compatible:
+    enum:
+      - virtual,mdio-gpio
+      - microchip,mdio-smi0
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  gpios:
+    minItems: 2
+    maxItems: 3
+    items:
+      - description: MDC
+      - description: MDIO
+      - description: MDO
+
+#Note: Each gpio-mdio bus should have an alias correctly numbered in "aliases"
+#node.
+additionalProperties:
+  type: object
+
+examples:
+  - |
+    aliases {
+        mdio-gpio0 = &mdio0;
+    };
+
+    mdio0: mdio {
+      compatible = "virtual,mdio-gpio";
+      #address-cells = <1>;
+      #size-cells = <0>;
+      gpios = <&qe_pio_a 11>,
+              <&qe_pio_c 6>;
+      ethphy0: ethernet-phy@0 {
+        reg = <0>;
+      };
+    };
+...