dt-bindings: phy: meson8b-usb2: Convert to json-schema

Now that we have the DT validation in place, let's convert the device
tree bindings for the Amlogic Meson8, Meson8b, Meson8m2 and GXBB USB2
PHY over to a YAML schema.

While here, also add the fallback compatible string
"amlogic,meson-gxbb-usb2-phy" which is already used in
arch/arm/boot/dts/meson{,8,8b}.dtsi.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Thomas Graichen <thomas.graichen@gmail.com>
Link: https://lore.kernel.org/r/20200512222424.549351-2-martin.blumenstingl@googlemail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/amlogic,meson8b-usb2-phy.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/phy/amlogic,meson8b-usb2-phy.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Amlogic Meson8, Meson8b, Meson8m2 and GXBB USB2 PHY
+
+maintainers:
+  - Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - amlogic,meson8-usb2-phy
+              - amlogic,meson8b-usb2-phy
+          - const: amlogic,meson-mx-usb2-phy
+      - const: amlogic,meson-gxbb-usb2-phy
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    minItems: 2
+
+  clock-names:
+    items:
+      - const: usb_general
+      - const: usb
+
+  resets:
+    minItems: 1
+
+  "#phy-cells":
+    const: 0
+
+  phy-supply:
+    description:
+      Phandle to a regulator that provides power to the PHY. This
+      regulator will be managed during the PHY power on/off sequence.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    usb-phy@c0000000 {
+      compatible = "amlogic,meson-gxbb-usb2-phy";
+      reg = <0xc0000000 0x20>;
+      resets = <&reset_usb_phy>;
+      clocks = <&clk_usb_general>, <&reset_usb>;
+      clock-names = "usb_general", "usb";
+      phy-supply = <&usb_vbus>;
+      #phy-cells = <0>;
+    };

Documentation/devicetree/bindings/phy/meson8b-usb2-phy.txt

-* Amlogic Meson8, Meson8b and GXBB USB2 PHY
-
-Required properties:
-- compatible:	Depending on the platform this should be one of:
-	"amlogic,meson8-usb2-phy"
-	"amlogic,meson8b-usb2-phy"
-	"amlogic,meson-gxbb-usb2-phy"
-- reg:		The base address and length of the registers
-- #phys-cells:	should be 0 (see phy-bindings.txt in this directory)
-- clocks:	phandle and clock identifier for the phy clocks
-- clock-names:	"usb_general" and "usb"
-
-Optional properties:
-- resets:	reference to the reset controller
-- phy-supply:	see phy-bindings.txt in this directory
-
-
-Example:
-
-usb0_phy: usb-phy@c0000000 {
-	compatible = "amlogic,meson-gxbb-usb2-phy";
-	#phy-cells = <0>;
-	reg = <0x0 0xc0000000 0x0 0x20>;
-	resets = <&reset RESET_USB_OTG>;
-	clocks = <&clkc CLKID_USB>, <&clkc CLKID_USB0>;
-	clock-names = "usb_general", "usb";
-	phy-supply = <&usb_vbus>;
-};