dt-bindings: usb: Convert xHCI bindings to DT schema

Currently the DT bindings of Generic xHCI Controllers are described by
means of the legacy text file. Since such format is deprecated in favor of
the DT schema, let's convert the Generic xHCI Controllers bindings file to
the corresponding yaml files. There will be two of them: a DT schema for
the xHCI controllers on a generic platform and a DT schema validating a
generic xHCI controllers properties. The later will be used to validate
the xHCI controllers, which aside from some vendor-specific features
support the basic xHCI functionality.

An xHCI-compatible DT node shall support the standard USB HCD properties
and custom ones like: usb2-lpm-disable, usb3-lpm-capable,
quirk-broken-port-ped and imod-interval-ns. In addition if a generic xHCI
controller is being validated against the DT schema it is also supposed to
be equipped with mandatory compatible string, single registers range,
single interrupts source, and is supposed to optionally contain up to two
reference clocks for the controller core and CSRs.

Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Serge Semin <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/usb/generic-xhci.yaml

···
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/generic-xhci.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: USB xHCI Controller Device Tree Bindings
+
+maintainers:
+  - Mathias Nyman <[e-mail]>
+
+allOf:
+  - $ref: "usb-xhci.yaml#"
+
+properties:
+  compatible:
+    oneOf:
+      - description: Generic xHCI device
+        const: generic-xhci
+      - description: Armada 37xx/375/38x/8k SoCs
+        items:
+          - enum:
+              - marvell,armada3700-xhci
+              - marvell,armada-375-xhci
+              - marvell,armada-380-xhci
+              - marvell,armada-8k-xhci
+          - const: generic-xhci
+      - description: Broadcom STB SoCs with xHCI
+        const: brcm,bcm7445-xhci
+      - description: Generic xHCI device
+        const: xhci-platform
+        deprecated: true
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    minItems: 1
+    maxItems: 2
+
+  clock-names:
+    minItems: 1
+    items:
+      - const: core
+      - const: reg
+
+unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+examples:
+  - |
+    usb@f0931000 {
+      compatible = "generic-xhci";
+      reg = <0xf0931000 0x8c8>;
+      interrupts = <0x0 0x4e 0x0>;
+    };

Documentation/devicetree/bindings/usb/usb-xhci.txt

···
-USB xHCI controllers
-
-Required properties:
-  - compatible: should be one or more of
-
-    - "generic-xhci" for generic XHCI device
-    - "marvell,armada3700-xhci" for Armada 37xx SoCs
-    - "marvell,armada-375-xhci" for Armada 375 SoCs
-    - "marvell,armada-380-xhci" for Armada 38x SoCs
-    - "brcm,bcm7445-xhci" for Broadcom STB SoCs with XHCI
-    - "xhci-platform" (deprecated)
-
-    When compatible with the generic version, nodes must list the
-    SoC-specific version corresponding to the platform first
-    followed by the generic version.
-
-  - reg: should contain address and length of the standard XHCI
-    register set for the device.
-  - interrupts: one XHCI interrupt should be described here.
-
-Optional properties:
-  - clocks: reference to the clocks
-  - clock-names: mandatory if there is a second clock, in this case
-    the name must be "core" for the first clock and "reg" for the
-    second one
-  - usb2-lpm-disable: indicate if we don't want to enable USB2 HW LPM
-  - usb3-lpm-capable: determines if platform is USB3 LPM capable
-  - quirk-broken-port-ped: set if the controller has broken port disable mechanism
-  - imod-interval-ns: default interrupt moderation interval is 5000ns
-  - phys : see usb-hcd.yaml in the current directory
-
-additionally the properties from usb-hcd.yaml (in the current directory) are
-supported.
-
-
-Example:
-	usb@f0931000 {
-		compatible = "generic-xhci";
-		reg = <0xf0931000 0x8c8>;
-		interrupts = <0x0 0x4e 0x0>;
-	};

Documentation/devicetree/bindings/usb/usb-xhci.yaml

···
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/usb-xhci.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic USB xHCI Controller Device Tree Bindings
+
+maintainers:
+  - Mathias Nyman <[e-mail]>
+
+allOf:
+  - $ref: "usb-hcd.yaml#"
+
+properties:
+  usb2-lpm-disable:
+    description: Indicates if we don't want to enable USB2 HW LPM
+    type: boolean
+
+  usb3-lpm-capable:
+    description: Determines if platform is USB3 LPM capable
+    type: boolean
+
+  quirk-broken-port-ped:
+    description: Set if the controller has broken port disable mechanism
+    type: boolean
+
+  imod-interval-ns:
+    description: Interrupt moderation interval
+    default: 5000
+
+additionalProperties: true
+
+examples:
+  - |
+    usb@f0930000 {
+      compatible = "generic-xhci";
+      reg = <0xf0930000 0x8c8>;
+      interrupts = <0x0 0x4e 0x0>;
+      usb2-lpm-disable;
+      usb3-lpm-capable;
+    };