dt-bindings: usb: Add Intel Keem Bay USB controller bindings

Binding description for Intel Keem Bay USB controller.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

Documentation/devicetree/bindings/usb/intel,keembay-dwc3.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/intel,keembay-dwc3.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Intel Keem Bay DWC3 USB controller
+
+maintainers:
+  - Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
+
+properties:
+  compatible:
+    const: intel,keembay-dwc3
+
+  clocks:
+    maxItems: 4
+
+  clock-names:
+    items:
+      - const: async_master
+      - const: ref
+      - const: alt_ref
+      - const: suspend
+
+  ranges: true
+
+  '#address-cells':
+    enum: [ 1, 2 ]
+
+  '#size-cells':
+    enum: [ 1, 2 ]
+
+# Required child node:
+
+patternProperties:
+  "^dwc3@[0-9a-f]+$":
+    type: object
+    description:
+      A child node must exist to represent the core DWC3 IP block.
+      The content of the node is defined in dwc3.txt.
+
+required:
+  - compatible
+  - clocks
+  - clock-names
+  - ranges
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #define KEEM_BAY_A53_AUX_USB
+    #define KEEM_BAY_A53_AUX_USB_REF
+    #define KEEM_BAY_A53_AUX_USB_ALT_REF
+    #define KEEM_BAY_A53_AUX_USB_SUSPEND
+
+    usb {
+          compatible = "intel,keembay-dwc3";
+          clocks = <&scmi_clk KEEM_BAY_A53_AUX_USB>,
+                   <&scmi_clk KEEM_BAY_A53_AUX_USB_REF>,
+                   <&scmi_clk KEEM_BAY_A53_AUX_USB_ALT_REF>,
+                   <&scmi_clk KEEM_BAY_A53_AUX_USB_SUSPEND>;
+          clock-names = "async_master", "ref", "alt_ref", "suspend";
+          ranges;
+          #address-cells = <1>;
+          #size-cells = <1>;
+
+          dwc3@34000000 {
+                compatible = "snps,dwc3";
+                reg = <0x34000000 0x10000>;
+                interrupts = <GIC_SPI 91 IRQ_TYPE_LEVEL_HIGH>;
+                dr_mode = "peripheral";
+          };
+    };