Generic Bluetooth controller over USB (btusb driver)
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Required properties:

  - compatible : should comply with the format "usbVID,PID" specified in
		 Documentation/devicetree/bindings/usb/usb-device.yaml
		 At the time of writing, the only OF supported devices
		 (more may be added later) are:

		  "usb1286,204e" (Marvell 8997)
		  "usbcf3,e300" (Qualcomm QCA6174A)
		  "usb4ca,301a" (Qualcomm QCA6174A (Lite-On))


Also, vendors that use btusb may have device additional properties, e.g:
Documentation/devicetree/bindings/net/bluetooth/marvell,sd8897-bt.yaml

Optional properties:

  - interrupt-names: (see below)
  - interrupts : The interrupt specified by the name "wakeup" is the interrupt
		 that shall be used for out-of-band wake-on-bt. Driver will
		 request this interrupt for wakeup. During system suspend, the
		 irq will be enabled so that the bluetooth chip can wakeup host
		 platform out of band. During system resume, the irq will be
		 disabled to make sure unnecessary interrupt is not received.

Example:

Following example uses irq pin number 3 of gpio0 for out of band wake-on-bt:

&usb_host1_ehci {
    #address-cells = <1>;
    #size-cells = <0>;

    mvl_bt1: bt@1 {
	compatible = "usb1286,204e";
	reg = <1>;
	interrupt-parent = <&gpio0>;
	interrupt-names = "wakeup";
	interrupts = <3 IRQ_TYPE_LEVEL_LOW>;
    };
};