samd21,samd51,nrf52840: refactor handleStandardSetup and initEndpoint (#2968)

* samd21,samd51,nrf52840: refactor handleStandardSetup and initEndpoint

src/machine/usb.go

@@ -324,6 +324,83 @@ func sendDescriptor(setup USBSetup) {
 	return
 }
 
+func handleStandardSetup(setup USBSetup) bool {
+	switch setup.BRequest {
+	case usb_GET_STATUS:
+		buf := []byte{0, 0}
+
+		if setup.BmRequestType != 0 { // endpoint
+			if isEndpointHalt {
+				buf[0] = 1
+			}
+		}
+
+		sendUSBPacket(0, buf, setup.WLength)
+		return true
+
+	case usb_CLEAR_FEATURE:
+		if setup.WValueL == 1 { // DEVICEREMOTEWAKEUP
+			isRemoteWakeUpEnabled = false
+		} else if setup.WValueL == 0 { // ENDPOINTHALT
+			isEndpointHalt = false
+		}
+		SendZlp()
+		return true
+
+	case usb_SET_FEATURE:
+		if setup.WValueL == 1 { // DEVICEREMOTEWAKEUP
+			isRemoteWakeUpEnabled = true
+		} else if setup.WValueL == 0 { // ENDPOINTHALT
+			isEndpointHalt = true
+		}
+		SendZlp()
+		return true
+
+	case usb_SET_ADDRESS:
+		return handleUSBSetAddress(setup)
+
+	case usb_GET_DESCRIPTOR:
+		sendDescriptor(setup)
+		return true
+
+	case usb_SET_DESCRIPTOR:
+		return false
+
+	case usb_GET_CONFIGURATION:
+		buff := []byte{usbConfiguration}
+		sendUSBPacket(0, buff, setup.WLength)
+		return true
+
+	case usb_SET_CONFIGURATION:
+		if setup.BmRequestType&usb_REQUEST_RECIPIENT == usb_REQUEST_DEVICE {
+			for i := 1; i < len(endPoints); i++ {
+				initEndpoint(uint32(i), endPoints[i])
+			}
+
+			usbConfiguration = setup.WValueL
+
+			SendZlp()
+			return true
+		} else {
+			return false
+		}
+
+	case usb_GET_INTERFACE:
+		buff := []byte{usbSetInterface}
+		sendUSBPacket(0, buff, setup.WLength)
+		return true
+
+	case usb_SET_INTERFACE:
+		usbSetInterface = setup.WValueL
+
+		SendZlp()
+		return true
+
+	default:
+		return true
+	}
+}
+
 // EnableHID enables HID. This function must be executed from the init().
 func EnableHID(callback func()) {
 	usbDescriptor = descriptorCDCHID