refactor(usb): move usbconfig to a seperated package

internal/usbgadget/hid_mouse_relative.go

@@ -0,0 +1,92 @@
+package usbgadget
+
+import (
+	"fmt"
+	"os"
+)
+
+var relativeMouseConfig = gadgetConfigItem{
+	order:      1002,
+	device:     "hid.usb2",
+	path:       []string{"functions", "hid.usb2"},
+	configPath: []string{"hid.usb2"},
+	attrs: gadgetAttributes{
+		"protocol":      "2",
+		"subclass":      "1",
+		"report_length": "4",
+	},
+	reportDesc: relativeMouseCombinedReportDesc,
+}
+
+// from: https://github.com/NicoHood/HID/blob/b16be57caef4295c6cd382a7e4c64db5073647f7/src/SingleReport/BootMouse.cpp#L26
+var relativeMouseCombinedReportDesc = []byte{
+	0x05, 0x01, // USAGE_PAGE (Generic Desktop)	  54
+	0x09, 0x02, // USAGE (Mouse)
+	0xa1, 0x01, // COLLECTION (Application)
+
+	// Pointer and Physical are required by Apple Recovery
+	0x09, 0x01, // USAGE (Pointer)
+	0xa1, 0x00, // COLLECTION (Physical)
+
+	// 8 Buttons
+	0x05, 0x09, // USAGE_PAGE (Button)
+	0x19, 0x01, // USAGE_MINIMUM (Button 1)
+	0x29, 0x08, // USAGE_MAXIMUM (Button 8)
+	0x15, 0x00, // LOGICAL_MINIMUM (0)
+	0x25, 0x01, // LOGICAL_MAXIMUM (1)
+	0x95, 0x08, // REPORT_COUNT (8)
+	0x75, 0x01, // REPORT_SIZE (1)
+	0x81, 0x02, // INPUT (Data,Var,Abs)
+
+	// X, Y, Wheel
+	0x05, 0x01, // USAGE_PAGE (Generic Desktop)
+	0x09, 0x30, // USAGE (X)
+	0x09, 0x31, // USAGE (Y)
+	0x09, 0x38, // USAGE (Wheel)
+	0x15, 0x81, // LOGICAL_MINIMUM (-127)
+	0x25, 0x7f, // LOGICAL_MAXIMUM (127)
+	0x75, 0x08, // REPORT_SIZE (8)
+	0x95, 0x03, // REPORT_COUNT (3)
+	0x81, 0x06, // INPUT (Data,Var,Rel)
+
+	// End
+	0xc0, //       End Collection (Physical)
+	0xc0, //       End Collection
+}
+
+func (u *UsbGadget) relMouseWriteHidFile(data []byte) error {
+	if u.relMouseHidFile == nil {
+		var err error
+		u.relMouseHidFile, err = os.OpenFile("/dev/hidg2", os.O_RDWR, 0666)
+		if err != nil {
+			return fmt.Errorf("failed to open hidg1: %w", err)
+		}
+	}
+
+	_, err := u.relMouseHidFile.Write(data)
+	if err != nil {
+		u.log.Errorf("failed to write to hidg2: %w", err)
+		u.relMouseHidFile.Close()
+		u.relMouseHidFile = nil
+		return err
+	}
+	return nil
+}
+
+func (u *UsbGadget) RelMouseReport(mx, my int8, buttons uint8) error {
+	u.relMouseLock.Lock()
+	defer u.relMouseLock.Unlock()
+
+	err := u.relMouseWriteHidFile([]byte{
+		buttons,   // Buttons
+		uint8(mx), // X
+		uint8(my), // Y
+		0,         // Wheel
+	})
+	if err != nil {
+		return err
+	}
+
+	u.resetUserInputTime()
+	return nil
+}