Raspberry Pi 4のLinux ガジェットでマウスを実現する(USB OTG)

USAGE_PAGE (Generic Desktop)            05 01
USAGE (Mouse)                           09 02
    COLLECTION (Application)            A1 01
    USAGE (Pointer)                     09 01
    COLLECTION (Physical)               A1 00
        USAGE_PAGE (Button)             05 09
        USAGE_MINIMUM (Button 1)        19 01
        USAGE_MAXIMUM (Button 5)        29 05
        LOGICAL_MINIMUM (0)             15 00
        LOGICAL_MAXIMUM (1)             25 01
        REPORT_COUNT (5)                95 05
        REPORT_SIZE (1)                 75 01
        INPUT (Data,Var,Abs)            81 02
        REPORT_COUNT (1)                95 01
        REPORT_SIZE (3)                 75 03
        INPUT (Cnst,Var,Abs)            81 03
        USAGE_PAGE (Generic Desktop)    05 01
        USAGE (X)                       09 30
        USAGE (Y)                       09 31
        USAGE (Wheel)                   09 38
        LOGICAL_MINIMUM (-32767)        16 01 80
        LOGICAL_MAXIMUM (32767)         26 FF 7F
        REPORT_SIZE (16)                75 10
        REPORT_COUNT (3)                95 03
        INPUT (Data,Var,Rel)            81 06
    END_COLLECTION                      C0
END_COLLECTION                          C0

#!/bin/bash
GADGET="/sys/kernel/config/usb_gadget"
VID="0x1d6b"                        # Linux Foundation
PID="0x0104"                        # Multifunction Composite Gadget
DEVICE="0x0100"                     # v1.0.0
USB_TYPE="0x0200"                   # USB2
SERIAL_NUMBER="abcd1234"            # serial number
MANUFACTURER="toki-blog.com"        # manufacturer code
PRODUCT_NAME="Generic USB Mouse"    # product name
PROTOCOL="1"                        # USB protocol
SUBCLASS="1"                        # USB subclass
REPORT_LENGTH="7"                   # USB report length
REPORT_DESCRIPTOR="\\x05\\x01\\x09\\x02\\xA1\\x01\\x09\\x01\\xA1\\x00\\x05\\x09\\x19\\x01\\x29\\x05\\x15\\x00\\x25\\x01\\x95\\x05\\x75\\x01\\x81\\x02\\x95\\x01\\x75\\x03\\x81\\x03\\x05\\x01\\x09\\x30\\x09\\x31\\x09\\x38\\x16\\x01\\x80\\x26\\xFF\\x7F\\x75\\x10\\x95\\x03\\x81\\x06\\xC0\\xC0"
DEVICE_NO="usb0"
CONFIG_NO="1"
MAX_POWER="250"

case "$1" in
    start)
        echo "Creating the USB gadget"
        modprobe libcomposite       # Loading composite module

        echo "Creating gadget directory"
        cd $GADGET
        mkdir -p g1
        cd g1

        echo "Setting ID's"
        echo $VID > idVendor
        echo $PID > idProduct
        echo $DEVICE > bcdDevice
        echo $USB_TYPE > bcdUSB

        echo "Creating strings"
        mkdir -p strings/0x409
        echo $SERIAL_NUMBER > strings/0x409/serialnumber
        echo $MANUFACTURER > strings/0x409/manufacturer
        echo $PRODUCT_NAME > strings/0x409/product

        echo "Creating the functions"
        mkdir -p functions/hid.$DEVICE_NO
        echo $PROTOCOL > functions/hid.$DEVICE_NO/protocol
        echo $SUBCLASS > functions/hid.$DEVICE_NO/subclass
        echo $REPORT_LENGTH > functions/hid.$DEVICE_NO/report_length
        echo -ne $REPORT_DESCRIPTOR > functions/hid.$DEVICE_NO/report_desc

        echo "Creating the configurations"
        mkdir -p configs/c.$CONFIG_NO/strings/0x409
        echo "Config $CONFIG_NO: ECM network" > configs/c.$CONFIG_NO/strings/0x409/configuration
        echo $MAX_POWER > configs/c.$CONFIG_NO/MaxPower

        echo "Associating the functions with their configurations"
        ln -s functions/hid.$DEVICE_NO configs/c.$CONFIG_NO/

        echo "Enabling the USB gadget"
        ls /sys/class/udc > UDC
        echo "OK"
        
        ;;
    stop)
        echo "Stopping the USB gadget"

        echo "Disabling the USB gadget"
        cd $GADGET/g1
        echo "" > UDC

        echo "Cleaning up"
        rm configs/c.$CONFIG_NO/hid.$DEVICE_NO
        rmdir functions/hid.$DEVICE_NO

        echo "Cleaning up configuration"
        rmdir configs/c.$CONFIG_NO/strings/0x409
        rmdir configs/c.$CONFIG_NO

        echo "Clearing strings"
        rmdir strings/0x409

        echo "Removing gadget directory"
        cd $GADGET
        rmdir g1
        cd /

        # modprobe -r libcomposite    # Remove composite module
        echo "OK"

        ;;
    *)
        echo "Usage : $0 {start|stop}"
        ;;
esac

$ sudo su
# echo -ne "\x00\xff\x00\x00\x00\x00\x00" > /dev/hidg0

from enum import IntEnum

CLICK_OFF = 0x00        # Click off
CLICK_LEFT = 0x01       # 左クリック
CLICK_RIGHT = 0x02      # 右クリック
CLICK_MIDDLE = 0x04     # 真ん中クリック
CLICK_BACK = 0x08       # 戻る
CLICK_FORWARD = 0x10    # 進む

class MouseIndex(IntEnum):
    TIP_SW = 0
    X_LSB = 1
    X_MSB = 2
    Y_LSB = 3
    Y_MSB = 4
    WHEEL_LSB = 5
    WHEEL_MSB = 6
    MAX = 7

def send_command(buffer):
    cmd = bytes(buffer)
    with open('/dev/hidg0', 'rb+') as fd:
        fd.write(cmd)

def mouse_control(tip, x, y, wheel):
    data = [0] * MouseIndex.MAX
    data[MouseIndex.TIP_SW] = tip
    data[MouseIndex.X_LSB] = (x & 0xff)
    data[MouseIndex.X_MSB] = (x >> 8)
    data[MouseIndex.Y_LSB] = (y & 0xff)
    data[MouseIndex.Y_MSB] = (y >> 8)
    data[MouseIndex.WHEEL_LSB] = (wheel & 0xff)
    data[MouseIndex.WHEEL_MSB] = (wheel >> 8)
    send_command(data)

def main():
    print("Mouse sample.")

    x = 0
    y = 0
    wheel = 0
    # 左クリック
    mouse_control(CLICK_LEFT, x, y, wheel)
    mouse_control(CLICK_OFF, x, y, wheel)
    # カーソルX移動
    x = 100
    mouse_control(CLICK_OFF, x, y, wheel)

if __name__ == "__main__":
    main()