Linux USB Gadget - UAC & HID

usb-composite.sh

#!/bin/bash

modprobe libcomposite
mkdir -p /sys/kernel/config/usb_gadget/g
echo 0x1d6b > /sys/kernel/config/usb_gadget/g/idVendor  # Linux Foundation
echo 0x0104 > /sys/kernel/config/usb_gadget/g/idProduct # Multifunction Composite Gadget
echo 0x0100 > /sys/kernel/config/usb_gadget/g/bcdDevice # v1.0.0
echo 0x0200 > /sys/kernel/config/usb_gadget/g/bcdUSB    # USB 2.0
echo 0xef > /sys/kernel/config/usb_gadget/g/bDeviceClass    # USB 2.0
echo 0x02 > /sys/kernel/config/usb_gadget/g/bDeviceSubClass # USB 2.0
echo 0x01 > /sys/kernel/config/usb_gadget/g/bDeviceProtocol # USB 2.0
mkdir -p  /sys/kernel/config/usb_gadget/g/strings/0x409
echo "000001" > /sys/kernel/config/usb_gadget/g/strings/0x409/serialnumber
echo "VOICEN" > /sys/kernel/config/usb_gadget/g/strings/0x409/manufacturer
echo "devkit" > /sys/kernel/config/usb_gadget/g/strings/0x409/product

#mkdir -p /sys/kernel/config/usb_gadget/g/functions/acm.usb0    # serial

mkdir -p /sys/kernel/config/usb_gadget/g/functions/uac1.usb0   # audio

echo 0x1 > /sys/kernel/config/usb_gadget/g/functions/uac1.usb0/c_chmask
echo 48000 > /sys/kernel/config/usb_gadget/g/functions/uac1.usb0/c_srate
echo 0xf > /sys/kernel/config/usb_gadget/g/functions/uac1.usb0/p_chmask
echo 16000 > /sys/kernel/config/usb_gadget/g/functions/uac1.usb0/p_srate
mkdir -p /sys/kernel/config/usb_gadget/g/configs/c.1
echo 250 > /sys/kernel/config/usb_gadget/g/configs/c.1/MaxPower

mkdir -p /sys/kernel/config/usb_gadget/g/functions/hid.usb0   # hid

cd /sys/kernel/config/usb_gadget/g
echo 1 > functions/hid.usb0/protocol
echo 1 > functions/hid.usb0/subclass
echo 8 > functions/hid.usb0/report_length
echo -ne \\x05\\x01\\x09\\x06\\xa1\\x01\\x05\\x07\\x19\\xe0\\x29\\xe7\\x15\\x00\\x25\\x01\\x75\\x01\\x95\\x08\\x81\\x02\\x95\\x01\\x75\\x08\\x81\\x03\\x95\\x05\\x75\\x01\\x05\\x08\\x19\\x01\\x29\\x05\\x91\\x02\\x95\\x01\\x75\\x03\\x91\\x03\\x95\\x06\\x75\\x08\\x15\\x00\\x25\\x65\\x05\\x07\\x19\\x00\\x29\\x65\\x81\\x00\\xc0 > functions/hid.usb0/report_desc

ln -s /sys/kernel/config/usb_gadget/g/functions/uac1.usb0  /sys/kernel/config/usb_gadget/g/configs/c.1/
#ln -s /sys/kernel/config/usb_gadget/g/functions/acm.usb0  /sys/kernel/config/usb_gadget/g/configs/c.1/
ln -s /sys/kernel/config/usb_gadget/g/functions/hid.usb0  /sys/kernel/config/usb_gadget/g/configs/c.1/
udevadm settle -t 5 || :
ls /sys/class/udc/ > /sys/kernel/config/usb_gadget/g/UDC

Send A through HID:

sudo su
echo -ne "\0\0\x4\0\0\0\0\0" > /dev/hidg0 && echo -ne "\0\0\0\0\0\0\0\0" > /dev/hidg0

Send Caps:

echo -ne "\0\0\x39\0\0\0\0\0" > /dev/hidg0 && echo -ne "\0\0\0\0\0\0\0\0" > /dev/hidg0

A compatible issue on Windows 10

1. only enable UAC at first
2. disable USB
3. re-enable with UAC and HID

ls /sys/class/udc/ > /sys/kernel/config/usb_gadget/g/UDC
sleep 1
echo '' > /sys/kernel/config/usb_gadget/g/UDC
sleep 1
ln -s /sys/kernel/config/usb_gadget/g/functions/hid.usb0  /sys/kernel/config/usb_gadget/g/configs/c.1/
udevadm settle -t 5 || :
ls /sys/class/udc/ > /sys/kernel/config/usb_gadget/g/UDC