hid2hci

hid2hci [--mode=MODE] [--dev-id=DEV_ID] [--svid=SVID] [--spid=SPID] [--bus=BUS] [--dev=DEV]

--mode=MODE
    Set mode: hci (default, download firmware and switch to HCI alt interface) or vendor (keep HID interface).

--dev-id=DEV_ID
    Specify USB device ID in hex (e.g., 0x4106).

--svid=SVID
    USB vendor ID in hex (e.g., 0x0a5c for Broadcom).

--spid=SPID
    USB product ID in hex (e.g., 0x21e8).

--bus=BUS
    Target USB bus number (decimal).

--dev=DEV
    Target USB device number (decimal).

The hid2hci command is a utility designed to reprogram certain Broadcom Bluetooth chipsets that initially present as USB Human Interface Devices (HID), such as keyboards or mice, into standard Bluetooth Host Controller Interface (HCI) mode. This is essential for many laptop-embedded Bluetooth adapters or USB dongles from Broadcom (e.g., BCM20702, BCM43142) that ship in HID mode to comply with USB certification requirements.

It works by identifying the target device via USB bus, vendor ID (VID), product ID (PID), or device ID, then downloading the appropriate vendor-specific firmware and reconfiguring the USB alternate interface to HCI transport. Once switched, the Linux kernel's btusb driver can recognize and use it as a conventional Bluetooth adapter.

This tool is particularly useful during system boot or for live USB environments where Bluetooth isn't detected. It requires root privileges and is part of the BlueZ Bluetooth stack. Failure to switch correctly can render the device unusable until reboot or firmware reset.

Requires root privileges (sudo). Limited to Broadcom devices; check lsusb for VID:PID. Firmware download may fail on kernel >5.x without patches. Device resets on failure; reboot may restore HID mode.

Firmware files (BCMxxxx.hcd) must be in /lib/firmware/brcm/; install linux-firmware package.

Run lsusb | grep -i broadcom to find candidates (VID 0a5c).

Developed as part of BlueZ (Linux Bluetooth protocol stack) around 2010-2012 to address Broadcom USB BT chips stuck in HID mode. Integrated in BlueZ 5.x; usage peaked with older laptops (e.g., Lenovo, Dell). Modern kernels include auto-switching via btusb quirks, reducing reliance.

hciconfig(8), bluetoothctl(1), lsusb(8), usb_modeswitch(1)