You will need this identifier such as 0a5c:21e6, shown above. See this wiki entry for more information on identifying USB devices. Or Bus 004 Device 006: ID 0a5c:21e3 Broadcom Corp. Your Bluetooth card will likely be on the USB bus, for example: Bus 003 Device 016: ID 0a5c:21e6 Broadcom Corp.

Your bluetooth adapter, while on the same card as your wifi will have a seperate hardware ID. You will need to identify both your Hardware ID and the name of the missing Firmware file.