The DMX USB driver is a Linux 2.6 kernel driver for the Enttec
DMX USB dongle ( http://www.enttec.com/dmxusb.php )

Building the driver

Before the driver can be build, the kernel sourcecode needs to be 
installed. To build the driver just call make, this should build a
dmx_usb.ko (the kernel module) and a dmx_usb_test(a small test
program).

Loading the right driver.

A "small" problem to solve was to make the kernel clear that it should 
use my driver for the dongle and not the standard usbserial driver. 
Since I don't have any other USBserial devices with the samechip type I 
just removed the ftdi_sio.ko module, and changed the /etc/hotplug/usb.distmap 
to point to my module. To support both the ftdi_sio.o module and the 
dmx_usb.o module the ftdi_sio.o module should be patched and the Product ID 
for the FT232BM should be removed from it, this will mean all other 
serial-usb devices are still supported just not the one with FT232BM chips, 
since it isn't possible to differentiate DMX-USB and normal-serial versions.