First heads up in 2013: I got nerd-sniped shortly after x-mas and reverse-engineered the Digi 003 Firewire protocol with Damien Zammit. The details are a long story, but linux-support for it is underway:
The rebased driver code is at http://gareus.org/gitweb/?p=alsa-driver.git and the broken-out digi003 driver is available from https://github.com/x42/003amdtp.