Install the midisport-firmware package (firmware is in the package and the package should be available via the debian package repository)
sudo apt-get install midisport-firmware
sudo touch /etc/udev/rules.d/99-midisport-firmware.rules
sudo vi /etc/udev/rules.d/99-midisport-firmware.rules
In the editor, paste the following rules:
# midisport-firmware.rules - udev rules for loading firmware into MidiSport devices
# MidiSport 1x1
ACTION=="add", SUBSYSTEM=="usb*", ATTRS{idVendor}=="0763", ATTRS{idProduct}=="1010", RUN+="/sbin/fxload -s /usr/share/usb/maudio/MidiSportLoader.ihx -I /usr/share/usb/maudio/MidiSport1x1.ihx -D %N"
# MidiSport 2x2
ACTION=="add", SUBSYSTEM=="usb*", ATTRS{idVendor}=="0763", ATTRS{idProduct}=="1001", RUN+="/sbin/fxload -s /usr/share/usb/maudio/MidiSportLoader.ihx -I /usr/share/usb/maudio/MidiSport2x2.ihx -D %N"
# KeyStation
ACTION=="add", SUBSYSTEM=="usb*", ATTRS{idVendor}=="0763", ATTRS{idProduct}=="1014", RUN+="/sbin/fxload -s /usr/share/usb/maudio/MidiSportLoader.ihx -I /usr/share/usb/maudio/MidiSportKS.ihx -D %N"
# MidiSport 4x4
ACTION=="add", SUBSYSTEM=="usb*", ATTRS{idVendor}=="0763", ATTRS{idProduct}=="1020", RUN+="/sbin/fxload -s /usr/share/usb/maudio/MidiSportLoader.ihx -I /usr/share/usb/maudio/MidiSport4x4.ihx -D %N"
# MidiSport 8x8
ACTION=="add", SUBSYSTEM=="usb*", ATTRS{idVendor}=="0763", ATTRS{idProduct}=="1031", ATTRS{bcdDevice}=="0110", RUN+="/sbin/fxload -s /usr/share/usb/maudio/MidiSportLoader.ihx -I /usr/share/usb/maudio/MidiSport8x8-2.10.ihx -D %N"
ACTION=="add", SUBSYSTEM=="usb*", ATTRS{idVendor}=="0763", ATTRS{idProduct}=="1031", ATTRS{bcdDevice}=="0121", RUN+="/sbin/fxload -s /usr/share/usb/maudio/MidiSportLoader.ihx -I /usr/share/usb/maudio/MidiSport8x8-2.21.ihx -D %N"
# vim: ft=conf
Upon saving the file, the rules will refresh and you can then connect your midi sport device. The active light of the device should be on/flickering.