Does it just need a new driver then?
Interesting thought... But I think that the incompatible part of the "protocol" is actually more like the link layer, which is handled by hardware. (ie, a PS/2 compatible keyboard is designed to talk with an i8042, where an Amiga compatible keyboard is designed to talk to whatever the heck handles it on Amiga.)
Without the link layer, you can't pull the raw keycodes. Otherwise, seemingly, you'd just need to write a PS/2 keymap, which I know isn't the case.
