I'd have exported a function creating FU mixer element instead of the control element link, but your patches are simple enough, so I applied as is.
I can have a look at this later and send a fixup.
Thanks to everyone involved for efforts in developing and merging this support.
So when Takashi says he's applied it what git branch/repo is that if it's published?
So I thought it might be worthwhile sumarising the current status of the Fast track ultra support in alsa from a user perspective:
Done working 100%: Recording at all supported sample rates (44.1, 48, 88.2 and 96)kHz Mixer support for channel routing within the device (thanks to Daniel and Felix) Midi in and out.
Still needing work for full functionality (device is usable as is these things would make support as good as vendor (other os) drivers):
Playback works but has an odd artifact that's quite noticable when playing back pure sine functions (seems to drop a sample once every some power of 2 it's not the end of the world and is not noticable in normal use. This was discussed on this list in september however it remains unresolved. I should test my other usb soundcards and verify it's only the FTU that's affected tho.
The remaining mixer controls and switches (dsp/reverb sends and setting and internal/external clock controls) now we have a framework for the mixer support adding the remaining controls should be straightforward the big challenge imho was how to integrate into the quirk code.
Grant.