Xone43C: USB communication

[Roman Muller]

Hello Geraldo, hello all,

sorry for spamming the list with such minuscule details.
Thank you for your message! I did not hear from other people yet,
so it's probably safe to assume that no one else is already working on it.
Adding a section to the quirks-table does not help, the vendor-specific
interfaces still don't work. Obviously they need extra initialization.

Next step: sniffing again while running Windows in the vm.
The interesting stuff is going on here:
https://drive.google.com/file/d/1IlkR4ey9Gwsdrrf6jfOwNUVDtGcl_93-
(Full log: https://drive.google.com/file/d/1VmSGVk8V1saw7qdPfbOH2d4HmZTrlzxj)

From this I see several URB control messages going back and forth, for example
the host sending 80bbf0, and the device responding accordingly. A bit later,
and after sending 44ac00 six times (hola!?!?) I get isodesc[0-7] cross-device
link for input; and once more for output, and the device reports success. These
appear to be my eight channels. So far, so good for a first basic overview of
the structure, but the tricky part is figuring out what message is doing what.
Only the manufacturer knows it, I need experiment and guessing
with a lot of time and luck.
Is there a common agreement where in the source code such control
messages should be put? Probably an extra file?

Best,
Roman