ALSA: usb-audio: Add quirk for MOTU MicroBook II
Add an entry to the quirks-table to for usb-audio to recognize the Microbook II (although it only exposes vendor interfaces). A simple boot quirk is also implemented to set up the sample rate and make sure that no audio urbs are sent before the device is ready. This patch only provides audio playback and capture at 96kHz sample rate. Notice the following shortcomings: - The sample rate is currently hardcoded to 96k although the device also supports 48k and 44.1k. - The various mixer controls of the MicroBook are not made available. - The keep-iface control should be on by default because the device shuts down whenever the altsetting is reset which is usually unwanted. (I don't know the best way to do this) - The communication format used by the MicroBook for sample rate setting and also other setup has been reverse engineered by looking at the usbmon output while running the windows driver through virtualbox. In this patch the first byte of every message is set to \0 while in the observed communications the first byte acts as a "message-counter" increasing its value with every message sent. Leaving it at \0 does not seem to affect the device. Signed-off-by:Manuel Reinhardt <manuel.rhdt@gmail.com> Signed-off-by:
Takashi Iwai <tiwai@suse.de>
parent
70395a96
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