Due to my limited time I have not developed this driver anymore. You should try http://www.uni-bonn.de/~uzsa69/za2.html to get a working driver, although this driver is not integrated in ALSA.
Right now my driver for ZA2 supports 16bit, stereo, 20kHz-60kHz output. Input is not tested so far. If you want to test the driver, you'll find it at ftp://ftp.tnt.uni-hannover.de/pub/misc/alsa-za2