I found ad18x and bf53x_sport -files on bfin-docs, which are for bf537-ez kit audio (AD1871 & AD1854) combined soc driver by Alex Pimenov. Some includes needed to be added and alsa init was changed from the version used in code. After compilation and making new kernel, no crahes, but coudn't get sound out. Then remembered that the switch was in some position found on these forums to get sound out using ad1836. Moved the switches to original position, all on, and wave-file is played just fine, even if I didn't touch alsa-configs. But recording doesn't work. strace arecord ... gives in open /dev/snd/pcmC0D0c invalid argument. On these forums and several other places there are so much different settings for configs, that I really don't know where to start. Most were related in this specific record-problem some config err. I copied the AD1980.conf and changed few lines, format, srate and channels are same, but no go. There are in /usr/share/alsa settings for all kinds of audio-configurations, but the snd-ad18x doesn't have a mixer, so many are not valid.
If somebody has any simple solution to this problem, I'd really be thankful and would like to try. But even getting audio out is very good. If code needs audio-in, nfsroot-system makes it possible to read from disk.