Hi! With help from Paul Fertser and Jörg Reisenweber i was able to get bidirectional PCM between BT and GSM working on GTA02. I used the setup described on: http://wiki.openmoko.org/wiki/Neo1973_Audio_Subsystem#using_Bluetooth_headset_with_GSM with http://www.robsims.com/GSMBLUETOOTH.txt as ALSA state and the dac setup from http://www.robsims.com/FR-BTAudio .
This did not work correctly at first, although it now know that the state file is correct. I setup a call using FSO/zhone, which switches to gsmhandset.state. Then i loaded GSMBLUETOOTH, and setup the headset using bluez. Now the transmit path worked fine, but i couldn't hear anything in the headset. The problem here seems to he the "Capture Left Mixer" control is set to "Analogue Mix Left". When i now switch this to something different ("Analogue Mix Right") and back, the receive path starts working. Paul and Jörg suggested it might have something to do with DAPM. Also i noticed that changeing "Capture Right Mix" changes "Capture Left Mix" in paralell, but doesn't fix the audio path im my case. Jan