Hi,
I'm working on a RPi based audio analyzer, which requires simultaneous playback and record at 24bit 192ksps.
I used BCM2708-I2S module, and I wrote my own audio machine definition and codec definition.
My own driver works fine if I only declare the playback interface. When I tried to declare recording interface or both, the module won't be started.
Here is the problem: "bcm2708-i2s 3f203000.i2s: missing DMA channel for stream: 1".
I modified the driver from /sound/soc/bcm/rpi-dac.c and rpi-proto.c, as well as /sound/soc/codecs/pam1794a.c and wm8804.c.
Also, I referred to Cirrus Logic's audio HAT's driver, and did not spot too many different.
I derived my device tree descriptor file from rpi-dac's as well as Cirrus Logic's.
So far, no progress. Any thoughts?
Thanks,
Bo