HelenOS sources

sdir_input        315 uspace/drv/audio/hdaudio/pcm_iface.c 	hda->pcm_stream = hda_stream_create(hda, sdir_input, hda->pcm_buffers,
sdir_input        233 uspace/drv/audio/hdaudio/stream.c 	case sdir_input:
HelenOS homepage, sources at GitHub