1 What: /config/usb-gadget/gadget/functions/uac1_legacy.name
7 audio_buf_size - audio buffer size
8 fn_cap - capture pcm device file name
9 fn_cntl - control device file name
10 fn_play - playback pcm device file name
11 req_buf_size - ISO OUT endpoint request buffer size
12 req_count - ISO OUT endpoint request count