1 What: /config/usb-gadget/gadget/functions/uac1.name
7 c_chmask - capture channel mask
8 c_srate - capture sampling rate
9 c_ssize - capture sample size (bytes)
10 p_chmask - playback channel mask
11 p_srate - playback sampling rate
12 p_ssize - playback sample size (bytes)
13 req_number - the number of pre-allocated request
14 for both capture and playback