[alsa-devel] stereo uac device control over mixer

[Arijit De]

Hi,

I am working on a USB audio MIC device(capture device),
implemented UAC1.0 spec inside the firmware for that,
my device is a stereo uac capture? device.
I am trying to enable left and write channel separate control(volume, mute etc.) over mixer interface.

my understanding about how to enable channel specific control is
in UAC Feature Unit Descriptor
if I add bmaControls(0) and bmaControls(1) with correct bitmap for Mute & Volume support
amixer is able to identify my device as a two MIC device,

amixer output for my usb audio capture device
**********************************
Simple mixer control 'Mic',0
  Capabilities: cvolumecaps joined 780
 cvolume-joined cswitch cswitch-joined
  Capture channels: Mono
  Limits: Capture 0 - 15
  Mono: Capture 9 [60%] [27.00dB] [on]
Simple mixer control 'Mic',1
  Capabilities: cvolumecaps joined 780
 cvolume-joined cswitch cswitch-joined
  Capture channels: Mono
  Limits: Capture 0 - 15
  Mono: Capture 9 [60%] [27.00dB] [on]
**********************************

is the correct way of achieving it
OR
ideally there should be a single Mic with "Front Left - Front Right" support ?

Thanks
Arijit