Comment 12 for bug 533877

>> Cool, I now have microphone 1, microphone 2, and microphone 3. Microphone 1 seems to be the digital mic. It would be nicer if it were called digital (to match alsa) but this is a huge improvement on before.

Can you provide info about your hda codec ?

THe driver check Conn since one internal mic is "Analog" and the other internal mic is "Digital"
the third one is mic jack at ext front

Node 0x0c [Pin Complex] wcaps 0x400181: Stereo
  Pincap 0x00001737: IN OUT Detect Trigger ImpSense
    Vref caps: HIZ 50 GRD 80
  Pin Default 0x90a79130: [Fixed] Mic at Int N/A
    Conn = Analog, Color = Pink
    DefAssociation = 0x3, Sequence = 0x0
    Misc = NO_PRESENCE
  Pin-ctls: 0x24: IN VREF_80
  Unsolicited: tag=00, enabled=0
  Connection: 1
     0x03

Node 0x0e [Pin Complex] wcaps 0x400181: Stereo
  Pincap 0x00001737: IN OUT Detect Trigger ImpSense
    Vref caps: HIZ 50 GRD 80
  Pin Default 0x02a79130: [Jack] Mic at Ext Front
    Conn = Analog, Color = Pink
    DefAssociation = 0x3, Sequence = 0x0
    Misc = NO_PRESENCE
  Pin-ctls: 0x24: IN VREF_80
  Unsolicited: tag=03, enabled=1
  Connection: 1
     0x04

Node 0x13 [Pin Complex] wcaps 0x400001: Stereo
  Pincap 0x00000020: IN
  Pin Default 0x90a60040: [Fixed] Mic at Int N/A
    Conn = Digital, Color = Unknown
    DefAssociation = 0x4, Sequence = 0x0
  Pin-ctls: 0x20: IN