Comment 10 for bug 1171435

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/oxygen?id=e96f38f732d24515792296b3738842934c985539

seem just using AC97 mic1 mic2 but Change the name of the control

http://cgit.freedesktop.org/pulseaudio/pulseaudio/tree/src/modules/alsa/mixer/paths/analog-input-mic.conf

you need to add Mic Source, Mic, Front Panel similar to Mic Select, Mic 1 and Mic 2 in those pulseaudio input confs

Some AC'97s have "Mic Select" and "Mic Boost (+20dB)"

[Element Mic Select]
enumeration = select

[Option Mic Select:Mic1]
name = input-microphone
priority = 20

[Option Mic Select:Mic2]
name = input-microphone
priority = 19

[Element Mic Boost (+20dB)]
switch = select
volume = merge

[Option Mic Boost (+20dB):on]
name = input-boost-on

[Option Mic Boost (+20dB):off]
name = input-boost-off