Generic Digital Microphone CODEC

modulename: snd-soc-dmic.ko

configname: CONFIG_SND_SOC_DMIC

Linux Kernel Configuration
└─>Device Drivers
└─>Sound card support
└─>Advanced Linux Sound Architecture
└─>ALSA for SoC audio support
└─>CODEC drivers
└─>GPIO Support
└─>Generic Digital Microphone CODEC
In linux kernel since version 2.6.38 (release Date: 2011-03-14)  
Enable support for the Generic Digital Microphone CODEC.
Select this if your sound card has DMICs.

source code:
sound/soc//codecs/