SoC Audio for the Tegra System-on-Chip

modulename: snd-soc-tegra-pcm.ko

and/or

snd-soc-tegra-utils.ko

configname: CONFIG_SND_SOC_TEGRA

Linux Kernel Configuration
└─>Device Drivers
└─>Sound card support
└─>Advanced Linux Sound Architecture
└─>ALSA for SoC audio support
└─>SoC Audio for the Tegra System-on-Chip
In linux kernel since version 3 (release Date: 2011-07-21)  
Say Y or M here if you want support for SoC audio on Tegra.

source code:
sound/soc//tegra/