Hi,
I am working on DM3730 EVM board, want to enable Microphone.
TPS64950 pins MIC.MAIN.P (E2) and MIC.MAIN.M (F2) are connected to Microphone.
As given below : 
I followed the link :
http://e2e.ti.com/support/microcontrollers/stellaris_arm_cortex-m3_microcontroller/f/471/p/addpost.aspx
and using the following command :
amixer cset name='HeadsetR Mixer AudioR2' off
amixer set HandsfreeL on
amixer set HandsfreeR on
amixer set 'HandsfreeL Mux' AudioL2
amixer set 'HandsfreeR Mux' AudioR2
to enable the speaker,it is working fine.
For enable Microphone using the following commands :
amixer set 'Analog Left AUXL' nocap
amixer set 'Analog Right AUXR' nocap
amixer set 'Analog Left Main Mic' nocap
amixer set 'Analog Left Headset Mic' cap
and capturing data to arecord command arecord -vv file.wav and using aplay -vv file.wav to playback,it is playing back only noise data.
Please suggest whether we need to change any settings or handle the code in kernel.
thanks
Vidya.