I also want to use this I2S codec. However, the I2S/Edison hardware is not supported by the kernel. This is why you only see the Loopback device.
Have a look at this thread :
I took a quick look at the links you attached on your last post, and I noticed that it is an ALSA diver, so why don't you try installing the ALSA packages available in AlexT's Repo. Also I believe this thread might interest you: Re: Audio via I2S on edison.
Edit: Sorry I didn't see the reply above until I posted mine.
There is support for the tlv320aic3140 SOC in the kernel already (ALSA), but we also need the "platform" support to configure the I2S bus master (missing from the kernel).