Ambient Light Sensor on M3800 DE

A small handful of people have been maintaining a forum thread on getting Gentoo running up and properly on the M3800 developer edition model:  

https://forums.gentoo.org/viewtopic-p-7742824.html

Does anyone happen to know what ambient light sensor is used on this laptop?  As far as I can tell, that's the last piece of hardware that we don't have working yet.  I've tried compiling several of the usual candidates that I've seen like the Taos modules from IIO and staging IIO, but those don't seem to correspond to whatever ALS hardware is in the laptop.