While I am sure that Sony has code that they keep proprietary, its worth noting that thy have contributed quite a bit back to FreeBSD (AVX support comes to mind) as well as LLVM.
FreeBSD has full support for GPIO and i2c on both the RPi 1 and 2. Simple wrappers around FreeBSD's GPIO ioctl can be found at https://github.com/gonzoua/freebsd-gpio
If you are interested in creating a FreeBSD image for the Raspberry Pi, take a look at crochet [1] which is a script that pretty much automates the steps outlined in the wiki. In addition, it can also be used to create images for Beaglebone and other ARM (and MIPS I believe) platforms
http://www.freshports.org/archivers/lzfse/