I've added support for HDMI audio support on my Evergreen 1002:9806. It works great for me, however to make it work on all Evergreens I need dumps from other machines.
Who can help?
1) Evergreen GPU
2) Audio capable TV/monitor
3) Knowledge to checkout, modify and compile radeontool
4) Courage to install fglrx
How to help?
Let's start with the installation of radeontool (it contains avivotool we will use).
After that you've to install fglrx, connect audio capable TV/monitor and play some music over HDMI. While playing music (make sure it works, that you hear it), execute the following:
git checkout git://people.freedesktop.org/~airlied/radeontool
git am 0001-avivotool-dump-0000-e000-as-all-on-Evergreen.patch
./autogen.sh && make && sudo make install
avivotool regs all > fglrx.txt
That's it. Please provide me via e-mail following info:
1) lspci -nn | grep VGA
2) dmesg | grep drm