I installed fglrx-updates on a fresh install of Mint 17.2 via this guide for Ubuntu 14.04. When I type in
$ fglrxinfo
display: :0 screen: 0
OpenGL vendor string: X.Org
OpenGL renderer string: Gallium 0.4 on AMD CAYMAN
OpenGL version string: 3.0 Mesa 10.1.3
I've tried purging it and reinstalling it as fglrx instead of fglrx-updates to no avail. If I type
$ amdcccle
It tells me that "There was a problem initializing Catalyst Control Center Linux edition. It could be caused by the following.
No AMD graphics driver is installed, or the AMD driver is not functioning properly. Please install the AMD driver appropriate for you AMD hardware, or configure using aticonfig."
I'm running an HD 6970.