The Radeon DRM driver already has a few features in its development branch that is being prepared for merging into the future Linux 3.7 kernel
Alex Deucher of AMD has posted a branch this week entitled drm-next-3.7-wip
that is queuing up changes for merging into the next Linux kernel series.
Notable work in this "work in progress" branch includes ROM fetch fixes for UEFI and Thunderbolt docks, a major ACPI re-work, and back-light control support for newer Radeon chipsets.
The Radeon ACPI improvements come one month after AMD released a new header file
for working to improve the power management of this open-source Linux graphics driver. This includes initial support for ATCS ACPI methods, reorganizing the ATPX support, documenting Radeon ACPI code, and other code re-factoring.
The back-light control support for hardware where the GPU has a built-in back-light controller and Atom tables can be used for adjusting the brightness level.
This new Radeon kernel driver code branch was mentioned on the dri-devel list
and can be pulled from Alex's FreeDesktop.org repository