Samsung engineers previously released two revisions of this driver code, which received some feedback from developers over the past month, and they have now released the polished (third version) that incorporates the changes. This Samsung DRM driver with kernel mode-setting support uses the Intel GEM (Graphics Execution Manager) for buffer management and DMA APIs for buffer allocation. FIMD is only supported right now but HDMI support is said to come at some point in the future.
It's not clear though whether this Samsung EXYNOS driver will be accepted into the mainline Linux kernel tree since there doesn't appear to yet be any open-source user-space side with an X.Org DDX driver, Gallium3D driver, or anything similar.
If there isn't any open-source user-space side to stress these kernel bits, chances are it will be rejected since embedded GPUs are a big mess. Texas Instruments and Qualcomm both ran into similar situations in the past with only putting out open-source kernel drivers while keeping the rest of their Linux graphics stack closed-up. Who knows though what will happen with this Samsung driver as times are changing.
Find the open-source code to the Samsung EXYNOS 4210 DRM driver in this mailing list message. This would be the first ARM SoC DRM driver to go mainline.