Before getting too excited, this isn't some official Mali open-source GPU driver or something super exciting, but is the PL111 DRM driver. This is an open-source display driver to provide mode-setting support for the pl111 CLCD display controller found on some reference ARM platforms, including their Versatile Express.
It's a standard and is a DRM driver rather than just an fbdev driver as some other ARM SoCs have done. However, this CLCD mode-setting driver for now is quite limited and is hard-coded to mode-set at 640 x 480.
This DRM driver can be used in conjunction with the xf86-video-armsoc X.Org DDX driver.
This ARM DRM driver for now can be found on the dri-devel mailing list.