There are docs for some things, including beyond basic modesetting: http://download.nvidia.com/open-gpu-doc/ http://download.nvidia.com/open-gpu-doc/ They at l

There are docs for some things, including beyond basic modesetting: http://download.nvidia.com/open-gpu-doc/ http://download.nvidia.com/open-gpu-doc/ They at least used to be responsive to questions a couple of years back when they started publishing the docs, but I'm not up-to-date on the present situation.