Spinlock for accessing graphical hardware (G400)

Hi

I would like to know if there is any way, how could I create my own driver for
the graphics card (G400) - I mean there are XFree, DRM, mga conscole and I want
to se my own driver - but I really need something like common lock for accessing
hardware registers.

Is there any way how one could one achieve such thing on SMP machine ? Does anyone plan to add such thing ?
(I do not want to add my driver to Drm nor to console device)

thanks

kabi