Writing a linux hardware driver

I have build a POV display 8 X 10 pixels that runs from the parallel
port.
Right now I have a some crude code in 'C' that displays static images.
Would like to interface it with Amarok or Xine engine to display freq.
graph or some effects.

I would like to write a driver so I don't have to be Root to access
the parallel port.
And make it sort of open so that if I make a larger display can reuse
the code or some other parallel project.

Function's I am thinking of:

1. Init the device
2. open device "User"
2. Create a display buffer's, option of multiple buffers for
animation.
3. Write to buffer
4. Read buffer
5. Clear buffer
6. Control, Refresh speed for display, set active buffer
7. Close device "User"
8. Remove device

My though is that once the driver is initialized it will loop through
the selected buffer at a set times per second. What I am not sure
about is how you make the driver do this as a back ground task of
refreshing the display. Looking for some suggestions, maybe if there
is some code out there similar to what I want to do.

Eric

I've used paraport in the past for custom device interaction under Linux: http://people.redhat.com/twaugh/parport/
You could modify the driver or even use it as-is from a user-mode app.

Linux driver resource: http://www.linuxdriver.co.il/ldd3/

gg