custom parallel interface driver

["Andrea Galbusera" <gizero@gmail.com>]

In the context of a PowerPC Linux project I am required to support a
custom parallel interface. The hardware module implementing such
interface lives on a FPGA board connected to the PowerPC by the PCI
bus.

I'm reading developer's docs about the parport subsystem: I'm asking
myself how to use (if possible) all that already available code. Do I
have to develop a new low-level driver using pci and parport
interfaces? Or may I expect to be able to use parport_pc?
Unfortunately I still don't have the hardware available and I'm
evaluating the complexity of this task.

Here are some specifications of the hardware module to support (not
developed by me):
- single unidirectional Centronics-like with control signals interface
- 1K x 8bit FIFO for data

Minimal driver requirements are:
- capability to read data from the FIFO (possiblbly through ususal
device file interfaces and using interrupts)
- capability to read/write control registers of the interface

These may sound as very preliminar questions. In fact, they are! My
kernel development experience is just at the beginning, but I have a
basic knowledge of kernel module writing and I read Rubini's book on
the subject.

Hope somebody can suggest me how to approach the problem, to avoid
re-inventing the wheel...

TIA