Hello,
I wrote a low-level parallel port driver for the built-in port on SGI
O2 (a.k.a. IP32).
The parallel port is driven by a standard ECP chipset, with
memory-mapped I/O registers. That's why it was not possible to use
the parport_pc module which assumes port-mapped I/O registers.
What works:
* Basic modes are supported: PCSPP, PS2.
* Compatibility mode with FIFO support is present.
* FIFO can be driven with or without interrupts.
What does not work:
* DMA support is not implemented (lack of documentation). If you
have any information, please tell me.
* EPP and ECP modes are not implemented (lack of interest). I
currently do not own any peripheral supporting this extended
modes. It should not be too difficult to do.
All tests were done with an HP LaserJet 5MP connected to a R5000 SGI
O2.
The module is named parport_ip32. The patch is not included in this
mail because it is not very small (2383 lines, 73 Kb). It is however
avalaible from:
http://arnaud.giersch.free.fr/parport_ip32/parport_ip32-latest.patch.gz
The patch is against the latest Linux/MIPS kernel (2.6.14-rc2 as of
today). If you prefer that I post it on a mailing list, please just
tell me where, and how (inlined, or gzip'ed attached file).
Further informations are available on:
http://arnaud.giersch.free.fr/parport_ip32.html
Regards,
Arnaud Giersch
