Device driver advice needed.

[Frank Mayhar]

I have become the owner of a Specialix I/O8+ PCI multiport serial card.
I originally thought that FreeBSD had a driver for that card, but it
turns out that the si(4) driver only supports the older SI/XIO and SX
cards.  Fortunately, Linux has an I/O8+ driver and I'm in contact with
the author, Roger Wolff.  While there isn't any documentation available
for the I/O8+ itself, there is documentation for the CD1865 chipset it
uses.  Between that, the Linux source and Roger's apparent willingness
to answer questions, I should be able to come up with a working driver
without too terribly much effort.

I'm targeting 4-stable, since that's the platform for which I need support.
I had originally thought I would add the I/O8+ support to the existing
si(4) driver, but I just learned that the I/O8+ is sufficiently different
from the SX series that Roger wrote two different drivers for Linux.  Now
I'm strongly leaning toward writing a new driver, call it "sx(4)."  For
4-stable, I'll need a new major to be allocated, although I understand that
in 5.x devfs eliminates that requirement.  Still, for the moment, I'm stuck
with 4-stable.  I also need some advice as to how to name the devices in
/dev.  The si(4) driver uses /dev/ttyA* and /dev/cuaA*; perusing MAKEDEV
it appears that I might use /dev/ttyG* and /dev/cuaG*.  Is there a
convention I should use?

Finally, I've also come across an SDK for the SX series, with documentation,
that includes support for the newer SX+ card.  I don't have one of those
and therefore can't test the code, but it appears relatively easy to add
the support for the newer card to the existing driver.  If someone wants
to pick it up I would be happy to hand it to them.  Peter Wemm, who ported
the si(4) driver from BSD/OS would be the logical choice, if he's interested.
If I have time and am ambitious, I might add the support myself, but that's
a pretty big "if."

Suggestions and advice solicited.  Theses cheerfully roundfiled.
-- 
Frank Mayhar frank at exit.com	http://www.exit.com/
Exit Consulting                 http://www.gpsclock.com/
                                http://www.exit.com/blog/frank/