> Meaning no offense, but I can't think of a single good reason to write a
> device driver for one of these cards. (Unless you're trying to do
> pattern generation, and an 8255 is a terrible choice for that.) Worse
> than that though, there's _no_ standard for these cards' implementation,
> so a driver isn't going to be even vageuly portable.
>
> Use i386_set_ioperm() and just bit-bash it in userspace.
The bit-bashing in userspace will make this even less portable. The idea is
liked by those around here of being able to do a 'set register 0', or
'clear register 0' with an ioctl() and leaving the implementation to
"something else", which can key on what type of board it is and DtRT.
Also, how would you trap interrupts from such a card (for when using it as
a digital input) from userland?
Since it is already written, and in operation. Unless we are low on major
numbers, or this could be better merged with another interface, it seems to
be a waste to not give it a major number. Bringing it into the base CVS
tree is another question entirely, but it would appear at least one has
already expressed an interest. BTW: the URL for the card that was
given to me for this project is at:
http://www.computerboards.com/cbicatalog/cbiproduct.asp?dept%5Fid=224&pf%5Fid=668&mscssid=50A6V97GWTSH2J6N000JU4JKRUFAAEGB
Product descriptions and a technical manual are linked from that page.
--
David Cross | email: [EMAIL PROTECTED]
Acting Lab Director | NYSLP: FREEBSD
Systems Administrator/Research Programmer | Web: http://www.cs.rpi.edu/~crossd
Rensselaer Polytechnic Institute, | Ph: 518.276.2860
Department of Computer Science | Fax: 518.276.4033
I speak only for myself. | WinNT:Linux::Linux:FreeBSD
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