[Asterisk-Dev] Zaptel development question

[creslin at digium.com]

On Wed, Oct 13, 2004 at 11:02:33AM -0700, Kevin P. Fleming wrote:
> Steven Sokol wrote:
> 
> >Does anybody else see what I am missing -- an ioctl call to the control 
> >interface (/dev/zap/ctl) that will return card-specific information?  
> >The generic ZT_GET_PARAMS doesn't seem to pass that bit of data back, 
> >and I don't see any other driver calls that would return structures with 
> >module (driver) specific data.
> >
> >Anybody else have thoughts?
> 
> Well, yeah, I have thoughts, but they are along a different line. I 
> would suggest enhancing the Zaptel modules to support sysfs (/sys), and 
> report this information there. That's exactly what it's intended for, 
> and it's much easier to use than ioctls, plus it doesn't have to mangled 
> for different platforms (unlike ioctls, which work differently on 
> 32-bit, 64-bit and mixed 32/64-bit environments).
> 
> Just exactly how to present the information there (as a device, or a 
> class, or whatever) would have to be figured out with the help of the 
> kernel devs that work on this stuff, but that wouldn't be too difficult 
> to manage. I haven't tried, though, since I haven't got time to 
> implement it in Zaptel... if someone else does, I'll be happy to help 
> figure out what the interface should be.

It's relatively simple.  I did the zaptel udev support code (including /sysfs
support) and it's pretty straightforward.  You shouldn't have too much
difficulty presenting the information in /sysfs and exposing it to the
outside world.  I didn't do any file-information interfaces though for
zaptel but the basic framework should be there, just look at the existing
code that sets up the sysfs entries for zaptel to start.

Matthew Fredrickson