[Discuss-gnuradio] Looking for help on 2.6 driver udev/sysfs

[Eric Blossom]

Hi Folks,

The mc4020 driver is now working under 2.6 with one outstanding
problem: creating device files.

Apparently the new and improved method of creating devices files uses
udev plus sysfs to automatically create device files for devices.

Meenal pointed out that under FC3, you can work around this feature by
creating device nodes in /etc/udev/devices.  They are created in
/dev at boot time.  The problem is that this is FC3 specific, and
doesn't work on other 2.6 systems.

After doing some reading, it looks like the right answer is 
to get each mc4020 to show up in /sys/class/ using
"class_simple_create" and friends.  

If any of you have been through this before, I'd appreciate your
help.  I suspect this is no big deal if you know how to do it.
The driver itself is working fine.  It's been running for over 2 days
with no problems.

I'd also entertain any other solution that worked robustly.

We have been using major number 127, which is reserved for
experimental use (should be OK).  For each mc4020 in the system, two
device files should be created.  In a system with two 4020's they
should look something like this:

crw-rw-rw-  1 root root 127,  0 Feb  4 18:58 mc4020_0
crw-rw-rw-  1 root root 127,  1 Feb  4 18:58 mc4020_1
crw-rw-rw-  1 root root 127, 16 Feb  4 18:58 mc4020aux0
crw-rw-rw-  1 root root 127, 17 Feb  4 18:58 mc4020aux1

The driver code is in CVS: http://comsec.com/wiki?CvsAccess

Eric