I have implemented GPIOLIB support for RDC chips, and attached the kernel patch to the Bifferboard wiki here:

http://sites.google.com/site/bifferboard/Home/gpio

The patch should be OK to apply to 2.6.30.5, and AFAIK should work with any RDC-based router.  In case you don't know what GPIOLIB is, it allows you to change GPIO values via a sysfs interface - a basic guide has been added to the wiki.

feedback welcome.

regards,
Biff.