> Question is how to connect the userspace? I think that corresponding > file in /sys would do the job, but I am not sure whether it is the > proper way of doing that. (?)
A historian might be able to help you. Going back to the days of 10MBps Ethernet, cards used to have a few different ports, AUI, BNC and TP. The kernel probably supports configuring which to use, probably via ethtool. Your use case is not that different, so you can probably reuse it. Andrew