
Proposal 3

nest class devices, use interfaces
       /sys/class/input/
       |-- input0
       |   |-- event0
       |   `-- mouse0
       |-- input1
       |   |-- event1
       |   |-- mouse1
       |   `-- ts0
       |-- mice
       `-- interfaces
           |-- event
           |-- mouse
           `-- ts
