Proposal 2

subclass devices and subclass drivers
       /sys/class/input
       |-- event
       |   |-- event0
       |   `-- event1
       |-- mice
       |-- mouse
       |   |-- mouse0
       |   `-- mouse1
       |-- ts
       |   `-- ts0
       `-- drivers
           |-- event
           |-- mouse
           `-- ts