ref: 7160baf46f1f12f1b6a78a9108d07abea61bb96b
dir: /sys/src/cmd/nusb/usbd/fns.h/
void attachdev(Dev*); void detachdev(Dev*); void work(void); Hub* newhub(char *, Dev*); int hname(char *); void assignhname(Dev *dev); void checkidle(void); int portfeature(Hub*, int, int, int);