ref: 4cd46e8601a04d2dc4fa91f95f5be4be14943c96
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);