extern int bus_add_device(struct device * dev);
extern void bus_attach_device(struct device * dev);
extern void bus_remove_device(struct device * dev);
-extern struct bus_type *get_bus(struct bus_type * bus);
-extern void put_bus(struct bus_type * bus);
extern int bus_add_driver(struct device_driver *);
extern void bus_remove_driver(struct device_driver *);