return 0;
return NULL;
get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id){	struct device *d, *dev;	struct device_driver *drv;	drv = get_driver(&cdrv->driver);	if (!drv)		return 0;	down_read(&drv->bus->subsys.rwsem);	dev = NULL;	list_for_each_entry(d, &drv->devices, driver_list) {		dev = get_device(d);		if (dev && !strncmp(bus_id, dev->bus_id, BUS_ID_SIZE))			break;		else if (dev) {			put_device(dev);			dev = NULL;		}	}	up_read(&drv->bus->subsys.rwsem);	put_driver(drv);	return dev ? to_ccwdev(dev) : 0;}