MAX_DOGS
id = ida_alloc_max(&watchdog_ida, MAX_DOGS - 1, GFP_KERNEL);
id = ida_alloc_range(&watchdog_ida, 1, MAX_DOGS - 1,
err = alloc_chrdev_region(&watchdog_devt, 0, MAX_DOGS, "watchdog");
unregister_chrdev_region(watchdog_devt, MAX_DOGS);