PP_MAJOR
MKDEV(PP_MAJOR, port->number), NULL,
device_destroy(&ppdev_class, MKDEV(PP_MAJOR, port->number));
if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR);
unregister_chrdev(PP_MAJOR, CHRDEV);
unregister_chrdev(PP_MAJOR, CHRDEV);
MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);