FB_MAJOR
ret = register_chrdev(FB_MAJOR, "fb", &fb_fops);
pr_err("Unable to get major %d for fb devs\n", FB_MAJOR);
unregister_chrdev(FB_MAJOR, "fb");
dev_t devt = MKDEV(FB_MAJOR, node);
dev_t devt = MKDEV(FB_MAJOR, fb_info->node);