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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright IBM Corp. 20044 *5 * Tape class device support6 *7 * Author: Stefan Bader <shbader@de.ibm.com>8 * Based on simple class device code by Greg K-H9 */10 11#define KMSG_COMPONENT "tape"12#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt13 14#include <linux/slab.h>15 16#include "tape_class.h"17 18MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>");19MODULE_DESCRIPTION(20 "Copyright IBM Corp. 2004 All Rights Reserved.\n"21 "tape_class.c"22);23MODULE_LICENSE("GPL");24 25static const struct class tape_class = {26 .name = "tape390",27};28 29/*30 * Register a tape device and return a pointer to the cdev structure.31 *32 * device33 * The pointer to the struct device of the physical (base) device.34 * drivername35 * The pointer to the drivers name for it's character devices.36 * dev37 * The intended major/minor number. The major number may be 0 to38 * get a dynamic major number.39 * fops40 * The pointer to the drivers file operations for the tape device.41 * devname42 * The pointer to the name of the character device.43 */44struct tape_class_device *register_tape_dev(45 struct device * device,46 dev_t dev,47 const struct file_operations *fops,48 char * device_name,49 char * mode_name)50{51 struct tape_class_device * tcd;52 int rc;53 char * s;54 55 tcd = kzalloc(sizeof(struct tape_class_device), GFP_KERNEL);56 if (!tcd)57 return ERR_PTR(-ENOMEM);58 59 strscpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);60 for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/'))61 *s = '!';62 strscpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);63 for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/'))64 *s = '!';65 66 tcd->char_device = cdev_alloc();67 if (!tcd->char_device) {68 rc = -ENOMEM;69 goto fail_with_tcd;70 }71 72 tcd->char_device->owner = fops->owner;73 tcd->char_device->ops = fops;74 75 rc = cdev_add(tcd->char_device, dev, 1);76 if (rc)77 goto fail_with_cdev;78 79 tcd->class_device = device_create(&tape_class, device,80 tcd->char_device->dev, NULL,81 "%s", tcd->device_name);82 rc = PTR_ERR_OR_ZERO(tcd->class_device);83 if (rc)84 goto fail_with_cdev;85 rc = sysfs_create_link(86 &device->kobj,87 &tcd->class_device->kobj,88 tcd->mode_name89 );90 if (rc)91 goto fail_with_class_device;92 93 return tcd;94 95fail_with_class_device:96 device_destroy(&tape_class, tcd->char_device->dev);97 98fail_with_cdev:99 cdev_del(tcd->char_device);100 101fail_with_tcd:102 kfree(tcd);103 104 return ERR_PTR(rc);105}106EXPORT_SYMBOL(register_tape_dev);107 108void unregister_tape_dev(struct device *device, struct tape_class_device *tcd)109{110 if (tcd != NULL && !IS_ERR(tcd)) {111 sysfs_remove_link(&device->kobj, tcd->mode_name);112 device_destroy(&tape_class, tcd->char_device->dev);113 cdev_del(tcd->char_device);114 kfree(tcd);115 }116}117EXPORT_SYMBOL(unregister_tape_dev);118 119 120static int __init tape_init(void)121{122 return class_register(&tape_class);123}124 125static void __exit tape_exit(void)126{127 class_unregister(&tape_class);128}129 130postcore_initcall(tape_init);131module_exit(tape_exit);132