1/*
2 * Copyright IBM Corp. 2004
3 *
4 * Tape class device support
5 *
6 * Author: Stefan Bader <shbader@de.ibm.com>
7 * Based on simple class device code by Greg K-H
8 */
9
10#define KMSG_COMPONENT "tape"
11#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12
13#include <linux/slab.h>
14
15#include "tape_class.h"
16
17MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>");
18MODULE_DESCRIPTION(
19	"Copyright IBM Corp. 2004   All Rights Reserved.\n"
20	"tape_class.c"
21);
22MODULE_LICENSE("GPL");
23
24static struct class *tape_class;
25
26/*
27 * Register a tape device and return a pointer to the cdev structure.
28 *
29 * device
30 *	The pointer to the struct device of the physical (base) device.
31 * drivername
32 *	The pointer to the drivers name for it's character devices.
33 * dev
34 *	The intended major/minor number. The major number may be 0 to
35 *	get a dynamic major number.
36 * fops
37 *	The pointer to the drivers file operations for the tape device.
38 * devname
39 *	The pointer to the name of the character device.
40 */
41struct tape_class_device *register_tape_dev(
42	struct device *		device,
43	dev_t			dev,
44	const struct file_operations *fops,
45	char *			device_name,
46	char *			mode_name)
47{
48	struct tape_class_device *	tcd;
49	int		rc;
50	char *		s;
51
52	tcd = kzalloc(sizeof(struct tape_class_device), GFP_KERNEL);
53	if (!tcd)
54		return ERR_PTR(-ENOMEM);
55
56	strncpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);
57	for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/'))
58		*s = '!';
59	strncpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);
60	for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/'))
61		*s = '!';
62
63	tcd->char_device = cdev_alloc();
64	if (!tcd->char_device) {
65		rc = -ENOMEM;
66		goto fail_with_tcd;
67	}
68
69	tcd->char_device->owner = fops->owner;
70	tcd->char_device->ops   = fops;
71	tcd->char_device->dev   = dev;
72
73	rc = cdev_add(tcd->char_device, tcd->char_device->dev, 1);
74	if (rc)
75		goto fail_with_cdev;
76
77	tcd->class_device = device_create(tape_class, device,
78					  tcd->char_device->dev, NULL,
79					  "%s", tcd->device_name);
80	rc = PTR_RET(tcd->class_device);
81	if (rc)
82		goto fail_with_cdev;
83	rc = sysfs_create_link(
84		&device->kobj,
85		&tcd->class_device->kobj,
86		tcd->mode_name
87	);
88	if (rc)
89		goto fail_with_class_device;
90
91	return tcd;
92
93fail_with_class_device:
94	device_destroy(tape_class, tcd->char_device->dev);
95
96fail_with_cdev:
97	cdev_del(tcd->char_device);
98
99fail_with_tcd:
100	kfree(tcd);
101
102	return ERR_PTR(rc);
103}
104EXPORT_SYMBOL(register_tape_dev);
105
106void unregister_tape_dev(struct device *device, struct tape_class_device *tcd)
107{
108	if (tcd != NULL && !IS_ERR(tcd)) {
109		sysfs_remove_link(&device->kobj, tcd->mode_name);
110		device_destroy(tape_class, tcd->char_device->dev);
111		cdev_del(tcd->char_device);
112		kfree(tcd);
113	}
114}
115EXPORT_SYMBOL(unregister_tape_dev);
116
117
118static int __init tape_init(void)
119{
120	tape_class = class_create(THIS_MODULE, "tape390");
121
122	return 0;
123}
124
125static void __exit tape_exit(void)
126{
127	class_destroy(tape_class);
128	tape_class = NULL;
129}
130
131postcore_initcall(tape_init);
132module_exit(tape_exit);
133