1/*
2 * (C) Copyright IBM Corp. 2004
3 * tape_class.c
4 *
5 * Tape class device support
6 *
7 * Author: Stefan Bader <shbader@de.ibm.com>
8 * Based on simple class device code by Greg K-H
9 */
10#include "tape_class.h"
11
12MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>");
13MODULE_DESCRIPTION(
14	"(C) Copyright IBM Corp. 2004   All Rights Reserved.\n"
15	"tape_class.c"
16);
17MODULE_LICENSE("GPL");
18
19static struct class *tape_class;
20
21/*
22 * Register a tape device and return a pointer to the cdev structure.
23 *
24 * device
25 *	The pointer to the struct device of the physical (base) device.
26 * drivername
27 *	The pointer to the drivers name for it's character devices.
28 * dev
29 *	The intended major/minor number. The major number may be 0 to
30 *	get a dynamic major number.
31 * fops
32 *	The pointer to the drivers file operations for the tape device.
33 * devname
34 *	The pointer to the name of the character device.
35 */
36struct tape_class_device *register_tape_dev(
37	struct device *		device,
38	dev_t			dev,
39	const struct file_operations *fops,
40	char *			device_name,
41	char *			mode_name)
42{
43	struct tape_class_device *	tcd;
44	int		rc;
45	char *		s;
46
47	tcd = kzalloc(sizeof(struct tape_class_device), GFP_KERNEL);
48	if (!tcd)
49		return ERR_PTR(-ENOMEM);
50
51	strncpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);
52	for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/'))
53		*s = '!';
54	strncpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);
55	for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/'))
56		*s = '!';
57
58	tcd->char_device = cdev_alloc();
59	if (!tcd->char_device) {
60		rc = -ENOMEM;
61		goto fail_with_tcd;
62	}
63
64	tcd->char_device->owner = fops->owner;
65	tcd->char_device->ops   = fops;
66	tcd->char_device->dev   = dev;
67
68	rc = cdev_add(tcd->char_device, tcd->char_device->dev, 1);
69	if (rc)
70		goto fail_with_cdev;
71
72	tcd->class_device = class_device_create(
73				tape_class,
74				NULL,
75				tcd->char_device->dev,
76				device,
77				"%s", tcd->device_name
78			);
79	rc = IS_ERR(tcd->class_device) ? PTR_ERR(tcd->class_device) : 0;
80	if (rc)
81		goto fail_with_cdev;
82	rc = sysfs_create_link(
83		&device->kobj,
84		&tcd->class_device->kobj,
85		tcd->mode_name
86	);
87	if (rc)
88		goto fail_with_class_device;
89
90	return tcd;
91
92fail_with_class_device:
93	class_device_destroy(tape_class, tcd->char_device->dev);
94
95fail_with_cdev:
96	cdev_del(tcd->char_device);
97
98fail_with_tcd:
99	kfree(tcd);
100
101	return ERR_PTR(rc);
102}
103EXPORT_SYMBOL(register_tape_dev);
104
105void unregister_tape_dev(struct tape_class_device *tcd)
106{
107	if (tcd != NULL && !IS_ERR(tcd)) {
108		sysfs_remove_link(
109			&tcd->class_device->dev->kobj,
110			tcd->mode_name
111		);
112		class_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	tape_class = class_create(THIS_MODULE, "tape390");
123
124	return 0;
125}
126
127static void __exit tape_exit(void)
128{
129	class_destroy(tape_class);
130	tape_class = NULL;
131}
132
133postcore_initcall(tape_init);
134module_exit(tape_exit);
135