summaryrefslogtreecommitdiffstats
path: root/drivers/s390/char/tape_class.c
blob: 277a0f903d11bfdb50e2c545286358dac3c8a86a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright IBM Corp. 2004
 *
 * Tape class device support
 *
 * Author: Stefan Bader <shbader@de.ibm.com>
 * Based on simple class device code by Greg K-H
 */

#define KMSG_COMPONENT "tape"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/slab.h>

#include "tape_class.h"

MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>");
MODULE_DESCRIPTION(
	"Copyright IBM Corp. 2004   All Rights Reserved.\n"
	"tape_class.c"
);
MODULE_LICENSE("GPL");

static struct class *tape_class;

/*
 * Register a tape device and return a pointer to the cdev structure.
 *
 * device
 *	The pointer to the struct device of the physical (base) device.
 * drivername
 *	The pointer to the drivers name for it's character devices.
 * dev
 *	The intended major/minor number. The major number may be 0 to
 *	get a dynamic major number.
 * fops
 *	The pointer to the drivers file operations for the tape device.
 * devname
 *	The pointer to the name of the character device.
 */
struct tape_class_device *register_tape_dev(
	struct device *		device,
	dev_t			dev,
	const struct file_operations *fops,
	char *			device_name,
	char *			mode_name)
{
	struct tape_class_device *	tcd;
	int		rc;
	char *		s;

	tcd = kzalloc(sizeof(struct tape_class_device), GFP_KERNEL);
	if (!tcd)
		return ERR_PTR(-ENOMEM);

	strscpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);
	for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/'))
		*s = '!';
	strscpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);
	for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/'))
		*s = '!';

	tcd->char_device = cdev_alloc();
	if (!tcd->char_device) {
		rc = -ENOMEM;
		goto fail_with_tcd;
	}

	tcd->char_device->owner = fops->owner;
	tcd->char_device->ops   = fops;

	rc = cdev_add(tcd->char_device, dev, 1);
	if (rc)
		goto fail_with_cdev;

	tcd->class_device = device_create(tape_class, device,
					  tcd->char_device->dev, NULL,
					  "%s", tcd->device_name);
	rc = PTR_ERR_OR_ZERO(tcd->class_device);
	if (rc)
		goto fail_with_cdev;
	rc = sysfs_create_link(
		&device->kobj,
		&tcd->class_device->kobj,
		tcd->mode_name
	);
	if (rc)
		goto fail_with_class_device;

	return tcd;

fail_with_class_device:
	device_destroy(tape_class, tcd->char_device->dev);

fail_with_cdev:
	cdev_del(tcd->char_device);

fail_with_tcd:
	kfree(tcd);

	return ERR_PTR(rc);
}
EXPORT_SYMBOL(register_tape_dev);

void unregister_tape_dev(struct device *device, struct tape_class_device *tcd)
{
	if (tcd != NULL && !IS_ERR(tcd)) {
		sysfs_remove_link(&device->kobj, tcd->mode_name);
		device_destroy(tape_class, tcd->char_device->dev);
		cdev_del(tcd->char_device);
		kfree(tcd);
	}
}
EXPORT_SYMBOL(unregister_tape_dev);


static int __init tape_init(void)
{
	tape_class = class_create("tape390");

	return 0;
}

static void __exit tape_exit(void)
{
	class_destroy(tape_class);
	tape_class = NULL;
}

postcore_initcall(tape_init);
module_exit(tape_exit);