Merge mulgrave-w:git/scsi-misc-2.6
[linux-2.6] / drivers / s390 / char / tape_class.c
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
12 MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>");
13 MODULE_DESCRIPTION(
14         "(C) Copyright IBM Corp. 2004   All Rights Reserved.\n"
15         "tape_class.c"
16 );
17 MODULE_LICENSE("GPL");
18
19 static 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  */
36 struct tape_class_device *register_tape_dev(
37         struct device *         device,
38         dev_t                   dev,
39         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
92 fail_with_class_device:
93         class_device_destroy(tape_class, tcd->char_device->dev);
94
95 fail_with_cdev:
96         cdev_del(tcd->char_device);
97
98 fail_with_tcd:
99         kfree(tcd);
100
101         return ERR_PTR(rc);
102 }
103 EXPORT_SYMBOL(register_tape_dev);
104
105 void 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 }
117 EXPORT_SYMBOL(unregister_tape_dev);
118
119
120 static int __init tape_init(void)
121 {
122         tape_class = class_create(THIS_MODULE, "tape390");
123
124         return 0;
125 }
126
127 static void __exit tape_exit(void)
128 {
129         class_destroy(tape_class);
130         tape_class = NULL;
131 }
132
133 postcore_initcall(tape_init);
134 module_exit(tape_exit);