Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...
[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 = kmalloc(sizeof(struct tape_class_device), GFP_KERNEL);
48         if (!tcd)
49                 return ERR_PTR(-ENOMEM);
50
51         memset(tcd, 0, sizeof(struct tape_class_device));
52         strncpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);
53         for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/'))
54                 *s = '!';
55         strncpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);
56         for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/'))
57                 *s = '!';
58
59         tcd->char_device = cdev_alloc();
60         if (!tcd->char_device) {
61                 rc = -ENOMEM;
62                 goto fail_with_tcd;
63         }
64
65         tcd->char_device->owner = fops->owner;
66         tcd->char_device->ops   = fops;
67         tcd->char_device->dev   = dev;
68
69         rc = cdev_add(tcd->char_device, tcd->char_device->dev, 1);
70         if (rc)
71                 goto fail_with_cdev;
72
73         tcd->class_device = class_device_create(
74                                 tape_class,
75                                 NULL,
76                                 tcd->char_device->dev,
77                                 device,
78                                 "%s", tcd->device_name
79                         );
80         sysfs_create_link(
81                 &device->kobj,
82                 &tcd->class_device->kobj,
83                 tcd->mode_name
84         );
85
86         return tcd;
87
88 fail_with_cdev:
89         cdev_del(tcd->char_device);
90
91 fail_with_tcd:
92         kfree(tcd);
93
94         return ERR_PTR(rc);
95 }
96 EXPORT_SYMBOL(register_tape_dev);
97
98 void unregister_tape_dev(struct tape_class_device *tcd)
99 {
100         if (tcd != NULL && !IS_ERR(tcd)) {
101                 sysfs_remove_link(
102                         &tcd->class_device->dev->kobj,
103                         tcd->mode_name
104                 );
105                 class_device_destroy(tape_class, tcd->char_device->dev);
106                 cdev_del(tcd->char_device);
107                 kfree(tcd);
108         }
109 }
110 EXPORT_SYMBOL(unregister_tape_dev);
111
112
113 static int __init tape_init(void)
114 {
115         tape_class = class_create(THIS_MODULE, "tape390");
116
117         return 0;
118 }
119
120 static void __exit tape_exit(void)
121 {
122         class_destroy(tape_class);
123         tape_class = NULL;
124 }
125
126 postcore_initcall(tape_init);
127 module_exit(tape_exit);