tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 = device_create(tape_class, device,
73 tcd->char_device->dev, NULL,
74 "%s", tcd->device_name);
75 rc = IS_ERR(tcd->class_device) ? PTR_ERR(tcd->class_device) : 0;
76 if (rc)
77 goto fail_with_cdev;
78 rc = sysfs_create_link(
79 &device->kobj,
80 &tcd->class_device->kobj,
81 tcd->mode_name
82 );
83 if (rc)
84 goto fail_with_class_device;
85
86 return tcd;
87
88fail_with_class_device:
89 device_destroy(tape_class, tcd->char_device->dev);
90
91fail_with_cdev:
92 cdev_del(tcd->char_device);
93
94fail_with_tcd:
95 kfree(tcd);
96
97 return ERR_PTR(rc);
98}
99EXPORT_SYMBOL(register_tape_dev);
100
101void unregister_tape_dev(struct device *device, struct tape_class_device *tcd)
102{
103 if (tcd != NULL && !IS_ERR(tcd)) {
104 sysfs_remove_link(&device->kobj, tcd->mode_name);
105 device_destroy(tape_class, tcd->char_device->dev);
106 cdev_del(tcd->char_device);
107 kfree(tcd);
108 }
109}
110EXPORT_SYMBOL(unregister_tape_dev);
111
112
113static int __init tape_init(void)
114{
115 tape_class = class_create(THIS_MODULE, "tape390");
116
117 return 0;
118}
119
120static void __exit tape_exit(void)
121{
122 class_destroy(tape_class);
123 tape_class = NULL;
124}
125
126postcore_initcall(tape_init);
127module_exit(tape_exit);