1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright IBM Corp. 2004
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Tape class device support
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Author: Stefan Bader <shbader@de.ibm.com>
8*4882a593Smuzhiyun * Based on simple class device code by Greg K-H
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #define KMSG_COMPONENT "tape"
12*4882a593Smuzhiyun #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun #include <linux/slab.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun #include "tape_class.h"
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>");
19*4882a593Smuzhiyun MODULE_DESCRIPTION(
20*4882a593Smuzhiyun "Copyright IBM Corp. 2004 All Rights Reserved.\n"
21*4882a593Smuzhiyun "tape_class.c"
22*4882a593Smuzhiyun );
23*4882a593Smuzhiyun MODULE_LICENSE("GPL");
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun static struct class *tape_class;
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun /*
28*4882a593Smuzhiyun * Register a tape device and return a pointer to the cdev structure.
29*4882a593Smuzhiyun *
30*4882a593Smuzhiyun * device
31*4882a593Smuzhiyun * The pointer to the struct device of the physical (base) device.
32*4882a593Smuzhiyun * drivername
33*4882a593Smuzhiyun * The pointer to the drivers name for it's character devices.
34*4882a593Smuzhiyun * dev
35*4882a593Smuzhiyun * The intended major/minor number. The major number may be 0 to
36*4882a593Smuzhiyun * get a dynamic major number.
37*4882a593Smuzhiyun * fops
38*4882a593Smuzhiyun * The pointer to the drivers file operations for the tape device.
39*4882a593Smuzhiyun * devname
40*4882a593Smuzhiyun * The pointer to the name of the character device.
41*4882a593Smuzhiyun */
register_tape_dev(struct device * device,dev_t dev,const struct file_operations * fops,char * device_name,char * mode_name)42*4882a593Smuzhiyun struct tape_class_device *register_tape_dev(
43*4882a593Smuzhiyun struct device * device,
44*4882a593Smuzhiyun dev_t dev,
45*4882a593Smuzhiyun const struct file_operations *fops,
46*4882a593Smuzhiyun char * device_name,
47*4882a593Smuzhiyun char * mode_name)
48*4882a593Smuzhiyun {
49*4882a593Smuzhiyun struct tape_class_device * tcd;
50*4882a593Smuzhiyun int rc;
51*4882a593Smuzhiyun char * s;
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun tcd = kzalloc(sizeof(struct tape_class_device), GFP_KERNEL);
54*4882a593Smuzhiyun if (!tcd)
55*4882a593Smuzhiyun return ERR_PTR(-ENOMEM);
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun strlcpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);
58*4882a593Smuzhiyun for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/'))
59*4882a593Smuzhiyun *s = '!';
60*4882a593Smuzhiyun strlcpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);
61*4882a593Smuzhiyun for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/'))
62*4882a593Smuzhiyun *s = '!';
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun tcd->char_device = cdev_alloc();
65*4882a593Smuzhiyun if (!tcd->char_device) {
66*4882a593Smuzhiyun rc = -ENOMEM;
67*4882a593Smuzhiyun goto fail_with_tcd;
68*4882a593Smuzhiyun }
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun tcd->char_device->owner = fops->owner;
71*4882a593Smuzhiyun tcd->char_device->ops = fops;
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun rc = cdev_add(tcd->char_device, dev, 1);
74*4882a593Smuzhiyun if (rc)
75*4882a593Smuzhiyun goto fail_with_cdev;
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun tcd->class_device = device_create(tape_class, device,
78*4882a593Smuzhiyun tcd->char_device->dev, NULL,
79*4882a593Smuzhiyun "%s", tcd->device_name);
80*4882a593Smuzhiyun rc = PTR_ERR_OR_ZERO(tcd->class_device);
81*4882a593Smuzhiyun if (rc)
82*4882a593Smuzhiyun goto fail_with_cdev;
83*4882a593Smuzhiyun rc = sysfs_create_link(
84*4882a593Smuzhiyun &device->kobj,
85*4882a593Smuzhiyun &tcd->class_device->kobj,
86*4882a593Smuzhiyun tcd->mode_name
87*4882a593Smuzhiyun );
88*4882a593Smuzhiyun if (rc)
89*4882a593Smuzhiyun goto fail_with_class_device;
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun return tcd;
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun fail_with_class_device:
94*4882a593Smuzhiyun device_destroy(tape_class, tcd->char_device->dev);
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun fail_with_cdev:
97*4882a593Smuzhiyun cdev_del(tcd->char_device);
98*4882a593Smuzhiyun
99*4882a593Smuzhiyun fail_with_tcd:
100*4882a593Smuzhiyun kfree(tcd);
101*4882a593Smuzhiyun
102*4882a593Smuzhiyun return ERR_PTR(rc);
103*4882a593Smuzhiyun }
104*4882a593Smuzhiyun EXPORT_SYMBOL(register_tape_dev);
105*4882a593Smuzhiyun
unregister_tape_dev(struct device * device,struct tape_class_device * tcd)106*4882a593Smuzhiyun void unregister_tape_dev(struct device *device, struct tape_class_device *tcd)
107*4882a593Smuzhiyun {
108*4882a593Smuzhiyun if (tcd != NULL && !IS_ERR(tcd)) {
109*4882a593Smuzhiyun sysfs_remove_link(&device->kobj, tcd->mode_name);
110*4882a593Smuzhiyun device_destroy(tape_class, tcd->char_device->dev);
111*4882a593Smuzhiyun cdev_del(tcd->char_device);
112*4882a593Smuzhiyun kfree(tcd);
113*4882a593Smuzhiyun }
114*4882a593Smuzhiyun }
115*4882a593Smuzhiyun EXPORT_SYMBOL(unregister_tape_dev);
116*4882a593Smuzhiyun
117*4882a593Smuzhiyun
tape_init(void)118*4882a593Smuzhiyun static int __init tape_init(void)
119*4882a593Smuzhiyun {
120*4882a593Smuzhiyun tape_class = class_create(THIS_MODULE, "tape390");
121*4882a593Smuzhiyun
122*4882a593Smuzhiyun return 0;
123*4882a593Smuzhiyun }
124*4882a593Smuzhiyun
tape_exit(void)125*4882a593Smuzhiyun static void __exit tape_exit(void)
126*4882a593Smuzhiyun {
127*4882a593Smuzhiyun class_destroy(tape_class);
128*4882a593Smuzhiyun tape_class = NULL;
129*4882a593Smuzhiyun }
130*4882a593Smuzhiyun
131*4882a593Smuzhiyun postcore_initcall(tape_init);
132*4882a593Smuzhiyun module_exit(tape_exit);
133