blob: 9b41c9bd805f561594fcc6fcf7d78923dad24490 [file] [log] [blame]
Mark M. Hoffman12364412005-07-15 21:38:08 -04001/*
2 hwmon.c - part of lm_sensors, Linux kernel modules for hardware monitoring
3
4 This file defines the sysfs class "hwmon", for use by sensors drivers.
5
6 Copyright (C) 2005 Mark M. Hoffman <mhoffman@lightlink.com>
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; version 2 of the License.
11*/
12
13#include <linux/module.h>
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/kdev_t.h>
17#include <linux/idr.h>
18#include <linux/hwmon.h>
19
20#define HWMON_ID_PREFIX "hwmon"
21#define HWMON_ID_FORMAT HWMON_ID_PREFIX "%d"
22
23static struct class *hwmon_class;
24
25static DEFINE_IDR(hwmon_idr);
26
27/**
28 * hwmon_device_register - register w/ hwmon sysfs class
29 * @dev: the device to register
30 *
31 * hwmon_device_unregister() must be called when the class device is no
32 * longer needed.
33 *
34 * Returns the pointer to the new struct class device.
35 */
36struct class_device *hwmon_device_register(struct device *dev)
37{
38 struct class_device *cdev;
39 int id;
40
41 if (idr_pre_get(&hwmon_idr, GFP_KERNEL) == 0)
42 return ERR_PTR(-ENOMEM);
43
44 if (idr_get_new(&hwmon_idr, NULL, &id) < 0)
45 return ERR_PTR(-ENOMEM);
46
47 id = id & MAX_ID_MASK;
48 cdev = class_device_create(hwmon_class, MKDEV(0,0), dev,
49 HWMON_ID_FORMAT, id);
50
51 if (IS_ERR(cdev))
52 idr_remove(&hwmon_idr, id);
53
54 return cdev;
55}
56
57/**
58 * hwmon_device_unregister - removes the previously registered class device
59 *
60 * @cdev: the class device to destroy
61 */
62void hwmon_device_unregister(struct class_device *cdev)
63{
64 int id;
65
66 if (sscanf(cdev->class_id, HWMON_ID_FORMAT, &id) == 1) {
67 class_device_unregister(cdev);
68 idr_remove(&hwmon_idr, id);
69 } else
70 dev_dbg(cdev->dev,
71 "hwmon_device_unregister() failed: bad class ID!\n");
72}
73
74static int __init hwmon_init(void)
75{
76 hwmon_class = class_create(THIS_MODULE, "hwmon");
77 if (IS_ERR(hwmon_class)) {
78 printk(KERN_ERR "hwmon.c: couldn't create sysfs class\n");
79 return PTR_ERR(hwmon_class);
80 }
81 return 0;
82}
83
84static void __exit hwmon_exit(void)
85{
86 class_destroy(hwmon_class);
87}
88
89module_init(hwmon_init);
90module_exit(hwmon_exit);
91
92EXPORT_SYMBOL_GPL(hwmon_device_register);
93EXPORT_SYMBOL_GPL(hwmon_device_unregister);
94
95MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
96MODULE_DESCRIPTION("hardware monitoring sysfs/class support");
97MODULE_LICENSE("GPL");
98