blob: 04aaa634723467ac90cbd8bd4d41419bdfc89647 [file] [log] [blame]
Alessandro Zummo0c86edc2006-03-27 01:16:37 -08001/*
2 * RTC subsystem, base class
3 *
4 * Copyright (C) 2005 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 *
7 * class skeleton from drivers/hwmon/hwmon.c
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12*/
13
14#include <linux/module.h>
15#include <linux/rtc.h>
16#include <linux/kdev_t.h>
17#include <linux/idr.h>
18
19static DEFINE_IDR(rtc_idr);
20static DEFINE_MUTEX(idr_lock);
21struct class *rtc_class;
22
23static void rtc_device_release(struct class_device *class_dev)
24{
25 struct rtc_device *rtc = to_rtc_device(class_dev);
26 mutex_lock(&idr_lock);
27 idr_remove(&rtc_idr, rtc->id);
28 mutex_unlock(&idr_lock);
29 kfree(rtc);
30}
31
32/**
33 * rtc_device_register - register w/ RTC class
34 * @dev: the device to register
35 *
36 * rtc_device_unregister() must be called when the class device is no
37 * longer needed.
38 *
39 * Returns the pointer to the new struct class device.
40 */
41struct rtc_device *rtc_device_register(const char *name, struct device *dev,
David Brownellff8371a2006-09-30 23:28:17 -070042 const struct rtc_class_ops *ops,
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080043 struct module *owner)
44{
45 struct rtc_device *rtc;
46 int id, err;
47
48 if (idr_pre_get(&rtc_idr, GFP_KERNEL) == 0) {
49 err = -ENOMEM;
50 goto exit;
51 }
52
53
54 mutex_lock(&idr_lock);
55 err = idr_get_new(&rtc_idr, NULL, &id);
56 mutex_unlock(&idr_lock);
57
58 if (err < 0)
59 goto exit;
60
61 id = id & MAX_ID_MASK;
62
63 rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL);
64 if (rtc == NULL) {
65 err = -ENOMEM;
66 goto exit_idr;
67 }
68
69 rtc->id = id;
70 rtc->ops = ops;
71 rtc->owner = owner;
Alessandro Zummo110d6932006-06-25 05:48:20 -070072 rtc->max_user_freq = 64;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080073 rtc->class_dev.dev = dev;
74 rtc->class_dev.class = rtc_class;
75 rtc->class_dev.release = rtc_device_release;
76
77 mutex_init(&rtc->ops_lock);
78 spin_lock_init(&rtc->irq_lock);
79 spin_lock_init(&rtc->irq_task_lock);
80
81 strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE);
82 snprintf(rtc->class_dev.class_id, BUS_ID_SIZE, "rtc%d", id);
83
84 err = class_device_register(&rtc->class_dev);
85 if (err)
86 goto exit_kfree;
87
88 dev_info(dev, "rtc core: registered %s as %s\n",
89 rtc->name, rtc->class_dev.class_id);
90
91 return rtc;
92
93exit_kfree:
94 kfree(rtc);
95
96exit_idr:
Sonny Rao6ac12df2006-06-27 02:54:06 -070097 mutex_lock(&idr_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080098 idr_remove(&rtc_idr, id);
Sonny Rao6ac12df2006-06-27 02:54:06 -070099 mutex_unlock(&idr_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800100
101exit:
Alessandro Zummod1d65b72006-04-10 22:54:45 -0700102 dev_err(dev, "rtc core: unable to register %s, err = %d\n",
103 name, err);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800104 return ERR_PTR(err);
105}
106EXPORT_SYMBOL_GPL(rtc_device_register);
107
108
109/**
110 * rtc_device_unregister - removes the previously registered RTC class device
111 *
112 * @rtc: the RTC class device to destroy
113 */
114void rtc_device_unregister(struct rtc_device *rtc)
115{
David Brownelle109ebd2007-02-28 20:12:40 -0800116 if (class_device_get(&rtc->class_dev) != NULL) {
117 mutex_lock(&rtc->ops_lock);
118 /* remove innards of this RTC, then disable it, before
119 * letting any rtc_class_open() users access it again
120 */
121 class_device_unregister(&rtc->class_dev);
122 rtc->ops = NULL;
123 mutex_unlock(&rtc->ops_lock);
124 class_device_put(&rtc->class_dev);
125 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800126}
127EXPORT_SYMBOL_GPL(rtc_device_unregister);
128
129int rtc_interface_register(struct class_interface *intf)
130{
131 intf->class = rtc_class;
132 return class_interface_register(intf);
133}
134EXPORT_SYMBOL_GPL(rtc_interface_register);
135
136static int __init rtc_init(void)
137{
138 rtc_class = class_create(THIS_MODULE, "rtc");
139 if (IS_ERR(rtc_class)) {
140 printk(KERN_ERR "%s: couldn't create class\n", __FILE__);
141 return PTR_ERR(rtc_class);
142 }
143 return 0;
144}
145
146static void __exit rtc_exit(void)
147{
148 class_destroy(rtc_class);
149}
150
David Brownell818a8672006-09-30 23:28:15 -0700151subsys_initcall(rtc_init);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800152module_exit(rtc_exit);
153
David Brownell818a8672006-09-30 23:28:15 -0700154MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800155MODULE_DESCRIPTION("RTC class support");
156MODULE_LICENSE("GPL");