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0c86edc0 AZ |
1 | /* |
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> | |
5a0e3ad6 | 18 | #include <linux/slab.h> |
6610e089 | 19 | #include <linux/workqueue.h> |
0c86edc0 | 20 | |
5726fb20 DB |
21 | #include "rtc-core.h" |
22 | ||
23 | ||
0c86edc0 AZ |
24 | static DEFINE_IDR(rtc_idr); |
25 | static DEFINE_MUTEX(idr_lock); | |
26 | struct class *rtc_class; | |
27 | ||
cd966209 | 28 | static void rtc_device_release(struct device *dev) |
0c86edc0 | 29 | { |
cd966209 | 30 | struct rtc_device *rtc = to_rtc_device(dev); |
0c86edc0 AZ |
31 | mutex_lock(&idr_lock); |
32 | idr_remove(&rtc_idr, rtc->id); | |
33 | mutex_unlock(&idr_lock); | |
34 | kfree(rtc); | |
35 | } | |
36 | ||
7ca1d488 DB |
37 | #if defined(CONFIG_PM) && defined(CONFIG_RTC_HCTOSYS_DEVICE) |
38 | ||
39 | /* | |
40 | * On suspend(), measure the delta between one RTC and the | |
41 | * system's wall clock; restore it on resume(). | |
42 | */ | |
43 | ||
44 | static struct timespec delta; | |
45 | static time_t oldtime; | |
46 | ||
47 | static int rtc_suspend(struct device *dev, pm_message_t mesg) | |
48 | { | |
49 | struct rtc_device *rtc = to_rtc_device(dev); | |
50 | struct rtc_time tm; | |
2c6b47de | 51 | struct timespec ts = current_kernel_time(); |
7ca1d488 | 52 | |
d4afc76c | 53 | if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0) |
7ca1d488 DB |
54 | return 0; |
55 | ||
56 | rtc_read_time(rtc, &tm); | |
57 | rtc_tm_to_time(&tm, &oldtime); | |
58 | ||
59 | /* RTC precision is 1 second; adjust delta for avg 1/2 sec err */ | |
60 | set_normalized_timespec(&delta, | |
2c6b47de JS |
61 | ts.tv_sec - oldtime, |
62 | ts.tv_nsec - (NSEC_PER_SEC >> 1)); | |
7ca1d488 DB |
63 | |
64 | return 0; | |
65 | } | |
66 | ||
67 | static int rtc_resume(struct device *dev) | |
68 | { | |
69 | struct rtc_device *rtc = to_rtc_device(dev); | |
70 | struct rtc_time tm; | |
71 | time_t newtime; | |
72 | struct timespec time; | |
73 | ||
d4afc76c | 74 | if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0) |
7ca1d488 DB |
75 | return 0; |
76 | ||
77 | rtc_read_time(rtc, &tm); | |
78 | if (rtc_valid_tm(&tm) != 0) { | |
d4afc76c | 79 | pr_debug("%s: bogus resume time\n", dev_name(&rtc->dev)); |
7ca1d488 DB |
80 | return 0; |
81 | } | |
82 | rtc_tm_to_time(&tm, &newtime); | |
83 | if (newtime <= oldtime) { | |
84 | if (newtime < oldtime) | |
d4afc76c | 85 | pr_debug("%s: time travel!\n", dev_name(&rtc->dev)); |
7ca1d488 DB |
86 | return 0; |
87 | } | |
88 | ||
89 | /* restore wall clock using delta against this RTC; | |
90 | * adjust again for avg 1/2 second RTC sampling error | |
91 | */ | |
92 | set_normalized_timespec(&time, | |
93 | newtime + delta.tv_sec, | |
94 | (NSEC_PER_SEC >> 1) + delta.tv_nsec); | |
95 | do_settimeofday(&time); | |
96 | ||
97 | return 0; | |
98 | } | |
99 | ||
100 | #else | |
101 | #define rtc_suspend NULL | |
102 | #define rtc_resume NULL | |
103 | #endif | |
104 | ||
105 | ||
0c86edc0 AZ |
106 | /** |
107 | * rtc_device_register - register w/ RTC class | |
108 | * @dev: the device to register | |
109 | * | |
110 | * rtc_device_unregister() must be called when the class device is no | |
111 | * longer needed. | |
112 | * | |
113 | * Returns the pointer to the new struct class device. | |
114 | */ | |
115 | struct rtc_device *rtc_device_register(const char *name, struct device *dev, | |
ff8371ac | 116 | const struct rtc_class_ops *ops, |
0c86edc0 AZ |
117 | struct module *owner) |
118 | { | |
119 | struct rtc_device *rtc; | |
120 | int id, err; | |
121 | ||
122 | if (idr_pre_get(&rtc_idr, GFP_KERNEL) == 0) { | |
123 | err = -ENOMEM; | |
124 | goto exit; | |
125 | } | |
126 | ||
127 | ||
128 | mutex_lock(&idr_lock); | |
129 | err = idr_get_new(&rtc_idr, NULL, &id); | |
130 | mutex_unlock(&idr_lock); | |
131 | ||
132 | if (err < 0) | |
133 | goto exit; | |
134 | ||
135 | id = id & MAX_ID_MASK; | |
136 | ||
137 | rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL); | |
138 | if (rtc == NULL) { | |
139 | err = -ENOMEM; | |
140 | goto exit_idr; | |
141 | } | |
142 | ||
143 | rtc->id = id; | |
144 | rtc->ops = ops; | |
145 | rtc->owner = owner; | |
110d693d | 146 | rtc->max_user_freq = 64; |
cd966209 DB |
147 | rtc->dev.parent = dev; |
148 | rtc->dev.class = rtc_class; | |
149 | rtc->dev.release = rtc_device_release; | |
0c86edc0 AZ |
150 | |
151 | mutex_init(&rtc->ops_lock); | |
152 | spin_lock_init(&rtc->irq_lock); | |
153 | spin_lock_init(&rtc->irq_task_lock); | |
d691eb90 | 154 | init_waitqueue_head(&rtc->irq_queue); |
0c86edc0 | 155 | |
6610e089 JS |
156 | /* Init timerqueue */ |
157 | timerqueue_init_head(&rtc->timerqueue); | |
96c8f06a | 158 | INIT_WORK(&rtc->irqwork, rtc_timer_do_work); |
6610e089 | 159 | /* Init aie timer */ |
96c8f06a | 160 | rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc); |
6610e089 | 161 | /* Init uie timer */ |
96c8f06a | 162 | rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc); |
6610e089 JS |
163 | /* Init pie timer */ |
164 | hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
165 | rtc->pie_timer.function = rtc_pie_update_irq; | |
166 | rtc->pie_enabled = 0; | |
167 | ||
0c86edc0 | 168 | strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE); |
d4afc76c | 169 | dev_set_name(&rtc->dev, "rtc%d", id); |
0c86edc0 | 170 | |
cb3a58d2 DB |
171 | rtc_dev_prepare(rtc); |
172 | ||
cd966209 | 173 | err = device_register(&rtc->dev); |
59cca865 VK |
174 | if (err) { |
175 | put_device(&rtc->dev); | |
0c86edc0 | 176 | goto exit_kfree; |
59cca865 | 177 | } |
0c86edc0 | 178 | |
5726fb20 | 179 | rtc_dev_add_device(rtc); |
446ecbd9 | 180 | rtc_sysfs_add_device(rtc); |
7d9f99ec | 181 | rtc_proc_add_device(rtc); |
5726fb20 | 182 | |
0c86edc0 | 183 | dev_info(dev, "rtc core: registered %s as %s\n", |
d4afc76c | 184 | rtc->name, dev_name(&rtc->dev)); |
0c86edc0 AZ |
185 | |
186 | return rtc; | |
187 | ||
188 | exit_kfree: | |
189 | kfree(rtc); | |
190 | ||
191 | exit_idr: | |
6ac12dfe | 192 | mutex_lock(&idr_lock); |
0c86edc0 | 193 | idr_remove(&rtc_idr, id); |
6ac12dfe | 194 | mutex_unlock(&idr_lock); |
0c86edc0 AZ |
195 | |
196 | exit: | |
d1d65b77 AZ |
197 | dev_err(dev, "rtc core: unable to register %s, err = %d\n", |
198 | name, err); | |
0c86edc0 AZ |
199 | return ERR_PTR(err); |
200 | } | |
201 | EXPORT_SYMBOL_GPL(rtc_device_register); | |
202 | ||
203 | ||
204 | /** | |
205 | * rtc_device_unregister - removes the previously registered RTC class device | |
206 | * | |
207 | * @rtc: the RTC class device to destroy | |
208 | */ | |
209 | void rtc_device_unregister(struct rtc_device *rtc) | |
210 | { | |
cd966209 | 211 | if (get_device(&rtc->dev) != NULL) { |
e109ebd1 DB |
212 | mutex_lock(&rtc->ops_lock); |
213 | /* remove innards of this RTC, then disable it, before | |
214 | * letting any rtc_class_open() users access it again | |
215 | */ | |
446ecbd9 | 216 | rtc_sysfs_del_device(rtc); |
5726fb20 | 217 | rtc_dev_del_device(rtc); |
7d9f99ec | 218 | rtc_proc_del_device(rtc); |
cd966209 | 219 | device_unregister(&rtc->dev); |
e109ebd1 DB |
220 | rtc->ops = NULL; |
221 | mutex_unlock(&rtc->ops_lock); | |
cd966209 | 222 | put_device(&rtc->dev); |
e109ebd1 | 223 | } |
0c86edc0 AZ |
224 | } |
225 | EXPORT_SYMBOL_GPL(rtc_device_unregister); | |
226 | ||
0c86edc0 AZ |
227 | static int __init rtc_init(void) |
228 | { | |
229 | rtc_class = class_create(THIS_MODULE, "rtc"); | |
230 | if (IS_ERR(rtc_class)) { | |
231 | printk(KERN_ERR "%s: couldn't create class\n", __FILE__); | |
232 | return PTR_ERR(rtc_class); | |
233 | } | |
7ca1d488 DB |
234 | rtc_class->suspend = rtc_suspend; |
235 | rtc_class->resume = rtc_resume; | |
5726fb20 | 236 | rtc_dev_init(); |
446ecbd9 | 237 | rtc_sysfs_init(rtc_class); |
0c86edc0 AZ |
238 | return 0; |
239 | } | |
240 | ||
241 | static void __exit rtc_exit(void) | |
242 | { | |
5726fb20 | 243 | rtc_dev_exit(); |
0c86edc0 | 244 | class_destroy(rtc_class); |
2a7a06a0 | 245 | idr_destroy(&rtc_idr); |
0c86edc0 AZ |
246 | } |
247 | ||
818a8674 | 248 | subsys_initcall(rtc_init); |
0c86edc0 AZ |
249 | module_exit(rtc_exit); |
250 | ||
818a8674 | 251 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); |
0c86edc0 AZ |
252 | MODULE_DESCRIPTION("RTC class support"); |
253 | MODULE_LICENSE("GPL"); |