Commit | Line | Data |
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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 | ||
c100a5e0 JH |
14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
15 | ||
0c86edc0 AZ |
16 | #include <linux/module.h> |
17 | #include <linux/rtc.h> | |
18 | #include <linux/kdev_t.h> | |
19 | #include <linux/idr.h> | |
5a0e3ad6 | 20 | #include <linux/slab.h> |
6610e089 | 21 | #include <linux/workqueue.h> |
0c86edc0 | 22 | |
5726fb20 DB |
23 | #include "rtc-core.h" |
24 | ||
25 | ||
6d03d06d | 26 | static DEFINE_IDA(rtc_ida); |
0c86edc0 AZ |
27 | struct class *rtc_class; |
28 | ||
cd966209 | 29 | static void rtc_device_release(struct device *dev) |
0c86edc0 | 30 | { |
cd966209 | 31 | struct rtc_device *rtc = to_rtc_device(dev); |
6d03d06d | 32 | ida_simple_remove(&rtc_ida, rtc->id); |
0c86edc0 AZ |
33 | kfree(rtc); |
34 | } | |
35 | ||
4c24e29e DF |
36 | #ifdef CONFIG_RTC_HCTOSYS_DEVICE |
37 | /* Result of the last RTC to system clock attempt. */ | |
38 | int rtc_hctosys_ret = -ENODEV; | |
39 | #endif | |
7ca1d488 | 40 | |
92e7f04a | 41 | #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE) |
7ca1d488 DB |
42 | /* |
43 | * On suspend(), measure the delta between one RTC and the | |
44 | * system's wall clock; restore it on resume(). | |
45 | */ | |
46 | ||
3dcad5ff JS |
47 | static struct timespec old_rtc, old_system, old_delta; |
48 | ||
7ca1d488 | 49 | |
92e7f04a | 50 | static int rtc_suspend(struct device *dev) |
7ca1d488 DB |
51 | { |
52 | struct rtc_device *rtc = to_rtc_device(dev); | |
53 | struct rtc_time tm; | |
3dcad5ff | 54 | struct timespec delta, delta_delta; |
9ecf37eb FT |
55 | |
56 | if (has_persistent_clock()) | |
57 | return 0; | |
58 | ||
d4afc76c | 59 | if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0) |
7ca1d488 DB |
60 | return 0; |
61 | ||
3dcad5ff | 62 | /* snapshot the current RTC and system time at suspend*/ |
7ca1d488 | 63 | rtc_read_time(rtc, &tm); |
3dcad5ff JS |
64 | getnstimeofday(&old_system); |
65 | rtc_tm_to_time(&tm, &old_rtc.tv_sec); | |
66 | ||
67 | ||
68 | /* | |
69 | * To avoid drift caused by repeated suspend/resumes, | |
70 | * which each can add ~1 second drift error, | |
71 | * try to compensate so the difference in system time | |
72 | * and rtc time stays close to constant. | |
73 | */ | |
74 | delta = timespec_sub(old_system, old_rtc); | |
75 | delta_delta = timespec_sub(delta, old_delta); | |
6a8943d9 | 76 | if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) { |
3dcad5ff JS |
77 | /* |
78 | * if delta_delta is too large, assume time correction | |
79 | * has occured and set old_delta to the current delta. | |
80 | */ | |
81 | old_delta = delta; | |
82 | } else { | |
83 | /* Otherwise try to adjust old_system to compensate */ | |
84 | old_system = timespec_sub(old_system, delta_delta); | |
85 | } | |
7ca1d488 | 86 | |
7ca1d488 DB |
87 | return 0; |
88 | } | |
89 | ||
90 | static int rtc_resume(struct device *dev) | |
91 | { | |
92 | struct rtc_device *rtc = to_rtc_device(dev); | |
93 | struct rtc_time tm; | |
3dcad5ff JS |
94 | struct timespec new_system, new_rtc; |
95 | struct timespec sleep_time; | |
7ca1d488 | 96 | |
9ecf37eb FT |
97 | if (has_persistent_clock()) |
98 | return 0; | |
99 | ||
4c24e29e | 100 | rtc_hctosys_ret = -ENODEV; |
d4afc76c | 101 | if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0) |
7ca1d488 DB |
102 | return 0; |
103 | ||
3dcad5ff JS |
104 | /* snapshot the current rtc and system time at resume */ |
105 | getnstimeofday(&new_system); | |
7ca1d488 DB |
106 | rtc_read_time(rtc, &tm); |
107 | if (rtc_valid_tm(&tm) != 0) { | |
d4afc76c | 108 | pr_debug("%s: bogus resume time\n", dev_name(&rtc->dev)); |
7ca1d488 DB |
109 | return 0; |
110 | } | |
3dcad5ff JS |
111 | rtc_tm_to_time(&tm, &new_rtc.tv_sec); |
112 | new_rtc.tv_nsec = 0; | |
113 | ||
6a8943d9 AH |
114 | if (new_rtc.tv_sec < old_rtc.tv_sec) { |
115 | pr_debug("%s: time travel!\n", dev_name(&rtc->dev)); | |
7ca1d488 DB |
116 | return 0; |
117 | } | |
118 | ||
3dcad5ff JS |
119 | /* calculate the RTC time delta (sleep time)*/ |
120 | sleep_time = timespec_sub(new_rtc, old_rtc); | |
121 | ||
122 | /* | |
123 | * Since these RTC suspend/resume handlers are not called | |
124 | * at the very end of suspend or the start of resume, | |
125 | * some run-time may pass on either sides of the sleep time | |
126 | * so subtract kernel run-time between rtc_suspend to rtc_resume | |
127 | * to keep things accurate. | |
128 | */ | |
129 | sleep_time = timespec_sub(sleep_time, | |
130 | timespec_sub(new_system, old_system)); | |
7ca1d488 | 131 | |
6a8943d9 AH |
132 | if (sleep_time.tv_sec >= 0) |
133 | timekeeping_inject_sleeptime(&sleep_time); | |
4c24e29e | 134 | rtc_hctosys_ret = 0; |
7ca1d488 DB |
135 | return 0; |
136 | } | |
137 | ||
92e7f04a SK |
138 | static SIMPLE_DEV_PM_OPS(rtc_class_dev_pm_ops, rtc_suspend, rtc_resume); |
139 | #define RTC_CLASS_DEV_PM_OPS (&rtc_class_dev_pm_ops) | |
7ca1d488 | 140 | #else |
92e7f04a | 141 | #define RTC_CLASS_DEV_PM_OPS NULL |
7ca1d488 DB |
142 | #endif |
143 | ||
144 | ||
0c86edc0 AZ |
145 | /** |
146 | * rtc_device_register - register w/ RTC class | |
147 | * @dev: the device to register | |
148 | * | |
149 | * rtc_device_unregister() must be called when the class device is no | |
150 | * longer needed. | |
151 | * | |
152 | * Returns the pointer to the new struct class device. | |
153 | */ | |
154 | struct rtc_device *rtc_device_register(const char *name, struct device *dev, | |
ff8371ac | 155 | const struct rtc_class_ops *ops, |
0c86edc0 AZ |
156 | struct module *owner) |
157 | { | |
158 | struct rtc_device *rtc; | |
f44f7f96 | 159 | struct rtc_wkalrm alrm; |
0c86edc0 AZ |
160 | int id, err; |
161 | ||
6d03d06d JC |
162 | id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL); |
163 | if (id < 0) { | |
164 | err = id; | |
0c86edc0 AZ |
165 | goto exit; |
166 | } | |
167 | ||
0c86edc0 AZ |
168 | rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL); |
169 | if (rtc == NULL) { | |
170 | err = -ENOMEM; | |
6d03d06d | 171 | goto exit_ida; |
0c86edc0 AZ |
172 | } |
173 | ||
174 | rtc->id = id; | |
175 | rtc->ops = ops; | |
176 | rtc->owner = owner; | |
83a06bf5 | 177 | rtc->irq_freq = 1; |
110d693d | 178 | rtc->max_user_freq = 64; |
cd966209 DB |
179 | rtc->dev.parent = dev; |
180 | rtc->dev.class = rtc_class; | |
181 | rtc->dev.release = rtc_device_release; | |
0c86edc0 AZ |
182 | |
183 | mutex_init(&rtc->ops_lock); | |
184 | spin_lock_init(&rtc->irq_lock); | |
185 | spin_lock_init(&rtc->irq_task_lock); | |
d691eb90 | 186 | init_waitqueue_head(&rtc->irq_queue); |
0c86edc0 | 187 | |
6610e089 JS |
188 | /* Init timerqueue */ |
189 | timerqueue_init_head(&rtc->timerqueue); | |
96c8f06a | 190 | INIT_WORK(&rtc->irqwork, rtc_timer_do_work); |
6610e089 | 191 | /* Init aie timer */ |
96c8f06a | 192 | rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc); |
6610e089 | 193 | /* Init uie timer */ |
96c8f06a | 194 | rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc); |
6610e089 JS |
195 | /* Init pie timer */ |
196 | hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
197 | rtc->pie_timer.function = rtc_pie_update_irq; | |
198 | rtc->pie_enabled = 0; | |
199 | ||
f44f7f96 JS |
200 | /* Check to see if there is an ALARM already set in hw */ |
201 | err = __rtc_read_alarm(rtc, &alrm); | |
202 | ||
203 | if (!err && !rtc_valid_tm(&alrm.time)) | |
f6d5b331 | 204 | rtc_initialize_alarm(rtc, &alrm); |
f44f7f96 | 205 | |
0c86edc0 | 206 | strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE); |
d4afc76c | 207 | dev_set_name(&rtc->dev, "rtc%d", id); |
0c86edc0 | 208 | |
cb3a58d2 DB |
209 | rtc_dev_prepare(rtc); |
210 | ||
cd966209 | 211 | err = device_register(&rtc->dev); |
59cca865 VK |
212 | if (err) { |
213 | put_device(&rtc->dev); | |
0c86edc0 | 214 | goto exit_kfree; |
59cca865 | 215 | } |
0c86edc0 | 216 | |
5726fb20 | 217 | rtc_dev_add_device(rtc); |
446ecbd9 | 218 | rtc_sysfs_add_device(rtc); |
7d9f99ec | 219 | rtc_proc_add_device(rtc); |
5726fb20 | 220 | |
0c86edc0 | 221 | dev_info(dev, "rtc core: registered %s as %s\n", |
d4afc76c | 222 | rtc->name, dev_name(&rtc->dev)); |
0c86edc0 AZ |
223 | |
224 | return rtc; | |
225 | ||
226 | exit_kfree: | |
227 | kfree(rtc); | |
228 | ||
6d03d06d JC |
229 | exit_ida: |
230 | ida_simple_remove(&rtc_ida, id); | |
0c86edc0 AZ |
231 | |
232 | exit: | |
d1d65b77 AZ |
233 | dev_err(dev, "rtc core: unable to register %s, err = %d\n", |
234 | name, err); | |
0c86edc0 AZ |
235 | return ERR_PTR(err); |
236 | } | |
237 | EXPORT_SYMBOL_GPL(rtc_device_register); | |
238 | ||
239 | ||
240 | /** | |
241 | * rtc_device_unregister - removes the previously registered RTC class device | |
242 | * | |
243 | * @rtc: the RTC class device to destroy | |
244 | */ | |
245 | void rtc_device_unregister(struct rtc_device *rtc) | |
246 | { | |
cd966209 | 247 | if (get_device(&rtc->dev) != NULL) { |
e109ebd1 DB |
248 | mutex_lock(&rtc->ops_lock); |
249 | /* remove innards of this RTC, then disable it, before | |
250 | * letting any rtc_class_open() users access it again | |
251 | */ | |
446ecbd9 | 252 | rtc_sysfs_del_device(rtc); |
5726fb20 | 253 | rtc_dev_del_device(rtc); |
7d9f99ec | 254 | rtc_proc_del_device(rtc); |
cd966209 | 255 | device_unregister(&rtc->dev); |
e109ebd1 DB |
256 | rtc->ops = NULL; |
257 | mutex_unlock(&rtc->ops_lock); | |
cd966209 | 258 | put_device(&rtc->dev); |
e109ebd1 | 259 | } |
0c86edc0 AZ |
260 | } |
261 | EXPORT_SYMBOL_GPL(rtc_device_unregister); | |
262 | ||
3e217b66 JH |
263 | static void devm_rtc_device_release(struct device *dev, void *res) |
264 | { | |
265 | struct rtc_device *rtc = *(struct rtc_device **)res; | |
266 | ||
267 | rtc_device_unregister(rtc); | |
268 | } | |
269 | ||
270 | static int devm_rtc_device_match(struct device *dev, void *res, void *data) | |
271 | { | |
272 | struct rtc **r = res; | |
273 | ||
274 | return *r == data; | |
275 | } | |
276 | ||
277 | /** | |
278 | * devm_rtc_device_register - resource managed rtc_device_register() | |
3e217b66 | 279 | * @dev: the device to register |
6636a994 | 280 | * @name: the name of the device |
3e217b66 JH |
281 | * @ops: the rtc operations structure |
282 | * @owner: the module owner | |
283 | * | |
284 | * @return a struct rtc on success, or an ERR_PTR on error | |
285 | * | |
286 | * Managed rtc_device_register(). The rtc_device returned from this function | |
287 | * are automatically freed on driver detach. See rtc_device_register() | |
288 | * for more information. | |
289 | */ | |
290 | ||
6636a994 JH |
291 | struct rtc_device *devm_rtc_device_register(struct device *dev, |
292 | const char *name, | |
3e217b66 JH |
293 | const struct rtc_class_ops *ops, |
294 | struct module *owner) | |
295 | { | |
296 | struct rtc_device **ptr, *rtc; | |
297 | ||
298 | ptr = devres_alloc(devm_rtc_device_release, sizeof(*ptr), GFP_KERNEL); | |
299 | if (!ptr) | |
300 | return ERR_PTR(-ENOMEM); | |
301 | ||
302 | rtc = rtc_device_register(name, dev, ops, owner); | |
303 | if (!IS_ERR(rtc)) { | |
304 | *ptr = rtc; | |
305 | devres_add(dev, ptr); | |
306 | } else { | |
307 | devres_free(ptr); | |
308 | } | |
309 | ||
310 | return rtc; | |
311 | } | |
312 | EXPORT_SYMBOL_GPL(devm_rtc_device_register); | |
313 | ||
314 | /** | |
315 | * devm_rtc_device_unregister - resource managed devm_rtc_device_unregister() | |
316 | * @dev: the device to unregister | |
317 | * @rtc: the RTC class device to unregister | |
318 | * | |
319 | * Deallocated a rtc allocated with devm_rtc_device_register(). Normally this | |
320 | * function will not need to be called and the resource management code will | |
321 | * ensure that the resource is freed. | |
322 | */ | |
323 | void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc) | |
324 | { | |
325 | int rc; | |
326 | ||
327 | rc = devres_release(dev, devm_rtc_device_release, | |
328 | devm_rtc_device_match, rtc); | |
329 | WARN_ON(rc); | |
330 | } | |
331 | EXPORT_SYMBOL_GPL(devm_rtc_device_unregister); | |
332 | ||
0c86edc0 AZ |
333 | static int __init rtc_init(void) |
334 | { | |
335 | rtc_class = class_create(THIS_MODULE, "rtc"); | |
336 | if (IS_ERR(rtc_class)) { | |
c100a5e0 | 337 | pr_err("couldn't create class\n"); |
0c86edc0 AZ |
338 | return PTR_ERR(rtc_class); |
339 | } | |
92e7f04a | 340 | rtc_class->pm = RTC_CLASS_DEV_PM_OPS; |
5726fb20 | 341 | rtc_dev_init(); |
446ecbd9 | 342 | rtc_sysfs_init(rtc_class); |
0c86edc0 AZ |
343 | return 0; |
344 | } | |
345 | ||
346 | static void __exit rtc_exit(void) | |
347 | { | |
5726fb20 | 348 | rtc_dev_exit(); |
0c86edc0 | 349 | class_destroy(rtc_class); |
6d03d06d | 350 | ida_destroy(&rtc_ida); |
0c86edc0 AZ |
351 | } |
352 | ||
818a8674 | 353 | subsys_initcall(rtc_init); |
0c86edc0 AZ |
354 | module_exit(rtc_exit); |
355 | ||
818a8674 | 356 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); |
0c86edc0 AZ |
357 | MODULE_DESCRIPTION("RTC class support"); |
358 | MODULE_LICENSE("GPL"); |