Commit | Line | Data |
---|---|---|
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 | 16 | #include <linux/module.h> |
9d2b7e53 | 17 | #include <linux/of.h> |
0c86edc0 AZ |
18 | #include <linux/rtc.h> |
19 | #include <linux/kdev_t.h> | |
20 | #include <linux/idr.h> | |
5a0e3ad6 | 21 | #include <linux/slab.h> |
6610e089 | 22 | #include <linux/workqueue.h> |
0c86edc0 | 23 | |
5726fb20 DB |
24 | #include "rtc-core.h" |
25 | ||
26 | ||
6d03d06d | 27 | static DEFINE_IDA(rtc_ida); |
0c86edc0 AZ |
28 | struct class *rtc_class; |
29 | ||
cd966209 | 30 | static void rtc_device_release(struct device *dev) |
0c86edc0 | 31 | { |
cd966209 | 32 | struct rtc_device *rtc = to_rtc_device(dev); |
6d03d06d | 33 | ida_simple_remove(&rtc_ida, rtc->id); |
0c86edc0 AZ |
34 | kfree(rtc); |
35 | } | |
36 | ||
4c24e29e DF |
37 | #ifdef CONFIG_RTC_HCTOSYS_DEVICE |
38 | /* Result of the last RTC to system clock attempt. */ | |
39 | int rtc_hctosys_ret = -ENODEV; | |
40 | #endif | |
7ca1d488 | 41 | |
92e7f04a | 42 | #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE) |
7ca1d488 DB |
43 | /* |
44 | * On suspend(), measure the delta between one RTC and the | |
45 | * system's wall clock; restore it on resume(). | |
46 | */ | |
47 | ||
3dcad5ff JS |
48 | static struct timespec old_rtc, old_system, old_delta; |
49 | ||
7ca1d488 | 50 | |
92e7f04a | 51 | static int rtc_suspend(struct device *dev) |
7ca1d488 DB |
52 | { |
53 | struct rtc_device *rtc = to_rtc_device(dev); | |
54 | struct rtc_time tm; | |
3dcad5ff | 55 | struct timespec delta, delta_delta; |
9ecf37eb FT |
56 | |
57 | if (has_persistent_clock()) | |
58 | return 0; | |
59 | ||
d4afc76c | 60 | if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0) |
7ca1d488 DB |
61 | return 0; |
62 | ||
3dcad5ff | 63 | /* snapshot the current RTC and system time at suspend*/ |
7ca1d488 | 64 | rtc_read_time(rtc, &tm); |
3dcad5ff JS |
65 | getnstimeofday(&old_system); |
66 | rtc_tm_to_time(&tm, &old_rtc.tv_sec); | |
67 | ||
68 | ||
69 | /* | |
70 | * To avoid drift caused by repeated suspend/resumes, | |
71 | * which each can add ~1 second drift error, | |
72 | * try to compensate so the difference in system time | |
73 | * and rtc time stays close to constant. | |
74 | */ | |
75 | delta = timespec_sub(old_system, old_rtc); | |
76 | delta_delta = timespec_sub(delta, old_delta); | |
6a8943d9 | 77 | if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) { |
3dcad5ff JS |
78 | /* |
79 | * if delta_delta is too large, assume time correction | |
80 | * has occured and set old_delta to the current delta. | |
81 | */ | |
82 | old_delta = delta; | |
83 | } else { | |
84 | /* Otherwise try to adjust old_system to compensate */ | |
85 | old_system = timespec_sub(old_system, delta_delta); | |
86 | } | |
7ca1d488 | 87 | |
7ca1d488 DB |
88 | return 0; |
89 | } | |
90 | ||
91 | static int rtc_resume(struct device *dev) | |
92 | { | |
93 | struct rtc_device *rtc = to_rtc_device(dev); | |
94 | struct rtc_time tm; | |
3dcad5ff JS |
95 | struct timespec new_system, new_rtc; |
96 | struct timespec sleep_time; | |
7ca1d488 | 97 | |
9ecf37eb FT |
98 | if (has_persistent_clock()) |
99 | return 0; | |
100 | ||
4c24e29e | 101 | rtc_hctosys_ret = -ENODEV; |
d4afc76c | 102 | if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0) |
7ca1d488 DB |
103 | return 0; |
104 | ||
3dcad5ff JS |
105 | /* snapshot the current rtc and system time at resume */ |
106 | getnstimeofday(&new_system); | |
7ca1d488 DB |
107 | rtc_read_time(rtc, &tm); |
108 | if (rtc_valid_tm(&tm) != 0) { | |
d4afc76c | 109 | pr_debug("%s: bogus resume time\n", dev_name(&rtc->dev)); |
7ca1d488 DB |
110 | return 0; |
111 | } | |
3dcad5ff JS |
112 | rtc_tm_to_time(&tm, &new_rtc.tv_sec); |
113 | new_rtc.tv_nsec = 0; | |
114 | ||
6a8943d9 AH |
115 | if (new_rtc.tv_sec < old_rtc.tv_sec) { |
116 | pr_debug("%s: time travel!\n", dev_name(&rtc->dev)); | |
7ca1d488 DB |
117 | return 0; |
118 | } | |
119 | ||
3dcad5ff JS |
120 | /* calculate the RTC time delta (sleep time)*/ |
121 | sleep_time = timespec_sub(new_rtc, old_rtc); | |
122 | ||
123 | /* | |
124 | * Since these RTC suspend/resume handlers are not called | |
125 | * at the very end of suspend or the start of resume, | |
126 | * some run-time may pass on either sides of the sleep time | |
127 | * so subtract kernel run-time between rtc_suspend to rtc_resume | |
128 | * to keep things accurate. | |
129 | */ | |
130 | sleep_time = timespec_sub(sleep_time, | |
131 | timespec_sub(new_system, old_system)); | |
7ca1d488 | 132 | |
6a8943d9 AH |
133 | if (sleep_time.tv_sec >= 0) |
134 | timekeeping_inject_sleeptime(&sleep_time); | |
4c24e29e | 135 | rtc_hctosys_ret = 0; |
7ca1d488 DB |
136 | return 0; |
137 | } | |
138 | ||
92e7f04a SK |
139 | static SIMPLE_DEV_PM_OPS(rtc_class_dev_pm_ops, rtc_suspend, rtc_resume); |
140 | #define RTC_CLASS_DEV_PM_OPS (&rtc_class_dev_pm_ops) | |
7ca1d488 | 141 | #else |
92e7f04a | 142 | #define RTC_CLASS_DEV_PM_OPS NULL |
7ca1d488 DB |
143 | #endif |
144 | ||
145 | ||
0c86edc0 AZ |
146 | /** |
147 | * rtc_device_register - register w/ RTC class | |
148 | * @dev: the device to register | |
149 | * | |
150 | * rtc_device_unregister() must be called when the class device is no | |
151 | * longer needed. | |
152 | * | |
153 | * Returns the pointer to the new struct class device. | |
154 | */ | |
155 | struct rtc_device *rtc_device_register(const char *name, struct device *dev, | |
ff8371ac | 156 | const struct rtc_class_ops *ops, |
0c86edc0 AZ |
157 | struct module *owner) |
158 | { | |
159 | struct rtc_device *rtc; | |
f44f7f96 | 160 | struct rtc_wkalrm alrm; |
9d2b7e53 SW |
161 | int of_id = -1, id = -1, err; |
162 | ||
163 | if (dev->of_node) | |
164 | of_id = of_alias_get_id(dev->of_node, "rtc"); | |
165 | else if (dev->parent && dev->parent->of_node) | |
166 | of_id = of_alias_get_id(dev->parent->of_node, "rtc"); | |
167 | ||
168 | if (of_id >= 0) { | |
169 | id = ida_simple_get(&rtc_ida, of_id, of_id + 1, | |
170 | GFP_KERNEL); | |
171 | if (id < 0) | |
172 | dev_warn(dev, "/aliases ID %d not available\n", | |
173 | of_id); | |
174 | } | |
0c86edc0 | 175 | |
6d03d06d | 176 | if (id < 0) { |
9d2b7e53 SW |
177 | id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL); |
178 | if (id < 0) { | |
179 | err = id; | |
180 | goto exit; | |
181 | } | |
0c86edc0 AZ |
182 | } |
183 | ||
0c86edc0 AZ |
184 | rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL); |
185 | if (rtc == NULL) { | |
186 | err = -ENOMEM; | |
6d03d06d | 187 | goto exit_ida; |
0c86edc0 AZ |
188 | } |
189 | ||
190 | rtc->id = id; | |
191 | rtc->ops = ops; | |
192 | rtc->owner = owner; | |
83a06bf5 | 193 | rtc->irq_freq = 1; |
110d693d | 194 | rtc->max_user_freq = 64; |
cd966209 DB |
195 | rtc->dev.parent = dev; |
196 | rtc->dev.class = rtc_class; | |
197 | rtc->dev.release = rtc_device_release; | |
0c86edc0 AZ |
198 | |
199 | mutex_init(&rtc->ops_lock); | |
200 | spin_lock_init(&rtc->irq_lock); | |
201 | spin_lock_init(&rtc->irq_task_lock); | |
d691eb90 | 202 | init_waitqueue_head(&rtc->irq_queue); |
0c86edc0 | 203 | |
6610e089 JS |
204 | /* Init timerqueue */ |
205 | timerqueue_init_head(&rtc->timerqueue); | |
96c8f06a | 206 | INIT_WORK(&rtc->irqwork, rtc_timer_do_work); |
6610e089 | 207 | /* Init aie timer */ |
96c8f06a | 208 | rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc); |
6610e089 | 209 | /* Init uie timer */ |
96c8f06a | 210 | rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc); |
6610e089 JS |
211 | /* Init pie timer */ |
212 | hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
213 | rtc->pie_timer.function = rtc_pie_update_irq; | |
214 | rtc->pie_enabled = 0; | |
215 | ||
f44f7f96 JS |
216 | /* Check to see if there is an ALARM already set in hw */ |
217 | err = __rtc_read_alarm(rtc, &alrm); | |
218 | ||
219 | if (!err && !rtc_valid_tm(&alrm.time)) | |
f6d5b331 | 220 | rtc_initialize_alarm(rtc, &alrm); |
f44f7f96 | 221 | |
0c86edc0 | 222 | strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE); |
d4afc76c | 223 | dev_set_name(&rtc->dev, "rtc%d", id); |
0c86edc0 | 224 | |
cb3a58d2 DB |
225 | rtc_dev_prepare(rtc); |
226 | ||
cd966209 | 227 | err = device_register(&rtc->dev); |
59cca865 VK |
228 | if (err) { |
229 | put_device(&rtc->dev); | |
0c86edc0 | 230 | goto exit_kfree; |
59cca865 | 231 | } |
0c86edc0 | 232 | |
5726fb20 | 233 | rtc_dev_add_device(rtc); |
446ecbd9 | 234 | rtc_sysfs_add_device(rtc); |
7d9f99ec | 235 | rtc_proc_add_device(rtc); |
5726fb20 | 236 | |
0c86edc0 | 237 | dev_info(dev, "rtc core: registered %s as %s\n", |
d4afc76c | 238 | rtc->name, dev_name(&rtc->dev)); |
0c86edc0 AZ |
239 | |
240 | return rtc; | |
241 | ||
242 | exit_kfree: | |
243 | kfree(rtc); | |
244 | ||
6d03d06d JC |
245 | exit_ida: |
246 | ida_simple_remove(&rtc_ida, id); | |
0c86edc0 AZ |
247 | |
248 | exit: | |
d1d65b77 AZ |
249 | dev_err(dev, "rtc core: unable to register %s, err = %d\n", |
250 | name, err); | |
0c86edc0 AZ |
251 | return ERR_PTR(err); |
252 | } | |
253 | EXPORT_SYMBOL_GPL(rtc_device_register); | |
254 | ||
255 | ||
256 | /** | |
257 | * rtc_device_unregister - removes the previously registered RTC class device | |
258 | * | |
259 | * @rtc: the RTC class device to destroy | |
260 | */ | |
261 | void rtc_device_unregister(struct rtc_device *rtc) | |
262 | { | |
cd966209 | 263 | if (get_device(&rtc->dev) != NULL) { |
e109ebd1 DB |
264 | mutex_lock(&rtc->ops_lock); |
265 | /* remove innards of this RTC, then disable it, before | |
266 | * letting any rtc_class_open() users access it again | |
267 | */ | |
446ecbd9 | 268 | rtc_sysfs_del_device(rtc); |
5726fb20 | 269 | rtc_dev_del_device(rtc); |
7d9f99ec | 270 | rtc_proc_del_device(rtc); |
cd966209 | 271 | device_unregister(&rtc->dev); |
e109ebd1 DB |
272 | rtc->ops = NULL; |
273 | mutex_unlock(&rtc->ops_lock); | |
cd966209 | 274 | put_device(&rtc->dev); |
e109ebd1 | 275 | } |
0c86edc0 AZ |
276 | } |
277 | EXPORT_SYMBOL_GPL(rtc_device_unregister); | |
278 | ||
3e217b66 JH |
279 | static void devm_rtc_device_release(struct device *dev, void *res) |
280 | { | |
281 | struct rtc_device *rtc = *(struct rtc_device **)res; | |
282 | ||
283 | rtc_device_unregister(rtc); | |
284 | } | |
285 | ||
286 | static int devm_rtc_device_match(struct device *dev, void *res, void *data) | |
287 | { | |
288 | struct rtc **r = res; | |
289 | ||
290 | return *r == data; | |
291 | } | |
292 | ||
293 | /** | |
294 | * devm_rtc_device_register - resource managed rtc_device_register() | |
3e217b66 | 295 | * @dev: the device to register |
6636a994 | 296 | * @name: the name of the device |
3e217b66 JH |
297 | * @ops: the rtc operations structure |
298 | * @owner: the module owner | |
299 | * | |
300 | * @return a struct rtc on success, or an ERR_PTR on error | |
301 | * | |
302 | * Managed rtc_device_register(). The rtc_device returned from this function | |
303 | * are automatically freed on driver detach. See rtc_device_register() | |
304 | * for more information. | |
305 | */ | |
306 | ||
6636a994 JH |
307 | struct rtc_device *devm_rtc_device_register(struct device *dev, |
308 | const char *name, | |
3e217b66 JH |
309 | const struct rtc_class_ops *ops, |
310 | struct module *owner) | |
311 | { | |
312 | struct rtc_device **ptr, *rtc; | |
313 | ||
314 | ptr = devres_alloc(devm_rtc_device_release, sizeof(*ptr), GFP_KERNEL); | |
315 | if (!ptr) | |
316 | return ERR_PTR(-ENOMEM); | |
317 | ||
318 | rtc = rtc_device_register(name, dev, ops, owner); | |
319 | if (!IS_ERR(rtc)) { | |
320 | *ptr = rtc; | |
321 | devres_add(dev, ptr); | |
322 | } else { | |
323 | devres_free(ptr); | |
324 | } | |
325 | ||
326 | return rtc; | |
327 | } | |
328 | EXPORT_SYMBOL_GPL(devm_rtc_device_register); | |
329 | ||
330 | /** | |
331 | * devm_rtc_device_unregister - resource managed devm_rtc_device_unregister() | |
332 | * @dev: the device to unregister | |
333 | * @rtc: the RTC class device to unregister | |
334 | * | |
335 | * Deallocated a rtc allocated with devm_rtc_device_register(). Normally this | |
336 | * function will not need to be called and the resource management code will | |
337 | * ensure that the resource is freed. | |
338 | */ | |
339 | void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc) | |
340 | { | |
341 | int rc; | |
342 | ||
343 | rc = devres_release(dev, devm_rtc_device_release, | |
344 | devm_rtc_device_match, rtc); | |
345 | WARN_ON(rc); | |
346 | } | |
347 | EXPORT_SYMBOL_GPL(devm_rtc_device_unregister); | |
348 | ||
0c86edc0 AZ |
349 | static int __init rtc_init(void) |
350 | { | |
351 | rtc_class = class_create(THIS_MODULE, "rtc"); | |
352 | if (IS_ERR(rtc_class)) { | |
c100a5e0 | 353 | pr_err("couldn't create class\n"); |
0c86edc0 AZ |
354 | return PTR_ERR(rtc_class); |
355 | } | |
92e7f04a | 356 | rtc_class->pm = RTC_CLASS_DEV_PM_OPS; |
5726fb20 | 357 | rtc_dev_init(); |
446ecbd9 | 358 | rtc_sysfs_init(rtc_class); |
0c86edc0 AZ |
359 | return 0; |
360 | } | |
361 | ||
362 | static void __exit rtc_exit(void) | |
363 | { | |
5726fb20 | 364 | rtc_dev_exit(); |
0c86edc0 | 365 | class_destroy(rtc_class); |
6d03d06d | 366 | ida_destroy(&rtc_ida); |
0c86edc0 AZ |
367 | } |
368 | ||
818a8674 | 369 | subsys_initcall(rtc_init); |
0c86edc0 AZ |
370 | module_exit(rtc_exit); |
371 | ||
818a8674 | 372 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); |
0c86edc0 AZ |
373 | MODULE_DESCRIPTION("RTC class support"); |
374 | MODULE_LICENSE("GPL"); |