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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 | 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 | ||
d4bda8f8 | 48 | static struct timespec64 old_rtc, old_system, old_delta; |
3dcad5ff | 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; | |
d4bda8f8 | 55 | struct timespec64 delta, delta_delta; |
e1d60093 | 56 | int err; |
9ecf37eb | 57 | |
0fa88cb4 | 58 | if (timekeeping_rtc_skipsuspend()) |
9ecf37eb FT |
59 | return 0; |
60 | ||
d4afc76c | 61 | if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0) |
7ca1d488 DB |
62 | return 0; |
63 | ||
3dcad5ff | 64 | /* snapshot the current RTC and system time at suspend*/ |
e1d60093 HG |
65 | err = rtc_read_time(rtc, &tm); |
66 | if (err < 0) { | |
67 | pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev)); | |
68 | return 0; | |
69 | } | |
70 | ||
d4bda8f8 JS |
71 | getnstimeofday64(&old_system); |
72 | old_rtc.tv_sec = rtc_tm_to_time64(&tm); | |
3dcad5ff JS |
73 | |
74 | ||
75 | /* | |
76 | * To avoid drift caused by repeated suspend/resumes, | |
77 | * which each can add ~1 second drift error, | |
78 | * try to compensate so the difference in system time | |
79 | * and rtc time stays close to constant. | |
80 | */ | |
d4bda8f8 JS |
81 | delta = timespec64_sub(old_system, old_rtc); |
82 | delta_delta = timespec64_sub(delta, old_delta); | |
6a8943d9 | 83 | if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) { |
3dcad5ff JS |
84 | /* |
85 | * if delta_delta is too large, assume time correction | |
86 | * has occured and set old_delta to the current delta. | |
87 | */ | |
88 | old_delta = delta; | |
89 | } else { | |
90 | /* Otherwise try to adjust old_system to compensate */ | |
d4bda8f8 | 91 | old_system = timespec64_sub(old_system, delta_delta); |
3dcad5ff | 92 | } |
7ca1d488 | 93 | |
7ca1d488 DB |
94 | return 0; |
95 | } | |
96 | ||
97 | static int rtc_resume(struct device *dev) | |
98 | { | |
99 | struct rtc_device *rtc = to_rtc_device(dev); | |
100 | struct rtc_time tm; | |
d4bda8f8 JS |
101 | struct timespec64 new_system, new_rtc; |
102 | struct timespec64 sleep_time; | |
e1d60093 | 103 | int err; |
7ca1d488 | 104 | |
0fa88cb4 | 105 | if (timekeeping_rtc_skipresume()) |
9ecf37eb FT |
106 | return 0; |
107 | ||
4c24e29e | 108 | rtc_hctosys_ret = -ENODEV; |
d4afc76c | 109 | if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0) |
7ca1d488 DB |
110 | return 0; |
111 | ||
3dcad5ff | 112 | /* snapshot the current rtc and system time at resume */ |
d4bda8f8 | 113 | getnstimeofday64(&new_system); |
e1d60093 HG |
114 | err = rtc_read_time(rtc, &tm); |
115 | if (err < 0) { | |
116 | pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev)); | |
117 | return 0; | |
118 | } | |
119 | ||
d4bda8f8 | 120 | new_rtc.tv_sec = rtc_tm_to_time64(&tm); |
3dcad5ff JS |
121 | new_rtc.tv_nsec = 0; |
122 | ||
6a8943d9 AH |
123 | if (new_rtc.tv_sec < old_rtc.tv_sec) { |
124 | pr_debug("%s: time travel!\n", dev_name(&rtc->dev)); | |
7ca1d488 DB |
125 | return 0; |
126 | } | |
127 | ||
3dcad5ff | 128 | /* calculate the RTC time delta (sleep time)*/ |
d4bda8f8 | 129 | sleep_time = timespec64_sub(new_rtc, old_rtc); |
3dcad5ff JS |
130 | |
131 | /* | |
132 | * Since these RTC suspend/resume handlers are not called | |
133 | * at the very end of suspend or the start of resume, | |
134 | * some run-time may pass on either sides of the sleep time | |
135 | * so subtract kernel run-time between rtc_suspend to rtc_resume | |
136 | * to keep things accurate. | |
137 | */ | |
d4bda8f8 JS |
138 | sleep_time = timespec64_sub(sleep_time, |
139 | timespec64_sub(new_system, old_system)); | |
7ca1d488 | 140 | |
6a8943d9 | 141 | if (sleep_time.tv_sec >= 0) |
d4bda8f8 | 142 | timekeeping_inject_sleeptime64(&sleep_time); |
4c24e29e | 143 | rtc_hctosys_ret = 0; |
7ca1d488 DB |
144 | return 0; |
145 | } | |
146 | ||
92e7f04a SK |
147 | static SIMPLE_DEV_PM_OPS(rtc_class_dev_pm_ops, rtc_suspend, rtc_resume); |
148 | #define RTC_CLASS_DEV_PM_OPS (&rtc_class_dev_pm_ops) | |
7ca1d488 | 149 | #else |
92e7f04a | 150 | #define RTC_CLASS_DEV_PM_OPS NULL |
7ca1d488 DB |
151 | #endif |
152 | ||
3068a254 | 153 | /* Ensure the caller will set the id before releasing the device */ |
d1bec20f AB |
154 | static struct rtc_device *rtc_allocate_device(void) |
155 | { | |
156 | struct rtc_device *rtc; | |
157 | ||
158 | rtc = kzalloc(sizeof(*rtc), GFP_KERNEL); | |
159 | if (!rtc) | |
160 | return NULL; | |
161 | ||
162 | device_initialize(&rtc->dev); | |
163 | ||
164 | rtc->irq_freq = 1; | |
165 | rtc->max_user_freq = 64; | |
166 | rtc->dev.class = rtc_class; | |
167 | rtc->dev.groups = rtc_get_dev_attribute_groups(); | |
168 | rtc->dev.release = rtc_device_release; | |
169 | ||
170 | mutex_init(&rtc->ops_lock); | |
171 | spin_lock_init(&rtc->irq_lock); | |
172 | spin_lock_init(&rtc->irq_task_lock); | |
173 | init_waitqueue_head(&rtc->irq_queue); | |
174 | ||
175 | /* Init timerqueue */ | |
176 | timerqueue_init_head(&rtc->timerqueue); | |
177 | INIT_WORK(&rtc->irqwork, rtc_timer_do_work); | |
178 | /* Init aie timer */ | |
179 | rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc); | |
180 | /* Init uie timer */ | |
181 | rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc); | |
182 | /* Init pie timer */ | |
183 | hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
184 | rtc->pie_timer.function = rtc_pie_update_irq; | |
185 | rtc->pie_enabled = 0; | |
186 | ||
187 | return rtc; | |
188 | } | |
7ca1d488 | 189 | |
b91336df AB |
190 | static int rtc_device_get_id(struct device *dev) |
191 | { | |
192 | int of_id = -1, id = -1; | |
193 | ||
194 | if (dev->of_node) | |
195 | of_id = of_alias_get_id(dev->of_node, "rtc"); | |
196 | else if (dev->parent && dev->parent->of_node) | |
197 | of_id = of_alias_get_id(dev->parent->of_node, "rtc"); | |
198 | ||
199 | if (of_id >= 0) { | |
200 | id = ida_simple_get(&rtc_ida, of_id, of_id + 1, GFP_KERNEL); | |
201 | if (id < 0) | |
202 | dev_warn(dev, "/aliases ID %d not available\n", of_id); | |
203 | } | |
204 | ||
205 | if (id < 0) | |
206 | id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL); | |
207 | ||
208 | return id; | |
209 | } | |
210 | ||
0c86edc0 AZ |
211 | /** |
212 | * rtc_device_register - register w/ RTC class | |
213 | * @dev: the device to register | |
214 | * | |
215 | * rtc_device_unregister() must be called when the class device is no | |
216 | * longer needed. | |
217 | * | |
218 | * Returns the pointer to the new struct class device. | |
219 | */ | |
220 | struct rtc_device *rtc_device_register(const char *name, struct device *dev, | |
ff8371ac | 221 | const struct rtc_class_ops *ops, |
0c86edc0 AZ |
222 | struct module *owner) |
223 | { | |
224 | struct rtc_device *rtc; | |
f44f7f96 | 225 | struct rtc_wkalrm alrm; |
b91336df | 226 | int id, err; |
0c86edc0 | 227 | |
b91336df | 228 | id = rtc_device_get_id(dev); |
6d03d06d | 229 | if (id < 0) { |
b91336df AB |
230 | err = id; |
231 | goto exit; | |
0c86edc0 AZ |
232 | } |
233 | ||
d1bec20f AB |
234 | rtc = rtc_allocate_device(); |
235 | if (!rtc) { | |
0c86edc0 | 236 | err = -ENOMEM; |
6d03d06d | 237 | goto exit_ida; |
0c86edc0 AZ |
238 | } |
239 | ||
240 | rtc->id = id; | |
241 | rtc->ops = ops; | |
242 | rtc->owner = owner; | |
cd966209 | 243 | rtc->dev.parent = dev; |
6610e089 | 244 | |
182683e9 AK |
245 | dev_set_name(&rtc->dev, "rtc%d", id); |
246 | ||
f44f7f96 JS |
247 | /* Check to see if there is an ALARM already set in hw */ |
248 | err = __rtc_read_alarm(rtc, &alrm); | |
249 | ||
250 | if (!err && !rtc_valid_tm(&alrm.time)) | |
f6d5b331 | 251 | rtc_initialize_alarm(rtc, &alrm); |
f44f7f96 | 252 | |
cb3a58d2 DB |
253 | rtc_dev_prepare(rtc); |
254 | ||
d5ed9177 | 255 | err = cdev_device_add(&rtc->char_dev, &rtc->dev); |
59cca865 | 256 | if (err) { |
d5ed9177 | 257 | dev_warn(&rtc->dev, "%s: failed to add char device %d:%d\n", |
5c82a6ae | 258 | name, MAJOR(rtc->dev.devt), rtc->id); |
d5ed9177 | 259 | |
6706664d | 260 | /* This will free both memory and the ID */ |
59cca865 | 261 | put_device(&rtc->dev); |
6706664d | 262 | goto exit; |
d5ed9177 | 263 | } else { |
5c82a6ae | 264 | dev_dbg(&rtc->dev, "%s: dev (%d:%d)\n", name, |
d5ed9177 | 265 | MAJOR(rtc->dev.devt), rtc->id); |
59cca865 | 266 | } |
0c86edc0 | 267 | |
7d9f99ec | 268 | rtc_proc_add_device(rtc); |
5726fb20 | 269 | |
0c86edc0 | 270 | dev_info(dev, "rtc core: registered %s as %s\n", |
5c82a6ae | 271 | name, dev_name(&rtc->dev)); |
0c86edc0 AZ |
272 | |
273 | return rtc; | |
274 | ||
6d03d06d JC |
275 | exit_ida: |
276 | ida_simple_remove(&rtc_ida, id); | |
0c86edc0 AZ |
277 | |
278 | exit: | |
d1d65b77 AZ |
279 | dev_err(dev, "rtc core: unable to register %s, err = %d\n", |
280 | name, err); | |
0c86edc0 AZ |
281 | return ERR_PTR(err); |
282 | } | |
283 | EXPORT_SYMBOL_GPL(rtc_device_register); | |
284 | ||
285 | ||
286 | /** | |
287 | * rtc_device_unregister - removes the previously registered RTC class device | |
288 | * | |
289 | * @rtc: the RTC class device to destroy | |
290 | */ | |
291 | void rtc_device_unregister(struct rtc_device *rtc) | |
292 | { | |
697e5a47 AB |
293 | rtc_nvmem_unregister(rtc); |
294 | ||
c3b399a4 DT |
295 | mutex_lock(&rtc->ops_lock); |
296 | /* | |
297 | * Remove innards of this RTC, then disable it, before | |
298 | * letting any rtc_class_open() users access it again | |
299 | */ | |
c3b399a4 | 300 | rtc_proc_del_device(rtc); |
d5ed9177 | 301 | cdev_device_del(&rtc->char_dev, &rtc->dev); |
c3b399a4 DT |
302 | rtc->ops = NULL; |
303 | mutex_unlock(&rtc->ops_lock); | |
304 | put_device(&rtc->dev); | |
0c86edc0 AZ |
305 | } |
306 | EXPORT_SYMBOL_GPL(rtc_device_unregister); | |
307 | ||
3e217b66 JH |
308 | static void devm_rtc_device_release(struct device *dev, void *res) |
309 | { | |
310 | struct rtc_device *rtc = *(struct rtc_device **)res; | |
311 | ||
312 | rtc_device_unregister(rtc); | |
313 | } | |
314 | ||
315 | static int devm_rtc_device_match(struct device *dev, void *res, void *data) | |
316 | { | |
317 | struct rtc **r = res; | |
318 | ||
319 | return *r == data; | |
320 | } | |
321 | ||
322 | /** | |
323 | * devm_rtc_device_register - resource managed rtc_device_register() | |
3e217b66 | 324 | * @dev: the device to register |
6636a994 | 325 | * @name: the name of the device |
3e217b66 JH |
326 | * @ops: the rtc operations structure |
327 | * @owner: the module owner | |
328 | * | |
329 | * @return a struct rtc on success, or an ERR_PTR on error | |
330 | * | |
331 | * Managed rtc_device_register(). The rtc_device returned from this function | |
332 | * are automatically freed on driver detach. See rtc_device_register() | |
333 | * for more information. | |
334 | */ | |
335 | ||
6636a994 JH |
336 | struct rtc_device *devm_rtc_device_register(struct device *dev, |
337 | const char *name, | |
3e217b66 JH |
338 | const struct rtc_class_ops *ops, |
339 | struct module *owner) | |
340 | { | |
341 | struct rtc_device **ptr, *rtc; | |
342 | ||
343 | ptr = devres_alloc(devm_rtc_device_release, sizeof(*ptr), GFP_KERNEL); | |
344 | if (!ptr) | |
345 | return ERR_PTR(-ENOMEM); | |
346 | ||
347 | rtc = rtc_device_register(name, dev, ops, owner); | |
348 | if (!IS_ERR(rtc)) { | |
349 | *ptr = rtc; | |
350 | devres_add(dev, ptr); | |
351 | } else { | |
352 | devres_free(ptr); | |
353 | } | |
354 | ||
355 | return rtc; | |
356 | } | |
357 | EXPORT_SYMBOL_GPL(devm_rtc_device_register); | |
358 | ||
359 | /** | |
360 | * devm_rtc_device_unregister - resource managed devm_rtc_device_unregister() | |
361 | * @dev: the device to unregister | |
362 | * @rtc: the RTC class device to unregister | |
363 | * | |
364 | * Deallocated a rtc allocated with devm_rtc_device_register(). Normally this | |
365 | * function will not need to be called and the resource management code will | |
366 | * ensure that the resource is freed. | |
367 | */ | |
368 | void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc) | |
369 | { | |
370 | int rc; | |
371 | ||
372 | rc = devres_release(dev, devm_rtc_device_release, | |
373 | devm_rtc_device_match, rtc); | |
374 | WARN_ON(rc); | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(devm_rtc_device_unregister); | |
377 | ||
3068a254 AB |
378 | static void devm_rtc_release_device(struct device *dev, void *res) |
379 | { | |
380 | struct rtc_device *rtc = *(struct rtc_device **)res; | |
381 | ||
382 | if (rtc->registered) | |
383 | rtc_device_unregister(rtc); | |
384 | else | |
385 | put_device(&rtc->dev); | |
386 | } | |
387 | ||
388 | struct rtc_device *devm_rtc_allocate_device(struct device *dev) | |
389 | { | |
390 | struct rtc_device **ptr, *rtc; | |
391 | int id, err; | |
392 | ||
393 | id = rtc_device_get_id(dev); | |
394 | if (id < 0) | |
395 | return ERR_PTR(id); | |
396 | ||
397 | ptr = devres_alloc(devm_rtc_release_device, sizeof(*ptr), GFP_KERNEL); | |
398 | if (!ptr) { | |
399 | err = -ENOMEM; | |
400 | goto exit_ida; | |
401 | } | |
402 | ||
403 | rtc = rtc_allocate_device(); | |
404 | if (!rtc) { | |
405 | err = -ENOMEM; | |
406 | goto exit_devres; | |
407 | } | |
408 | ||
409 | *ptr = rtc; | |
410 | devres_add(dev, ptr); | |
411 | ||
412 | rtc->id = id; | |
413 | rtc->dev.parent = dev; | |
414 | dev_set_name(&rtc->dev, "rtc%d", id); | |
415 | ||
416 | return rtc; | |
417 | ||
418 | exit_devres: | |
419 | devres_free(ptr); | |
420 | exit_ida: | |
421 | ida_simple_remove(&rtc_ida, id); | |
422 | return ERR_PTR(err); | |
423 | } | |
424 | EXPORT_SYMBOL_GPL(devm_rtc_allocate_device); | |
425 | ||
426 | int __rtc_register_device(struct module *owner, struct rtc_device *rtc) | |
427 | { | |
428 | struct rtc_wkalrm alrm; | |
429 | int err; | |
430 | ||
431 | if (!rtc->ops) | |
432 | return -EINVAL; | |
433 | ||
434 | rtc->owner = owner; | |
435 | ||
436 | /* Check to see if there is an ALARM already set in hw */ | |
437 | err = __rtc_read_alarm(rtc, &alrm); | |
438 | if (!err && !rtc_valid_tm(&alrm.time)) | |
439 | rtc_initialize_alarm(rtc, &alrm); | |
440 | ||
441 | rtc_dev_prepare(rtc); | |
442 | ||
443 | err = cdev_device_add(&rtc->char_dev, &rtc->dev); | |
444 | if (err) | |
445 | dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n", | |
446 | MAJOR(rtc->dev.devt), rtc->id); | |
447 | else | |
448 | dev_dbg(rtc->dev.parent, "char device (%d:%d)\n", | |
449 | MAJOR(rtc->dev.devt), rtc->id); | |
450 | ||
451 | rtc_proc_add_device(rtc); | |
452 | ||
697e5a47 AB |
453 | rtc_nvmem_register(rtc); |
454 | ||
3068a254 AB |
455 | rtc->registered = true; |
456 | dev_info(rtc->dev.parent, "registered as %s\n", | |
457 | dev_name(&rtc->dev)); | |
458 | ||
459 | return 0; | |
460 | } | |
461 | EXPORT_SYMBOL_GPL(__rtc_register_device); | |
462 | ||
0c86edc0 AZ |
463 | static int __init rtc_init(void) |
464 | { | |
465 | rtc_class = class_create(THIS_MODULE, "rtc"); | |
466 | if (IS_ERR(rtc_class)) { | |
c100a5e0 | 467 | pr_err("couldn't create class\n"); |
0c86edc0 AZ |
468 | return PTR_ERR(rtc_class); |
469 | } | |
92e7f04a | 470 | rtc_class->pm = RTC_CLASS_DEV_PM_OPS; |
5726fb20 | 471 | rtc_dev_init(); |
0c86edc0 AZ |
472 | return 0; |
473 | } | |
818a8674 | 474 | subsys_initcall(rtc_init); |