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11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/rtc.h>
16#include <linux/kdev_t.h>
17#include <linux/idr.h>
18#include <linux/slab.h>
19#include <linux/workqueue.h>
20
21#include "rtc-core.h"
22
23static DEFINE_IDA(rtc_ida);
24struct class *rtc_class;
25
26static void rtc_device_release(struct device *dev)
27{
28 struct rtc_device *rtc = to_rtc_device(dev);
29
30 ida_simple_remove(&rtc_ida, rtc->id);
31 mutex_destroy(&rtc->ops_lock);
32 kfree(rtc);
33}
34
35#ifdef CONFIG_RTC_HCTOSYS_DEVICE
36
37int rtc_hctosys_ret = -ENODEV;
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50static void rtc_hctosys(struct rtc_device *rtc)
51{
52 int err;
53 struct rtc_time tm;
54 struct timespec64 tv64 = {
55 .tv_nsec = NSEC_PER_SEC >> 1,
56 };
57
58 err = rtc_read_time(rtc, &tm);
59 if (err) {
60 dev_err(rtc->dev.parent,
61 "hctosys: unable to read the hardware clock\n");
62 goto err_read;
63 }
64
65 tv64.tv_sec = rtc_tm_to_time64(&tm);
66
67#if BITS_PER_LONG == 32
68 if (tv64.tv_sec > INT_MAX) {
69 err = -ERANGE;
70 goto err_read;
71 }
72#endif
73
74 err = do_settimeofday64(&tv64);
75
76 dev_info(rtc->dev.parent, "setting system clock to %ptR UTC (%lld)\n",
77 &tm, (long long)tv64.tv_sec);
78
79err_read:
80 rtc_hctosys_ret = err;
81}
82#endif
83
84#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE)
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89
90static struct timespec64 old_rtc, old_system, old_delta;
91
92static int rtc_suspend(struct device *dev)
93{
94 struct rtc_device *rtc = to_rtc_device(dev);
95 struct rtc_time tm;
96 struct timespec64 delta, delta_delta;
97 int err;
98
99 if (timekeeping_rtc_skipsuspend())
100 return 0;
101
102 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
103 return 0;
104
105
106 err = rtc_read_time(rtc, &tm);
107 if (err < 0) {
108 pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev));
109 return 0;
110 }
111
112 ktime_get_real_ts64(&old_system);
113 old_rtc.tv_sec = rtc_tm_to_time64(&tm);
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121 delta = timespec64_sub(old_system, old_rtc);
122 delta_delta = timespec64_sub(delta, old_delta);
123 if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) {
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128 old_delta = delta;
129 } else {
130
131 old_system = timespec64_sub(old_system, delta_delta);
132 }
133
134 return 0;
135}
136
137static int rtc_resume(struct device *dev)
138{
139 struct rtc_device *rtc = to_rtc_device(dev);
140 struct rtc_time tm;
141 struct timespec64 new_system, new_rtc;
142 struct timespec64 sleep_time;
143 int err;
144
145 if (timekeeping_rtc_skipresume())
146 return 0;
147
148 rtc_hctosys_ret = -ENODEV;
149 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
150 return 0;
151
152
153 ktime_get_real_ts64(&new_system);
154 err = rtc_read_time(rtc, &tm);
155 if (err < 0) {
156 pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev));
157 return 0;
158 }
159
160 new_rtc.tv_sec = rtc_tm_to_time64(&tm);
161 new_rtc.tv_nsec = 0;
162
163 if (new_rtc.tv_sec < old_rtc.tv_sec) {
164 pr_debug("%s: time travel!\n", dev_name(&rtc->dev));
165 return 0;
166 }
167
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169 sleep_time = timespec64_sub(new_rtc, old_rtc);
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178 sleep_time = timespec64_sub(sleep_time,
179 timespec64_sub(new_system, old_system));
180
181 if (sleep_time.tv_sec >= 0)
182 timekeeping_inject_sleeptime64(&sleep_time);
183 rtc_hctosys_ret = 0;
184 return 0;
185}
186
187static SIMPLE_DEV_PM_OPS(rtc_class_dev_pm_ops, rtc_suspend, rtc_resume);
188#define RTC_CLASS_DEV_PM_OPS (&rtc_class_dev_pm_ops)
189#else
190#define RTC_CLASS_DEV_PM_OPS NULL
191#endif
192
193
194static struct rtc_device *rtc_allocate_device(void)
195{
196 struct rtc_device *rtc;
197
198 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
199 if (!rtc)
200 return NULL;
201
202 device_initialize(&rtc->dev);
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210 rtc->set_offset_nsec = NSEC_PER_SEC + 5 * NSEC_PER_MSEC;
211
212 rtc->irq_freq = 1;
213 rtc->max_user_freq = 64;
214 rtc->dev.class = rtc_class;
215 rtc->dev.groups = rtc_get_dev_attribute_groups();
216 rtc->dev.release = rtc_device_release;
217
218 mutex_init(&rtc->ops_lock);
219 spin_lock_init(&rtc->irq_lock);
220 init_waitqueue_head(&rtc->irq_queue);
221
222
223 timerqueue_init_head(&rtc->timerqueue);
224 INIT_WORK(&rtc->irqwork, rtc_timer_do_work);
225
226 rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, rtc);
227
228 rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, rtc);
229
230 hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
231 rtc->pie_timer.function = rtc_pie_update_irq;
232 rtc->pie_enabled = 0;
233
234 set_bit(RTC_FEATURE_ALARM, rtc->features);
235
236 return rtc;
237}
238
239static int rtc_device_get_id(struct device *dev)
240{
241 int of_id = -1, id = -1;
242
243 if (dev->of_node)
244 of_id = of_alias_get_id(dev->of_node, "rtc");
245 else if (dev->parent && dev->parent->of_node)
246 of_id = of_alias_get_id(dev->parent->of_node, "rtc");
247
248 if (of_id >= 0) {
249 id = ida_simple_get(&rtc_ida, of_id, of_id + 1, GFP_KERNEL);
250 if (id < 0)
251 dev_warn(dev, "/aliases ID %d not available\n", of_id);
252 }
253
254 if (id < 0)
255 id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL);
256
257 return id;
258}
259
260static void rtc_device_get_offset(struct rtc_device *rtc)
261{
262 time64_t range_secs;
263 u32 start_year;
264 int ret;
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271 if (rtc->range_min == rtc->range_max)
272 return;
273
274 ret = device_property_read_u32(rtc->dev.parent, "start-year",
275 &start_year);
276 if (!ret) {
277 rtc->start_secs = mktime64(start_year, 1, 1, 0, 0, 0);
278 rtc->set_start_time = true;
279 }
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285 if (!rtc->set_start_time)
286 return;
287
288 range_secs = rtc->range_max - rtc->range_min + 1;
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316 if (rtc->start_secs > rtc->range_max ||
317 rtc->start_secs + range_secs - 1 < rtc->range_min)
318 rtc->offset_secs = rtc->start_secs - rtc->range_min;
319 else if (rtc->start_secs > rtc->range_min)
320 rtc->offset_secs = range_secs;
321 else if (rtc->start_secs < rtc->range_min)
322 rtc->offset_secs = -range_secs;
323 else
324 rtc->offset_secs = 0;
325}
326
327static void devm_rtc_unregister_device(void *data)
328{
329 struct rtc_device *rtc = data;
330
331 mutex_lock(&rtc->ops_lock);
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336 rtc_proc_del_device(rtc);
337 cdev_device_del(&rtc->char_dev, &rtc->dev);
338 rtc->ops = NULL;
339 mutex_unlock(&rtc->ops_lock);
340}
341
342static void devm_rtc_release_device(void *res)
343{
344 struct rtc_device *rtc = res;
345
346 put_device(&rtc->dev);
347}
348
349struct rtc_device *devm_rtc_allocate_device(struct device *dev)
350{
351 struct rtc_device *rtc;
352 int id, err;
353
354 id = rtc_device_get_id(dev);
355 if (id < 0)
356 return ERR_PTR(id);
357
358 rtc = rtc_allocate_device();
359 if (!rtc) {
360 ida_simple_remove(&rtc_ida, id);
361 return ERR_PTR(-ENOMEM);
362 }
363
364 rtc->id = id;
365 rtc->dev.parent = dev;
366 dev_set_name(&rtc->dev, "rtc%d", id);
367
368 err = devm_add_action_or_reset(dev, devm_rtc_release_device, rtc);
369 if (err)
370 return ERR_PTR(err);
371
372 return rtc;
373}
374EXPORT_SYMBOL_GPL(devm_rtc_allocate_device);
375
376int __devm_rtc_register_device(struct module *owner, struct rtc_device *rtc)
377{
378 struct rtc_wkalrm alrm;
379 int err;
380
381 if (!rtc->ops) {
382 dev_dbg(&rtc->dev, "no ops set\n");
383 return -EINVAL;
384 }
385
386 if (!rtc->ops->set_alarm)
387 clear_bit(RTC_FEATURE_ALARM, rtc->features);
388
389 rtc->owner = owner;
390 rtc_device_get_offset(rtc);
391
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393 err = __rtc_read_alarm(rtc, &alrm);
394 if (!err && !rtc_valid_tm(&alrm.time))
395 rtc_initialize_alarm(rtc, &alrm);
396
397 rtc_dev_prepare(rtc);
398
399 err = cdev_device_add(&rtc->char_dev, &rtc->dev);
400 if (err)
401 dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n",
402 MAJOR(rtc->dev.devt), rtc->id);
403 else
404 dev_dbg(rtc->dev.parent, "char device (%d:%d)\n",
405 MAJOR(rtc->dev.devt), rtc->id);
406
407 rtc_proc_add_device(rtc);
408
409 dev_info(rtc->dev.parent, "registered as %s\n",
410 dev_name(&rtc->dev));
411
412#ifdef CONFIG_RTC_HCTOSYS_DEVICE
413 if (!strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE))
414 rtc_hctosys(rtc);
415#endif
416
417 return devm_add_action_or_reset(rtc->dev.parent,
418 devm_rtc_unregister_device, rtc);
419}
420EXPORT_SYMBOL_GPL(__devm_rtc_register_device);
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436struct rtc_device *devm_rtc_device_register(struct device *dev,
437 const char *name,
438 const struct rtc_class_ops *ops,
439 struct module *owner)
440{
441 struct rtc_device *rtc;
442 int err;
443
444 rtc = devm_rtc_allocate_device(dev);
445 if (IS_ERR(rtc))
446 return rtc;
447
448 rtc->ops = ops;
449
450 err = __devm_rtc_register_device(owner, rtc);
451 if (err)
452 return ERR_PTR(err);
453
454 return rtc;
455}
456EXPORT_SYMBOL_GPL(devm_rtc_device_register);
457
458static int __init rtc_init(void)
459{
460 rtc_class = class_create(THIS_MODULE, "rtc");
461 if (IS_ERR(rtc_class)) {
462 pr_err("couldn't create class\n");
463 return PTR_ERR(rtc_class);
464 }
465 rtc_class->pm = RTC_CLASS_DEV_PM_OPS;
466 rtc_dev_init();
467 return 0;
468}
469subsys_initcall(rtc_init);
470