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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>
18#include <linux/slab.h>
19#include <linux/workqueue.h>
20
21#include "rtc-core.h"
22
23
24static DEFINE_IDA(rtc_ida);
25struct class *rtc_class;
26
27static void rtc_device_release(struct device *dev)
28{
29 struct rtc_device *rtc = to_rtc_device(dev);
30 ida_simple_remove(&rtc_ida, rtc->id);
31 kfree(rtc);
32}
33
34#if defined(CONFIG_PM) && defined(CONFIG_RTC_HCTOSYS_DEVICE)
35
36/*
37 * On suspend(), measure the delta between one RTC and the
38 * system's wall clock; restore it on resume().
39 */
40
41static struct timespec old_rtc, old_system, old_delta;
42
43
44static int rtc_suspend(struct device *dev, pm_message_t mesg)
45{
46 struct rtc_device *rtc = to_rtc_device(dev);
47 struct rtc_time tm;
48 struct timespec delta, delta_delta;
49 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
50 return 0;
51
52 /* snapshot the current RTC and system time at suspend*/
53 rtc_read_time(rtc, &tm);
54 getnstimeofday(&old_system);
55 rtc_tm_to_time(&tm, &old_rtc.tv_sec);
56
57
58 /*
59 * To avoid drift caused by repeated suspend/resumes,
60 * which each can add ~1 second drift error,
61 * try to compensate so the difference in system time
62 * and rtc time stays close to constant.
63 */
64 delta = timespec_sub(old_system, old_rtc);
65 delta_delta = timespec_sub(delta, old_delta);
66 if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) {
67 /*
68 * if delta_delta is too large, assume time correction
69 * has occured and set old_delta to the current delta.
70 */
71 old_delta = delta;
72 } else {
73 /* Otherwise try to adjust old_system to compensate */
74 old_system = timespec_sub(old_system, delta_delta);
75 }
76
77 return 0;
78}
79
80static int rtc_resume(struct device *dev)
81{
82 struct rtc_device *rtc = to_rtc_device(dev);
83 struct rtc_time tm;
84 struct timespec new_system, new_rtc;
85 struct timespec sleep_time;
86
87 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
88 return 0;
89
90 /* snapshot the current rtc and system time at resume */
91 getnstimeofday(&new_system);
92 rtc_read_time(rtc, &tm);
93 if (rtc_valid_tm(&tm) != 0) {
94 pr_debug("%s: bogus resume time\n", dev_name(&rtc->dev));
95 return 0;
96 }
97 rtc_tm_to_time(&tm, &new_rtc.tv_sec);
98 new_rtc.tv_nsec = 0;
99
100 if (new_rtc.tv_sec < old_rtc.tv_sec) {
101 pr_debug("%s: time travel!\n", dev_name(&rtc->dev));
102 return 0;
103 }
104
105 /* calculate the RTC time delta (sleep time)*/
106 sleep_time = timespec_sub(new_rtc, old_rtc);
107
108 /*
109 * Since these RTC suspend/resume handlers are not called
110 * at the very end of suspend or the start of resume,
111 * some run-time may pass on either sides of the sleep time
112 * so subtract kernel run-time between rtc_suspend to rtc_resume
113 * to keep things accurate.
114 */
115 sleep_time = timespec_sub(sleep_time,
116 timespec_sub(new_system, old_system));
117
118 if (sleep_time.tv_sec >= 0)
119 timekeeping_inject_sleeptime(&sleep_time);
120 return 0;
121}
122
123#else
124#define rtc_suspend NULL
125#define rtc_resume NULL
126#endif
127
128
129/**
130 * rtc_device_register - register w/ RTC class
131 * @dev: the device to register
132 *
133 * rtc_device_unregister() must be called when the class device is no
134 * longer needed.
135 *
136 * Returns the pointer to the new struct class device.
137 */
138struct rtc_device *rtc_device_register(const char *name, struct device *dev,
139 const struct rtc_class_ops *ops,
140 struct module *owner)
141{
142 struct rtc_device *rtc;
143 struct rtc_wkalrm alrm;
144 int id, err;
145
146 id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL);
147 if (id < 0) {
148 err = id;
149 goto exit;
150 }
151
152 rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL);
153 if (rtc == NULL) {
154 err = -ENOMEM;
155 goto exit_ida;
156 }
157
158 rtc->id = id;
159 rtc->ops = ops;
160 rtc->owner = owner;
161 rtc->irq_freq = 1;
162 rtc->max_user_freq = 64;
163 rtc->dev.parent = dev;
164 rtc->dev.class = rtc_class;
165 rtc->dev.release = rtc_device_release;
166
167 mutex_init(&rtc->ops_lock);
168 spin_lock_init(&rtc->irq_lock);
169 spin_lock_init(&rtc->irq_task_lock);
170 init_waitqueue_head(&rtc->irq_queue);
171
172 /* Init timerqueue */
173 timerqueue_init_head(&rtc->timerqueue);
174 INIT_WORK(&rtc->irqwork, rtc_timer_do_work);
175 /* Init aie timer */
176 rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc);
177 /* Init uie timer */
178 rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc);
179 /* Init pie timer */
180 hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
181 rtc->pie_timer.function = rtc_pie_update_irq;
182 rtc->pie_enabled = 0;
183
184 /* Check to see if there is an ALARM already set in hw */
185 err = __rtc_read_alarm(rtc, &alrm);
186
187 if (!err && !rtc_valid_tm(&alrm.time))
188 rtc_initialize_alarm(rtc, &alrm);
189
190 strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE);
191 dev_set_name(&rtc->dev, "rtc%d", id);
192
193 rtc_dev_prepare(rtc);
194
195 err = device_register(&rtc->dev);
196 if (err) {
197 put_device(&rtc->dev);
198 goto exit_kfree;
199 }
200
201 rtc_dev_add_device(rtc);
202 rtc_sysfs_add_device(rtc);
203 rtc_proc_add_device(rtc);
204
205 dev_info(dev, "rtc core: registered %s as %s\n",
206 rtc->name, dev_name(&rtc->dev));
207
208 return rtc;
209
210exit_kfree:
211 kfree(rtc);
212
213exit_ida:
214 ida_simple_remove(&rtc_ida, id);
215
216exit:
217 dev_err(dev, "rtc core: unable to register %s, err = %d\n",
218 name, err);
219 return ERR_PTR(err);
220}
221EXPORT_SYMBOL_GPL(rtc_device_register);
222
223
224/**
225 * rtc_device_unregister - removes the previously registered RTC class device
226 *
227 * @rtc: the RTC class device to destroy
228 */
229void rtc_device_unregister(struct rtc_device *rtc)
230{
231 if (get_device(&rtc->dev) != NULL) {
232 mutex_lock(&rtc->ops_lock);
233 /* remove innards of this RTC, then disable it, before
234 * letting any rtc_class_open() users access it again
235 */
236 rtc_sysfs_del_device(rtc);
237 rtc_dev_del_device(rtc);
238 rtc_proc_del_device(rtc);
239 device_unregister(&rtc->dev);
240 rtc->ops = NULL;
241 mutex_unlock(&rtc->ops_lock);
242 put_device(&rtc->dev);
243 }
244}
245EXPORT_SYMBOL_GPL(rtc_device_unregister);
246
247static int __init rtc_init(void)
248{
249 rtc_class = class_create(THIS_MODULE, "rtc");
250 if (IS_ERR(rtc_class)) {
251 printk(KERN_ERR "%s: couldn't create class\n", __FILE__);
252 return PTR_ERR(rtc_class);
253 }
254 rtc_class->suspend = rtc_suspend;
255 rtc_class->resume = rtc_resume;
256 rtc_dev_init();
257 rtc_sysfs_init(rtc_class);
258 return 0;
259}
260
261static void __exit rtc_exit(void)
262{
263 rtc_dev_exit();
264 class_destroy(rtc_class);
265 ida_destroy(&rtc_ida);
266}
267
268subsys_initcall(rtc_init);
269module_exit(rtc_exit);
270
271MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
272MODULE_DESCRIPTION("RTC class support");
273MODULE_LICENSE("GPL");
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/rtc.h>
19#include <linux/kdev_t.h>
20#include <linux/idr.h>
21#include <linux/slab.h>
22#include <linux/workqueue.h>
23
24#include "rtc-core.h"
25
26
27static DEFINE_IDA(rtc_ida);
28struct class *rtc_class;
29
30static void rtc_device_release(struct device *dev)
31{
32 struct rtc_device *rtc = to_rtc_device(dev);
33 ida_simple_remove(&rtc_ida, rtc->id);
34 kfree(rtc);
35}
36
37#ifdef CONFIG_RTC_HCTOSYS_DEVICE
38/* Result of the last RTC to system clock attempt. */
39int rtc_hctosys_ret = -ENODEV;
40#endif
41
42#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE)
43/*
44 * On suspend(), measure the delta between one RTC and the
45 * system's wall clock; restore it on resume().
46 */
47
48static struct timespec64 old_rtc, old_system, old_delta;
49
50
51static int rtc_suspend(struct device *dev)
52{
53 struct rtc_device *rtc = to_rtc_device(dev);
54 struct rtc_time tm;
55 struct timespec64 delta, delta_delta;
56 int err;
57
58 if (timekeeping_rtc_skipsuspend())
59 return 0;
60
61 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
62 return 0;
63
64 /* snapshot the current RTC and system time at suspend*/
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
71 getnstimeofday64(&old_system);
72 old_rtc.tv_sec = rtc_tm_to_time64(&tm);
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 */
81 delta = timespec64_sub(old_system, old_rtc);
82 delta_delta = timespec64_sub(delta, old_delta);
83 if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) {
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 */
91 old_system = timespec64_sub(old_system, delta_delta);
92 }
93
94 return 0;
95}
96
97static int rtc_resume(struct device *dev)
98{
99 struct rtc_device *rtc = to_rtc_device(dev);
100 struct rtc_time tm;
101 struct timespec64 new_system, new_rtc;
102 struct timespec64 sleep_time;
103 int err;
104
105 if (timekeeping_rtc_skipresume())
106 return 0;
107
108 rtc_hctosys_ret = -ENODEV;
109 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
110 return 0;
111
112 /* snapshot the current rtc and system time at resume */
113 getnstimeofday64(&new_system);
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
120 new_rtc.tv_sec = rtc_tm_to_time64(&tm);
121 new_rtc.tv_nsec = 0;
122
123 if (new_rtc.tv_sec < old_rtc.tv_sec) {
124 pr_debug("%s: time travel!\n", dev_name(&rtc->dev));
125 return 0;
126 }
127
128 /* calculate the RTC time delta (sleep time)*/
129 sleep_time = timespec64_sub(new_rtc, old_rtc);
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 */
138 sleep_time = timespec64_sub(sleep_time,
139 timespec64_sub(new_system, old_system));
140
141 if (sleep_time.tv_sec >= 0)
142 timekeeping_inject_sleeptime64(&sleep_time);
143 rtc_hctosys_ret = 0;
144 return 0;
145}
146
147static 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)
149#else
150#define RTC_CLASS_DEV_PM_OPS NULL
151#endif
152
153/* Ensure the caller will set the id before releasing the device */
154static 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 /* Drivers can revise this default after allocating the device. */
165 rtc->set_offset_nsec = NSEC_PER_SEC / 2;
166
167 rtc->irq_freq = 1;
168 rtc->max_user_freq = 64;
169 rtc->dev.class = rtc_class;
170 rtc->dev.groups = rtc_get_dev_attribute_groups();
171 rtc->dev.release = rtc_device_release;
172
173 mutex_init(&rtc->ops_lock);
174 spin_lock_init(&rtc->irq_lock);
175 spin_lock_init(&rtc->irq_task_lock);
176 init_waitqueue_head(&rtc->irq_queue);
177
178 /* Init timerqueue */
179 timerqueue_init_head(&rtc->timerqueue);
180 INIT_WORK(&rtc->irqwork, rtc_timer_do_work);
181 /* Init aie timer */
182 rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc);
183 /* Init uie timer */
184 rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc);
185 /* Init pie timer */
186 hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
187 rtc->pie_timer.function = rtc_pie_update_irq;
188 rtc->pie_enabled = 0;
189
190 return rtc;
191}
192
193static int rtc_device_get_id(struct device *dev)
194{
195 int of_id = -1, id = -1;
196
197 if (dev->of_node)
198 of_id = of_alias_get_id(dev->of_node, "rtc");
199 else if (dev->parent && dev->parent->of_node)
200 of_id = of_alias_get_id(dev->parent->of_node, "rtc");
201
202 if (of_id >= 0) {
203 id = ida_simple_get(&rtc_ida, of_id, of_id + 1, GFP_KERNEL);
204 if (id < 0)
205 dev_warn(dev, "/aliases ID %d not available\n", of_id);
206 }
207
208 if (id < 0)
209 id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL);
210
211 return id;
212}
213
214static void rtc_device_get_offset(struct rtc_device *rtc)
215{
216 time64_t range_secs;
217 u32 start_year;
218 int ret;
219
220 /*
221 * If RTC driver did not implement the range of RTC hardware device,
222 * then we can not expand the RTC range by adding or subtracting one
223 * offset.
224 */
225 if (rtc->range_min == rtc->range_max)
226 return;
227
228 ret = device_property_read_u32(rtc->dev.parent, "start-year",
229 &start_year);
230 if (!ret) {
231 rtc->start_secs = mktime64(start_year, 1, 1, 0, 0, 0);
232 rtc->set_start_time = true;
233 }
234
235 /*
236 * If user did not implement the start time for RTC driver, then no
237 * need to expand the RTC range.
238 */
239 if (!rtc->set_start_time)
240 return;
241
242 range_secs = rtc->range_max - rtc->range_min + 1;
243
244 /*
245 * If the start_secs is larger than the maximum seconds (rtc->range_max)
246 * supported by RTC hardware or the maximum seconds of new expanded
247 * range (start_secs + rtc->range_max - rtc->range_min) is less than
248 * rtc->range_min, which means the minimum seconds (rtc->range_min) of
249 * RTC hardware will be mapped to start_secs by adding one offset, so
250 * the offset seconds calculation formula should be:
251 * rtc->offset_secs = rtc->start_secs - rtc->range_min;
252 *
253 * If the start_secs is larger than the minimum seconds (rtc->range_min)
254 * supported by RTC hardware, then there is one region is overlapped
255 * between the original RTC hardware range and the new expanded range,
256 * and this overlapped region do not need to be mapped into the new
257 * expanded range due to it is valid for RTC device. So the minimum
258 * seconds of RTC hardware (rtc->range_min) should be mapped to
259 * rtc->range_max + 1, then the offset seconds formula should be:
260 * rtc->offset_secs = rtc->range_max - rtc->range_min + 1;
261 *
262 * If the start_secs is less than the minimum seconds (rtc->range_min),
263 * which is similar to case 2. So the start_secs should be mapped to
264 * start_secs + rtc->range_max - rtc->range_min + 1, then the
265 * offset seconds formula should be:
266 * rtc->offset_secs = -(rtc->range_max - rtc->range_min + 1);
267 *
268 * Otherwise the offset seconds should be 0.
269 */
270 if (rtc->start_secs > rtc->range_max ||
271 rtc->start_secs + range_secs - 1 < rtc->range_min)
272 rtc->offset_secs = rtc->start_secs - rtc->range_min;
273 else if (rtc->start_secs > rtc->range_min)
274 rtc->offset_secs = range_secs;
275 else if (rtc->start_secs < rtc->range_min)
276 rtc->offset_secs = -range_secs;
277 else
278 rtc->offset_secs = 0;
279}
280
281/**
282 * rtc_device_register - register w/ RTC class
283 * @dev: the device to register
284 *
285 * rtc_device_unregister() must be called when the class device is no
286 * longer needed.
287 *
288 * Returns the pointer to the new struct class device.
289 */
290struct rtc_device *rtc_device_register(const char *name, struct device *dev,
291 const struct rtc_class_ops *ops,
292 struct module *owner)
293{
294 struct rtc_device *rtc;
295 struct rtc_wkalrm alrm;
296 int id, err;
297
298 id = rtc_device_get_id(dev);
299 if (id < 0) {
300 err = id;
301 goto exit;
302 }
303
304 rtc = rtc_allocate_device();
305 if (!rtc) {
306 err = -ENOMEM;
307 goto exit_ida;
308 }
309
310 rtc->id = id;
311 rtc->ops = ops;
312 rtc->owner = owner;
313 rtc->dev.parent = dev;
314
315 dev_set_name(&rtc->dev, "rtc%d", id);
316
317 rtc_device_get_offset(rtc);
318
319 /* Check to see if there is an ALARM already set in hw */
320 err = __rtc_read_alarm(rtc, &alrm);
321
322 if (!err && !rtc_valid_tm(&alrm.time))
323 rtc_initialize_alarm(rtc, &alrm);
324
325 rtc_dev_prepare(rtc);
326
327 err = cdev_device_add(&rtc->char_dev, &rtc->dev);
328 if (err) {
329 dev_warn(&rtc->dev, "%s: failed to add char device %d:%d\n",
330 name, MAJOR(rtc->dev.devt), rtc->id);
331
332 /* This will free both memory and the ID */
333 put_device(&rtc->dev);
334 goto exit;
335 } else {
336 dev_dbg(&rtc->dev, "%s: dev (%d:%d)\n", name,
337 MAJOR(rtc->dev.devt), rtc->id);
338 }
339
340 rtc_proc_add_device(rtc);
341
342 dev_info(dev, "rtc core: registered %s as %s\n",
343 name, dev_name(&rtc->dev));
344
345 return rtc;
346
347exit_ida:
348 ida_simple_remove(&rtc_ida, id);
349
350exit:
351 dev_err(dev, "rtc core: unable to register %s, err = %d\n",
352 name, err);
353 return ERR_PTR(err);
354}
355EXPORT_SYMBOL_GPL(rtc_device_register);
356
357
358/**
359 * rtc_device_unregister - removes the previously registered RTC class device
360 *
361 * @rtc: the RTC class device to destroy
362 */
363void rtc_device_unregister(struct rtc_device *rtc)
364{
365 mutex_lock(&rtc->ops_lock);
366 /*
367 * Remove innards of this RTC, then disable it, before
368 * letting any rtc_class_open() users access it again
369 */
370 rtc_proc_del_device(rtc);
371 cdev_device_del(&rtc->char_dev, &rtc->dev);
372 rtc->ops = NULL;
373 mutex_unlock(&rtc->ops_lock);
374 put_device(&rtc->dev);
375}
376EXPORT_SYMBOL_GPL(rtc_device_unregister);
377
378static void devm_rtc_device_release(struct device *dev, void *res)
379{
380 struct rtc_device *rtc = *(struct rtc_device **)res;
381
382 rtc_nvmem_unregister(rtc);
383 rtc_device_unregister(rtc);
384}
385
386static int devm_rtc_device_match(struct device *dev, void *res, void *data)
387{
388 struct rtc **r = res;
389
390 return *r == data;
391}
392
393/**
394 * devm_rtc_device_register - resource managed rtc_device_register()
395 * @dev: the device to register
396 * @name: the name of the device
397 * @ops: the rtc operations structure
398 * @owner: the module owner
399 *
400 * @return a struct rtc on success, or an ERR_PTR on error
401 *
402 * Managed rtc_device_register(). The rtc_device returned from this function
403 * are automatically freed on driver detach. See rtc_device_register()
404 * for more information.
405 */
406
407struct rtc_device *devm_rtc_device_register(struct device *dev,
408 const char *name,
409 const struct rtc_class_ops *ops,
410 struct module *owner)
411{
412 struct rtc_device **ptr, *rtc;
413
414 ptr = devres_alloc(devm_rtc_device_release, sizeof(*ptr), GFP_KERNEL);
415 if (!ptr)
416 return ERR_PTR(-ENOMEM);
417
418 rtc = rtc_device_register(name, dev, ops, owner);
419 if (!IS_ERR(rtc)) {
420 *ptr = rtc;
421 devres_add(dev, ptr);
422 } else {
423 devres_free(ptr);
424 }
425
426 return rtc;
427}
428EXPORT_SYMBOL_GPL(devm_rtc_device_register);
429
430/**
431 * devm_rtc_device_unregister - resource managed devm_rtc_device_unregister()
432 * @dev: the device to unregister
433 * @rtc: the RTC class device to unregister
434 *
435 * Deallocated a rtc allocated with devm_rtc_device_register(). Normally this
436 * function will not need to be called and the resource management code will
437 * ensure that the resource is freed.
438 */
439void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc)
440{
441 int rc;
442
443 rc = devres_release(dev, devm_rtc_device_release,
444 devm_rtc_device_match, rtc);
445 WARN_ON(rc);
446}
447EXPORT_SYMBOL_GPL(devm_rtc_device_unregister);
448
449static void devm_rtc_release_device(struct device *dev, void *res)
450{
451 struct rtc_device *rtc = *(struct rtc_device **)res;
452
453 rtc_nvmem_unregister(rtc);
454
455 if (rtc->registered)
456 rtc_device_unregister(rtc);
457 else
458 put_device(&rtc->dev);
459}
460
461struct rtc_device *devm_rtc_allocate_device(struct device *dev)
462{
463 struct rtc_device **ptr, *rtc;
464 int id, err;
465
466 id = rtc_device_get_id(dev);
467 if (id < 0)
468 return ERR_PTR(id);
469
470 ptr = devres_alloc(devm_rtc_release_device, sizeof(*ptr), GFP_KERNEL);
471 if (!ptr) {
472 err = -ENOMEM;
473 goto exit_ida;
474 }
475
476 rtc = rtc_allocate_device();
477 if (!rtc) {
478 err = -ENOMEM;
479 goto exit_devres;
480 }
481
482 *ptr = rtc;
483 devres_add(dev, ptr);
484
485 rtc->id = id;
486 rtc->dev.parent = dev;
487 dev_set_name(&rtc->dev, "rtc%d", id);
488
489 return rtc;
490
491exit_devres:
492 devres_free(ptr);
493exit_ida:
494 ida_simple_remove(&rtc_ida, id);
495 return ERR_PTR(err);
496}
497EXPORT_SYMBOL_GPL(devm_rtc_allocate_device);
498
499int __rtc_register_device(struct module *owner, struct rtc_device *rtc)
500{
501 struct rtc_wkalrm alrm;
502 int err;
503
504 if (!rtc->ops)
505 return -EINVAL;
506
507 rtc->owner = owner;
508 rtc_device_get_offset(rtc);
509
510 /* Check to see if there is an ALARM already set in hw */
511 err = __rtc_read_alarm(rtc, &alrm);
512 if (!err && !rtc_valid_tm(&alrm.time))
513 rtc_initialize_alarm(rtc, &alrm);
514
515 rtc_dev_prepare(rtc);
516
517 err = cdev_device_add(&rtc->char_dev, &rtc->dev);
518 if (err)
519 dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n",
520 MAJOR(rtc->dev.devt), rtc->id);
521 else
522 dev_dbg(rtc->dev.parent, "char device (%d:%d)\n",
523 MAJOR(rtc->dev.devt), rtc->id);
524
525 rtc_proc_add_device(rtc);
526
527 rtc->registered = true;
528 dev_info(rtc->dev.parent, "registered as %s\n",
529 dev_name(&rtc->dev));
530
531 return 0;
532}
533EXPORT_SYMBOL_GPL(__rtc_register_device);
534
535static int __init rtc_init(void)
536{
537 rtc_class = class_create(THIS_MODULE, "rtc");
538 if (IS_ERR(rtc_class)) {
539 pr_err("couldn't create class\n");
540 return PTR_ERR(rtc_class);
541 }
542 rtc_class->pm = RTC_CLASS_DEV_PM_OPS;
543 rtc_dev_init();
544 return 0;
545}
546subsys_initcall(rtc_init);