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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#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 timespec 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 timespec delta, delta_delta;
56
57 if (has_persistent_clock())
58 return 0;
59
60 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
61 return 0;
62
63 /* snapshot the current RTC and system time at suspend*/
64 rtc_read_time(rtc, &tm);
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);
77 if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) {
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 }
87
88 return 0;
89}
90
91static int rtc_resume(struct device *dev)
92{
93 struct rtc_device *rtc = to_rtc_device(dev);
94 struct rtc_time tm;
95 struct timespec new_system, new_rtc;
96 struct timespec sleep_time;
97
98 if (has_persistent_clock())
99 return 0;
100
101 rtc_hctosys_ret = -ENODEV;
102 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
103 return 0;
104
105 /* snapshot the current rtc and system time at resume */
106 getnstimeofday(&new_system);
107 rtc_read_time(rtc, &tm);
108 if (rtc_valid_tm(&tm) != 0) {
109 pr_debug("%s: bogus resume time\n", dev_name(&rtc->dev));
110 return 0;
111 }
112 rtc_tm_to_time(&tm, &new_rtc.tv_sec);
113 new_rtc.tv_nsec = 0;
114
115 if (new_rtc.tv_sec < old_rtc.tv_sec) {
116 pr_debug("%s: time travel!\n", dev_name(&rtc->dev));
117 return 0;
118 }
119
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));
132
133 if (sleep_time.tv_sec >= 0)
134 timekeeping_inject_sleeptime(&sleep_time);
135 rtc_hctosys_ret = 0;
136 return 0;
137}
138
139static 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)
141#else
142#define RTC_CLASS_DEV_PM_OPS NULL
143#endif
144
145
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 */
155struct rtc_device *rtc_device_register(const char *name, struct device *dev,
156 const struct rtc_class_ops *ops,
157 struct module *owner)
158{
159 struct rtc_device *rtc;
160 struct rtc_wkalrm alrm;
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 }
175
176 if (id < 0) {
177 id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL);
178 if (id < 0) {
179 err = id;
180 goto exit;
181 }
182 }
183
184 rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL);
185 if (rtc == NULL) {
186 err = -ENOMEM;
187 goto exit_ida;
188 }
189
190 rtc->id = id;
191 rtc->ops = ops;
192 rtc->owner = owner;
193 rtc->irq_freq = 1;
194 rtc->max_user_freq = 64;
195 rtc->dev.parent = dev;
196 rtc->dev.class = rtc_class;
197 rtc->dev.release = rtc_device_release;
198
199 mutex_init(&rtc->ops_lock);
200 spin_lock_init(&rtc->irq_lock);
201 spin_lock_init(&rtc->irq_task_lock);
202 init_waitqueue_head(&rtc->irq_queue);
203
204 /* Init timerqueue */
205 timerqueue_init_head(&rtc->timerqueue);
206 INIT_WORK(&rtc->irqwork, rtc_timer_do_work);
207 /* Init aie timer */
208 rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc);
209 /* Init uie timer */
210 rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc);
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
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))
220 rtc_initialize_alarm(rtc, &alrm);
221
222 strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE);
223 dev_set_name(&rtc->dev, "rtc%d", id);
224
225 rtc_dev_prepare(rtc);
226
227 err = device_register(&rtc->dev);
228 if (err) {
229 put_device(&rtc->dev);
230 goto exit_kfree;
231 }
232
233 rtc_dev_add_device(rtc);
234 rtc_sysfs_add_device(rtc);
235 rtc_proc_add_device(rtc);
236
237 dev_info(dev, "rtc core: registered %s as %s\n",
238 rtc->name, dev_name(&rtc->dev));
239
240 return rtc;
241
242exit_kfree:
243 kfree(rtc);
244
245exit_ida:
246 ida_simple_remove(&rtc_ida, id);
247
248exit:
249 dev_err(dev, "rtc core: unable to register %s, err = %d\n",
250 name, err);
251 return ERR_PTR(err);
252}
253EXPORT_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 */
261void rtc_device_unregister(struct rtc_device *rtc)
262{
263 if (get_device(&rtc->dev) != NULL) {
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 */
268 rtc_sysfs_del_device(rtc);
269 rtc_dev_del_device(rtc);
270 rtc_proc_del_device(rtc);
271 device_unregister(&rtc->dev);
272 rtc->ops = NULL;
273 mutex_unlock(&rtc->ops_lock);
274 put_device(&rtc->dev);
275 }
276}
277EXPORT_SYMBOL_GPL(rtc_device_unregister);
278
279static 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
286static 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()
295 * @dev: the device to register
296 * @name: the name of the device
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
307struct rtc_device *devm_rtc_device_register(struct device *dev,
308 const char *name,
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}
328EXPORT_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 */
339void 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}
347EXPORT_SYMBOL_GPL(devm_rtc_device_unregister);
348
349static int __init rtc_init(void)
350{
351 rtc_class = class_create(THIS_MODULE, "rtc");
352 if (IS_ERR(rtc_class)) {
353 pr_err("couldn't create class\n");
354 return PTR_ERR(rtc_class);
355 }
356 rtc_class->pm = RTC_CLASS_DEV_PM_OPS;
357 rtc_dev_init();
358 rtc_sysfs_init(rtc_class);
359 return 0;
360}
361
362static void __exit rtc_exit(void)
363{
364 rtc_dev_exit();
365 class_destroy(rtc_class);
366 ida_destroy(&rtc_ida);
367}
368
369subsys_initcall(rtc_init);
370module_exit(rtc_exit);
371
372MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
373MODULE_DESCRIPTION("RTC class support");
374MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * RTC subsystem, base class
4 *
5 * Copyright (C) 2005 Tower Technologies
6 * Author: Alessandro Zummo <a.zummo@towertech.it>
7 *
8 * class skeleton from drivers/hwmon/hwmon.c
9 */
10
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 kfree(rtc);
32}
33
34#ifdef CONFIG_RTC_HCTOSYS_DEVICE
35/* Result of the last RTC to system clock attempt. */
36int rtc_hctosys_ret = -ENODEV;
37#endif
38
39#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE)
40/*
41 * On suspend(), measure the delta between one RTC and the
42 * system's wall clock; restore it on resume().
43 */
44
45static struct timespec64 old_rtc, old_system, old_delta;
46
47static int rtc_suspend(struct device *dev)
48{
49 struct rtc_device *rtc = to_rtc_device(dev);
50 struct rtc_time tm;
51 struct timespec64 delta, delta_delta;
52 int err;
53
54 if (timekeeping_rtc_skipsuspend())
55 return 0;
56
57 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
58 return 0;
59
60 /* snapshot the current RTC and system time at suspend*/
61 err = rtc_read_time(rtc, &tm);
62 if (err < 0) {
63 pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev));
64 return 0;
65 }
66
67 ktime_get_real_ts64(&old_system);
68 old_rtc.tv_sec = rtc_tm_to_time64(&tm);
69
70 /*
71 * To avoid drift caused by repeated suspend/resumes,
72 * which each can add ~1 second drift error,
73 * try to compensate so the difference in system time
74 * and rtc time stays close to constant.
75 */
76 delta = timespec64_sub(old_system, old_rtc);
77 delta_delta = timespec64_sub(delta, old_delta);
78 if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) {
79 /*
80 * if delta_delta is too large, assume time correction
81 * has occurred and set old_delta to the current delta.
82 */
83 old_delta = delta;
84 } else {
85 /* Otherwise try to adjust old_system to compensate */
86 old_system = timespec64_sub(old_system, delta_delta);
87 }
88
89 return 0;
90}
91
92static int rtc_resume(struct device *dev)
93{
94 struct rtc_device *rtc = to_rtc_device(dev);
95 struct rtc_time tm;
96 struct timespec64 new_system, new_rtc;
97 struct timespec64 sleep_time;
98 int err;
99
100 if (timekeeping_rtc_skipresume())
101 return 0;
102
103 rtc_hctosys_ret = -ENODEV;
104 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
105 return 0;
106
107 /* snapshot the current rtc and system time at resume */
108 ktime_get_real_ts64(&new_system);
109 err = rtc_read_time(rtc, &tm);
110 if (err < 0) {
111 pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev));
112 return 0;
113 }
114
115 new_rtc.tv_sec = rtc_tm_to_time64(&tm);
116 new_rtc.tv_nsec = 0;
117
118 if (new_rtc.tv_sec < old_rtc.tv_sec) {
119 pr_debug("%s: time travel!\n", dev_name(&rtc->dev));
120 return 0;
121 }
122
123 /* calculate the RTC time delta (sleep time)*/
124 sleep_time = timespec64_sub(new_rtc, old_rtc);
125
126 /*
127 * Since these RTC suspend/resume handlers are not called
128 * at the very end of suspend or the start of resume,
129 * some run-time may pass on either sides of the sleep time
130 * so subtract kernel run-time between rtc_suspend to rtc_resume
131 * to keep things accurate.
132 */
133 sleep_time = timespec64_sub(sleep_time,
134 timespec64_sub(new_system, old_system));
135
136 if (sleep_time.tv_sec >= 0)
137 timekeeping_inject_sleeptime64(&sleep_time);
138 rtc_hctosys_ret = 0;
139 return 0;
140}
141
142static SIMPLE_DEV_PM_OPS(rtc_class_dev_pm_ops, rtc_suspend, rtc_resume);
143#define RTC_CLASS_DEV_PM_OPS (&rtc_class_dev_pm_ops)
144#else
145#define RTC_CLASS_DEV_PM_OPS NULL
146#endif
147
148/* Ensure the caller will set the id before releasing the device */
149static struct rtc_device *rtc_allocate_device(void)
150{
151 struct rtc_device *rtc;
152
153 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
154 if (!rtc)
155 return NULL;
156
157 device_initialize(&rtc->dev);
158
159 /* Drivers can revise this default after allocating the device. */
160 rtc->set_offset_nsec = NSEC_PER_SEC / 2;
161
162 rtc->irq_freq = 1;
163 rtc->max_user_freq = 64;
164 rtc->dev.class = rtc_class;
165 rtc->dev.groups = rtc_get_dev_attribute_groups();
166 rtc->dev.release = rtc_device_release;
167
168 mutex_init(&rtc->ops_lock);
169 spin_lock_init(&rtc->irq_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, rtc);
177 /* Init uie timer */
178 rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, 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 return rtc;
185}
186
187static int rtc_device_get_id(struct device *dev)
188{
189 int of_id = -1, id = -1;
190
191 if (dev->of_node)
192 of_id = of_alias_get_id(dev->of_node, "rtc");
193 else if (dev->parent && dev->parent->of_node)
194 of_id = of_alias_get_id(dev->parent->of_node, "rtc");
195
196 if (of_id >= 0) {
197 id = ida_simple_get(&rtc_ida, of_id, of_id + 1, GFP_KERNEL);
198 if (id < 0)
199 dev_warn(dev, "/aliases ID %d not available\n", of_id);
200 }
201
202 if (id < 0)
203 id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL);
204
205 return id;
206}
207
208static void rtc_device_get_offset(struct rtc_device *rtc)
209{
210 time64_t range_secs;
211 u32 start_year;
212 int ret;
213
214 /*
215 * If RTC driver did not implement the range of RTC hardware device,
216 * then we can not expand the RTC range by adding or subtracting one
217 * offset.
218 */
219 if (rtc->range_min == rtc->range_max)
220 return;
221
222 ret = device_property_read_u32(rtc->dev.parent, "start-year",
223 &start_year);
224 if (!ret) {
225 rtc->start_secs = mktime64(start_year, 1, 1, 0, 0, 0);
226 rtc->set_start_time = true;
227 }
228
229 /*
230 * If user did not implement the start time for RTC driver, then no
231 * need to expand the RTC range.
232 */
233 if (!rtc->set_start_time)
234 return;
235
236 range_secs = rtc->range_max - rtc->range_min + 1;
237
238 /*
239 * If the start_secs is larger than the maximum seconds (rtc->range_max)
240 * supported by RTC hardware or the maximum seconds of new expanded
241 * range (start_secs + rtc->range_max - rtc->range_min) is less than
242 * rtc->range_min, which means the minimum seconds (rtc->range_min) of
243 * RTC hardware will be mapped to start_secs by adding one offset, so
244 * the offset seconds calculation formula should be:
245 * rtc->offset_secs = rtc->start_secs - rtc->range_min;
246 *
247 * If the start_secs is larger than the minimum seconds (rtc->range_min)
248 * supported by RTC hardware, then there is one region is overlapped
249 * between the original RTC hardware range and the new expanded range,
250 * and this overlapped region do not need to be mapped into the new
251 * expanded range due to it is valid for RTC device. So the minimum
252 * seconds of RTC hardware (rtc->range_min) should be mapped to
253 * rtc->range_max + 1, then the offset seconds formula should be:
254 * rtc->offset_secs = rtc->range_max - rtc->range_min + 1;
255 *
256 * If the start_secs is less than the minimum seconds (rtc->range_min),
257 * which is similar to case 2. So the start_secs should be mapped to
258 * start_secs + rtc->range_max - rtc->range_min + 1, then the
259 * offset seconds formula should be:
260 * rtc->offset_secs = -(rtc->range_max - rtc->range_min + 1);
261 *
262 * Otherwise the offset seconds should be 0.
263 */
264 if (rtc->start_secs > rtc->range_max ||
265 rtc->start_secs + range_secs - 1 < rtc->range_min)
266 rtc->offset_secs = rtc->start_secs - rtc->range_min;
267 else if (rtc->start_secs > rtc->range_min)
268 rtc->offset_secs = range_secs;
269 else if (rtc->start_secs < rtc->range_min)
270 rtc->offset_secs = -range_secs;
271 else
272 rtc->offset_secs = 0;
273}
274
275/**
276 * rtc_device_unregister - removes the previously registered RTC class device
277 *
278 * @rtc: the RTC class device to destroy
279 */
280static void rtc_device_unregister(struct rtc_device *rtc)
281{
282 mutex_lock(&rtc->ops_lock);
283 /*
284 * Remove innards of this RTC, then disable it, before
285 * letting any rtc_class_open() users access it again
286 */
287 rtc_proc_del_device(rtc);
288 cdev_device_del(&rtc->char_dev, &rtc->dev);
289 rtc->ops = NULL;
290 mutex_unlock(&rtc->ops_lock);
291 put_device(&rtc->dev);
292}
293
294static void devm_rtc_release_device(struct device *dev, void *res)
295{
296 struct rtc_device *rtc = *(struct rtc_device **)res;
297
298 rtc_nvmem_unregister(rtc);
299
300 if (rtc->registered)
301 rtc_device_unregister(rtc);
302 else
303 put_device(&rtc->dev);
304}
305
306struct rtc_device *devm_rtc_allocate_device(struct device *dev)
307{
308 struct rtc_device **ptr, *rtc;
309 int id, err;
310
311 id = rtc_device_get_id(dev);
312 if (id < 0)
313 return ERR_PTR(id);
314
315 ptr = devres_alloc(devm_rtc_release_device, sizeof(*ptr), GFP_KERNEL);
316 if (!ptr) {
317 err = -ENOMEM;
318 goto exit_ida;
319 }
320
321 rtc = rtc_allocate_device();
322 if (!rtc) {
323 err = -ENOMEM;
324 goto exit_devres;
325 }
326
327 *ptr = rtc;
328 devres_add(dev, ptr);
329
330 rtc->id = id;
331 rtc->dev.parent = dev;
332 dev_set_name(&rtc->dev, "rtc%d", id);
333
334 return rtc;
335
336exit_devres:
337 devres_free(ptr);
338exit_ida:
339 ida_simple_remove(&rtc_ida, id);
340 return ERR_PTR(err);
341}
342EXPORT_SYMBOL_GPL(devm_rtc_allocate_device);
343
344int __rtc_register_device(struct module *owner, struct rtc_device *rtc)
345{
346 struct rtc_wkalrm alrm;
347 int err;
348
349 if (!rtc->ops) {
350 dev_dbg(&rtc->dev, "no ops set\n");
351 return -EINVAL;
352 }
353
354 rtc->owner = owner;
355 rtc_device_get_offset(rtc);
356
357 /* Check to see if there is an ALARM already set in hw */
358 err = __rtc_read_alarm(rtc, &alrm);
359 if (!err && !rtc_valid_tm(&alrm.time))
360 rtc_initialize_alarm(rtc, &alrm);
361
362 rtc_dev_prepare(rtc);
363
364 err = cdev_device_add(&rtc->char_dev, &rtc->dev);
365 if (err)
366 dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n",
367 MAJOR(rtc->dev.devt), rtc->id);
368 else
369 dev_dbg(rtc->dev.parent, "char device (%d:%d)\n",
370 MAJOR(rtc->dev.devt), rtc->id);
371
372 rtc_proc_add_device(rtc);
373
374 rtc->registered = true;
375 dev_info(rtc->dev.parent, "registered as %s\n",
376 dev_name(&rtc->dev));
377
378 return 0;
379}
380EXPORT_SYMBOL_GPL(__rtc_register_device);
381
382/**
383 * devm_rtc_device_register - resource managed rtc_device_register()
384 * @dev: the device to register
385 * @name: the name of the device (unused)
386 * @ops: the rtc operations structure
387 * @owner: the module owner
388 *
389 * @return a struct rtc on success, or an ERR_PTR on error
390 *
391 * Managed rtc_device_register(). The rtc_device returned from this function
392 * are automatically freed on driver detach.
393 * This function is deprecated, use devm_rtc_allocate_device and
394 * rtc_register_device instead
395 */
396struct rtc_device *devm_rtc_device_register(struct device *dev,
397 const char *name,
398 const struct rtc_class_ops *ops,
399 struct module *owner)
400{
401 struct rtc_device *rtc;
402 int err;
403
404 rtc = devm_rtc_allocate_device(dev);
405 if (IS_ERR(rtc))
406 return rtc;
407
408 rtc->ops = ops;
409
410 err = __rtc_register_device(owner, rtc);
411 if (err)
412 return ERR_PTR(err);
413
414 return rtc;
415}
416EXPORT_SYMBOL_GPL(devm_rtc_device_register);
417
418static int __init rtc_init(void)
419{
420 rtc_class = class_create(THIS_MODULE, "rtc");
421 if (IS_ERR(rtc_class)) {
422 pr_err("couldn't create class\n");
423 return PTR_ERR(rtc_class);
424 }
425 rtc_class->pm = RTC_CLASS_DEV_PM_OPS;
426 rtc_dev_init();
427 return 0;
428}
429subsys_initcall(rtc_init);