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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 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
154/**
155 * rtc_device_register - register w/ RTC class
156 * @dev: the device to register
157 *
158 * rtc_device_unregister() must be called when the class device is no
159 * longer needed.
160 *
161 * Returns the pointer to the new struct class device.
162 */
163struct rtc_device *rtc_device_register(const char *name, struct device *dev,
164 const struct rtc_class_ops *ops,
165 struct module *owner)
166{
167 struct rtc_device *rtc;
168 struct rtc_wkalrm alrm;
169 int of_id = -1, id = -1, err;
170
171 if (dev->of_node)
172 of_id = of_alias_get_id(dev->of_node, "rtc");
173 else if (dev->parent && dev->parent->of_node)
174 of_id = of_alias_get_id(dev->parent->of_node, "rtc");
175
176 if (of_id >= 0) {
177 id = ida_simple_get(&rtc_ida, of_id, of_id + 1,
178 GFP_KERNEL);
179 if (id < 0)
180 dev_warn(dev, "/aliases ID %d not available\n",
181 of_id);
182 }
183
184 if (id < 0) {
185 id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL);
186 if (id < 0) {
187 err = id;
188 goto exit;
189 }
190 }
191
192 rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL);
193 if (rtc == NULL) {
194 err = -ENOMEM;
195 goto exit_ida;
196 }
197
198 rtc->id = id;
199 rtc->ops = ops;
200 rtc->owner = owner;
201 rtc->irq_freq = 1;
202 rtc->max_user_freq = 64;
203 rtc->dev.parent = dev;
204 rtc->dev.class = rtc_class;
205 rtc->dev.groups = rtc_get_dev_attribute_groups();
206 rtc->dev.release = rtc_device_release;
207
208 mutex_init(&rtc->ops_lock);
209 spin_lock_init(&rtc->irq_lock);
210 spin_lock_init(&rtc->irq_task_lock);
211 init_waitqueue_head(&rtc->irq_queue);
212
213 /* Init timerqueue */
214 timerqueue_init_head(&rtc->timerqueue);
215 INIT_WORK(&rtc->irqwork, rtc_timer_do_work);
216 /* Init aie timer */
217 rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc);
218 /* Init uie timer */
219 rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc);
220 /* Init pie timer */
221 hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
222 rtc->pie_timer.function = rtc_pie_update_irq;
223 rtc->pie_enabled = 0;
224
225 strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE);
226 dev_set_name(&rtc->dev, "rtc%d", id);
227
228 /* Check to see if there is an ALARM already set in hw */
229 err = __rtc_read_alarm(rtc, &alrm);
230
231 if (!err && !rtc_valid_tm(&alrm.time))
232 rtc_initialize_alarm(rtc, &alrm);
233
234 rtc_dev_prepare(rtc);
235
236 err = device_register(&rtc->dev);
237 if (err) {
238 /* This will free both memory and the ID */
239 put_device(&rtc->dev);
240 goto exit;
241 }
242
243 rtc_dev_add_device(rtc);
244 rtc_proc_add_device(rtc);
245
246 dev_info(dev, "rtc core: registered %s as %s\n",
247 rtc->name, dev_name(&rtc->dev));
248
249 return rtc;
250
251exit_ida:
252 ida_simple_remove(&rtc_ida, id);
253
254exit:
255 dev_err(dev, "rtc core: unable to register %s, err = %d\n",
256 name, err);
257 return ERR_PTR(err);
258}
259EXPORT_SYMBOL_GPL(rtc_device_register);
260
261
262/**
263 * rtc_device_unregister - removes the previously registered RTC class device
264 *
265 * @rtc: the RTC class device to destroy
266 */
267void rtc_device_unregister(struct rtc_device *rtc)
268{
269 mutex_lock(&rtc->ops_lock);
270 /*
271 * Remove innards of this RTC, then disable it, before
272 * letting any rtc_class_open() users access it again
273 */
274 rtc_dev_del_device(rtc);
275 rtc_proc_del_device(rtc);
276 device_del(&rtc->dev);
277 rtc->ops = NULL;
278 mutex_unlock(&rtc->ops_lock);
279 put_device(&rtc->dev);
280}
281EXPORT_SYMBOL_GPL(rtc_device_unregister);
282
283static void devm_rtc_device_release(struct device *dev, void *res)
284{
285 struct rtc_device *rtc = *(struct rtc_device **)res;
286
287 rtc_device_unregister(rtc);
288}
289
290static int devm_rtc_device_match(struct device *dev, void *res, void *data)
291{
292 struct rtc **r = res;
293
294 return *r == data;
295}
296
297/**
298 * devm_rtc_device_register - resource managed rtc_device_register()
299 * @dev: the device to register
300 * @name: the name of the device
301 * @ops: the rtc operations structure
302 * @owner: the module owner
303 *
304 * @return a struct rtc on success, or an ERR_PTR on error
305 *
306 * Managed rtc_device_register(). The rtc_device returned from this function
307 * are automatically freed on driver detach. See rtc_device_register()
308 * for more information.
309 */
310
311struct rtc_device *devm_rtc_device_register(struct device *dev,
312 const char *name,
313 const struct rtc_class_ops *ops,
314 struct module *owner)
315{
316 struct rtc_device **ptr, *rtc;
317
318 ptr = devres_alloc(devm_rtc_device_release, sizeof(*ptr), GFP_KERNEL);
319 if (!ptr)
320 return ERR_PTR(-ENOMEM);
321
322 rtc = rtc_device_register(name, dev, ops, owner);
323 if (!IS_ERR(rtc)) {
324 *ptr = rtc;
325 devres_add(dev, ptr);
326 } else {
327 devres_free(ptr);
328 }
329
330 return rtc;
331}
332EXPORT_SYMBOL_GPL(devm_rtc_device_register);
333
334/**
335 * devm_rtc_device_unregister - resource managed devm_rtc_device_unregister()
336 * @dev: the device to unregister
337 * @rtc: the RTC class device to unregister
338 *
339 * Deallocated a rtc allocated with devm_rtc_device_register(). Normally this
340 * function will not need to be called and the resource management code will
341 * ensure that the resource is freed.
342 */
343void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc)
344{
345 int rc;
346
347 rc = devres_release(dev, devm_rtc_device_release,
348 devm_rtc_device_match, rtc);
349 WARN_ON(rc);
350}
351EXPORT_SYMBOL_GPL(devm_rtc_device_unregister);
352
353static int __init rtc_init(void)
354{
355 rtc_class = class_create(THIS_MODULE, "rtc");
356 if (IS_ERR(rtc_class)) {
357 pr_err("couldn't create class\n");
358 return PTR_ERR(rtc_class);
359 }
360 rtc_class->pm = RTC_CLASS_DEV_PM_OPS;
361 rtc_dev_init();
362 return 0;
363}
364subsys_initcall(rtc_init);
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
38/* IMPORTANT: the RTC only stores whole seconds. It is arbitrary
39 * whether it stores the most close value or the value with partial
40 * seconds truncated. However, it is important that we use it to store
41 * the truncated value. This is because otherwise it is necessary,
42 * in an rtc sync function, to read both xtime.tv_sec and
43 * xtime.tv_nsec. On some processors (i.e. ARM), an atomic read
44 * of >32bits is not possible. So storing the most close value would
45 * slow down the sync API. So here we have the truncated value and
46 * the best guess is to add 0.5s.
47 */
48
49static void rtc_hctosys(struct rtc_device *rtc)
50{
51 int err;
52 struct rtc_time tm;
53 struct timespec64 tv64 = {
54 .tv_nsec = NSEC_PER_SEC >> 1,
55 };
56
57 err = rtc_read_time(rtc, &tm);
58 if (err) {
59 dev_err(rtc->dev.parent,
60 "hctosys: unable to read the hardware clock\n");
61 goto err_read;
62 }
63
64 tv64.tv_sec = rtc_tm_to_time64(&tm);
65
66#if BITS_PER_LONG == 32
67 if (tv64.tv_sec > INT_MAX) {
68 err = -ERANGE;
69 goto err_read;
70 }
71#endif
72
73 err = do_settimeofday64(&tv64);
74
75 dev_info(rtc->dev.parent, "setting system clock to %ptR UTC (%lld)\n",
76 &tm, (long long)tv64.tv_sec);
77
78err_read:
79 rtc_hctosys_ret = err;
80}
81#endif
82
83#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE)
84/*
85 * On suspend(), measure the delta between one RTC and the
86 * system's wall clock; restore it on resume().
87 */
88
89static struct timespec64 old_rtc, old_system, old_delta;
90
91static int rtc_suspend(struct device *dev)
92{
93 struct rtc_device *rtc = to_rtc_device(dev);
94 struct rtc_time tm;
95 struct timespec64 delta, delta_delta;
96 int err;
97
98 if (timekeeping_rtc_skipsuspend())
99 return 0;
100
101 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
102 return 0;
103
104 /* snapshot the current RTC and system time at suspend*/
105 err = rtc_read_time(rtc, &tm);
106 if (err < 0) {
107 pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev));
108 return 0;
109 }
110
111 ktime_get_real_ts64(&old_system);
112 old_rtc.tv_sec = rtc_tm_to_time64(&tm);
113
114 /*
115 * To avoid drift caused by repeated suspend/resumes,
116 * which each can add ~1 second drift error,
117 * try to compensate so the difference in system time
118 * and rtc time stays close to constant.
119 */
120 delta = timespec64_sub(old_system, old_rtc);
121 delta_delta = timespec64_sub(delta, old_delta);
122 if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) {
123 /*
124 * if delta_delta is too large, assume time correction
125 * has occurred and set old_delta to the current delta.
126 */
127 old_delta = delta;
128 } else {
129 /* Otherwise try to adjust old_system to compensate */
130 old_system = timespec64_sub(old_system, delta_delta);
131 }
132
133 return 0;
134}
135
136static int rtc_resume(struct device *dev)
137{
138 struct rtc_device *rtc = to_rtc_device(dev);
139 struct rtc_time tm;
140 struct timespec64 new_system, new_rtc;
141 struct timespec64 sleep_time;
142 int err;
143
144 if (timekeeping_rtc_skipresume())
145 return 0;
146
147 rtc_hctosys_ret = -ENODEV;
148 if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
149 return 0;
150
151 /* snapshot the current rtc and system time at resume */
152 ktime_get_real_ts64(&new_system);
153 err = rtc_read_time(rtc, &tm);
154 if (err < 0) {
155 pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev));
156 return 0;
157 }
158
159 new_rtc.tv_sec = rtc_tm_to_time64(&tm);
160 new_rtc.tv_nsec = 0;
161
162 if (new_rtc.tv_sec < old_rtc.tv_sec) {
163 pr_debug("%s: time travel!\n", dev_name(&rtc->dev));
164 return 0;
165 }
166
167 /* calculate the RTC time delta (sleep time)*/
168 sleep_time = timespec64_sub(new_rtc, old_rtc);
169
170 /*
171 * Since these RTC suspend/resume handlers are not called
172 * at the very end of suspend or the start of resume,
173 * some run-time may pass on either sides of the sleep time
174 * so subtract kernel run-time between rtc_suspend to rtc_resume
175 * to keep things accurate.
176 */
177 sleep_time = timespec64_sub(sleep_time,
178 timespec64_sub(new_system, old_system));
179
180 if (sleep_time.tv_sec >= 0)
181 timekeeping_inject_sleeptime64(&sleep_time);
182 rtc_hctosys_ret = 0;
183 return 0;
184}
185
186static SIMPLE_DEV_PM_OPS(rtc_class_dev_pm_ops, rtc_suspend, rtc_resume);
187#define RTC_CLASS_DEV_PM_OPS (&rtc_class_dev_pm_ops)
188#else
189#define RTC_CLASS_DEV_PM_OPS NULL
190#endif
191
192/* Ensure the caller will set the id before releasing the device */
193static struct rtc_device *rtc_allocate_device(void)
194{
195 struct rtc_device *rtc;
196
197 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
198 if (!rtc)
199 return NULL;
200
201 device_initialize(&rtc->dev);
202
203 /* Drivers can revise this default after allocating the device. */
204 rtc->set_offset_nsec = NSEC_PER_SEC / 2;
205
206 rtc->irq_freq = 1;
207 rtc->max_user_freq = 64;
208 rtc->dev.class = rtc_class;
209 rtc->dev.groups = rtc_get_dev_attribute_groups();
210 rtc->dev.release = rtc_device_release;
211
212 mutex_init(&rtc->ops_lock);
213 spin_lock_init(&rtc->irq_lock);
214 init_waitqueue_head(&rtc->irq_queue);
215
216 /* Init timerqueue */
217 timerqueue_init_head(&rtc->timerqueue);
218 INIT_WORK(&rtc->irqwork, rtc_timer_do_work);
219 /* Init aie timer */
220 rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, rtc);
221 /* Init uie timer */
222 rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, rtc);
223 /* Init pie timer */
224 hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
225 rtc->pie_timer.function = rtc_pie_update_irq;
226 rtc->pie_enabled = 0;
227
228 return rtc;
229}
230
231static int rtc_device_get_id(struct device *dev)
232{
233 int of_id = -1, id = -1;
234
235 if (dev->of_node)
236 of_id = of_alias_get_id(dev->of_node, "rtc");
237 else if (dev->parent && dev->parent->of_node)
238 of_id = of_alias_get_id(dev->parent->of_node, "rtc");
239
240 if (of_id >= 0) {
241 id = ida_simple_get(&rtc_ida, of_id, of_id + 1, GFP_KERNEL);
242 if (id < 0)
243 dev_warn(dev, "/aliases ID %d not available\n", of_id);
244 }
245
246 if (id < 0)
247 id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL);
248
249 return id;
250}
251
252static void rtc_device_get_offset(struct rtc_device *rtc)
253{
254 time64_t range_secs;
255 u32 start_year;
256 int ret;
257
258 /*
259 * If RTC driver did not implement the range of RTC hardware device,
260 * then we can not expand the RTC range by adding or subtracting one
261 * offset.
262 */
263 if (rtc->range_min == rtc->range_max)
264 return;
265
266 ret = device_property_read_u32(rtc->dev.parent, "start-year",
267 &start_year);
268 if (!ret) {
269 rtc->start_secs = mktime64(start_year, 1, 1, 0, 0, 0);
270 rtc->set_start_time = true;
271 }
272
273 /*
274 * If user did not implement the start time for RTC driver, then no
275 * need to expand the RTC range.
276 */
277 if (!rtc->set_start_time)
278 return;
279
280 range_secs = rtc->range_max - rtc->range_min + 1;
281
282 /*
283 * If the start_secs is larger than the maximum seconds (rtc->range_max)
284 * supported by RTC hardware or the maximum seconds of new expanded
285 * range (start_secs + rtc->range_max - rtc->range_min) is less than
286 * rtc->range_min, which means the minimum seconds (rtc->range_min) of
287 * RTC hardware will be mapped to start_secs by adding one offset, so
288 * the offset seconds calculation formula should be:
289 * rtc->offset_secs = rtc->start_secs - rtc->range_min;
290 *
291 * If the start_secs is larger than the minimum seconds (rtc->range_min)
292 * supported by RTC hardware, then there is one region is overlapped
293 * between the original RTC hardware range and the new expanded range,
294 * and this overlapped region do not need to be mapped into the new
295 * expanded range due to it is valid for RTC device. So the minimum
296 * seconds of RTC hardware (rtc->range_min) should be mapped to
297 * rtc->range_max + 1, then the offset seconds formula should be:
298 * rtc->offset_secs = rtc->range_max - rtc->range_min + 1;
299 *
300 * If the start_secs is less than the minimum seconds (rtc->range_min),
301 * which is similar to case 2. So the start_secs should be mapped to
302 * start_secs + rtc->range_max - rtc->range_min + 1, then the
303 * offset seconds formula should be:
304 * rtc->offset_secs = -(rtc->range_max - rtc->range_min + 1);
305 *
306 * Otherwise the offset seconds should be 0.
307 */
308 if (rtc->start_secs > rtc->range_max ||
309 rtc->start_secs + range_secs - 1 < rtc->range_min)
310 rtc->offset_secs = rtc->start_secs - rtc->range_min;
311 else if (rtc->start_secs > rtc->range_min)
312 rtc->offset_secs = range_secs;
313 else if (rtc->start_secs < rtc->range_min)
314 rtc->offset_secs = -range_secs;
315 else
316 rtc->offset_secs = 0;
317}
318
319/**
320 * rtc_device_unregister - removes the previously registered RTC class device
321 *
322 * @rtc: the RTC class device to destroy
323 */
324static void rtc_device_unregister(struct rtc_device *rtc)
325{
326 mutex_lock(&rtc->ops_lock);
327 /*
328 * Remove innards of this RTC, then disable it, before
329 * letting any rtc_class_open() users access it again
330 */
331 rtc_proc_del_device(rtc);
332 cdev_device_del(&rtc->char_dev, &rtc->dev);
333 rtc->ops = NULL;
334 mutex_unlock(&rtc->ops_lock);
335 put_device(&rtc->dev);
336}
337
338static void devm_rtc_release_device(struct device *dev, void *res)
339{
340 struct rtc_device *rtc = *(struct rtc_device **)res;
341
342 rtc_nvmem_unregister(rtc);
343
344 if (rtc->registered)
345 rtc_device_unregister(rtc);
346 else
347 put_device(&rtc->dev);
348}
349
350struct rtc_device *devm_rtc_allocate_device(struct device *dev)
351{
352 struct rtc_device **ptr, *rtc;
353 int id, err;
354
355 id = rtc_device_get_id(dev);
356 if (id < 0)
357 return ERR_PTR(id);
358
359 ptr = devres_alloc(devm_rtc_release_device, sizeof(*ptr), GFP_KERNEL);
360 if (!ptr) {
361 err = -ENOMEM;
362 goto exit_ida;
363 }
364
365 rtc = rtc_allocate_device();
366 if (!rtc) {
367 err = -ENOMEM;
368 goto exit_devres;
369 }
370
371 *ptr = rtc;
372 devres_add(dev, ptr);
373
374 rtc->id = id;
375 rtc->dev.parent = dev;
376 dev_set_name(&rtc->dev, "rtc%d", id);
377
378 return rtc;
379
380exit_devres:
381 devres_free(ptr);
382exit_ida:
383 ida_simple_remove(&rtc_ida, id);
384 return ERR_PTR(err);
385}
386EXPORT_SYMBOL_GPL(devm_rtc_allocate_device);
387
388int __rtc_register_device(struct module *owner, struct rtc_device *rtc)
389{
390 struct rtc_wkalrm alrm;
391 int err;
392
393 if (!rtc->ops) {
394 dev_dbg(&rtc->dev, "no ops set\n");
395 return -EINVAL;
396 }
397
398 rtc->owner = owner;
399 rtc_device_get_offset(rtc);
400
401 /* Check to see if there is an ALARM already set in hw */
402 err = __rtc_read_alarm(rtc, &alrm);
403 if (!err && !rtc_valid_tm(&alrm.time))
404 rtc_initialize_alarm(rtc, &alrm);
405
406 rtc_dev_prepare(rtc);
407
408 err = cdev_device_add(&rtc->char_dev, &rtc->dev);
409 if (err)
410 dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n",
411 MAJOR(rtc->dev.devt), rtc->id);
412 else
413 dev_dbg(rtc->dev.parent, "char device (%d:%d)\n",
414 MAJOR(rtc->dev.devt), rtc->id);
415
416 rtc_proc_add_device(rtc);
417
418 rtc->registered = true;
419 dev_info(rtc->dev.parent, "registered as %s\n",
420 dev_name(&rtc->dev));
421
422#ifdef CONFIG_RTC_HCTOSYS_DEVICE
423 if (!strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE))
424 rtc_hctosys(rtc);
425#endif
426
427 return 0;
428}
429EXPORT_SYMBOL_GPL(__rtc_register_device);
430
431/**
432 * devm_rtc_device_register - resource managed rtc_device_register()
433 * @dev: the device to register
434 * @name: the name of the device (unused)
435 * @ops: the rtc operations structure
436 * @owner: the module owner
437 *
438 * @return a struct rtc on success, or an ERR_PTR on error
439 *
440 * Managed rtc_device_register(). The rtc_device returned from this function
441 * are automatically freed on driver detach.
442 * This function is deprecated, use devm_rtc_allocate_device and
443 * rtc_register_device instead
444 */
445struct rtc_device *devm_rtc_device_register(struct device *dev,
446 const char *name,
447 const struct rtc_class_ops *ops,
448 struct module *owner)
449{
450 struct rtc_device *rtc;
451 int err;
452
453 rtc = devm_rtc_allocate_device(dev);
454 if (IS_ERR(rtc))
455 return rtc;
456
457 rtc->ops = ops;
458
459 err = __rtc_register_device(owner, rtc);
460 if (err)
461 return ERR_PTR(err);
462
463 return rtc;
464}
465EXPORT_SYMBOL_GPL(devm_rtc_device_register);
466
467static int __init rtc_init(void)
468{
469 rtc_class = class_create(THIS_MODULE, "rtc");
470 if (IS_ERR(rtc_class)) {
471 pr_err("couldn't create class\n");
472 return PTR_ERR(rtc_class);
473 }
474 rtc_class->pm = RTC_CLASS_DEV_PM_OPS;
475 rtc_dev_init();
476 return 0;
477}
478subsys_initcall(rtc_init);