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1/*
2 * RTC subsystem, dev interface
3 *
4 * Copyright (C) 2005 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 *
7 * based on arch/arm/common/rtctime.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/rtc.h>
18#include <linux/sched.h>
19#include "rtc-core.h"
20
21static dev_t rtc_devt;
22
23#define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */
24
25static int rtc_dev_open(struct inode *inode, struct file *file)
26{
27 int err;
28 struct rtc_device *rtc = container_of(inode->i_cdev,
29 struct rtc_device, char_dev);
30 const struct rtc_class_ops *ops = rtc->ops;
31
32 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
33 return -EBUSY;
34
35 file->private_data = rtc;
36
37 err = ops->open ? ops->open(rtc->dev.parent) : 0;
38 if (err == 0) {
39 spin_lock_irq(&rtc->irq_lock);
40 rtc->irq_data = 0;
41 spin_unlock_irq(&rtc->irq_lock);
42
43 return 0;
44 }
45
46 /* something has gone wrong */
47 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
48 return err;
49}
50
51#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
52/*
53 * Routine to poll RTC seconds field for change as often as possible,
54 * after first RTC_UIE use timer to reduce polling
55 */
56static void rtc_uie_task(struct work_struct *work)
57{
58 struct rtc_device *rtc =
59 container_of(work, struct rtc_device, uie_task);
60 struct rtc_time tm;
61 int num = 0;
62 int err;
63
64 err = rtc_read_time(rtc, &tm);
65
66 spin_lock_irq(&rtc->irq_lock);
67 if (rtc->stop_uie_polling || err) {
68 rtc->uie_task_active = 0;
69 } else if (rtc->oldsecs != tm.tm_sec) {
70 num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
71 rtc->oldsecs = tm.tm_sec;
72 rtc->uie_timer.expires = jiffies + HZ - (HZ/10);
73 rtc->uie_timer_active = 1;
74 rtc->uie_task_active = 0;
75 add_timer(&rtc->uie_timer);
76 } else if (schedule_work(&rtc->uie_task) == 0) {
77 rtc->uie_task_active = 0;
78 }
79 spin_unlock_irq(&rtc->irq_lock);
80 if (num)
81 rtc_handle_legacy_irq(rtc, num, RTC_UF);
82}
83static void rtc_uie_timer(unsigned long data)
84{
85 struct rtc_device *rtc = (struct rtc_device *)data;
86 unsigned long flags;
87
88 spin_lock_irqsave(&rtc->irq_lock, flags);
89 rtc->uie_timer_active = 0;
90 rtc->uie_task_active = 1;
91 if ((schedule_work(&rtc->uie_task) == 0))
92 rtc->uie_task_active = 0;
93 spin_unlock_irqrestore(&rtc->irq_lock, flags);
94}
95
96static int clear_uie(struct rtc_device *rtc)
97{
98 spin_lock_irq(&rtc->irq_lock);
99 if (rtc->uie_irq_active) {
100 rtc->stop_uie_polling = 1;
101 if (rtc->uie_timer_active) {
102 spin_unlock_irq(&rtc->irq_lock);
103 del_timer_sync(&rtc->uie_timer);
104 spin_lock_irq(&rtc->irq_lock);
105 rtc->uie_timer_active = 0;
106 }
107 if (rtc->uie_task_active) {
108 spin_unlock_irq(&rtc->irq_lock);
109 flush_scheduled_work();
110 spin_lock_irq(&rtc->irq_lock);
111 }
112 rtc->uie_irq_active = 0;
113 }
114 spin_unlock_irq(&rtc->irq_lock);
115 return 0;
116}
117
118static int set_uie(struct rtc_device *rtc)
119{
120 struct rtc_time tm;
121 int err;
122
123 err = rtc_read_time(rtc, &tm);
124 if (err)
125 return err;
126 spin_lock_irq(&rtc->irq_lock);
127 if (!rtc->uie_irq_active) {
128 rtc->uie_irq_active = 1;
129 rtc->stop_uie_polling = 0;
130 rtc->oldsecs = tm.tm_sec;
131 rtc->uie_task_active = 1;
132 if (schedule_work(&rtc->uie_task) == 0)
133 rtc->uie_task_active = 0;
134 }
135 rtc->irq_data = 0;
136 spin_unlock_irq(&rtc->irq_lock);
137 return 0;
138}
139
140int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled)
141{
142 if (enabled)
143 return set_uie(rtc);
144 else
145 return clear_uie(rtc);
146}
147EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul);
148
149#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
150
151static ssize_t
152rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
153{
154 struct rtc_device *rtc = file->private_data;
155
156 DECLARE_WAITQUEUE(wait, current);
157 unsigned long data;
158 ssize_t ret;
159
160 if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
161 return -EINVAL;
162
163 add_wait_queue(&rtc->irq_queue, &wait);
164 do {
165 __set_current_state(TASK_INTERRUPTIBLE);
166
167 spin_lock_irq(&rtc->irq_lock);
168 data = rtc->irq_data;
169 rtc->irq_data = 0;
170 spin_unlock_irq(&rtc->irq_lock);
171
172 if (data != 0) {
173 ret = 0;
174 break;
175 }
176 if (file->f_flags & O_NONBLOCK) {
177 ret = -EAGAIN;
178 break;
179 }
180 if (signal_pending(current)) {
181 ret = -ERESTARTSYS;
182 break;
183 }
184 schedule();
185 } while (1);
186 set_current_state(TASK_RUNNING);
187 remove_wait_queue(&rtc->irq_queue, &wait);
188
189 if (ret == 0) {
190 /* Check for any data updates */
191 if (rtc->ops->read_callback)
192 data = rtc->ops->read_callback(rtc->dev.parent,
193 data);
194
195 if (sizeof(int) != sizeof(long) &&
196 count == sizeof(unsigned int))
197 ret = put_user(data, (unsigned int __user *)buf) ?:
198 sizeof(unsigned int);
199 else
200 ret = put_user(data, (unsigned long __user *)buf) ?:
201 sizeof(unsigned long);
202 }
203 return ret;
204}
205
206static unsigned int rtc_dev_poll(struct file *file, poll_table *wait)
207{
208 struct rtc_device *rtc = file->private_data;
209 unsigned long data;
210
211 poll_wait(file, &rtc->irq_queue, wait);
212
213 data = rtc->irq_data;
214
215 return (data != 0) ? (POLLIN | POLLRDNORM) : 0;
216}
217
218static long rtc_dev_ioctl(struct file *file,
219 unsigned int cmd, unsigned long arg)
220{
221 int err = 0;
222 struct rtc_device *rtc = file->private_data;
223 const struct rtc_class_ops *ops = rtc->ops;
224 struct rtc_time tm;
225 struct rtc_wkalrm alarm;
226 void __user *uarg = (void __user *) arg;
227
228 err = mutex_lock_interruptible(&rtc->ops_lock);
229 if (err)
230 return err;
231
232 /* check that the calling task has appropriate permissions
233 * for certain ioctls. doing this check here is useful
234 * to avoid duplicate code in each driver.
235 */
236 switch (cmd) {
237 case RTC_EPOCH_SET:
238 case RTC_SET_TIME:
239 if (!capable(CAP_SYS_TIME))
240 err = -EACCES;
241 break;
242
243 case RTC_IRQP_SET:
244 if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
245 err = -EACCES;
246 break;
247
248 case RTC_PIE_ON:
249 if (rtc->irq_freq > rtc->max_user_freq &&
250 !capable(CAP_SYS_RESOURCE))
251 err = -EACCES;
252 break;
253 }
254
255 if (err)
256 goto done;
257
258 /*
259 * Drivers *SHOULD NOT* provide ioctl implementations
260 * for these requests. Instead, provide methods to
261 * support the following code, so that the RTC's main
262 * features are accessible without using ioctls.
263 *
264 * RTC and alarm times will be in UTC, by preference,
265 * but dual-booting with MS-Windows implies RTCs must
266 * use the local wall clock time.
267 */
268
269 switch (cmd) {
270 case RTC_ALM_READ:
271 mutex_unlock(&rtc->ops_lock);
272
273 err = rtc_read_alarm(rtc, &alarm);
274 if (err < 0)
275 return err;
276
277 if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
278 err = -EFAULT;
279 return err;
280
281 case RTC_ALM_SET:
282 mutex_unlock(&rtc->ops_lock);
283
284 if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
285 return -EFAULT;
286
287 alarm.enabled = 0;
288 alarm.pending = 0;
289 alarm.time.tm_wday = -1;
290 alarm.time.tm_yday = -1;
291 alarm.time.tm_isdst = -1;
292
293 /* RTC_ALM_SET alarms may be up to 24 hours in the future.
294 * Rather than expecting every RTC to implement "don't care"
295 * for day/month/year fields, just force the alarm to have
296 * the right values for those fields.
297 *
298 * RTC_WKALM_SET should be used instead. Not only does it
299 * eliminate the need for a separate RTC_AIE_ON call, it
300 * doesn't have the "alarm 23:59:59 in the future" race.
301 *
302 * NOTE: some legacy code may have used invalid fields as
303 * wildcards, exposing hardware "periodic alarm" capabilities.
304 * Not supported here.
305 */
306 {
307 time64_t now, then;
308
309 err = rtc_read_time(rtc, &tm);
310 if (err < 0)
311 return err;
312 now = rtc_tm_to_time64(&tm);
313
314 alarm.time.tm_mday = tm.tm_mday;
315 alarm.time.tm_mon = tm.tm_mon;
316 alarm.time.tm_year = tm.tm_year;
317 err = rtc_valid_tm(&alarm.time);
318 if (err < 0)
319 return err;
320 then = rtc_tm_to_time64(&alarm.time);
321
322 /* alarm may need to wrap into tomorrow */
323 if (then < now) {
324 rtc_time64_to_tm(now + 24 * 60 * 60, &tm);
325 alarm.time.tm_mday = tm.tm_mday;
326 alarm.time.tm_mon = tm.tm_mon;
327 alarm.time.tm_year = tm.tm_year;
328 }
329 }
330
331 return rtc_set_alarm(rtc, &alarm);
332
333 case RTC_RD_TIME:
334 mutex_unlock(&rtc->ops_lock);
335
336 err = rtc_read_time(rtc, &tm);
337 if (err < 0)
338 return err;
339
340 if (copy_to_user(uarg, &tm, sizeof(tm)))
341 err = -EFAULT;
342 return err;
343
344 case RTC_SET_TIME:
345 mutex_unlock(&rtc->ops_lock);
346
347 if (copy_from_user(&tm, uarg, sizeof(tm)))
348 return -EFAULT;
349
350 return rtc_set_time(rtc, &tm);
351
352 case RTC_PIE_ON:
353 err = rtc_irq_set_state(rtc, NULL, 1);
354 break;
355
356 case RTC_PIE_OFF:
357 err = rtc_irq_set_state(rtc, NULL, 0);
358 break;
359
360 case RTC_AIE_ON:
361 mutex_unlock(&rtc->ops_lock);
362 return rtc_alarm_irq_enable(rtc, 1);
363
364 case RTC_AIE_OFF:
365 mutex_unlock(&rtc->ops_lock);
366 return rtc_alarm_irq_enable(rtc, 0);
367
368 case RTC_UIE_ON:
369 mutex_unlock(&rtc->ops_lock);
370 return rtc_update_irq_enable(rtc, 1);
371
372 case RTC_UIE_OFF:
373 mutex_unlock(&rtc->ops_lock);
374 return rtc_update_irq_enable(rtc, 0);
375
376 case RTC_IRQP_SET:
377 err = rtc_irq_set_freq(rtc, NULL, arg);
378 break;
379
380 case RTC_IRQP_READ:
381 err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
382 break;
383
384 case RTC_WKALM_SET:
385 mutex_unlock(&rtc->ops_lock);
386 if (copy_from_user(&alarm, uarg, sizeof(alarm)))
387 return -EFAULT;
388
389 return rtc_set_alarm(rtc, &alarm);
390
391 case RTC_WKALM_RD:
392 mutex_unlock(&rtc->ops_lock);
393 err = rtc_read_alarm(rtc, &alarm);
394 if (err < 0)
395 return err;
396
397 if (copy_to_user(uarg, &alarm, sizeof(alarm)))
398 err = -EFAULT;
399 return err;
400
401 default:
402 /* Finally try the driver's ioctl interface */
403 if (ops->ioctl) {
404 err = ops->ioctl(rtc->dev.parent, cmd, arg);
405 if (err == -ENOIOCTLCMD)
406 err = -ENOTTY;
407 } else
408 err = -ENOTTY;
409 break;
410 }
411
412done:
413 mutex_unlock(&rtc->ops_lock);
414 return err;
415}
416
417static int rtc_dev_fasync(int fd, struct file *file, int on)
418{
419 struct rtc_device *rtc = file->private_data;
420 return fasync_helper(fd, file, on, &rtc->async_queue);
421}
422
423static int rtc_dev_release(struct inode *inode, struct file *file)
424{
425 struct rtc_device *rtc = file->private_data;
426
427 /* We shut down the repeating IRQs that userspace enabled,
428 * since nothing is listening to them.
429 * - Update (UIE) ... currently only managed through ioctls
430 * - Periodic (PIE) ... also used through rtc_*() interface calls
431 *
432 * Leave the alarm alone; it may be set to trigger a system wakeup
433 * later, or be used by kernel code, and is a one-shot event anyway.
434 */
435
436 /* Keep ioctl until all drivers are converted */
437 rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
438 rtc_update_irq_enable(rtc, 0);
439 rtc_irq_set_state(rtc, NULL, 0);
440
441 if (rtc->ops->release)
442 rtc->ops->release(rtc->dev.parent);
443
444 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
445 return 0;
446}
447
448static const struct file_operations rtc_dev_fops = {
449 .owner = THIS_MODULE,
450 .llseek = no_llseek,
451 .read = rtc_dev_read,
452 .poll = rtc_dev_poll,
453 .unlocked_ioctl = rtc_dev_ioctl,
454 .open = rtc_dev_open,
455 .release = rtc_dev_release,
456 .fasync = rtc_dev_fasync,
457};
458
459/* insertion/removal hooks */
460
461void rtc_dev_prepare(struct rtc_device *rtc)
462{
463 if (!rtc_devt)
464 return;
465
466 if (rtc->id >= RTC_DEV_MAX) {
467 dev_dbg(&rtc->dev, "%s: too many RTC devices\n", rtc->name);
468 return;
469 }
470
471 rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
472
473#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
474 INIT_WORK(&rtc->uie_task, rtc_uie_task);
475 setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);
476#endif
477
478 cdev_init(&rtc->char_dev, &rtc_dev_fops);
479 rtc->char_dev.owner = rtc->owner;
480 rtc->char_dev.kobj.parent = &rtc->dev.kobj;
481}
482
483void rtc_dev_add_device(struct rtc_device *rtc)
484{
485 if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1))
486 dev_warn(&rtc->dev, "%s: failed to add char device %d:%d\n",
487 rtc->name, MAJOR(rtc_devt), rtc->id);
488 else
489 dev_dbg(&rtc->dev, "%s: dev (%d:%d)\n", rtc->name,
490 MAJOR(rtc_devt), rtc->id);
491}
492
493void rtc_dev_del_device(struct rtc_device *rtc)
494{
495 if (rtc->dev.devt)
496 cdev_del(&rtc->char_dev);
497}
498
499void __init rtc_dev_init(void)
500{
501 int err;
502
503 err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
504 if (err < 0)
505 pr_err("failed to allocate char dev region\n");
506}
507
508void __exit rtc_dev_exit(void)
509{
510 if (rtc_devt)
511 unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
512}
1/*
2 * RTC subsystem, dev interface
3 *
4 * Copyright (C) 2005 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 *
7 * based on arch/arm/common/rtctime.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/rtc.h>
18#include <linux/sched/signal.h>
19#include "rtc-core.h"
20
21static dev_t rtc_devt;
22
23#define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */
24
25static int rtc_dev_open(struct inode *inode, struct file *file)
26{
27 struct rtc_device *rtc = container_of(inode->i_cdev,
28 struct rtc_device, char_dev);
29
30 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
31 return -EBUSY;
32
33 file->private_data = rtc;
34
35 spin_lock_irq(&rtc->irq_lock);
36 rtc->irq_data = 0;
37 spin_unlock_irq(&rtc->irq_lock);
38
39 return 0;
40}
41
42#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
43/*
44 * Routine to poll RTC seconds field for change as often as possible,
45 * after first RTC_UIE use timer to reduce polling
46 */
47static void rtc_uie_task(struct work_struct *work)
48{
49 struct rtc_device *rtc =
50 container_of(work, struct rtc_device, uie_task);
51 struct rtc_time tm;
52 int num = 0;
53 int err;
54
55 err = rtc_read_time(rtc, &tm);
56
57 spin_lock_irq(&rtc->irq_lock);
58 if (rtc->stop_uie_polling || err) {
59 rtc->uie_task_active = 0;
60 } else if (rtc->oldsecs != tm.tm_sec) {
61 num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
62 rtc->oldsecs = tm.tm_sec;
63 rtc->uie_timer.expires = jiffies + HZ - (HZ/10);
64 rtc->uie_timer_active = 1;
65 rtc->uie_task_active = 0;
66 add_timer(&rtc->uie_timer);
67 } else if (schedule_work(&rtc->uie_task) == 0) {
68 rtc->uie_task_active = 0;
69 }
70 spin_unlock_irq(&rtc->irq_lock);
71 if (num)
72 rtc_handle_legacy_irq(rtc, num, RTC_UF);
73}
74static void rtc_uie_timer(struct timer_list *t)
75{
76 struct rtc_device *rtc = from_timer(rtc, t, uie_timer);
77 unsigned long flags;
78
79 spin_lock_irqsave(&rtc->irq_lock, flags);
80 rtc->uie_timer_active = 0;
81 rtc->uie_task_active = 1;
82 if ((schedule_work(&rtc->uie_task) == 0))
83 rtc->uie_task_active = 0;
84 spin_unlock_irqrestore(&rtc->irq_lock, flags);
85}
86
87static int clear_uie(struct rtc_device *rtc)
88{
89 spin_lock_irq(&rtc->irq_lock);
90 if (rtc->uie_irq_active) {
91 rtc->stop_uie_polling = 1;
92 if (rtc->uie_timer_active) {
93 spin_unlock_irq(&rtc->irq_lock);
94 del_timer_sync(&rtc->uie_timer);
95 spin_lock_irq(&rtc->irq_lock);
96 rtc->uie_timer_active = 0;
97 }
98 if (rtc->uie_task_active) {
99 spin_unlock_irq(&rtc->irq_lock);
100 flush_scheduled_work();
101 spin_lock_irq(&rtc->irq_lock);
102 }
103 rtc->uie_irq_active = 0;
104 }
105 spin_unlock_irq(&rtc->irq_lock);
106 return 0;
107}
108
109static int set_uie(struct rtc_device *rtc)
110{
111 struct rtc_time tm;
112 int err;
113
114 err = rtc_read_time(rtc, &tm);
115 if (err)
116 return err;
117 spin_lock_irq(&rtc->irq_lock);
118 if (!rtc->uie_irq_active) {
119 rtc->uie_irq_active = 1;
120 rtc->stop_uie_polling = 0;
121 rtc->oldsecs = tm.tm_sec;
122 rtc->uie_task_active = 1;
123 if (schedule_work(&rtc->uie_task) == 0)
124 rtc->uie_task_active = 0;
125 }
126 rtc->irq_data = 0;
127 spin_unlock_irq(&rtc->irq_lock);
128 return 0;
129}
130
131int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled)
132{
133 if (enabled)
134 return set_uie(rtc);
135 else
136 return clear_uie(rtc);
137}
138EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul);
139
140#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
141
142static ssize_t
143rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
144{
145 struct rtc_device *rtc = file->private_data;
146
147 DECLARE_WAITQUEUE(wait, current);
148 unsigned long data;
149 ssize_t ret;
150
151 if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
152 return -EINVAL;
153
154 add_wait_queue(&rtc->irq_queue, &wait);
155 do {
156 __set_current_state(TASK_INTERRUPTIBLE);
157
158 spin_lock_irq(&rtc->irq_lock);
159 data = rtc->irq_data;
160 rtc->irq_data = 0;
161 spin_unlock_irq(&rtc->irq_lock);
162
163 if (data != 0) {
164 ret = 0;
165 break;
166 }
167 if (file->f_flags & O_NONBLOCK) {
168 ret = -EAGAIN;
169 break;
170 }
171 if (signal_pending(current)) {
172 ret = -ERESTARTSYS;
173 break;
174 }
175 schedule();
176 } while (1);
177 set_current_state(TASK_RUNNING);
178 remove_wait_queue(&rtc->irq_queue, &wait);
179
180 if (ret == 0) {
181 /* Check for any data updates */
182 if (rtc->ops->read_callback)
183 data = rtc->ops->read_callback(rtc->dev.parent,
184 data);
185
186 if (sizeof(int) != sizeof(long) &&
187 count == sizeof(unsigned int))
188 ret = put_user(data, (unsigned int __user *)buf) ?:
189 sizeof(unsigned int);
190 else
191 ret = put_user(data, (unsigned long __user *)buf) ?:
192 sizeof(unsigned long);
193 }
194 return ret;
195}
196
197static __poll_t rtc_dev_poll(struct file *file, poll_table *wait)
198{
199 struct rtc_device *rtc = file->private_data;
200 unsigned long data;
201
202 poll_wait(file, &rtc->irq_queue, wait);
203
204 data = rtc->irq_data;
205
206 return (data != 0) ? (EPOLLIN | EPOLLRDNORM) : 0;
207}
208
209static long rtc_dev_ioctl(struct file *file,
210 unsigned int cmd, unsigned long arg)
211{
212 int err = 0;
213 struct rtc_device *rtc = file->private_data;
214 const struct rtc_class_ops *ops = rtc->ops;
215 struct rtc_time tm;
216 struct rtc_wkalrm alarm;
217 void __user *uarg = (void __user *) arg;
218
219 err = mutex_lock_interruptible(&rtc->ops_lock);
220 if (err)
221 return err;
222
223 /* check that the calling task has appropriate permissions
224 * for certain ioctls. doing this check here is useful
225 * to avoid duplicate code in each driver.
226 */
227 switch (cmd) {
228 case RTC_EPOCH_SET:
229 case RTC_SET_TIME:
230 if (!capable(CAP_SYS_TIME))
231 err = -EACCES;
232 break;
233
234 case RTC_IRQP_SET:
235 if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
236 err = -EACCES;
237 break;
238
239 case RTC_PIE_ON:
240 if (rtc->irq_freq > rtc->max_user_freq &&
241 !capable(CAP_SYS_RESOURCE))
242 err = -EACCES;
243 break;
244 }
245
246 if (err)
247 goto done;
248
249 /*
250 * Drivers *SHOULD NOT* provide ioctl implementations
251 * for these requests. Instead, provide methods to
252 * support the following code, so that the RTC's main
253 * features are accessible without using ioctls.
254 *
255 * RTC and alarm times will be in UTC, by preference,
256 * but dual-booting with MS-Windows implies RTCs must
257 * use the local wall clock time.
258 */
259
260 switch (cmd) {
261 case RTC_ALM_READ:
262 mutex_unlock(&rtc->ops_lock);
263
264 err = rtc_read_alarm(rtc, &alarm);
265 if (err < 0)
266 return err;
267
268 if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
269 err = -EFAULT;
270 return err;
271
272 case RTC_ALM_SET:
273 mutex_unlock(&rtc->ops_lock);
274
275 if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
276 return -EFAULT;
277
278 alarm.enabled = 0;
279 alarm.pending = 0;
280 alarm.time.tm_wday = -1;
281 alarm.time.tm_yday = -1;
282 alarm.time.tm_isdst = -1;
283
284 /* RTC_ALM_SET alarms may be up to 24 hours in the future.
285 * Rather than expecting every RTC to implement "don't care"
286 * for day/month/year fields, just force the alarm to have
287 * the right values for those fields.
288 *
289 * RTC_WKALM_SET should be used instead. Not only does it
290 * eliminate the need for a separate RTC_AIE_ON call, it
291 * doesn't have the "alarm 23:59:59 in the future" race.
292 *
293 * NOTE: some legacy code may have used invalid fields as
294 * wildcards, exposing hardware "periodic alarm" capabilities.
295 * Not supported here.
296 */
297 {
298 time64_t now, then;
299
300 err = rtc_read_time(rtc, &tm);
301 if (err < 0)
302 return err;
303 now = rtc_tm_to_time64(&tm);
304
305 alarm.time.tm_mday = tm.tm_mday;
306 alarm.time.tm_mon = tm.tm_mon;
307 alarm.time.tm_year = tm.tm_year;
308 err = rtc_valid_tm(&alarm.time);
309 if (err < 0)
310 return err;
311 then = rtc_tm_to_time64(&alarm.time);
312
313 /* alarm may need to wrap into tomorrow */
314 if (then < now) {
315 rtc_time64_to_tm(now + 24 * 60 * 60, &tm);
316 alarm.time.tm_mday = tm.tm_mday;
317 alarm.time.tm_mon = tm.tm_mon;
318 alarm.time.tm_year = tm.tm_year;
319 }
320 }
321
322 return rtc_set_alarm(rtc, &alarm);
323
324 case RTC_RD_TIME:
325 mutex_unlock(&rtc->ops_lock);
326
327 err = rtc_read_time(rtc, &tm);
328 if (err < 0)
329 return err;
330
331 if (copy_to_user(uarg, &tm, sizeof(tm)))
332 err = -EFAULT;
333 return err;
334
335 case RTC_SET_TIME:
336 mutex_unlock(&rtc->ops_lock);
337
338 if (copy_from_user(&tm, uarg, sizeof(tm)))
339 return -EFAULT;
340
341 return rtc_set_time(rtc, &tm);
342
343 case RTC_PIE_ON:
344 err = rtc_irq_set_state(rtc, NULL, 1);
345 break;
346
347 case RTC_PIE_OFF:
348 err = rtc_irq_set_state(rtc, NULL, 0);
349 break;
350
351 case RTC_AIE_ON:
352 mutex_unlock(&rtc->ops_lock);
353 return rtc_alarm_irq_enable(rtc, 1);
354
355 case RTC_AIE_OFF:
356 mutex_unlock(&rtc->ops_lock);
357 return rtc_alarm_irq_enable(rtc, 0);
358
359 case RTC_UIE_ON:
360 mutex_unlock(&rtc->ops_lock);
361 return rtc_update_irq_enable(rtc, 1);
362
363 case RTC_UIE_OFF:
364 mutex_unlock(&rtc->ops_lock);
365 return rtc_update_irq_enable(rtc, 0);
366
367 case RTC_IRQP_SET:
368 err = rtc_irq_set_freq(rtc, NULL, arg);
369 break;
370
371 case RTC_IRQP_READ:
372 err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
373 break;
374
375 case RTC_WKALM_SET:
376 mutex_unlock(&rtc->ops_lock);
377 if (copy_from_user(&alarm, uarg, sizeof(alarm)))
378 return -EFAULT;
379
380 return rtc_set_alarm(rtc, &alarm);
381
382 case RTC_WKALM_RD:
383 mutex_unlock(&rtc->ops_lock);
384 err = rtc_read_alarm(rtc, &alarm);
385 if (err < 0)
386 return err;
387
388 if (copy_to_user(uarg, &alarm, sizeof(alarm)))
389 err = -EFAULT;
390 return err;
391
392 default:
393 /* Finally try the driver's ioctl interface */
394 if (ops->ioctl) {
395 err = ops->ioctl(rtc->dev.parent, cmd, arg);
396 if (err == -ENOIOCTLCMD)
397 err = -ENOTTY;
398 } else
399 err = -ENOTTY;
400 break;
401 }
402
403done:
404 mutex_unlock(&rtc->ops_lock);
405 return err;
406}
407
408static int rtc_dev_fasync(int fd, struct file *file, int on)
409{
410 struct rtc_device *rtc = file->private_data;
411 return fasync_helper(fd, file, on, &rtc->async_queue);
412}
413
414static int rtc_dev_release(struct inode *inode, struct file *file)
415{
416 struct rtc_device *rtc = file->private_data;
417
418 /* We shut down the repeating IRQs that userspace enabled,
419 * since nothing is listening to them.
420 * - Update (UIE) ... currently only managed through ioctls
421 * - Periodic (PIE) ... also used through rtc_*() interface calls
422 *
423 * Leave the alarm alone; it may be set to trigger a system wakeup
424 * later, or be used by kernel code, and is a one-shot event anyway.
425 */
426
427 /* Keep ioctl until all drivers are converted */
428 rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
429 rtc_update_irq_enable(rtc, 0);
430 rtc_irq_set_state(rtc, NULL, 0);
431
432 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
433 return 0;
434}
435
436static const struct file_operations rtc_dev_fops = {
437 .owner = THIS_MODULE,
438 .llseek = no_llseek,
439 .read = rtc_dev_read,
440 .poll = rtc_dev_poll,
441 .unlocked_ioctl = rtc_dev_ioctl,
442 .open = rtc_dev_open,
443 .release = rtc_dev_release,
444 .fasync = rtc_dev_fasync,
445};
446
447/* insertion/removal hooks */
448
449void rtc_dev_prepare(struct rtc_device *rtc)
450{
451 if (!rtc_devt)
452 return;
453
454 if (rtc->id >= RTC_DEV_MAX) {
455 dev_dbg(&rtc->dev, "too many RTC devices\n");
456 return;
457 }
458
459 rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
460
461#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
462 INIT_WORK(&rtc->uie_task, rtc_uie_task);
463 timer_setup(&rtc->uie_timer, rtc_uie_timer, 0);
464#endif
465
466 cdev_init(&rtc->char_dev, &rtc_dev_fops);
467 rtc->char_dev.owner = rtc->owner;
468}
469
470void __init rtc_dev_init(void)
471{
472 int err;
473
474 err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
475 if (err < 0)
476 pr_err("failed to allocate char dev region\n");
477}
478
479void __exit rtc_dev_exit(void)
480{
481 if (rtc_devt)
482 unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
483}