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Hibernation: Add PM_RESTORE_PREPARE and PM_POST_RESTORE notifiers (rev. 2)
[linux-2.6/linux-2.6-openrd.git] / drivers / rtc / rtc-dev.c
blob025c60a17a4a3c9841d4105bf0344a92f9c31510
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 #include <linux/module.h>
15 #include <linux/rtc.h>
16 #include "rtc-core.h"
17
18 static dev_t rtc_devt;
19
20 #define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */
21
22 static int rtc_dev_open(struct inode *inode, struct file *file)
23 {
24 int err;
25 struct rtc_device *rtc = container_of(inode->i_cdev,
26 struct rtc_device, char_dev);
27 const struct rtc_class_ops *ops = rtc->ops;
28
29 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
30 return -EBUSY;
31
32 file->private_data = rtc;
33
34 err = ops->open ? ops->open(rtc->dev.parent) : 0;
35 if (err == 0) {
36 spin_lock_irq(&rtc->irq_lock);
37 rtc->irq_data = 0;
38 spin_unlock_irq(&rtc->irq_lock);
39
40 return 0;
41 }
42
43 /* something has gone wrong */
44 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
45 return err;
46 }
47
48 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
49 /*
50 * Routine to poll RTC seconds field for change as often as possible,
51 * after first RTC_UIE use timer to reduce polling
52 */
53 static void rtc_uie_task(struct work_struct *work)
54 {
55 struct rtc_device *rtc =
56 container_of(work, struct rtc_device, uie_task);
57 struct rtc_time tm;
58 int num = 0;
59 int err;
60
61 err = rtc_read_time(rtc, &tm);
62
63 local_irq_disable();
64 spin_lock(&rtc->irq_lock);
65 if (rtc->stop_uie_polling || err) {
66 rtc->uie_task_active = 0;
67 } else if (rtc->oldsecs != tm.tm_sec) {
68 num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
69 rtc->oldsecs = tm.tm_sec;
70 rtc->uie_timer.expires = jiffies + HZ - (HZ/10);
71 rtc->uie_timer_active = 1;
72 rtc->uie_task_active = 0;
73 add_timer(&rtc->uie_timer);
74 } else if (schedule_work(&rtc->uie_task) == 0) {
75 rtc->uie_task_active = 0;
76 }
77 spin_unlock(&rtc->irq_lock);
78 if (num)
79 rtc_update_irq(rtc, num, RTC_UF | RTC_IRQF);
80 local_irq_enable();
81 }
82 static void rtc_uie_timer(unsigned long data)
83 {
84 struct rtc_device *rtc = (struct rtc_device *)data;
85 unsigned long flags;
86
87 spin_lock_irqsave(&rtc->irq_lock, flags);
88 rtc->uie_timer_active = 0;
89 rtc->uie_task_active = 1;
90 if ((schedule_work(&rtc->uie_task) == 0))
91 rtc->uie_task_active = 0;
92 spin_unlock_irqrestore(&rtc->irq_lock, flags);
93 }
94
95 static void clear_uie(struct rtc_device *rtc)
96 {
97 spin_lock_irq(&rtc->irq_lock);
98 if (rtc->irq_active) {
99 rtc->stop_uie_polling = 1;
100 if (rtc->uie_timer_active) {
101 spin_unlock_irq(&rtc->irq_lock);
102 del_timer_sync(&rtc->uie_timer);
103 spin_lock_irq(&rtc->irq_lock);
104 rtc->uie_timer_active = 0;
105 }
106 if (rtc->uie_task_active) {
107 spin_unlock_irq(&rtc->irq_lock);
108 flush_scheduled_work();
109 spin_lock_irq(&rtc->irq_lock);
110 }
111 rtc->irq_active = 0;
112 }
113 spin_unlock_irq(&rtc->irq_lock);
114 }
115
116 static int set_uie(struct rtc_device *rtc)
117 {
118 struct rtc_time tm;
119 int err;
120
121 err = rtc_read_time(rtc, &tm);
122 if (err)
123 return err;
124 spin_lock_irq(&rtc->irq_lock);
125 if (!rtc->irq_active) {
126 rtc->irq_active = 1;
127 rtc->stop_uie_polling = 0;
128 rtc->oldsecs = tm.tm_sec;
129 rtc->uie_task_active = 1;
130 if (schedule_work(&rtc->uie_task) == 0)
131 rtc->uie_task_active = 0;
132 }
133 rtc->irq_data = 0;
134 spin_unlock_irq(&rtc->irq_lock);
135 return 0;
136 }
137 #endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
138
139 static ssize_t
140 rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
141 {
142 struct rtc_device *rtc = file->private_data;
143
144 DECLARE_WAITQUEUE(wait, current);
145 unsigned long data;
146 ssize_t ret;
147
148 if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
149 return -EINVAL;
150
151 add_wait_queue(&rtc->irq_queue, &wait);
152 do {
153 __set_current_state(TASK_INTERRUPTIBLE);
154
155 spin_lock_irq(&rtc->irq_lock);
156 data = rtc->irq_data;
157 rtc->irq_data = 0;
158 spin_unlock_irq(&rtc->irq_lock);
159
160 if (data != 0) {
161 ret = 0;
162 break;
163 }
164 if (file->f_flags & O_NONBLOCK) {
165 ret = -EAGAIN;
166 break;
167 }
168 if (signal_pending(current)) {
169 ret = -ERESTARTSYS;
170 break;
171 }
172 schedule();
173 } while (1);
174 set_current_state(TASK_RUNNING);
175 remove_wait_queue(&rtc->irq_queue, &wait);
176
177 if (ret == 0) {
178 /* Check for any data updates */
179 if (rtc->ops->read_callback)
180 data = rtc->ops->read_callback(rtc->dev.parent,
181 data);
182
183 if (sizeof(int) != sizeof(long) &&
184 count == sizeof(unsigned int))
185 ret = put_user(data, (unsigned int __user *)buf) ?:
186 sizeof(unsigned int);
187 else
188 ret = put_user(data, (unsigned long __user *)buf) ?:
189 sizeof(unsigned long);
190 }
191 return ret;
192 }
193
194 static unsigned int rtc_dev_poll(struct file *file, poll_table *wait)
195 {
196 struct rtc_device *rtc = file->private_data;
197 unsigned long data;
198
199 poll_wait(file, &rtc->irq_queue, wait);
200
201 data = rtc->irq_data;
202
203 return (data != 0) ? (POLLIN | POLLRDNORM) : 0;
204 }
205
206 static int rtc_dev_ioctl(struct inode *inode, struct file *file,
207 unsigned int cmd, unsigned long arg)
208 {
209 int err = 0;
210 struct rtc_device *rtc = file->private_data;
211 const struct rtc_class_ops *ops = rtc->ops;
212 struct rtc_time tm;
213 struct rtc_wkalrm alarm;
214 void __user *uarg = (void __user *) arg;
215
216 /* check that the calling task has appropriate permissions
217 * for certain ioctls. doing this check here is useful
218 * to avoid duplicate code in each driver.
219 */
220 switch (cmd) {
221 case RTC_EPOCH_SET:
222 case RTC_SET_TIME:
223 if (!capable(CAP_SYS_TIME))
224 return -EACCES;
225 break;
226
227 case RTC_IRQP_SET:
228 if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
229 return -EACCES;
230 break;
231
232 case RTC_PIE_ON:
233 if (rtc->irq_freq > rtc->max_user_freq &&
234 !capable(CAP_SYS_RESOURCE))
235 return -EACCES;
236 break;
237 }
238
239 /* try the driver's ioctl interface */
240 if (ops->ioctl) {
241 err = ops->ioctl(rtc->dev.parent, cmd, arg);
242 if (err != -ENOIOCTLCMD)
243 return err;
244 }
245
246 /* if the driver does not provide the ioctl interface
247 * or if that particular ioctl was not implemented
248 * (-ENOIOCTLCMD), we will try to emulate here.
249 */
250
251 switch (cmd) {
252 case RTC_ALM_READ:
253 err = rtc_read_alarm(rtc, &alarm);
254 if (err < 0)
255 return err;
256
257 if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
258 return -EFAULT;
259 break;
260
261 case RTC_ALM_SET:
262 if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
263 return -EFAULT;
264
265 alarm.enabled = 0;
266 alarm.pending = 0;
267 alarm.time.tm_wday = -1;
268 alarm.time.tm_yday = -1;
269 alarm.time.tm_isdst = -1;
270
271 /* RTC_ALM_SET alarms may be up to 24 hours in the future.
272 * Rather than expecting every RTC to implement "don't care"
273 * for day/month/year fields, just force the alarm to have
274 * the right values for those fields.
275 *
276 * RTC_WKALM_SET should be used instead. Not only does it
277 * eliminate the need for a separate RTC_AIE_ON call, it
278 * doesn't have the "alarm 23:59:59 in the future" race.
279 *
280 * NOTE: some legacy code may have used invalid fields as
281 * wildcards, exposing hardware "periodic alarm" capabilities.
282 * Not supported here.
283 */
284 {
285 unsigned long now, then;
286
287 err = rtc_read_time(rtc, &tm);
288 if (err < 0)
289 return err;
290 rtc_tm_to_time(&tm, &now);
291
292 alarm.time.tm_mday = tm.tm_mday;
293 alarm.time.tm_mon = tm.tm_mon;
294 alarm.time.tm_year = tm.tm_year;
295 err = rtc_valid_tm(&alarm.time);
296 if (err < 0)
297 return err;
298 rtc_tm_to_time(&alarm.time, &then);
299
300 /* alarm may need to wrap into tomorrow */
301 if (then < now) {
302 rtc_time_to_tm(now + 24 * 60 * 60, &tm);
303 alarm.time.tm_mday = tm.tm_mday;
304 alarm.time.tm_mon = tm.tm_mon;
305 alarm.time.tm_year = tm.tm_year;
306 }
307 }
308
309 err = rtc_set_alarm(rtc, &alarm);
310 break;
311
312 case RTC_RD_TIME:
313 err = rtc_read_time(rtc, &tm);
314 if (err < 0)
315 return err;
316
317 if (copy_to_user(uarg, &tm, sizeof(tm)))
318 return -EFAULT;
319 break;
320
321 case RTC_SET_TIME:
322 if (copy_from_user(&tm, uarg, sizeof(tm)))
323 return -EFAULT;
324
325 err = rtc_set_time(rtc, &tm);
326 break;
327
328 case RTC_PIE_ON:
329 err = rtc_irq_set_state(rtc, NULL, 1);
330 break;
331
332 case RTC_PIE_OFF:
333 err = rtc_irq_set_state(rtc, NULL, 0);
334 break;
335
336 case RTC_IRQP_SET:
337 err = rtc_irq_set_freq(rtc, NULL, arg);
338 break;
339
340 case RTC_IRQP_READ:
341 err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
342 break;
343
344 #if 0
345 case RTC_EPOCH_SET:
346 #ifndef rtc_epoch
347 /*
348 * There were no RTC clocks before 1900.
349 */
350 if (arg < 1900) {
351 err = -EINVAL;
352 break;
353 }
354 rtc_epoch = arg;
355 err = 0;
356 #endif
357 break;
358
359 case RTC_EPOCH_READ:
360 err = put_user(rtc_epoch, (unsigned long __user *)uarg);
361 break;
362 #endif
363 case RTC_WKALM_SET:
364 if (copy_from_user(&alarm, uarg, sizeof(alarm)))
365 return -EFAULT;
366
367 err = rtc_set_alarm(rtc, &alarm);
368 break;
369
370 case RTC_WKALM_RD:
371 err = rtc_read_alarm(rtc, &alarm);
372 if (err < 0)
373 return err;
374
375 if (copy_to_user(uarg, &alarm, sizeof(alarm)))
376 return -EFAULT;
377 break;
378
379 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
380 case RTC_UIE_OFF:
381 clear_uie(rtc);
382 return 0;
383
384 case RTC_UIE_ON:
385 return set_uie(rtc);
386 #endif
387 default:
388 err = -ENOTTY;
389 break;
390 }
391
392 return err;
393 }
394
395 static int rtc_dev_release(struct inode *inode, struct file *file)
396 {
397 struct rtc_device *rtc = file->private_data;
398
399 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
400 clear_uie(rtc);
401 #endif
402 if (rtc->ops->release)
403 rtc->ops->release(rtc->dev.parent);
404
405 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
406 return 0;
407 }
408
409 static int rtc_dev_fasync(int fd, struct file *file, int on)
410 {
411 struct rtc_device *rtc = file->private_data;
412 return fasync_helper(fd, file, on, &rtc->async_queue);
413 }
414
415 static const struct file_operations rtc_dev_fops = {
416 .owner = THIS_MODULE,
417 .llseek = no_llseek,
418 .read = rtc_dev_read,
419 .poll = rtc_dev_poll,
420 .ioctl = rtc_dev_ioctl,
421 .open = rtc_dev_open,
422 .release = rtc_dev_release,
423 .fasync = rtc_dev_fasync,
424 };
425
426 /* insertion/removal hooks */
427
428 void rtc_dev_prepare(struct rtc_device *rtc)
429 {
430 if (!rtc_devt)
431 return;
432
433 if (rtc->id >= RTC_DEV_MAX) {
434 pr_debug("%s: too many RTC devices\n", rtc->name);
435 return;
436 }
437
438 rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
439
440 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
441 INIT_WORK(&rtc->uie_task, rtc_uie_task);
442 setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);
443 #endif
444
445 cdev_init(&rtc->char_dev, &rtc_dev_fops);
446 rtc->char_dev.owner = rtc->owner;
447 }
448
449 void rtc_dev_add_device(struct rtc_device *rtc)
450 {
451 if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1))
452 printk(KERN_WARNING "%s: failed to add char device %d:%d\n",
453 rtc->name, MAJOR(rtc_devt), rtc->id);
454 else
455 pr_debug("%s: dev (%d:%d)\n", rtc->name,
456 MAJOR(rtc_devt), rtc->id);
457 }
458
459 void rtc_dev_del_device(struct rtc_device *rtc)
460 {
461 if (rtc->dev.devt)
462 cdev_del(&rtc->char_dev);
463 }
464
465 void __init rtc_dev_init(void)
466 {
467 int err;
468
469 err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
470 if (err < 0)
471 printk(KERN_ERR "%s: failed to allocate char dev region\n",
472 __FILE__);
473 }
474
475 void __exit rtc_dev_exit(void)
476 {
477 if (rtc_devt)
478 unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
479 }
linux 2.6 git repository for openrd