Commit | Line | Data |
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e824290e AZ |
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> | |
d43c36dc | 16 | #include <linux/sched.h> |
5726fb20 | 17 | #include "rtc-core.h" |
e824290e | 18 | |
e824290e AZ |
19 | static dev_t rtc_devt; |
20 | ||
21 | #define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */ | |
22 | ||
23 | static int rtc_dev_open(struct inode *inode, struct file *file) | |
24 | { | |
25 | int err; | |
26 | struct rtc_device *rtc = container_of(inode->i_cdev, | |
27 | struct rtc_device, char_dev); | |
ff8371ac | 28 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e | 29 | |
b1c3c898 DB |
30 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
31 | return -EBUSY; | |
e824290e | 32 | |
ab6a2d70 | 33 | file->private_data = rtc; |
e824290e | 34 | |
cd966209 | 35 | err = ops->open ? ops->open(rtc->dev.parent) : 0; |
e824290e AZ |
36 | if (err == 0) { |
37 | spin_lock_irq(&rtc->irq_lock); | |
38 | rtc->irq_data = 0; | |
39 | spin_unlock_irq(&rtc->irq_lock); | |
40 | ||
b1c3c898 | 41 | return 0; |
e824290e AZ |
42 | } |
43 | ||
8853c202 | 44 | /* something has gone wrong */ |
372a302e | 45 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
e824290e AZ |
46 | return err; |
47 | } | |
48 | ||
655066c3 AN |
49 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
50 | /* | |
51 | * Routine to poll RTC seconds field for change as often as possible, | |
52 | * after first RTC_UIE use timer to reduce polling | |
53 | */ | |
c4028958 | 54 | static void rtc_uie_task(struct work_struct *work) |
655066c3 | 55 | { |
c4028958 DH |
56 | struct rtc_device *rtc = |
57 | container_of(work, struct rtc_device, uie_task); | |
655066c3 AN |
58 | struct rtc_time tm; |
59 | int num = 0; | |
60 | int err; | |
61 | ||
ab6a2d70 | 62 | err = rtc_read_time(rtc, &tm); |
d728b1e6 | 63 | |
e6229bec | 64 | spin_lock_irq(&rtc->irq_lock); |
655066c3 AN |
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 | } | |
e6229bec | 77 | spin_unlock_irq(&rtc->irq_lock); |
655066c3 | 78 | if (num) |
ab6a2d70 | 79 | rtc_update_irq(rtc, num, RTC_UF | RTC_IRQF); |
655066c3 | 80 | } |
655066c3 AN |
81 | static void rtc_uie_timer(unsigned long data) |
82 | { | |
83 | struct rtc_device *rtc = (struct rtc_device *)data; | |
84 | unsigned long flags; | |
85 | ||
86 | spin_lock_irqsave(&rtc->irq_lock, flags); | |
87 | rtc->uie_timer_active = 0; | |
88 | rtc->uie_task_active = 1; | |
89 | if ((schedule_work(&rtc->uie_task) == 0)) | |
90 | rtc->uie_task_active = 0; | |
91 | spin_unlock_irqrestore(&rtc->irq_lock, flags); | |
92 | } | |
93 | ||
099e6576 | 94 | static int clear_uie(struct rtc_device *rtc) |
655066c3 AN |
95 | { |
96 | spin_lock_irq(&rtc->irq_lock); | |
099e6576 | 97 | if (rtc->uie_irq_active) { |
655066c3 AN |
98 | rtc->stop_uie_polling = 1; |
99 | if (rtc->uie_timer_active) { | |
100 | spin_unlock_irq(&rtc->irq_lock); | |
101 | del_timer_sync(&rtc->uie_timer); | |
102 | spin_lock_irq(&rtc->irq_lock); | |
103 | rtc->uie_timer_active = 0; | |
104 | } | |
105 | if (rtc->uie_task_active) { | |
106 | spin_unlock_irq(&rtc->irq_lock); | |
107 | flush_scheduled_work(); | |
108 | spin_lock_irq(&rtc->irq_lock); | |
109 | } | |
099e6576 | 110 | rtc->uie_irq_active = 0; |
655066c3 AN |
111 | } |
112 | spin_unlock_irq(&rtc->irq_lock); | |
099e6576 | 113 | return 0; |
655066c3 AN |
114 | } |
115 | ||
116 | static int set_uie(struct rtc_device *rtc) | |
117 | { | |
118 | struct rtc_time tm; | |
119 | int err; | |
120 | ||
ab6a2d70 | 121 | err = rtc_read_time(rtc, &tm); |
655066c3 AN |
122 | if (err) |
123 | return err; | |
124 | spin_lock_irq(&rtc->irq_lock); | |
099e6576 AZ |
125 | if (!rtc->uie_irq_active) { |
126 | rtc->uie_irq_active = 1; | |
655066c3 AN |
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 | } | |
099e6576 AZ |
137 | |
138 | int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled) | |
139 | { | |
140 | if (enabled) | |
141 | return set_uie(rtc); | |
142 | else | |
143 | return clear_uie(rtc); | |
144 | } | |
145 | EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul); | |
146 | ||
655066c3 | 147 | #endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */ |
e824290e AZ |
148 | |
149 | static ssize_t | |
150 | rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
151 | { | |
88efe137 | 152 | struct rtc_device *rtc = file->private_data; |
e824290e AZ |
153 | |
154 | DECLARE_WAITQUEUE(wait, current); | |
155 | unsigned long data; | |
156 | ssize_t ret; | |
157 | ||
3418ff76 | 158 | if (count != sizeof(unsigned int) && count < sizeof(unsigned long)) |
e824290e AZ |
159 | return -EINVAL; |
160 | ||
161 | add_wait_queue(&rtc->irq_queue, &wait); | |
162 | do { | |
163 | __set_current_state(TASK_INTERRUPTIBLE); | |
164 | ||
165 | spin_lock_irq(&rtc->irq_lock); | |
166 | data = rtc->irq_data; | |
167 | rtc->irq_data = 0; | |
168 | spin_unlock_irq(&rtc->irq_lock); | |
169 | ||
170 | if (data != 0) { | |
171 | ret = 0; | |
172 | break; | |
173 | } | |
174 | if (file->f_flags & O_NONBLOCK) { | |
175 | ret = -EAGAIN; | |
176 | break; | |
177 | } | |
178 | if (signal_pending(current)) { | |
179 | ret = -ERESTARTSYS; | |
180 | break; | |
181 | } | |
182 | schedule(); | |
183 | } while (1); | |
184 | set_current_state(TASK_RUNNING); | |
185 | remove_wait_queue(&rtc->irq_queue, &wait); | |
186 | ||
187 | if (ret == 0) { | |
188 | /* Check for any data updates */ | |
189 | if (rtc->ops->read_callback) | |
cd966209 | 190 | data = rtc->ops->read_callback(rtc->dev.parent, |
3418ff76 AN |
191 | data); |
192 | ||
193 | if (sizeof(int) != sizeof(long) && | |
194 | count == sizeof(unsigned int)) | |
195 | ret = put_user(data, (unsigned int __user *)buf) ?: | |
196 | sizeof(unsigned int); | |
197 | else | |
198 | ret = put_user(data, (unsigned long __user *)buf) ?: | |
199 | sizeof(unsigned long); | |
e824290e AZ |
200 | } |
201 | return ret; | |
202 | } | |
203 | ||
204 | static unsigned int rtc_dev_poll(struct file *file, poll_table *wait) | |
205 | { | |
88efe137 | 206 | struct rtc_device *rtc = file->private_data; |
e824290e AZ |
207 | unsigned long data; |
208 | ||
209 | poll_wait(file, &rtc->irq_queue, wait); | |
210 | ||
211 | data = rtc->irq_data; | |
212 | ||
213 | return (data != 0) ? (POLLIN | POLLRDNORM) : 0; | |
214 | } | |
215 | ||
5ad31a57 | 216 | static long rtc_dev_ioctl(struct file *file, |
e824290e AZ |
217 | unsigned int cmd, unsigned long arg) |
218 | { | |
219 | int err = 0; | |
ab6a2d70 | 220 | struct rtc_device *rtc = file->private_data; |
ff8371ac | 221 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e AZ |
222 | struct rtc_time tm; |
223 | struct rtc_wkalrm alarm; | |
224 | void __user *uarg = (void __user *) arg; | |
225 | ||
5ad31a57 DB |
226 | err = mutex_lock_interruptible(&rtc->ops_lock); |
227 | if (err) | |
b68bb263 | 228 | return err; |
5ad31a57 | 229 | |
2601a464 | 230 | /* check that the calling task has appropriate permissions |
110d693d AZ |
231 | * for certain ioctls. doing this check here is useful |
232 | * to avoid duplicate code in each driver. | |
233 | */ | |
234 | switch (cmd) { | |
235 | case RTC_EPOCH_SET: | |
236 | case RTC_SET_TIME: | |
237 | if (!capable(CAP_SYS_TIME)) | |
5ad31a57 | 238 | err = -EACCES; |
110d693d AZ |
239 | break; |
240 | ||
241 | case RTC_IRQP_SET: | |
242 | if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) | |
5ad31a57 | 243 | err = -EACCES; |
110d693d AZ |
244 | break; |
245 | ||
246 | case RTC_PIE_ON: | |
9d013d3b BK |
247 | if (rtc->irq_freq > rtc->max_user_freq && |
248 | !capable(CAP_SYS_RESOURCE)) | |
5ad31a57 | 249 | err = -EACCES; |
110d693d AZ |
250 | break; |
251 | } | |
252 | ||
5ad31a57 DB |
253 | if (err) |
254 | goto done; | |
255 | ||
e824290e AZ |
256 | /* try the driver's ioctl interface */ |
257 | if (ops->ioctl) { | |
cd966209 | 258 | err = ops->ioctl(rtc->dev.parent, cmd, arg); |
5ad31a57 DB |
259 | if (err != -ENOIOCTLCMD) { |
260 | mutex_unlock(&rtc->ops_lock); | |
e824290e | 261 | return err; |
5ad31a57 | 262 | } |
e824290e AZ |
263 | } |
264 | ||
265 | /* if the driver does not provide the ioctl interface | |
266 | * or if that particular ioctl was not implemented | |
b3969e58 | 267 | * (-ENOIOCTLCMD), we will try to emulate here. |
8a0bdfd7 DB |
268 | * |
269 | * Drivers *SHOULD NOT* provide ioctl implementations | |
270 | * for these requests. Instead, provide methods to | |
271 | * support the following code, so that the RTC's main | |
272 | * features are accessible without using ioctls. | |
273 | * | |
274 | * RTC and alarm times will be in UTC, by preference, | |
275 | * but dual-booting with MS-Windows implies RTCs must | |
276 | * use the local wall clock time. | |
e824290e AZ |
277 | */ |
278 | ||
279 | switch (cmd) { | |
280 | case RTC_ALM_READ: | |
5ad31a57 DB |
281 | mutex_unlock(&rtc->ops_lock); |
282 | ||
ab6a2d70 | 283 | err = rtc_read_alarm(rtc, &alarm); |
e824290e AZ |
284 | if (err < 0) |
285 | return err; | |
286 | ||
287 | if (copy_to_user(uarg, &alarm.time, sizeof(tm))) | |
5ad31a57 DB |
288 | err = -EFAULT; |
289 | return err; | |
e824290e AZ |
290 | |
291 | case RTC_ALM_SET: | |
5ad31a57 DB |
292 | mutex_unlock(&rtc->ops_lock); |
293 | ||
e824290e AZ |
294 | if (copy_from_user(&alarm.time, uarg, sizeof(tm))) |
295 | return -EFAULT; | |
296 | ||
297 | alarm.enabled = 0; | |
298 | alarm.pending = 0; | |
e824290e AZ |
299 | alarm.time.tm_wday = -1; |
300 | alarm.time.tm_yday = -1; | |
301 | alarm.time.tm_isdst = -1; | |
f8245c26 DB |
302 | |
303 | /* RTC_ALM_SET alarms may be up to 24 hours in the future. | |
304 | * Rather than expecting every RTC to implement "don't care" | |
305 | * for day/month/year fields, just force the alarm to have | |
306 | * the right values for those fields. | |
307 | * | |
308 | * RTC_WKALM_SET should be used instead. Not only does it | |
309 | * eliminate the need for a separate RTC_AIE_ON call, it | |
310 | * doesn't have the "alarm 23:59:59 in the future" race. | |
311 | * | |
312 | * NOTE: some legacy code may have used invalid fields as | |
313 | * wildcards, exposing hardware "periodic alarm" capabilities. | |
314 | * Not supported here. | |
315 | */ | |
316 | { | |
317 | unsigned long now, then; | |
318 | ||
319 | err = rtc_read_time(rtc, &tm); | |
320 | if (err < 0) | |
321 | return err; | |
322 | rtc_tm_to_time(&tm, &now); | |
323 | ||
324 | alarm.time.tm_mday = tm.tm_mday; | |
325 | alarm.time.tm_mon = tm.tm_mon; | |
326 | alarm.time.tm_year = tm.tm_year; | |
327 | err = rtc_valid_tm(&alarm.time); | |
328 | if (err < 0) | |
329 | return err; | |
330 | rtc_tm_to_time(&alarm.time, &then); | |
331 | ||
332 | /* alarm may need to wrap into tomorrow */ | |
333 | if (then < now) { | |
334 | rtc_time_to_tm(now + 24 * 60 * 60, &tm); | |
335 | alarm.time.tm_mday = tm.tm_mday; | |
336 | alarm.time.tm_mon = tm.tm_mon; | |
337 | alarm.time.tm_year = tm.tm_year; | |
338 | } | |
339 | } | |
340 | ||
5ad31a57 | 341 | return rtc_set_alarm(rtc, &alarm); |
e824290e AZ |
342 | |
343 | case RTC_RD_TIME: | |
5ad31a57 DB |
344 | mutex_unlock(&rtc->ops_lock); |
345 | ||
ab6a2d70 | 346 | err = rtc_read_time(rtc, &tm); |
e824290e AZ |
347 | if (err < 0) |
348 | return err; | |
349 | ||
350 | if (copy_to_user(uarg, &tm, sizeof(tm))) | |
5ad31a57 DB |
351 | err = -EFAULT; |
352 | return err; | |
e824290e AZ |
353 | |
354 | case RTC_SET_TIME: | |
5ad31a57 DB |
355 | mutex_unlock(&rtc->ops_lock); |
356 | ||
e824290e AZ |
357 | if (copy_from_user(&tm, uarg, sizeof(tm))) |
358 | return -EFAULT; | |
359 | ||
5ad31a57 | 360 | return rtc_set_time(rtc, &tm); |
2601a464 | 361 | |
d691eb90 AZ |
362 | case RTC_PIE_ON: |
363 | err = rtc_irq_set_state(rtc, NULL, 1); | |
364 | break; | |
365 | ||
366 | case RTC_PIE_OFF: | |
367 | err = rtc_irq_set_state(rtc, NULL, 0); | |
2601a464 DB |
368 | break; |
369 | ||
099e6576 AZ |
370 | case RTC_AIE_ON: |
371 | mutex_unlock(&rtc->ops_lock); | |
372 | return rtc_alarm_irq_enable(rtc, 1); | |
373 | ||
374 | case RTC_AIE_OFF: | |
375 | mutex_unlock(&rtc->ops_lock); | |
376 | return rtc_alarm_irq_enable(rtc, 0); | |
377 | ||
378 | case RTC_UIE_ON: | |
379 | mutex_unlock(&rtc->ops_lock); | |
380 | return rtc_update_irq_enable(rtc, 1); | |
381 | ||
382 | case RTC_UIE_OFF: | |
383 | mutex_unlock(&rtc->ops_lock); | |
384 | return rtc_update_irq_enable(rtc, 0); | |
385 | ||
2601a464 | 386 | case RTC_IRQP_SET: |
d691eb90 AZ |
387 | err = rtc_irq_set_freq(rtc, NULL, arg); |
388 | break; | |
389 | ||
390 | case RTC_IRQP_READ: | |
391 | err = put_user(rtc->irq_freq, (unsigned long __user *)uarg); | |
2601a464 DB |
392 | break; |
393 | ||
e824290e AZ |
394 | #if 0 |
395 | case RTC_EPOCH_SET: | |
396 | #ifndef rtc_epoch | |
397 | /* | |
398 | * There were no RTC clocks before 1900. | |
399 | */ | |
400 | if (arg < 1900) { | |
401 | err = -EINVAL; | |
402 | break; | |
403 | } | |
e824290e AZ |
404 | rtc_epoch = arg; |
405 | err = 0; | |
406 | #endif | |
407 | break; | |
408 | ||
409 | case RTC_EPOCH_READ: | |
410 | err = put_user(rtc_epoch, (unsigned long __user *)uarg); | |
411 | break; | |
412 | #endif | |
413 | case RTC_WKALM_SET: | |
5ad31a57 | 414 | mutex_unlock(&rtc->ops_lock); |
e824290e AZ |
415 | if (copy_from_user(&alarm, uarg, sizeof(alarm))) |
416 | return -EFAULT; | |
417 | ||
5ad31a57 | 418 | return rtc_set_alarm(rtc, &alarm); |
e824290e AZ |
419 | |
420 | case RTC_WKALM_RD: | |
5ad31a57 | 421 | mutex_unlock(&rtc->ops_lock); |
ab6a2d70 | 422 | err = rtc_read_alarm(rtc, &alarm); |
e824290e AZ |
423 | if (err < 0) |
424 | return err; | |
425 | ||
426 | if (copy_to_user(uarg, &alarm, sizeof(alarm))) | |
5ad31a57 DB |
427 | err = -EFAULT; |
428 | return err; | |
e824290e AZ |
429 | |
430 | default: | |
b3969e58 | 431 | err = -ENOTTY; |
e824290e AZ |
432 | break; |
433 | } | |
434 | ||
5ad31a57 DB |
435 | done: |
436 | mutex_unlock(&rtc->ops_lock); | |
e824290e AZ |
437 | return err; |
438 | } | |
439 | ||
2e4a75cd MS |
440 | static int rtc_dev_fasync(int fd, struct file *file, int on) |
441 | { | |
442 | struct rtc_device *rtc = file->private_data; | |
443 | return fasync_helper(fd, file, on, &rtc->async_queue); | |
444 | } | |
445 | ||
e824290e AZ |
446 | static int rtc_dev_release(struct inode *inode, struct file *file) |
447 | { | |
88efe137 | 448 | struct rtc_device *rtc = file->private_data; |
e824290e | 449 | |
743e6a50 DB |
450 | /* We shut down the repeating IRQs that userspace enabled, |
451 | * since nothing is listening to them. | |
452 | * - Update (UIE) ... currently only managed through ioctls | |
453 | * - Periodic (PIE) ... also used through rtc_*() interface calls | |
454 | * | |
455 | * Leave the alarm alone; it may be set to trigger a system wakeup | |
456 | * later, or be used by kernel code, and is a one-shot event anyway. | |
457 | */ | |
099e6576 AZ |
458 | |
459 | /* Keep ioctl until all drivers are converted */ | |
743e6a50 | 460 | rtc_dev_ioctl(file, RTC_UIE_OFF, 0); |
099e6576 | 461 | rtc_update_irq_enable(rtc, 0); |
5cdc98b8 TJ |
462 | rtc_irq_set_state(rtc, NULL, 0); |
463 | ||
e824290e | 464 | if (rtc->ops->release) |
cd966209 | 465 | rtc->ops->release(rtc->dev.parent); |
e824290e | 466 | |
372a302e | 467 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
e824290e AZ |
468 | return 0; |
469 | } | |
470 | ||
d54b1fdb | 471 | static const struct file_operations rtc_dev_fops = { |
e824290e AZ |
472 | .owner = THIS_MODULE, |
473 | .llseek = no_llseek, | |
474 | .read = rtc_dev_read, | |
475 | .poll = rtc_dev_poll, | |
5ad31a57 | 476 | .unlocked_ioctl = rtc_dev_ioctl, |
e824290e AZ |
477 | .open = rtc_dev_open, |
478 | .release = rtc_dev_release, | |
479 | .fasync = rtc_dev_fasync, | |
480 | }; | |
481 | ||
482 | /* insertion/removal hooks */ | |
483 | ||
cb3a58d2 | 484 | void rtc_dev_prepare(struct rtc_device *rtc) |
e824290e | 485 | { |
5726fb20 DB |
486 | if (!rtc_devt) |
487 | return; | |
e824290e AZ |
488 | |
489 | if (rtc->id >= RTC_DEV_MAX) { | |
5726fb20 DB |
490 | pr_debug("%s: too many RTC devices\n", rtc->name); |
491 | return; | |
e824290e AZ |
492 | } |
493 | ||
cd966209 | 494 | rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id); |
5726fb20 | 495 | |
655066c3 | 496 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
c4028958 | 497 | INIT_WORK(&rtc->uie_task, rtc_uie_task); |
655066c3 AN |
498 | setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc); |
499 | #endif | |
e824290e AZ |
500 | |
501 | cdev_init(&rtc->char_dev, &rtc_dev_fops); | |
502 | rtc->char_dev.owner = rtc->owner; | |
cb3a58d2 | 503 | } |
e824290e | 504 | |
cb3a58d2 DB |
505 | void rtc_dev_add_device(struct rtc_device *rtc) |
506 | { | |
cd966209 | 507 | if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1)) |
5726fb20 DB |
508 | printk(KERN_WARNING "%s: failed to add char device %d:%d\n", |
509 | rtc->name, MAJOR(rtc_devt), rtc->id); | |
510 | else | |
511 | pr_debug("%s: dev (%d:%d)\n", rtc->name, | |
e824290e | 512 | MAJOR(rtc_devt), rtc->id); |
e824290e AZ |
513 | } |
514 | ||
5726fb20 | 515 | void rtc_dev_del_device(struct rtc_device *rtc) |
e824290e | 516 | { |
cd966209 | 517 | if (rtc->dev.devt) |
e824290e | 518 | cdev_del(&rtc->char_dev); |
e824290e AZ |
519 | } |
520 | ||
5726fb20 | 521 | void __init rtc_dev_init(void) |
e824290e AZ |
522 | { |
523 | int err; | |
524 | ||
e824290e | 525 | err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc"); |
5726fb20 | 526 | if (err < 0) |
e824290e AZ |
527 | printk(KERN_ERR "%s: failed to allocate char dev region\n", |
528 | __FILE__); | |
e824290e AZ |
529 | } |
530 | ||
5726fb20 | 531 | void __exit rtc_dev_exit(void) |
e824290e | 532 | { |
5726fb20 DB |
533 | if (rtc_devt) |
534 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); | |
e824290e | 535 | } |