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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> | |
5726fb20 | 16 | #include "rtc-core.h" |
e824290e | 17 | |
e824290e AZ |
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); | |
ff8371ac | 27 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e | 28 | |
b1c3c898 DB |
29 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
30 | return -EBUSY; | |
e824290e | 31 | |
ab6a2d70 | 32 | file->private_data = rtc; |
e824290e | 33 | |
cd966209 | 34 | err = ops->open ? ops->open(rtc->dev.parent) : 0; |
e824290e AZ |
35 | if (err == 0) { |
36 | spin_lock_irq(&rtc->irq_lock); | |
37 | rtc->irq_data = 0; | |
38 | spin_unlock_irq(&rtc->irq_lock); | |
39 | ||
b1c3c898 | 40 | return 0; |
e824290e AZ |
41 | } |
42 | ||
8853c202 | 43 | /* something has gone wrong */ |
372a302e | 44 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
e824290e AZ |
45 | return err; |
46 | } | |
47 | ||
655066c3 AN |
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 | */ | |
c4028958 | 53 | static void rtc_uie_task(struct work_struct *work) |
655066c3 | 54 | { |
c4028958 DH |
55 | struct rtc_device *rtc = |
56 | container_of(work, struct rtc_device, uie_task); | |
655066c3 AN |
57 | struct rtc_time tm; |
58 | int num = 0; | |
59 | int err; | |
60 | ||
ab6a2d70 | 61 | err = rtc_read_time(rtc, &tm); |
d728b1e6 DB |
62 | |
63 | local_irq_disable(); | |
64 | spin_lock(&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 | } | |
d728b1e6 | 77 | spin_unlock(&rtc->irq_lock); |
655066c3 | 78 | if (num) |
ab6a2d70 | 79 | rtc_update_irq(rtc, num, RTC_UF | RTC_IRQF); |
d728b1e6 | 80 | local_irq_enable(); |
655066c3 | 81 | } |
655066c3 AN |
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 | ||
ab6a2d70 | 121 | err = rtc_read_time(rtc, &tm); |
655066c3 AN |
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 */ | |
e824290e AZ |
138 | |
139 | static ssize_t | |
140 | rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
141 | { | |
88efe137 | 142 | struct rtc_device *rtc = file->private_data; |
e824290e AZ |
143 | |
144 | DECLARE_WAITQUEUE(wait, current); | |
145 | unsigned long data; | |
146 | ssize_t ret; | |
147 | ||
3418ff76 | 148 | if (count != sizeof(unsigned int) && count < sizeof(unsigned long)) |
e824290e AZ |
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) | |
cd966209 | 180 | data = rtc->ops->read_callback(rtc->dev.parent, |
3418ff76 AN |
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); | |
e824290e AZ |
190 | } |
191 | return ret; | |
192 | } | |
193 | ||
194 | static unsigned int rtc_dev_poll(struct file *file, poll_table *wait) | |
195 | { | |
88efe137 | 196 | struct rtc_device *rtc = file->private_data; |
e824290e AZ |
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 | ||
5ad31a57 | 206 | static long rtc_dev_ioctl(struct file *file, |
e824290e AZ |
207 | unsigned int cmd, unsigned long arg) |
208 | { | |
209 | int err = 0; | |
ab6a2d70 | 210 | struct rtc_device *rtc = file->private_data; |
ff8371ac | 211 | const struct rtc_class_ops *ops = rtc->ops; |
e824290e AZ |
212 | struct rtc_time tm; |
213 | struct rtc_wkalrm alarm; | |
214 | void __user *uarg = (void __user *) arg; | |
215 | ||
5ad31a57 DB |
216 | err = mutex_lock_interruptible(&rtc->ops_lock); |
217 | if (err) | |
b68bb263 | 218 | return err; |
5ad31a57 | 219 | |
2601a464 | 220 | /* check that the calling task has appropriate permissions |
110d693d AZ |
221 | * for certain ioctls. doing this check here is useful |
222 | * to avoid duplicate code in each driver. | |
223 | */ | |
224 | switch (cmd) { | |
225 | case RTC_EPOCH_SET: | |
226 | case RTC_SET_TIME: | |
227 | if (!capable(CAP_SYS_TIME)) | |
5ad31a57 | 228 | err = -EACCES; |
110d693d AZ |
229 | break; |
230 | ||
231 | case RTC_IRQP_SET: | |
232 | if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) | |
5ad31a57 | 233 | err = -EACCES; |
110d693d AZ |
234 | break; |
235 | ||
236 | case RTC_PIE_ON: | |
9d013d3b BK |
237 | if (rtc->irq_freq > rtc->max_user_freq && |
238 | !capable(CAP_SYS_RESOURCE)) | |
5ad31a57 | 239 | err = -EACCES; |
110d693d AZ |
240 | break; |
241 | } | |
242 | ||
5ad31a57 DB |
243 | if (err) |
244 | goto done; | |
245 | ||
e824290e AZ |
246 | /* try the driver's ioctl interface */ |
247 | if (ops->ioctl) { | |
cd966209 | 248 | err = ops->ioctl(rtc->dev.parent, cmd, arg); |
5ad31a57 DB |
249 | if (err != -ENOIOCTLCMD) { |
250 | mutex_unlock(&rtc->ops_lock); | |
e824290e | 251 | return err; |
5ad31a57 | 252 | } |
e824290e AZ |
253 | } |
254 | ||
255 | /* if the driver does not provide the ioctl interface | |
256 | * or if that particular ioctl was not implemented | |
b3969e58 | 257 | * (-ENOIOCTLCMD), we will try to emulate here. |
8a0bdfd7 DB |
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. | |
e824290e AZ |
267 | */ |
268 | ||
269 | switch (cmd) { | |
270 | case RTC_ALM_READ: | |
5ad31a57 DB |
271 | mutex_unlock(&rtc->ops_lock); |
272 | ||
ab6a2d70 | 273 | err = rtc_read_alarm(rtc, &alarm); |
e824290e AZ |
274 | if (err < 0) |
275 | return err; | |
276 | ||
277 | if (copy_to_user(uarg, &alarm.time, sizeof(tm))) | |
5ad31a57 DB |
278 | err = -EFAULT; |
279 | return err; | |
e824290e AZ |
280 | |
281 | case RTC_ALM_SET: | |
5ad31a57 DB |
282 | mutex_unlock(&rtc->ops_lock); |
283 | ||
e824290e AZ |
284 | if (copy_from_user(&alarm.time, uarg, sizeof(tm))) |
285 | return -EFAULT; | |
286 | ||
287 | alarm.enabled = 0; | |
288 | alarm.pending = 0; | |
e824290e AZ |
289 | alarm.time.tm_wday = -1; |
290 | alarm.time.tm_yday = -1; | |
291 | alarm.time.tm_isdst = -1; | |
f8245c26 DB |
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 | unsigned long now, then; | |
308 | ||
309 | err = rtc_read_time(rtc, &tm); | |
310 | if (err < 0) | |
311 | return err; | |
312 | rtc_tm_to_time(&tm, &now); | |
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 | rtc_tm_to_time(&alarm.time, &then); | |
321 | ||
322 | /* alarm may need to wrap into tomorrow */ | |
323 | if (then < now) { | |
324 | rtc_time_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 | ||
5ad31a57 | 331 | return rtc_set_alarm(rtc, &alarm); |
e824290e AZ |
332 | |
333 | case RTC_RD_TIME: | |
5ad31a57 DB |
334 | mutex_unlock(&rtc->ops_lock); |
335 | ||
ab6a2d70 | 336 | err = rtc_read_time(rtc, &tm); |
e824290e AZ |
337 | if (err < 0) |
338 | return err; | |
339 | ||
340 | if (copy_to_user(uarg, &tm, sizeof(tm))) | |
5ad31a57 DB |
341 | err = -EFAULT; |
342 | return err; | |
e824290e AZ |
343 | |
344 | case RTC_SET_TIME: | |
5ad31a57 DB |
345 | mutex_unlock(&rtc->ops_lock); |
346 | ||
e824290e AZ |
347 | if (copy_from_user(&tm, uarg, sizeof(tm))) |
348 | return -EFAULT; | |
349 | ||
5ad31a57 | 350 | return rtc_set_time(rtc, &tm); |
2601a464 | 351 | |
d691eb90 AZ |
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); | |
2601a464 DB |
358 | break; |
359 | ||
360 | case RTC_IRQP_SET: | |
d691eb90 AZ |
361 | err = rtc_irq_set_freq(rtc, NULL, arg); |
362 | break; | |
363 | ||
364 | case RTC_IRQP_READ: | |
365 | err = put_user(rtc->irq_freq, (unsigned long __user *)uarg); | |
2601a464 DB |
366 | break; |
367 | ||
e824290e AZ |
368 | #if 0 |
369 | case RTC_EPOCH_SET: | |
370 | #ifndef rtc_epoch | |
371 | /* | |
372 | * There were no RTC clocks before 1900. | |
373 | */ | |
374 | if (arg < 1900) { | |
375 | err = -EINVAL; | |
376 | break; | |
377 | } | |
e824290e AZ |
378 | rtc_epoch = arg; |
379 | err = 0; | |
380 | #endif | |
381 | break; | |
382 | ||
383 | case RTC_EPOCH_READ: | |
384 | err = put_user(rtc_epoch, (unsigned long __user *)uarg); | |
385 | break; | |
386 | #endif | |
387 | case RTC_WKALM_SET: | |
5ad31a57 | 388 | mutex_unlock(&rtc->ops_lock); |
e824290e AZ |
389 | if (copy_from_user(&alarm, uarg, sizeof(alarm))) |
390 | return -EFAULT; | |
391 | ||
5ad31a57 | 392 | return rtc_set_alarm(rtc, &alarm); |
e824290e AZ |
393 | |
394 | case RTC_WKALM_RD: | |
5ad31a57 | 395 | mutex_unlock(&rtc->ops_lock); |
ab6a2d70 | 396 | err = rtc_read_alarm(rtc, &alarm); |
e824290e AZ |
397 | if (err < 0) |
398 | return err; | |
399 | ||
400 | if (copy_to_user(uarg, &alarm, sizeof(alarm))) | |
5ad31a57 DB |
401 | err = -EFAULT; |
402 | return err; | |
e824290e | 403 | |
655066c3 AN |
404 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
405 | case RTC_UIE_OFF: | |
1d96469a | 406 | mutex_unlock(&rtc->ops_lock); |
655066c3 | 407 | clear_uie(rtc); |
1d96469a | 408 | return 0; |
655066c3 AN |
409 | |
410 | case RTC_UIE_ON: | |
1d96469a | 411 | mutex_unlock(&rtc->ops_lock); |
5ad31a57 | 412 | err = set_uie(rtc); |
1d96469a | 413 | return err; |
655066c3 | 414 | #endif |
e824290e | 415 | default: |
b3969e58 | 416 | err = -ENOTTY; |
e824290e AZ |
417 | break; |
418 | } | |
419 | ||
5ad31a57 DB |
420 | done: |
421 | mutex_unlock(&rtc->ops_lock); | |
e824290e AZ |
422 | return err; |
423 | } | |
424 | ||
2e4a75cd MS |
425 | static int rtc_dev_fasync(int fd, struct file *file, int on) |
426 | { | |
427 | struct rtc_device *rtc = file->private_data; | |
428 | return fasync_helper(fd, file, on, &rtc->async_queue); | |
429 | } | |
430 | ||
e824290e AZ |
431 | static int rtc_dev_release(struct inode *inode, struct file *file) |
432 | { | |
88efe137 | 433 | struct rtc_device *rtc = file->private_data; |
e824290e | 434 | |
655066c3 AN |
435 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
436 | clear_uie(rtc); | |
437 | #endif | |
5cdc98b8 TJ |
438 | rtc_irq_set_state(rtc, NULL, 0); |
439 | ||
e824290e | 440 | if (rtc->ops->release) |
cd966209 | 441 | rtc->ops->release(rtc->dev.parent); |
e824290e | 442 | |
2e4a75cd MS |
443 | if (file->f_flags & FASYNC) |
444 | rtc_dev_fasync(-1, file, 0); | |
445 | ||
372a302e | 446 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
e824290e AZ |
447 | return 0; |
448 | } | |
449 | ||
d54b1fdb | 450 | static const struct file_operations rtc_dev_fops = { |
e824290e AZ |
451 | .owner = THIS_MODULE, |
452 | .llseek = no_llseek, | |
453 | .read = rtc_dev_read, | |
454 | .poll = rtc_dev_poll, | |
5ad31a57 | 455 | .unlocked_ioctl = rtc_dev_ioctl, |
e824290e AZ |
456 | .open = rtc_dev_open, |
457 | .release = rtc_dev_release, | |
458 | .fasync = rtc_dev_fasync, | |
459 | }; | |
460 | ||
461 | /* insertion/removal hooks */ | |
462 | ||
cb3a58d2 | 463 | void rtc_dev_prepare(struct rtc_device *rtc) |
e824290e | 464 | { |
5726fb20 DB |
465 | if (!rtc_devt) |
466 | return; | |
e824290e AZ |
467 | |
468 | if (rtc->id >= RTC_DEV_MAX) { | |
5726fb20 DB |
469 | pr_debug("%s: too many RTC devices\n", rtc->name); |
470 | return; | |
e824290e AZ |
471 | } |
472 | ||
cd966209 | 473 | rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id); |
5726fb20 | 474 | |
655066c3 | 475 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
c4028958 | 476 | INIT_WORK(&rtc->uie_task, rtc_uie_task); |
655066c3 AN |
477 | setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc); |
478 | #endif | |
e824290e AZ |
479 | |
480 | cdev_init(&rtc->char_dev, &rtc_dev_fops); | |
481 | rtc->char_dev.owner = rtc->owner; | |
cb3a58d2 | 482 | } |
e824290e | 483 | |
cb3a58d2 DB |
484 | void rtc_dev_add_device(struct rtc_device *rtc) |
485 | { | |
cd966209 | 486 | if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1)) |
5726fb20 DB |
487 | printk(KERN_WARNING "%s: failed to add char device %d:%d\n", |
488 | rtc->name, MAJOR(rtc_devt), rtc->id); | |
489 | else | |
490 | pr_debug("%s: dev (%d:%d)\n", rtc->name, | |
e824290e | 491 | MAJOR(rtc_devt), rtc->id); |
e824290e AZ |
492 | } |
493 | ||
5726fb20 | 494 | void rtc_dev_del_device(struct rtc_device *rtc) |
e824290e | 495 | { |
cd966209 | 496 | if (rtc->dev.devt) |
e824290e | 497 | cdev_del(&rtc->char_dev); |
e824290e AZ |
498 | } |
499 | ||
5726fb20 | 500 | void __init rtc_dev_init(void) |
e824290e AZ |
501 | { |
502 | int err; | |
503 | ||
e824290e | 504 | err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc"); |
5726fb20 | 505 | if (err < 0) |
e824290e AZ |
506 | printk(KERN_ERR "%s: failed to allocate char dev region\n", |
507 | __FILE__); | |
e824290e AZ |
508 | } |
509 | ||
5726fb20 | 510 | void __exit rtc_dev_exit(void) |
e824290e | 511 | { |
5726fb20 DB |
512 | if (rtc_devt) |
513 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); | |
e824290e | 514 | } |