Root/
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 <linux/sched.h> |
17 | #include "rtc-core.h" |
18 | |
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); |
28 | const struct rtc_class_ops *ops = rtc->ops; |
29 | |
30 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
31 | return -EBUSY; |
32 | |
33 | file->private_data = rtc; |
34 | |
35 | err = ops->open ? ops->open(rtc->dev.parent) : 0; |
36 | if (err == 0) { |
37 | spin_lock_irq(&rtc->irq_lock); |
38 | rtc->irq_data = 0; |
39 | spin_unlock_irq(&rtc->irq_lock); |
40 | |
41 | return 0; |
42 | } |
43 | |
44 | /* something has gone wrong */ |
45 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
46 | return err; |
47 | } |
48 | |
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 | */ |
54 | static void rtc_uie_task(struct work_struct *work) |
55 | { |
56 | struct rtc_device *rtc = |
57 | container_of(work, struct rtc_device, uie_task); |
58 | struct rtc_time tm; |
59 | int num = 0; |
60 | int err; |
61 | |
62 | err = rtc_read_time(rtc, &tm); |
63 | |
64 | spin_lock_irq(&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_irq(&rtc->irq_lock); |
78 | if (num) |
79 | rtc_update_irq(rtc, num, RTC_UF | RTC_IRQF); |
80 | } |
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 | |
94 | static int clear_uie(struct rtc_device *rtc) |
95 | { |
96 | spin_lock_irq(&rtc->irq_lock); |
97 | if (rtc->uie_irq_active) { |
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 | } |
110 | rtc->uie_irq_active = 0; |
111 | } |
112 | spin_unlock_irq(&rtc->irq_lock); |
113 | return 0; |
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->uie_irq_active) { |
126 | rtc->uie_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 | |
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 | |
147 | #endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */ |
148 | |
149 | static ssize_t |
150 | rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
151 | { |
152 | struct rtc_device *rtc = file->private_data; |
153 | |
154 | DECLARE_WAITQUEUE(wait, current); |
155 | unsigned long data; |
156 | ssize_t ret; |
157 | |
158 | if (count != sizeof(unsigned int) && count < sizeof(unsigned long)) |
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) |
190 | data = rtc->ops->read_callback(rtc->dev.parent, |
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); |
200 | } |
201 | return ret; |
202 | } |
203 | |
204 | static unsigned int rtc_dev_poll(struct file *file, poll_table *wait) |
205 | { |
206 | struct rtc_device *rtc = file->private_data; |
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 | |
216 | static long rtc_dev_ioctl(struct file *file, |
217 | unsigned int cmd, unsigned long arg) |
218 | { |
219 | int err = 0; |
220 | struct rtc_device *rtc = file->private_data; |
221 | const struct rtc_class_ops *ops = rtc->ops; |
222 | struct rtc_time tm; |
223 | struct rtc_wkalrm alarm; |
224 | void __user *uarg = (void __user *) arg; |
225 | |
226 | err = mutex_lock_interruptible(&rtc->ops_lock); |
227 | if (err) |
228 | return err; |
229 | |
230 | /* check that the calling task has appropriate permissions |
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)) |
238 | err = -EACCES; |
239 | break; |
240 | |
241 | case RTC_IRQP_SET: |
242 | if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) |
243 | err = -EACCES; |
244 | break; |
245 | |
246 | case RTC_PIE_ON: |
247 | if (rtc->irq_freq > rtc->max_user_freq && |
248 | !capable(CAP_SYS_RESOURCE)) |
249 | err = -EACCES; |
250 | break; |
251 | } |
252 | |
253 | if (err) |
254 | goto done; |
255 | |
256 | /* try the driver's ioctl interface */ |
257 | if (ops->ioctl) { |
258 | err = ops->ioctl(rtc->dev.parent, cmd, arg); |
259 | if (err != -ENOIOCTLCMD) { |
260 | mutex_unlock(&rtc->ops_lock); |
261 | return err; |
262 | } |
263 | } |
264 | |
265 | /* if the driver does not provide the ioctl interface |
266 | * or if that particular ioctl was not implemented |
267 | * (-ENOIOCTLCMD), we will try to emulate here. |
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. |
277 | */ |
278 | |
279 | switch (cmd) { |
280 | case RTC_ALM_READ: |
281 | mutex_unlock(&rtc->ops_lock); |
282 | |
283 | err = rtc_read_alarm(rtc, &alarm); |
284 | if (err < 0) |
285 | return err; |
286 | |
287 | if (copy_to_user(uarg, &alarm.time, sizeof(tm))) |
288 | err = -EFAULT; |
289 | return err; |
290 | |
291 | case RTC_ALM_SET: |
292 | mutex_unlock(&rtc->ops_lock); |
293 | |
294 | if (copy_from_user(&alarm.time, uarg, sizeof(tm))) |
295 | return -EFAULT; |
296 | |
297 | alarm.enabled = 0; |
298 | alarm.pending = 0; |
299 | alarm.time.tm_wday = -1; |
300 | alarm.time.tm_yday = -1; |
301 | alarm.time.tm_isdst = -1; |
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 | |
341 | return rtc_set_alarm(rtc, &alarm); |
342 | |
343 | case RTC_RD_TIME: |
344 | mutex_unlock(&rtc->ops_lock); |
345 | |
346 | err = rtc_read_time(rtc, &tm); |
347 | if (err < 0) |
348 | return err; |
349 | |
350 | if (copy_to_user(uarg, &tm, sizeof(tm))) |
351 | err = -EFAULT; |
352 | return err; |
353 | |
354 | case RTC_SET_TIME: |
355 | mutex_unlock(&rtc->ops_lock); |
356 | |
357 | if (copy_from_user(&tm, uarg, sizeof(tm))) |
358 | return -EFAULT; |
359 | |
360 | return rtc_set_time(rtc, &tm); |
361 | |
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); |
368 | break; |
369 | |
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 | |
386 | case RTC_IRQP_SET: |
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); |
392 | break; |
393 | |
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 | } |
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: |
414 | mutex_unlock(&rtc->ops_lock); |
415 | if (copy_from_user(&alarm, uarg, sizeof(alarm))) |
416 | return -EFAULT; |
417 | |
418 | return rtc_set_alarm(rtc, &alarm); |
419 | |
420 | case RTC_WKALM_RD: |
421 | mutex_unlock(&rtc->ops_lock); |
422 | err = rtc_read_alarm(rtc, &alarm); |
423 | if (err < 0) |
424 | return err; |
425 | |
426 | if (copy_to_user(uarg, &alarm, sizeof(alarm))) |
427 | err = -EFAULT; |
428 | return err; |
429 | |
430 | default: |
431 | err = -ENOTTY; |
432 | break; |
433 | } |
434 | |
435 | done: |
436 | mutex_unlock(&rtc->ops_lock); |
437 | return err; |
438 | } |
439 | |
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 | |
446 | static int rtc_dev_release(struct inode *inode, struct file *file) |
447 | { |
448 | struct rtc_device *rtc = file->private_data; |
449 | |
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 | */ |
458 | |
459 | /* Keep ioctl until all drivers are converted */ |
460 | rtc_dev_ioctl(file, RTC_UIE_OFF, 0); |
461 | rtc_update_irq_enable(rtc, 0); |
462 | rtc_irq_set_state(rtc, NULL, 0); |
463 | |
464 | if (rtc->ops->release) |
465 | rtc->ops->release(rtc->dev.parent); |
466 | |
467 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
468 | return 0; |
469 | } |
470 | |
471 | static const struct file_operations rtc_dev_fops = { |
472 | .owner = THIS_MODULE, |
473 | .llseek = no_llseek, |
474 | .read = rtc_dev_read, |
475 | .poll = rtc_dev_poll, |
476 | .unlocked_ioctl = rtc_dev_ioctl, |
477 | .open = rtc_dev_open, |
478 | .release = rtc_dev_release, |
479 | .fasync = rtc_dev_fasync, |
480 | }; |
481 | |
482 | /* insertion/removal hooks */ |
483 | |
484 | void rtc_dev_prepare(struct rtc_device *rtc) |
485 | { |
486 | if (!rtc_devt) |
487 | return; |
488 | |
489 | if (rtc->id >= RTC_DEV_MAX) { |
490 | pr_debug("%s: too many RTC devices\n", rtc->name); |
491 | return; |
492 | } |
493 | |
494 | rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id); |
495 | |
496 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
497 | INIT_WORK(&rtc->uie_task, rtc_uie_task); |
498 | setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc); |
499 | #endif |
500 | |
501 | cdev_init(&rtc->char_dev, &rtc_dev_fops); |
502 | rtc->char_dev.owner = rtc->owner; |
503 | } |
504 | |
505 | void rtc_dev_add_device(struct rtc_device *rtc) |
506 | { |
507 | if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1)) |
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, |
512 | MAJOR(rtc_devt), rtc->id); |
513 | } |
514 | |
515 | void rtc_dev_del_device(struct rtc_device *rtc) |
516 | { |
517 | if (rtc->dev.devt) |
518 | cdev_del(&rtc->char_dev); |
519 | } |
520 | |
521 | void __init rtc_dev_init(void) |
522 | { |
523 | int err; |
524 | |
525 | err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc"); |
526 | if (err < 0) |
527 | printk(KERN_ERR "%s: failed to allocate char dev region\n", |
528 | __FILE__); |
529 | } |
530 | |
531 | void __exit rtc_dev_exit(void) |
532 | { |
533 | if (rtc_devt) |
534 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); |
535 | } |
536 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9