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[Bluetooth] Switch from OGF+OCF to using only opcodes
[linux-2.6/verdex.git] / drivers / rtc / rtc-dev.c
blob814583bd2fe709c1da0710808ed6f4cffbe8b50f
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 /* We keep the lock as long as the device is in use
30 * and return immediately if busy
31 */
32 if (!(mutex_trylock(&rtc->char_lock)))
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, release the lock */
47 mutex_unlock(&rtc->char_lock);
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 */
56 static 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 local_irq_disable();
67 spin_lock(&rtc->irq_lock);
68 if (rtc->stop_uie_polling || err) {
69 rtc->uie_task_active = 0;
70 } else if (rtc->oldsecs != tm.tm_sec) {
71 num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
72 rtc->oldsecs = tm.tm_sec;
73 rtc->uie_timer.expires = jiffies + HZ - (HZ/10);
74 rtc->uie_timer_active = 1;
75 rtc->uie_task_active = 0;
76 add_timer(&rtc->uie_timer);
77 } else if (schedule_work(&rtc->uie_task) == 0) {
78 rtc->uie_task_active = 0;
79 }
80 spin_unlock(&rtc->irq_lock);
81 if (num)
82 rtc_update_irq(rtc, num, RTC_UF | RTC_IRQF);
83 local_irq_enable();
84 }
85 static void rtc_uie_timer(unsigned long data)
86 {
87 struct rtc_device *rtc = (struct rtc_device *)data;
88 unsigned long flags;
89
90 spin_lock_irqsave(&rtc->irq_lock, flags);
91 rtc->uie_timer_active = 0;
92 rtc->uie_task_active = 1;
93 if ((schedule_work(&rtc->uie_task) == 0))
94 rtc->uie_task_active = 0;
95 spin_unlock_irqrestore(&rtc->irq_lock, flags);
96 }
97
98 static void clear_uie(struct rtc_device *rtc)
99 {
100 spin_lock_irq(&rtc->irq_lock);
101 if (rtc->irq_active) {
102 rtc->stop_uie_polling = 1;
103 if (rtc->uie_timer_active) {
104 spin_unlock_irq(&rtc->irq_lock);
105 del_timer_sync(&rtc->uie_timer);
106 spin_lock_irq(&rtc->irq_lock);
107 rtc->uie_timer_active = 0;
108 }
109 if (rtc->uie_task_active) {
110 spin_unlock_irq(&rtc->irq_lock);
111 flush_scheduled_work();
112 spin_lock_irq(&rtc->irq_lock);
113 }
114 rtc->irq_active = 0;
115 }
116 spin_unlock_irq(&rtc->irq_lock);
117 }
118
119 static int set_uie(struct rtc_device *rtc)
120 {
121 struct rtc_time tm;
122 int err;
123
124 err = rtc_read_time(rtc, &tm);
125 if (err)
126 return err;
127 spin_lock_irq(&rtc->irq_lock);
128 if (!rtc->irq_active) {
129 rtc->irq_active = 1;
130 rtc->stop_uie_polling = 0;
131 rtc->oldsecs = tm.tm_sec;
132 rtc->uie_task_active = 1;
133 if (schedule_work(&rtc->uie_task) == 0)
134 rtc->uie_task_active = 0;
135 }
136 rtc->irq_data = 0;
137 spin_unlock_irq(&rtc->irq_lock);
138 return 0;
139 }
140 #endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
141
142 static ssize_t
143 rtc_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
197 static unsigned int 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) ? (POLLIN | POLLRDNORM) : 0;
207 }
208
209 static int rtc_dev_ioctl(struct inode *inode, 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 /* check that the calling task has appropriate permissions
220 * for certain ioctls. doing this check here is useful
221 * to avoid duplicate code in each driver.
222 */
223 switch (cmd) {
224 case RTC_EPOCH_SET:
225 case RTC_SET_TIME:
226 if (!capable(CAP_SYS_TIME))
227 return -EACCES;
228 break;
229
230 case RTC_IRQP_SET:
231 if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
232 return -EACCES;
233 break;
234
235 case RTC_PIE_ON:
236 if (rtc->irq_freq > rtc->max_user_freq &&
237 !capable(CAP_SYS_RESOURCE))
238 return -EACCES;
239 break;
240 }
241
242 /* try the driver's ioctl interface */
243 if (ops->ioctl) {
244 err = ops->ioctl(rtc->dev.parent, cmd, arg);
245 if (err != -ENOIOCTLCMD)
246 return err;
247 }
248
249 /* if the driver does not provide the ioctl interface
250 * or if that particular ioctl was not implemented
251 * (-ENOIOCTLCMD), we will try to emulate here.
252 */
253
254 switch (cmd) {
255 case RTC_ALM_READ:
256 err = rtc_read_alarm(rtc, &alarm);
257 if (err < 0)
258 return err;
259
260 if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
261 return -EFAULT;
262 break;
263
264 case RTC_ALM_SET:
265 if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
266 return -EFAULT;
267
268 alarm.enabled = 0;
269 alarm.pending = 0;
270 alarm.time.tm_wday = -1;
271 alarm.time.tm_yday = -1;
272 alarm.time.tm_isdst = -1;
273
274 /* RTC_ALM_SET alarms may be up to 24 hours in the future.
275 * Rather than expecting every RTC to implement "don't care"
276 * for day/month/year fields, just force the alarm to have
277 * the right values for those fields.
278 *
279 * RTC_WKALM_SET should be used instead. Not only does it
280 * eliminate the need for a separate RTC_AIE_ON call, it
281 * doesn't have the "alarm 23:59:59 in the future" race.
282 *
283 * NOTE: some legacy code may have used invalid fields as
284 * wildcards, exposing hardware "periodic alarm" capabilities.
285 * Not supported here.
286 */
287 {
288 unsigned long now, then;
289
290 err = rtc_read_time(rtc, &tm);
291 if (err < 0)
292 return err;
293 rtc_tm_to_time(&tm, &now);
294
295 alarm.time.tm_mday = tm.tm_mday;
296 alarm.time.tm_mon = tm.tm_mon;
297 alarm.time.tm_year = tm.tm_year;
298 err = rtc_valid_tm(&alarm.time);
299 if (err < 0)
300 return err;
301 rtc_tm_to_time(&alarm.time, &then);
302
303 /* alarm may need to wrap into tomorrow */
304 if (then < now) {
305 rtc_time_to_tm(now + 24 * 60 * 60, &tm);
306 alarm.time.tm_mday = tm.tm_mday;
307 alarm.time.tm_mon = tm.tm_mon;
308 alarm.time.tm_year = tm.tm_year;
309 }
310 }
311
312 err = rtc_set_alarm(rtc, &alarm);
313 break;
314
315 case RTC_RD_TIME:
316 err = rtc_read_time(rtc, &tm);
317 if (err < 0)
318 return err;
319
320 if (copy_to_user(uarg, &tm, sizeof(tm)))
321 return -EFAULT;
322 break;
323
324 case RTC_SET_TIME:
325 if (copy_from_user(&tm, uarg, sizeof(tm)))
326 return -EFAULT;
327
328 err = rtc_set_time(rtc, &tm);
329 break;
330
331 case RTC_PIE_ON:
332 err = rtc_irq_set_state(rtc, NULL, 1);
333 break;
334
335 case RTC_PIE_OFF:
336 err = rtc_irq_set_state(rtc, NULL, 0);
337 break;
338
339 case RTC_IRQP_SET:
340 err = rtc_irq_set_freq(rtc, NULL, arg);
341 break;
342
343 case RTC_IRQP_READ:
344 err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
345 break;
346
347 #if 0
348 case RTC_EPOCH_SET:
349 #ifndef rtc_epoch
350 /*
351 * There were no RTC clocks before 1900.
352 */
353 if (arg < 1900) {
354 err = -EINVAL;
355 break;
356 }
357 rtc_epoch = arg;
358 err = 0;
359 #endif
360 break;
361
362 case RTC_EPOCH_READ:
363 err = put_user(rtc_epoch, (unsigned long __user *)uarg);
364 break;
365 #endif
366 case RTC_WKALM_SET:
367 if (copy_from_user(&alarm, uarg, sizeof(alarm)))
368 return -EFAULT;
369
370 err = rtc_set_alarm(rtc, &alarm);
371 break;
372
373 case RTC_WKALM_RD:
374 err = rtc_read_alarm(rtc, &alarm);
375 if (err < 0)
376 return err;
377
378 if (copy_to_user(uarg, &alarm, sizeof(alarm)))
379 return -EFAULT;
380 break;
381
382 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
383 case RTC_UIE_OFF:
384 clear_uie(rtc);
385 return 0;
386
387 case RTC_UIE_ON:
388 return set_uie(rtc);
389 #endif
390 default:
391 err = -ENOTTY;
392 break;
393 }
394
395 return err;
396 }
397
398 static int rtc_dev_release(struct inode *inode, struct file *file)
399 {
400 struct rtc_device *rtc = file->private_data;
401
402 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
403 clear_uie(rtc);
404 #endif
405 if (rtc->ops->release)
406 rtc->ops->release(rtc->dev.parent);
407
408 mutex_unlock(&rtc->char_lock);
409 return 0;
410 }
411
412 static int rtc_dev_fasync(int fd, struct file *file, int on)
413 {
414 struct rtc_device *rtc = file->private_data;
415 return fasync_helper(fd, file, on, &rtc->async_queue);
416 }
417
418 static const struct file_operations rtc_dev_fops = {
419 .owner = THIS_MODULE,
420 .llseek = no_llseek,
421 .read = rtc_dev_read,
422 .poll = rtc_dev_poll,
423 .ioctl = rtc_dev_ioctl,
424 .open = rtc_dev_open,
425 .release = rtc_dev_release,
426 .fasync = rtc_dev_fasync,
427 };
428
429 /* insertion/removal hooks */
430
431 void rtc_dev_prepare(struct rtc_device *rtc)
432 {
433 if (!rtc_devt)
434 return;
435
436 if (rtc->id >= RTC_DEV_MAX) {
437 pr_debug("%s: too many RTC devices\n", rtc->name);
438 return;
439 }
440
441 rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
442
443 mutex_init(&rtc->char_lock);
444 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
445 INIT_WORK(&rtc->uie_task, rtc_uie_task);
446 setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);
447 #endif
448
449 cdev_init(&rtc->char_dev, &rtc_dev_fops);
450 rtc->char_dev.owner = rtc->owner;
451 }
452
453 void rtc_dev_add_device(struct rtc_device *rtc)
454 {
455 if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1))
456 printk(KERN_WARNING "%s: failed to add char device %d:%d\n",
457 rtc->name, MAJOR(rtc_devt), rtc->id);
458 else
459 pr_debug("%s: dev (%d:%d)\n", rtc->name,
460 MAJOR(rtc_devt), rtc->id);
461 }
462
463 void rtc_dev_del_device(struct rtc_device *rtc)
464 {
465 if (rtc->dev.devt)
466 cdev_del(&rtc->char_dev);
467 }
468
469 void __init rtc_dev_init(void)
470 {
471 int err;
472
473 err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
474 if (err < 0)
475 printk(KERN_ERR "%s: failed to allocate char dev region\n",
476 __FILE__);
477 }
478
479 void __exit rtc_dev_exit(void)
480 {
481 if (rtc_devt)
482 unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
483 }
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