Linux-2.6.12-rc2
[linux-3.10.git] / arch / arm / common / rtctime.c
1 /*
2  *  linux/arch/arm/common/rtctime.c
3  *
4  *  Copyright (C) 2003 Deep Blue Solutions Ltd.
5  *  Based on sa1100-rtc.c, Nils Faerber, CIH, Nicolas Pitre.
6  *  Based on rtc.c by Paul Gortmaker
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/time.h>
15 #include <linux/rtc.h>
16 #include <linux/poll.h>
17 #include <linux/proc_fs.h>
18 #include <linux/miscdevice.h>
19 #include <linux/spinlock.h>
20 #include <linux/device.h>
21
22 #include <asm/rtc.h>
23 #include <asm/semaphore.h>
24
25 static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
26 static struct fasync_struct *rtc_async_queue;
27
28 /*
29  * rtc_lock protects rtc_irq_data
30  */
31 static DEFINE_SPINLOCK(rtc_lock);
32 static unsigned long rtc_irq_data;
33
34 /*
35  * rtc_sem protects rtc_inuse and rtc_ops
36  */
37 static DECLARE_MUTEX(rtc_sem);
38 static unsigned long rtc_inuse;
39 static struct rtc_ops *rtc_ops;
40
41 #define rtc_epoch 1900UL
42
43 static const unsigned char days_in_month[] = {
44         31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
45 };
46
47 #define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
48 #define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
49
50 static int month_days(unsigned int month, unsigned int year)
51 {
52         return days_in_month[month] + (LEAP_YEAR(year) && month == 1);
53 }
54
55 /*
56  * Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
57  */
58 void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
59 {
60         int days, month, year;
61
62         days = time / 86400;
63         time -= days * 86400;
64
65         tm->tm_wday = (days + 4) % 7;
66
67         year = 1970 + days / 365;
68         days -= (year - 1970) * 365
69                 + LEAPS_THRU_END_OF(year - 1)
70                 - LEAPS_THRU_END_OF(1970 - 1);
71         if (days < 0) {
72                 year -= 1;
73                 days += 365 + LEAP_YEAR(year);
74         }
75         tm->tm_year = year - 1900;
76         tm->tm_yday = days + 1;
77
78         for (month = 0; month < 11; month++) {
79                 int newdays;
80
81                 newdays = days - month_days(month, year);
82                 if (newdays < 0)
83                         break;
84                 days = newdays;
85         }
86         tm->tm_mon = month;
87         tm->tm_mday = days + 1;
88
89         tm->tm_hour = time / 3600;
90         time -= tm->tm_hour * 3600;
91         tm->tm_min = time / 60;
92         tm->tm_sec = time - tm->tm_min * 60;
93 }
94 EXPORT_SYMBOL(rtc_time_to_tm);
95
96 /*
97  * Does the rtc_time represent a valid date/time?
98  */
99 int rtc_valid_tm(struct rtc_time *tm)
100 {
101         if (tm->tm_year < 70 ||
102             tm->tm_mon >= 12 ||
103             tm->tm_mday < 1 ||
104             tm->tm_mday > month_days(tm->tm_mon, tm->tm_year + 1900) ||
105             tm->tm_hour >= 24 ||
106             tm->tm_min >= 60 ||
107             tm->tm_sec >= 60)
108                 return -EINVAL;
109
110         return 0;
111 }
112 EXPORT_SYMBOL(rtc_valid_tm);
113
114 /*
115  * Convert Gregorian date to seconds since 01-01-1970 00:00:00.
116  */
117 int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
118 {
119         *time = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
120                        tm->tm_hour, tm->tm_min, tm->tm_sec);
121
122         return 0;
123 }
124 EXPORT_SYMBOL(rtc_tm_to_time);
125
126 /*
127  * Calculate the next alarm time given the requested alarm time mask
128  * and the current time.
129  *
130  * FIXME: for now, we just copy the alarm time because we're lazy (and
131  * is therefore buggy - setting a 10am alarm at 8pm will not result in
132  * the alarm triggering.)
133  */
134 void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm)
135 {
136         next->tm_year = now->tm_year;
137         next->tm_mon = now->tm_mon;
138         next->tm_mday = now->tm_mday;
139         next->tm_hour = alrm->tm_hour;
140         next->tm_min = alrm->tm_min;
141         next->tm_sec = alrm->tm_sec;
142 }
143
144 static inline void rtc_read_time(struct rtc_ops *ops, struct rtc_time *tm)
145 {
146         memset(tm, 0, sizeof(struct rtc_time));
147         ops->read_time(tm);
148 }
149
150 static inline int rtc_set_time(struct rtc_ops *ops, struct rtc_time *tm)
151 {
152         int ret;
153
154         ret = rtc_valid_tm(tm);
155         if (ret == 0)
156                 ret = ops->set_time(tm);
157
158         return ret;
159 }
160
161 static inline int rtc_read_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
162 {
163         int ret = -EINVAL;
164         if (ops->read_alarm) {
165                 memset(alrm, 0, sizeof(struct rtc_wkalrm));
166                 ops->read_alarm(alrm);
167                 ret = 0;
168         }
169         return ret;
170 }
171
172 static inline int rtc_set_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
173 {
174         int ret = -EINVAL;
175         if (ops->set_alarm)
176                 ret = ops->set_alarm(alrm);
177         return ret;
178 }
179
180 void rtc_update(unsigned long num, unsigned long events)
181 {
182         spin_lock(&rtc_lock);
183         rtc_irq_data = (rtc_irq_data + (num << 8)) | events;
184         spin_unlock(&rtc_lock);
185
186         wake_up_interruptible(&rtc_wait);
187         kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
188 }
189 EXPORT_SYMBOL(rtc_update);
190
191
192 static ssize_t
193 rtc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
194 {
195         DECLARE_WAITQUEUE(wait, current);
196         unsigned long data;
197         ssize_t ret;
198
199         if (count < sizeof(unsigned long))
200                 return -EINVAL;
201
202         add_wait_queue(&rtc_wait, &wait);
203         do {
204                 __set_current_state(TASK_INTERRUPTIBLE);
205
206                 spin_lock_irq(&rtc_lock);
207                 data = rtc_irq_data;
208                 rtc_irq_data = 0;
209                 spin_unlock_irq(&rtc_lock);
210
211                 if (data != 0) {
212                         ret = 0;
213                         break;
214                 }
215                 if (file->f_flags & O_NONBLOCK) {
216                         ret = -EAGAIN;
217                         break;
218                 }
219                 if (signal_pending(current)) {
220                         ret = -ERESTARTSYS;
221                         break;
222                 }
223                 schedule();
224         } while (1);
225         set_current_state(TASK_RUNNING);
226         remove_wait_queue(&rtc_wait, &wait);
227
228         if (ret == 0) {
229                 ret = put_user(data, (unsigned long __user *)buf);
230                 if (ret == 0)
231                         ret = sizeof(unsigned long);
232         }
233         return ret;
234 }
235
236 static unsigned int rtc_poll(struct file *file, poll_table *wait)
237 {
238         unsigned long data;
239
240         poll_wait(file, &rtc_wait, wait);
241
242         spin_lock_irq(&rtc_lock);
243         data = rtc_irq_data;
244         spin_unlock_irq(&rtc_lock);
245
246         return data != 0 ? POLLIN | POLLRDNORM : 0;
247 }
248
249 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
250                      unsigned long arg)
251 {
252         struct rtc_ops *ops = file->private_data;
253         struct rtc_time tm;
254         struct rtc_wkalrm alrm;
255         void __user *uarg = (void __user *)arg;
256         int ret = -EINVAL;
257
258         switch (cmd) {
259         case RTC_ALM_READ:
260                 ret = rtc_read_alarm(ops, &alrm);
261                 if (ret)
262                         break;
263                 ret = copy_to_user(uarg, &alrm.time, sizeof(tm));
264                 if (ret)
265                         ret = -EFAULT;
266                 break;
267
268         case RTC_ALM_SET:
269                 ret = copy_from_user(&alrm.time, uarg, sizeof(tm));
270                 if (ret) {
271                         ret = -EFAULT;
272                         break;
273                 }
274                 alrm.enabled = 0;
275                 alrm.pending = 0;
276                 alrm.time.tm_mday = -1;
277                 alrm.time.tm_mon = -1;
278                 alrm.time.tm_year = -1;
279                 alrm.time.tm_wday = -1;
280                 alrm.time.tm_yday = -1;
281                 alrm.time.tm_isdst = -1;
282                 ret = rtc_set_alarm(ops, &alrm);
283                 break;
284
285         case RTC_RD_TIME:
286                 rtc_read_time(ops, &tm);
287                 ret = copy_to_user(uarg, &tm, sizeof(tm));
288                 if (ret)
289                         ret = -EFAULT;
290                 break;
291
292         case RTC_SET_TIME:
293                 if (!capable(CAP_SYS_TIME)) {
294                         ret = -EACCES;
295                         break;
296                 }
297                 ret = copy_from_user(&tm, uarg, sizeof(tm));
298                 if (ret) {
299                         ret = -EFAULT;
300                         break;
301                 }
302                 ret = rtc_set_time(ops, &tm);
303                 break;
304
305         case RTC_EPOCH_SET:
306 #ifndef rtc_epoch
307                 /*
308                  * There were no RTC clocks before 1900.
309                  */
310                 if (arg < 1900) {
311                         ret = -EINVAL;
312                         break;
313                 }
314                 if (!capable(CAP_SYS_TIME)) {
315                         ret = -EACCES;
316                         break;
317                 }
318                 rtc_epoch = arg;
319                 ret = 0;
320 #endif
321                 break;
322
323         case RTC_EPOCH_READ:
324                 ret = put_user(rtc_epoch, (unsigned long __user *)uarg);
325                 break;
326
327         case RTC_WKALM_SET:
328                 ret = copy_from_user(&alrm, uarg, sizeof(alrm));
329                 if (ret) {
330                         ret = -EFAULT;
331                         break;
332                 }
333                 ret = rtc_set_alarm(ops, &alrm);
334                 break;
335
336         case RTC_WKALM_RD:
337                 ret = rtc_read_alarm(ops, &alrm);
338                 if (ret)
339                         break;
340                 ret = copy_to_user(uarg, &alrm, sizeof(alrm));
341                 if (ret)
342                         ret = -EFAULT;
343                 break;
344
345         default:
346                 if (ops->ioctl)
347                         ret = ops->ioctl(cmd, arg);
348                 break;
349         }
350         return ret;
351 }
352
353 static int rtc_open(struct inode *inode, struct file *file)
354 {
355         int ret;
356
357         down(&rtc_sem);
358
359         if (rtc_inuse) {
360                 ret = -EBUSY;
361         } else if (!rtc_ops || !try_module_get(rtc_ops->owner)) {
362                 ret = -ENODEV;
363         } else {
364                 file->private_data = rtc_ops;
365
366                 ret = rtc_ops->open ? rtc_ops->open() : 0;
367                 if (ret == 0) {
368                         spin_lock_irq(&rtc_lock);
369                         rtc_irq_data = 0;
370                         spin_unlock_irq(&rtc_lock);
371
372                         rtc_inuse = 1;
373                 }
374         }
375         up(&rtc_sem);
376
377         return ret;
378 }
379
380 static int rtc_release(struct inode *inode, struct file *file)
381 {
382         struct rtc_ops *ops = file->private_data;
383
384         if (ops->release)
385                 ops->release();
386
387         spin_lock_irq(&rtc_lock);
388         rtc_irq_data = 0;
389         spin_unlock_irq(&rtc_lock);
390
391         module_put(rtc_ops->owner);
392         rtc_inuse = 0;
393
394         return 0;
395 }
396
397 static int rtc_fasync(int fd, struct file *file, int on)
398 {
399         return fasync_helper(fd, file, on, &rtc_async_queue);
400 }
401
402 static struct file_operations rtc_fops = {
403         .owner          = THIS_MODULE,
404         .llseek         = no_llseek,
405         .read           = rtc_read,
406         .poll           = rtc_poll,
407         .ioctl          = rtc_ioctl,
408         .open           = rtc_open,
409         .release        = rtc_release,
410         .fasync         = rtc_fasync,
411 };
412
413 static struct miscdevice rtc_miscdev = {
414         .minor          = RTC_MINOR,
415         .name           = "rtc",
416         .fops           = &rtc_fops,
417 };
418
419
420 static int rtc_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)
421 {
422         struct rtc_ops *ops = data;
423         struct rtc_wkalrm alrm;
424         struct rtc_time tm;
425         char *p = page;
426
427         rtc_read_time(ops, &tm);
428
429         p += sprintf(p,
430                 "rtc_time\t: %02d:%02d:%02d\n"
431                 "rtc_date\t: %04d-%02d-%02d\n"
432                 "rtc_epoch\t: %04lu\n",
433                 tm.tm_hour, tm.tm_min, tm.tm_sec,
434                 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
435                 rtc_epoch);
436
437         if (rtc_read_alarm(ops, &alrm) == 0) {
438                 p += sprintf(p, "alrm_time\t: ");
439                 if ((unsigned int)alrm.time.tm_hour <= 24)
440                         p += sprintf(p, "%02d:", alrm.time.tm_hour);
441                 else
442                         p += sprintf(p, "**:");
443                 if ((unsigned int)alrm.time.tm_min <= 59)
444                         p += sprintf(p, "%02d:", alrm.time.tm_min);
445                 else
446                         p += sprintf(p, "**:");
447                 if ((unsigned int)alrm.time.tm_sec <= 59)
448                         p += sprintf(p, "%02d\n", alrm.time.tm_sec);
449                 else
450                         p += sprintf(p, "**\n");
451
452                 p += sprintf(p, "alrm_date\t: ");
453                 if ((unsigned int)alrm.time.tm_year <= 200)
454                         p += sprintf(p, "%04d-", alrm.time.tm_year + 1900);
455                 else
456                         p += sprintf(p, "****-");
457                 if ((unsigned int)alrm.time.tm_mon <= 11)
458                         p += sprintf(p, "%02d-", alrm.time.tm_mon + 1);
459                 else
460                         p += sprintf(p, "**-");
461                 if ((unsigned int)alrm.time.tm_mday <= 31)
462                         p += sprintf(p, "%02d\n", alrm.time.tm_mday);
463                 else
464                         p += sprintf(p, "**\n");
465                 p += sprintf(p, "alrm_wakeup\t: %s\n",
466                              alrm.enabled ? "yes" : "no");
467                 p += sprintf(p, "alrm_pending\t: %s\n",
468                              alrm.pending ? "yes" : "no");
469         }
470
471         if (ops->proc)
472                 p += ops->proc(p);
473
474         return p - page;
475 }
476
477 int register_rtc(struct rtc_ops *ops)
478 {
479         int ret = -EBUSY;
480
481         down(&rtc_sem);
482         if (rtc_ops == NULL) {
483                 rtc_ops = ops;
484
485                 ret = misc_register(&rtc_miscdev);
486                 if (ret == 0)
487                         create_proc_read_entry("driver/rtc", 0, NULL,
488                                                rtc_read_proc, ops);
489         }
490         up(&rtc_sem);
491
492         return ret;
493 }
494 EXPORT_SYMBOL(register_rtc);
495
496 void unregister_rtc(struct rtc_ops *rtc)
497 {
498         down(&rtc_sem);
499         if (rtc == rtc_ops) {
500                 remove_proc_entry("driver/rtc", NULL);
501                 misc_deregister(&rtc_miscdev);
502                 rtc_ops = NULL;
503         }
504         up(&rtc_sem);
505 }
506 EXPORT_SYMBOL(unregister_rtc);