Merge branch 'upstream'
[linux-2.6] / 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/capability.h>
21 #include <linux/device.h>
22 #include <linux/mutex.h>
23 #include <linux/rtc.h>
24
25 #include <asm/rtc.h>
26 #include <asm/semaphore.h>
27
28 static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
29 static struct fasync_struct *rtc_async_queue;
30
31 /*
32  * rtc_lock protects rtc_irq_data
33  */
34 static DEFINE_SPINLOCK(rtc_lock);
35 static unsigned long rtc_irq_data;
36
37 /*
38  * rtc_sem protects rtc_inuse and rtc_ops
39  */
40 static DEFINE_MUTEX(rtc_mutex);
41 static unsigned long rtc_inuse;
42 static struct rtc_ops *rtc_ops;
43
44 #define rtc_epoch 1900UL
45
46 /*
47  * Calculate the next alarm time given the requested alarm time mask
48  * and the current time.
49  */
50 void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm)
51 {
52         unsigned long next_time;
53         unsigned long now_time;
54
55         next->tm_year = now->tm_year;
56         next->tm_mon = now->tm_mon;
57         next->tm_mday = now->tm_mday;
58         next->tm_hour = alrm->tm_hour;
59         next->tm_min = alrm->tm_min;
60         next->tm_sec = alrm->tm_sec;
61
62         rtc_tm_to_time(now, &now_time);
63         rtc_tm_to_time(next, &next_time);
64
65         if (next_time < now_time) {
66                 /* Advance one day */
67                 next_time += 60 * 60 * 24;
68                 rtc_time_to_tm(next_time, next);
69         }
70 }
71
72 static inline int rtc_arm_read_time(struct rtc_ops *ops, struct rtc_time *tm)
73 {
74         memset(tm, 0, sizeof(struct rtc_time));
75         return ops->read_time(tm);
76 }
77
78 static inline int rtc_arm_set_time(struct rtc_ops *ops, struct rtc_time *tm)
79 {
80         int ret;
81
82         ret = rtc_valid_tm(tm);
83         if (ret == 0)
84                 ret = ops->set_time(tm);
85
86         return ret;
87 }
88
89 static inline int rtc_arm_read_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
90 {
91         int ret = -EINVAL;
92         if (ops->read_alarm) {
93                 memset(alrm, 0, sizeof(struct rtc_wkalrm));
94                 ret = ops->read_alarm(alrm);
95         }
96         return ret;
97 }
98
99 static inline int rtc_arm_set_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
100 {
101         int ret = -EINVAL;
102         if (ops->set_alarm)
103                 ret = ops->set_alarm(alrm);
104         return ret;
105 }
106
107 void rtc_update(unsigned long num, unsigned long events)
108 {
109         spin_lock(&rtc_lock);
110         rtc_irq_data = (rtc_irq_data + (num << 8)) | events;
111         spin_unlock(&rtc_lock);
112
113         wake_up_interruptible(&rtc_wait);
114         kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
115 }
116 EXPORT_SYMBOL(rtc_update);
117
118
119 static ssize_t
120 rtc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
121 {
122         DECLARE_WAITQUEUE(wait, current);
123         unsigned long data;
124         ssize_t ret;
125
126         if (count < sizeof(unsigned long))
127                 return -EINVAL;
128
129         add_wait_queue(&rtc_wait, &wait);
130         do {
131                 __set_current_state(TASK_INTERRUPTIBLE);
132
133                 spin_lock_irq(&rtc_lock);
134                 data = rtc_irq_data;
135                 rtc_irq_data = 0;
136                 spin_unlock_irq(&rtc_lock);
137
138                 if (data != 0) {
139                         ret = 0;
140                         break;
141                 }
142                 if (file->f_flags & O_NONBLOCK) {
143                         ret = -EAGAIN;
144                         break;
145                 }
146                 if (signal_pending(current)) {
147                         ret = -ERESTARTSYS;
148                         break;
149                 }
150                 schedule();
151         } while (1);
152         set_current_state(TASK_RUNNING);
153         remove_wait_queue(&rtc_wait, &wait);
154
155         if (ret == 0) {
156                 ret = put_user(data, (unsigned long __user *)buf);
157                 if (ret == 0)
158                         ret = sizeof(unsigned long);
159         }
160         return ret;
161 }
162
163 static unsigned int rtc_poll(struct file *file, poll_table *wait)
164 {
165         unsigned long data;
166
167         poll_wait(file, &rtc_wait, wait);
168
169         spin_lock_irq(&rtc_lock);
170         data = rtc_irq_data;
171         spin_unlock_irq(&rtc_lock);
172
173         return data != 0 ? POLLIN | POLLRDNORM : 0;
174 }
175
176 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
177                      unsigned long arg)
178 {
179         struct rtc_ops *ops = file->private_data;
180         struct rtc_time tm;
181         struct rtc_wkalrm alrm;
182         void __user *uarg = (void __user *)arg;
183         int ret = -EINVAL;
184
185         switch (cmd) {
186         case RTC_ALM_READ:
187                 ret = rtc_arm_read_alarm(ops, &alrm);
188                 if (ret)
189                         break;
190                 ret = copy_to_user(uarg, &alrm.time, sizeof(tm));
191                 if (ret)
192                         ret = -EFAULT;
193                 break;
194
195         case RTC_ALM_SET:
196                 ret = copy_from_user(&alrm.time, uarg, sizeof(tm));
197                 if (ret) {
198                         ret = -EFAULT;
199                         break;
200                 }
201                 alrm.enabled = 0;
202                 alrm.pending = 0;
203                 alrm.time.tm_mday = -1;
204                 alrm.time.tm_mon = -1;
205                 alrm.time.tm_year = -1;
206                 alrm.time.tm_wday = -1;
207                 alrm.time.tm_yday = -1;
208                 alrm.time.tm_isdst = -1;
209                 ret = rtc_arm_set_alarm(ops, &alrm);
210                 break;
211
212         case RTC_RD_TIME:
213                 ret = rtc_arm_read_time(ops, &tm);
214                 if (ret)
215                         break;
216                 ret = copy_to_user(uarg, &tm, sizeof(tm));
217                 if (ret)
218                         ret = -EFAULT;
219                 break;
220
221         case RTC_SET_TIME:
222                 if (!capable(CAP_SYS_TIME)) {
223                         ret = -EACCES;
224                         break;
225                 }
226                 ret = copy_from_user(&tm, uarg, sizeof(tm));
227                 if (ret) {
228                         ret = -EFAULT;
229                         break;
230                 }
231                 ret = rtc_arm_set_time(ops, &tm);
232                 break;
233
234         case RTC_EPOCH_SET:
235 #ifndef rtc_epoch
236                 /*
237                  * There were no RTC clocks before 1900.
238                  */
239                 if (arg < 1900) {
240                         ret = -EINVAL;
241                         break;
242                 }
243                 if (!capable(CAP_SYS_TIME)) {
244                         ret = -EACCES;
245                         break;
246                 }
247                 rtc_epoch = arg;
248                 ret = 0;
249 #endif
250                 break;
251
252         case RTC_EPOCH_READ:
253                 ret = put_user(rtc_epoch, (unsigned long __user *)uarg);
254                 break;
255
256         case RTC_WKALM_SET:
257                 ret = copy_from_user(&alrm, uarg, sizeof(alrm));
258                 if (ret) {
259                         ret = -EFAULT;
260                         break;
261                 }
262                 ret = rtc_arm_set_alarm(ops, &alrm);
263                 break;
264
265         case RTC_WKALM_RD:
266                 ret = rtc_arm_read_alarm(ops, &alrm);
267                 if (ret)
268                         break;
269                 ret = copy_to_user(uarg, &alrm, sizeof(alrm));
270                 if (ret)
271                         ret = -EFAULT;
272                 break;
273
274         default:
275                 if (ops->ioctl)
276                         ret = ops->ioctl(cmd, arg);
277                 break;
278         }
279         return ret;
280 }
281
282 static int rtc_open(struct inode *inode, struct file *file)
283 {
284         int ret;
285
286         mutex_lock(&rtc_mutex);
287
288         if (rtc_inuse) {
289                 ret = -EBUSY;
290         } else if (!rtc_ops || !try_module_get(rtc_ops->owner)) {
291                 ret = -ENODEV;
292         } else {
293                 file->private_data = rtc_ops;
294
295                 ret = rtc_ops->open ? rtc_ops->open() : 0;
296                 if (ret == 0) {
297                         spin_lock_irq(&rtc_lock);
298                         rtc_irq_data = 0;
299                         spin_unlock_irq(&rtc_lock);
300
301                         rtc_inuse = 1;
302                 }
303         }
304         mutex_unlock(&rtc_mutex);
305
306         return ret;
307 }
308
309 static int rtc_release(struct inode *inode, struct file *file)
310 {
311         struct rtc_ops *ops = file->private_data;
312
313         if (ops->release)
314                 ops->release();
315
316         spin_lock_irq(&rtc_lock);
317         rtc_irq_data = 0;
318         spin_unlock_irq(&rtc_lock);
319
320         module_put(rtc_ops->owner);
321         rtc_inuse = 0;
322
323         return 0;
324 }
325
326 static int rtc_fasync(int fd, struct file *file, int on)
327 {
328         return fasync_helper(fd, file, on, &rtc_async_queue);
329 }
330
331 static struct file_operations rtc_fops = {
332         .owner          = THIS_MODULE,
333         .llseek         = no_llseek,
334         .read           = rtc_read,
335         .poll           = rtc_poll,
336         .ioctl          = rtc_ioctl,
337         .open           = rtc_open,
338         .release        = rtc_release,
339         .fasync         = rtc_fasync,
340 };
341
342 static struct miscdevice rtc_miscdev = {
343         .minor          = RTC_MINOR,
344         .name           = "rtc",
345         .fops           = &rtc_fops,
346 };
347
348
349 static int rtc_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)
350 {
351         struct rtc_ops *ops = data;
352         struct rtc_wkalrm alrm;
353         struct rtc_time tm;
354         char *p = page;
355
356         if (rtc_arm_read_time(ops, &tm) == 0) {
357                 p += sprintf(p,
358                         "rtc_time\t: %02d:%02d:%02d\n"
359                         "rtc_date\t: %04d-%02d-%02d\n"
360                         "rtc_epoch\t: %04lu\n",
361                         tm.tm_hour, tm.tm_min, tm.tm_sec,
362                         tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
363                         rtc_epoch);
364         }
365
366         if (rtc_arm_read_alarm(ops, &alrm) == 0) {
367                 p += sprintf(p, "alrm_time\t: ");
368                 if ((unsigned int)alrm.time.tm_hour <= 24)
369                         p += sprintf(p, "%02d:", alrm.time.tm_hour);
370                 else
371                         p += sprintf(p, "**:");
372                 if ((unsigned int)alrm.time.tm_min <= 59)
373                         p += sprintf(p, "%02d:", alrm.time.tm_min);
374                 else
375                         p += sprintf(p, "**:");
376                 if ((unsigned int)alrm.time.tm_sec <= 59)
377                         p += sprintf(p, "%02d\n", alrm.time.tm_sec);
378                 else
379                         p += sprintf(p, "**\n");
380
381                 p += sprintf(p, "alrm_date\t: ");
382                 if ((unsigned int)alrm.time.tm_year <= 200)
383                         p += sprintf(p, "%04d-", alrm.time.tm_year + 1900);
384                 else
385                         p += sprintf(p, "****-");
386                 if ((unsigned int)alrm.time.tm_mon <= 11)
387                         p += sprintf(p, "%02d-", alrm.time.tm_mon + 1);
388                 else
389                         p += sprintf(p, "**-");
390                 if ((unsigned int)alrm.time.tm_mday <= 31)
391                         p += sprintf(p, "%02d\n", alrm.time.tm_mday);
392                 else
393                         p += sprintf(p, "**\n");
394                 p += sprintf(p, "alrm_wakeup\t: %s\n",
395                              alrm.enabled ? "yes" : "no");
396                 p += sprintf(p, "alrm_pending\t: %s\n",
397                              alrm.pending ? "yes" : "no");
398         }
399
400         if (ops->proc)
401                 p += ops->proc(p);
402
403         return p - page;
404 }
405
406 int register_rtc(struct rtc_ops *ops)
407 {
408         int ret = -EBUSY;
409
410         mutex_lock(&rtc_mutex);
411         if (rtc_ops == NULL) {
412                 rtc_ops = ops;
413
414                 ret = misc_register(&rtc_miscdev);
415                 if (ret == 0)
416                         create_proc_read_entry("driver/rtc", 0, NULL,
417                                                rtc_read_proc, ops);
418         }
419         mutex_unlock(&rtc_mutex);
420
421         return ret;
422 }
423 EXPORT_SYMBOL(register_rtc);
424
425 void unregister_rtc(struct rtc_ops *rtc)
426 {
427         mutex_lock(&rtc_mutex);
428         if (rtc == rtc_ops) {
429                 remove_proc_entry("driver/rtc", NULL);
430                 misc_deregister(&rtc_miscdev);
431                 rtc_ops = NULL;
432         }
433         mutex_unlock(&rtc_mutex);
434 }
435 EXPORT_SYMBOL(unregister_rtc);