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