2 * linux/arch/arm/common/rtctime.c
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
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.
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>
23 #include <asm/semaphore.h>
25 static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
26 static struct fasync_struct *rtc_async_queue;
29 * rtc_lock protects rtc_irq_data
31 static spinlock_t rtc_lock = SPIN_LOCK_UNLOCKED;
32 static unsigned long rtc_irq_data;
35 * rtc_sem protects rtc_inuse and rtc_ops
37 static DECLARE_MUTEX(rtc_sem);
38 static unsigned long rtc_inuse;
39 static struct rtc_ops *rtc_ops;
41 #define rtc_epoch 1900UL
43 static const unsigned char days_in_month[] = {
44 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
47 #define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
48 #define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
50 static int month_days(unsigned int month, unsigned int year)
52 return days_in_month[month] + (LEAP_YEAR(year) && month == 1);
56 * Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
58 void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
60 int days, month, year;
65 tm->tm_wday = (days + 4) % 7;
67 year = 1970 + days / 365;
68 days -= (year - 1970) * 365
69 + LEAPS_THRU_END_OF(year - 1)
70 - LEAPS_THRU_END_OF(1970 - 1);
73 days += 365 + LEAP_YEAR(year);
75 tm->tm_year = year - 1900;
76 tm->tm_yday = days + 1;
78 for (month = 0; month < 11; month++) {
81 newdays = days - month_days(month, year);
87 tm->tm_mday = days + 1;
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;
94 EXPORT_SYMBOL(rtc_time_to_tm);
97 * Convert Gregorian date to seconds since 01-01-1970 00:00:00.
99 int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
101 unsigned int yrs = tm->tm_year + 1900;
108 tm->tm_mday > month_days(tm->tm_mon, yrs) ||
114 *time = mktime(yrs, tm->tm_mon + 1, tm->tm_mday,
115 tm->tm_hour, tm->tm_min, tm->tm_sec);
119 EXPORT_SYMBOL(rtc_tm_to_time);
122 * Calculate the next alarm time given the requested alarm time mask
123 * and the current time.
125 * FIXME: for now, we just copy the alarm time because we're lazy (and
126 * is therefore buggy - setting a 10am alarm at 8pm will not result in
127 * the alarm triggering.)
129 void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm)
131 next->tm_year = now->tm_year;
132 next->tm_mon = now->tm_mon;
133 next->tm_mday = now->tm_mday;
134 next->tm_hour = alrm->tm_hour;
135 next->tm_min = alrm->tm_min;
136 next->tm_sec = alrm->tm_sec;
139 static inline void rtc_read_time(struct rtc_ops *ops, struct rtc_time *tm)
141 memset(tm, 0, sizeof(struct rtc_time));
145 static inline int rtc_set_time(struct rtc_ops *ops, struct rtc_time *tm)
147 return ops->set_time(tm);
150 static inline int rtc_read_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
153 if (ops->read_alarm) {
154 memset(alrm, 0, sizeof(struct rtc_wkalrm));
155 ops->read_alarm(alrm);
161 static inline int rtc_set_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
165 ret = ops->set_alarm(alrm);
169 void rtc_update(unsigned long num, unsigned long events)
171 spin_lock(&rtc_lock);
172 rtc_irq_data = (rtc_irq_data + (num << 8)) | events;
173 spin_unlock(&rtc_lock);
175 wake_up_interruptible(&rtc_wait);
176 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
178 EXPORT_SYMBOL(rtc_update);
182 rtc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
184 DECLARE_WAITQUEUE(wait, current);
188 if (count < sizeof(unsigned long))
191 add_wait_queue(&rtc_wait, &wait);
193 __set_current_state(TASK_INTERRUPTIBLE);
195 spin_lock_irq(&rtc_lock);
198 spin_unlock_irq(&rtc_lock);
204 if (file->f_flags & O_NONBLOCK) {
208 if (signal_pending(current)) {
214 set_current_state(TASK_RUNNING);
215 remove_wait_queue(&rtc_wait, &wait);
218 ret = put_user(data, (unsigned long __user *)buf);
220 ret = sizeof(unsigned long);
225 static unsigned int rtc_poll(struct file *file, poll_table *wait)
229 poll_wait(file, &rtc_wait, wait);
231 spin_lock_irq(&rtc_lock);
233 spin_unlock_irq(&rtc_lock);
235 return data != 0 ? POLLIN | POLLRDNORM : 0;
238 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
241 struct rtc_ops *ops = file->private_data;
243 struct rtc_wkalrm alrm;
244 void __user *uarg = (void __user *)arg;
249 ret = rtc_read_alarm(ops, &alrm);
252 ret = copy_to_user(uarg, &alrm.time, sizeof(tm));
258 ret = copy_from_user(&alrm.time, uarg, sizeof(tm));
265 alrm.time.tm_mday = -1;
266 alrm.time.tm_mon = -1;
267 alrm.time.tm_year = -1;
268 alrm.time.tm_wday = -1;
269 alrm.time.tm_yday = -1;
270 alrm.time.tm_isdst = -1;
271 ret = rtc_set_alarm(ops, &alrm);
275 rtc_read_time(ops, &tm);
276 ret = copy_to_user(uarg, &tm, sizeof(tm));
282 if (!capable(CAP_SYS_TIME)) {
286 ret = copy_from_user(&tm, uarg, sizeof(tm));
291 ret = rtc_set_time(ops, &tm);
297 * There were no RTC clocks before 1900.
303 if (!capable(CAP_SYS_TIME)) {
313 ret = put_user(rtc_epoch, (unsigned long __user *)uarg);
317 ret = copy_from_user(&alrm, uarg, sizeof(alrm));
322 ret = rtc_set_alarm(ops, &alrm);
326 ret = rtc_read_alarm(ops, &alrm);
329 ret = copy_to_user(uarg, &alrm, sizeof(alrm));
336 ret = ops->ioctl(cmd, arg);
342 static int rtc_open(struct inode *inode, struct file *file)
350 } else if (!rtc_ops || !try_module_get(rtc_ops->owner)) {
353 file->private_data = rtc_ops;
355 ret = rtc_ops->open ? rtc_ops->open() : 0;
357 spin_lock_irq(&rtc_lock);
359 spin_unlock_irq(&rtc_lock);
369 static int rtc_release(struct inode *inode, struct file *file)
371 struct rtc_ops *ops = file->private_data;
376 spin_lock_irq(&rtc_lock);
378 spin_unlock_irq(&rtc_lock);
380 module_put(rtc_ops->owner);
386 static int rtc_fasync(int fd, struct file *file, int on)
388 return fasync_helper(fd, file, on, &rtc_async_queue);
391 static struct file_operations rtc_fops = {
392 .owner = THIS_MODULE,
398 .release = rtc_release,
399 .fasync = rtc_fasync,
402 static struct miscdevice rtc_miscdev = {
409 static int rtc_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)
411 struct rtc_ops *ops = data;
412 struct rtc_wkalrm alrm;
417 rtc_read_time(ops, &tm);
420 "rtc_time\t: %02d:%02d:%02d\n"
421 "rtc_date\t: %04d-%02d-%02d\n"
422 "rtc_epoch\t: %04lu\n",
423 tm.tm_hour, tm.tm_min, tm.tm_sec,
424 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
427 if (rtc_read_alarm(ops, &alrm) == 0) {
428 p += sprintf(p, "alrm_time\t: ");
429 if ((unsigned int)alrm.time.tm_hour <= 24)
430 p += sprintf(p, "%02d:", alrm.time.tm_hour);
432 p += sprintf(p, "**:");
433 if ((unsigned int)alrm.time.tm_min <= 59)
434 p += sprintf(p, "%02d:", alrm.time.tm_min);
436 p += sprintf(p, "**:");
437 if ((unsigned int)alrm.time.tm_sec <= 59)
438 p += sprintf(p, "%02d\n", alrm.time.tm_sec);
440 p += sprintf(p, "**\n");
442 p += sprintf(p, "alrm_date\t: ");
443 if ((unsigned int)alrm.time.tm_year <= 200)
444 p += sprintf(p, "%04d-", alrm.time.tm_year + 1900);
446 p += sprintf(p, "****-");
447 if ((unsigned int)alrm.time.tm_mon <= 11)
448 p += sprintf(p, "%02d-", alrm.time.tm_mon + 1);
450 p += sprintf(p, "**-");
451 if ((unsigned int)alrm.time.tm_mday <= 31)
452 p += sprintf(p, "%02d\n", alrm.time.tm_mday);
454 p += sprintf(p, "**\n");
455 p += sprintf(p, "alrm_wakeup\t: %s\n",
456 alrm.enabled ? "yes" : "no");
457 p += sprintf(p, "alrm_pending\t: %s\n",
458 alrm.pending ? "yes" : "no");
464 len = (p - page) - off;
473 int register_rtc(struct rtc_ops *ops)
478 if (rtc_ops == NULL) {
481 ret = misc_register(&rtc_miscdev);
483 create_proc_read_entry("driver/rtc", 0, NULL,
490 EXPORT_SYMBOL(register_rtc);
492 void unregister_rtc(struct rtc_ops *rtc)
495 if (rtc == rtc_ops) {
496 remove_proc_entry("driver/rtc", NULL);
497 misc_deregister(&rtc_miscdev);
502 EXPORT_SYMBOL(unregister_rtc);