blob: 0c66b802736a10540bca3ed9d7ef34f5b0208b4a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Real Time Clock interface for Linux
3 *
4 * Copyright (C) 1996 Paul Gortmaker
5 *
6 * This driver allows use of the real time clock (built into
7 * nearly all computers) from user space. It exports the /dev/rtc
8 * interface supporting various ioctl() and also the
9 * /proc/driver/rtc pseudo-file for status information.
10 *
11 * The ioctls can be used to set the interrupt behaviour and
12 * generation rate from the RTC via IRQ 8. Then the /dev/rtc
13 * interface can be used to make use of these timer interrupts,
14 * be they interval or alarm based.
15 *
16 * The /dev/rtc interface will block on reads until an interrupt
17 * has been received. If a RTC interrupt has already happened,
18 * it will output an unsigned long and then block. The output value
19 * contains the interrupt status in the low byte and the number of
20 * interrupts since the last read in the remaining high bytes. The
21 * /dev/rtc interface can also be used with the select(2) call.
22 *
23 * This program is free software; you can redistribute it and/or
24 * modify it under the terms of the GNU General Public License
25 * as published by the Free Software Foundation; either version
26 * 2 of the License, or (at your option) any later version.
27 *
28 * Based on other minimal char device drivers, like Alan's
29 * watchdog, Ted's random, etc. etc.
30 *
31 * 1.07 Paul Gortmaker.
32 * 1.08 Miquel van Smoorenburg: disallow certain things on the
33 * DEC Alpha as the CMOS clock is also used for other things.
34 * 1.09 Nikita Schmidt: epoch support and some Alpha cleanup.
35 * 1.09a Pete Zaitcev: Sun SPARC
36 * 1.09b Jeff Garzik: Modularize, init cleanup
37 * 1.09c Jeff Garzik: SMP cleanup
Ralf Baechle12a0a702006-10-09 23:20:47 +010038 * 1.10 Paul Barton-Davis: add support for async I/O
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 * 1.10a Andrea Arcangeli: Alpha updates
40 * 1.10b Andrew Morton: SMP lock fix
41 * 1.10c Cesar Barros: SMP locking fixes and cleanup
42 * 1.10d Paul Gortmaker: delete paranoia check in rtc_exit
43 * 1.10e Maciej W. Rozycki: Handle DECstation's year weirdness.
Ralf Baechle12a0a702006-10-09 23:20:47 +010044 * 1.11 Takashi Iwai: Kernel access functions
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 * rtc_register/rtc_unregister/rtc_control
46 * 1.11a Daniele Bellucci: Audit create_proc_read_entry in rtc_init
47 * 1.12 Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
48 * CONFIG_HPET_EMULATE_RTC
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -070049 * 1.12a Maciej W. Rozycki: Handle memory-mapped chips properly.
Alan Coxb7599582006-01-11 12:17:32 -080050 * 1.12ac Alan Cox: Allow read access to the day of week register
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 */
52
Alan Coxb7599582006-01-11 12:17:32 -080053#define RTC_VERSION "1.12ac"
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
Linus Torvalds1da177e2005-04-16 15:20:36 -070055/*
56 * Note that *all* calls to CMOS_READ and CMOS_WRITE are done with
57 * interrupts disabled. Due to the index-port/data-port (0x70/0x71)
58 * design of the RTC, we don't want two different things trying to
59 * get to it at once. (e.g. the periodic 11 min sync from time.c vs.
60 * this driver.)
61 */
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063#include <linux/interrupt.h>
64#include <linux/module.h>
65#include <linux/kernel.h>
66#include <linux/types.h>
67#include <linux/miscdevice.h>
68#include <linux/ioport.h>
69#include <linux/fcntl.h>
70#include <linux/mc146818rtc.h>
71#include <linux/init.h>
72#include <linux/poll.h>
73#include <linux/proc_fs.h>
74#include <linux/seq_file.h>
75#include <linux/spinlock.h>
76#include <linux/sysctl.h>
77#include <linux/wait.h>
78#include <linux/bcd.h>
Luca Falavigna47f176f2005-06-28 20:44:42 -070079#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81#include <asm/current.h>
82#include <asm/uaccess.h>
83#include <asm/system.h>
84
Chris Wright55f93af2007-07-21 17:10:09 +020085#ifdef CONFIG_X86
Linus Torvalds1da177e2005-04-16 15:20:36 -070086#include <asm/hpet.h>
87#endif
88
David S. Millercdee99d2007-07-19 13:59:58 -070089#ifdef CONFIG_SPARC32
Linus Torvalds1da177e2005-04-16 15:20:36 -070090#include <linux/pci.h>
91#include <asm/ebus.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93static unsigned long rtc_port;
94static int rtc_irq = PCI_IRQ_NONE;
95#endif
96
97#ifdef CONFIG_HPET_RTC_IRQ
98#undef RTC_IRQ
99#endif
100
101#ifdef RTC_IRQ
102static int rtc_has_irq = 1;
103#endif
104
105#ifndef CONFIG_HPET_EMULATE_RTC
106#define is_hpet_enabled() 0
107#define hpet_set_alarm_time(hrs, min, sec) 0
108#define hpet_set_periodic_freq(arg) 0
109#define hpet_mask_rtc_irq_bit(arg) 0
110#define hpet_set_rtc_irq_bit(arg) 0
111#define hpet_rtc_timer_init() do { } while (0)
112#define hpet_rtc_dropped_irq() 0
Andrew Morton533ffc22006-12-22 01:06:36 -0800113#ifdef RTC_IRQ
114static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
115{
116 return 0;
117}
118#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119#else
David Howells7d12e782006-10-05 14:55:46 +0100120extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121#endif
122
123/*
124 * We sponge a minor off of the misc major. No need slurping
125 * up another valuable major dev number for this. If you add
126 * an ioctl, make sure you don't conflict with SPARC's RTC
127 * ioctls.
128 */
129
130static struct fasync_struct *rtc_async_queue;
131
132static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
133
134#ifdef RTC_IRQ
Jiri Slaby40565f12007-02-12 00:52:31 -0800135static void rtc_dropped_irq(unsigned long data);
136
137static DEFINE_TIMER(rtc_irq_timer, rtc_dropped_irq, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138#endif
139
140static ssize_t rtc_read(struct file *file, char __user *buf,
141 size_t count, loff_t *ppos);
142
143static int rtc_ioctl(struct inode *inode, struct file *file,
144 unsigned int cmd, unsigned long arg);
145
146#ifdef RTC_IRQ
147static unsigned int rtc_poll(struct file *file, poll_table *wait);
148#endif
149
150static void get_rtc_alm_time (struct rtc_time *alm_tm);
151#ifdef RTC_IRQ
Takashi Iwaic3348762005-11-07 11:14:57 +0100152static void set_rtc_irq_bit_locked(unsigned char bit);
153static void mask_rtc_irq_bit_locked(unsigned char bit);
154
155static inline void set_rtc_irq_bit(unsigned char bit)
156{
157 spin_lock_irq(&rtc_lock);
158 set_rtc_irq_bit_locked(bit);
159 spin_unlock_irq(&rtc_lock);
160}
161
162static void mask_rtc_irq_bit(unsigned char bit)
163{
164 spin_lock_irq(&rtc_lock);
165 mask_rtc_irq_bit_locked(bit);
166 spin_unlock_irq(&rtc_lock);
167}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168#endif
169
Jan Beulich9cef7792006-12-13 00:35:05 -0800170#ifdef CONFIG_PROC_FS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171static int rtc_proc_open(struct inode *inode, struct file *file);
Jan Beulich9cef7792006-12-13 00:35:05 -0800172#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
174/*
175 * Bits in rtc_status. (6 bits of room for future expansion)
176 */
177
178#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
179#define RTC_TIMER_ON 0x02 /* missed irq timer active */
180
181/*
182 * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is
183 * protected by the big kernel lock. However, ioctl can still disable the timer
184 * in rtc_status and then with del_timer after the interrupt has read
185 * rtc_status but before mod_timer is called, which would then reenable the
186 * timer (but you would need to have an awful timing before you'd trip on it)
187 */
188static unsigned long rtc_status = 0; /* bitmapped status byte. */
189static unsigned long rtc_freq = 0; /* Current periodic IRQ rate */
190static unsigned long rtc_irq_data = 0; /* our output to the world */
191static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */
192
193#ifdef RTC_IRQ
194/*
195 * rtc_task_lock nests inside rtc_lock.
196 */
197static DEFINE_SPINLOCK(rtc_task_lock);
198static rtc_task_t *rtc_callback = NULL;
199#endif
200
201/*
202 * If this driver ever becomes modularised, it will be really nice
203 * to make the epoch retain its value across module reload...
204 */
205
206static unsigned long epoch = 1900; /* year corresponding to 0x00 */
207
208static const unsigned char days_in_mo[] =
209{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
210
211/*
212 * Returns true if a clock update is in progress
213 */
214static inline unsigned char rtc_is_updating(void)
215{
Peter Zijlstra0b16f212006-09-25 16:24:23 -0700216 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 unsigned char uip;
218
Peter Zijlstra0b16f212006-09-25 16:24:23 -0700219 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
Peter Zijlstra0b16f212006-09-25 16:24:23 -0700221 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 return uip;
223}
224
225#ifdef RTC_IRQ
226/*
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -0700227 * A very tiny interrupt handler. It runs with IRQF_DISABLED set,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 * but there is possibility of conflicting with the set_rtc_mmss()
229 * call (the rtc irq and the timer irq can easily run at the same
230 * time in two different CPUs). So we need to serialize
231 * accesses to the chip with the rtc_lock spinlock that each
232 * architecture should implement in the timer code.
233 * (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.)
234 */
235
David Howells7d12e782006-10-05 14:55:46 +0100236irqreturn_t rtc_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237{
238 /*
239 * Can be an alarm interrupt, update complete interrupt,
240 * or a periodic interrupt. We store the status in the
241 * low byte and the number of interrupts received since
242 * the last read in the remainder of rtc_irq_data.
243 */
244
245 spin_lock (&rtc_lock);
246 rtc_irq_data += 0x100;
247 rtc_irq_data &= ~0xff;
248 if (is_hpet_enabled()) {
249 /*
250 * In this case it is HPET RTC interrupt handler
251 * calling us, with the interrupt information
252 * passed as arg1, instead of irq.
253 */
254 rtc_irq_data |= (unsigned long)irq & 0xF0;
255 } else {
256 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0);
257 }
258
259 if (rtc_status & RTC_TIMER_ON)
260 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
261
262 spin_unlock (&rtc_lock);
263
264 /* Now do the rest of the actions */
265 spin_lock(&rtc_task_lock);
266 if (rtc_callback)
267 rtc_callback->func(rtc_callback->private_data);
268 spin_unlock(&rtc_task_lock);
269 wake_up_interruptible(&rtc_wait);
270
271 kill_fasync (&rtc_async_queue, SIGIO, POLL_IN);
272
273 return IRQ_HANDLED;
274}
275#endif
276
277/*
278 * sysctl-tuning infrastructure.
279 */
280static ctl_table rtc_table[] = {
281 {
Eric W. Biederman77353622007-02-14 00:33:52 -0800282 .ctl_name = CTL_UNNUMBERED,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 .procname = "max-user-freq",
284 .data = &rtc_max_user_freq,
285 .maxlen = sizeof(int),
286 .mode = 0644,
287 .proc_handler = &proc_dointvec,
288 },
289 { .ctl_name = 0 }
290};
291
292static ctl_table rtc_root[] = {
293 {
Eric W. Biederman77353622007-02-14 00:33:52 -0800294 .ctl_name = CTL_UNNUMBERED,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 .procname = "rtc",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 .mode = 0555,
297 .child = rtc_table,
298 },
299 { .ctl_name = 0 }
300};
301
302static ctl_table dev_root[] = {
303 {
304 .ctl_name = CTL_DEV,
305 .procname = "dev",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 .mode = 0555,
307 .child = rtc_root,
308 },
309 { .ctl_name = 0 }
310};
311
312static struct ctl_table_header *sysctl_header;
313
314static int __init init_sysctl(void)
315{
Eric W. Biederman0b4d4142007-02-14 00:34:09 -0800316 sysctl_header = register_sysctl_table(dev_root);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 return 0;
318}
319
320static void __exit cleanup_sysctl(void)
321{
322 unregister_sysctl_table(sysctl_header);
323}
324
325/*
326 * Now all the various file operations that we export.
327 */
328
329static ssize_t rtc_read(struct file *file, char __user *buf,
330 size_t count, loff_t *ppos)
331{
332#ifndef RTC_IRQ
333 return -EIO;
334#else
335 DECLARE_WAITQUEUE(wait, current);
336 unsigned long data;
337 ssize_t retval;
338
339 if (rtc_has_irq == 0)
340 return -EIO;
341
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700342 /*
343 * Historically this function used to assume that sizeof(unsigned long)
344 * is the same in userspace and kernelspace. This lead to problems
345 * for configurations with multiple ABIs such a the MIPS o32 and 64
346 * ABIs supported on the same kernel. So now we support read of both
347 * 4 and 8 bytes and assume that's the sizeof(unsigned long) in the
348 * userspace ABI.
349 */
350 if (count != sizeof(unsigned int) && count != sizeof(unsigned long))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 return -EINVAL;
352
353 add_wait_queue(&rtc_wait, &wait);
354
355 do {
356 /* First make it right. Then make it fast. Putting this whole
357 * block within the parentheses of a while would be too
358 * confusing. And no, xchg() is not the answer. */
359
360 __set_current_state(TASK_INTERRUPTIBLE);
361
362 spin_lock_irq (&rtc_lock);
363 data = rtc_irq_data;
364 rtc_irq_data = 0;
365 spin_unlock_irq (&rtc_lock);
366
367 if (data != 0)
368 break;
369
370 if (file->f_flags & O_NONBLOCK) {
371 retval = -EAGAIN;
372 goto out;
373 }
374 if (signal_pending(current)) {
375 retval = -ERESTARTSYS;
376 goto out;
377 }
378 schedule();
379 } while (1);
380
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700381 if (count == sizeof(unsigned int))
382 retval = put_user(data, (unsigned int __user *)buf) ?: sizeof(int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 else
384 retval = put_user(data, (unsigned long __user *)buf) ?: sizeof(long);
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700385 if (!retval)
386 retval = count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 out:
Milind Arun Choudharycc0a8fb2007-05-08 00:30:52 -0700388 __set_current_state(TASK_RUNNING);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 remove_wait_queue(&rtc_wait, &wait);
390
391 return retval;
392#endif
393}
394
395static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
396{
397 struct rtc_time wtime;
398
399#ifdef RTC_IRQ
400 if (rtc_has_irq == 0) {
401 switch (cmd) {
402 case RTC_AIE_OFF:
403 case RTC_AIE_ON:
404 case RTC_PIE_OFF:
405 case RTC_PIE_ON:
406 case RTC_UIE_OFF:
407 case RTC_UIE_ON:
408 case RTC_IRQP_READ:
409 case RTC_IRQP_SET:
410 return -EINVAL;
411 };
412 }
413#endif
414
415 switch (cmd) {
416#ifdef RTC_IRQ
417 case RTC_AIE_OFF: /* Mask alarm int. enab. bit */
418 {
419 mask_rtc_irq_bit(RTC_AIE);
420 return 0;
421 }
422 case RTC_AIE_ON: /* Allow alarm interrupts. */
423 {
424 set_rtc_irq_bit(RTC_AIE);
425 return 0;
426 }
427 case RTC_PIE_OFF: /* Mask periodic int. enab. bit */
428 {
Takashi Iwaic3348762005-11-07 11:14:57 +0100429 unsigned long flags; /* can be called from isr via rtc_control() */
430 spin_lock_irqsave (&rtc_lock, flags);
431 mask_rtc_irq_bit_locked(RTC_PIE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 if (rtc_status & RTC_TIMER_ON) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 rtc_status &= ~RTC_TIMER_ON;
434 del_timer(&rtc_irq_timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 }
Takashi Iwaic3348762005-11-07 11:14:57 +0100436 spin_unlock_irqrestore (&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 return 0;
438 }
439 case RTC_PIE_ON: /* Allow periodic ints */
440 {
Takashi Iwaic3348762005-11-07 11:14:57 +0100441 unsigned long flags; /* can be called from isr via rtc_control() */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 /*
443 * We don't really want Joe User enabling more
444 * than 64Hz of interrupts on a multi-user machine.
445 */
446 if (!kernel && (rtc_freq > rtc_max_user_freq) &&
447 (!capable(CAP_SYS_RESOURCE)))
448 return -EACCES;
449
Takashi Iwaic3348762005-11-07 11:14:57 +0100450 spin_lock_irqsave (&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 if (!(rtc_status & RTC_TIMER_ON)) {
Jiri Slaby40565f12007-02-12 00:52:31 -0800452 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq +
453 2*HZ/100);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 rtc_status |= RTC_TIMER_ON;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 }
Takashi Iwaic3348762005-11-07 11:14:57 +0100456 set_rtc_irq_bit_locked(RTC_PIE);
457 spin_unlock_irqrestore (&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 return 0;
459 }
460 case RTC_UIE_OFF: /* Mask ints from RTC updates. */
461 {
462 mask_rtc_irq_bit(RTC_UIE);
463 return 0;
464 }
465 case RTC_UIE_ON: /* Allow ints for RTC updates. */
466 {
467 set_rtc_irq_bit(RTC_UIE);
468 return 0;
469 }
470#endif
471 case RTC_ALM_READ: /* Read the present alarm time */
472 {
473 /*
474 * This returns a struct rtc_time. Reading >= 0xc0
475 * means "don't care" or "match all". Only the tm_hour,
476 * tm_min, and tm_sec values are filled in.
477 */
478 memset(&wtime, 0, sizeof(struct rtc_time));
479 get_rtc_alm_time(&wtime);
480 break;
481 }
482 case RTC_ALM_SET: /* Store a time into the alarm */
483 {
484 /*
485 * This expects a struct rtc_time. Writing 0xff means
486 * "don't care" or "match all". Only the tm_hour,
487 * tm_min and tm_sec are used.
488 */
489 unsigned char hrs, min, sec;
490 struct rtc_time alm_tm;
491
492 if (copy_from_user(&alm_tm, (struct rtc_time __user *)arg,
493 sizeof(struct rtc_time)))
494 return -EFAULT;
495
496 hrs = alm_tm.tm_hour;
497 min = alm_tm.tm_min;
498 sec = alm_tm.tm_sec;
499
500 spin_lock_irq(&rtc_lock);
501 if (hpet_set_alarm_time(hrs, min, sec)) {
502 /*
503 * Fallthru and set alarm time in CMOS too,
504 * so that we will get proper value in RTC_ALM_READ
505 */
506 }
507 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) ||
508 RTC_ALWAYS_BCD)
509 {
510 if (sec < 60) BIN_TO_BCD(sec);
511 else sec = 0xff;
512
513 if (min < 60) BIN_TO_BCD(min);
514 else min = 0xff;
515
516 if (hrs < 24) BIN_TO_BCD(hrs);
517 else hrs = 0xff;
518 }
519 CMOS_WRITE(hrs, RTC_HOURS_ALARM);
520 CMOS_WRITE(min, RTC_MINUTES_ALARM);
521 CMOS_WRITE(sec, RTC_SECONDS_ALARM);
522 spin_unlock_irq(&rtc_lock);
523
524 return 0;
525 }
526 case RTC_RD_TIME: /* Read the time/date from RTC */
527 {
528 memset(&wtime, 0, sizeof(struct rtc_time));
529 rtc_get_rtc_time(&wtime);
530 break;
531 }
532 case RTC_SET_TIME: /* Set the RTC */
533 {
534 struct rtc_time rtc_tm;
535 unsigned char mon, day, hrs, min, sec, leap_yr;
536 unsigned char save_control, save_freq_select;
537 unsigned int yrs;
538#ifdef CONFIG_MACH_DECSTATION
539 unsigned int real_yrs;
540#endif
541
542 if (!capable(CAP_SYS_TIME))
543 return -EACCES;
544
545 if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg,
546 sizeof(struct rtc_time)))
547 return -EFAULT;
548
549 yrs = rtc_tm.tm_year + 1900;
550 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
551 day = rtc_tm.tm_mday;
552 hrs = rtc_tm.tm_hour;
553 min = rtc_tm.tm_min;
554 sec = rtc_tm.tm_sec;
555
556 if (yrs < 1970)
557 return -EINVAL;
558
559 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
560
561 if ((mon > 12) || (day == 0))
562 return -EINVAL;
563
564 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
565 return -EINVAL;
566
567 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
568 return -EINVAL;
569
570 if ((yrs -= epoch) > 255) /* They are unsigned */
571 return -EINVAL;
572
573 spin_lock_irq(&rtc_lock);
574#ifdef CONFIG_MACH_DECSTATION
575 real_yrs = yrs;
576 yrs = 72;
577
578 /*
579 * We want to keep the year set to 73 until March
580 * for non-leap years, so that Feb, 29th is handled
581 * correctly.
582 */
583 if (!leap_yr && mon < 3) {
584 real_yrs--;
585 yrs = 73;
586 }
587#endif
588 /* These limits and adjustments are independent of
589 * whether the chip is in binary mode or not.
590 */
591 if (yrs > 169) {
592 spin_unlock_irq(&rtc_lock);
593 return -EINVAL;
594 }
595 if (yrs >= 100)
596 yrs -= 100;
597
598 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
599 || RTC_ALWAYS_BCD) {
600 BIN_TO_BCD(sec);
601 BIN_TO_BCD(min);
602 BIN_TO_BCD(hrs);
603 BIN_TO_BCD(day);
604 BIN_TO_BCD(mon);
605 BIN_TO_BCD(yrs);
606 }
607
608 save_control = CMOS_READ(RTC_CONTROL);
609 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
610 save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
611 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
612
613#ifdef CONFIG_MACH_DECSTATION
614 CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
615#endif
616 CMOS_WRITE(yrs, RTC_YEAR);
617 CMOS_WRITE(mon, RTC_MONTH);
618 CMOS_WRITE(day, RTC_DAY_OF_MONTH);
619 CMOS_WRITE(hrs, RTC_HOURS);
620 CMOS_WRITE(min, RTC_MINUTES);
621 CMOS_WRITE(sec, RTC_SECONDS);
622
623 CMOS_WRITE(save_control, RTC_CONTROL);
624 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
625
626 spin_unlock_irq(&rtc_lock);
627 return 0;
628 }
629#ifdef RTC_IRQ
630 case RTC_IRQP_READ: /* Read the periodic IRQ rate. */
631 {
632 return put_user(rtc_freq, (unsigned long __user *)arg);
633 }
634 case RTC_IRQP_SET: /* Set periodic IRQ rate. */
635 {
636 int tmp = 0;
637 unsigned char val;
Takashi Iwaic3348762005-11-07 11:14:57 +0100638 unsigned long flags; /* can be called from isr via rtc_control() */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639
640 /*
641 * The max we can do is 8192Hz.
642 */
643 if ((arg < 2) || (arg > 8192))
644 return -EINVAL;
645 /*
646 * We don't really want Joe User generating more
647 * than 64Hz of interrupts on a multi-user machine.
648 */
649 if (!kernel && (arg > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE)))
650 return -EACCES;
651
652 while (arg > (1<<tmp))
653 tmp++;
654
655 /*
656 * Check that the input was really a power of 2.
657 */
658 if (arg != (1<<tmp))
659 return -EINVAL;
660
Takashi Iwaic3348762005-11-07 11:14:57 +0100661 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 if (hpet_set_periodic_freq(arg)) {
Takashi Iwaic3348762005-11-07 11:14:57 +0100663 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 return 0;
665 }
666 rtc_freq = arg;
667
668 val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
669 val |= (16 - tmp);
670 CMOS_WRITE(val, RTC_FREQ_SELECT);
Takashi Iwaic3348762005-11-07 11:14:57 +0100671 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 return 0;
673 }
674#endif
675 case RTC_EPOCH_READ: /* Read the epoch. */
676 {
677 return put_user (epoch, (unsigned long __user *)arg);
678 }
679 case RTC_EPOCH_SET: /* Set the epoch. */
680 {
681 /*
682 * There were no RTC clocks before 1900.
683 */
684 if (arg < 1900)
685 return -EINVAL;
686
687 if (!capable(CAP_SYS_TIME))
688 return -EACCES;
689
690 epoch = arg;
691 return 0;
692 }
693 default:
694 return -ENOTTY;
695 }
696 return copy_to_user((void __user *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
697}
698
699static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
700 unsigned long arg)
701{
702 return rtc_do_ioctl(cmd, arg, 0);
703}
704
705/*
706 * We enforce only one user at a time here with the open/close.
707 * Also clear the previous interrupt data on an open, and clean
708 * up things on a close.
709 */
710
711/* We use rtc_lock to protect against concurrent opens. So the BKL is not
712 * needed here. Or anywhere else in this driver. */
713static int rtc_open(struct inode *inode, struct file *file)
714{
715 spin_lock_irq (&rtc_lock);
716
717 if(rtc_status & RTC_IS_OPEN)
718 goto out_busy;
719
720 rtc_status |= RTC_IS_OPEN;
721
722 rtc_irq_data = 0;
723 spin_unlock_irq (&rtc_lock);
724 return 0;
725
726out_busy:
727 spin_unlock_irq (&rtc_lock);
728 return -EBUSY;
729}
730
731static int rtc_fasync (int fd, struct file *filp, int on)
732
733{
734 return fasync_helper (fd, filp, on, &rtc_async_queue);
735}
736
737static int rtc_release(struct inode *inode, struct file *file)
738{
739#ifdef RTC_IRQ
740 unsigned char tmp;
741
742 if (rtc_has_irq == 0)
743 goto no_irq;
744
745 /*
746 * Turn off all interrupts once the device is no longer
747 * in use, and clear the data.
748 */
749
750 spin_lock_irq(&rtc_lock);
751 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
752 tmp = CMOS_READ(RTC_CONTROL);
753 tmp &= ~RTC_PIE;
754 tmp &= ~RTC_AIE;
755 tmp &= ~RTC_UIE;
756 CMOS_WRITE(tmp, RTC_CONTROL);
757 CMOS_READ(RTC_INTR_FLAGS);
758 }
759 if (rtc_status & RTC_TIMER_ON) {
760 rtc_status &= ~RTC_TIMER_ON;
761 del_timer(&rtc_irq_timer);
762 }
763 spin_unlock_irq(&rtc_lock);
764
765 if (file->f_flags & FASYNC) {
766 rtc_fasync (-1, file, 0);
767 }
768no_irq:
769#endif
770
771 spin_lock_irq (&rtc_lock);
772 rtc_irq_data = 0;
773 rtc_status &= ~RTC_IS_OPEN;
774 spin_unlock_irq (&rtc_lock);
775 return 0;
776}
777
778#ifdef RTC_IRQ
779/* Called without the kernel lock - fine */
780static unsigned int rtc_poll(struct file *file, poll_table *wait)
781{
782 unsigned long l;
783
784 if (rtc_has_irq == 0)
785 return 0;
786
787 poll_wait(file, &rtc_wait, wait);
788
789 spin_lock_irq (&rtc_lock);
790 l = rtc_irq_data;
791 spin_unlock_irq (&rtc_lock);
792
793 if (l != 0)
794 return POLLIN | POLLRDNORM;
795 return 0;
796}
797#endif
798
799/*
800 * exported stuffs
801 */
802
803EXPORT_SYMBOL(rtc_register);
804EXPORT_SYMBOL(rtc_unregister);
805EXPORT_SYMBOL(rtc_control);
806
807int rtc_register(rtc_task_t *task)
808{
809#ifndef RTC_IRQ
810 return -EIO;
811#else
812 if (task == NULL || task->func == NULL)
813 return -EINVAL;
814 spin_lock_irq(&rtc_lock);
815 if (rtc_status & RTC_IS_OPEN) {
816 spin_unlock_irq(&rtc_lock);
817 return -EBUSY;
818 }
819 spin_lock(&rtc_task_lock);
820 if (rtc_callback) {
821 spin_unlock(&rtc_task_lock);
822 spin_unlock_irq(&rtc_lock);
823 return -EBUSY;
824 }
825 rtc_status |= RTC_IS_OPEN;
826 rtc_callback = task;
827 spin_unlock(&rtc_task_lock);
828 spin_unlock_irq(&rtc_lock);
829 return 0;
830#endif
831}
832
833int rtc_unregister(rtc_task_t *task)
834{
835#ifndef RTC_IRQ
836 return -EIO;
837#else
838 unsigned char tmp;
839
840 spin_lock_irq(&rtc_lock);
841 spin_lock(&rtc_task_lock);
842 if (rtc_callback != task) {
843 spin_unlock(&rtc_task_lock);
844 spin_unlock_irq(&rtc_lock);
845 return -ENXIO;
846 }
847 rtc_callback = NULL;
848
849 /* disable controls */
850 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
851 tmp = CMOS_READ(RTC_CONTROL);
852 tmp &= ~RTC_PIE;
853 tmp &= ~RTC_AIE;
854 tmp &= ~RTC_UIE;
855 CMOS_WRITE(tmp, RTC_CONTROL);
856 CMOS_READ(RTC_INTR_FLAGS);
857 }
858 if (rtc_status & RTC_TIMER_ON) {
859 rtc_status &= ~RTC_TIMER_ON;
860 del_timer(&rtc_irq_timer);
861 }
862 rtc_status &= ~RTC_IS_OPEN;
863 spin_unlock(&rtc_task_lock);
864 spin_unlock_irq(&rtc_lock);
865 return 0;
866#endif
867}
868
869int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
870{
871#ifndef RTC_IRQ
872 return -EIO;
873#else
Takashi Iwaic3348762005-11-07 11:14:57 +0100874 unsigned long flags;
875 if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET)
876 return -EINVAL;
877 spin_lock_irqsave(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 if (rtc_callback != task) {
Takashi Iwaic3348762005-11-07 11:14:57 +0100879 spin_unlock_irqrestore(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 return -ENXIO;
881 }
Takashi Iwaic3348762005-11-07 11:14:57 +0100882 spin_unlock_irqrestore(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 return rtc_do_ioctl(cmd, arg, 1);
884#endif
885}
886
887
888/*
889 * The various file operations we support.
890 */
891
Arjan van de Ven62322d22006-07-03 00:24:21 -0700892static const struct file_operations rtc_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 .owner = THIS_MODULE,
894 .llseek = no_llseek,
895 .read = rtc_read,
896#ifdef RTC_IRQ
897 .poll = rtc_poll,
898#endif
899 .ioctl = rtc_ioctl,
900 .open = rtc_open,
901 .release = rtc_release,
902 .fasync = rtc_fasync,
903};
904
905static struct miscdevice rtc_dev = {
906 .minor = RTC_MINOR,
907 .name = "rtc",
908 .fops = &rtc_fops,
909};
910
Jan Beulich9cef7792006-12-13 00:35:05 -0800911#ifdef CONFIG_PROC_FS
Arjan van de Ven62322d22006-07-03 00:24:21 -0700912static const struct file_operations rtc_proc_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 .owner = THIS_MODULE,
914 .open = rtc_proc_open,
915 .read = seq_read,
916 .llseek = seq_lseek,
917 .release = single_release,
918};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919#endif
920
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -0800921static resource_size_t rtc_size;
922
923static struct resource * __init rtc_request_region(resource_size_t size)
924{
925 struct resource *r;
926
927 if (RTC_IOMAPPED)
928 r = request_region(RTC_PORT(0), size, "rtc");
929 else
930 r = request_mem_region(RTC_PORT(0), size, "rtc");
931
932 if (r)
933 rtc_size = size;
934
935 return r;
936}
937
Bjorn Helgaas4c06be12007-11-14 16:59:56 -0800938static void rtc_release_region(void)
939{
940 if (RTC_IOMAPPED)
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -0800941 release_region(RTC_PORT(0), rtc_size);
Bjorn Helgaas4c06be12007-11-14 16:59:56 -0800942 else
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -0800943 release_mem_region(RTC_PORT(0), rtc_size);
Bjorn Helgaas4c06be12007-11-14 16:59:56 -0800944}
945
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946static int __init rtc_init(void)
947{
Jan Beulich9cef7792006-12-13 00:35:05 -0800948#ifdef CONFIG_PROC_FS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 struct proc_dir_entry *ent;
Jan Beulich9cef7792006-12-13 00:35:05 -0800950#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951#if defined(__alpha__) || defined(__mips__)
952 unsigned int year, ctrl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 char *guess = NULL;
954#endif
David S. Millercdee99d2007-07-19 13:59:58 -0700955#ifdef CONFIG_SPARC32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 struct linux_ebus *ebus;
957 struct linux_ebus_device *edev;
Jan Beulich9cef7792006-12-13 00:35:05 -0800958#else
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700959 void *r;
Jan Beulich9cef7792006-12-13 00:35:05 -0800960#ifdef RTC_IRQ
961 irq_handler_t rtc_int_handler_ptr;
962#endif
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700963#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964
David S. Millercdee99d2007-07-19 13:59:58 -0700965#ifdef CONFIG_SPARC32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 for_each_ebus(ebus) {
967 for_each_ebusdev(edev, ebus) {
David S. Miller690c8fd2006-06-22 19:12:03 -0700968 if(strcmp(edev->prom_node->name, "rtc") == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 rtc_port = edev->resource[0].start;
970 rtc_irq = edev->irqs[0];
971 goto found;
972 }
973 }
974 }
Jan Beulichf3e92d32006-12-13 00:35:04 -0800975 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 printk(KERN_ERR "rtc_init: no PC rtc found\n");
977 return -EIO;
978
979found:
980 if (rtc_irq == PCI_IRQ_NONE) {
981 rtc_has_irq = 0;
982 goto no_irq;
983 }
984
985 /*
986 * XXX Interrupt pin #7 in Espresso is shared between RTC and
David S. Miller53d0fc22005-09-05 23:33:05 -0700987 * PCI Slot 2 INTA# (and some INTx# in Slot 1).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 */
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -0700989 if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc", (void *)&rtc_port)) {
Jan Beulichf3e92d32006-12-13 00:35:04 -0800990 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq);
992 return -EIO;
993 }
994no_irq:
995#else
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -0800996 r = rtc_request_region(RTC_IO_EXTENT);
997
998 /*
999 * If we've already requested a smaller range (for example, because
1000 * PNPBIOS or ACPI told us how the device is configured), the request
1001 * above might fail because it's too big.
1002 *
1003 * If so, request just the range we actually use.
1004 */
1005 if (!r)
1006 r = rtc_request_region(RTC_IO_EXTENT_USED);
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -07001007 if (!r) {
Jan Beulichf3e92d32006-12-13 00:35:04 -08001008#ifdef RTC_IRQ
1009 rtc_has_irq = 0;
1010#endif
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -07001011 printk(KERN_ERR "rtc: I/O resource %lx is not free.\n",
1012 (long)(RTC_PORT(0)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 return -EIO;
1014 }
1015
1016#ifdef RTC_IRQ
1017 if (is_hpet_enabled()) {
1018 rtc_int_handler_ptr = hpet_rtc_interrupt;
1019 } else {
1020 rtc_int_handler_ptr = rtc_interrupt;
1021 }
1022
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -07001023 if(request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED, "rtc", NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 /* Yeah right, seeing as irq 8 doesn't even hit the bus. */
Jan Beulichf3e92d32006-12-13 00:35:04 -08001025 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026 printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
Bjorn Helgaas4c06be12007-11-14 16:59:56 -08001027 rtc_release_region();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 return -EIO;
1029 }
1030 hpet_rtc_timer_init();
1031
1032#endif
1033
David S. Millercdee99d2007-07-19 13:59:58 -07001034#endif /* CONFIG_SPARC32 vs. others */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035
1036 if (misc_register(&rtc_dev)) {
1037#ifdef RTC_IRQ
1038 free_irq(RTC_IRQ, NULL);
Jan Beulichf3e92d32006-12-13 00:35:04 -08001039 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040#endif
Bjorn Helgaas4c06be12007-11-14 16:59:56 -08001041 rtc_release_region();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 return -ENODEV;
1043 }
1044
Jan Beulich9cef7792006-12-13 00:35:05 -08001045#ifdef CONFIG_PROC_FS
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 ent = create_proc_entry("driver/rtc", 0, NULL);
Jan Beulich9cef7792006-12-13 00:35:05 -08001047 if (ent)
1048 ent->proc_fops = &rtc_proc_fops;
1049 else
1050 printk(KERN_WARNING "rtc: Failed to register with procfs.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052
1053#if defined(__alpha__) || defined(__mips__)
1054 rtc_freq = HZ;
1055
1056 /* Each operating system on an Alpha uses its own epoch.
1057 Let's try to guess which one we are using now. */
1058
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 if (rtc_is_updating() != 0)
Luca Falavigna47f176f2005-06-28 20:44:42 -07001060 msleep(20);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061
1062 spin_lock_irq(&rtc_lock);
1063 year = CMOS_READ(RTC_YEAR);
1064 ctrl = CMOS_READ(RTC_CONTROL);
1065 spin_unlock_irq(&rtc_lock);
1066
1067 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1068 BCD_TO_BIN(year); /* This should never happen... */
1069
1070 if (year < 20) {
1071 epoch = 2000;
1072 guess = "SRM (post-2000)";
1073 } else if (year >= 20 && year < 48) {
1074 epoch = 1980;
1075 guess = "ARC console";
1076 } else if (year >= 48 && year < 72) {
1077 epoch = 1952;
1078 guess = "Digital UNIX";
1079#if defined(__mips__)
1080 } else if (year >= 72 && year < 74) {
1081 epoch = 2000;
1082 guess = "Digital DECstation";
1083#else
1084 } else if (year >= 70) {
1085 epoch = 1900;
1086 guess = "Standard PC (1900)";
1087#endif
1088 }
1089 if (guess)
1090 printk(KERN_INFO "rtc: %s epoch (%lu) detected\n", guess, epoch);
1091#endif
1092#ifdef RTC_IRQ
1093 if (rtc_has_irq == 0)
1094 goto no_irq2;
1095
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096 spin_lock_irq(&rtc_lock);
1097 rtc_freq = 1024;
1098 if (!hpet_set_periodic_freq(rtc_freq)) {
1099 /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */
1100 CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT);
1101 }
1102 spin_unlock_irq(&rtc_lock);
1103no_irq2:
1104#endif
1105
1106 (void) init_sysctl();
1107
1108 printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
1109
1110 return 0;
1111}
1112
1113static void __exit rtc_exit (void)
1114{
1115 cleanup_sysctl();
1116 remove_proc_entry ("driver/rtc", NULL);
1117 misc_deregister(&rtc_dev);
1118
David S. Millercdee99d2007-07-19 13:59:58 -07001119#ifdef CONFIG_SPARC32
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120 if (rtc_has_irq)
1121 free_irq (rtc_irq, &rtc_port);
1122#else
Bjorn Helgaas4c06be12007-11-14 16:59:56 -08001123 rtc_release_region();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001124#ifdef RTC_IRQ
1125 if (rtc_has_irq)
1126 free_irq (RTC_IRQ, NULL);
1127#endif
David S. Millercdee99d2007-07-19 13:59:58 -07001128#endif /* CONFIG_SPARC32 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001129}
1130
1131module_init(rtc_init);
1132module_exit(rtc_exit);
1133
1134#ifdef RTC_IRQ
1135/*
1136 * At IRQ rates >= 4096Hz, an interrupt may get lost altogether.
1137 * (usually during an IDE disk interrupt, with IRQ unmasking off)
1138 * Since the interrupt handler doesn't get called, the IRQ status
1139 * byte doesn't get read, and the RTC stops generating interrupts.
1140 * A timer is set, and will call this function if/when that happens.
1141 * To get it out of this stalled state, we just read the status.
1142 * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost.
1143 * (You *really* shouldn't be trying to use a non-realtime system
1144 * for something that requires a steady > 1KHz signal anyways.)
1145 */
1146
1147static void rtc_dropped_irq(unsigned long data)
1148{
1149 unsigned long freq;
1150
1151 spin_lock_irq (&rtc_lock);
1152
1153 if (hpet_rtc_dropped_irq()) {
1154 spin_unlock_irq(&rtc_lock);
1155 return;
1156 }
1157
1158 /* Just in case someone disabled the timer from behind our back... */
1159 if (rtc_status & RTC_TIMER_ON)
1160 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
1161
1162 rtc_irq_data += ((rtc_freq/HZ)<<8);
1163 rtc_irq_data &= ~0xff;
1164 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */
1165
1166 freq = rtc_freq;
1167
1168 spin_unlock_irq(&rtc_lock);
1169
Ben Collinsb2ff4572007-07-15 23:40:11 -07001170 if (printk_ratelimit())
1171 printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", freq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172
1173 /* Now we have new data */
1174 wake_up_interruptible(&rtc_wait);
1175
1176 kill_fasync (&rtc_async_queue, SIGIO, POLL_IN);
1177}
1178#endif
1179
Jan Beulich9cef7792006-12-13 00:35:05 -08001180#ifdef CONFIG_PROC_FS
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181/*
1182 * Info exported via "/proc/driver/rtc".
1183 */
1184
1185static int rtc_proc_show(struct seq_file *seq, void *v)
1186{
1187#define YN(bit) ((ctrl & bit) ? "yes" : "no")
1188#define NY(bit) ((ctrl & bit) ? "no" : "yes")
1189 struct rtc_time tm;
1190 unsigned char batt, ctrl;
1191 unsigned long freq;
1192
1193 spin_lock_irq(&rtc_lock);
1194 batt = CMOS_READ(RTC_VALID) & RTC_VRT;
1195 ctrl = CMOS_READ(RTC_CONTROL);
1196 freq = rtc_freq;
1197 spin_unlock_irq(&rtc_lock);
1198
1199
1200 rtc_get_rtc_time(&tm);
1201
1202 /*
1203 * There is no way to tell if the luser has the RTC set for local
1204 * time or for Universal Standard Time (GMT). Probably local though.
1205 */
1206 seq_printf(seq,
1207 "rtc_time\t: %02d:%02d:%02d\n"
1208 "rtc_date\t: %04d-%02d-%02d\n"
1209 "rtc_epoch\t: %04lu\n",
1210 tm.tm_hour, tm.tm_min, tm.tm_sec,
1211 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
1212
1213 get_rtc_alm_time(&tm);
1214
1215 /*
1216 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
1217 * match any value for that particular field. Values that are
1218 * greater than a valid time, but less than 0xc0 shouldn't appear.
1219 */
1220 seq_puts(seq, "alarm\t\t: ");
1221 if (tm.tm_hour <= 24)
1222 seq_printf(seq, "%02d:", tm.tm_hour);
1223 else
1224 seq_puts(seq, "**:");
1225
1226 if (tm.tm_min <= 59)
1227 seq_printf(seq, "%02d:", tm.tm_min);
1228 else
1229 seq_puts(seq, "**:");
1230
1231 if (tm.tm_sec <= 59)
1232 seq_printf(seq, "%02d\n", tm.tm_sec);
1233 else
1234 seq_puts(seq, "**\n");
1235
1236 seq_printf(seq,
1237 "DST_enable\t: %s\n"
1238 "BCD\t\t: %s\n"
1239 "24hr\t\t: %s\n"
1240 "square_wave\t: %s\n"
1241 "alarm_IRQ\t: %s\n"
1242 "update_IRQ\t: %s\n"
1243 "periodic_IRQ\t: %s\n"
1244 "periodic_freq\t: %ld\n"
1245 "batt_status\t: %s\n",
1246 YN(RTC_DST_EN),
1247 NY(RTC_DM_BINARY),
1248 YN(RTC_24H),
1249 YN(RTC_SQWE),
1250 YN(RTC_AIE),
1251 YN(RTC_UIE),
1252 YN(RTC_PIE),
1253 freq,
1254 batt ? "okay" : "dead");
1255
1256 return 0;
1257#undef YN
1258#undef NY
1259}
1260
1261static int rtc_proc_open(struct inode *inode, struct file *file)
1262{
1263 return single_open(file, rtc_proc_show, NULL);
1264}
Jan Beulich9cef7792006-12-13 00:35:05 -08001265#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266
1267void rtc_get_rtc_time(struct rtc_time *rtc_tm)
1268{
Ingo Molnar0f749642006-07-12 09:03:10 -07001269 unsigned long uip_watchdog = jiffies, flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270 unsigned char ctrl;
1271#ifdef CONFIG_MACH_DECSTATION
1272 unsigned int real_year;
1273#endif
1274
1275 /*
1276 * read RTC once any update in progress is done. The update
Luca Falavigna47f176f2005-06-28 20:44:42 -07001277 * can take just over 2ms. We wait 20ms. There is no need to
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
1279 * If you need to know *exactly* when a second has started, enable
1280 * periodic update complete interrupts, (via ioctl) and then
1281 * immediately read /dev/rtc which will block until you get the IRQ.
1282 * Once the read clears, read the RTC time (again via ioctl). Easy.
1283 */
1284
Steven Rostedt358333a2006-09-29 01:59:04 -07001285 while (rtc_is_updating() != 0 && jiffies - uip_watchdog < 2*HZ/100)
Petr Vandrovec403fe5a2005-08-05 15:50:07 +02001286 cpu_relax();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287
1288 /*
1289 * Only the values that we read from the RTC are set. We leave
Alan Coxb7599582006-01-11 12:17:32 -08001290 * tm_wday, tm_yday and tm_isdst untouched. Note that while the
1291 * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is
1292 * only updated by the RTC when initially set to a non-zero value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001293 */
Ingo Molnar0f749642006-07-12 09:03:10 -07001294 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
1296 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
1297 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
1298 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
1299 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
1300 rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
Alan Coxb7599582006-01-11 12:17:32 -08001301 /* Only set from 2.6.16 onwards */
1302 rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK);
1303
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304#ifdef CONFIG_MACH_DECSTATION
1305 real_year = CMOS_READ(RTC_DEC_YEAR);
1306#endif
1307 ctrl = CMOS_READ(RTC_CONTROL);
Ingo Molnar0f749642006-07-12 09:03:10 -07001308 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309
1310 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1311 {
1312 BCD_TO_BIN(rtc_tm->tm_sec);
1313 BCD_TO_BIN(rtc_tm->tm_min);
1314 BCD_TO_BIN(rtc_tm->tm_hour);
1315 BCD_TO_BIN(rtc_tm->tm_mday);
1316 BCD_TO_BIN(rtc_tm->tm_mon);
1317 BCD_TO_BIN(rtc_tm->tm_year);
Alan Coxb7599582006-01-11 12:17:32 -08001318 BCD_TO_BIN(rtc_tm->tm_wday);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319 }
1320
1321#ifdef CONFIG_MACH_DECSTATION
1322 rtc_tm->tm_year += real_year - 72;
1323#endif
1324
1325 /*
1326 * Account for differences between how the RTC uses the values
1327 * and how they are defined in a struct rtc_time;
1328 */
1329 if ((rtc_tm->tm_year += (epoch - 1900)) <= 69)
1330 rtc_tm->tm_year += 100;
1331
1332 rtc_tm->tm_mon--;
1333}
1334
1335static void get_rtc_alm_time(struct rtc_time *alm_tm)
1336{
1337 unsigned char ctrl;
1338
1339 /*
1340 * Only the values that we read from the RTC are set. That
1341 * means only tm_hour, tm_min, and tm_sec.
1342 */
1343 spin_lock_irq(&rtc_lock);
1344 alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
1345 alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM);
1346 alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM);
1347 ctrl = CMOS_READ(RTC_CONTROL);
1348 spin_unlock_irq(&rtc_lock);
1349
1350 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1351 {
1352 BCD_TO_BIN(alm_tm->tm_sec);
1353 BCD_TO_BIN(alm_tm->tm_min);
1354 BCD_TO_BIN(alm_tm->tm_hour);
1355 }
1356}
1357
1358#ifdef RTC_IRQ
1359/*
1360 * Used to disable/enable interrupts for any one of UIE, AIE, PIE.
1361 * Rumour has it that if you frob the interrupt enable/disable
1362 * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to
1363 * ensure you actually start getting interrupts. Probably for
1364 * compatibility with older/broken chipset RTC implementations.
1365 * We also clear out any old irq data after an ioctl() that
1366 * meddles with the interrupt enable/disable bits.
1367 */
1368
Takashi Iwaic3348762005-11-07 11:14:57 +01001369static void mask_rtc_irq_bit_locked(unsigned char bit)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370{
1371 unsigned char val;
1372
Takashi Iwaic3348762005-11-07 11:14:57 +01001373 if (hpet_mask_rtc_irq_bit(bit))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001375 val = CMOS_READ(RTC_CONTROL);
1376 val &= ~bit;
1377 CMOS_WRITE(val, RTC_CONTROL);
1378 CMOS_READ(RTC_INTR_FLAGS);
1379
1380 rtc_irq_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001381}
1382
Takashi Iwaic3348762005-11-07 11:14:57 +01001383static void set_rtc_irq_bit_locked(unsigned char bit)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384{
1385 unsigned char val;
1386
Takashi Iwaic3348762005-11-07 11:14:57 +01001387 if (hpet_set_rtc_irq_bit(bit))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 val = CMOS_READ(RTC_CONTROL);
1390 val |= bit;
1391 CMOS_WRITE(val, RTC_CONTROL);
1392 CMOS_READ(RTC_INTR_FLAGS);
1393
1394 rtc_irq_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395}
1396#endif
1397
1398MODULE_AUTHOR("Paul Gortmaker");
1399MODULE_LICENSE("GPL");
1400MODULE_ALIAS_MISCDEV(RTC_MINOR);