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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
38 * 1.10 Paul Barton-Davis: add support for async I/O
39 * 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.
44 * 1.11 Takashi Iwai: Kernel access functions
45 * 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
Alan Coxb7599582006-01-11 12:17:32 -080049 * 1.12ac Alan Cox: Allow read access to the day of week register
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 */
51
Alan Coxb7599582006-01-11 12:17:32 -080052#define RTC_VERSION "1.12ac"
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54#define RTC_IO_EXTENT 0x8
55
56/*
57 * Note that *all* calls to CMOS_READ and CMOS_WRITE are done with
58 * interrupts disabled. Due to the index-port/data-port (0x70/0x71)
59 * design of the RTC, we don't want two different things trying to
60 * get to it at once. (e.g. the periodic 11 min sync from time.c vs.
61 * this driver.)
62 */
63
Linus Torvalds1da177e2005-04-16 15:20:36 -070064#include <linux/interrupt.h>
65#include <linux/module.h>
66#include <linux/kernel.h>
67#include <linux/types.h>
68#include <linux/miscdevice.h>
69#include <linux/ioport.h>
70#include <linux/fcntl.h>
71#include <linux/mc146818rtc.h>
72#include <linux/init.h>
73#include <linux/poll.h>
74#include <linux/proc_fs.h>
75#include <linux/seq_file.h>
76#include <linux/spinlock.h>
77#include <linux/sysctl.h>
78#include <linux/wait.h>
79#include <linux/bcd.h>
Luca Falavigna47f176f2005-06-28 20:44:42 -070080#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82#include <asm/current.h>
83#include <asm/uaccess.h>
84#include <asm/system.h>
85
86#if defined(__i386__)
87#include <asm/hpet.h>
88#endif
89
90#ifdef __sparc__
91#include <linux/pci.h>
92#include <asm/ebus.h>
93#ifdef __sparc_v9__
94#include <asm/isa.h>
95#endif
96
97static unsigned long rtc_port;
98static int rtc_irq = PCI_IRQ_NONE;
99#endif
100
101#ifdef CONFIG_HPET_RTC_IRQ
102#undef RTC_IRQ
103#endif
104
105#ifdef RTC_IRQ
106static int rtc_has_irq = 1;
107#endif
108
109#ifndef CONFIG_HPET_EMULATE_RTC
110#define is_hpet_enabled() 0
111#define hpet_set_alarm_time(hrs, min, sec) 0
112#define hpet_set_periodic_freq(arg) 0
113#define hpet_mask_rtc_irq_bit(arg) 0
114#define hpet_set_rtc_irq_bit(arg) 0
115#define hpet_rtc_timer_init() do { } while (0)
116#define hpet_rtc_dropped_irq() 0
117static inline irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs) {return 0;}
118#else
119extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs);
120#endif
121
122/*
123 * We sponge a minor off of the misc major. No need slurping
124 * up another valuable major dev number for this. If you add
125 * an ioctl, make sure you don't conflict with SPARC's RTC
126 * ioctls.
127 */
128
129static struct fasync_struct *rtc_async_queue;
130
131static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
132
133#ifdef RTC_IRQ
134static struct timer_list rtc_irq_timer;
135#endif
136
137static ssize_t rtc_read(struct file *file, char __user *buf,
138 size_t count, loff_t *ppos);
139
140static int rtc_ioctl(struct inode *inode, struct file *file,
141 unsigned int cmd, unsigned long arg);
142
143#ifdef RTC_IRQ
144static unsigned int rtc_poll(struct file *file, poll_table *wait);
145#endif
146
147static void get_rtc_alm_time (struct rtc_time *alm_tm);
148#ifdef RTC_IRQ
149static void rtc_dropped_irq(unsigned long data);
150
Takashi Iwaic3348762005-11-07 11:14:57 +0100151static void set_rtc_irq_bit_locked(unsigned char bit);
152static void mask_rtc_irq_bit_locked(unsigned char bit);
153
154static inline void set_rtc_irq_bit(unsigned char bit)
155{
156 spin_lock_irq(&rtc_lock);
157 set_rtc_irq_bit_locked(bit);
158 spin_unlock_irq(&rtc_lock);
159}
160
161static void mask_rtc_irq_bit(unsigned char bit)
162{
163 spin_lock_irq(&rtc_lock);
164 mask_rtc_irq_bit_locked(bit);
165 spin_unlock_irq(&rtc_lock);
166}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167#endif
168
169static int rtc_proc_open(struct inode *inode, struct file *file);
170
171/*
172 * Bits in rtc_status. (6 bits of room for future expansion)
173 */
174
175#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
176#define RTC_TIMER_ON 0x02 /* missed irq timer active */
177
178/*
179 * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is
180 * protected by the big kernel lock. However, ioctl can still disable the timer
181 * in rtc_status and then with del_timer after the interrupt has read
182 * rtc_status but before mod_timer is called, which would then reenable the
183 * timer (but you would need to have an awful timing before you'd trip on it)
184 */
185static unsigned long rtc_status = 0; /* bitmapped status byte. */
186static unsigned long rtc_freq = 0; /* Current periodic IRQ rate */
187static unsigned long rtc_irq_data = 0; /* our output to the world */
188static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */
189
190#ifdef RTC_IRQ
191/*
192 * rtc_task_lock nests inside rtc_lock.
193 */
194static DEFINE_SPINLOCK(rtc_task_lock);
195static rtc_task_t *rtc_callback = NULL;
196#endif
197
198/*
199 * If this driver ever becomes modularised, it will be really nice
200 * to make the epoch retain its value across module reload...
201 */
202
203static unsigned long epoch = 1900; /* year corresponding to 0x00 */
204
205static const unsigned char days_in_mo[] =
206{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
207
208/*
209 * Returns true if a clock update is in progress
210 */
211static inline unsigned char rtc_is_updating(void)
212{
213 unsigned char uip;
214
215 spin_lock_irq(&rtc_lock);
216 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
217 spin_unlock_irq(&rtc_lock);
218 return uip;
219}
220
221#ifdef RTC_IRQ
222/*
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -0700223 * A very tiny interrupt handler. It runs with IRQF_DISABLED set,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 * but there is possibility of conflicting with the set_rtc_mmss()
225 * call (the rtc irq and the timer irq can easily run at the same
226 * time in two different CPUs). So we need to serialize
227 * accesses to the chip with the rtc_lock spinlock that each
228 * architecture should implement in the timer code.
229 * (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.)
230 */
231
232irqreturn_t rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
233{
234 /*
235 * Can be an alarm interrupt, update complete interrupt,
236 * or a periodic interrupt. We store the status in the
237 * low byte and the number of interrupts received since
238 * the last read in the remainder of rtc_irq_data.
239 */
240
241 spin_lock (&rtc_lock);
242 rtc_irq_data += 0x100;
243 rtc_irq_data &= ~0xff;
244 if (is_hpet_enabled()) {
245 /*
246 * In this case it is HPET RTC interrupt handler
247 * calling us, with the interrupt information
248 * passed as arg1, instead of irq.
249 */
250 rtc_irq_data |= (unsigned long)irq & 0xF0;
251 } else {
252 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0);
253 }
254
255 if (rtc_status & RTC_TIMER_ON)
256 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
257
258 spin_unlock (&rtc_lock);
259
260 /* Now do the rest of the actions */
261 spin_lock(&rtc_task_lock);
262 if (rtc_callback)
263 rtc_callback->func(rtc_callback->private_data);
264 spin_unlock(&rtc_task_lock);
265 wake_up_interruptible(&rtc_wait);
266
267 kill_fasync (&rtc_async_queue, SIGIO, POLL_IN);
268
269 return IRQ_HANDLED;
270}
271#endif
272
273/*
274 * sysctl-tuning infrastructure.
275 */
276static ctl_table rtc_table[] = {
277 {
278 .ctl_name = 1,
279 .procname = "max-user-freq",
280 .data = &rtc_max_user_freq,
281 .maxlen = sizeof(int),
282 .mode = 0644,
283 .proc_handler = &proc_dointvec,
284 },
285 { .ctl_name = 0 }
286};
287
288static ctl_table rtc_root[] = {
289 {
290 .ctl_name = 1,
291 .procname = "rtc",
292 .maxlen = 0,
293 .mode = 0555,
294 .child = rtc_table,
295 },
296 { .ctl_name = 0 }
297};
298
299static ctl_table dev_root[] = {
300 {
301 .ctl_name = CTL_DEV,
302 .procname = "dev",
303 .maxlen = 0,
304 .mode = 0555,
305 .child = rtc_root,
306 },
307 { .ctl_name = 0 }
308};
309
310static struct ctl_table_header *sysctl_header;
311
312static int __init init_sysctl(void)
313{
314 sysctl_header = register_sysctl_table(dev_root, 0);
315 return 0;
316}
317
318static void __exit cleanup_sysctl(void)
319{
320 unregister_sysctl_table(sysctl_header);
321}
322
323/*
324 * Now all the various file operations that we export.
325 */
326
327static ssize_t rtc_read(struct file *file, char __user *buf,
328 size_t count, loff_t *ppos)
329{
330#ifndef RTC_IRQ
331 return -EIO;
332#else
333 DECLARE_WAITQUEUE(wait, current);
334 unsigned long data;
335 ssize_t retval;
336
337 if (rtc_has_irq == 0)
338 return -EIO;
339
340 if (count < sizeof(unsigned))
341 return -EINVAL;
342
343 add_wait_queue(&rtc_wait, &wait);
344
345 do {
346 /* First make it right. Then make it fast. Putting this whole
347 * block within the parentheses of a while would be too
348 * confusing. And no, xchg() is not the answer. */
349
350 __set_current_state(TASK_INTERRUPTIBLE);
351
352 spin_lock_irq (&rtc_lock);
353 data = rtc_irq_data;
354 rtc_irq_data = 0;
355 spin_unlock_irq (&rtc_lock);
356
357 if (data != 0)
358 break;
359
360 if (file->f_flags & O_NONBLOCK) {
361 retval = -EAGAIN;
362 goto out;
363 }
364 if (signal_pending(current)) {
365 retval = -ERESTARTSYS;
366 goto out;
367 }
368 schedule();
369 } while (1);
370
371 if (count < sizeof(unsigned long))
372 retval = put_user(data, (unsigned int __user *)buf) ?: sizeof(int);
373 else
374 retval = put_user(data, (unsigned long __user *)buf) ?: sizeof(long);
375 out:
376 current->state = TASK_RUNNING;
377 remove_wait_queue(&rtc_wait, &wait);
378
379 return retval;
380#endif
381}
382
383static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
384{
385 struct rtc_time wtime;
386
387#ifdef RTC_IRQ
388 if (rtc_has_irq == 0) {
389 switch (cmd) {
390 case RTC_AIE_OFF:
391 case RTC_AIE_ON:
392 case RTC_PIE_OFF:
393 case RTC_PIE_ON:
394 case RTC_UIE_OFF:
395 case RTC_UIE_ON:
396 case RTC_IRQP_READ:
397 case RTC_IRQP_SET:
398 return -EINVAL;
399 };
400 }
401#endif
402
403 switch (cmd) {
404#ifdef RTC_IRQ
405 case RTC_AIE_OFF: /* Mask alarm int. enab. bit */
406 {
407 mask_rtc_irq_bit(RTC_AIE);
408 return 0;
409 }
410 case RTC_AIE_ON: /* Allow alarm interrupts. */
411 {
412 set_rtc_irq_bit(RTC_AIE);
413 return 0;
414 }
415 case RTC_PIE_OFF: /* Mask periodic int. enab. bit */
416 {
Takashi Iwaic3348762005-11-07 11:14:57 +0100417 unsigned long flags; /* can be called from isr via rtc_control() */
418 spin_lock_irqsave (&rtc_lock, flags);
419 mask_rtc_irq_bit_locked(RTC_PIE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 if (rtc_status & RTC_TIMER_ON) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 rtc_status &= ~RTC_TIMER_ON;
422 del_timer(&rtc_irq_timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 }
Takashi Iwaic3348762005-11-07 11:14:57 +0100424 spin_unlock_irqrestore (&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 return 0;
426 }
427 case RTC_PIE_ON: /* Allow periodic ints */
428 {
Takashi Iwaic3348762005-11-07 11:14:57 +0100429 unsigned long flags; /* can be called from isr via rtc_control() */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 /*
431 * We don't really want Joe User enabling more
432 * than 64Hz of interrupts on a multi-user machine.
433 */
434 if (!kernel && (rtc_freq > rtc_max_user_freq) &&
435 (!capable(CAP_SYS_RESOURCE)))
436 return -EACCES;
437
Takashi Iwaic3348762005-11-07 11:14:57 +0100438 spin_lock_irqsave (&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 if (!(rtc_status & RTC_TIMER_ON)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 rtc_irq_timer.expires = jiffies + HZ/rtc_freq + 2*HZ/100;
441 add_timer(&rtc_irq_timer);
442 rtc_status |= RTC_TIMER_ON;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 }
Takashi Iwaic3348762005-11-07 11:14:57 +0100444 set_rtc_irq_bit_locked(RTC_PIE);
445 spin_unlock_irqrestore (&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 return 0;
447 }
448 case RTC_UIE_OFF: /* Mask ints from RTC updates. */
449 {
450 mask_rtc_irq_bit(RTC_UIE);
451 return 0;
452 }
453 case RTC_UIE_ON: /* Allow ints for RTC updates. */
454 {
455 set_rtc_irq_bit(RTC_UIE);
456 return 0;
457 }
458#endif
459 case RTC_ALM_READ: /* Read the present alarm time */
460 {
461 /*
462 * This returns a struct rtc_time. Reading >= 0xc0
463 * means "don't care" or "match all". Only the tm_hour,
464 * tm_min, and tm_sec values are filled in.
465 */
466 memset(&wtime, 0, sizeof(struct rtc_time));
467 get_rtc_alm_time(&wtime);
468 break;
469 }
470 case RTC_ALM_SET: /* Store a time into the alarm */
471 {
472 /*
473 * This expects a struct rtc_time. Writing 0xff means
474 * "don't care" or "match all". Only the tm_hour,
475 * tm_min and tm_sec are used.
476 */
477 unsigned char hrs, min, sec;
478 struct rtc_time alm_tm;
479
480 if (copy_from_user(&alm_tm, (struct rtc_time __user *)arg,
481 sizeof(struct rtc_time)))
482 return -EFAULT;
483
484 hrs = alm_tm.tm_hour;
485 min = alm_tm.tm_min;
486 sec = alm_tm.tm_sec;
487
488 spin_lock_irq(&rtc_lock);
489 if (hpet_set_alarm_time(hrs, min, sec)) {
490 /*
491 * Fallthru and set alarm time in CMOS too,
492 * so that we will get proper value in RTC_ALM_READ
493 */
494 }
495 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) ||
496 RTC_ALWAYS_BCD)
497 {
498 if (sec < 60) BIN_TO_BCD(sec);
499 else sec = 0xff;
500
501 if (min < 60) BIN_TO_BCD(min);
502 else min = 0xff;
503
504 if (hrs < 24) BIN_TO_BCD(hrs);
505 else hrs = 0xff;
506 }
507 CMOS_WRITE(hrs, RTC_HOURS_ALARM);
508 CMOS_WRITE(min, RTC_MINUTES_ALARM);
509 CMOS_WRITE(sec, RTC_SECONDS_ALARM);
510 spin_unlock_irq(&rtc_lock);
511
512 return 0;
513 }
514 case RTC_RD_TIME: /* Read the time/date from RTC */
515 {
516 memset(&wtime, 0, sizeof(struct rtc_time));
517 rtc_get_rtc_time(&wtime);
518 break;
519 }
520 case RTC_SET_TIME: /* Set the RTC */
521 {
522 struct rtc_time rtc_tm;
523 unsigned char mon, day, hrs, min, sec, leap_yr;
524 unsigned char save_control, save_freq_select;
525 unsigned int yrs;
526#ifdef CONFIG_MACH_DECSTATION
527 unsigned int real_yrs;
528#endif
529
530 if (!capable(CAP_SYS_TIME))
531 return -EACCES;
532
533 if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg,
534 sizeof(struct rtc_time)))
535 return -EFAULT;
536
537 yrs = rtc_tm.tm_year + 1900;
538 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
539 day = rtc_tm.tm_mday;
540 hrs = rtc_tm.tm_hour;
541 min = rtc_tm.tm_min;
542 sec = rtc_tm.tm_sec;
543
544 if (yrs < 1970)
545 return -EINVAL;
546
547 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
548
549 if ((mon > 12) || (day == 0))
550 return -EINVAL;
551
552 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
553 return -EINVAL;
554
555 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
556 return -EINVAL;
557
558 if ((yrs -= epoch) > 255) /* They are unsigned */
559 return -EINVAL;
560
561 spin_lock_irq(&rtc_lock);
562#ifdef CONFIG_MACH_DECSTATION
563 real_yrs = yrs;
564 yrs = 72;
565
566 /*
567 * We want to keep the year set to 73 until March
568 * for non-leap years, so that Feb, 29th is handled
569 * correctly.
570 */
571 if (!leap_yr && mon < 3) {
572 real_yrs--;
573 yrs = 73;
574 }
575#endif
576 /* These limits and adjustments are independent of
577 * whether the chip is in binary mode or not.
578 */
579 if (yrs > 169) {
580 spin_unlock_irq(&rtc_lock);
581 return -EINVAL;
582 }
583 if (yrs >= 100)
584 yrs -= 100;
585
586 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
587 || RTC_ALWAYS_BCD) {
588 BIN_TO_BCD(sec);
589 BIN_TO_BCD(min);
590 BIN_TO_BCD(hrs);
591 BIN_TO_BCD(day);
592 BIN_TO_BCD(mon);
593 BIN_TO_BCD(yrs);
594 }
595
596 save_control = CMOS_READ(RTC_CONTROL);
597 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
598 save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
599 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
600
601#ifdef CONFIG_MACH_DECSTATION
602 CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
603#endif
604 CMOS_WRITE(yrs, RTC_YEAR);
605 CMOS_WRITE(mon, RTC_MONTH);
606 CMOS_WRITE(day, RTC_DAY_OF_MONTH);
607 CMOS_WRITE(hrs, RTC_HOURS);
608 CMOS_WRITE(min, RTC_MINUTES);
609 CMOS_WRITE(sec, RTC_SECONDS);
610
611 CMOS_WRITE(save_control, RTC_CONTROL);
612 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
613
614 spin_unlock_irq(&rtc_lock);
615 return 0;
616 }
617#ifdef RTC_IRQ
618 case RTC_IRQP_READ: /* Read the periodic IRQ rate. */
619 {
620 return put_user(rtc_freq, (unsigned long __user *)arg);
621 }
622 case RTC_IRQP_SET: /* Set periodic IRQ rate. */
623 {
624 int tmp = 0;
625 unsigned char val;
Takashi Iwaic3348762005-11-07 11:14:57 +0100626 unsigned long flags; /* can be called from isr via rtc_control() */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627
628 /*
629 * The max we can do is 8192Hz.
630 */
631 if ((arg < 2) || (arg > 8192))
632 return -EINVAL;
633 /*
634 * We don't really want Joe User generating more
635 * than 64Hz of interrupts on a multi-user machine.
636 */
637 if (!kernel && (arg > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE)))
638 return -EACCES;
639
640 while (arg > (1<<tmp))
641 tmp++;
642
643 /*
644 * Check that the input was really a power of 2.
645 */
646 if (arg != (1<<tmp))
647 return -EINVAL;
648
Takashi Iwaic3348762005-11-07 11:14:57 +0100649 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 if (hpet_set_periodic_freq(arg)) {
Takashi Iwaic3348762005-11-07 11:14:57 +0100651 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 return 0;
653 }
654 rtc_freq = arg;
655
656 val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
657 val |= (16 - tmp);
658 CMOS_WRITE(val, RTC_FREQ_SELECT);
Takashi Iwaic3348762005-11-07 11:14:57 +0100659 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 return 0;
661 }
662#endif
663 case RTC_EPOCH_READ: /* Read the epoch. */
664 {
665 return put_user (epoch, (unsigned long __user *)arg);
666 }
667 case RTC_EPOCH_SET: /* Set the epoch. */
668 {
669 /*
670 * There were no RTC clocks before 1900.
671 */
672 if (arg < 1900)
673 return -EINVAL;
674
675 if (!capable(CAP_SYS_TIME))
676 return -EACCES;
677
678 epoch = arg;
679 return 0;
680 }
681 default:
682 return -ENOTTY;
683 }
684 return copy_to_user((void __user *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
685}
686
687static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
688 unsigned long arg)
689{
690 return rtc_do_ioctl(cmd, arg, 0);
691}
692
693/*
694 * We enforce only one user at a time here with the open/close.
695 * Also clear the previous interrupt data on an open, and clean
696 * up things on a close.
697 */
698
699/* We use rtc_lock to protect against concurrent opens. So the BKL is not
700 * needed here. Or anywhere else in this driver. */
701static int rtc_open(struct inode *inode, struct file *file)
702{
703 spin_lock_irq (&rtc_lock);
704
705 if(rtc_status & RTC_IS_OPEN)
706 goto out_busy;
707
708 rtc_status |= RTC_IS_OPEN;
709
710 rtc_irq_data = 0;
711 spin_unlock_irq (&rtc_lock);
712 return 0;
713
714out_busy:
715 spin_unlock_irq (&rtc_lock);
716 return -EBUSY;
717}
718
719static int rtc_fasync (int fd, struct file *filp, int on)
720
721{
722 return fasync_helper (fd, filp, on, &rtc_async_queue);
723}
724
725static int rtc_release(struct inode *inode, struct file *file)
726{
727#ifdef RTC_IRQ
728 unsigned char tmp;
729
730 if (rtc_has_irq == 0)
731 goto no_irq;
732
733 /*
734 * Turn off all interrupts once the device is no longer
735 * in use, and clear the data.
736 */
737
738 spin_lock_irq(&rtc_lock);
739 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
740 tmp = CMOS_READ(RTC_CONTROL);
741 tmp &= ~RTC_PIE;
742 tmp &= ~RTC_AIE;
743 tmp &= ~RTC_UIE;
744 CMOS_WRITE(tmp, RTC_CONTROL);
745 CMOS_READ(RTC_INTR_FLAGS);
746 }
747 if (rtc_status & RTC_TIMER_ON) {
748 rtc_status &= ~RTC_TIMER_ON;
749 del_timer(&rtc_irq_timer);
750 }
751 spin_unlock_irq(&rtc_lock);
752
753 if (file->f_flags & FASYNC) {
754 rtc_fasync (-1, file, 0);
755 }
756no_irq:
757#endif
758
759 spin_lock_irq (&rtc_lock);
760 rtc_irq_data = 0;
761 rtc_status &= ~RTC_IS_OPEN;
762 spin_unlock_irq (&rtc_lock);
763 return 0;
764}
765
766#ifdef RTC_IRQ
767/* Called without the kernel lock - fine */
768static unsigned int rtc_poll(struct file *file, poll_table *wait)
769{
770 unsigned long l;
771
772 if (rtc_has_irq == 0)
773 return 0;
774
775 poll_wait(file, &rtc_wait, wait);
776
777 spin_lock_irq (&rtc_lock);
778 l = rtc_irq_data;
779 spin_unlock_irq (&rtc_lock);
780
781 if (l != 0)
782 return POLLIN | POLLRDNORM;
783 return 0;
784}
785#endif
786
787/*
788 * exported stuffs
789 */
790
791EXPORT_SYMBOL(rtc_register);
792EXPORT_SYMBOL(rtc_unregister);
793EXPORT_SYMBOL(rtc_control);
794
795int rtc_register(rtc_task_t *task)
796{
797#ifndef RTC_IRQ
798 return -EIO;
799#else
800 if (task == NULL || task->func == NULL)
801 return -EINVAL;
802 spin_lock_irq(&rtc_lock);
803 if (rtc_status & RTC_IS_OPEN) {
804 spin_unlock_irq(&rtc_lock);
805 return -EBUSY;
806 }
807 spin_lock(&rtc_task_lock);
808 if (rtc_callback) {
809 spin_unlock(&rtc_task_lock);
810 spin_unlock_irq(&rtc_lock);
811 return -EBUSY;
812 }
813 rtc_status |= RTC_IS_OPEN;
814 rtc_callback = task;
815 spin_unlock(&rtc_task_lock);
816 spin_unlock_irq(&rtc_lock);
817 return 0;
818#endif
819}
820
821int rtc_unregister(rtc_task_t *task)
822{
823#ifndef RTC_IRQ
824 return -EIO;
825#else
826 unsigned char tmp;
827
828 spin_lock_irq(&rtc_lock);
829 spin_lock(&rtc_task_lock);
830 if (rtc_callback != task) {
831 spin_unlock(&rtc_task_lock);
832 spin_unlock_irq(&rtc_lock);
833 return -ENXIO;
834 }
835 rtc_callback = NULL;
836
837 /* disable controls */
838 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
839 tmp = CMOS_READ(RTC_CONTROL);
840 tmp &= ~RTC_PIE;
841 tmp &= ~RTC_AIE;
842 tmp &= ~RTC_UIE;
843 CMOS_WRITE(tmp, RTC_CONTROL);
844 CMOS_READ(RTC_INTR_FLAGS);
845 }
846 if (rtc_status & RTC_TIMER_ON) {
847 rtc_status &= ~RTC_TIMER_ON;
848 del_timer(&rtc_irq_timer);
849 }
850 rtc_status &= ~RTC_IS_OPEN;
851 spin_unlock(&rtc_task_lock);
852 spin_unlock_irq(&rtc_lock);
853 return 0;
854#endif
855}
856
857int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
858{
859#ifndef RTC_IRQ
860 return -EIO;
861#else
Takashi Iwaic3348762005-11-07 11:14:57 +0100862 unsigned long flags;
863 if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET)
864 return -EINVAL;
865 spin_lock_irqsave(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 if (rtc_callback != task) {
Takashi Iwaic3348762005-11-07 11:14:57 +0100867 spin_unlock_irqrestore(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 return -ENXIO;
869 }
Takashi Iwaic3348762005-11-07 11:14:57 +0100870 spin_unlock_irqrestore(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 return rtc_do_ioctl(cmd, arg, 1);
872#endif
873}
874
875
876/*
877 * The various file operations we support.
878 */
879
Arjan van de Ven62322d22006-07-03 00:24:21 -0700880static const struct file_operations rtc_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 .owner = THIS_MODULE,
882 .llseek = no_llseek,
883 .read = rtc_read,
884#ifdef RTC_IRQ
885 .poll = rtc_poll,
886#endif
887 .ioctl = rtc_ioctl,
888 .open = rtc_open,
889 .release = rtc_release,
890 .fasync = rtc_fasync,
891};
892
893static struct miscdevice rtc_dev = {
894 .minor = RTC_MINOR,
895 .name = "rtc",
896 .fops = &rtc_fops,
897};
898
Arjan van de Ven62322d22006-07-03 00:24:21 -0700899static const struct file_operations rtc_proc_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 .owner = THIS_MODULE,
901 .open = rtc_proc_open,
902 .read = seq_read,
903 .llseek = seq_lseek,
904 .release = single_release,
905};
906
907#if defined(RTC_IRQ) && !defined(__sparc__)
908static irqreturn_t (*rtc_int_handler_ptr)(int irq, void *dev_id, struct pt_regs *regs);
909#endif
910
911static int __init rtc_init(void)
912{
913 struct proc_dir_entry *ent;
914#if defined(__alpha__) || defined(__mips__)
915 unsigned int year, ctrl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 char *guess = NULL;
917#endif
918#ifdef __sparc__
919 struct linux_ebus *ebus;
920 struct linux_ebus_device *edev;
921#ifdef __sparc_v9__
922 struct sparc_isa_bridge *isa_br;
923 struct sparc_isa_device *isa_dev;
924#endif
925#endif
926
927#ifdef __sparc__
928 for_each_ebus(ebus) {
929 for_each_ebusdev(edev, ebus) {
David S. Miller690c8fd2006-06-22 19:12:03 -0700930 if(strcmp(edev->prom_node->name, "rtc") == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 rtc_port = edev->resource[0].start;
932 rtc_irq = edev->irqs[0];
933 goto found;
934 }
935 }
936 }
937#ifdef __sparc_v9__
938 for_each_isa(isa_br) {
939 for_each_isadev(isa_dev, isa_br) {
David S. Miller690c8fd2006-06-22 19:12:03 -0700940 if (strcmp(isa_dev->prom_node->name, "rtc") == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 rtc_port = isa_dev->resource.start;
942 rtc_irq = isa_dev->irq;
943 goto found;
944 }
945 }
946 }
947#endif
948 printk(KERN_ERR "rtc_init: no PC rtc found\n");
949 return -EIO;
950
951found:
952 if (rtc_irq == PCI_IRQ_NONE) {
953 rtc_has_irq = 0;
954 goto no_irq;
955 }
956
957 /*
958 * XXX Interrupt pin #7 in Espresso is shared between RTC and
David S. Miller53d0fc22005-09-05 23:33:05 -0700959 * PCI Slot 2 INTA# (and some INTx# in Slot 1).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 */
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -0700961 if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc", (void *)&rtc_port)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq);
963 return -EIO;
964 }
965no_irq:
966#else
967 if (!request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc")) {
968 printk(KERN_ERR "rtc: I/O port %d is not free.\n", RTC_PORT (0));
969 return -EIO;
970 }
971
972#ifdef RTC_IRQ
973 if (is_hpet_enabled()) {
974 rtc_int_handler_ptr = hpet_rtc_interrupt;
975 } else {
976 rtc_int_handler_ptr = rtc_interrupt;
977 }
978
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -0700979 if(request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED, "rtc", NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 /* Yeah right, seeing as irq 8 doesn't even hit the bus. */
981 printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
982 release_region(RTC_PORT(0), RTC_IO_EXTENT);
983 return -EIO;
984 }
985 hpet_rtc_timer_init();
986
987#endif
988
989#endif /* __sparc__ vs. others */
990
991 if (misc_register(&rtc_dev)) {
992#ifdef RTC_IRQ
993 free_irq(RTC_IRQ, NULL);
994#endif
995 release_region(RTC_PORT(0), RTC_IO_EXTENT);
996 return -ENODEV;
997 }
998
999 ent = create_proc_entry("driver/rtc", 0, NULL);
1000 if (!ent) {
1001#ifdef RTC_IRQ
1002 free_irq(RTC_IRQ, NULL);
1003#endif
1004 release_region(RTC_PORT(0), RTC_IO_EXTENT);
1005 misc_deregister(&rtc_dev);
1006 return -ENOMEM;
1007 }
1008 ent->proc_fops = &rtc_proc_fops;
1009
1010#if defined(__alpha__) || defined(__mips__)
1011 rtc_freq = HZ;
1012
1013 /* Each operating system on an Alpha uses its own epoch.
1014 Let's try to guess which one we are using now. */
1015
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 if (rtc_is_updating() != 0)
Luca Falavigna47f176f2005-06-28 20:44:42 -07001017 msleep(20);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018
1019 spin_lock_irq(&rtc_lock);
1020 year = CMOS_READ(RTC_YEAR);
1021 ctrl = CMOS_READ(RTC_CONTROL);
1022 spin_unlock_irq(&rtc_lock);
1023
1024 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1025 BCD_TO_BIN(year); /* This should never happen... */
1026
1027 if (year < 20) {
1028 epoch = 2000;
1029 guess = "SRM (post-2000)";
1030 } else if (year >= 20 && year < 48) {
1031 epoch = 1980;
1032 guess = "ARC console";
1033 } else if (year >= 48 && year < 72) {
1034 epoch = 1952;
1035 guess = "Digital UNIX";
1036#if defined(__mips__)
1037 } else if (year >= 72 && year < 74) {
1038 epoch = 2000;
1039 guess = "Digital DECstation";
1040#else
1041 } else if (year >= 70) {
1042 epoch = 1900;
1043 guess = "Standard PC (1900)";
1044#endif
1045 }
1046 if (guess)
1047 printk(KERN_INFO "rtc: %s epoch (%lu) detected\n", guess, epoch);
1048#endif
1049#ifdef RTC_IRQ
1050 if (rtc_has_irq == 0)
1051 goto no_irq2;
1052
1053 init_timer(&rtc_irq_timer);
1054 rtc_irq_timer.function = rtc_dropped_irq;
1055 spin_lock_irq(&rtc_lock);
1056 rtc_freq = 1024;
1057 if (!hpet_set_periodic_freq(rtc_freq)) {
1058 /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */
1059 CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT);
1060 }
1061 spin_unlock_irq(&rtc_lock);
1062no_irq2:
1063#endif
1064
1065 (void) init_sysctl();
1066
1067 printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
1068
1069 return 0;
1070}
1071
1072static void __exit rtc_exit (void)
1073{
1074 cleanup_sysctl();
1075 remove_proc_entry ("driver/rtc", NULL);
1076 misc_deregister(&rtc_dev);
1077
1078#ifdef __sparc__
1079 if (rtc_has_irq)
1080 free_irq (rtc_irq, &rtc_port);
1081#else
1082 release_region (RTC_PORT (0), RTC_IO_EXTENT);
1083#ifdef RTC_IRQ
1084 if (rtc_has_irq)
1085 free_irq (RTC_IRQ, NULL);
1086#endif
1087#endif /* __sparc__ */
1088}
1089
1090module_init(rtc_init);
1091module_exit(rtc_exit);
1092
1093#ifdef RTC_IRQ
1094/*
1095 * At IRQ rates >= 4096Hz, an interrupt may get lost altogether.
1096 * (usually during an IDE disk interrupt, with IRQ unmasking off)
1097 * Since the interrupt handler doesn't get called, the IRQ status
1098 * byte doesn't get read, and the RTC stops generating interrupts.
1099 * A timer is set, and will call this function if/when that happens.
1100 * To get it out of this stalled state, we just read the status.
1101 * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost.
1102 * (You *really* shouldn't be trying to use a non-realtime system
1103 * for something that requires a steady > 1KHz signal anyways.)
1104 */
1105
1106static void rtc_dropped_irq(unsigned long data)
1107{
1108 unsigned long freq;
1109
1110 spin_lock_irq (&rtc_lock);
1111
1112 if (hpet_rtc_dropped_irq()) {
1113 spin_unlock_irq(&rtc_lock);
1114 return;
1115 }
1116
1117 /* Just in case someone disabled the timer from behind our back... */
1118 if (rtc_status & RTC_TIMER_ON)
1119 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
1120
1121 rtc_irq_data += ((rtc_freq/HZ)<<8);
1122 rtc_irq_data &= ~0xff;
1123 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */
1124
1125 freq = rtc_freq;
1126
1127 spin_unlock_irq(&rtc_lock);
1128
1129 printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", freq);
1130
1131 /* Now we have new data */
1132 wake_up_interruptible(&rtc_wait);
1133
1134 kill_fasync (&rtc_async_queue, SIGIO, POLL_IN);
1135}
1136#endif
1137
1138/*
1139 * Info exported via "/proc/driver/rtc".
1140 */
1141
1142static int rtc_proc_show(struct seq_file *seq, void *v)
1143{
1144#define YN(bit) ((ctrl & bit) ? "yes" : "no")
1145#define NY(bit) ((ctrl & bit) ? "no" : "yes")
1146 struct rtc_time tm;
1147 unsigned char batt, ctrl;
1148 unsigned long freq;
1149
1150 spin_lock_irq(&rtc_lock);
1151 batt = CMOS_READ(RTC_VALID) & RTC_VRT;
1152 ctrl = CMOS_READ(RTC_CONTROL);
1153 freq = rtc_freq;
1154 spin_unlock_irq(&rtc_lock);
1155
1156
1157 rtc_get_rtc_time(&tm);
1158
1159 /*
1160 * There is no way to tell if the luser has the RTC set for local
1161 * time or for Universal Standard Time (GMT). Probably local though.
1162 */
1163 seq_printf(seq,
1164 "rtc_time\t: %02d:%02d:%02d\n"
1165 "rtc_date\t: %04d-%02d-%02d\n"
1166 "rtc_epoch\t: %04lu\n",
1167 tm.tm_hour, tm.tm_min, tm.tm_sec,
1168 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
1169
1170 get_rtc_alm_time(&tm);
1171
1172 /*
1173 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
1174 * match any value for that particular field. Values that are
1175 * greater than a valid time, but less than 0xc0 shouldn't appear.
1176 */
1177 seq_puts(seq, "alarm\t\t: ");
1178 if (tm.tm_hour <= 24)
1179 seq_printf(seq, "%02d:", tm.tm_hour);
1180 else
1181 seq_puts(seq, "**:");
1182
1183 if (tm.tm_min <= 59)
1184 seq_printf(seq, "%02d:", tm.tm_min);
1185 else
1186 seq_puts(seq, "**:");
1187
1188 if (tm.tm_sec <= 59)
1189 seq_printf(seq, "%02d\n", tm.tm_sec);
1190 else
1191 seq_puts(seq, "**\n");
1192
1193 seq_printf(seq,
1194 "DST_enable\t: %s\n"
1195 "BCD\t\t: %s\n"
1196 "24hr\t\t: %s\n"
1197 "square_wave\t: %s\n"
1198 "alarm_IRQ\t: %s\n"
1199 "update_IRQ\t: %s\n"
1200 "periodic_IRQ\t: %s\n"
1201 "periodic_freq\t: %ld\n"
1202 "batt_status\t: %s\n",
1203 YN(RTC_DST_EN),
1204 NY(RTC_DM_BINARY),
1205 YN(RTC_24H),
1206 YN(RTC_SQWE),
1207 YN(RTC_AIE),
1208 YN(RTC_UIE),
1209 YN(RTC_PIE),
1210 freq,
1211 batt ? "okay" : "dead");
1212
1213 return 0;
1214#undef YN
1215#undef NY
1216}
1217
1218static int rtc_proc_open(struct inode *inode, struct file *file)
1219{
1220 return single_open(file, rtc_proc_show, NULL);
1221}
1222
1223void rtc_get_rtc_time(struct rtc_time *rtc_tm)
1224{
Petr Vandrovec403fe5a2005-08-05 15:50:07 +02001225 unsigned long uip_watchdog = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 unsigned char ctrl;
1227#ifdef CONFIG_MACH_DECSTATION
1228 unsigned int real_year;
1229#endif
1230
1231 /*
1232 * read RTC once any update in progress is done. The update
Luca Falavigna47f176f2005-06-28 20:44:42 -07001233 * can take just over 2ms. We wait 20ms. There is no need to
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
1235 * If you need to know *exactly* when a second has started, enable
1236 * periodic update complete interrupts, (via ioctl) and then
1237 * immediately read /dev/rtc which will block until you get the IRQ.
1238 * Once the read clears, read the RTC time (again via ioctl). Easy.
1239 */
1240
Petr Vandrovec403fe5a2005-08-05 15:50:07 +02001241 while (rtc_is_updating() != 0 && jiffies - uip_watchdog < 2*HZ/100) {
1242 barrier();
1243 cpu_relax();
1244 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245
1246 /*
1247 * Only the values that we read from the RTC are set. We leave
Alan Coxb7599582006-01-11 12:17:32 -08001248 * tm_wday, tm_yday and tm_isdst untouched. Note that while the
1249 * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is
1250 * only updated by the RTC when initially set to a non-zero value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 */
1252 spin_lock_irq(&rtc_lock);
1253 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
1254 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
1255 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
1256 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
1257 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
1258 rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
Alan Coxb7599582006-01-11 12:17:32 -08001259 /* Only set from 2.6.16 onwards */
1260 rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK);
1261
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262#ifdef CONFIG_MACH_DECSTATION
1263 real_year = CMOS_READ(RTC_DEC_YEAR);
1264#endif
1265 ctrl = CMOS_READ(RTC_CONTROL);
1266 spin_unlock_irq(&rtc_lock);
1267
1268 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1269 {
1270 BCD_TO_BIN(rtc_tm->tm_sec);
1271 BCD_TO_BIN(rtc_tm->tm_min);
1272 BCD_TO_BIN(rtc_tm->tm_hour);
1273 BCD_TO_BIN(rtc_tm->tm_mday);
1274 BCD_TO_BIN(rtc_tm->tm_mon);
1275 BCD_TO_BIN(rtc_tm->tm_year);
Alan Coxb7599582006-01-11 12:17:32 -08001276 BCD_TO_BIN(rtc_tm->tm_wday);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 }
1278
1279#ifdef CONFIG_MACH_DECSTATION
1280 rtc_tm->tm_year += real_year - 72;
1281#endif
1282
1283 /*
1284 * Account for differences between how the RTC uses the values
1285 * and how they are defined in a struct rtc_time;
1286 */
1287 if ((rtc_tm->tm_year += (epoch - 1900)) <= 69)
1288 rtc_tm->tm_year += 100;
1289
1290 rtc_tm->tm_mon--;
1291}
1292
1293static void get_rtc_alm_time(struct rtc_time *alm_tm)
1294{
1295 unsigned char ctrl;
1296
1297 /*
1298 * Only the values that we read from the RTC are set. That
1299 * means only tm_hour, tm_min, and tm_sec.
1300 */
1301 spin_lock_irq(&rtc_lock);
1302 alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
1303 alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM);
1304 alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM);
1305 ctrl = CMOS_READ(RTC_CONTROL);
1306 spin_unlock_irq(&rtc_lock);
1307
1308 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1309 {
1310 BCD_TO_BIN(alm_tm->tm_sec);
1311 BCD_TO_BIN(alm_tm->tm_min);
1312 BCD_TO_BIN(alm_tm->tm_hour);
1313 }
1314}
1315
1316#ifdef RTC_IRQ
1317/*
1318 * Used to disable/enable interrupts for any one of UIE, AIE, PIE.
1319 * Rumour has it that if you frob the interrupt enable/disable
1320 * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to
1321 * ensure you actually start getting interrupts. Probably for
1322 * compatibility with older/broken chipset RTC implementations.
1323 * We also clear out any old irq data after an ioctl() that
1324 * meddles with the interrupt enable/disable bits.
1325 */
1326
Takashi Iwaic3348762005-11-07 11:14:57 +01001327static void mask_rtc_irq_bit_locked(unsigned char bit)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328{
1329 unsigned char val;
1330
Takashi Iwaic3348762005-11-07 11:14:57 +01001331 if (hpet_mask_rtc_irq_bit(bit))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333 val = CMOS_READ(RTC_CONTROL);
1334 val &= ~bit;
1335 CMOS_WRITE(val, RTC_CONTROL);
1336 CMOS_READ(RTC_INTR_FLAGS);
1337
1338 rtc_irq_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339}
1340
Takashi Iwaic3348762005-11-07 11:14:57 +01001341static void set_rtc_irq_bit_locked(unsigned char bit)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001342{
1343 unsigned char val;
1344
Takashi Iwaic3348762005-11-07 11:14:57 +01001345 if (hpet_set_rtc_irq_bit(bit))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001346 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347 val = CMOS_READ(RTC_CONTROL);
1348 val |= bit;
1349 CMOS_WRITE(val, RTC_CONTROL);
1350 CMOS_READ(RTC_INTR_FLAGS);
1351
1352 rtc_irq_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353}
1354#endif
1355
1356MODULE_AUTHOR("Paul Gortmaker");
1357MODULE_LICENSE("GPL");
1358MODULE_ALIAS_MISCDEV(RTC_MINOR);