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1/*
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
49 * 1.12a Maciej W. Rozycki: Handle memory-mapped chips properly.
50 * 1.12ac Alan Cox: Allow read access to the day of week register
51 * 1.12b David John: Remove calls to the BKL.
52 */
53
54#define RTC_VERSION "1.12b"
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
64#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/sched.h>
78#include <linux/sysctl.h>
79#include <linux/wait.h>
80#include <linux/bcd.h>
81#include <linux/delay.h>
82#include <linux/uaccess.h>
83
84#include <asm/current.h>
85#include <asm/system.h>
86
87#ifdef CONFIG_X86
88#include <asm/hpet.h>
89#endif
90
91#ifdef CONFIG_SPARC32
92#include <linux/of.h>
93#include <linux/of_device.h>
94#include <asm/io.h>
95
96static unsigned long rtc_port;
97static int rtc_irq;
98#endif
99
100#ifdef CONFIG_HPET_EMULATE_RTC
101#undef RTC_IRQ
102#endif
103
104#ifdef RTC_IRQ
105static int rtc_has_irq = 1;
106#endif
107
108#ifndef CONFIG_HPET_EMULATE_RTC
109#define is_hpet_enabled() 0
110#define hpet_set_alarm_time(hrs, min, sec) 0
111#define hpet_set_periodic_freq(arg) 0
112#define hpet_mask_rtc_irq_bit(arg) 0
113#define hpet_set_rtc_irq_bit(arg) 0
114#define hpet_rtc_timer_init() do { } while (0)
115#define hpet_rtc_dropped_irq() 0
116#define hpet_register_irq_handler(h) ({ 0; })
117#define hpet_unregister_irq_handler(h) ({ 0; })
118#ifdef RTC_IRQ
119static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
120{
121 return 0;
122}
123#endif
124#endif
125
126/*
127 * We sponge a minor off of the misc major. No need slurping
128 * up another valuable major dev number for this. If you add
129 * an ioctl, make sure you don't conflict with SPARC's RTC
130 * ioctls.
131 */
132
133static struct fasync_struct *rtc_async_queue;
134
135static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
136
137#ifdef RTC_IRQ
138static void rtc_dropped_irq(unsigned long data);
139
140static DEFINE_TIMER(rtc_irq_timer, rtc_dropped_irq, 0, 0);
141#endif
142
143static ssize_t rtc_read(struct file *file, char __user *buf,
144 size_t count, loff_t *ppos);
145
146static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
147static void rtc_get_rtc_time(struct rtc_time *rtc_tm);
148
149#ifdef RTC_IRQ
150static unsigned int rtc_poll(struct file *file, poll_table *wait);
151#endif
152
153static void get_rtc_alm_time(struct rtc_time *alm_tm);
154#ifdef RTC_IRQ
155static void set_rtc_irq_bit_locked(unsigned char bit);
156static void mask_rtc_irq_bit_locked(unsigned char bit);
157
158static inline void set_rtc_irq_bit(unsigned char bit)
159{
160 spin_lock_irq(&rtc_lock);
161 set_rtc_irq_bit_locked(bit);
162 spin_unlock_irq(&rtc_lock);
163}
164
165static void mask_rtc_irq_bit(unsigned char bit)
166{
167 spin_lock_irq(&rtc_lock);
168 mask_rtc_irq_bit_locked(bit);
169 spin_unlock_irq(&rtc_lock);
170}
171#endif
172
173#ifdef CONFIG_PROC_FS
174static int rtc_proc_open(struct inode *inode, struct file *file);
175#endif
176
177/*
178 * Bits in rtc_status. (6 bits of room for future expansion)
179 */
180
181#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
182#define RTC_TIMER_ON 0x02 /* missed irq timer active */
183
184/*
185 * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is
186 * protected by the spin lock rtc_lock. However, ioctl can still disable the
187 * timer in rtc_status and then with del_timer after the interrupt has read
188 * rtc_status but before mod_timer is called, which would then reenable the
189 * timer (but you would need to have an awful timing before you'd trip on it)
190 */
191static unsigned long rtc_status; /* bitmapped status byte. */
192static unsigned long rtc_freq; /* Current periodic IRQ rate */
193static unsigned long rtc_irq_data; /* our output to the world */
194static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */
195
196#ifdef RTC_IRQ
197/*
198 * rtc_task_lock nests inside rtc_lock.
199 */
200static DEFINE_SPINLOCK(rtc_task_lock);
201static rtc_task_t *rtc_callback;
202#endif
203
204/*
205 * If this driver ever becomes modularised, it will be really nice
206 * to make the epoch retain its value across module reload...
207 */
208
209static unsigned long epoch = 1900; /* year corresponding to 0x00 */
210
211static const unsigned char days_in_mo[] =
212{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
213
214/*
215 * Returns true if a clock update is in progress
216 */
217static inline unsigned char rtc_is_updating(void)
218{
219 unsigned long flags;
220 unsigned char uip;
221
222 spin_lock_irqsave(&rtc_lock, flags);
223 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
224 spin_unlock_irqrestore(&rtc_lock, flags);
225 return uip;
226}
227
228#ifdef RTC_IRQ
229/*
230 * A very tiny interrupt handler. It runs with IRQF_DISABLED set,
231 * but there is possibility of conflicting with the set_rtc_mmss()
232 * call (the rtc irq and the timer irq can easily run at the same
233 * time in two different CPUs). So we need to serialize
234 * accesses to the chip with the rtc_lock spinlock that each
235 * architecture should implement in the timer code.
236 * (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.)
237 */
238
239static irqreturn_t rtc_interrupt(int irq, void *dev_id)
240{
241 /*
242 * Can be an alarm interrupt, update complete interrupt,
243 * or a periodic interrupt. We store the status in the
244 * low byte and the number of interrupts received since
245 * the last read in the remainder of rtc_irq_data.
246 */
247
248 spin_lock(&rtc_lock);
249 rtc_irq_data += 0x100;
250 rtc_irq_data &= ~0xff;
251 if (is_hpet_enabled()) {
252 /*
253 * In this case it is HPET RTC interrupt handler
254 * calling us, with the interrupt information
255 * passed as arg1, instead of irq.
256 */
257 rtc_irq_data |= (unsigned long)irq & 0xF0;
258 } else {
259 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0);
260 }
261
262 if (rtc_status & RTC_TIMER_ON)
263 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
264
265 spin_unlock(&rtc_lock);
266
267 /* Now do the rest of the actions */
268 spin_lock(&rtc_task_lock);
269 if (rtc_callback)
270 rtc_callback->func(rtc_callback->private_data);
271 spin_unlock(&rtc_task_lock);
272 wake_up_interruptible(&rtc_wait);
273
274 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
275
276 return IRQ_HANDLED;
277}
278#endif
279
280/*
281 * sysctl-tuning infrastructure.
282 */
283static ctl_table rtc_table[] = {
284 {
285 .procname = "max-user-freq",
286 .data = &rtc_max_user_freq,
287 .maxlen = sizeof(int),
288 .mode = 0644,
289 .proc_handler = proc_dointvec,
290 },
291 { }
292};
293
294static ctl_table rtc_root[] = {
295 {
296 .procname = "rtc",
297 .mode = 0555,
298 .child = rtc_table,
299 },
300 { }
301};
302
303static ctl_table dev_root[] = {
304 {
305 .procname = "dev",
306 .mode = 0555,
307 .child = rtc_root,
308 },
309 { }
310};
311
312static struct ctl_table_header *sysctl_header;
313
314static int __init init_sysctl(void)
315{
316 sysctl_header = register_sysctl_table(dev_root);
317 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
342 /*
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))
351 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
381 if (count == sizeof(unsigned int)) {
382 retval = put_user(data,
383 (unsigned int __user *)buf) ?: sizeof(int);
384 } else {
385 retval = put_user(data,
386 (unsigned long __user *)buf) ?: sizeof(long);
387 }
388 if (!retval)
389 retval = count;
390 out:
391 __set_current_state(TASK_RUNNING);
392 remove_wait_queue(&rtc_wait, &wait);
393
394 return retval;
395#endif
396}
397
398static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
399{
400 struct rtc_time wtime;
401
402#ifdef RTC_IRQ
403 if (rtc_has_irq == 0) {
404 switch (cmd) {
405 case RTC_AIE_OFF:
406 case RTC_AIE_ON:
407 case RTC_PIE_OFF:
408 case RTC_PIE_ON:
409 case RTC_UIE_OFF:
410 case RTC_UIE_ON:
411 case RTC_IRQP_READ:
412 case RTC_IRQP_SET:
413 return -EINVAL;
414 };
415 }
416#endif
417
418 switch (cmd) {
419#ifdef RTC_IRQ
420 case RTC_AIE_OFF: /* Mask alarm int. enab. bit */
421 {
422 mask_rtc_irq_bit(RTC_AIE);
423 return 0;
424 }
425 case RTC_AIE_ON: /* Allow alarm interrupts. */
426 {
427 set_rtc_irq_bit(RTC_AIE);
428 return 0;
429 }
430 case RTC_PIE_OFF: /* Mask periodic int. enab. bit */
431 {
432 /* can be called from isr via rtc_control() */
433 unsigned long flags;
434
435 spin_lock_irqsave(&rtc_lock, flags);
436 mask_rtc_irq_bit_locked(RTC_PIE);
437 if (rtc_status & RTC_TIMER_ON) {
438 rtc_status &= ~RTC_TIMER_ON;
439 del_timer(&rtc_irq_timer);
440 }
441 spin_unlock_irqrestore(&rtc_lock, flags);
442
443 return 0;
444 }
445 case RTC_PIE_ON: /* Allow periodic ints */
446 {
447 /* can be called from isr via rtc_control() */
448 unsigned long flags;
449
450 /*
451 * We don't really want Joe User enabling more
452 * than 64Hz of interrupts on a multi-user machine.
453 */
454 if (!kernel && (rtc_freq > rtc_max_user_freq) &&
455 (!capable(CAP_SYS_RESOURCE)))
456 return -EACCES;
457
458 spin_lock_irqsave(&rtc_lock, flags);
459 if (!(rtc_status & RTC_TIMER_ON)) {
460 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq +
461 2*HZ/100);
462 rtc_status |= RTC_TIMER_ON;
463 }
464 set_rtc_irq_bit_locked(RTC_PIE);
465 spin_unlock_irqrestore(&rtc_lock, flags);
466
467 return 0;
468 }
469 case RTC_UIE_OFF: /* Mask ints from RTC updates. */
470 {
471 mask_rtc_irq_bit(RTC_UIE);
472 return 0;
473 }
474 case RTC_UIE_ON: /* Allow ints for RTC updates. */
475 {
476 set_rtc_irq_bit(RTC_UIE);
477 return 0;
478 }
479#endif
480 case RTC_ALM_READ: /* Read the present alarm time */
481 {
482 /*
483 * This returns a struct rtc_time. Reading >= 0xc0
484 * means "don't care" or "match all". Only the tm_hour,
485 * tm_min, and tm_sec values are filled in.
486 */
487 memset(&wtime, 0, sizeof(struct rtc_time));
488 get_rtc_alm_time(&wtime);
489 break;
490 }
491 case RTC_ALM_SET: /* Store a time into the alarm */
492 {
493 /*
494 * This expects a struct rtc_time. Writing 0xff means
495 * "don't care" or "match all". Only the tm_hour,
496 * tm_min and tm_sec are used.
497 */
498 unsigned char hrs, min, sec;
499 struct rtc_time alm_tm;
500
501 if (copy_from_user(&alm_tm, (struct rtc_time __user *)arg,
502 sizeof(struct rtc_time)))
503 return -EFAULT;
504
505 hrs = alm_tm.tm_hour;
506 min = alm_tm.tm_min;
507 sec = alm_tm.tm_sec;
508
509 spin_lock_irq(&rtc_lock);
510 if (hpet_set_alarm_time(hrs, min, sec)) {
511 /*
512 * Fallthru and set alarm time in CMOS too,
513 * so that we will get proper value in RTC_ALM_READ
514 */
515 }
516 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) ||
517 RTC_ALWAYS_BCD) {
518 if (sec < 60)
519 sec = bin2bcd(sec);
520 else
521 sec = 0xff;
522
523 if (min < 60)
524 min = bin2bcd(min);
525 else
526 min = 0xff;
527
528 if (hrs < 24)
529 hrs = bin2bcd(hrs);
530 else
531 hrs = 0xff;
532 }
533 CMOS_WRITE(hrs, RTC_HOURS_ALARM);
534 CMOS_WRITE(min, RTC_MINUTES_ALARM);
535 CMOS_WRITE(sec, RTC_SECONDS_ALARM);
536 spin_unlock_irq(&rtc_lock);
537
538 return 0;
539 }
540 case RTC_RD_TIME: /* Read the time/date from RTC */
541 {
542 memset(&wtime, 0, sizeof(struct rtc_time));
543 rtc_get_rtc_time(&wtime);
544 break;
545 }
546 case RTC_SET_TIME: /* Set the RTC */
547 {
548 struct rtc_time rtc_tm;
549 unsigned char mon, day, hrs, min, sec, leap_yr;
550 unsigned char save_control, save_freq_select;
551 unsigned int yrs;
552#ifdef CONFIG_MACH_DECSTATION
553 unsigned int real_yrs;
554#endif
555
556 if (!capable(CAP_SYS_TIME))
557 return -EACCES;
558
559 if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg,
560 sizeof(struct rtc_time)))
561 return -EFAULT;
562
563 yrs = rtc_tm.tm_year + 1900;
564 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
565 day = rtc_tm.tm_mday;
566 hrs = rtc_tm.tm_hour;
567 min = rtc_tm.tm_min;
568 sec = rtc_tm.tm_sec;
569
570 if (yrs < 1970)
571 return -EINVAL;
572
573 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
574
575 if ((mon > 12) || (day == 0))
576 return -EINVAL;
577
578 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
579 return -EINVAL;
580
581 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
582 return -EINVAL;
583
584 yrs -= epoch;
585 if (yrs > 255) /* They are unsigned */
586 return -EINVAL;
587
588 spin_lock_irq(&rtc_lock);
589#ifdef CONFIG_MACH_DECSTATION
590 real_yrs = yrs;
591 yrs = 72;
592
593 /*
594 * We want to keep the year set to 73 until March
595 * for non-leap years, so that Feb, 29th is handled
596 * correctly.
597 */
598 if (!leap_yr && mon < 3) {
599 real_yrs--;
600 yrs = 73;
601 }
602#endif
603 /* These limits and adjustments are independent of
604 * whether the chip is in binary mode or not.
605 */
606 if (yrs > 169) {
607 spin_unlock_irq(&rtc_lock);
608 return -EINVAL;
609 }
610 if (yrs >= 100)
611 yrs -= 100;
612
613 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
614 || RTC_ALWAYS_BCD) {
615 sec = bin2bcd(sec);
616 min = bin2bcd(min);
617 hrs = bin2bcd(hrs);
618 day = bin2bcd(day);
619 mon = bin2bcd(mon);
620 yrs = bin2bcd(yrs);
621 }
622
623 save_control = CMOS_READ(RTC_CONTROL);
624 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
625 save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
626 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
627
628#ifdef CONFIG_MACH_DECSTATION
629 CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
630#endif
631 CMOS_WRITE(yrs, RTC_YEAR);
632 CMOS_WRITE(mon, RTC_MONTH);
633 CMOS_WRITE(day, RTC_DAY_OF_MONTH);
634 CMOS_WRITE(hrs, RTC_HOURS);
635 CMOS_WRITE(min, RTC_MINUTES);
636 CMOS_WRITE(sec, RTC_SECONDS);
637
638 CMOS_WRITE(save_control, RTC_CONTROL);
639 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
640
641 spin_unlock_irq(&rtc_lock);
642 return 0;
643 }
644#ifdef RTC_IRQ
645 case RTC_IRQP_READ: /* Read the periodic IRQ rate. */
646 {
647 return put_user(rtc_freq, (unsigned long __user *)arg);
648 }
649 case RTC_IRQP_SET: /* Set periodic IRQ rate. */
650 {
651 int tmp = 0;
652 unsigned char val;
653 /* can be called from isr via rtc_control() */
654 unsigned long flags;
655
656 /*
657 * The max we can do is 8192Hz.
658 */
659 if ((arg < 2) || (arg > 8192))
660 return -EINVAL;
661 /*
662 * We don't really want Joe User generating more
663 * than 64Hz of interrupts on a multi-user machine.
664 */
665 if (!kernel && (arg > rtc_max_user_freq) &&
666 !capable(CAP_SYS_RESOURCE))
667 return -EACCES;
668
669 while (arg > (1<<tmp))
670 tmp++;
671
672 /*
673 * Check that the input was really a power of 2.
674 */
675 if (arg != (1<<tmp))
676 return -EINVAL;
677
678 rtc_freq = arg;
679
680 spin_lock_irqsave(&rtc_lock, flags);
681 if (hpet_set_periodic_freq(arg)) {
682 spin_unlock_irqrestore(&rtc_lock, flags);
683 return 0;
684 }
685
686 val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
687 val |= (16 - tmp);
688 CMOS_WRITE(val, RTC_FREQ_SELECT);
689 spin_unlock_irqrestore(&rtc_lock, flags);
690 return 0;
691 }
692#endif
693 case RTC_EPOCH_READ: /* Read the epoch. */
694 {
695 return put_user(epoch, (unsigned long __user *)arg);
696 }
697 case RTC_EPOCH_SET: /* Set the epoch. */
698 {
699 /*
700 * There were no RTC clocks before 1900.
701 */
702 if (arg < 1900)
703 return -EINVAL;
704
705 if (!capable(CAP_SYS_TIME))
706 return -EACCES;
707
708 epoch = arg;
709 return 0;
710 }
711 default:
712 return -ENOTTY;
713 }
714 return copy_to_user((void __user *)arg,
715 &wtime, sizeof wtime) ? -EFAULT : 0;
716}
717
718static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
719{
720 long ret;
721 ret = rtc_do_ioctl(cmd, arg, 0);
722 return ret;
723}
724
725/*
726 * We enforce only one user at a time here with the open/close.
727 * Also clear the previous interrupt data on an open, and clean
728 * up things on a close.
729 */
730static int rtc_open(struct inode *inode, struct file *file)
731{
732 spin_lock_irq(&rtc_lock);
733
734 if (rtc_status & RTC_IS_OPEN)
735 goto out_busy;
736
737 rtc_status |= RTC_IS_OPEN;
738
739 rtc_irq_data = 0;
740 spin_unlock_irq(&rtc_lock);
741 return 0;
742
743out_busy:
744 spin_unlock_irq(&rtc_lock);
745 return -EBUSY;
746}
747
748static int rtc_fasync(int fd, struct file *filp, int on)
749{
750 return fasync_helper(fd, filp, on, &rtc_async_queue);
751}
752
753static int rtc_release(struct inode *inode, struct file *file)
754{
755#ifdef RTC_IRQ
756 unsigned char tmp;
757
758 if (rtc_has_irq == 0)
759 goto no_irq;
760
761 /*
762 * Turn off all interrupts once the device is no longer
763 * in use, and clear the data.
764 */
765
766 spin_lock_irq(&rtc_lock);
767 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
768 tmp = CMOS_READ(RTC_CONTROL);
769 tmp &= ~RTC_PIE;
770 tmp &= ~RTC_AIE;
771 tmp &= ~RTC_UIE;
772 CMOS_WRITE(tmp, RTC_CONTROL);
773 CMOS_READ(RTC_INTR_FLAGS);
774 }
775 if (rtc_status & RTC_TIMER_ON) {
776 rtc_status &= ~RTC_TIMER_ON;
777 del_timer(&rtc_irq_timer);
778 }
779 spin_unlock_irq(&rtc_lock);
780
781no_irq:
782#endif
783
784 spin_lock_irq(&rtc_lock);
785 rtc_irq_data = 0;
786 rtc_status &= ~RTC_IS_OPEN;
787 spin_unlock_irq(&rtc_lock);
788
789 return 0;
790}
791
792#ifdef RTC_IRQ
793static unsigned int rtc_poll(struct file *file, poll_table *wait)
794{
795 unsigned long l;
796
797 if (rtc_has_irq == 0)
798 return 0;
799
800 poll_wait(file, &rtc_wait, wait);
801
802 spin_lock_irq(&rtc_lock);
803 l = rtc_irq_data;
804 spin_unlock_irq(&rtc_lock);
805
806 if (l != 0)
807 return POLLIN | POLLRDNORM;
808 return 0;
809}
810#endif
811
812int rtc_register(rtc_task_t *task)
813{
814#ifndef RTC_IRQ
815 return -EIO;
816#else
817 if (task == NULL || task->func == NULL)
818 return -EINVAL;
819 spin_lock_irq(&rtc_lock);
820 if (rtc_status & RTC_IS_OPEN) {
821 spin_unlock_irq(&rtc_lock);
822 return -EBUSY;
823 }
824 spin_lock(&rtc_task_lock);
825 if (rtc_callback) {
826 spin_unlock(&rtc_task_lock);
827 spin_unlock_irq(&rtc_lock);
828 return -EBUSY;
829 }
830 rtc_status |= RTC_IS_OPEN;
831 rtc_callback = task;
832 spin_unlock(&rtc_task_lock);
833 spin_unlock_irq(&rtc_lock);
834 return 0;
835#endif
836}
837EXPORT_SYMBOL(rtc_register);
838
839int rtc_unregister(rtc_task_t *task)
840{
841#ifndef RTC_IRQ
842 return -EIO;
843#else
844 unsigned char tmp;
845
846 spin_lock_irq(&rtc_lock);
847 spin_lock(&rtc_task_lock);
848 if (rtc_callback != task) {
849 spin_unlock(&rtc_task_lock);
850 spin_unlock_irq(&rtc_lock);
851 return -ENXIO;
852 }
853 rtc_callback = NULL;
854
855 /* disable controls */
856 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
857 tmp = CMOS_READ(RTC_CONTROL);
858 tmp &= ~RTC_PIE;
859 tmp &= ~RTC_AIE;
860 tmp &= ~RTC_UIE;
861 CMOS_WRITE(tmp, RTC_CONTROL);
862 CMOS_READ(RTC_INTR_FLAGS);
863 }
864 if (rtc_status & RTC_TIMER_ON) {
865 rtc_status &= ~RTC_TIMER_ON;
866 del_timer(&rtc_irq_timer);
867 }
868 rtc_status &= ~RTC_IS_OPEN;
869 spin_unlock(&rtc_task_lock);
870 spin_unlock_irq(&rtc_lock);
871 return 0;
872#endif
873}
874EXPORT_SYMBOL(rtc_unregister);
875
876int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
877{
878#ifndef RTC_IRQ
879 return -EIO;
880#else
881 unsigned long flags;
882 if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET)
883 return -EINVAL;
884 spin_lock_irqsave(&rtc_task_lock, flags);
885 if (rtc_callback != task) {
886 spin_unlock_irqrestore(&rtc_task_lock, flags);
887 return -ENXIO;
888 }
889 spin_unlock_irqrestore(&rtc_task_lock, flags);
890 return rtc_do_ioctl(cmd, arg, 1);
891#endif
892}
893EXPORT_SYMBOL(rtc_control);
894
895/*
896 * The various file operations we support.
897 */
898
899static const struct file_operations rtc_fops = {
900 .owner = THIS_MODULE,
901 .llseek = no_llseek,
902 .read = rtc_read,
903#ifdef RTC_IRQ
904 .poll = rtc_poll,
905#endif
906 .unlocked_ioctl = rtc_ioctl,
907 .open = rtc_open,
908 .release = rtc_release,
909 .fasync = rtc_fasync,
910};
911
912static struct miscdevice rtc_dev = {
913 .minor = RTC_MINOR,
914 .name = "rtc",
915 .fops = &rtc_fops,
916};
917
918#ifdef CONFIG_PROC_FS
919static const struct file_operations rtc_proc_fops = {
920 .owner = THIS_MODULE,
921 .open = rtc_proc_open,
922 .read = seq_read,
923 .llseek = seq_lseek,
924 .release = single_release,
925};
926#endif
927
928static resource_size_t rtc_size;
929
930static struct resource * __init rtc_request_region(resource_size_t size)
931{
932 struct resource *r;
933
934 if (RTC_IOMAPPED)
935 r = request_region(RTC_PORT(0), size, "rtc");
936 else
937 r = request_mem_region(RTC_PORT(0), size, "rtc");
938
939 if (r)
940 rtc_size = size;
941
942 return r;
943}
944
945static void rtc_release_region(void)
946{
947 if (RTC_IOMAPPED)
948 release_region(RTC_PORT(0), rtc_size);
949 else
950 release_mem_region(RTC_PORT(0), rtc_size);
951}
952
953static int __init rtc_init(void)
954{
955#ifdef CONFIG_PROC_FS
956 struct proc_dir_entry *ent;
957#endif
958#if defined(__alpha__) || defined(__mips__)
959 unsigned int year, ctrl;
960 char *guess = NULL;
961#endif
962#ifdef CONFIG_SPARC32
963 struct device_node *ebus_dp;
964 struct platform_device *op;
965#else
966 void *r;
967#ifdef RTC_IRQ
968 irq_handler_t rtc_int_handler_ptr;
969#endif
970#endif
971
972#ifdef CONFIG_SPARC32
973 for_each_node_by_name(ebus_dp, "ebus") {
974 struct device_node *dp;
975 for (dp = ebus_dp; dp; dp = dp->sibling) {
976 if (!strcmp(dp->name, "rtc")) {
977 op = of_find_device_by_node(dp);
978 if (op) {
979 rtc_port = op->resource[0].start;
980 rtc_irq = op->irqs[0];
981 goto found;
982 }
983 }
984 }
985 }
986 rtc_has_irq = 0;
987 printk(KERN_ERR "rtc_init: no PC rtc found\n");
988 return -EIO;
989
990found:
991 if (!rtc_irq) {
992 rtc_has_irq = 0;
993 goto no_irq;
994 }
995
996 /*
997 * XXX Interrupt pin #7 in Espresso is shared between RTC and
998 * PCI Slot 2 INTA# (and some INTx# in Slot 1).
999 */
1000 if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc",
1001 (void *)&rtc_port)) {
1002 rtc_has_irq = 0;
1003 printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq);
1004 return -EIO;
1005 }
1006no_irq:
1007#else
1008 r = rtc_request_region(RTC_IO_EXTENT);
1009
1010 /*
1011 * If we've already requested a smaller range (for example, because
1012 * PNPBIOS or ACPI told us how the device is configured), the request
1013 * above might fail because it's too big.
1014 *
1015 * If so, request just the range we actually use.
1016 */
1017 if (!r)
1018 r = rtc_request_region(RTC_IO_EXTENT_USED);
1019 if (!r) {
1020#ifdef RTC_IRQ
1021 rtc_has_irq = 0;
1022#endif
1023 printk(KERN_ERR "rtc: I/O resource %lx is not free.\n",
1024 (long)(RTC_PORT(0)));
1025 return -EIO;
1026 }
1027
1028#ifdef RTC_IRQ
1029 if (is_hpet_enabled()) {
1030 int err;
1031
1032 rtc_int_handler_ptr = hpet_rtc_interrupt;
1033 err = hpet_register_irq_handler(rtc_interrupt);
1034 if (err != 0) {
1035 printk(KERN_WARNING "hpet_register_irq_handler failed "
1036 "in rtc_init().");
1037 return err;
1038 }
1039 } else {
1040 rtc_int_handler_ptr = rtc_interrupt;
1041 }
1042
1043 if (request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED,
1044 "rtc", NULL)) {
1045 /* Yeah right, seeing as irq 8 doesn't even hit the bus. */
1046 rtc_has_irq = 0;
1047 printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
1048 rtc_release_region();
1049
1050 return -EIO;
1051 }
1052 hpet_rtc_timer_init();
1053
1054#endif
1055
1056#endif /* CONFIG_SPARC32 vs. others */
1057
1058 if (misc_register(&rtc_dev)) {
1059#ifdef RTC_IRQ
1060 free_irq(RTC_IRQ, NULL);
1061 hpet_unregister_irq_handler(rtc_interrupt);
1062 rtc_has_irq = 0;
1063#endif
1064 rtc_release_region();
1065 return -ENODEV;
1066 }
1067
1068#ifdef CONFIG_PROC_FS
1069 ent = proc_create("driver/rtc", 0, NULL, &rtc_proc_fops);
1070 if (!ent)
1071 printk(KERN_WARNING "rtc: Failed to register with procfs.\n");
1072#endif
1073
1074#if defined(__alpha__) || defined(__mips__)
1075 rtc_freq = HZ;
1076
1077 /* Each operating system on an Alpha uses its own epoch.
1078 Let's try to guess which one we are using now. */
1079
1080 if (rtc_is_updating() != 0)
1081 msleep(20);
1082
1083 spin_lock_irq(&rtc_lock);
1084 year = CMOS_READ(RTC_YEAR);
1085 ctrl = CMOS_READ(RTC_CONTROL);
1086 spin_unlock_irq(&rtc_lock);
1087
1088 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1089 year = bcd2bin(year); /* This should never happen... */
1090
1091 if (year < 20) {
1092 epoch = 2000;
1093 guess = "SRM (post-2000)";
1094 } else if (year >= 20 && year < 48) {
1095 epoch = 1980;
1096 guess = "ARC console";
1097 } else if (year >= 48 && year < 72) {
1098 epoch = 1952;
1099 guess = "Digital UNIX";
1100#if defined(__mips__)
1101 } else if (year >= 72 && year < 74) {
1102 epoch = 2000;
1103 guess = "Digital DECstation";
1104#else
1105 } else if (year >= 70) {
1106 epoch = 1900;
1107 guess = "Standard PC (1900)";
1108#endif
1109 }
1110 if (guess)
1111 printk(KERN_INFO "rtc: %s epoch (%lu) detected\n",
1112 guess, epoch);
1113#endif
1114#ifdef RTC_IRQ
1115 if (rtc_has_irq == 0)
1116 goto no_irq2;
1117
1118 spin_lock_irq(&rtc_lock);
1119 rtc_freq = 1024;
1120 if (!hpet_set_periodic_freq(rtc_freq)) {
1121 /*
1122 * Initialize periodic frequency to CMOS reset default,
1123 * which is 1024Hz
1124 */
1125 CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06),
1126 RTC_FREQ_SELECT);
1127 }
1128 spin_unlock_irq(&rtc_lock);
1129no_irq2:
1130#endif
1131
1132 (void) init_sysctl();
1133
1134 printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
1135
1136 return 0;
1137}
1138
1139static void __exit rtc_exit(void)
1140{
1141 cleanup_sysctl();
1142 remove_proc_entry("driver/rtc", NULL);
1143 misc_deregister(&rtc_dev);
1144
1145#ifdef CONFIG_SPARC32
1146 if (rtc_has_irq)
1147 free_irq(rtc_irq, &rtc_port);
1148#else
1149 rtc_release_region();
1150#ifdef RTC_IRQ
1151 if (rtc_has_irq) {
1152 free_irq(RTC_IRQ, NULL);
1153 hpet_unregister_irq_handler(hpet_rtc_interrupt);
1154 }
1155#endif
1156#endif /* CONFIG_SPARC32 */
1157}
1158
1159module_init(rtc_init);
1160module_exit(rtc_exit);
1161
1162#ifdef RTC_IRQ
1163/*
1164 * At IRQ rates >= 4096Hz, an interrupt may get lost altogether.
1165 * (usually during an IDE disk interrupt, with IRQ unmasking off)
1166 * Since the interrupt handler doesn't get called, the IRQ status
1167 * byte doesn't get read, and the RTC stops generating interrupts.
1168 * A timer is set, and will call this function if/when that happens.
1169 * To get it out of this stalled state, we just read the status.
1170 * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost.
1171 * (You *really* shouldn't be trying to use a non-realtime system
1172 * for something that requires a steady > 1KHz signal anyways.)
1173 */
1174
1175static void rtc_dropped_irq(unsigned long data)
1176{
1177 unsigned long freq;
1178
1179 spin_lock_irq(&rtc_lock);
1180
1181 if (hpet_rtc_dropped_irq()) {
1182 spin_unlock_irq(&rtc_lock);
1183 return;
1184 }
1185
1186 /* Just in case someone disabled the timer from behind our back... */
1187 if (rtc_status & RTC_TIMER_ON)
1188 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
1189
1190 rtc_irq_data += ((rtc_freq/HZ)<<8);
1191 rtc_irq_data &= ~0xff;
1192 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */
1193
1194 freq = rtc_freq;
1195
1196 spin_unlock_irq(&rtc_lock);
1197
1198 if (printk_ratelimit()) {
1199 printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n",
1200 freq);
1201 }
1202
1203 /* Now we have new data */
1204 wake_up_interruptible(&rtc_wait);
1205
1206 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
1207}
1208#endif
1209
1210#ifdef CONFIG_PROC_FS
1211/*
1212 * Info exported via "/proc/driver/rtc".
1213 */
1214
1215static int rtc_proc_show(struct seq_file *seq, void *v)
1216{
1217#define YN(bit) ((ctrl & bit) ? "yes" : "no")
1218#define NY(bit) ((ctrl & bit) ? "no" : "yes")
1219 struct rtc_time tm;
1220 unsigned char batt, ctrl;
1221 unsigned long freq;
1222
1223 spin_lock_irq(&rtc_lock);
1224 batt = CMOS_READ(RTC_VALID) & RTC_VRT;
1225 ctrl = CMOS_READ(RTC_CONTROL);
1226 freq = rtc_freq;
1227 spin_unlock_irq(&rtc_lock);
1228
1229
1230 rtc_get_rtc_time(&tm);
1231
1232 /*
1233 * There is no way to tell if the luser has the RTC set for local
1234 * time or for Universal Standard Time (GMT). Probably local though.
1235 */
1236 seq_printf(seq,
1237 "rtc_time\t: %02d:%02d:%02d\n"
1238 "rtc_date\t: %04d-%02d-%02d\n"
1239 "rtc_epoch\t: %04lu\n",
1240 tm.tm_hour, tm.tm_min, tm.tm_sec,
1241 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
1242
1243 get_rtc_alm_time(&tm);
1244
1245 /*
1246 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
1247 * match any value for that particular field. Values that are
1248 * greater than a valid time, but less than 0xc0 shouldn't appear.
1249 */
1250 seq_puts(seq, "alarm\t\t: ");
1251 if (tm.tm_hour <= 24)
1252 seq_printf(seq, "%02d:", tm.tm_hour);
1253 else
1254 seq_puts(seq, "**:");
1255
1256 if (tm.tm_min <= 59)
1257 seq_printf(seq, "%02d:", tm.tm_min);
1258 else
1259 seq_puts(seq, "**:");
1260
1261 if (tm.tm_sec <= 59)
1262 seq_printf(seq, "%02d\n", tm.tm_sec);
1263 else
1264 seq_puts(seq, "**\n");
1265
1266 seq_printf(seq,
1267 "DST_enable\t: %s\n"
1268 "BCD\t\t: %s\n"
1269 "24hr\t\t: %s\n"
1270 "square_wave\t: %s\n"
1271 "alarm_IRQ\t: %s\n"
1272 "update_IRQ\t: %s\n"
1273 "periodic_IRQ\t: %s\n"
1274 "periodic_freq\t: %ld\n"
1275 "batt_status\t: %s\n",
1276 YN(RTC_DST_EN),
1277 NY(RTC_DM_BINARY),
1278 YN(RTC_24H),
1279 YN(RTC_SQWE),
1280 YN(RTC_AIE),
1281 YN(RTC_UIE),
1282 YN(RTC_PIE),
1283 freq,
1284 batt ? "okay" : "dead");
1285
1286 return 0;
1287#undef YN
1288#undef NY
1289}
1290
1291static int rtc_proc_open(struct inode *inode, struct file *file)
1292{
1293 return single_open(file, rtc_proc_show, NULL);
1294}
1295#endif
1296
1297static void rtc_get_rtc_time(struct rtc_time *rtc_tm)
1298{
1299 unsigned long uip_watchdog = jiffies, flags;
1300 unsigned char ctrl;
1301#ifdef CONFIG_MACH_DECSTATION
1302 unsigned int real_year;
1303#endif
1304
1305 /*
1306 * read RTC once any update in progress is done. The update
1307 * can take just over 2ms. We wait 20ms. There is no need to
1308 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
1309 * If you need to know *exactly* when a second has started, enable
1310 * periodic update complete interrupts, (via ioctl) and then
1311 * immediately read /dev/rtc which will block until you get the IRQ.
1312 * Once the read clears, read the RTC time (again via ioctl). Easy.
1313 */
1314
1315 while (rtc_is_updating() != 0 &&
1316 time_before(jiffies, uip_watchdog + 2*HZ/100))
1317 cpu_relax();
1318
1319 /*
1320 * Only the values that we read from the RTC are set. We leave
1321 * tm_wday, tm_yday and tm_isdst untouched. Note that while the
1322 * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is
1323 * only updated by the RTC when initially set to a non-zero value.
1324 */
1325 spin_lock_irqsave(&rtc_lock, flags);
1326 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
1327 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
1328 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
1329 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
1330 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
1331 rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
1332 /* Only set from 2.6.16 onwards */
1333 rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK);
1334
1335#ifdef CONFIG_MACH_DECSTATION
1336 real_year = CMOS_READ(RTC_DEC_YEAR);
1337#endif
1338 ctrl = CMOS_READ(RTC_CONTROL);
1339 spin_unlock_irqrestore(&rtc_lock, flags);
1340
1341 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
1342 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
1343 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
1344 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
1345 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
1346 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
1347 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
1348 rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
1349 }
1350
1351#ifdef CONFIG_MACH_DECSTATION
1352 rtc_tm->tm_year += real_year - 72;
1353#endif
1354
1355 /*
1356 * Account for differences between how the RTC uses the values
1357 * and how they are defined in a struct rtc_time;
1358 */
1359 rtc_tm->tm_year += epoch - 1900;
1360 if (rtc_tm->tm_year <= 69)
1361 rtc_tm->tm_year += 100;
1362
1363 rtc_tm->tm_mon--;
1364}
1365
1366static void get_rtc_alm_time(struct rtc_time *alm_tm)
1367{
1368 unsigned char ctrl;
1369
1370 /*
1371 * Only the values that we read from the RTC are set. That
1372 * means only tm_hour, tm_min, and tm_sec.
1373 */
1374 spin_lock_irq(&rtc_lock);
1375 alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
1376 alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM);
1377 alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM);
1378 ctrl = CMOS_READ(RTC_CONTROL);
1379 spin_unlock_irq(&rtc_lock);
1380
1381 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
1382 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
1383 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
1384 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
1385 }
1386}
1387
1388#ifdef RTC_IRQ
1389/*
1390 * Used to disable/enable interrupts for any one of UIE, AIE, PIE.
1391 * Rumour has it that if you frob the interrupt enable/disable
1392 * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to
1393 * ensure you actually start getting interrupts. Probably for
1394 * compatibility with older/broken chipset RTC implementations.
1395 * We also clear out any old irq data after an ioctl() that
1396 * meddles with the interrupt enable/disable bits.
1397 */
1398
1399static void mask_rtc_irq_bit_locked(unsigned char bit)
1400{
1401 unsigned char val;
1402
1403 if (hpet_mask_rtc_irq_bit(bit))
1404 return;
1405 val = CMOS_READ(RTC_CONTROL);
1406 val &= ~bit;
1407 CMOS_WRITE(val, RTC_CONTROL);
1408 CMOS_READ(RTC_INTR_FLAGS);
1409
1410 rtc_irq_data = 0;
1411}
1412
1413static void set_rtc_irq_bit_locked(unsigned char bit)
1414{
1415 unsigned char val;
1416
1417 if (hpet_set_rtc_irq_bit(bit))
1418 return;
1419 val = CMOS_READ(RTC_CONTROL);
1420 val |= bit;
1421 CMOS_WRITE(val, RTC_CONTROL);
1422 CMOS_READ(RTC_INTR_FLAGS);
1423
1424 rtc_irq_data = 0;
1425}
1426#endif
1427
1428MODULE_AUTHOR("Paul Gortmaker");
1429MODULE_LICENSE("GPL");
1430MODULE_ALIAS_MISCDEV(RTC_MINOR);