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/sysctl.h>
78 #include <linux/wait.h>
79 #include <linux/bcd.h>
80 #include <linux/delay.h>
81 #include <linux/uaccess.h>
82
83 #include <asm/current.h>
84 #include <asm/system.h>
85
86 #ifdef CONFIG_X86
87 #include <asm/hpet.h>
88 #endif
89
90 #ifdef CONFIG_SPARC32
91 #include <linux/of.h>
92 #include <linux/of_device.h>
93 #include <asm/io.h>
94
95 static unsigned long rtc_port;
96 static int rtc_irq;
97 #endif
98
99 #ifdef CONFIG_HPET_EMULATE_RTC
100 #undef RTC_IRQ
101 #endif
102
103 #ifdef RTC_IRQ
104 static int rtc_has_irq = 1;
105 #endif
106
107 #ifndef CONFIG_HPET_EMULATE_RTC
108 #define is_hpet_enabled() 0
109 #define hpet_set_alarm_time(hrs, min, sec) 0
110 #define hpet_set_periodic_freq(arg) 0
111 #define hpet_mask_rtc_irq_bit(arg) 0
112 #define hpet_set_rtc_irq_bit(arg) 0
113 #define hpet_rtc_timer_init() do { } while (0)
114 #define hpet_rtc_dropped_irq() 0
115 #define hpet_register_irq_handler(h) ({ 0; })
116 #define hpet_unregister_irq_handler(h) ({ 0; })
117 #ifdef RTC_IRQ
hpet_rtc_interrupt(int irq,void * dev_id)118 static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
119 {
120 return 0;
121 }
122 #endif
123 #endif
124
125 /*
126 * We sponge a minor off of the misc major. No need slurping
127 * up another valuable major dev number for this. If you add
128 * an ioctl, make sure you don't conflict with SPARC's RTC
129 * ioctls.
130 */
131
132 static struct fasync_struct *rtc_async_queue;
133
134 static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
135
136 #ifdef RTC_IRQ
137 static void rtc_dropped_irq(unsigned long data);
138
139 static DEFINE_TIMER(rtc_irq_timer, rtc_dropped_irq, 0, 0);
140 #endif
141
142 static ssize_t rtc_read(struct file *file, char __user *buf,
143 size_t count, loff_t *ppos);
144
145 static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
146 static void rtc_get_rtc_time(struct rtc_time *rtc_tm);
147
148 #ifdef RTC_IRQ
149 static unsigned int rtc_poll(struct file *file, poll_table *wait);
150 #endif
151
152 static void get_rtc_alm_time(struct rtc_time *alm_tm);
153 #ifdef RTC_IRQ
154 static void set_rtc_irq_bit_locked(unsigned char bit);
155 static void mask_rtc_irq_bit_locked(unsigned char bit);
156
set_rtc_irq_bit(unsigned char bit)157 static inline void set_rtc_irq_bit(unsigned char bit)
158 {
159 spin_lock_irq(&rtc_lock);
160 set_rtc_irq_bit_locked(bit);
161 spin_unlock_irq(&rtc_lock);
162 }
163
mask_rtc_irq_bit(unsigned char bit)164 static void mask_rtc_irq_bit(unsigned char bit)
165 {
166 spin_lock_irq(&rtc_lock);
167 mask_rtc_irq_bit_locked(bit);
168 spin_unlock_irq(&rtc_lock);
169 }
170 #endif
171
172 #ifdef CONFIG_PROC_FS
173 static int rtc_proc_open(struct inode *inode, struct file *file);
174 #endif
175
176 /*
177 * Bits in rtc_status. (6 bits of room for future expansion)
178 */
179
180 #define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
181 #define RTC_TIMER_ON 0x02 /* missed irq timer active */
182
183 /*
184 * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is
185 * protected by the spin lock rtc_lock. However, ioctl can still disable the
186 * timer in rtc_status and then with del_timer after the interrupt has read
187 * rtc_status but before mod_timer is called, which would then reenable the
188 * timer (but you would need to have an awful timing before you'd trip on it)
189 */
190 static unsigned long rtc_status; /* bitmapped status byte. */
191 static unsigned long rtc_freq; /* Current periodic IRQ rate */
192 static unsigned long rtc_irq_data; /* our output to the world */
193 static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */
194
195 #ifdef RTC_IRQ
196 /*
197 * rtc_task_lock nests inside rtc_lock.
198 */
199 static DEFINE_SPINLOCK(rtc_task_lock);
200 static rtc_task_t *rtc_callback;
201 #endif
202
203 /*
204 * If this driver ever becomes modularised, it will be really nice
205 * to make the epoch retain its value across module reload...
206 */
207
208 static unsigned long epoch = 1900; /* year corresponding to 0x00 */
209
210 static const unsigned char days_in_mo[] =
211 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
212
213 /*
214 * Returns true if a clock update is in progress
215 */
rtc_is_updating(void)216 static inline unsigned char rtc_is_updating(void)
217 {
218 unsigned long flags;
219 unsigned char uip;
220
221 spin_lock_irqsave(&rtc_lock, flags);
222 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
223 spin_unlock_irqrestore(&rtc_lock, flags);
224 return uip;
225 }
226
227 #ifdef RTC_IRQ
228 /*
229 * A very tiny interrupt handler. It runs with IRQF_DISABLED set,
230 * but there is possibility of conflicting with the set_rtc_mmss()
231 * call (the rtc irq and the timer irq can easily run at the same
232 * time in two different CPUs). So we need to serialize
233 * accesses to the chip with the rtc_lock spinlock that each
234 * architecture should implement in the timer code.
235 * (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.)
236 */
237
rtc_interrupt(int irq,void * dev_id)238 static irqreturn_t rtc_interrupt(int irq, void *dev_id)
239 {
240 /*
241 * Can be an alarm interrupt, update complete interrupt,
242 * or a periodic interrupt. We store the status in the
243 * low byte and the number of interrupts received since
244 * the last read in the remainder of rtc_irq_data.
245 */
246
247 spin_lock(&rtc_lock);
248 rtc_irq_data += 0x100;
249 rtc_irq_data &= ~0xff;
250 if (is_hpet_enabled()) {
251 /*
252 * In this case it is HPET RTC interrupt handler
253 * calling us, with the interrupt information
254 * passed as arg1, instead of irq.
255 */
256 rtc_irq_data |= (unsigned long)irq & 0xF0;
257 } else {
258 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0);
259 }
260
261 if (rtc_status & RTC_TIMER_ON)
262 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
263
264 spin_unlock(&rtc_lock);
265
266 /* Now do the rest of the actions */
267 spin_lock(&rtc_task_lock);
268 if (rtc_callback)
269 rtc_callback->func(rtc_callback->private_data);
270 spin_unlock(&rtc_task_lock);
271 wake_up_interruptible(&rtc_wait);
272
273 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
274
275 return IRQ_HANDLED;
276 }
277 #endif
278
279 /*
280 * sysctl-tuning infrastructure.
281 */
282 static ctl_table rtc_table[] = {
283 {
284 .ctl_name = CTL_UNNUMBERED,
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 { .ctl_name = 0 }
292 };
293
294 static ctl_table rtc_root[] = {
295 {
296 .ctl_name = CTL_UNNUMBERED,
297 .procname = "rtc",
298 .mode = 0555,
299 .child = rtc_table,
300 },
301 { .ctl_name = 0 }
302 };
303
304 static ctl_table dev_root[] = {
305 {
306 .ctl_name = CTL_DEV,
307 .procname = "dev",
308 .mode = 0555,
309 .child = rtc_root,
310 },
311 { .ctl_name = 0 }
312 };
313
314 static struct ctl_table_header *sysctl_header;
315
init_sysctl(void)316 static int __init init_sysctl(void)
317 {
318 sysctl_header = register_sysctl_table(dev_root);
319 return 0;
320 }
321
cleanup_sysctl(void)322 static void __exit cleanup_sysctl(void)
323 {
324 unregister_sysctl_table(sysctl_header);
325 }
326
327 /*
328 * Now all the various file operations that we export.
329 */
330
rtc_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)331 static ssize_t rtc_read(struct file *file, char __user *buf,
332 size_t count, loff_t *ppos)
333 {
334 #ifndef RTC_IRQ
335 return -EIO;
336 #else
337 DECLARE_WAITQUEUE(wait, current);
338 unsigned long data;
339 ssize_t retval;
340
341 if (rtc_has_irq == 0)
342 return -EIO;
343
344 /*
345 * Historically this function used to assume that sizeof(unsigned long)
346 * is the same in userspace and kernelspace. This lead to problems
347 * for configurations with multiple ABIs such a the MIPS o32 and 64
348 * ABIs supported on the same kernel. So now we support read of both
349 * 4 and 8 bytes and assume that's the sizeof(unsigned long) in the
350 * userspace ABI.
351 */
352 if (count != sizeof(unsigned int) && count != sizeof(unsigned long))
353 return -EINVAL;
354
355 add_wait_queue(&rtc_wait, &wait);
356
357 do {
358 /* First make it right. Then make it fast. Putting this whole
359 * block within the parentheses of a while would be too
360 * confusing. And no, xchg() is not the answer. */
361
362 __set_current_state(TASK_INTERRUPTIBLE);
363
364 spin_lock_irq(&rtc_lock);
365 data = rtc_irq_data;
366 rtc_irq_data = 0;
367 spin_unlock_irq(&rtc_lock);
368
369 if (data != 0)
370 break;
371
372 if (file->f_flags & O_NONBLOCK) {
373 retval = -EAGAIN;
374 goto out;
375 }
376 if (signal_pending(current)) {
377 retval = -ERESTARTSYS;
378 goto out;
379 }
380 schedule();
381 } while (1);
382
383 if (count == sizeof(unsigned int)) {
384 retval = put_user(data,
385 (unsigned int __user *)buf) ?: sizeof(int);
386 } else {
387 retval = put_user(data,
388 (unsigned long __user *)buf) ?: sizeof(long);
389 }
390 if (!retval)
391 retval = count;
392 out:
393 __set_current_state(TASK_RUNNING);
394 remove_wait_queue(&rtc_wait, &wait);
395
396 return retval;
397 #endif
398 }
399
rtc_do_ioctl(unsigned int cmd,unsigned long arg,int kernel)400 static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
401 {
402 struct rtc_time wtime;
403
404 #ifdef RTC_IRQ
405 if (rtc_has_irq == 0) {
406 switch (cmd) {
407 case RTC_AIE_OFF:
408 case RTC_AIE_ON:
409 case RTC_PIE_OFF:
410 case RTC_PIE_ON:
411 case RTC_UIE_OFF:
412 case RTC_UIE_ON:
413 case RTC_IRQP_READ:
414 case RTC_IRQP_SET:
415 return -EINVAL;
416 };
417 }
418 #endif
419
420 switch (cmd) {
421 #ifdef RTC_IRQ
422 case RTC_AIE_OFF: /* Mask alarm int. enab. bit */
423 {
424 mask_rtc_irq_bit(RTC_AIE);
425 return 0;
426 }
427 case RTC_AIE_ON: /* Allow alarm interrupts. */
428 {
429 set_rtc_irq_bit(RTC_AIE);
430 return 0;
431 }
432 case RTC_PIE_OFF: /* Mask periodic int. enab. bit */
433 {
434 /* can be called from isr via rtc_control() */
435 unsigned long flags;
436
437 spin_lock_irqsave(&rtc_lock, flags);
438 mask_rtc_irq_bit_locked(RTC_PIE);
439 if (rtc_status & RTC_TIMER_ON) {
440 rtc_status &= ~RTC_TIMER_ON;
441 del_timer(&rtc_irq_timer);
442 }
443 spin_unlock_irqrestore(&rtc_lock, flags);
444
445 return 0;
446 }
447 case RTC_PIE_ON: /* Allow periodic ints */
448 {
449 /* can be called from isr via rtc_control() */
450 unsigned long flags;
451
452 /*
453 * We don't really want Joe User enabling more
454 * than 64Hz of interrupts on a multi-user machine.
455 */
456 if (!kernel && (rtc_freq > rtc_max_user_freq) &&
457 (!capable(CAP_SYS_RESOURCE)))
458 return -EACCES;
459
460 spin_lock_irqsave(&rtc_lock, flags);
461 if (!(rtc_status & RTC_TIMER_ON)) {
462 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq +
463 2*HZ/100);
464 rtc_status |= RTC_TIMER_ON;
465 }
466 set_rtc_irq_bit_locked(RTC_PIE);
467 spin_unlock_irqrestore(&rtc_lock, flags);
468
469 return 0;
470 }
471 case RTC_UIE_OFF: /* Mask ints from RTC updates. */
472 {
473 mask_rtc_irq_bit(RTC_UIE);
474 return 0;
475 }
476 case RTC_UIE_ON: /* Allow ints for RTC updates. */
477 {
478 set_rtc_irq_bit(RTC_UIE);
479 return 0;
480 }
481 #endif
482 case RTC_ALM_READ: /* Read the present alarm time */
483 {
484 /*
485 * This returns a struct rtc_time. Reading >= 0xc0
486 * means "don't care" or "match all". Only the tm_hour,
487 * tm_min, and tm_sec values are filled in.
488 */
489 memset(&wtime, 0, sizeof(struct rtc_time));
490 get_rtc_alm_time(&wtime);
491 break;
492 }
493 case RTC_ALM_SET: /* Store a time into the alarm */
494 {
495 /*
496 * This expects a struct rtc_time. Writing 0xff means
497 * "don't care" or "match all". Only the tm_hour,
498 * tm_min and tm_sec are used.
499 */
500 unsigned char hrs, min, sec;
501 struct rtc_time alm_tm;
502
503 if (copy_from_user(&alm_tm, (struct rtc_time __user *)arg,
504 sizeof(struct rtc_time)))
505 return -EFAULT;
506
507 hrs = alm_tm.tm_hour;
508 min = alm_tm.tm_min;
509 sec = alm_tm.tm_sec;
510
511 spin_lock_irq(&rtc_lock);
512 if (hpet_set_alarm_time(hrs, min, sec)) {
513 /*
514 * Fallthru and set alarm time in CMOS too,
515 * so that we will get proper value in RTC_ALM_READ
516 */
517 }
518 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) ||
519 RTC_ALWAYS_BCD) {
520 if (sec < 60)
521 sec = bin2bcd(sec);
522 else
523 sec = 0xff;
524
525 if (min < 60)
526 min = bin2bcd(min);
527 else
528 min = 0xff;
529
530 if (hrs < 24)
531 hrs = bin2bcd(hrs);
532 else
533 hrs = 0xff;
534 }
535 CMOS_WRITE(hrs, RTC_HOURS_ALARM);
536 CMOS_WRITE(min, RTC_MINUTES_ALARM);
537 CMOS_WRITE(sec, RTC_SECONDS_ALARM);
538 spin_unlock_irq(&rtc_lock);
539
540 return 0;
541 }
542 case RTC_RD_TIME: /* Read the time/date from RTC */
543 {
544 memset(&wtime, 0, sizeof(struct rtc_time));
545 rtc_get_rtc_time(&wtime);
546 break;
547 }
548 case RTC_SET_TIME: /* Set the RTC */
549 {
550 struct rtc_time rtc_tm;
551 unsigned char mon, day, hrs, min, sec, leap_yr;
552 unsigned char save_control, save_freq_select;
553 unsigned int yrs;
554 #ifdef CONFIG_MACH_DECSTATION
555 unsigned int real_yrs;
556 #endif
557
558 if (!capable(CAP_SYS_TIME))
559 return -EACCES;
560
561 if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg,
562 sizeof(struct rtc_time)))
563 return -EFAULT;
564
565 yrs = rtc_tm.tm_year + 1900;
566 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
567 day = rtc_tm.tm_mday;
568 hrs = rtc_tm.tm_hour;
569 min = rtc_tm.tm_min;
570 sec = rtc_tm.tm_sec;
571
572 if (yrs < 1970)
573 return -EINVAL;
574
575 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
576
577 if ((mon > 12) || (day == 0))
578 return -EINVAL;
579
580 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
581 return -EINVAL;
582
583 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
584 return -EINVAL;
585
586 yrs -= epoch;
587 if (yrs > 255) /* They are unsigned */
588 return -EINVAL;
589
590 spin_lock_irq(&rtc_lock);
591 #ifdef CONFIG_MACH_DECSTATION
592 real_yrs = yrs;
593 yrs = 72;
594
595 /*
596 * We want to keep the year set to 73 until March
597 * for non-leap years, so that Feb, 29th is handled
598 * correctly.
599 */
600 if (!leap_yr && mon < 3) {
601 real_yrs--;
602 yrs = 73;
603 }
604 #endif
605 /* These limits and adjustments are independent of
606 * whether the chip is in binary mode or not.
607 */
608 if (yrs > 169) {
609 spin_unlock_irq(&rtc_lock);
610 return -EINVAL;
611 }
612 if (yrs >= 100)
613 yrs -= 100;
614
615 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
616 || RTC_ALWAYS_BCD) {
617 sec = bin2bcd(sec);
618 min = bin2bcd(min);
619 hrs = bin2bcd(hrs);
620 day = bin2bcd(day);
621 mon = bin2bcd(mon);
622 yrs = bin2bcd(yrs);
623 }
624
625 save_control = CMOS_READ(RTC_CONTROL);
626 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
627 save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
628 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
629
630 #ifdef CONFIG_MACH_DECSTATION
631 CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
632 #endif
633 CMOS_WRITE(yrs, RTC_YEAR);
634 CMOS_WRITE(mon, RTC_MONTH);
635 CMOS_WRITE(day, RTC_DAY_OF_MONTH);
636 CMOS_WRITE(hrs, RTC_HOURS);
637 CMOS_WRITE(min, RTC_MINUTES);
638 CMOS_WRITE(sec, RTC_SECONDS);
639
640 CMOS_WRITE(save_control, RTC_CONTROL);
641 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
642
643 spin_unlock_irq(&rtc_lock);
644 return 0;
645 }
646 #ifdef RTC_IRQ
647 case RTC_IRQP_READ: /* Read the periodic IRQ rate. */
648 {
649 return put_user(rtc_freq, (unsigned long __user *)arg);
650 }
651 case RTC_IRQP_SET: /* Set periodic IRQ rate. */
652 {
653 int tmp = 0;
654 unsigned char val;
655 /* can be called from isr via rtc_control() */
656 unsigned long flags;
657
658 /*
659 * The max we can do is 8192Hz.
660 */
661 if ((arg < 2) || (arg > 8192))
662 return -EINVAL;
663 /*
664 * We don't really want Joe User generating more
665 * than 64Hz of interrupts on a multi-user machine.
666 */
667 if (!kernel && (arg > rtc_max_user_freq) &&
668 !capable(CAP_SYS_RESOURCE))
669 return -EACCES;
670
671 while (arg > (1<<tmp))
672 tmp++;
673
674 /*
675 * Check that the input was really a power of 2.
676 */
677 if (arg != (1<<tmp))
678 return -EINVAL;
679
680 rtc_freq = arg;
681
682 spin_lock_irqsave(&rtc_lock, flags);
683 if (hpet_set_periodic_freq(arg)) {
684 spin_unlock_irqrestore(&rtc_lock, flags);
685 return 0;
686 }
687
688 val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
689 val |= (16 - tmp);
690 CMOS_WRITE(val, RTC_FREQ_SELECT);
691 spin_unlock_irqrestore(&rtc_lock, flags);
692 return 0;
693 }
694 #endif
695 case RTC_EPOCH_READ: /* Read the epoch. */
696 {
697 return put_user(epoch, (unsigned long __user *)arg);
698 }
699 case RTC_EPOCH_SET: /* Set the epoch. */
700 {
701 /*
702 * There were no RTC clocks before 1900.
703 */
704 if (arg < 1900)
705 return -EINVAL;
706
707 if (!capable(CAP_SYS_TIME))
708 return -EACCES;
709
710 epoch = arg;
711 return 0;
712 }
713 default:
714 return -ENOTTY;
715 }
716 return copy_to_user((void __user *)arg,
717 &wtime, sizeof wtime) ? -EFAULT : 0;
718 }
719
rtc_ioctl(struct file * file,unsigned int cmd,unsigned long arg)720 static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
721 {
722 long ret;
723 ret = rtc_do_ioctl(cmd, arg, 0);
724 return ret;
725 }
726
727 /*
728 * We enforce only one user at a time here with the open/close.
729 * Also clear the previous interrupt data on an open, and clean
730 * up things on a close.
731 */
rtc_open(struct inode * inode,struct file * file)732 static int rtc_open(struct inode *inode, struct file *file)
733 {
734 spin_lock_irq(&rtc_lock);
735
736 if (rtc_status & RTC_IS_OPEN)
737 goto out_busy;
738
739 rtc_status |= RTC_IS_OPEN;
740
741 rtc_irq_data = 0;
742 spin_unlock_irq(&rtc_lock);
743 return 0;
744
745 out_busy:
746 spin_unlock_irq(&rtc_lock);
747 return -EBUSY;
748 }
749
rtc_fasync(int fd,struct file * filp,int on)750 static int rtc_fasync(int fd, struct file *filp, int on)
751 {
752 return fasync_helper(fd, filp, on, &rtc_async_queue);
753 }
754
rtc_release(struct inode * inode,struct file * file)755 static int rtc_release(struct inode *inode, struct file *file)
756 {
757 #ifdef RTC_IRQ
758 unsigned char tmp;
759
760 if (rtc_has_irq == 0)
761 goto no_irq;
762
763 /*
764 * Turn off all interrupts once the device is no longer
765 * in use, and clear the data.
766 */
767
768 spin_lock_irq(&rtc_lock);
769 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
770 tmp = CMOS_READ(RTC_CONTROL);
771 tmp &= ~RTC_PIE;
772 tmp &= ~RTC_AIE;
773 tmp &= ~RTC_UIE;
774 CMOS_WRITE(tmp, RTC_CONTROL);
775 CMOS_READ(RTC_INTR_FLAGS);
776 }
777 if (rtc_status & RTC_TIMER_ON) {
778 rtc_status &= ~RTC_TIMER_ON;
779 del_timer(&rtc_irq_timer);
780 }
781 spin_unlock_irq(&rtc_lock);
782
783 no_irq:
784 #endif
785
786 spin_lock_irq(&rtc_lock);
787 rtc_irq_data = 0;
788 rtc_status &= ~RTC_IS_OPEN;
789 spin_unlock_irq(&rtc_lock);
790
791 return 0;
792 }
793
794 #ifdef RTC_IRQ
rtc_poll(struct file * file,poll_table * wait)795 static unsigned int rtc_poll(struct file *file, poll_table *wait)
796 {
797 unsigned long l;
798
799 if (rtc_has_irq == 0)
800 return 0;
801
802 poll_wait(file, &rtc_wait, wait);
803
804 spin_lock_irq(&rtc_lock);
805 l = rtc_irq_data;
806 spin_unlock_irq(&rtc_lock);
807
808 if (l != 0)
809 return POLLIN | POLLRDNORM;
810 return 0;
811 }
812 #endif
813
rtc_register(rtc_task_t * task)814 int rtc_register(rtc_task_t *task)
815 {
816 #ifndef RTC_IRQ
817 return -EIO;
818 #else
819 if (task == NULL || task->func == NULL)
820 return -EINVAL;
821 spin_lock_irq(&rtc_lock);
822 if (rtc_status & RTC_IS_OPEN) {
823 spin_unlock_irq(&rtc_lock);
824 return -EBUSY;
825 }
826 spin_lock(&rtc_task_lock);
827 if (rtc_callback) {
828 spin_unlock(&rtc_task_lock);
829 spin_unlock_irq(&rtc_lock);
830 return -EBUSY;
831 }
832 rtc_status |= RTC_IS_OPEN;
833 rtc_callback = task;
834 spin_unlock(&rtc_task_lock);
835 spin_unlock_irq(&rtc_lock);
836 return 0;
837 #endif
838 }
839 EXPORT_SYMBOL(rtc_register);
840
rtc_unregister(rtc_task_t * task)841 int rtc_unregister(rtc_task_t *task)
842 {
843 #ifndef RTC_IRQ
844 return -EIO;
845 #else
846 unsigned char tmp;
847
848 spin_lock_irq(&rtc_lock);
849 spin_lock(&rtc_task_lock);
850 if (rtc_callback != task) {
851 spin_unlock(&rtc_task_lock);
852 spin_unlock_irq(&rtc_lock);
853 return -ENXIO;
854 }
855 rtc_callback = NULL;
856
857 /* disable controls */
858 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
859 tmp = CMOS_READ(RTC_CONTROL);
860 tmp &= ~RTC_PIE;
861 tmp &= ~RTC_AIE;
862 tmp &= ~RTC_UIE;
863 CMOS_WRITE(tmp, RTC_CONTROL);
864 CMOS_READ(RTC_INTR_FLAGS);
865 }
866 if (rtc_status & RTC_TIMER_ON) {
867 rtc_status &= ~RTC_TIMER_ON;
868 del_timer(&rtc_irq_timer);
869 }
870 rtc_status &= ~RTC_IS_OPEN;
871 spin_unlock(&rtc_task_lock);
872 spin_unlock_irq(&rtc_lock);
873 return 0;
874 #endif
875 }
876 EXPORT_SYMBOL(rtc_unregister);
877
rtc_control(rtc_task_t * task,unsigned int cmd,unsigned long arg)878 int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
879 {
880 #ifndef RTC_IRQ
881 return -EIO;
882 #else
883 unsigned long flags;
884 if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET)
885 return -EINVAL;
886 spin_lock_irqsave(&rtc_task_lock, flags);
887 if (rtc_callback != task) {
888 spin_unlock_irqrestore(&rtc_task_lock, flags);
889 return -ENXIO;
890 }
891 spin_unlock_irqrestore(&rtc_task_lock, flags);
892 return rtc_do_ioctl(cmd, arg, 1);
893 #endif
894 }
895 EXPORT_SYMBOL(rtc_control);
896
897 /*
898 * The various file operations we support.
899 */
900
901 static const struct file_operations rtc_fops = {
902 .owner = THIS_MODULE,
903 .llseek = no_llseek,
904 .read = rtc_read,
905 #ifdef RTC_IRQ
906 .poll = rtc_poll,
907 #endif
908 .unlocked_ioctl = rtc_ioctl,
909 .open = rtc_open,
910 .release = rtc_release,
911 .fasync = rtc_fasync,
912 };
913
914 static struct miscdevice rtc_dev = {
915 .minor = RTC_MINOR,
916 .name = "rtc",
917 .fops = &rtc_fops,
918 };
919
920 #ifdef CONFIG_PROC_FS
921 static const struct file_operations rtc_proc_fops = {
922 .owner = THIS_MODULE,
923 .open = rtc_proc_open,
924 .read = seq_read,
925 .llseek = seq_lseek,
926 .release = single_release,
927 };
928 #endif
929
930 static resource_size_t rtc_size;
931
rtc_request_region(resource_size_t size)932 static struct resource * __init rtc_request_region(resource_size_t size)
933 {
934 struct resource *r;
935
936 if (RTC_IOMAPPED)
937 r = request_region(RTC_PORT(0), size, "rtc");
938 else
939 r = request_mem_region(RTC_PORT(0), size, "rtc");
940
941 if (r)
942 rtc_size = size;
943
944 return r;
945 }
946
rtc_release_region(void)947 static void rtc_release_region(void)
948 {
949 if (RTC_IOMAPPED)
950 release_region(RTC_PORT(0), rtc_size);
951 else
952 release_mem_region(RTC_PORT(0), rtc_size);
953 }
954
rtc_init(void)955 static int __init rtc_init(void)
956 {
957 #ifdef CONFIG_PROC_FS
958 struct proc_dir_entry *ent;
959 #endif
960 #if defined(__alpha__) || defined(__mips__)
961 unsigned int year, ctrl;
962 char *guess = NULL;
963 #endif
964 #ifdef CONFIG_SPARC32
965 struct device_node *ebus_dp;
966 struct of_device *op;
967 #else
968 void *r;
969 #ifdef RTC_IRQ
970 irq_handler_t rtc_int_handler_ptr;
971 #endif
972 #endif
973
974 #ifdef CONFIG_SPARC32
975 for_each_node_by_name(ebus_dp, "ebus") {
976 struct device_node *dp;
977 for (dp = ebus_dp; dp; dp = dp->sibling) {
978 if (!strcmp(dp->name, "rtc")) {
979 op = of_find_device_by_node(dp);
980 if (op) {
981 rtc_port = op->resource[0].start;
982 rtc_irq = op->irqs[0];
983 goto found;
984 }
985 }
986 }
987 }
988 rtc_has_irq = 0;
989 printk(KERN_ERR "rtc_init: no PC rtc found\n");
990 return -EIO;
991
992 found:
993 if (!rtc_irq) {
994 rtc_has_irq = 0;
995 goto no_irq;
996 }
997
998 /*
999 * XXX Interrupt pin #7 in Espresso is shared between RTC and
1000 * PCI Slot 2 INTA# (and some INTx# in Slot 1).
1001 */
1002 if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc",
1003 (void *)&rtc_port)) {
1004 rtc_has_irq = 0;
1005 printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq);
1006 return -EIO;
1007 }
1008 no_irq:
1009 #else
1010 r = rtc_request_region(RTC_IO_EXTENT);
1011
1012 /*
1013 * If we've already requested a smaller range (for example, because
1014 * PNPBIOS or ACPI told us how the device is configured), the request
1015 * above might fail because it's too big.
1016 *
1017 * If so, request just the range we actually use.
1018 */
1019 if (!r)
1020 r = rtc_request_region(RTC_IO_EXTENT_USED);
1021 if (!r) {
1022 #ifdef RTC_IRQ
1023 rtc_has_irq = 0;
1024 #endif
1025 printk(KERN_ERR "rtc: I/O resource %lx is not free.\n",
1026 (long)(RTC_PORT(0)));
1027 return -EIO;
1028 }
1029
1030 #ifdef RTC_IRQ
1031 if (is_hpet_enabled()) {
1032 int err;
1033
1034 rtc_int_handler_ptr = hpet_rtc_interrupt;
1035 err = hpet_register_irq_handler(rtc_interrupt);
1036 if (err != 0) {
1037 printk(KERN_WARNING "hpet_register_irq_handler failed "
1038 "in rtc_init().");
1039 return err;
1040 }
1041 } else {
1042 rtc_int_handler_ptr = rtc_interrupt;
1043 }
1044
1045 if (request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED,
1046 "rtc", NULL)) {
1047 /* Yeah right, seeing as irq 8 doesn't even hit the bus. */
1048 rtc_has_irq = 0;
1049 printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
1050 rtc_release_region();
1051
1052 return -EIO;
1053 }
1054 hpet_rtc_timer_init();
1055
1056 #endif
1057
1058 #endif /* CONFIG_SPARC32 vs. others */
1059
1060 if (misc_register(&rtc_dev)) {
1061 #ifdef RTC_IRQ
1062 free_irq(RTC_IRQ, NULL);
1063 hpet_unregister_irq_handler(rtc_interrupt);
1064 rtc_has_irq = 0;
1065 #endif
1066 rtc_release_region();
1067 return -ENODEV;
1068 }
1069
1070 #ifdef CONFIG_PROC_FS
1071 ent = proc_create("driver/rtc", 0, NULL, &rtc_proc_fops);
1072 if (!ent)
1073 printk(KERN_WARNING "rtc: Failed to register with procfs.\n");
1074 #endif
1075
1076 #if defined(__alpha__) || defined(__mips__)
1077 rtc_freq = HZ;
1078
1079 /* Each operating system on an Alpha uses its own epoch.
1080 Let's try to guess which one we are using now. */
1081
1082 if (rtc_is_updating() != 0)
1083 msleep(20);
1084
1085 spin_lock_irq(&rtc_lock);
1086 year = CMOS_READ(RTC_YEAR);
1087 ctrl = CMOS_READ(RTC_CONTROL);
1088 spin_unlock_irq(&rtc_lock);
1089
1090 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1091 year = bcd2bin(year); /* This should never happen... */
1092
1093 if (year < 20) {
1094 epoch = 2000;
1095 guess = "SRM (post-2000)";
1096 } else if (year >= 20 && year < 48) {
1097 epoch = 1980;
1098 guess = "ARC console";
1099 } else if (year >= 48 && year < 72) {
1100 epoch = 1952;
1101 guess = "Digital UNIX";
1102 #if defined(__mips__)
1103 } else if (year >= 72 && year < 74) {
1104 epoch = 2000;
1105 guess = "Digital DECstation";
1106 #else
1107 } else if (year >= 70) {
1108 epoch = 1900;
1109 guess = "Standard PC (1900)";
1110 #endif
1111 }
1112 if (guess)
1113 printk(KERN_INFO "rtc: %s epoch (%lu) detected\n",
1114 guess, epoch);
1115 #endif
1116 #ifdef RTC_IRQ
1117 if (rtc_has_irq == 0)
1118 goto no_irq2;
1119
1120 spin_lock_irq(&rtc_lock);
1121 rtc_freq = 1024;
1122 if (!hpet_set_periodic_freq(rtc_freq)) {
1123 /*
1124 * Initialize periodic frequency to CMOS reset default,
1125 * which is 1024Hz
1126 */
1127 CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06),
1128 RTC_FREQ_SELECT);
1129 }
1130 spin_unlock_irq(&rtc_lock);
1131 no_irq2:
1132 #endif
1133
1134 (void) init_sysctl();
1135
1136 printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
1137
1138 return 0;
1139 }
1140
rtc_exit(void)1141 static void __exit rtc_exit(void)
1142 {
1143 cleanup_sysctl();
1144 remove_proc_entry("driver/rtc", NULL);
1145 misc_deregister(&rtc_dev);
1146
1147 #ifdef CONFIG_SPARC32
1148 if (rtc_has_irq)
1149 free_irq(rtc_irq, &rtc_port);
1150 #else
1151 rtc_release_region();
1152 #ifdef RTC_IRQ
1153 if (rtc_has_irq) {
1154 free_irq(RTC_IRQ, NULL);
1155 hpet_unregister_irq_handler(hpet_rtc_interrupt);
1156 }
1157 #endif
1158 #endif /* CONFIG_SPARC32 */
1159 }
1160
1161 module_init(rtc_init);
1162 module_exit(rtc_exit);
1163
1164 #ifdef RTC_IRQ
1165 /*
1166 * At IRQ rates >= 4096Hz, an interrupt may get lost altogether.
1167 * (usually during an IDE disk interrupt, with IRQ unmasking off)
1168 * Since the interrupt handler doesn't get called, the IRQ status
1169 * byte doesn't get read, and the RTC stops generating interrupts.
1170 * A timer is set, and will call this function if/when that happens.
1171 * To get it out of this stalled state, we just read the status.
1172 * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost.
1173 * (You *really* shouldn't be trying to use a non-realtime system
1174 * for something that requires a steady > 1KHz signal anyways.)
1175 */
1176
rtc_dropped_irq(unsigned long data)1177 static void rtc_dropped_irq(unsigned long data)
1178 {
1179 unsigned long freq;
1180
1181 spin_lock_irq(&rtc_lock);
1182
1183 if (hpet_rtc_dropped_irq()) {
1184 spin_unlock_irq(&rtc_lock);
1185 return;
1186 }
1187
1188 /* Just in case someone disabled the timer from behind our back... */
1189 if (rtc_status & RTC_TIMER_ON)
1190 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
1191
1192 rtc_irq_data += ((rtc_freq/HZ)<<8);
1193 rtc_irq_data &= ~0xff;
1194 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */
1195
1196 freq = rtc_freq;
1197
1198 spin_unlock_irq(&rtc_lock);
1199
1200 if (printk_ratelimit()) {
1201 printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n",
1202 freq);
1203 }
1204
1205 /* Now we have new data */
1206 wake_up_interruptible(&rtc_wait);
1207
1208 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
1209 }
1210 #endif
1211
1212 #ifdef CONFIG_PROC_FS
1213 /*
1214 * Info exported via "/proc/driver/rtc".
1215 */
1216
rtc_proc_show(struct seq_file * seq,void * v)1217 static int rtc_proc_show(struct seq_file *seq, void *v)
1218 {
1219 #define YN(bit) ((ctrl & bit) ? "yes" : "no")
1220 #define NY(bit) ((ctrl & bit) ? "no" : "yes")
1221 struct rtc_time tm;
1222 unsigned char batt, ctrl;
1223 unsigned long freq;
1224
1225 spin_lock_irq(&rtc_lock);
1226 batt = CMOS_READ(RTC_VALID) & RTC_VRT;
1227 ctrl = CMOS_READ(RTC_CONTROL);
1228 freq = rtc_freq;
1229 spin_unlock_irq(&rtc_lock);
1230
1231
1232 rtc_get_rtc_time(&tm);
1233
1234 /*
1235 * There is no way to tell if the luser has the RTC set for local
1236 * time or for Universal Standard Time (GMT). Probably local though.
1237 */
1238 seq_printf(seq,
1239 "rtc_time\t: %02d:%02d:%02d\n"
1240 "rtc_date\t: %04d-%02d-%02d\n"
1241 "rtc_epoch\t: %04lu\n",
1242 tm.tm_hour, tm.tm_min, tm.tm_sec,
1243 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
1244
1245 get_rtc_alm_time(&tm);
1246
1247 /*
1248 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
1249 * match any value for that particular field. Values that are
1250 * greater than a valid time, but less than 0xc0 shouldn't appear.
1251 */
1252 seq_puts(seq, "alarm\t\t: ");
1253 if (tm.tm_hour <= 24)
1254 seq_printf(seq, "%02d:", tm.tm_hour);
1255 else
1256 seq_puts(seq, "**:");
1257
1258 if (tm.tm_min <= 59)
1259 seq_printf(seq, "%02d:", tm.tm_min);
1260 else
1261 seq_puts(seq, "**:");
1262
1263 if (tm.tm_sec <= 59)
1264 seq_printf(seq, "%02d\n", tm.tm_sec);
1265 else
1266 seq_puts(seq, "**\n");
1267
1268 seq_printf(seq,
1269 "DST_enable\t: %s\n"
1270 "BCD\t\t: %s\n"
1271 "24hr\t\t: %s\n"
1272 "square_wave\t: %s\n"
1273 "alarm_IRQ\t: %s\n"
1274 "update_IRQ\t: %s\n"
1275 "periodic_IRQ\t: %s\n"
1276 "periodic_freq\t: %ld\n"
1277 "batt_status\t: %s\n",
1278 YN(RTC_DST_EN),
1279 NY(RTC_DM_BINARY),
1280 YN(RTC_24H),
1281 YN(RTC_SQWE),
1282 YN(RTC_AIE),
1283 YN(RTC_UIE),
1284 YN(RTC_PIE),
1285 freq,
1286 batt ? "okay" : "dead");
1287
1288 return 0;
1289 #undef YN
1290 #undef NY
1291 }
1292
rtc_proc_open(struct inode * inode,struct file * file)1293 static int rtc_proc_open(struct inode *inode, struct file *file)
1294 {
1295 return single_open(file, rtc_proc_show, NULL);
1296 }
1297 #endif
1298
rtc_get_rtc_time(struct rtc_time * rtc_tm)1299 static void rtc_get_rtc_time(struct rtc_time *rtc_tm)
1300 {
1301 unsigned long uip_watchdog = jiffies, flags;
1302 unsigned char ctrl;
1303 #ifdef CONFIG_MACH_DECSTATION
1304 unsigned int real_year;
1305 #endif
1306
1307 /*
1308 * read RTC once any update in progress is done. The update
1309 * can take just over 2ms. We wait 20ms. There is no need to
1310 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
1311 * If you need to know *exactly* when a second has started, enable
1312 * periodic update complete interrupts, (via ioctl) and then
1313 * immediately read /dev/rtc which will block until you get the IRQ.
1314 * Once the read clears, read the RTC time (again via ioctl). Easy.
1315 */
1316
1317 while (rtc_is_updating() != 0 &&
1318 time_before(jiffies, uip_watchdog + 2*HZ/100))
1319 cpu_relax();
1320
1321 /*
1322 * Only the values that we read from the RTC are set. We leave
1323 * tm_wday, tm_yday and tm_isdst untouched. Note that while the
1324 * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is
1325 * only updated by the RTC when initially set to a non-zero value.
1326 */
1327 spin_lock_irqsave(&rtc_lock, flags);
1328 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
1329 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
1330 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
1331 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
1332 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
1333 rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
1334 /* Only set from 2.6.16 onwards */
1335 rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK);
1336
1337 #ifdef CONFIG_MACH_DECSTATION
1338 real_year = CMOS_READ(RTC_DEC_YEAR);
1339 #endif
1340 ctrl = CMOS_READ(RTC_CONTROL);
1341 spin_unlock_irqrestore(&rtc_lock, flags);
1342
1343 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
1344 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
1345 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
1346 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
1347 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
1348 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
1349 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
1350 rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
1351 }
1352
1353 #ifdef CONFIG_MACH_DECSTATION
1354 rtc_tm->tm_year += real_year - 72;
1355 #endif
1356
1357 /*
1358 * Account for differences between how the RTC uses the values
1359 * and how they are defined in a struct rtc_time;
1360 */
1361 rtc_tm->tm_year += epoch - 1900;
1362 if (rtc_tm->tm_year <= 69)
1363 rtc_tm->tm_year += 100;
1364
1365 rtc_tm->tm_mon--;
1366 }
1367
get_rtc_alm_time(struct rtc_time * alm_tm)1368 static void get_rtc_alm_time(struct rtc_time *alm_tm)
1369 {
1370 unsigned char ctrl;
1371
1372 /*
1373 * Only the values that we read from the RTC are set. That
1374 * means only tm_hour, tm_min, and tm_sec.
1375 */
1376 spin_lock_irq(&rtc_lock);
1377 alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
1378 alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM);
1379 alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM);
1380 ctrl = CMOS_READ(RTC_CONTROL);
1381 spin_unlock_irq(&rtc_lock);
1382
1383 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
1384 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
1385 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
1386 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
1387 }
1388 }
1389
1390 #ifdef RTC_IRQ
1391 /*
1392 * Used to disable/enable interrupts for any one of UIE, AIE, PIE.
1393 * Rumour has it that if you frob the interrupt enable/disable
1394 * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to
1395 * ensure you actually start getting interrupts. Probably for
1396 * compatibility with older/broken chipset RTC implementations.
1397 * We also clear out any old irq data after an ioctl() that
1398 * meddles with the interrupt enable/disable bits.
1399 */
1400
mask_rtc_irq_bit_locked(unsigned char bit)1401 static void mask_rtc_irq_bit_locked(unsigned char bit)
1402 {
1403 unsigned char val;
1404
1405 if (hpet_mask_rtc_irq_bit(bit))
1406 return;
1407 val = CMOS_READ(RTC_CONTROL);
1408 val &= ~bit;
1409 CMOS_WRITE(val, RTC_CONTROL);
1410 CMOS_READ(RTC_INTR_FLAGS);
1411
1412 rtc_irq_data = 0;
1413 }
1414
set_rtc_irq_bit_locked(unsigned char bit)1415 static void set_rtc_irq_bit_locked(unsigned char bit)
1416 {
1417 unsigned char val;
1418
1419 if (hpet_set_rtc_irq_bit(bit))
1420 return;
1421 val = CMOS_READ(RTC_CONTROL);
1422 val |= bit;
1423 CMOS_WRITE(val, RTC_CONTROL);
1424 CMOS_READ(RTC_INTR_FLAGS);
1425
1426 rtc_irq_data = 0;
1427 }
1428 #endif
1429
1430 MODULE_AUTHOR("Paul Gortmaker");
1431 MODULE_LICENSE("GPL");
1432 MODULE_ALIAS_MISCDEV(RTC_MINOR);
1433