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[MOXA]: Fix this driver properly.
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / char / rtc.c
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1da177e4
LT		 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 *
50 */
51
52#define RTC_VERSION "1.12"
53
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
64#include <linux/config.h>
65#include <linux/interrupt.h>
66#include <linux/module.h>
67#include <linux/kernel.h>
68#include <linux/types.h>
69#include <linux/miscdevice.h>
70#include <linux/ioport.h>
71#include <linux/fcntl.h>
72#include <linux/mc146818rtc.h>
73#include <linux/init.h>
74#include <linux/poll.h>
75#include <linux/proc_fs.h>
76#include <linux/seq_file.h>
77#include <linux/spinlock.h>
78#include <linux/sysctl.h>
79#include <linux/wait.h>
80#include <linux/bcd.h>
47f176fd 81#include <linux/delay.h>
1da177e4
LT		 82
83#include <asm/current.h>
84#include <asm/uaccess.h>
85#include <asm/system.h>
86
87#if defined(__i386__)
88#include <asm/hpet.h>
89#endif
90
91#ifdef __sparc__
92#include <linux/pci.h>
93#include <asm/ebus.h>
94#ifdef __sparc_v9__
95#include <asm/isa.h>
96#endif
97
98static unsigned long rtc_port;
99static int rtc_irq = PCI_IRQ_NONE;
100#endif
101
102#ifdef CONFIG_HPET_RTC_IRQ
103#undef RTC_IRQ
104#endif
105
106#ifdef RTC_IRQ
107static int rtc_has_irq = 1;
108#endif
109
110#ifndef CONFIG_HPET_EMULATE_RTC
111#define is_hpet_enabled() 0
112#define hpet_set_alarm_time(hrs, min, sec) 0
113#define hpet_set_periodic_freq(arg) 0
114#define hpet_mask_rtc_irq_bit(arg) 0
115#define hpet_set_rtc_irq_bit(arg) 0
116#define hpet_rtc_timer_init() do { } while (0)
117#define hpet_rtc_dropped_irq() 0
118static inline irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs) {return 0;}
119#else
120extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs);
121#endif
122
123/*
124 * We sponge a minor off of the misc major. No need slurping
125 * up another valuable major dev number for this. If you add
126 * an ioctl, make sure you don't conflict with SPARC's RTC
127 * ioctls.
128 */
129
130static struct fasync_struct *rtc_async_queue;
131
132static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
133
134#ifdef RTC_IRQ
135static struct timer_list rtc_irq_timer;
136#endif
137
138static ssize_t rtc_read(struct file *file, char __user *buf,
139 size_t count, loff_t *ppos);
140
141static int rtc_ioctl(struct inode *inode, struct file *file,
142 unsigned int cmd, unsigned long arg);
143
144#ifdef RTC_IRQ
145static unsigned int rtc_poll(struct file *file, poll_table *wait);
146#endif
147
148static void get_rtc_alm_time (struct rtc_time *alm_tm);
149#ifdef RTC_IRQ
150static void rtc_dropped_irq(unsigned long data);
151
152static void set_rtc_irq_bit(unsigned char bit);
153static void mask_rtc_irq_bit(unsigned char bit);
154#endif
155
156static int rtc_proc_open(struct inode *inode, struct file *file);
157
158/*
159 * Bits in rtc_status. (6 bits of room for future expansion)
160 */
161
162#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
163#define RTC_TIMER_ON 0x02 /* missed irq timer active */
164
165/*
166 * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is
167 * protected by the big kernel lock. However, ioctl can still disable the timer
168 * in rtc_status and then with del_timer after the interrupt has read
169 * rtc_status but before mod_timer is called, which would then reenable the
170 * timer (but you would need to have an awful timing before you'd trip on it)
171 */
172static unsigned long rtc_status = 0; /* bitmapped status byte. */
173static unsigned long rtc_freq = 0; /* Current periodic IRQ rate */
174static unsigned long rtc_irq_data = 0; /* our output to the world */
175static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */
176
177#ifdef RTC_IRQ
178/*
179 * rtc_task_lock nests inside rtc_lock.
180 */
181static DEFINE_SPINLOCK(rtc_task_lock);
182static rtc_task_t *rtc_callback = NULL;
183#endif
184
185/*
186 * If this driver ever becomes modularised, it will be really nice
187 * to make the epoch retain its value across module reload...
188 */
189
190static unsigned long epoch = 1900; /* year corresponding to 0x00 */
191
192static const unsigned char days_in_mo[] =
193{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
194
195/*
196 * Returns true if a clock update is in progress
197 */
198static inline unsigned char rtc_is_updating(void)
199{
200 unsigned char uip;
201
202 spin_lock_irq(&rtc_lock);
203 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
204 spin_unlock_irq(&rtc_lock);
205 return uip;
206}
207
208#ifdef RTC_IRQ
209/*
210 * A very tiny interrupt handler. It runs with SA_INTERRUPT set,
211 * but there is possibility of conflicting with the set_rtc_mmss()
212 * call (the rtc irq and the timer irq can easily run at the same
213 * time in two different CPUs). So we need to serialize
214 * accesses to the chip with the rtc_lock spinlock that each
215 * architecture should implement in the timer code.
216 * (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.)
217 */
218
219irqreturn_t rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
220{
221 /*
222 * Can be an alarm interrupt, update complete interrupt,
223 * or a periodic interrupt. We store the status in the
224 * low byte and the number of interrupts received since
225 * the last read in the remainder of rtc_irq_data.
226 */
227
228 spin_lock (&rtc_lock);
229 rtc_irq_data += 0x100;
230 rtc_irq_data &= ~0xff;
231 if (is_hpet_enabled()) {
232 /*
233 * In this case it is HPET RTC interrupt handler
234 * calling us, with the interrupt information
235 * passed as arg1, instead of irq.
236 */
237 rtc_irq_data |= (unsigned long)irq & 0xF0;
238 } else {
239 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0);
240 }
241
242 if (rtc_status & RTC_TIMER_ON)
243 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
244
245 spin_unlock (&rtc_lock);
246
247 /* Now do the rest of the actions */
248 spin_lock(&rtc_task_lock);
249 if (rtc_callback)
250 rtc_callback->func(rtc_callback->private_data);
251 spin_unlock(&rtc_task_lock);
252 wake_up_interruptible(&rtc_wait);
253
254 kill_fasync (&rtc_async_queue, SIGIO, POLL_IN);
255
256 return IRQ_HANDLED;
257}
258#endif
259
260/*
261 * sysctl-tuning infrastructure.
262 */
263static ctl_table rtc_table[] = {
264 {
265 .ctl_name = 1,
266 .procname = "max-user-freq",
267 .data = &rtc_max_user_freq,
268 .maxlen = sizeof(int),
269 .mode = 0644,
270 .proc_handler = &proc_dointvec,
271 },
272 { .ctl_name = 0 }
273};
274
275static ctl_table rtc_root[] = {
276 {
277 .ctl_name = 1,
278 .procname = "rtc",
279 .maxlen = 0,
280 .mode = 0555,
281 .child = rtc_table,
282 },
283 { .ctl_name = 0 }
284};
285
286static ctl_table dev_root[] = {
287 {
288 .ctl_name = CTL_DEV,
289 .procname = "dev",
290 .maxlen = 0,
291 .mode = 0555,
292 .child = rtc_root,
293 },
294 { .ctl_name = 0 }
295};
296
297static struct ctl_table_header *sysctl_header;
298
299static int __init init_sysctl(void)
300{
301 sysctl_header = register_sysctl_table(dev_root, 0);
302 return 0;
303}
304
305static void __exit cleanup_sysctl(void)
306{
307 unregister_sysctl_table(sysctl_header);
308}
309
310/*
311 * Now all the various file operations that we export.
312 */
313
314static ssize_t rtc_read(struct file *file, char __user *buf,
315 size_t count, loff_t *ppos)
316{
317#ifndef RTC_IRQ
318 return -EIO;
319#else
320 DECLARE_WAITQUEUE(wait, current);
321 unsigned long data;
322 ssize_t retval;
323
324 if (rtc_has_irq == 0)
325 return -EIO;
326
327 if (count < sizeof(unsigned))
328 return -EINVAL;
329
330 add_wait_queue(&rtc_wait, &wait);
331
332 do {
333 /* First make it right. Then make it fast. Putting this whole
334 * block within the parentheses of a while would be too
335 * confusing. And no, xchg() is not the answer. */
336
337 __set_current_state(TASK_INTERRUPTIBLE);
338
339 spin_lock_irq (&rtc_lock);
340 data = rtc_irq_data;
341 rtc_irq_data = 0;
342 spin_unlock_irq (&rtc_lock);
343
344 if (data != 0)
345 break;
346
347 if (file->f_flags & O_NONBLOCK) {
348 retval = -EAGAIN;
349 goto out;
350 }
351 if (signal_pending(current)) {
352 retval = -ERESTARTSYS;
353 goto out;
354 }
355 schedule();
356 } while (1);
357
358 if (count < sizeof(unsigned long))
359 retval = put_user(data, (unsigned int __user *)buf) ?: sizeof(int);
360 else
361 retval = put_user(data, (unsigned long __user *)buf) ?: sizeof(long);
362 out:
363 current->state = TASK_RUNNING;
364 remove_wait_queue(&rtc_wait, &wait);
365
366 return retval;
367#endif
368}
369
370static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
371{
372 struct rtc_time wtime;
373
374#ifdef RTC_IRQ
375 if (rtc_has_irq == 0) {
376 switch (cmd) {
377 case RTC_AIE_OFF:
378 case RTC_AIE_ON:
379 case RTC_PIE_OFF:
380 case RTC_PIE_ON:
381 case RTC_UIE_OFF:
382 case RTC_UIE_ON:
383 case RTC_IRQP_READ:
384 case RTC_IRQP_SET:
385 return -EINVAL;
386 };
387 }
388#endif
389
390 switch (cmd) {
391#ifdef RTC_IRQ
392 case RTC_AIE_OFF: /* Mask alarm int. enab. bit */
393 {
394 mask_rtc_irq_bit(RTC_AIE);
395 return 0;
396 }
397 case RTC_AIE_ON: /* Allow alarm interrupts. */
398 {
399 set_rtc_irq_bit(RTC_AIE);
400 return 0;
401 }
402 case RTC_PIE_OFF: /* Mask periodic int. enab. bit */
403 {
404 mask_rtc_irq_bit(RTC_PIE);
405 if (rtc_status & RTC_TIMER_ON) {
406 spin_lock_irq (&rtc_lock);
407 rtc_status &= ~RTC_TIMER_ON;
408 del_timer(&rtc_irq_timer);
409 spin_unlock_irq (&rtc_lock);
410 }
411 return 0;
412 }
413 case RTC_PIE_ON: /* Allow periodic ints */
414 {
415
416 /*
417 * We don't really want Joe User enabling more
418 * than 64Hz of interrupts on a multi-user machine.
419 */
420 if (!kernel && (rtc_freq > rtc_max_user_freq) &&
421 (!capable(CAP_SYS_RESOURCE)))
422 return -EACCES;
423
424 if (!(rtc_status & RTC_TIMER_ON)) {
425 spin_lock_irq (&rtc_lock);
426 rtc_irq_timer.expires = jiffies + HZ/rtc_freq + 2*HZ/100;
427 add_timer(&rtc_irq_timer);
428 rtc_status |= RTC_TIMER_ON;
429 spin_unlock_irq (&rtc_lock);
430 }
431 set_rtc_irq_bit(RTC_PIE);
432 return 0;
433 }
434 case RTC_UIE_OFF: /* Mask ints from RTC updates. */
435 {
436 mask_rtc_irq_bit(RTC_UIE);
437 return 0;
438 }
439 case RTC_UIE_ON: /* Allow ints for RTC updates. */
440 {
441 set_rtc_irq_bit(RTC_UIE);
442 return 0;
443 }
444#endif
445 case RTC_ALM_READ: /* Read the present alarm time */
446 {
447 /*
448 * This returns a struct rtc_time. Reading >= 0xc0
449 * means "don't care" or "match all". Only the tm_hour,
450 * tm_min, and tm_sec values are filled in.
451 */
452 memset(&wtime, 0, sizeof(struct rtc_time));
453 get_rtc_alm_time(&wtime);
454 break;
455 }
456 case RTC_ALM_SET: /* Store a time into the alarm */
457 {
458 /*
459 * This expects a struct rtc_time. Writing 0xff means
460 * "don't care" or "match all". Only the tm_hour,
461 * tm_min and tm_sec are used.
462 */
463 unsigned char hrs, min, sec;
464 struct rtc_time alm_tm;
465
466 if (copy_from_user(&alm_tm, (struct rtc_time __user *)arg,
467 sizeof(struct rtc_time)))
468 return -EFAULT;
469
470 hrs = alm_tm.tm_hour;
471 min = alm_tm.tm_min;
472 sec = alm_tm.tm_sec;
473
474 spin_lock_irq(&rtc_lock);
475 if (hpet_set_alarm_time(hrs, min, sec)) {
476 /*
477 * Fallthru and set alarm time in CMOS too,
478 * so that we will get proper value in RTC_ALM_READ
479 */
480 }
481 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) ||
482 RTC_ALWAYS_BCD)
483 {
484 if (sec < 60) BIN_TO_BCD(sec);
485 else sec = 0xff;
486
487 if (min < 60) BIN_TO_BCD(min);
488 else min = 0xff;
489
490 if (hrs < 24) BIN_TO_BCD(hrs);
491 else hrs = 0xff;
492 }
493 CMOS_WRITE(hrs, RTC_HOURS_ALARM);
494 CMOS_WRITE(min, RTC_MINUTES_ALARM);
495 CMOS_WRITE(sec, RTC_SECONDS_ALARM);
496 spin_unlock_irq(&rtc_lock);
497
498 return 0;
499 }
500 case RTC_RD_TIME: /* Read the time/date from RTC */
501 {
502 memset(&wtime, 0, sizeof(struct rtc_time));
503 rtc_get_rtc_time(&wtime);
504 break;
505 }
506 case RTC_SET_TIME: /* Set the RTC */
507 {
508 struct rtc_time rtc_tm;
509 unsigned char mon, day, hrs, min, sec, leap_yr;
510 unsigned char save_control, save_freq_select;
511 unsigned int yrs;
512#ifdef CONFIG_MACH_DECSTATION
513 unsigned int real_yrs;
514#endif
515
516 if (!capable(CAP_SYS_TIME))
517 return -EACCES;
518
519 if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg,
520 sizeof(struct rtc_time)))
521 return -EFAULT;
522
523 yrs = rtc_tm.tm_year + 1900;
524 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
525 day = rtc_tm.tm_mday;
526 hrs = rtc_tm.tm_hour;
527 min = rtc_tm.tm_min;
528 sec = rtc_tm.tm_sec;
529
530 if (yrs < 1970)
531 return -EINVAL;
532
533 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
534
535 if ((mon > 12) || (day == 0))
536 return -EINVAL;
537
538 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
539 return -EINVAL;
540
541 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
542 return -EINVAL;
543
544 if ((yrs -= epoch) > 255) /* They are unsigned */
545 return -EINVAL;
546
547 spin_lock_irq(&rtc_lock);
548#ifdef CONFIG_MACH_DECSTATION
549 real_yrs = yrs;
550 yrs = 72;
551
552 /*
553 * We want to keep the year set to 73 until March
554 * for non-leap years, so that Feb, 29th is handled
555 * correctly.
556 */
557 if (!leap_yr && mon < 3) {
558 real_yrs--;
559 yrs = 73;
560 }
561#endif
562 /* These limits and adjustments are independent of
563 * whether the chip is in binary mode or not.
564 */
565 if (yrs > 169) {
566 spin_unlock_irq(&rtc_lock);
567 return -EINVAL;
568 }
569 if (yrs >= 100)
570 yrs -= 100;
571
572 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
573 || RTC_ALWAYS_BCD) {
574 BIN_TO_BCD(sec);
575 BIN_TO_BCD(min);
576 BIN_TO_BCD(hrs);
577 BIN_TO_BCD(day);
578 BIN_TO_BCD(mon);
579 BIN_TO_BCD(yrs);
580 }
581
582 save_control = CMOS_READ(RTC_CONTROL);
583 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
584 save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
585 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
586
587#ifdef CONFIG_MACH_DECSTATION
588 CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
589#endif
590 CMOS_WRITE(yrs, RTC_YEAR);
591 CMOS_WRITE(mon, RTC_MONTH);
592 CMOS_WRITE(day, RTC_DAY_OF_MONTH);
593 CMOS_WRITE(hrs, RTC_HOURS);
594 CMOS_WRITE(min, RTC_MINUTES);
595 CMOS_WRITE(sec, RTC_SECONDS);
596
597 CMOS_WRITE(save_control, RTC_CONTROL);
598 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
599
600 spin_unlock_irq(&rtc_lock);
601 return 0;
602 }
603#ifdef RTC_IRQ
604 case RTC_IRQP_READ: /* Read the periodic IRQ rate. */
605 {
606 return put_user(rtc_freq, (unsigned long __user *)arg);
607 }
608 case RTC_IRQP_SET: /* Set periodic IRQ rate. */
609 {
610 int tmp = 0;
611 unsigned char val;
612
613 /*
614 * The max we can do is 8192Hz.
615 */
616 if ((arg < 2) || (arg > 8192))
617 return -EINVAL;
618 /*
619 * We don't really want Joe User generating more
620 * than 64Hz of interrupts on a multi-user machine.
621 */
622 if (!kernel && (arg > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE)))
623 return -EACCES;
624
625 while (arg > (1<<tmp))
626 tmp++;
627
628 /*
629 * Check that the input was really a power of 2.
630 */
631 if (arg != (1<<tmp))
632 return -EINVAL;
633
634 spin_lock_irq(&rtc_lock);
635 if (hpet_set_periodic_freq(arg)) {
636 spin_unlock_irq(&rtc_lock);
637 return 0;
638 }
639 rtc_freq = arg;
640
641 val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
642 val |= (16 - tmp);
643 CMOS_WRITE(val, RTC_FREQ_SELECT);
644 spin_unlock_irq(&rtc_lock);
645 return 0;
646 }
647#endif
648 case RTC_EPOCH_READ: /* Read the epoch. */
649 {
650 return put_user (epoch, (unsigned long __user *)arg);
651 }
652 case RTC_EPOCH_SET: /* Set the epoch. */
653 {
654 /*
655 * There were no RTC clocks before 1900.
656 */
657 if (arg < 1900)
658 return -EINVAL;
659
660 if (!capable(CAP_SYS_TIME))
661 return -EACCES;
662
663 epoch = arg;
664 return 0;
665 }
666 default:
667 return -ENOTTY;
668 }
669 return copy_to_user((void __user *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
670}
671
672static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
673 unsigned long arg)
674{
675 return rtc_do_ioctl(cmd, arg, 0);
676}
677
678/*
679 * We enforce only one user at a time here with the open/close.
680 * Also clear the previous interrupt data on an open, and clean
681 * up things on a close.
682 */
683
684/* We use rtc_lock to protect against concurrent opens. So the BKL is not
685 * needed here. Or anywhere else in this driver. */
686static int rtc_open(struct inode *inode, struct file *file)
687{
688 spin_lock_irq (&rtc_lock);
689
690 if(rtc_status & RTC_IS_OPEN)
691 goto out_busy;
692
693 rtc_status |= RTC_IS_OPEN;
694
695 rtc_irq_data = 0;
696 spin_unlock_irq (&rtc_lock);
697 return 0;
698
699out_busy:
700 spin_unlock_irq (&rtc_lock);
701 return -EBUSY;
702}
703
704static int rtc_fasync (int fd, struct file *filp, int on)
705
706{
707 return fasync_helper (fd, filp, on, &rtc_async_queue);
708}
709
710static int rtc_release(struct inode *inode, struct file *file)
711{
712#ifdef RTC_IRQ
713 unsigned char tmp;
714
715 if (rtc_has_irq == 0)
716 goto no_irq;
717
718 /*
719 * Turn off all interrupts once the device is no longer
720 * in use, and clear the data.
721 */
722
723 spin_lock_irq(&rtc_lock);
724 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
725 tmp = CMOS_READ(RTC_CONTROL);
726 tmp &= ~RTC_PIE;
727 tmp &= ~RTC_AIE;
728 tmp &= ~RTC_UIE;
729 CMOS_WRITE(tmp, RTC_CONTROL);
730 CMOS_READ(RTC_INTR_FLAGS);
731 }
732 if (rtc_status & RTC_TIMER_ON) {
733 rtc_status &= ~RTC_TIMER_ON;
734 del_timer(&rtc_irq_timer);
735 }
736 spin_unlock_irq(&rtc_lock);
737
738 if (file->f_flags & FASYNC) {
739 rtc_fasync (-1, file, 0);
740 }
741no_irq:
742#endif
743
744 spin_lock_irq (&rtc_lock);
745 rtc_irq_data = 0;
746 rtc_status &= ~RTC_IS_OPEN;
747 spin_unlock_irq (&rtc_lock);
748 return 0;
749}
750
751#ifdef RTC_IRQ
752/* Called without the kernel lock - fine */
753static unsigned int rtc_poll(struct file *file, poll_table *wait)
754{
755 unsigned long l;
756
757 if (rtc_has_irq == 0)
758 return 0;
759
760 poll_wait(file, &rtc_wait, wait);
761
762 spin_lock_irq (&rtc_lock);
763 l = rtc_irq_data;
764 spin_unlock_irq (&rtc_lock);
765
766 if (l != 0)
767 return POLLIN | POLLRDNORM;
768 return 0;
769}
770#endif
771
772/*
773 * exported stuffs
774 */
775
776EXPORT_SYMBOL(rtc_register);
777EXPORT_SYMBOL(rtc_unregister);
778EXPORT_SYMBOL(rtc_control);
779
780int rtc_register(rtc_task_t *task)
781{
782#ifndef RTC_IRQ
783 return -EIO;
784#else
785 if (task == NULL || task->func == NULL)
786 return -EINVAL;
787 spin_lock_irq(&rtc_lock);
788 if (rtc_status & RTC_IS_OPEN) {
789 spin_unlock_irq(&rtc_lock);
790 return -EBUSY;
791 }
792 spin_lock(&rtc_task_lock);
793 if (rtc_callback) {
794 spin_unlock(&rtc_task_lock);
795 spin_unlock_irq(&rtc_lock);
796 return -EBUSY;
797 }
798 rtc_status |= RTC_IS_OPEN;
799 rtc_callback = task;
800 spin_unlock(&rtc_task_lock);
801 spin_unlock_irq(&rtc_lock);
802 return 0;
803#endif
804}
805
806int rtc_unregister(rtc_task_t *task)
807{
808#ifndef RTC_IRQ
809 return -EIO;
810#else
811 unsigned char tmp;
812
813 spin_lock_irq(&rtc_lock);
814 spin_lock(&rtc_task_lock);
815 if (rtc_callback != task) {
816 spin_unlock(&rtc_task_lock);
817 spin_unlock_irq(&rtc_lock);
818 return -ENXIO;
819 }
820 rtc_callback = NULL;
821
822 /* disable controls */
823 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
824 tmp = CMOS_READ(RTC_CONTROL);
825 tmp &= ~RTC_PIE;
826 tmp &= ~RTC_AIE;
827 tmp &= ~RTC_UIE;
828 CMOS_WRITE(tmp, RTC_CONTROL);
829 CMOS_READ(RTC_INTR_FLAGS);
830 }
831 if (rtc_status & RTC_TIMER_ON) {
832 rtc_status &= ~RTC_TIMER_ON;
833 del_timer(&rtc_irq_timer);
834 }
835 rtc_status &= ~RTC_IS_OPEN;
836 spin_unlock(&rtc_task_lock);
837 spin_unlock_irq(&rtc_lock);
838 return 0;
839#endif
840}
841
842int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
843{
844#ifndef RTC_IRQ
845 return -EIO;
846#else
847 spin_lock_irq(&rtc_task_lock);
848 if (rtc_callback != task) {
849 spin_unlock_irq(&rtc_task_lock);
850 return -ENXIO;
851 }
852 spin_unlock_irq(&rtc_task_lock);
853 return rtc_do_ioctl(cmd, arg, 1);
854#endif
855}
856
857
858/*
859 * The various file operations we support.
860 */
861
862static struct file_operations rtc_fops = {
863 .owner = THIS_MODULE,
864 .llseek = no_llseek,
865 .read = rtc_read,
866#ifdef RTC_IRQ
867 .poll = rtc_poll,
868#endif
869 .ioctl = rtc_ioctl,
870 .open = rtc_open,
871 .release = rtc_release,
872 .fasync = rtc_fasync,
873};
874
875static struct miscdevice rtc_dev = {
876 .minor = RTC_MINOR,
877 .name = "rtc",
878 .fops = &rtc_fops,
879};
880
881static struct file_operations rtc_proc_fops = {
882 .owner = THIS_MODULE,
883 .open = rtc_proc_open,
884 .read = seq_read,
885 .llseek = seq_lseek,
886 .release = single_release,
887};
888
889#if defined(RTC_IRQ) && !defined(__sparc__)
890static irqreturn_t (*rtc_int_handler_ptr)(int irq, void *dev_id, struct pt_regs *regs);
891#endif
892
893static int __init rtc_init(void)
894{
895 struct proc_dir_entry *ent;
896#if defined(__alpha__) || defined(__mips__)
897 unsigned int year, ctrl;
1da177e4
LT		 898 char *guess = NULL;
899#endif
900#ifdef __sparc__
901 struct linux_ebus *ebus;
902 struct linux_ebus_device *edev;
903#ifdef __sparc_v9__
904 struct sparc_isa_bridge *isa_br;
905 struct sparc_isa_device *isa_dev;
906#endif
907#endif
908
909#ifdef __sparc__
910 for_each_ebus(ebus) {
911 for_each_ebusdev(edev, ebus) {
912 if(strcmp(edev->prom_name, "rtc") == 0) {
913 rtc_port = edev->resource[0].start;
914 rtc_irq = edev->irqs[0];
915 goto found;
916 }
917 }
918 }
919#ifdef __sparc_v9__
920 for_each_isa(isa_br) {
921 for_each_isadev(isa_dev, isa_br) {
922 if (strcmp(isa_dev->prom_name, "rtc") == 0) {
923 rtc_port = isa_dev->resource.start;
924 rtc_irq = isa_dev->irq;
925 goto found;
926 }
927 }
928 }
929#endif
930 printk(KERN_ERR "rtc_init: no PC rtc found\n");
931 return -EIO;
932
933found:
934 if (rtc_irq == PCI_IRQ_NONE) {
935 rtc_has_irq = 0;
936 goto no_irq;
937 }
938
939 /*
940 * XXX Interrupt pin #7 in Espresso is shared between RTC and
941 * PCI Slot 2 INTA# (and some INTx# in Slot 1). SA_INTERRUPT here
942 * is asking for trouble with add-on boards. Change to SA_SHIRQ.
943 */
944 if (request_irq(rtc_irq, rtc_interrupt, SA_INTERRUPT, "rtc", (void *)&rtc_port)) {
945 /*
946 * Standard way for sparc to print irq's is to use
947 * __irq_itoa(). I think for EBus it's ok to use %d.
948 */
949 printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq);
950 return -EIO;
951 }
952no_irq:
953#else
954 if (!request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc")) {
955 printk(KERN_ERR "rtc: I/O port %d is not free.\n", RTC_PORT (0));
956 return -EIO;
957 }
958
959#ifdef RTC_IRQ
960 if (is_hpet_enabled()) {
961 rtc_int_handler_ptr = hpet_rtc_interrupt;
962 } else {
963 rtc_int_handler_ptr = rtc_interrupt;
964 }
965
966 if(request_irq(RTC_IRQ, rtc_int_handler_ptr, SA_INTERRUPT, "rtc", NULL)) {
967 /* Yeah right, seeing as irq 8 doesn't even hit the bus. */
968 printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
969 release_region(RTC_PORT(0), RTC_IO_EXTENT);
970 return -EIO;
971 }
972 hpet_rtc_timer_init();
973
974#endif
975
976#endif /* __sparc__ vs. others */
977
978 if (misc_register(&rtc_dev)) {
979#ifdef RTC_IRQ
980 free_irq(RTC_IRQ, NULL);
981#endif
982 release_region(RTC_PORT(0), RTC_IO_EXTENT);
983 return -ENODEV;
984 }
985
986 ent = create_proc_entry("driver/rtc", 0, NULL);
987 if (!ent) {
988#ifdef RTC_IRQ
989 free_irq(RTC_IRQ, NULL);
990#endif
991 release_region(RTC_PORT(0), RTC_IO_EXTENT);
992 misc_deregister(&rtc_dev);
993 return -ENOMEM;
994 }
995 ent->proc_fops = &rtc_proc_fops;
996
997#if defined(__alpha__) || defined(__mips__)
998 rtc_freq = HZ;
999
1000 /* Each operating system on an Alpha uses its own epoch.
1001 Let's try to guess which one we are using now. */
1002
1da177e4 1003 if (rtc_is_updating() != 0)
47f176fd 1004 msleep(20);
1da177e4
LT		 1005
1006 spin_lock_irq(&rtc_lock);
1007 year = CMOS_READ(RTC_YEAR);
1008 ctrl = CMOS_READ(RTC_CONTROL);
1009 spin_unlock_irq(&rtc_lock);
1010
1011 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1012 BCD_TO_BIN(year); /* This should never happen... */
1013
1014 if (year < 20) {
1015 epoch = 2000;
1016 guess = "SRM (post-2000)";
1017 } else if (year >= 20 && year < 48) {
1018 epoch = 1980;
1019 guess = "ARC console";
1020 } else if (year >= 48 && year < 72) {
1021 epoch = 1952;
1022 guess = "Digital UNIX";
1023#if defined(__mips__)
1024 } else if (year >= 72 && year < 74) {
1025 epoch = 2000;
1026 guess = "Digital DECstation";
1027#else
1028 } else if (year >= 70) {
1029 epoch = 1900;
1030 guess = "Standard PC (1900)";
1031#endif
1032 }
1033 if (guess)
1034 printk(KERN_INFO "rtc: %s epoch (%lu) detected\n", guess, epoch);
1035#endif
1036#ifdef RTC_IRQ
1037 if (rtc_has_irq == 0)
1038 goto no_irq2;
1039
1040 init_timer(&rtc_irq_timer);
1041 rtc_irq_timer.function = rtc_dropped_irq;
1042 spin_lock_irq(&rtc_lock);
1043 rtc_freq = 1024;
1044 if (!hpet_set_periodic_freq(rtc_freq)) {
1045 /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */
1046 CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT);
1047 }
1048 spin_unlock_irq(&rtc_lock);
1049no_irq2:
1050#endif
1051
1052 (void) init_sysctl();
1053
1054 printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
1055
1056 return 0;
1057}
1058
1059static void __exit rtc_exit (void)
1060{
1061 cleanup_sysctl();
1062 remove_proc_entry ("driver/rtc", NULL);
1063 misc_deregister(&rtc_dev);
1064
1065#ifdef __sparc__
1066 if (rtc_has_irq)
1067 free_irq (rtc_irq, &rtc_port);
1068#else
1069 release_region (RTC_PORT (0), RTC_IO_EXTENT);
1070#ifdef RTC_IRQ
1071 if (rtc_has_irq)
1072 free_irq (RTC_IRQ, NULL);
1073#endif
1074#endif /* __sparc__ */
1075}
1076
1077module_init(rtc_init);
1078module_exit(rtc_exit);
1079
1080#ifdef RTC_IRQ
1081/*
1082 * At IRQ rates >= 4096Hz, an interrupt may get lost altogether.
1083 * (usually during an IDE disk interrupt, with IRQ unmasking off)
1084 * Since the interrupt handler doesn't get called, the IRQ status
1085 * byte doesn't get read, and the RTC stops generating interrupts.
1086 * A timer is set, and will call this function if/when that happens.
1087 * To get it out of this stalled state, we just read the status.
1088 * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost.
1089 * (You *really* shouldn't be trying to use a non-realtime system
1090 * for something that requires a steady > 1KHz signal anyways.)
1091 */
1092
1093static void rtc_dropped_irq(unsigned long data)
1094{
1095 unsigned long freq;
1096
1097 spin_lock_irq (&rtc_lock);
1098
1099 if (hpet_rtc_dropped_irq()) {
1100 spin_unlock_irq(&rtc_lock);
1101 return;
1102 }
1103
1104 /* Just in case someone disabled the timer from behind our back... */
1105 if (rtc_status & RTC_TIMER_ON)
1106 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
1107
1108 rtc_irq_data += ((rtc_freq/HZ)<<8);
1109 rtc_irq_data &= ~0xff;
1110 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */
1111
1112 freq = rtc_freq;
1113
1114 spin_unlock_irq(&rtc_lock);
1115
1116 printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", freq);
1117
1118 /* Now we have new data */
1119 wake_up_interruptible(&rtc_wait);
1120
1121 kill_fasync (&rtc_async_queue, SIGIO, POLL_IN);
1122}
1123#endif
1124
1125/*
1126 * Info exported via "/proc/driver/rtc".
1127 */
1128
1129static int rtc_proc_show(struct seq_file *seq, void *v)
1130{
1131#define YN(bit) ((ctrl & bit) ? "yes" : "no")
1132#define NY(bit) ((ctrl & bit) ? "no" : "yes")
1133 struct rtc_time tm;
1134 unsigned char batt, ctrl;
1135 unsigned long freq;
1136
1137 spin_lock_irq(&rtc_lock);
1138 batt = CMOS_READ(RTC_VALID) & RTC_VRT;
1139 ctrl = CMOS_READ(RTC_CONTROL);
1140 freq = rtc_freq;
1141 spin_unlock_irq(&rtc_lock);
1142
1143
1144 rtc_get_rtc_time(&tm);
1145
1146 /*
1147 * There is no way to tell if the luser has the RTC set for local
1148 * time or for Universal Standard Time (GMT). Probably local though.
1149 */
1150 seq_printf(seq,
1151 "rtc_time\t: %02d:%02d:%02d\n"
1152 "rtc_date\t: %04d-%02d-%02d\n"
1153 "rtc_epoch\t: %04lu\n",
1154 tm.tm_hour, tm.tm_min, tm.tm_sec,
1155 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
1156
1157 get_rtc_alm_time(&tm);
1158
1159 /*
1160 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
1161 * match any value for that particular field. Values that are
1162 * greater than a valid time, but less than 0xc0 shouldn't appear.
1163 */
1164 seq_puts(seq, "alarm\t\t: ");
1165 if (tm.tm_hour <= 24)
1166 seq_printf(seq, "%02d:", tm.tm_hour);
1167 else
1168 seq_puts(seq, "**:");
1169
1170 if (tm.tm_min <= 59)
1171 seq_printf(seq, "%02d:", tm.tm_min);
1172 else
1173 seq_puts(seq, "**:");
1174
1175 if (tm.tm_sec <= 59)
1176 seq_printf(seq, "%02d\n", tm.tm_sec);
1177 else
1178 seq_puts(seq, "**\n");
1179
1180 seq_printf(seq,
1181 "DST_enable\t: %s\n"
1182 "BCD\t\t: %s\n"
1183 "24hr\t\t: %s\n"
1184 "square_wave\t: %s\n"
1185 "alarm_IRQ\t: %s\n"
1186 "update_IRQ\t: %s\n"
1187 "periodic_IRQ\t: %s\n"
1188 "periodic_freq\t: %ld\n"
1189 "batt_status\t: %s\n",
1190 YN(RTC_DST_EN),
1191 NY(RTC_DM_BINARY),
1192 YN(RTC_24H),
1193 YN(RTC_SQWE),
1194 YN(RTC_AIE),
1195 YN(RTC_UIE),
1196 YN(RTC_PIE),
1197 freq,
1198 batt ? "okay" : "dead");
1199
1200 return 0;
1201#undef YN
1202#undef NY
1203}
1204
1205static int rtc_proc_open(struct inode *inode, struct file *file)
1206{
1207 return single_open(file, rtc_proc_show, NULL);
1208}
1209
1210void rtc_get_rtc_time(struct rtc_time *rtc_tm)
1211{
403fe5ae 1212 unsigned long uip_watchdog = jiffies;
1da177e4
LT		 1213 unsigned char ctrl;
1214#ifdef CONFIG_MACH_DECSTATION
1215 unsigned int real_year;
1216#endif
1217
1218 /*
1219 * read RTC once any update in progress is done. The update
47f176fd 1220 * can take just over 2ms. We wait 20ms. There is no need to
1da177e4
LT		 1221 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
1222 * If you need to know *exactly* when a second has started, enable
1223 * periodic update complete interrupts, (via ioctl) and then
1224 * immediately read /dev/rtc which will block until you get the IRQ.
1225 * Once the read clears, read the RTC time (again via ioctl). Easy.
1226 */
1227
403fe5ae
PV		 1228 while (rtc_is_updating() != 0 && jiffies - uip_watchdog < 2*HZ/100) {
1229 barrier();
1230 cpu_relax();
1231 }
1da177e4
LT		 1232
1233 /*
1234 * Only the values that we read from the RTC are set. We leave
1235 * tm_wday, tm_yday and tm_isdst untouched. Even though the
1236 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
1237 * by the RTC when initially set to a non-zero value.
1238 */
1239 spin_lock_irq(&rtc_lock);
1240 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
1241 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
1242 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
1243 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
1244 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
1245 rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
1246#ifdef CONFIG_MACH_DECSTATION
1247 real_year = CMOS_READ(RTC_DEC_YEAR);
1248#endif
1249 ctrl = CMOS_READ(RTC_CONTROL);
1250 spin_unlock_irq(&rtc_lock);
1251
1252 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1253 {
1254 BCD_TO_BIN(rtc_tm->tm_sec);
1255 BCD_TO_BIN(rtc_tm->tm_min);
1256 BCD_TO_BIN(rtc_tm->tm_hour);
1257 BCD_TO_BIN(rtc_tm->tm_mday);
1258 BCD_TO_BIN(rtc_tm->tm_mon);
1259 BCD_TO_BIN(rtc_tm->tm_year);
1260 }
1261
1262#ifdef CONFIG_MACH_DECSTATION
1263 rtc_tm->tm_year += real_year - 72;
1264#endif
1265
1266 /*
1267 * Account for differences between how the RTC uses the values
1268 * and how they are defined in a struct rtc_time;
1269 */
1270 if ((rtc_tm->tm_year += (epoch - 1900)) <= 69)
1271 rtc_tm->tm_year += 100;
1272
1273 rtc_tm->tm_mon--;
1274}
1275
1276static void get_rtc_alm_time(struct rtc_time *alm_tm)
1277{
1278 unsigned char ctrl;
1279
1280 /*
1281 * Only the values that we read from the RTC are set. That
1282 * means only tm_hour, tm_min, and tm_sec.
1283 */
1284 spin_lock_irq(&rtc_lock);
1285 alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
1286 alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM);
1287 alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM);
1288 ctrl = CMOS_READ(RTC_CONTROL);
1289 spin_unlock_irq(&rtc_lock);
1290
1291 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1292 {
1293 BCD_TO_BIN(alm_tm->tm_sec);
1294 BCD_TO_BIN(alm_tm->tm_min);
1295 BCD_TO_BIN(alm_tm->tm_hour);
1296 }
1297}
1298
1299#ifdef RTC_IRQ
1300/*
1301 * Used to disable/enable interrupts for any one of UIE, AIE, PIE.
1302 * Rumour has it that if you frob the interrupt enable/disable
1303 * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to
1304 * ensure you actually start getting interrupts. Probably for
1305 * compatibility with older/broken chipset RTC implementations.
1306 * We also clear out any old irq data after an ioctl() that
1307 * meddles with the interrupt enable/disable bits.
1308 */
1309
1310static void mask_rtc_irq_bit(unsigned char bit)
1311{
1312 unsigned char val;
1313
1314 spin_lock_irq(&rtc_lock);
1315 if (hpet_mask_rtc_irq_bit(bit)) {
1316 spin_unlock_irq(&rtc_lock);
1317 return;
1318 }
1319 val = CMOS_READ(RTC_CONTROL);
1320 val &= ~bit;
1321 CMOS_WRITE(val, RTC_CONTROL);
1322 CMOS_READ(RTC_INTR_FLAGS);
1323
1324 rtc_irq_data = 0;
1325 spin_unlock_irq(&rtc_lock);
1326}
1327
1328static void set_rtc_irq_bit(unsigned char bit)
1329{
1330 unsigned char val;
1331
1332 spin_lock_irq(&rtc_lock);
1333 if (hpet_set_rtc_irq_bit(bit)) {
1334 spin_unlock_irq(&rtc_lock);
1335 return;
1336 }
1337 val = CMOS_READ(RTC_CONTROL);
1338 val |= bit;
1339 CMOS_WRITE(val, RTC_CONTROL);
1340 CMOS_READ(RTC_INTR_FLAGS);
1341
1342 rtc_irq_data = 0;
1343 spin_unlock_irq(&rtc_lock);
1344}
1345#endif
1346
1347MODULE_AUTHOR("Paul Gortmaker");
1348MODULE_LICENSE("GPL");
1349MODULE_ALIAS_MISCDEV(RTC_MINOR);
kernel source for telekom puls (alcatel/mediatek)