blob: 32dc89720d5896a6f6efebcfdfa8e8999999d85f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01002 * Real Time Clock interface for Linux
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
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
Ingo Molnar5fd1fe92008-01-30 13:31:09 +010020 * interrupts since the last read in the remaining high bytes. The
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 * /dev/rtc interface can also be used with the select(2) call.
22 *
23 * This program is free software; you can redistribute it and/or
24 * modify it under the terms of the GNU General Public License
25 * as published by the Free Software Foundation; either version
26 * 2 of the License, or (at your option) any later version.
27 *
28 * Based on other minimal char device drivers, like Alan's
29 * watchdog, Ted's random, etc. etc.
30 *
31 * 1.07 Paul Gortmaker.
32 * 1.08 Miquel van Smoorenburg: disallow certain things on the
33 * DEC Alpha as the CMOS clock is also used for other things.
34 * 1.09 Nikita Schmidt: epoch support and some Alpha cleanup.
35 * 1.09a Pete Zaitcev: Sun SPARC
36 * 1.09b Jeff Garzik: Modularize, init cleanup
37 * 1.09c Jeff Garzik: SMP cleanup
Ralf Baechle12a0a702006-10-09 23:20:47 +010038 * 1.10 Paul Barton-Davis: add support for async I/O
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 * 1.10a Andrea Arcangeli: Alpha updates
40 * 1.10b Andrew Morton: SMP lock fix
41 * 1.10c Cesar Barros: SMP locking fixes and cleanup
42 * 1.10d Paul Gortmaker: delete paranoia check in rtc_exit
43 * 1.10e Maciej W. Rozycki: Handle DECstation's year weirdness.
Ralf Baechle12a0a702006-10-09 23:20:47 +010044 * 1.11 Takashi Iwai: Kernel access functions
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 * rtc_register/rtc_unregister/rtc_control
46 * 1.11a Daniele Bellucci: Audit create_proc_read_entry in rtc_init
47 * 1.12 Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
48 * CONFIG_HPET_EMULATE_RTC
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -070049 * 1.12a Maciej W. Rozycki: Handle memory-mapped chips properly.
Alan Coxb7599582006-01-11 12:17:32 -080050 * 1.12ac Alan Cox: Allow read access to the day of week register
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 */
52
Alan Coxb7599582006-01-11 12:17:32 -080053#define RTC_VERSION "1.12ac"
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
Linus Torvalds1da177e2005-04-16 15:20:36 -070055/*
56 * Note that *all* calls to CMOS_READ and CMOS_WRITE are done with
57 * interrupts disabled. Due to the index-port/data-port (0x70/0x71)
58 * design of the RTC, we don't want two different things trying to
59 * get to it at once. (e.g. the periodic 11 min sync from time.c vs.
60 * this driver.)
61 */
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063#include <linux/interrupt.h>
64#include <linux/module.h>
65#include <linux/kernel.h>
66#include <linux/types.h>
67#include <linux/miscdevice.h>
68#include <linux/ioport.h>
69#include <linux/fcntl.h>
70#include <linux/mc146818rtc.h>
71#include <linux/init.h>
72#include <linux/poll.h>
73#include <linux/proc_fs.h>
74#include <linux/seq_file.h>
75#include <linux/spinlock.h>
Arnd Bergmann4333dee2008-05-20 19:16:37 +020076#include <linux/smp_lock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070077#include <linux/sysctl.h>
78#include <linux/wait.h>
79#include <linux/bcd.h>
Luca Falavigna47f176f2005-06-28 20:44:42 -070080#include <linux/delay.h>
Alan Cox53f1b142008-07-23 21:30:32 -070081#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83#include <asm/current.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070084#include <asm/system.h>
85
Chris Wright55f93af2007-07-21 17:10:09 +020086#ifdef CONFIG_X86
Linus Torvalds1da177e2005-04-16 15:20:36 -070087#include <asm/hpet.h>
88#endif
89
David S. Millercdee99d2007-07-19 13:59:58 -070090#ifdef CONFIG_SPARC32
David S. Miller75081322008-08-30 00:23:51 -070091#include <linux/of.h>
92#include <linux/of_device.h>
93#include <asm/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
95static unsigned long rtc_port;
David S. Miller75081322008-08-30 00:23:51 -070096static int rtc_irq;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097#endif
98
David Brownell0f4d3fd2008-10-15 22:03:00 -070099#ifdef CONFIG_HPET_EMULATE_RTC
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100#undef RTC_IRQ
101#endif
102
103#ifdef RTC_IRQ
104static int rtc_has_irq = 1;
105#endif
106
107#ifndef CONFIG_HPET_EMULATE_RTC
108#define is_hpet_enabled() 0
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100109#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
David Howells32fa4582008-02-28 13:29:43 +0000115#define hpet_register_irq_handler(h) ({ 0; })
116#define hpet_unregister_irq_handler(h) ({ 0; })
Andrew Morton533ffc22006-12-22 01:06:36 -0800117#ifdef RTC_IRQ
118static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
119{
120 return 0;
121}
122#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123#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
132static struct fasync_struct *rtc_async_queue;
133
134static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
135
136#ifdef RTC_IRQ
Jiri Slaby40565f12007-02-12 00:52:31 -0800137static void rtc_dropped_irq(unsigned long data);
138
139static DEFINE_TIMER(rtc_irq_timer, rtc_dropped_irq, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140#endif
141
142static ssize_t rtc_read(struct file *file, char __user *buf,
143 size_t count, loff_t *ppos);
144
Alan Cox53f1b142008-07-23 21:30:32 -0700145static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
Adrian Bunk9580d852008-07-25 19:46:25 -0700146static void rtc_get_rtc_time(struct rtc_time *rtc_tm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
148#ifdef RTC_IRQ
149static unsigned int rtc_poll(struct file *file, poll_table *wait);
150#endif
151
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100152static void get_rtc_alm_time(struct rtc_time *alm_tm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153#ifdef RTC_IRQ
Takashi Iwaic3348762005-11-07 11:14:57 +0100154static void set_rtc_irq_bit_locked(unsigned char bit);
155static void mask_rtc_irq_bit_locked(unsigned char bit);
156
157static 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
164static 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}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170#endif
171
Jan Beulich9cef7792006-12-13 00:35:05 -0800172#ifdef CONFIG_PROC_FS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173static int rtc_proc_open(struct inode *inode, struct file *file);
Jan Beulich9cef7792006-12-13 00:35:05 -0800174#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
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 big kernel lock. However, ioctl can still disable the timer
186 * 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 */
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100190static unsigned long rtc_status; /* bitmapped status byte. */
191static unsigned long rtc_freq; /* Current periodic IRQ rate */
192static unsigned long rtc_irq_data; /* our output to the world */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193static 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 */
199static DEFINE_SPINLOCK(rtc_task_lock);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100200static rtc_task_t *rtc_callback;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201#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
208static unsigned long epoch = 1900; /* year corresponding to 0x00 */
209
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100210static const unsigned char days_in_mo[] =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211{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 */
216static inline unsigned char rtc_is_updating(void)
217{
Peter Zijlstra0b16f212006-09-25 16:24:23 -0700218 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 unsigned char uip;
220
Peter Zijlstra0b16f212006-09-25 16:24:23 -0700221 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
Peter Zijlstra0b16f212006-09-25 16:24:23 -0700223 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 return uip;
225}
226
227#ifdef RTC_IRQ
228/*
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -0700229 * A very tiny interrupt handler. It runs with IRQF_DISABLED set,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 * 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
Adrian Bunk9580d852008-07-25 19:46:25 -0700238static irqreturn_t rtc_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239{
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
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100247 spin_lock(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 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
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100264 spin_unlock(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
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);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100271 wake_up_interruptible(&rtc_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100273 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275 return IRQ_HANDLED;
276}
277#endif
278
279/*
280 * sysctl-tuning infrastructure.
281 */
282static ctl_table rtc_table[] = {
283 {
Eric W. Biederman77353622007-02-14 00:33:52 -0800284 .ctl_name = CTL_UNNUMBERED,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 .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
294static ctl_table rtc_root[] = {
295 {
Eric W. Biederman77353622007-02-14 00:33:52 -0800296 .ctl_name = CTL_UNNUMBERED,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 .procname = "rtc",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 .mode = 0555,
299 .child = rtc_table,
300 },
301 { .ctl_name = 0 }
302};
303
304static ctl_table dev_root[] = {
305 {
306 .ctl_name = CTL_DEV,
307 .procname = "dev",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 .mode = 0555,
309 .child = rtc_root,
310 },
311 { .ctl_name = 0 }
312};
313
314static struct ctl_table_header *sysctl_header;
315
316static int __init init_sysctl(void)
317{
Eric W. Biederman0b4d4142007-02-14 00:34:09 -0800318 sysctl_header = register_sysctl_table(dev_root);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 return 0;
320}
321
322static 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
331static 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;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100340
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 if (rtc_has_irq == 0)
342 return -EIO;
343
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700344 /*
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))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 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);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100363
364 spin_lock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 data = rtc_irq_data;
366 rtc_irq_data = 0;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100367 spin_unlock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368
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
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100383 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 }
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700390 if (!retval)
391 retval = count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 out:
Milind Arun Choudharycc0a8fb2007-05-08 00:30:52 -0700393 __set_current_state(TASK_RUNNING);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 remove_wait_queue(&rtc_wait, &wait);
395
396 return retval;
397#endif
398}
399
400static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
401{
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100402 struct rtc_time wtime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
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 {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100434 /* can be called from isr via rtc_control() */
435 unsigned long flags;
436
437 spin_lock_irqsave(&rtc_lock, flags);
Takashi Iwaic3348762005-11-07 11:14:57 +0100438 mask_rtc_irq_bit_locked(RTC_PIE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 if (rtc_status & RTC_TIMER_ON) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 rtc_status &= ~RTC_TIMER_ON;
441 del_timer(&rtc_irq_timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 }
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100443 spin_unlock_irqrestore(&rtc_lock, flags);
444
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 return 0;
446 }
447 case RTC_PIE_ON: /* Allow periodic ints */
448 {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100449 /* can be called from isr via rtc_control() */
450 unsigned long flags;
451
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 /*
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) &&
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100457 (!capable(CAP_SYS_RESOURCE)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 return -EACCES;
459
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100460 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 if (!(rtc_status & RTC_TIMER_ON)) {
Jiri Slaby40565f12007-02-12 00:52:31 -0800462 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq +
463 2*HZ/100);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 rtc_status |= RTC_TIMER_ON;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 }
Takashi Iwaic3348762005-11-07 11:14:57 +0100466 set_rtc_irq_bit_locked(RTC_PIE);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100467 spin_unlock_irqrestore(&rtc_lock, flags);
468
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 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);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100491 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 }
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) ||
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100519 RTC_ALWAYS_BCD) {
520 if (sec < 60)
Adrian Bunk357c6e62008-10-18 20:28:42 -0700521 sec = bin2bcd(sec);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100522 else
523 sec = 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100525 if (min < 60)
Adrian Bunk357c6e62008-10-18 20:28:42 -0700526 min = bin2bcd(min);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100527 else
528 min = 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100530 if (hrs < 24)
Adrian Bunk357c6e62008-10-18 20:28:42 -0700531 hrs = bin2bcd(hrs);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100532 else
533 hrs = 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 }
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;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100582
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
584 return -EINVAL;
585
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100586 yrs -= epoch;
587 if (yrs > 255) /* They are unsigned */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 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) {
Adrian Bunk357c6e62008-10-18 20:28:42 -0700617 sec = bin2bcd(sec);
618 min = bin2bcd(min);
619 hrs = bin2bcd(hrs);
620 day = bin2bcd(day);
621 mon = bin2bcd(mon);
622 yrs = bin2bcd(yrs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 }
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;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100655 /* can be called from isr via rtc_control() */
656 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100658 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 * 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 */
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100667 if (!kernel && (arg > rtc_max_user_freq) &&
668 !capable(CAP_SYS_RESOURCE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 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
Paul Gortmaker61ca9da2008-07-10 17:30:48 -0700680 rtc_freq = arg;
681
Takashi Iwaic3348762005-11-07 11:14:57 +0100682 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 if (hpet_set_periodic_freq(arg)) {
Takashi Iwaic3348762005-11-07 11:14:57 +0100684 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 return 0;
686 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687
688 val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
689 val |= (16 - tmp);
690 CMOS_WRITE(val, RTC_FREQ_SELECT);
Takashi Iwaic3348762005-11-07 11:14:57 +0100691 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 return 0;
693 }
694#endif
695 case RTC_EPOCH_READ: /* Read the epoch. */
696 {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100697 return put_user(epoch, (unsigned long __user *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 }
699 case RTC_EPOCH_SET: /* Set the epoch. */
700 {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100701 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 * 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 }
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100716 return copy_to_user((void __user *)arg,
717 &wtime, sizeof wtime) ? -EFAULT : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718}
719
Alan Cox53f1b142008-07-23 21:30:32 -0700720static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721{
Alan Cox53f1b142008-07-23 21:30:32 -0700722 long ret;
723 lock_kernel();
724 ret = rtc_do_ioctl(cmd, arg, 0);
725 unlock_kernel();
726 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727}
728
729/*
730 * We enforce only one user at a time here with the open/close.
731 * Also clear the previous interrupt data on an open, and clean
732 * up things on a close.
733 */
734
735/* We use rtc_lock to protect against concurrent opens. So the BKL is not
736 * needed here. Or anywhere else in this driver. */
737static int rtc_open(struct inode *inode, struct file *file)
738{
Arnd Bergmann4333dee2008-05-20 19:16:37 +0200739 lock_kernel();
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100740 spin_lock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100742 if (rtc_status & RTC_IS_OPEN)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 goto out_busy;
744
745 rtc_status |= RTC_IS_OPEN;
746
747 rtc_irq_data = 0;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100748 spin_unlock_irq(&rtc_lock);
Arnd Bergmann4333dee2008-05-20 19:16:37 +0200749 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 return 0;
751
752out_busy:
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100753 spin_unlock_irq(&rtc_lock);
Arnd Bergmann4333dee2008-05-20 19:16:37 +0200754 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 return -EBUSY;
756}
757
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100758static int rtc_fasync(int fd, struct file *filp, int on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759{
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100760 return fasync_helper(fd, filp, on, &rtc_async_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761}
762
763static int rtc_release(struct inode *inode, struct file *file)
764{
765#ifdef RTC_IRQ
766 unsigned char tmp;
767
768 if (rtc_has_irq == 0)
769 goto no_irq;
770
771 /*
772 * Turn off all interrupts once the device is no longer
773 * in use, and clear the data.
774 */
775
776 spin_lock_irq(&rtc_lock);
777 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
778 tmp = CMOS_READ(RTC_CONTROL);
779 tmp &= ~RTC_PIE;
780 tmp &= ~RTC_AIE;
781 tmp &= ~RTC_UIE;
782 CMOS_WRITE(tmp, RTC_CONTROL);
783 CMOS_READ(RTC_INTR_FLAGS);
784 }
785 if (rtc_status & RTC_TIMER_ON) {
786 rtc_status &= ~RTC_TIMER_ON;
787 del_timer(&rtc_irq_timer);
788 }
789 spin_unlock_irq(&rtc_lock);
790
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100791 if (file->f_flags & FASYNC)
792 rtc_fasync(-1, file, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793no_irq:
794#endif
795
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100796 spin_lock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 rtc_irq_data = 0;
798 rtc_status &= ~RTC_IS_OPEN;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100799 spin_unlock_irq(&rtc_lock);
800
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 return 0;
802}
803
804#ifdef RTC_IRQ
805/* Called without the kernel lock - fine */
806static unsigned int rtc_poll(struct file *file, poll_table *wait)
807{
808 unsigned long l;
809
810 if (rtc_has_irq == 0)
811 return 0;
812
813 poll_wait(file, &rtc_wait, wait);
814
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100815 spin_lock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 l = rtc_irq_data;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100817 spin_unlock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818
819 if (l != 0)
820 return POLLIN | POLLRDNORM;
821 return 0;
822}
823#endif
824
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825int rtc_register(rtc_task_t *task)
826{
827#ifndef RTC_IRQ
828 return -EIO;
829#else
830 if (task == NULL || task->func == NULL)
831 return -EINVAL;
832 spin_lock_irq(&rtc_lock);
833 if (rtc_status & RTC_IS_OPEN) {
834 spin_unlock_irq(&rtc_lock);
835 return -EBUSY;
836 }
837 spin_lock(&rtc_task_lock);
838 if (rtc_callback) {
839 spin_unlock(&rtc_task_lock);
840 spin_unlock_irq(&rtc_lock);
841 return -EBUSY;
842 }
843 rtc_status |= RTC_IS_OPEN;
844 rtc_callback = task;
845 spin_unlock(&rtc_task_lock);
846 spin_unlock_irq(&rtc_lock);
847 return 0;
848#endif
849}
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100850EXPORT_SYMBOL(rtc_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851
852int rtc_unregister(rtc_task_t *task)
853{
854#ifndef RTC_IRQ
855 return -EIO;
856#else
857 unsigned char tmp;
858
859 spin_lock_irq(&rtc_lock);
860 spin_lock(&rtc_task_lock);
861 if (rtc_callback != task) {
862 spin_unlock(&rtc_task_lock);
863 spin_unlock_irq(&rtc_lock);
864 return -ENXIO;
865 }
866 rtc_callback = NULL;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100867
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 /* disable controls */
869 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
870 tmp = CMOS_READ(RTC_CONTROL);
871 tmp &= ~RTC_PIE;
872 tmp &= ~RTC_AIE;
873 tmp &= ~RTC_UIE;
874 CMOS_WRITE(tmp, RTC_CONTROL);
875 CMOS_READ(RTC_INTR_FLAGS);
876 }
877 if (rtc_status & RTC_TIMER_ON) {
878 rtc_status &= ~RTC_TIMER_ON;
879 del_timer(&rtc_irq_timer);
880 }
881 rtc_status &= ~RTC_IS_OPEN;
882 spin_unlock(&rtc_task_lock);
883 spin_unlock_irq(&rtc_lock);
884 return 0;
885#endif
886}
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100887EXPORT_SYMBOL(rtc_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888
889int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
890{
891#ifndef RTC_IRQ
892 return -EIO;
893#else
Takashi Iwaic3348762005-11-07 11:14:57 +0100894 unsigned long flags;
895 if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET)
896 return -EINVAL;
897 spin_lock_irqsave(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 if (rtc_callback != task) {
Takashi Iwaic3348762005-11-07 11:14:57 +0100899 spin_unlock_irqrestore(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 return -ENXIO;
901 }
Takashi Iwaic3348762005-11-07 11:14:57 +0100902 spin_unlock_irqrestore(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 return rtc_do_ioctl(cmd, arg, 1);
904#endif
905}
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100906EXPORT_SYMBOL(rtc_control);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907
908/*
909 * The various file operations we support.
910 */
911
Arjan van de Ven62322d22006-07-03 00:24:21 -0700912static const struct file_operations rtc_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 .owner = THIS_MODULE,
914 .llseek = no_llseek,
915 .read = rtc_read,
916#ifdef RTC_IRQ
917 .poll = rtc_poll,
918#endif
Alan Cox53f1b142008-07-23 21:30:32 -0700919 .unlocked_ioctl = rtc_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 .open = rtc_open,
921 .release = rtc_release,
922 .fasync = rtc_fasync,
923};
924
925static struct miscdevice rtc_dev = {
926 .minor = RTC_MINOR,
927 .name = "rtc",
928 .fops = &rtc_fops,
929};
930
Jan Beulich9cef7792006-12-13 00:35:05 -0800931#ifdef CONFIG_PROC_FS
Arjan van de Ven62322d22006-07-03 00:24:21 -0700932static const struct file_operations rtc_proc_fops = {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100933 .owner = THIS_MODULE,
934 .open = rtc_proc_open,
935 .read = seq_read,
936 .llseek = seq_lseek,
937 .release = single_release,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939#endif
940
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -0800941static resource_size_t rtc_size;
942
943static struct resource * __init rtc_request_region(resource_size_t size)
944{
945 struct resource *r;
946
947 if (RTC_IOMAPPED)
948 r = request_region(RTC_PORT(0), size, "rtc");
949 else
950 r = request_mem_region(RTC_PORT(0), size, "rtc");
951
952 if (r)
953 rtc_size = size;
954
955 return r;
956}
957
Bjorn Helgaas4c06be12007-11-14 16:59:56 -0800958static void rtc_release_region(void)
959{
960 if (RTC_IOMAPPED)
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -0800961 release_region(RTC_PORT(0), rtc_size);
Bjorn Helgaas4c06be12007-11-14 16:59:56 -0800962 else
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -0800963 release_mem_region(RTC_PORT(0), rtc_size);
Bjorn Helgaas4c06be12007-11-14 16:59:56 -0800964}
965
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966static int __init rtc_init(void)
967{
Jan Beulich9cef7792006-12-13 00:35:05 -0800968#ifdef CONFIG_PROC_FS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 struct proc_dir_entry *ent;
Jan Beulich9cef7792006-12-13 00:35:05 -0800970#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971#if defined(__alpha__) || defined(__mips__)
972 unsigned int year, ctrl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973 char *guess = NULL;
974#endif
David S. Millercdee99d2007-07-19 13:59:58 -0700975#ifdef CONFIG_SPARC32
David S. Miller75081322008-08-30 00:23:51 -0700976 struct device_node *ebus_dp;
977 struct of_device *op;
Jan Beulich9cef7792006-12-13 00:35:05 -0800978#else
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700979 void *r;
Jan Beulich9cef7792006-12-13 00:35:05 -0800980#ifdef RTC_IRQ
981 irq_handler_t rtc_int_handler_ptr;
982#endif
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700983#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984
David S. Millercdee99d2007-07-19 13:59:58 -0700985#ifdef CONFIG_SPARC32
David S. Miller75081322008-08-30 00:23:51 -0700986 for_each_node_by_name(ebus_dp, "ebus") {
987 struct device_node *dp;
988 for (dp = ebus_dp; dp; dp = dp->sibling) {
989 if (!strcmp(dp->name, "rtc")) {
990 op = of_find_device_by_node(dp);
991 if (op) {
992 rtc_port = op->resource[0].start;
993 rtc_irq = op->irqs[0];
994 goto found;
995 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 }
997 }
998 }
Jan Beulichf3e92d32006-12-13 00:35:04 -0800999 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 printk(KERN_ERR "rtc_init: no PC rtc found\n");
1001 return -EIO;
1002
1003found:
David S. Miller75081322008-08-30 00:23:51 -07001004 if (!rtc_irq) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 rtc_has_irq = 0;
1006 goto no_irq;
1007 }
1008
1009 /*
1010 * XXX Interrupt pin #7 in Espresso is shared between RTC and
David S. Miller53d0fc22005-09-05 23:33:05 -07001011 * PCI Slot 2 INTA# (and some INTx# in Slot 1).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 */
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001013 if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc",
1014 (void *)&rtc_port)) {
Jan Beulichf3e92d32006-12-13 00:35:04 -08001015 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq);
1017 return -EIO;
1018 }
1019no_irq:
1020#else
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -08001021 r = rtc_request_region(RTC_IO_EXTENT);
1022
1023 /*
1024 * If we've already requested a smaller range (for example, because
1025 * PNPBIOS or ACPI told us how the device is configured), the request
1026 * above might fail because it's too big.
1027 *
1028 * If so, request just the range we actually use.
1029 */
1030 if (!r)
1031 r = rtc_request_region(RTC_IO_EXTENT_USED);
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -07001032 if (!r) {
Jan Beulichf3e92d32006-12-13 00:35:04 -08001033#ifdef RTC_IRQ
1034 rtc_has_irq = 0;
1035#endif
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -07001036 printk(KERN_ERR "rtc: I/O resource %lx is not free.\n",
1037 (long)(RTC_PORT(0)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 return -EIO;
1039 }
1040
1041#ifdef RTC_IRQ
1042 if (is_hpet_enabled()) {
Bernhard Wallef8f76482008-01-30 13:33:31 +01001043 int err;
1044
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045 rtc_int_handler_ptr = hpet_rtc_interrupt;
Bernhard Wallef8f76482008-01-30 13:33:31 +01001046 err = hpet_register_irq_handler(rtc_interrupt);
1047 if (err != 0) {
1048 printk(KERN_WARNING "hpet_register_irq_handler failed "
1049 "in rtc_init().");
1050 return err;
1051 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 } else {
1053 rtc_int_handler_ptr = rtc_interrupt;
1054 }
1055
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001056 if (request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED,
1057 "rtc", NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 /* Yeah right, seeing as irq 8 doesn't even hit the bus. */
Jan Beulichf3e92d32006-12-13 00:35:04 -08001059 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060 printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
Bjorn Helgaas4c06be12007-11-14 16:59:56 -08001061 rtc_release_region();
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001062
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063 return -EIO;
1064 }
1065 hpet_rtc_timer_init();
1066
1067#endif
1068
David S. Millercdee99d2007-07-19 13:59:58 -07001069#endif /* CONFIG_SPARC32 vs. others */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070
1071 if (misc_register(&rtc_dev)) {
1072#ifdef RTC_IRQ
1073 free_irq(RTC_IRQ, NULL);
Bernhard Wallef8f76482008-01-30 13:33:31 +01001074 hpet_unregister_irq_handler(rtc_interrupt);
Jan Beulichf3e92d32006-12-13 00:35:04 -08001075 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076#endif
Bjorn Helgaas4c06be12007-11-14 16:59:56 -08001077 rtc_release_region();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078 return -ENODEV;
1079 }
1080
Jan Beulich9cef7792006-12-13 00:35:05 -08001081#ifdef CONFIG_PROC_FS
Denis V. Lunev1b502212008-04-29 01:02:34 -07001082 ent = proc_create("driver/rtc", 0, NULL, &rtc_proc_fops);
1083 if (!ent)
Jan Beulich9cef7792006-12-13 00:35:05 -08001084 printk(KERN_WARNING "rtc: Failed to register with procfs.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086
1087#if defined(__alpha__) || defined(__mips__)
1088 rtc_freq = HZ;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001089
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090 /* Each operating system on an Alpha uses its own epoch.
1091 Let's try to guess which one we are using now. */
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001092
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 if (rtc_is_updating() != 0)
Luca Falavigna47f176f2005-06-28 20:44:42 -07001094 msleep(20);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001095
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096 spin_lock_irq(&rtc_lock);
1097 year = CMOS_READ(RTC_YEAR);
1098 ctrl = CMOS_READ(RTC_CONTROL);
1099 spin_unlock_irq(&rtc_lock);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001100
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
Adrian Bunk357c6e62008-10-18 20:28:42 -07001102 year = bcd2bin(year); /* This should never happen... */
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001103
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104 if (year < 20) {
1105 epoch = 2000;
1106 guess = "SRM (post-2000)";
1107 } else if (year >= 20 && year < 48) {
1108 epoch = 1980;
1109 guess = "ARC console";
1110 } else if (year >= 48 && year < 72) {
1111 epoch = 1952;
1112 guess = "Digital UNIX";
1113#if defined(__mips__)
1114 } else if (year >= 72 && year < 74) {
1115 epoch = 2000;
1116 guess = "Digital DECstation";
1117#else
1118 } else if (year >= 70) {
1119 epoch = 1900;
1120 guess = "Standard PC (1900)";
1121#endif
1122 }
1123 if (guess)
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001124 printk(KERN_INFO "rtc: %s epoch (%lu) detected\n",
1125 guess, epoch);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126#endif
1127#ifdef RTC_IRQ
1128 if (rtc_has_irq == 0)
1129 goto no_irq2;
1130
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131 spin_lock_irq(&rtc_lock);
1132 rtc_freq = 1024;
1133 if (!hpet_set_periodic_freq(rtc_freq)) {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001134 /*
1135 * Initialize periodic frequency to CMOS reset default,
1136 * which is 1024Hz
1137 */
1138 CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06),
1139 RTC_FREQ_SELECT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140 }
1141 spin_unlock_irq(&rtc_lock);
1142no_irq2:
1143#endif
1144
1145 (void) init_sysctl();
1146
1147 printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
1148
1149 return 0;
1150}
1151
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001152static void __exit rtc_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153{
1154 cleanup_sysctl();
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001155 remove_proc_entry("driver/rtc", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 misc_deregister(&rtc_dev);
1157
David S. Millercdee99d2007-07-19 13:59:58 -07001158#ifdef CONFIG_SPARC32
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159 if (rtc_has_irq)
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001160 free_irq(rtc_irq, &rtc_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161#else
Bjorn Helgaas4c06be12007-11-14 16:59:56 -08001162 rtc_release_region();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163#ifdef RTC_IRQ
Bernhard Wallef8f76482008-01-30 13:33:31 +01001164 if (rtc_has_irq) {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001165 free_irq(RTC_IRQ, NULL);
Bernhard Wallef8f76482008-01-30 13:33:31 +01001166 hpet_unregister_irq_handler(hpet_rtc_interrupt);
1167 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168#endif
David S. Millercdee99d2007-07-19 13:59:58 -07001169#endif /* CONFIG_SPARC32 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170}
1171
1172module_init(rtc_init);
1173module_exit(rtc_exit);
1174
1175#ifdef RTC_IRQ
1176/*
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001177 * At IRQ rates >= 4096Hz, an interrupt may get lost altogether.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178 * (usually during an IDE disk interrupt, with IRQ unmasking off)
1179 * Since the interrupt handler doesn't get called, the IRQ status
1180 * byte doesn't get read, and the RTC stops generating interrupts.
1181 * A timer is set, and will call this function if/when that happens.
1182 * To get it out of this stalled state, we just read the status.
1183 * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost.
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001184 * (You *really* shouldn't be trying to use a non-realtime system
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 * for something that requires a steady > 1KHz signal anyways.)
1186 */
1187
1188static void rtc_dropped_irq(unsigned long data)
1189{
1190 unsigned long freq;
1191
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001192 spin_lock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193
1194 if (hpet_rtc_dropped_irq()) {
1195 spin_unlock_irq(&rtc_lock);
1196 return;
1197 }
1198
1199 /* Just in case someone disabled the timer from behind our back... */
1200 if (rtc_status & RTC_TIMER_ON)
1201 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
1202
1203 rtc_irq_data += ((rtc_freq/HZ)<<8);
1204 rtc_irq_data &= ~0xff;
1205 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */
1206
1207 freq = rtc_freq;
1208
1209 spin_unlock_irq(&rtc_lock);
1210
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001211 if (printk_ratelimit()) {
1212 printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n",
1213 freq);
1214 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215
1216 /* Now we have new data */
1217 wake_up_interruptible(&rtc_wait);
1218
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001219 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220}
1221#endif
1222
Jan Beulich9cef7792006-12-13 00:35:05 -08001223#ifdef CONFIG_PROC_FS
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224/*
1225 * Info exported via "/proc/driver/rtc".
1226 */
1227
1228static int rtc_proc_show(struct seq_file *seq, void *v)
1229{
1230#define YN(bit) ((ctrl & bit) ? "yes" : "no")
1231#define NY(bit) ((ctrl & bit) ? "no" : "yes")
1232 struct rtc_time tm;
1233 unsigned char batt, ctrl;
1234 unsigned long freq;
1235
1236 spin_lock_irq(&rtc_lock);
1237 batt = CMOS_READ(RTC_VALID) & RTC_VRT;
1238 ctrl = CMOS_READ(RTC_CONTROL);
1239 freq = rtc_freq;
1240 spin_unlock_irq(&rtc_lock);
1241
1242
1243 rtc_get_rtc_time(&tm);
1244
1245 /*
1246 * There is no way to tell if the luser has the RTC set for local
1247 * time or for Universal Standard Time (GMT). Probably local though.
1248 */
1249 seq_printf(seq,
1250 "rtc_time\t: %02d:%02d:%02d\n"
1251 "rtc_date\t: %04d-%02d-%02d\n"
1252 "rtc_epoch\t: %04lu\n",
1253 tm.tm_hour, tm.tm_min, tm.tm_sec,
1254 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
1255
1256 get_rtc_alm_time(&tm);
1257
1258 /*
1259 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
1260 * match any value for that particular field. Values that are
1261 * greater than a valid time, but less than 0xc0 shouldn't appear.
1262 */
1263 seq_puts(seq, "alarm\t\t: ");
1264 if (tm.tm_hour <= 24)
1265 seq_printf(seq, "%02d:", tm.tm_hour);
1266 else
1267 seq_puts(seq, "**:");
1268
1269 if (tm.tm_min <= 59)
1270 seq_printf(seq, "%02d:", tm.tm_min);
1271 else
1272 seq_puts(seq, "**:");
1273
1274 if (tm.tm_sec <= 59)
1275 seq_printf(seq, "%02d\n", tm.tm_sec);
1276 else
1277 seq_puts(seq, "**\n");
1278
1279 seq_printf(seq,
1280 "DST_enable\t: %s\n"
1281 "BCD\t\t: %s\n"
1282 "24hr\t\t: %s\n"
1283 "square_wave\t: %s\n"
1284 "alarm_IRQ\t: %s\n"
1285 "update_IRQ\t: %s\n"
1286 "periodic_IRQ\t: %s\n"
1287 "periodic_freq\t: %ld\n"
1288 "batt_status\t: %s\n",
1289 YN(RTC_DST_EN),
1290 NY(RTC_DM_BINARY),
1291 YN(RTC_24H),
1292 YN(RTC_SQWE),
1293 YN(RTC_AIE),
1294 YN(RTC_UIE),
1295 YN(RTC_PIE),
1296 freq,
1297 batt ? "okay" : "dead");
1298
1299 return 0;
1300#undef YN
1301#undef NY
1302}
1303
1304static int rtc_proc_open(struct inode *inode, struct file *file)
1305{
1306 return single_open(file, rtc_proc_show, NULL);
1307}
Jan Beulich9cef7792006-12-13 00:35:05 -08001308#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309
Adrian Bunk9580d852008-07-25 19:46:25 -07001310static void rtc_get_rtc_time(struct rtc_time *rtc_tm)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311{
Ingo Molnar0f749642006-07-12 09:03:10 -07001312 unsigned long uip_watchdog = jiffies, flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313 unsigned char ctrl;
1314#ifdef CONFIG_MACH_DECSTATION
1315 unsigned int real_year;
1316#endif
1317
1318 /*
1319 * read RTC once any update in progress is done. The update
Luca Falavigna47f176f2005-06-28 20:44:42 -07001320 * can take just over 2ms. We wait 20ms. There is no need to
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
1322 * If you need to know *exactly* when a second has started, enable
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001323 * periodic update complete interrupts, (via ioctl) and then
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324 * immediately read /dev/rtc which will block until you get the IRQ.
1325 * Once the read clears, read the RTC time (again via ioctl). Easy.
1326 */
1327
Julia Lawalldca03a52008-04-28 02:11:59 -07001328 while (rtc_is_updating() != 0 &&
1329 time_before(jiffies, uip_watchdog + 2*HZ/100))
Petr Vandrovec403fe5a2005-08-05 15:50:07 +02001330 cpu_relax();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331
1332 /*
1333 * Only the values that we read from the RTC are set. We leave
Alan Coxb7599582006-01-11 12:17:32 -08001334 * tm_wday, tm_yday and tm_isdst untouched. Note that while the
1335 * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is
1336 * only updated by the RTC when initially set to a non-zero value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 */
Ingo Molnar0f749642006-07-12 09:03:10 -07001338 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
1340 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
1341 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
1342 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
1343 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
1344 rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
Alan Coxb7599582006-01-11 12:17:32 -08001345 /* Only set from 2.6.16 onwards */
1346 rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK);
1347
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348#ifdef CONFIG_MACH_DECSTATION
1349 real_year = CMOS_READ(RTC_DEC_YEAR);
1350#endif
1351 ctrl = CMOS_READ(RTC_CONTROL);
Ingo Molnar0f749642006-07-12 09:03:10 -07001352 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001354 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
Adrian Bunk357c6e62008-10-18 20:28:42 -07001355 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
1356 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
1357 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
1358 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
1359 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
1360 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
1361 rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 }
1363
1364#ifdef CONFIG_MACH_DECSTATION
1365 rtc_tm->tm_year += real_year - 72;
1366#endif
1367
1368 /*
1369 * Account for differences between how the RTC uses the values
1370 * and how they are defined in a struct rtc_time;
1371 */
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001372 rtc_tm->tm_year += epoch - 1900;
1373 if (rtc_tm->tm_year <= 69)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374 rtc_tm->tm_year += 100;
1375
1376 rtc_tm->tm_mon--;
1377}
1378
1379static void get_rtc_alm_time(struct rtc_time *alm_tm)
1380{
1381 unsigned char ctrl;
1382
1383 /*
1384 * Only the values that we read from the RTC are set. That
1385 * means only tm_hour, tm_min, and tm_sec.
1386 */
1387 spin_lock_irq(&rtc_lock);
1388 alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
1389 alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM);
1390 alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM);
1391 ctrl = CMOS_READ(RTC_CONTROL);
1392 spin_unlock_irq(&rtc_lock);
1393
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001394 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
Adrian Bunk357c6e62008-10-18 20:28:42 -07001395 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
1396 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
1397 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 }
1399}
1400
1401#ifdef RTC_IRQ
1402/*
1403 * Used to disable/enable interrupts for any one of UIE, AIE, PIE.
1404 * Rumour has it that if you frob the interrupt enable/disable
1405 * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to
1406 * ensure you actually start getting interrupts. Probably for
1407 * compatibility with older/broken chipset RTC implementations.
1408 * We also clear out any old irq data after an ioctl() that
1409 * meddles with the interrupt enable/disable bits.
1410 */
1411
Takashi Iwaic3348762005-11-07 11:14:57 +01001412static void mask_rtc_irq_bit_locked(unsigned char bit)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413{
1414 unsigned char val;
1415
Takashi Iwaic3348762005-11-07 11:14:57 +01001416 if (hpet_mask_rtc_irq_bit(bit))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418 val = CMOS_READ(RTC_CONTROL);
1419 val &= ~bit;
1420 CMOS_WRITE(val, RTC_CONTROL);
1421 CMOS_READ(RTC_INTR_FLAGS);
1422
1423 rtc_irq_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424}
1425
Takashi Iwaic3348762005-11-07 11:14:57 +01001426static void set_rtc_irq_bit_locked(unsigned char bit)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427{
1428 unsigned char val;
1429
Takashi Iwaic3348762005-11-07 11:14:57 +01001430 if (hpet_set_rtc_irq_bit(bit))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001432 val = CMOS_READ(RTC_CONTROL);
1433 val |= bit;
1434 CMOS_WRITE(val, RTC_CONTROL);
1435 CMOS_READ(RTC_INTR_FLAGS);
1436
1437 rtc_irq_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438}
1439#endif
1440
1441MODULE_AUTHOR("Paul Gortmaker");
1442MODULE_LICENSE("GPL");
1443MODULE_ALIAS_MISCDEV(RTC_MINOR);