blob: 78b151c4d20f94b0bccecc1acb3540e14b77cdc9 [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>
76#include <linux/sysctl.h>
77#include <linux/wait.h>
78#include <linux/bcd.h>
Luca Falavigna47f176f2005-06-28 20:44:42 -070079#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81#include <asm/current.h>
82#include <asm/uaccess.h>
83#include <asm/system.h>
84
Chris Wright55f93af2007-07-21 17:10:09 +020085#ifdef CONFIG_X86
Linus Torvalds1da177e2005-04-16 15:20:36 -070086#include <asm/hpet.h>
87#endif
88
David S. Millercdee99d2007-07-19 13:59:58 -070089#ifdef CONFIG_SPARC32
Linus Torvalds1da177e2005-04-16 15:20:36 -070090#include <linux/pci.h>
91#include <asm/ebus.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93static unsigned long rtc_port;
94static int rtc_irq = PCI_IRQ_NONE;
95#endif
96
97#ifdef CONFIG_HPET_RTC_IRQ
98#undef RTC_IRQ
99#endif
100
101#ifdef RTC_IRQ
102static int rtc_has_irq = 1;
103#endif
104
105#ifndef CONFIG_HPET_EMULATE_RTC
106#define is_hpet_enabled() 0
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100107#define hpet_set_alarm_time(hrs, min, sec) 0
108#define hpet_set_periodic_freq(arg) 0
109#define hpet_mask_rtc_irq_bit(arg) 0
110#define hpet_set_rtc_irq_bit(arg) 0
111#define hpet_rtc_timer_init() do { } while (0)
112#define hpet_rtc_dropped_irq() 0
Bernhard Wallef8f76482008-01-30 13:33:31 +0100113#define hpet_register_irq_handler(h) 0
114#define hpet_unregister_irq_handler(h) 0
Andrew Morton533ffc22006-12-22 01:06:36 -0800115#ifdef RTC_IRQ
116static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
117{
118 return 0;
119}
120#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121#else
David Howells7d12e782006-10-05 14:55:46 +0100122extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
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
145static int rtc_ioctl(struct inode *inode, struct file *file,
146 unsigned int cmd, unsigned long arg);
147
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
David Howells7d12e782006-10-05 14:55:46 +0100238irqreturn_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)
521 BIN_TO_BCD(sec);
522 else
523 sec = 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100525 if (min < 60)
526 BIN_TO_BCD(min);
527 else
528 min = 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100530 if (hrs < 24)
531 BIN_TO_BCD(hrs);
532 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) {
617 BIN_TO_BCD(sec);
618 BIN_TO_BCD(min);
619 BIN_TO_BCD(hrs);
620 BIN_TO_BCD(day);
621 BIN_TO_BCD(mon);
622 BIN_TO_BCD(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;
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
Takashi Iwaic3348762005-11-07 11:14:57 +0100680 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 if (hpet_set_periodic_freq(arg)) {
Takashi Iwaic3348762005-11-07 11:14:57 +0100682 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 return 0;
684 }
685 rtc_freq = arg;
686
687 val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
688 val |= (16 - tmp);
689 CMOS_WRITE(val, RTC_FREQ_SELECT);
Takashi Iwaic3348762005-11-07 11:14:57 +0100690 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 return 0;
692 }
693#endif
694 case RTC_EPOCH_READ: /* Read the epoch. */
695 {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100696 return put_user(epoch, (unsigned long __user *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 }
698 case RTC_EPOCH_SET: /* Set the epoch. */
699 {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100700 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 * There were no RTC clocks before 1900.
702 */
703 if (arg < 1900)
704 return -EINVAL;
705
706 if (!capable(CAP_SYS_TIME))
707 return -EACCES;
708
709 epoch = arg;
710 return 0;
711 }
712 default:
713 return -ENOTTY;
714 }
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100715 return copy_to_user((void __user *)arg,
716 &wtime, sizeof wtime) ? -EFAULT : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717}
718
719static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
720 unsigned long arg)
721{
722 return rtc_do_ioctl(cmd, arg, 0);
723}
724
725/*
726 * We enforce only one user at a time here with the open/close.
727 * Also clear the previous interrupt data on an open, and clean
728 * up things on a close.
729 */
730
731/* We use rtc_lock to protect against concurrent opens. So the BKL is not
732 * needed here. Or anywhere else in this driver. */
733static int rtc_open(struct inode *inode, struct file *file)
734{
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100735 spin_lock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100737 if (rtc_status & RTC_IS_OPEN)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 goto out_busy;
739
740 rtc_status |= RTC_IS_OPEN;
741
742 rtc_irq_data = 0;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100743 spin_unlock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 return 0;
745
746out_busy:
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100747 spin_unlock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 return -EBUSY;
749}
750
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100751static int rtc_fasync(int fd, struct file *filp, int on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752{
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100753 return fasync_helper(fd, filp, on, &rtc_async_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754}
755
756static int rtc_release(struct inode *inode, struct file *file)
757{
758#ifdef RTC_IRQ
759 unsigned char tmp;
760
761 if (rtc_has_irq == 0)
762 goto no_irq;
763
764 /*
765 * Turn off all interrupts once the device is no longer
766 * in use, and clear the data.
767 */
768
769 spin_lock_irq(&rtc_lock);
770 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
771 tmp = CMOS_READ(RTC_CONTROL);
772 tmp &= ~RTC_PIE;
773 tmp &= ~RTC_AIE;
774 tmp &= ~RTC_UIE;
775 CMOS_WRITE(tmp, RTC_CONTROL);
776 CMOS_READ(RTC_INTR_FLAGS);
777 }
778 if (rtc_status & RTC_TIMER_ON) {
779 rtc_status &= ~RTC_TIMER_ON;
780 del_timer(&rtc_irq_timer);
781 }
782 spin_unlock_irq(&rtc_lock);
783
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100784 if (file->f_flags & FASYNC)
785 rtc_fasync(-1, file, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786no_irq:
787#endif
788
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100789 spin_lock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 rtc_irq_data = 0;
791 rtc_status &= ~RTC_IS_OPEN;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100792 spin_unlock_irq(&rtc_lock);
793
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 return 0;
795}
796
797#ifdef RTC_IRQ
798/* Called without the kernel lock - fine */
799static unsigned int rtc_poll(struct file *file, poll_table *wait)
800{
801 unsigned long l;
802
803 if (rtc_has_irq == 0)
804 return 0;
805
806 poll_wait(file, &rtc_wait, wait);
807
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100808 spin_lock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 l = rtc_irq_data;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100810 spin_unlock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811
812 if (l != 0)
813 return POLLIN | POLLRDNORM;
814 return 0;
815}
816#endif
817
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818int rtc_register(rtc_task_t *task)
819{
820#ifndef RTC_IRQ
821 return -EIO;
822#else
823 if (task == NULL || task->func == NULL)
824 return -EINVAL;
825 spin_lock_irq(&rtc_lock);
826 if (rtc_status & RTC_IS_OPEN) {
827 spin_unlock_irq(&rtc_lock);
828 return -EBUSY;
829 }
830 spin_lock(&rtc_task_lock);
831 if (rtc_callback) {
832 spin_unlock(&rtc_task_lock);
833 spin_unlock_irq(&rtc_lock);
834 return -EBUSY;
835 }
836 rtc_status |= RTC_IS_OPEN;
837 rtc_callback = task;
838 spin_unlock(&rtc_task_lock);
839 spin_unlock_irq(&rtc_lock);
840 return 0;
841#endif
842}
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100843EXPORT_SYMBOL(rtc_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844
845int rtc_unregister(rtc_task_t *task)
846{
847#ifndef RTC_IRQ
848 return -EIO;
849#else
850 unsigned char tmp;
851
852 spin_lock_irq(&rtc_lock);
853 spin_lock(&rtc_task_lock);
854 if (rtc_callback != task) {
855 spin_unlock(&rtc_task_lock);
856 spin_unlock_irq(&rtc_lock);
857 return -ENXIO;
858 }
859 rtc_callback = NULL;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100860
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 /* disable controls */
862 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
863 tmp = CMOS_READ(RTC_CONTROL);
864 tmp &= ~RTC_PIE;
865 tmp &= ~RTC_AIE;
866 tmp &= ~RTC_UIE;
867 CMOS_WRITE(tmp, RTC_CONTROL);
868 CMOS_READ(RTC_INTR_FLAGS);
869 }
870 if (rtc_status & RTC_TIMER_ON) {
871 rtc_status &= ~RTC_TIMER_ON;
872 del_timer(&rtc_irq_timer);
873 }
874 rtc_status &= ~RTC_IS_OPEN;
875 spin_unlock(&rtc_task_lock);
876 spin_unlock_irq(&rtc_lock);
877 return 0;
878#endif
879}
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100880EXPORT_SYMBOL(rtc_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881
882int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
883{
884#ifndef RTC_IRQ
885 return -EIO;
886#else
Takashi Iwaic3348762005-11-07 11:14:57 +0100887 unsigned long flags;
888 if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET)
889 return -EINVAL;
890 spin_lock_irqsave(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 if (rtc_callback != task) {
Takashi Iwaic3348762005-11-07 11:14:57 +0100892 spin_unlock_irqrestore(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 return -ENXIO;
894 }
Takashi Iwaic3348762005-11-07 11:14:57 +0100895 spin_unlock_irqrestore(&rtc_task_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 return rtc_do_ioctl(cmd, arg, 1);
897#endif
898}
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100899EXPORT_SYMBOL(rtc_control);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900
901/*
902 * The various file operations we support.
903 */
904
Arjan van de Ven62322d22006-07-03 00:24:21 -0700905static const struct file_operations rtc_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 .owner = THIS_MODULE,
907 .llseek = no_llseek,
908 .read = rtc_read,
909#ifdef RTC_IRQ
910 .poll = rtc_poll,
911#endif
912 .ioctl = rtc_ioctl,
913 .open = rtc_open,
914 .release = rtc_release,
915 .fasync = rtc_fasync,
916};
917
918static struct miscdevice rtc_dev = {
919 .minor = RTC_MINOR,
920 .name = "rtc",
921 .fops = &rtc_fops,
922};
923
Jan Beulich9cef7792006-12-13 00:35:05 -0800924#ifdef CONFIG_PROC_FS
Arjan van de Ven62322d22006-07-03 00:24:21 -0700925static const struct file_operations rtc_proc_fops = {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100926 .owner = THIS_MODULE,
927 .open = rtc_proc_open,
928 .read = seq_read,
929 .llseek = seq_lseek,
930 .release = single_release,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932#endif
933
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -0800934static resource_size_t rtc_size;
935
936static struct resource * __init rtc_request_region(resource_size_t size)
937{
938 struct resource *r;
939
940 if (RTC_IOMAPPED)
941 r = request_region(RTC_PORT(0), size, "rtc");
942 else
943 r = request_mem_region(RTC_PORT(0), size, "rtc");
944
945 if (r)
946 rtc_size = size;
947
948 return r;
949}
950
Bjorn Helgaas4c06be12007-11-14 16:59:56 -0800951static void rtc_release_region(void)
952{
953 if (RTC_IOMAPPED)
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -0800954 release_region(RTC_PORT(0), rtc_size);
Bjorn Helgaas4c06be12007-11-14 16:59:56 -0800955 else
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -0800956 release_mem_region(RTC_PORT(0), rtc_size);
Bjorn Helgaas4c06be12007-11-14 16:59:56 -0800957}
958
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959static int __init rtc_init(void)
960{
Jan Beulich9cef7792006-12-13 00:35:05 -0800961#ifdef CONFIG_PROC_FS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 struct proc_dir_entry *ent;
Jan Beulich9cef7792006-12-13 00:35:05 -0800963#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964#if defined(__alpha__) || defined(__mips__)
965 unsigned int year, ctrl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 char *guess = NULL;
967#endif
David S. Millercdee99d2007-07-19 13:59:58 -0700968#ifdef CONFIG_SPARC32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 struct linux_ebus *ebus;
970 struct linux_ebus_device *edev;
Jan Beulich9cef7792006-12-13 00:35:05 -0800971#else
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700972 void *r;
Jan Beulich9cef7792006-12-13 00:35:05 -0800973#ifdef RTC_IRQ
974 irq_handler_t rtc_int_handler_ptr;
975#endif
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -0700976#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977
David S. Millercdee99d2007-07-19 13:59:58 -0700978#ifdef CONFIG_SPARC32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 for_each_ebus(ebus) {
980 for_each_ebusdev(edev, ebus) {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +0100981 if (strcmp(edev->prom_node->name, "rtc") == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 rtc_port = edev->resource[0].start;
983 rtc_irq = edev->irqs[0];
984 goto found;
985 }
986 }
987 }
Jan Beulichf3e92d32006-12-13 00:35:04 -0800988 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 printk(KERN_ERR "rtc_init: no PC rtc found\n");
990 return -EIO;
991
992found:
993 if (rtc_irq == PCI_IRQ_NONE) {
994 rtc_has_irq = 0;
995 goto no_irq;
996 }
997
998 /*
999 * XXX Interrupt pin #7 in Espresso is shared between RTC and
David S. Miller53d0fc22005-09-05 23:33:05 -07001000 * PCI Slot 2 INTA# (and some INTx# in Slot 1).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001 */
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001002 if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc",
1003 (void *)&rtc_port)) {
Jan Beulichf3e92d32006-12-13 00:35:04 -08001004 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq);
1006 return -EIO;
1007 }
1008no_irq:
1009#else
Bjorn Helgaas9626f1f12007-11-14 16:59:57 -08001010 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);
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -07001021 if (!r) {
Jan Beulichf3e92d32006-12-13 00:35:04 -08001022#ifdef RTC_IRQ
1023 rtc_has_irq = 0;
1024#endif
Maciej W. Rozycki38e0e8c2006-07-10 04:45:30 -07001025 printk(KERN_ERR "rtc: I/O resource %lx is not free.\n",
1026 (long)(RTC_PORT(0)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 return -EIO;
1028 }
1029
1030#ifdef RTC_IRQ
1031 if (is_hpet_enabled()) {
Bernhard Wallef8f76482008-01-30 13:33:31 +01001032 int err;
1033
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 rtc_int_handler_ptr = hpet_rtc_interrupt;
Bernhard Wallef8f76482008-01-30 13:33:31 +01001035 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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 } else {
1042 rtc_int_handler_ptr = rtc_interrupt;
1043 }
1044
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001045 if (request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED,
1046 "rtc", NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 /* Yeah right, seeing as irq 8 doesn't even hit the bus. */
Jan Beulichf3e92d32006-12-13 00:35:04 -08001048 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
Bjorn Helgaas4c06be12007-11-14 16:59:56 -08001050 rtc_release_region();
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001051
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 return -EIO;
1053 }
1054 hpet_rtc_timer_init();
1055
1056#endif
1057
David S. Millercdee99d2007-07-19 13:59:58 -07001058#endif /* CONFIG_SPARC32 vs. others */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059
1060 if (misc_register(&rtc_dev)) {
1061#ifdef RTC_IRQ
1062 free_irq(RTC_IRQ, NULL);
Bernhard Wallef8f76482008-01-30 13:33:31 +01001063 hpet_unregister_irq_handler(rtc_interrupt);
Jan Beulichf3e92d32006-12-13 00:35:04 -08001064 rtc_has_irq = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065#endif
Bjorn Helgaas4c06be12007-11-14 16:59:56 -08001066 rtc_release_region();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 return -ENODEV;
1068 }
1069
Jan Beulich9cef7792006-12-13 00:35:05 -08001070#ifdef CONFIG_PROC_FS
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 ent = create_proc_entry("driver/rtc", 0, NULL);
Jan Beulich9cef7792006-12-13 00:35:05 -08001072 if (ent)
1073 ent->proc_fops = &rtc_proc_fops;
1074 else
1075 printk(KERN_WARNING "rtc: Failed to register with procfs.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077
1078#if defined(__alpha__) || defined(__mips__)
1079 rtc_freq = HZ;
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001080
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081 /* Each operating system on an Alpha uses its own epoch.
1082 Let's try to guess which one we are using now. */
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001083
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084 if (rtc_is_updating() != 0)
Luca Falavigna47f176f2005-06-28 20:44:42 -07001085 msleep(20);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001086
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087 spin_lock_irq(&rtc_lock);
1088 year = CMOS_READ(RTC_YEAR);
1089 ctrl = CMOS_READ(RTC_CONTROL);
1090 spin_unlock_irq(&rtc_lock);
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001091
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1093 BCD_TO_BIN(year); /* This should never happen... */
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001094
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 if (year < 20) {
1096 epoch = 2000;
1097 guess = "SRM (post-2000)";
1098 } else if (year >= 20 && year < 48) {
1099 epoch = 1980;
1100 guess = "ARC console";
1101 } else if (year >= 48 && year < 72) {
1102 epoch = 1952;
1103 guess = "Digital UNIX";
1104#if defined(__mips__)
1105 } else if (year >= 72 && year < 74) {
1106 epoch = 2000;
1107 guess = "Digital DECstation";
1108#else
1109 } else if (year >= 70) {
1110 epoch = 1900;
1111 guess = "Standard PC (1900)";
1112#endif
1113 }
1114 if (guess)
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001115 printk(KERN_INFO "rtc: %s epoch (%lu) detected\n",
1116 guess, epoch);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117#endif
1118#ifdef RTC_IRQ
1119 if (rtc_has_irq == 0)
1120 goto no_irq2;
1121
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 spin_lock_irq(&rtc_lock);
1123 rtc_freq = 1024;
1124 if (!hpet_set_periodic_freq(rtc_freq)) {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001125 /*
1126 * Initialize periodic frequency to CMOS reset default,
1127 * which is 1024Hz
1128 */
1129 CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06),
1130 RTC_FREQ_SELECT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131 }
1132 spin_unlock_irq(&rtc_lock);
1133no_irq2:
1134#endif
1135
1136 (void) init_sysctl();
1137
1138 printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
1139
1140 return 0;
1141}
1142
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001143static void __exit rtc_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144{
1145 cleanup_sysctl();
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001146 remove_proc_entry("driver/rtc", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147 misc_deregister(&rtc_dev);
1148
David S. Millercdee99d2007-07-19 13:59:58 -07001149#ifdef CONFIG_SPARC32
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150 if (rtc_has_irq)
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001151 free_irq(rtc_irq, &rtc_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152#else
Bjorn Helgaas4c06be12007-11-14 16:59:56 -08001153 rtc_release_region();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154#ifdef RTC_IRQ
Bernhard Wallef8f76482008-01-30 13:33:31 +01001155 if (rtc_has_irq) {
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001156 free_irq(RTC_IRQ, NULL);
Bernhard Wallef8f76482008-01-30 13:33:31 +01001157 hpet_unregister_irq_handler(hpet_rtc_interrupt);
1158 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159#endif
David S. Millercdee99d2007-07-19 13:59:58 -07001160#endif /* CONFIG_SPARC32 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161}
1162
1163module_init(rtc_init);
1164module_exit(rtc_exit);
1165
1166#ifdef RTC_IRQ
1167/*
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001168 * At IRQ rates >= 4096Hz, an interrupt may get lost altogether.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 * (usually during an IDE disk interrupt, with IRQ unmasking off)
1170 * Since the interrupt handler doesn't get called, the IRQ status
1171 * byte doesn't get read, and the RTC stops generating interrupts.
1172 * A timer is set, and will call this function if/when that happens.
1173 * To get it out of this stalled state, we just read the status.
1174 * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost.
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001175 * (You *really* shouldn't be trying to use a non-realtime system
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176 * for something that requires a steady > 1KHz signal anyways.)
1177 */
1178
1179static void rtc_dropped_irq(unsigned long data)
1180{
1181 unsigned long freq;
1182
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001183 spin_lock_irq(&rtc_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184
1185 if (hpet_rtc_dropped_irq()) {
1186 spin_unlock_irq(&rtc_lock);
1187 return;
1188 }
1189
1190 /* Just in case someone disabled the timer from behind our back... */
1191 if (rtc_status & RTC_TIMER_ON)
1192 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
1193
1194 rtc_irq_data += ((rtc_freq/HZ)<<8);
1195 rtc_irq_data &= ~0xff;
1196 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */
1197
1198 freq = rtc_freq;
1199
1200 spin_unlock_irq(&rtc_lock);
1201
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001202 if (printk_ratelimit()) {
1203 printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n",
1204 freq);
1205 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206
1207 /* Now we have new data */
1208 wake_up_interruptible(&rtc_wait);
1209
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001210 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211}
1212#endif
1213
Jan Beulich9cef7792006-12-13 00:35:05 -08001214#ifdef CONFIG_PROC_FS
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215/*
1216 * Info exported via "/proc/driver/rtc".
1217 */
1218
1219static int rtc_proc_show(struct seq_file *seq, void *v)
1220{
1221#define YN(bit) ((ctrl & bit) ? "yes" : "no")
1222#define NY(bit) ((ctrl & bit) ? "no" : "yes")
1223 struct rtc_time tm;
1224 unsigned char batt, ctrl;
1225 unsigned long freq;
1226
1227 spin_lock_irq(&rtc_lock);
1228 batt = CMOS_READ(RTC_VALID) & RTC_VRT;
1229 ctrl = CMOS_READ(RTC_CONTROL);
1230 freq = rtc_freq;
1231 spin_unlock_irq(&rtc_lock);
1232
1233
1234 rtc_get_rtc_time(&tm);
1235
1236 /*
1237 * There is no way to tell if the luser has the RTC set for local
1238 * time or for Universal Standard Time (GMT). Probably local though.
1239 */
1240 seq_printf(seq,
1241 "rtc_time\t: %02d:%02d:%02d\n"
1242 "rtc_date\t: %04d-%02d-%02d\n"
1243 "rtc_epoch\t: %04lu\n",
1244 tm.tm_hour, tm.tm_min, tm.tm_sec,
1245 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
1246
1247 get_rtc_alm_time(&tm);
1248
1249 /*
1250 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
1251 * match any value for that particular field. Values that are
1252 * greater than a valid time, but less than 0xc0 shouldn't appear.
1253 */
1254 seq_puts(seq, "alarm\t\t: ");
1255 if (tm.tm_hour <= 24)
1256 seq_printf(seq, "%02d:", tm.tm_hour);
1257 else
1258 seq_puts(seq, "**:");
1259
1260 if (tm.tm_min <= 59)
1261 seq_printf(seq, "%02d:", tm.tm_min);
1262 else
1263 seq_puts(seq, "**:");
1264
1265 if (tm.tm_sec <= 59)
1266 seq_printf(seq, "%02d\n", tm.tm_sec);
1267 else
1268 seq_puts(seq, "**\n");
1269
1270 seq_printf(seq,
1271 "DST_enable\t: %s\n"
1272 "BCD\t\t: %s\n"
1273 "24hr\t\t: %s\n"
1274 "square_wave\t: %s\n"
1275 "alarm_IRQ\t: %s\n"
1276 "update_IRQ\t: %s\n"
1277 "periodic_IRQ\t: %s\n"
1278 "periodic_freq\t: %ld\n"
1279 "batt_status\t: %s\n",
1280 YN(RTC_DST_EN),
1281 NY(RTC_DM_BINARY),
1282 YN(RTC_24H),
1283 YN(RTC_SQWE),
1284 YN(RTC_AIE),
1285 YN(RTC_UIE),
1286 YN(RTC_PIE),
1287 freq,
1288 batt ? "okay" : "dead");
1289
1290 return 0;
1291#undef YN
1292#undef NY
1293}
1294
1295static int rtc_proc_open(struct inode *inode, struct file *file)
1296{
1297 return single_open(file, rtc_proc_show, NULL);
1298}
Jan Beulich9cef7792006-12-13 00:35:05 -08001299#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300
1301void rtc_get_rtc_time(struct rtc_time *rtc_tm)
1302{
Ingo Molnar0f749642006-07-12 09:03:10 -07001303 unsigned long uip_watchdog = jiffies, flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304 unsigned char ctrl;
1305#ifdef CONFIG_MACH_DECSTATION
1306 unsigned int real_year;
1307#endif
1308
1309 /*
1310 * read RTC once any update in progress is done. The update
Luca Falavigna47f176f2005-06-28 20:44:42 -07001311 * can take just over 2ms. We wait 20ms. There is no need to
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
1313 * If you need to know *exactly* when a second has started, enable
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001314 * periodic update complete interrupts, (via ioctl) and then
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 * immediately read /dev/rtc which will block until you get the IRQ.
1316 * Once the read clears, read the RTC time (again via ioctl). Easy.
1317 */
1318
Steven Rostedt358333a2006-09-29 01:59:04 -07001319 while (rtc_is_updating() != 0 && jiffies - uip_watchdog < 2*HZ/100)
Petr Vandrovec403fe5a2005-08-05 15:50:07 +02001320 cpu_relax();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321
1322 /*
1323 * Only the values that we read from the RTC are set. We leave
Alan Coxb7599582006-01-11 12:17:32 -08001324 * tm_wday, tm_yday and tm_isdst untouched. Note that while the
1325 * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is
1326 * only updated by the RTC when initially set to a non-zero value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 */
Ingo Molnar0f749642006-07-12 09:03:10 -07001328 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
1330 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
1331 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
1332 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
1333 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
1334 rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
Alan Coxb7599582006-01-11 12:17:32 -08001335 /* Only set from 2.6.16 onwards */
1336 rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK);
1337
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338#ifdef CONFIG_MACH_DECSTATION
1339 real_year = CMOS_READ(RTC_DEC_YEAR);
1340#endif
1341 ctrl = CMOS_READ(RTC_CONTROL);
Ingo Molnar0f749642006-07-12 09:03:10 -07001342 spin_unlock_irqrestore(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001343
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001344 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 BCD_TO_BIN(rtc_tm->tm_sec);
1346 BCD_TO_BIN(rtc_tm->tm_min);
1347 BCD_TO_BIN(rtc_tm->tm_hour);
1348 BCD_TO_BIN(rtc_tm->tm_mday);
1349 BCD_TO_BIN(rtc_tm->tm_mon);
1350 BCD_TO_BIN(rtc_tm->tm_year);
Alan Coxb7599582006-01-11 12:17:32 -08001351 BCD_TO_BIN(rtc_tm->tm_wday);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 }
1353
1354#ifdef CONFIG_MACH_DECSTATION
1355 rtc_tm->tm_year += real_year - 72;
1356#endif
1357
1358 /*
1359 * Account for differences between how the RTC uses the values
1360 * and how they are defined in a struct rtc_time;
1361 */
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001362 rtc_tm->tm_year += epoch - 1900;
1363 if (rtc_tm->tm_year <= 69)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001364 rtc_tm->tm_year += 100;
1365
1366 rtc_tm->tm_mon--;
1367}
1368
1369static void get_rtc_alm_time(struct rtc_time *alm_tm)
1370{
1371 unsigned char ctrl;
1372
1373 /*
1374 * Only the values that we read from the RTC are set. That
1375 * means only tm_hour, tm_min, and tm_sec.
1376 */
1377 spin_lock_irq(&rtc_lock);
1378 alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
1379 alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM);
1380 alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM);
1381 ctrl = CMOS_READ(RTC_CONTROL);
1382 spin_unlock_irq(&rtc_lock);
1383
Ingo Molnar5fd1fe92008-01-30 13:31:09 +01001384 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385 BCD_TO_BIN(alm_tm->tm_sec);
1386 BCD_TO_BIN(alm_tm->tm_min);
1387 BCD_TO_BIN(alm_tm->tm_hour);
1388 }
1389}
1390
1391#ifdef RTC_IRQ
1392/*
1393 * Used to disable/enable interrupts for any one of UIE, AIE, PIE.
1394 * Rumour has it that if you frob the interrupt enable/disable
1395 * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to
1396 * ensure you actually start getting interrupts. Probably for
1397 * compatibility with older/broken chipset RTC implementations.
1398 * We also clear out any old irq data after an ioctl() that
1399 * meddles with the interrupt enable/disable bits.
1400 */
1401
Takashi Iwaic3348762005-11-07 11:14:57 +01001402static void mask_rtc_irq_bit_locked(unsigned char bit)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001403{
1404 unsigned char val;
1405
Takashi Iwaic3348762005-11-07 11:14:57 +01001406 if (hpet_mask_rtc_irq_bit(bit))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408 val = CMOS_READ(RTC_CONTROL);
1409 val &= ~bit;
1410 CMOS_WRITE(val, RTC_CONTROL);
1411 CMOS_READ(RTC_INTR_FLAGS);
1412
1413 rtc_irq_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001414}
1415
Takashi Iwaic3348762005-11-07 11:14:57 +01001416static void set_rtc_irq_bit_locked(unsigned char bit)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417{
1418 unsigned char val;
1419
Takashi Iwaic3348762005-11-07 11:14:57 +01001420 if (hpet_set_rtc_irq_bit(bit))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001422 val = CMOS_READ(RTC_CONTROL);
1423 val |= bit;
1424 CMOS_WRITE(val, RTC_CONTROL);
1425 CMOS_READ(RTC_INTR_FLAGS);
1426
1427 rtc_irq_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428}
1429#endif
1430
1431MODULE_AUTHOR("Paul Gortmaker");
1432MODULE_LICENSE("GPL");
1433MODULE_ALIAS_MISCDEV(RTC_MINOR);