Kernel

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Root/drivers/char/rtc.c

1	/*
2	* Real Time Clock interface for Linux
3	*
4	* Copyright (C) 1996 Paul Gortmaker
5	*
6	* This driver allows use of the real time clock (built into
7	* nearly all computers) from user space. It exports the /dev/rtc
8	* interface supporting various ioctl() and also the
9	* /proc/driver/rtc pseudo-file for status information.
10	*
11	* The ioctls can be used to set the interrupt behaviour and
12	* generation rate from the RTC via IRQ 8. Then the /dev/rtc
13	* interface can be used to make use of these timer interrupts,
14	* be they interval or alarm based.
15	*
16	* The /dev/rtc interface will block on reads until an interrupt
17	* has been received. If a RTC interrupt has already happened,
18	* it will output an unsigned long and then block. The output value
19	* contains the interrupt status in the low byte and the number of
20	* interrupts since the last read in the remaining high bytes. The
21	* /dev/rtc interface can also be used with the select(2) call.
22	*
23	* This program is free software; you can redistribute it and/or
24	* modify it under the terms of the GNU General Public License
25	* as published by the Free Software Foundation; either version
26	* 2 of the License, or (at your option) any later version.
27	*
28	* Based on other minimal char device drivers, like Alan's
29	* watchdog, Ted's random, etc. etc.
30	*
31	* 1.07 Paul Gortmaker.
32	* 1.08 Miquel van Smoorenburg: disallow certain things on the
33	* DEC Alpha as the CMOS clock is also used for other things.
34	* 1.09 Nikita Schmidt: epoch support and some Alpha cleanup.
35	* 1.09a Pete Zaitcev: Sun SPARC
36	* 1.09b Jeff Garzik: Modularize, init cleanup
37	* 1.09c Jeff Garzik: SMP cleanup
38	* 1.10 Paul Barton-Davis: add support for async I/O
39	* 1.10a Andrea Arcangeli: Alpha updates
40	* 1.10b Andrew Morton: SMP lock fix
41	* 1.10c Cesar Barros: SMP locking fixes and cleanup
42	* 1.10d Paul Gortmaker: delete paranoia check in rtc_exit
43	* 1.10e Maciej W. Rozycki: Handle DECstation's year weirdness.
44	* 1.11 Takashi Iwai: Kernel access functions
45	* rtc_register/rtc_unregister/rtc_control
46	* 1.11a Daniele Bellucci: Audit create_proc_read_entry in rtc_init
47	* 1.12 Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
48	* CONFIG_HPET_EMULATE_RTC
49	* 1.12a Maciej W. Rozycki: Handle memory-mapped chips properly.
50	* 1.12ac Alan Cox: Allow read access to the day of week register
51	* 1.12b David John: Remove calls to the BKL.
52	*/
53
54	#define RTC_VERSION "1.12b"
55
56	/*
57	* Note that all calls to CMOS_READ and CMOS_WRITE are done with
58	* interrupts disabled. Due to the index-port/data-port (0x70/0x71)
59	* design of the RTC, we don't want two different things trying to
60	* get to it at once. (e.g. the periodic 11 min sync from
61	* kernel/time/ntp.c vs. this driver.)
62	*/
63
64	#include <linux/interrupt.h>
65	#include <linux/module.h>
66	#include <linux/kernel.h>
67	#include <linux/types.h>
68	#include <linux/miscdevice.h>
69	#include <linux/ioport.h>
70	#include <linux/fcntl.h>
71	#include <linux/mc146818rtc.h>
72	#include <linux/init.h>
73	#include <linux/poll.h>
74	#include <linux/proc_fs.h>
75	#include <linux/seq_file.h>
76	#include <linux/spinlock.h>
77	#include <linux/sched.h>
78	#include <linux/sysctl.h>
79	#include <linux/wait.h>
80	#include <linux/bcd.h>
81	#include <linux/delay.h>
82	#include <linux/uaccess.h>
83	#include <linux/ratelimit.h>
84
85	#include <asm/current.h>
86
87	#ifdef CONFIG_X86
88	#include <asm/hpet.h>
89	#endif
90
91	#ifdef CONFIG_SPARC32
92	#include <linux/of.h>
93	#include <linux/of_device.h>
94	#include <asm/io.h>
95
96	static unsigned long rtc_port;
97	static int rtc_irq;
98	#endif
99
100	#ifdef CONFIG_HPET_EMULATE_RTC
101	#undef RTC_IRQ
102	#endif
103
104	#ifdef RTC_IRQ
105	static int rtc_has_irq = 1;
106	#endif
107
108	#ifndef CONFIG_HPET_EMULATE_RTC
109	#define is_hpet_enabled() 0
110	#define hpet_set_alarm_time(hrs, min, sec) 0
111	#define hpet_set_periodic_freq(arg) 0
112	#define hpet_mask_rtc_irq_bit(arg) 0
113	#define hpet_set_rtc_irq_bit(arg) 0
114	#define hpet_rtc_timer_init() do { } while (0)
115	#define hpet_rtc_dropped_irq() 0
116	#define hpet_register_irq_handler(h) ({ 0; })
117	#define hpet_unregister_irq_handler(h) ({ 0; })
118	#ifdef RTC_IRQ
119	static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
120	{
121	return 0;
122	}
123	#endif
124	#endif
125
126	/*
127	* We sponge a minor off of the misc major. No need slurping
128	* up another valuable major dev number for this. If you add
129	* an ioctl, make sure you don't conflict with SPARC's RTC
130	* ioctls.
131	*/
132
133	static struct fasync_struct *rtc_async_queue;
134
135	static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
136
137	#ifdef RTC_IRQ
138	static void rtc_dropped_irq(unsigned long data);
139
140	static DEFINE_TIMER(rtc_irq_timer, rtc_dropped_irq, 0, 0);
141	#endif
142
143	static ssize_t rtc_read(struct file file, char __user buf,
144	size_t count, loff_t *ppos);
145
146	static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
147	static void rtc_get_rtc_time(struct rtc_time *rtc_tm);
148
149	#ifdef RTC_IRQ
150	static unsigned int rtc_poll(struct file file, poll_table wait);
151	#endif
152
153	static void get_rtc_alm_time(struct rtc_time *alm_tm);
154	#ifdef RTC_IRQ
155	static void set_rtc_irq_bit_locked(unsigned char bit);
156	static void mask_rtc_irq_bit_locked(unsigned char bit);
157
158	static inline void set_rtc_irq_bit(unsigned char bit)
159	{
160	spin_lock_irq(&rtc_lock);
161	set_rtc_irq_bit_locked(bit);
162	spin_unlock_irq(&rtc_lock);
163	}
164
165	static void mask_rtc_irq_bit(unsigned char bit)
166	{
167	spin_lock_irq(&rtc_lock);
168	mask_rtc_irq_bit_locked(bit);
169	spin_unlock_irq(&rtc_lock);
170	}
171	#endif
172
173	#ifdef CONFIG_PROC_FS
174	static int rtc_proc_open(struct inode inode, struct file file);
175	#endif
176
177	/*
178	* Bits in rtc_status. (6 bits of room for future expansion)
179	*/
180
181	#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
182	#define RTC_TIMER_ON 0x02 /* missed irq timer active */
183
184	/*
185	* rtc_status is never changed by rtc_interrupt, and ioctl/open/close is
186	* protected by the spin lock rtc_lock. However, ioctl can still disable the
187	* timer in rtc_status and then with del_timer after the interrupt has read
188	* rtc_status but before mod_timer is called, which would then reenable the
189	* timer (but you would need to have an awful timing before you'd trip on it)
190	*/
191	static unsigned long rtc_status; /* bitmapped status byte. */
192	static unsigned long rtc_freq; /* Current periodic IRQ rate */
193	static unsigned long rtc_irq_data; /* our output to the world */
194	static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */
195
196	#ifdef RTC_IRQ
197	/*
198	* rtc_task_lock nests inside rtc_lock.
199	*/
200	static DEFINE_SPINLOCK(rtc_task_lock);
201	static rtc_task_t *rtc_callback;
202	#endif
203
204	/*
205	* If this driver ever becomes modularised, it will be really nice
206	* to make the epoch retain its value across module reload...
207	*/
208
209	static unsigned long epoch = 1900; /* year corresponding to 0x00 */
210
211	static const unsigned char days_in_mo[] =
212	{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
213
214	/*
215	* Returns true if a clock update is in progress
216	*/
217	static inline unsigned char rtc_is_updating(void)
218	{
219	unsigned long flags;
220	unsigned char uip;
221
222	spin_lock_irqsave(&rtc_lock, flags);
223	uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
224	spin_unlock_irqrestore(&rtc_lock, flags);
225	return uip;
226	}
227
228	#ifdef RTC_IRQ
229	/*
230	* A very tiny interrupt handler. It runs with IRQF_DISABLED set,
231	* but there is possibility of conflicting with the set_rtc_mmss()
232	* call (the rtc irq and the timer irq can easily run at the same
233	* time in two different CPUs). So we need to serialize
234	* accesses to the chip with the rtc_lock spinlock that each
235	* architecture should implement in the timer code.
236	* (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.)
237	*/
238
239	static irqreturn_t rtc_interrupt(int irq, void *dev_id)
240	{
241	/*
242	* Can be an alarm interrupt, update complete interrupt,
243	* or a periodic interrupt. We store the status in the
244	* low byte and the number of interrupts received since
245	* the last read in the remainder of rtc_irq_data.
246	*/
247
248	spin_lock(&rtc_lock);
249	rtc_irq_data += 0x100;
250	rtc_irq_data &= ~0xff;
251	if (is_hpet_enabled()) {
252	/*
253	* In this case it is HPET RTC interrupt handler
254	* calling us, with the interrupt information
255	* passed as arg1, instead of irq.
256	*/
257	rtc_irq_data \|= (unsigned long)irq & 0xF0;
258	} else {
259	rtc_irq_data \|= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0);
260	}
261
262	if (rtc_status & RTC_TIMER_ON)
263	mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
264
265	spin_unlock(&rtc_lock);
266
267	/* Now do the rest of the actions */
268	spin_lock(&rtc_task_lock);
269	if (rtc_callback)
270	rtc_callback->func(rtc_callback->private_data);
271	spin_unlock(&rtc_task_lock);
272	wake_up_interruptible(&rtc_wait);
273
274	kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
275
276	return IRQ_HANDLED;
277	}
278	#endif
279
280	/*
281	* sysctl-tuning infrastructure.
282	*/
283	static ctl_table rtc_table[] = {
284	{
285	.procname = "max-user-freq",
286	.data = &rtc_max_user_freq,
287	.maxlen = sizeof(int),
288	.mode = 0644,
289	.proc_handler = proc_dointvec,
290	},
291	{ }
292	};
293
294	static ctl_table rtc_root[] = {
295	{
296	.procname = "rtc",
297	.mode = 0555,
298	.child = rtc_table,
299	},
300	{ }
301	};
302
303	static ctl_table dev_root[] = {
304	{
305	.procname = "dev",
306	.mode = 0555,
307	.child = rtc_root,
308	},
309	{ }
310	};
311
312	static struct ctl_table_header *sysctl_header;
313
314	static int __init init_sysctl(void)
315	{
316	sysctl_header = register_sysctl_table(dev_root);
317	return 0;
318	}
319
320	static void __exit cleanup_sysctl(void)
321	{
322	unregister_sysctl_table(sysctl_header);
323	}
324
325	/*
326	* Now all the various file operations that we export.
327	*/
328
329	static ssize_t rtc_read(struct file file, char __user buf,
330	size_t count, loff_t *ppos)
331	{
332	#ifndef RTC_IRQ
333	return -EIO;
334	#else
335	DECLARE_WAITQUEUE(wait, current);
336	unsigned long data;
337	ssize_t retval;
338
339	if (rtc_has_irq == 0)
340	return -EIO;
341
342	/*
343	* Historically this function used to assume that sizeof(unsigned long)
344	* is the same in userspace and kernelspace. This lead to problems
345	* for configurations with multiple ABIs such a the MIPS o32 and 64
346	* ABIs supported on the same kernel. So now we support read of both
347	* 4 and 8 bytes and assume that's the sizeof(unsigned long) in the
348	* userspace ABI.
349	*/
350	if (count != sizeof(unsigned int) && count != sizeof(unsigned long))
351	return -EINVAL;
352
353	add_wait_queue(&rtc_wait, &wait);
354
355	do {
356	/* First make it right. Then make it fast. Putting this whole
357	* block within the parentheses of a while would be too
358	* confusing. And no, xchg() is not the answer. */
359
360	__set_current_state(TASK_INTERRUPTIBLE);
361
362	spin_lock_irq(&rtc_lock);
363	data = rtc_irq_data;
364	rtc_irq_data = 0;
365	spin_unlock_irq(&rtc_lock);
366
367	if (data != 0)
368	break;
369
370	if (file->f_flags & O_NONBLOCK) {
371	retval = -EAGAIN;
372	goto out;
373	}
374	if (signal_pending(current)) {
375	retval = -ERESTARTSYS;
376	goto out;
377	}
378	schedule();
379	} while (1);
380
381	if (count == sizeof(unsigned int)) {
382	retval = put_user(data,
383	(unsigned int __user *)buf) ?: sizeof(int);
384	} else {
385	retval = put_user(data,
386	(unsigned long __user *)buf) ?: sizeof(long);
387	}
388	if (!retval)
389	retval = count;
390	out:
391	__set_current_state(TASK_RUNNING);
392	remove_wait_queue(&rtc_wait, &wait);
393
394	return retval;
395	#endif
396	}
397
398	static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
399	{
400	struct rtc_time wtime;
401
402	#ifdef RTC_IRQ
403	if (rtc_has_irq == 0) {
404	switch (cmd) {
405	case RTC_AIE_OFF:
406	case RTC_AIE_ON:
407	case RTC_PIE_OFF:
408	case RTC_PIE_ON:
409	case RTC_UIE_OFF:
410	case RTC_UIE_ON:
411	case RTC_IRQP_READ:
412	case RTC_IRQP_SET:
413	return -EINVAL;
414	}
415	}
416	#endif
417
418	switch (cmd) {
419	#ifdef RTC_IRQ
420	case RTC_AIE_OFF: /* Mask alarm int. enab. bit */
421	{
422	mask_rtc_irq_bit(RTC_AIE);
423	return 0;
424	}
425	case RTC_AIE_ON: /* Allow alarm interrupts. */
426	{
427	set_rtc_irq_bit(RTC_AIE);
428	return 0;
429	}
430	case RTC_PIE_OFF: /* Mask periodic int. enab. bit */
431	{
432	/* can be called from isr via rtc_control() */
433	unsigned long flags;
434
435	spin_lock_irqsave(&rtc_lock, flags);
436	mask_rtc_irq_bit_locked(RTC_PIE);
437	if (rtc_status & RTC_TIMER_ON) {
438	rtc_status &= ~RTC_TIMER_ON;
439	del_timer(&rtc_irq_timer);
440	}
441	spin_unlock_irqrestore(&rtc_lock, flags);
442
443	return 0;
444	}
445	case RTC_PIE_ON: /* Allow periodic ints */
446	{
447	/* can be called from isr via rtc_control() */
448	unsigned long flags;
449
450	/*
451	* We don't really want Joe User enabling more
452	* than 64Hz of interrupts on a multi-user machine.
453	*/
454	if (!kernel && (rtc_freq > rtc_max_user_freq) &&
455	(!capable(CAP_SYS_RESOURCE)))
456	return -EACCES;
457
458	spin_lock_irqsave(&rtc_lock, flags);
459	if (!(rtc_status & RTC_TIMER_ON)) {
460	mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq +
461	2*HZ/100);
462	rtc_status \|= RTC_TIMER_ON;
463	}
464	set_rtc_irq_bit_locked(RTC_PIE);
465	spin_unlock_irqrestore(&rtc_lock, flags);
466
467	return 0;
468	}
469	case RTC_UIE_OFF: /* Mask ints from RTC updates. */
470	{
471	mask_rtc_irq_bit(RTC_UIE);
472	return 0;
473	}
474	case RTC_UIE_ON: /* Allow ints for RTC updates. */
475	{
476	set_rtc_irq_bit(RTC_UIE);
477	return 0;
478	}
479	#endif
480	case RTC_ALM_READ: /* Read the present alarm time */
481	{
482	/*
483	* This returns a struct rtc_time. Reading >= 0xc0
484	* means "don't care" or "match all". Only the tm_hour,
485	* tm_min, and tm_sec values are filled in.
486	*/
487	memset(&wtime, 0, sizeof(struct rtc_time));
488	get_rtc_alm_time(&wtime);
489	break;
490	}
491	case RTC_ALM_SET: /* Store a time into the alarm */
492	{
493	/*
494	* This expects a struct rtc_time. Writing 0xff means
495	* "don't care" or "match all". Only the tm_hour,
496	* tm_min and tm_sec are used.
497	*/
498	unsigned char hrs, min, sec;
499	struct rtc_time alm_tm;
500
501	if (copy_from_user(&alm_tm, (struct rtc_time __user *)arg,
502	sizeof(struct rtc_time)))
503	return -EFAULT;
504
505	hrs = alm_tm.tm_hour;
506	min = alm_tm.tm_min;
507	sec = alm_tm.tm_sec;
508
509	spin_lock_irq(&rtc_lock);
510	if (hpet_set_alarm_time(hrs, min, sec)) {
511	/*
512	* Fallthru and set alarm time in CMOS too,
513	* so that we will get proper value in RTC_ALM_READ
514	*/
515	}
516	if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) \|\|
517	RTC_ALWAYS_BCD) {
518	if (sec < 60)
519	sec = bin2bcd(sec);
520	else
521	sec = 0xff;
522
523	if (min < 60)
524	min = bin2bcd(min);
525	else
526	min = 0xff;
527
528	if (hrs < 24)
529	hrs = bin2bcd(hrs);
530	else
531	hrs = 0xff;
532	}
533	CMOS_WRITE(hrs, RTC_HOURS_ALARM);
534	CMOS_WRITE(min, RTC_MINUTES_ALARM);
535	CMOS_WRITE(sec, RTC_SECONDS_ALARM);
536	spin_unlock_irq(&rtc_lock);
537
538	return 0;
539	}
540	case RTC_RD_TIME: /* Read the time/date from RTC */
541	{
542	memset(&wtime, 0, sizeof(struct rtc_time));
543	rtc_get_rtc_time(&wtime);
544	break;
545	}
546	case RTC_SET_TIME: /* Set the RTC */
547	{
548	struct rtc_time rtc_tm;
549	unsigned char mon, day, hrs, min, sec, leap_yr;
550	unsigned char save_control, save_freq_select;
551	unsigned int yrs;
552	#ifdef CONFIG_MACH_DECSTATION
553	unsigned int real_yrs;
554	#endif
555
556	if (!capable(CAP_SYS_TIME))
557	return -EACCES;
558
559	if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg,
560	sizeof(struct rtc_time)))
561	return -EFAULT;
562
563	yrs = rtc_tm.tm_year + 1900;
564	mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
565	day = rtc_tm.tm_mday;
566	hrs = rtc_tm.tm_hour;
567	min = rtc_tm.tm_min;
568	sec = rtc_tm.tm_sec;
569
570	if (yrs < 1970)
571	return -EINVAL;
572
573	leap_yr = ((!(yrs % 4) && (yrs % 100)) \|\| !(yrs % 400));
574
575	if ((mon > 12) \|\| (day == 0))
576	return -EINVAL;
577
578	if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
579	return -EINVAL;
580
581	if ((hrs >= 24) \|\| (min >= 60) \|\| (sec >= 60))
582	return -EINVAL;
583
584	yrs -= epoch;
585	if (yrs > 255) /* They are unsigned */
586	return -EINVAL;
587
588	spin_lock_irq(&rtc_lock);
589	#ifdef CONFIG_MACH_DECSTATION
590	real_yrs = yrs;
591	yrs = 72;
592
593	/*
594	* We want to keep the year set to 73 until March
595	* for non-leap years, so that Feb, 29th is handled
596	* correctly.
597	*/
598	if (!leap_yr && mon < 3) {
599	real_yrs--;
600	yrs = 73;
601	}
602	#endif
603	/* These limits and adjustments are independent of
604	* whether the chip is in binary mode or not.
605	*/
606	if (yrs > 169) {
607	spin_unlock_irq(&rtc_lock);
608	return -EINVAL;
609	}
610	if (yrs >= 100)
611	yrs -= 100;
612
613	if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
614	\|\| RTC_ALWAYS_BCD) {
615	sec = bin2bcd(sec);
616	min = bin2bcd(min);
617	hrs = bin2bcd(hrs);
618	day = bin2bcd(day);
619	mon = bin2bcd(mon);
620	yrs = bin2bcd(yrs);
621	}
622
623	save_control = CMOS_READ(RTC_CONTROL);
624	CMOS_WRITE((save_control\|RTC_SET), RTC_CONTROL);
625	save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
626	CMOS_WRITE((save_freq_select\|RTC_DIV_RESET2), RTC_FREQ_SELECT);
627
628	#ifdef CONFIG_MACH_DECSTATION
629	CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
630	#endif
631	CMOS_WRITE(yrs, RTC_YEAR);
632	CMOS_WRITE(mon, RTC_MONTH);
633	CMOS_WRITE(day, RTC_DAY_OF_MONTH);
634	CMOS_WRITE(hrs, RTC_HOURS);
635	CMOS_WRITE(min, RTC_MINUTES);
636	CMOS_WRITE(sec, RTC_SECONDS);
637
638	CMOS_WRITE(save_control, RTC_CONTROL);
639	CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
640
641	spin_unlock_irq(&rtc_lock);
642	return 0;
643	}
644	#ifdef RTC_IRQ
645	case RTC_IRQP_READ: /* Read the periodic IRQ rate. */
646	{
647	return put_user(rtc_freq, (unsigned long __user *)arg);
648	}
649	case RTC_IRQP_SET: /* Set periodic IRQ rate. */
650	{
651	int tmp = 0;
652	unsigned char val;
653	/* can be called from isr via rtc_control() */
654	unsigned long flags;
655
656	/*
657	* The max we can do is 8192Hz.
658	*/
659	if ((arg < 2) \|\| (arg > 8192))
660	return -EINVAL;
661	/*
662	* We don't really want Joe User generating more
663	* than 64Hz of interrupts on a multi-user machine.
664	*/
665	if (!kernel && (arg > rtc_max_user_freq) &&
666	!capable(CAP_SYS_RESOURCE))
667	return -EACCES;
668
669	while (arg > (1<<tmp))
670	tmp++;
671
672	/*
673	* Check that the input was really a power of 2.
674	*/
675	if (arg != (1<<tmp))
676	return -EINVAL;
677
678	rtc_freq = arg;
679
680	spin_lock_irqsave(&rtc_lock, flags);
681	if (hpet_set_periodic_freq(arg)) {
682	spin_unlock_irqrestore(&rtc_lock, flags);
683	return 0;
684	}
685
686	val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
687	val \|= (16 - tmp);
688	CMOS_WRITE(val, RTC_FREQ_SELECT);
689	spin_unlock_irqrestore(&rtc_lock, flags);
690	return 0;
691	}
692	#endif
693	case RTC_EPOCH_READ: /* Read the epoch. */
694	{
695	return put_user(epoch, (unsigned long __user *)arg);
696	}
697	case RTC_EPOCH_SET: /* Set the epoch. */
698	{
699	/*
700	* There were no RTC clocks before 1900.
701	*/
702	if (arg < 1900)
703	return -EINVAL;
704
705	if (!capable(CAP_SYS_TIME))
706	return -EACCES;
707
708	epoch = arg;
709	return 0;
710	}
711	default:
712	return -ENOTTY;
713	}
714	return copy_to_user((void __user *)arg,
715	&wtime, sizeof wtime) ? -EFAULT : 0;
716	}
717
718	static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
719	{
720	long ret;
721	ret = rtc_do_ioctl(cmd, arg, 0);
722	return ret;
723	}
724
725	/*
726	* We enforce only one user at a time here with the open/close.
727	* Also clear the previous interrupt data on an open, and clean
728	* up things on a close.
729	*/
730	static int rtc_open(struct inode inode, struct file file)
731	{
732	spin_lock_irq(&rtc_lock);
733
734	if (rtc_status & RTC_IS_OPEN)
735	goto out_busy;
736
737	rtc_status \|= RTC_IS_OPEN;
738
739	rtc_irq_data = 0;
740	spin_unlock_irq(&rtc_lock);
741	return 0;
742
743	out_busy:
744	spin_unlock_irq(&rtc_lock);
745	return -EBUSY;
746	}
747
748	static int rtc_fasync(int fd, struct file *filp, int on)
749	{
750	return fasync_helper(fd, filp, on, &rtc_async_queue);
751	}
752
753	static int rtc_release(struct inode inode, struct file file)
754	{
755	#ifdef RTC_IRQ
756	unsigned char tmp;
757
758	if (rtc_has_irq == 0)
759	goto no_irq;
760
761	/*
762	* Turn off all interrupts once the device is no longer
763	* in use, and clear the data.
764	*/
765
766	spin_lock_irq(&rtc_lock);
767	if (!hpet_mask_rtc_irq_bit(RTC_PIE \| RTC_AIE \| RTC_UIE)) {
768	tmp = CMOS_READ(RTC_CONTROL);
769	tmp &= ~RTC_PIE;
770	tmp &= ~RTC_AIE;
771	tmp &= ~RTC_UIE;
772	CMOS_WRITE(tmp, RTC_CONTROL);
773	CMOS_READ(RTC_INTR_FLAGS);
774	}
775	if (rtc_status & RTC_TIMER_ON) {
776	rtc_status &= ~RTC_TIMER_ON;
777	del_timer(&rtc_irq_timer);
778	}
779	spin_unlock_irq(&rtc_lock);
780
781	no_irq:
782	#endif
783
784	spin_lock_irq(&rtc_lock);
785	rtc_irq_data = 0;
786	rtc_status &= ~RTC_IS_OPEN;
787	spin_unlock_irq(&rtc_lock);
788
789	return 0;
790	}
791
792	#ifdef RTC_IRQ
793	static unsigned int rtc_poll(struct file file, poll_table wait)
794	{
795	unsigned long l;
796
797	if (rtc_has_irq == 0)
798	return 0;
799
800	poll_wait(file, &rtc_wait, wait);
801
802	spin_lock_irq(&rtc_lock);
803	l = rtc_irq_data;
804	spin_unlock_irq(&rtc_lock);
805
806	if (l != 0)
807	return POLLIN \| POLLRDNORM;
808	return 0;
809	}
810	#endif
811
812	int rtc_register(rtc_task_t *task)
813	{
814	#ifndef RTC_IRQ
815	return -EIO;
816	#else
817	if (task == NULL \|\| task->func == NULL)
818	return -EINVAL;
819	spin_lock_irq(&rtc_lock);
820	if (rtc_status & RTC_IS_OPEN) {
821	spin_unlock_irq(&rtc_lock);
822	return -EBUSY;
823	}
824	spin_lock(&rtc_task_lock);
825	if (rtc_callback) {
826	spin_unlock(&rtc_task_lock);
827	spin_unlock_irq(&rtc_lock);
828	return -EBUSY;
829	}
830	rtc_status \|= RTC_IS_OPEN;
831	rtc_callback = task;
832	spin_unlock(&rtc_task_lock);
833	spin_unlock_irq(&rtc_lock);
834	return 0;
835	#endif
836	}
837	EXPORT_SYMBOL(rtc_register);
838
839	int rtc_unregister(rtc_task_t *task)
840	{
841	#ifndef RTC_IRQ
842	return -EIO;
843	#else
844	unsigned char tmp;
845
846	spin_lock_irq(&rtc_lock);
847	spin_lock(&rtc_task_lock);
848	if (rtc_callback != task) {
849	spin_unlock(&rtc_task_lock);
850	spin_unlock_irq(&rtc_lock);
851	return -ENXIO;
852	}
853	rtc_callback = NULL;
854
855	/* disable controls */
856	if (!hpet_mask_rtc_irq_bit(RTC_PIE \| RTC_AIE \| RTC_UIE)) {
857	tmp = CMOS_READ(RTC_CONTROL);
858	tmp &= ~RTC_PIE;
859	tmp &= ~RTC_AIE;
860	tmp &= ~RTC_UIE;
861	CMOS_WRITE(tmp, RTC_CONTROL);
862	CMOS_READ(RTC_INTR_FLAGS);
863	}
864	if (rtc_status & RTC_TIMER_ON) {
865	rtc_status &= ~RTC_TIMER_ON;
866	del_timer(&rtc_irq_timer);
867	}
868	rtc_status &= ~RTC_IS_OPEN;
869	spin_unlock(&rtc_task_lock);
870	spin_unlock_irq(&rtc_lock);
871	return 0;
872	#endif
873	}
874	EXPORT_SYMBOL(rtc_unregister);
875
876	int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
877	{
878	#ifndef RTC_IRQ
879	return -EIO;
880	#else
881	unsigned long flags;
882	if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET)
883	return -EINVAL;
884	spin_lock_irqsave(&rtc_task_lock, flags);
885	if (rtc_callback != task) {
886	spin_unlock_irqrestore(&rtc_task_lock, flags);
887	return -ENXIO;
888	}
889	spin_unlock_irqrestore(&rtc_task_lock, flags);
890	return rtc_do_ioctl(cmd, arg, 1);
891	#endif
892	}
893	EXPORT_SYMBOL(rtc_control);
894
895	/*
896	* The various file operations we support.
897	*/
898
899	static const struct file_operations rtc_fops = {
900	.owner = THIS_MODULE,
901	.llseek = no_llseek,
902	.read = rtc_read,
903	#ifdef RTC_IRQ
904	.poll = rtc_poll,
905	#endif
906	.unlocked_ioctl = rtc_ioctl,
907	.open = rtc_open,
908	.release = rtc_release,
909	.fasync = rtc_fasync,
910	};
911
912	static struct miscdevice rtc_dev = {
913	.minor = RTC_MINOR,
914	.name = "rtc",
915	.fops = &rtc_fops,
916	};
917
918	#ifdef CONFIG_PROC_FS
919	static const struct file_operations rtc_proc_fops = {
920	.owner = THIS_MODULE,
921	.open = rtc_proc_open,
922	.read = seq_read,
923	.llseek = seq_lseek,
924	.release = single_release,
925	};
926	#endif
927
928	static resource_size_t rtc_size;
929
930	static struct resource * __init rtc_request_region(resource_size_t size)
931	{
932	struct resource *r;
933
934	if (RTC_IOMAPPED)
935	r = request_region(RTC_PORT(0), size, "rtc");
936	else
937	r = request_mem_region(RTC_PORT(0), size, "rtc");
938
939	if (r)
940	rtc_size = size;
941
942	return r;
943	}
944
945	static void rtc_release_region(void)
946	{
947	if (RTC_IOMAPPED)
948	release_region(RTC_PORT(0), rtc_size);
949	else
950	release_mem_region(RTC_PORT(0), rtc_size);
951	}
952
953	static int __init rtc_init(void)
954	{
955	#ifdef CONFIG_PROC_FS
956	struct proc_dir_entry *ent;
957	#endif
958	#if defined(__alpha__) \|\| defined(__mips__)
959	unsigned int year, ctrl;
960	char *guess = NULL;
961	#endif
962	#ifdef CONFIG_SPARC32
963	struct device_node *ebus_dp;
964	struct platform_device *op;
965	#else
966	void *r;
967	#ifdef RTC_IRQ
968	irq_handler_t rtc_int_handler_ptr;
969	#endif
970	#endif
971
972	#ifdef CONFIG_SPARC32
973	for_each_node_by_name(ebus_dp, "ebus") {
974	struct device_node *dp;
975	for (dp = ebus_dp; dp; dp = dp->sibling) {
976	if (!strcmp(dp->name, "rtc")) {
977	op = of_find_device_by_node(dp);
978	if (op) {
979	rtc_port = op->resource[0].start;
980	rtc_irq = op->irqs[0];
981	goto found;
982	}
983	}
984	}
985	}
986	rtc_has_irq = 0;
987	printk(KERN_ERR "rtc_init: no PC rtc found\n");
988	return -EIO;
989
990	found:
991	if (!rtc_irq) {
992	rtc_has_irq = 0;
993	goto no_irq;
994	}
995
996	/*
997	* XXX Interrupt pin #7 in Espresso is shared between RTC and
998	* PCI Slot 2 INTA# (and some INTx# in Slot 1).
999	*/
1000	if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc",
1001	(void *)&rtc_port)) {
1002	rtc_has_irq = 0;
1003	printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq);
1004	return -EIO;
1005	}
1006	no_irq:
1007	#else
1008	r = rtc_request_region(RTC_IO_EXTENT);
1009
1010	/*
1011	* If we've already requested a smaller range (for example, because
1012	* PNPBIOS or ACPI told us how the device is configured), the request
1013	* above might fail because it's too big.
1014	*
1015	* If so, request just the range we actually use.
1016	*/
1017	if (!r)
1018	r = rtc_request_region(RTC_IO_EXTENT_USED);
1019	if (!r) {
1020	#ifdef RTC_IRQ
1021	rtc_has_irq = 0;
1022	#endif
1023	printk(KERN_ERR "rtc: I/O resource %lx is not free.\n",
1024	(long)(RTC_PORT(0)));
1025	return -EIO;
1026	}
1027
1028	#ifdef RTC_IRQ
1029	if (is_hpet_enabled()) {
1030	int err;
1031
1032	rtc_int_handler_ptr = hpet_rtc_interrupt;
1033	err = hpet_register_irq_handler(rtc_interrupt);
1034	if (err != 0) {
1035	printk(KERN_WARNING "hpet_register_irq_handler failed "
1036	"in rtc_init().");
1037	return err;
1038	}
1039	} else {
1040	rtc_int_handler_ptr = rtc_interrupt;
1041	}
1042
1043	if (request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED,
1044	"rtc", NULL)) {
1045	/* Yeah right, seeing as irq 8 doesn't even hit the bus. */
1046	rtc_has_irq = 0;
1047	printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
1048	rtc_release_region();
1049
1050	return -EIO;
1051	}
1052	hpet_rtc_timer_init();
1053
1054	#endif
1055
1056	#endif /* CONFIG_SPARC32 vs. others */
1057
1058	if (misc_register(&rtc_dev)) {
1059	#ifdef RTC_IRQ
1060	free_irq(RTC_IRQ, NULL);
1061	hpet_unregister_irq_handler(rtc_interrupt);
1062	rtc_has_irq = 0;
1063	#endif
1064	rtc_release_region();
1065	return -ENODEV;
1066	}
1067
1068	#ifdef CONFIG_PROC_FS
1069	ent = proc_create("driver/rtc", 0, NULL, &rtc_proc_fops);
1070	if (!ent)
1071	printk(KERN_WARNING "rtc: Failed to register with procfs.\n");
1072	#endif
1073
1074	#if defined(__alpha__) \|\| defined(__mips__)
1075	rtc_freq = HZ;
1076
1077	/* Each operating system on an Alpha uses its own epoch.
1078	Let's try to guess which one we are using now. */
1079
1080	if (rtc_is_updating() != 0)
1081	msleep(20);
1082
1083	spin_lock_irq(&rtc_lock);
1084	year = CMOS_READ(RTC_YEAR);
1085	ctrl = CMOS_READ(RTC_CONTROL);
1086	spin_unlock_irq(&rtc_lock);
1087
1088	if (!(ctrl & RTC_DM_BINARY) \|\| RTC_ALWAYS_BCD)
1089	year = bcd2bin(year); /* This should never happen... */
1090
1091	if (year < 20) {
1092	epoch = 2000;
1093	guess = "SRM (post-2000)";
1094	} else if (year >= 20 && year < 48) {
1095	epoch = 1980;
1096	guess = "ARC console";
1097	} else if (year >= 48 && year < 72) {
1098	epoch = 1952;
1099	guess = "Digital UNIX";
1100	#if defined(__mips__)
1101	} else if (year >= 72 && year < 74) {
1102	epoch = 2000;
1103	guess = "Digital DECstation";
1104	#else
1105	} else if (year >= 70) {
1106	epoch = 1900;
1107	guess = "Standard PC (1900)";
1108	#endif
1109	}
1110	if (guess)
1111	printk(KERN_INFO "rtc: %s epoch (%lu) detected\n",
1112	guess, epoch);
1113	#endif
1114	#ifdef RTC_IRQ
1115	if (rtc_has_irq == 0)
1116	goto no_irq2;
1117
1118	spin_lock_irq(&rtc_lock);
1119	rtc_freq = 1024;
1120	if (!hpet_set_periodic_freq(rtc_freq)) {
1121	/*
1122	* Initialize periodic frequency to CMOS reset default,
1123	* which is 1024Hz
1124	*/
1125	CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) \| 0x06),
1126	RTC_FREQ_SELECT);
1127	}
1128	spin_unlock_irq(&rtc_lock);
1129	no_irq2:
1130	#endif
1131
1132	(void) init_sysctl();
1133
1134	printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
1135
1136	return 0;
1137	}
1138
1139	static void __exit rtc_exit(void)
1140	{
1141	cleanup_sysctl();
1142	remove_proc_entry("driver/rtc", NULL);
1143	misc_deregister(&rtc_dev);
1144
1145	#ifdef CONFIG_SPARC32
1146	if (rtc_has_irq)
1147	free_irq(rtc_irq, &rtc_port);
1148	#else
1149	rtc_release_region();
1150	#ifdef RTC_IRQ
1151	if (rtc_has_irq) {
1152	free_irq(RTC_IRQ, NULL);
1153	hpet_unregister_irq_handler(hpet_rtc_interrupt);
1154	}
1155	#endif
1156	#endif /* CONFIG_SPARC32 */
1157	}
1158
1159	module_init(rtc_init);
1160	module_exit(rtc_exit);
1161
1162	#ifdef RTC_IRQ
1163	/*
1164	* At IRQ rates >= 4096Hz, an interrupt may get lost altogether.
1165	* (usually during an IDE disk interrupt, with IRQ unmasking off)
1166	* Since the interrupt handler doesn't get called, the IRQ status
1167	* byte doesn't get read, and the RTC stops generating interrupts.
1168	* A timer is set, and will call this function if/when that happens.
1169	* To get it out of this stalled state, we just read the status.
1170	* At least a jiffy of interrupts (rtc_freq/HZ) will have been lost.
1171	* (You really shouldn't be trying to use a non-realtime system
1172	* for something that requires a steady > 1KHz signal anyways.)
1173	*/
1174
1175	static void rtc_dropped_irq(unsigned long data)
1176	{
1177	unsigned long freq;
1178
1179	spin_lock_irq(&rtc_lock);
1180
1181	if (hpet_rtc_dropped_irq()) {
1182	spin_unlock_irq(&rtc_lock);
1183	return;
1184	}
1185
1186	/* Just in case someone disabled the timer from behind our back... */
1187	if (rtc_status & RTC_TIMER_ON)
1188	mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
1189
1190	rtc_irq_data += ((rtc_freq/HZ)<<8);
1191	rtc_irq_data &= ~0xff;
1192	rtc_irq_data \|= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */
1193
1194	freq = rtc_freq;
1195
1196	spin_unlock_irq(&rtc_lock);
1197
1198	printk_ratelimited(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n",
1199	freq);
1200
1201	/* Now we have new data */
1202	wake_up_interruptible(&rtc_wait);
1203
1204	kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
1205	}
1206	#endif
1207
1208	#ifdef CONFIG_PROC_FS
1209	/*
1210	* Info exported via "/proc/driver/rtc".
1211	*/
1212
1213	static int rtc_proc_show(struct seq_file seq, void v)
1214	{
1215	#define YN(bit) ((ctrl & bit) ? "yes" : "no")
1216	#define NY(bit) ((ctrl & bit) ? "no" : "yes")
1217	struct rtc_time tm;
1218	unsigned char batt, ctrl;
1219	unsigned long freq;
1220
1221	spin_lock_irq(&rtc_lock);
1222	batt = CMOS_READ(RTC_VALID) & RTC_VRT;
1223	ctrl = CMOS_READ(RTC_CONTROL);
1224	freq = rtc_freq;
1225	spin_unlock_irq(&rtc_lock);
1226
1227
1228	rtc_get_rtc_time(&tm);
1229
1230	/*
1231	* There is no way to tell if the luser has the RTC set for local
1232	* time or for Universal Standard Time (GMT). Probably local though.
1233	*/
1234	seq_printf(seq,
1235	"rtc_time\t: %02d:%02d:%02d\n"
1236	"rtc_date\t: %04d-%02d-%02d\n"
1237	"rtc_epoch\t: %04lu\n",
1238	tm.tm_hour, tm.tm_min, tm.tm_sec,
1239	tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
1240
1241	get_rtc_alm_time(&tm);
1242
1243	/*
1244	* We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
1245	* match any value for that particular field. Values that are
1246	* greater than a valid time, but less than 0xc0 shouldn't appear.
1247	*/
1248	seq_puts(seq, "alarm\t\t: ");
1249	if (tm.tm_hour <= 24)
1250	seq_printf(seq, "%02d:", tm.tm_hour);
1251	else
1252	seq_puts(seq, "**:");
1253
1254	if (tm.tm_min <= 59)
1255	seq_printf(seq, "%02d:", tm.tm_min);
1256	else
1257	seq_puts(seq, "**:");
1258
1259	if (tm.tm_sec <= 59)
1260	seq_printf(seq, "%02d\n", tm.tm_sec);
1261	else
1262	seq_puts(seq, "**\n");
1263
1264	seq_printf(seq,
1265	"DST_enable\t: %s\n"
1266	"BCD\t\t: %s\n"
1267	"24hr\t\t: %s\n"
1268	"square_wave\t: %s\n"
1269	"alarm_IRQ\t: %s\n"
1270	"update_IRQ\t: %s\n"
1271	"periodic_IRQ\t: %s\n"
1272	"periodic_freq\t: %ld\n"
1273	"batt_status\t: %s\n",
1274	YN(RTC_DST_EN),
1275	NY(RTC_DM_BINARY),
1276	YN(RTC_24H),
1277	YN(RTC_SQWE),
1278	YN(RTC_AIE),
1279	YN(RTC_UIE),
1280	YN(RTC_PIE),
1281	freq,
1282	batt ? "okay" : "dead");
1283
1284	return 0;
1285	#undef YN
1286	#undef NY
1287	}
1288
1289	static int rtc_proc_open(struct inode inode, struct file file)
1290	{
1291	return single_open(file, rtc_proc_show, NULL);
1292	}
1293	#endif
1294
1295	static void rtc_get_rtc_time(struct rtc_time *rtc_tm)
1296	{
1297	unsigned long uip_watchdog = jiffies, flags;
1298	unsigned char ctrl;
1299	#ifdef CONFIG_MACH_DECSTATION
1300	unsigned int real_year;
1301	#endif
1302
1303	/*
1304	* read RTC once any update in progress is done. The update
1305	* can take just over 2ms. We wait 20ms. There is no need to
1306	* to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
1307	* If you need to know exactly when a second has started, enable
1308	* periodic update complete interrupts, (via ioctl) and then
1309	* immediately read /dev/rtc which will block until you get the IRQ.
1310	* Once the read clears, read the RTC time (again via ioctl). Easy.
1311	*/
1312
1313	while (rtc_is_updating() != 0 &&
1314	time_before(jiffies, uip_watchdog + 2*HZ/100))
1315	cpu_relax();
1316
1317	/*
1318	* Only the values that we read from the RTC are set. We leave
1319	* tm_wday, tm_yday and tm_isdst untouched. Note that while the
1320	* RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is
1321	* only updated by the RTC when initially set to a non-zero value.
1322	*/
1323	spin_lock_irqsave(&rtc_lock, flags);
1324	rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
1325	rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
1326	rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
1327	rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
1328	rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
1329	rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
1330	/* Only set from 2.6.16 onwards */
1331	rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK);
1332
1333	#ifdef CONFIG_MACH_DECSTATION
1334	real_year = CMOS_READ(RTC_DEC_YEAR);
1335	#endif
1336	ctrl = CMOS_READ(RTC_CONTROL);
1337	spin_unlock_irqrestore(&rtc_lock, flags);
1338
1339	if (!(ctrl & RTC_DM_BINARY) \|\| RTC_ALWAYS_BCD) {
1340	rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
1341	rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
1342	rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
1343	rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
1344	rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
1345	rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
1346	rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
1347	}
1348
1349	#ifdef CONFIG_MACH_DECSTATION
1350	rtc_tm->tm_year += real_year - 72;
1351	#endif
1352
1353	/*
1354	* Account for differences between how the RTC uses the values
1355	* and how they are defined in a struct rtc_time;
1356	*/
1357	rtc_tm->tm_year += epoch - 1900;
1358	if (rtc_tm->tm_year <= 69)
1359	rtc_tm->tm_year += 100;
1360
1361	rtc_tm->tm_mon--;
1362	}
1363
1364	static void get_rtc_alm_time(struct rtc_time *alm_tm)
1365	{
1366	unsigned char ctrl;
1367
1368	/*
1369	* Only the values that we read from the RTC are set. That
1370	* means only tm_hour, tm_min, and tm_sec.
1371	*/
1372	spin_lock_irq(&rtc_lock);
1373	alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
1374	alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM);
1375	alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM);
1376	ctrl = CMOS_READ(RTC_CONTROL);
1377	spin_unlock_irq(&rtc_lock);
1378
1379	if (!(ctrl & RTC_DM_BINARY) \|\| RTC_ALWAYS_BCD) {
1380	alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
1381	alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
1382	alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
1383	}
1384	}
1385
1386	#ifdef RTC_IRQ
1387	/*
1388	* Used to disable/enable interrupts for any one of UIE, AIE, PIE.
1389	* Rumour has it that if you frob the interrupt enable/disable
1390	* bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to
1391	* ensure you actually start getting interrupts. Probably for
1392	* compatibility with older/broken chipset RTC implementations.
1393	* We also clear out any old irq data after an ioctl() that
1394	* meddles with the interrupt enable/disable bits.
1395	*/
1396
1397	static void mask_rtc_irq_bit_locked(unsigned char bit)
1398	{
1399	unsigned char val;
1400
1401	if (hpet_mask_rtc_irq_bit(bit))
1402	return;
1403	val = CMOS_READ(RTC_CONTROL);
1404	val &= ~bit;
1405	CMOS_WRITE(val, RTC_CONTROL);
1406	CMOS_READ(RTC_INTR_FLAGS);
1407
1408	rtc_irq_data = 0;
1409	}
1410
1411	static void set_rtc_irq_bit_locked(unsigned char bit)
1412	{
1413	unsigned char val;
1414
1415	if (hpet_set_rtc_irq_bit(bit))
1416	return;
1417	val = CMOS_READ(RTC_CONTROL);
1418	val \|= bit;
1419	CMOS_WRITE(val, RTC_CONTROL);
1420	CMOS_READ(RTC_INTR_FLAGS);
1421
1422	rtc_irq_data = 0;
1423	}
1424	#endif
1425
1426	MODULE_AUTHOR("Paul Gortmaker");
1427	MODULE_LICENSE("GPL");
1428	MODULE_ALIAS_MISCDEV(RTC_MINOR);
1429

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