pcrtc.c revision 130174
193023Snsouch/*-
293023Snsouch * Copyright (c) 1990 The Regents of the University of California.
393023Snsouch * All rights reserved.
493023Snsouch *
593023Snsouch * This code is derived from software contributed to Berkeley by
693023Snsouch * William Jolitz and Don Ahn.
793023Snsouch *
893023Snsouch * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 *	from: @(#)clock.c	7.2 (Berkeley) 5/12/91
33 * $FreeBSD: head/sys/pc98/cbus/pcrtc.c 130174 2004-06-07 06:04:27Z phk $
34 */
35
36/*
37 * Routines to handle clock hardware.
38 */
39
40/*
41 * inittodr, settodr and support routines written
42 * by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>
43 *
44 * reintroduced and updated by Chris Stenton <chris@gnome.co.uk> 8/10/94
45 */
46
47/*
48 * modified for PC98 by Kakefuda
49 */
50
51#include "opt_clock.h"
52#include "opt_isa.h"
53#include "opt_mca.h"
54
55#include <sys/param.h>
56#include <sys/systm.h>
57#include <sys/bus.h>
58#include <sys/limits.h>
59#include <sys/lock.h>
60#include <sys/module.h>
61#include <sys/mutex.h>
62#include <sys/proc.h>
63#include <sys/time.h>
64#include <sys/timetc.h>
65#include <sys/kernel.h>
66#include <sys/sysctl.h>
67#include <sys/cons.h>
68#include <sys/power.h>
69
70#include <machine/clock.h>
71#include <machine/cputypes.h>
72#include <machine/frame.h>
73#include <machine/intr_machdep.h>
74#include <machine/md_var.h>
75#include <machine/psl.h>
76
77#if defined(SMP)
78#include <machine/smp.h>
79#endif
80#include <machine/specialreg.h>
81
82#include <i386/isa/icu.h>
83#include <pc98/pc98/pc98.h>
84#include <pc98/pc98/pc98_machdep.h>
85#ifdef DEV_ISA
86#include <isa/isavar.h>
87#endif
88#include <i386/isa/timerreg.h>
89
90/*
91 * 32-bit time_t's can't reach leap years before 1904 or after 2036, so we
92 * can use a simple formula for leap years.
93 */
94#define	LEAPYEAR(y) (((u_int)(y) % 4 == 0) ? 1 : 0)
95#define DAYSPERYEAR   (31+28+31+30+31+30+31+31+30+31+30+31)
96
97#define	TIMER_DIV(x) ((timer_freq + (x) / 2) / (x))
98
99#ifndef BURN_BRIDGES
100/*
101 * Time in timer cycles that it takes for microtime() to disable interrupts
102 * and latch the count.  microtime() currently uses "cli; outb ..." so it
103 * normally takes less than 2 timer cycles.  Add a few for cache misses.
104 * Add a few more to allow for latency in bogus calls to microtime() with
105 * interrupts already disabled.
106 */
107#define	TIMER0_LATCH_COUNT	20
108
109/*
110 * Maximum frequency that we are willing to allow for timer0.  Must be
111 * low enough to guarantee that the timer interrupt handler returns
112 * before the next timer interrupt.
113 */
114#define	TIMER0_MAX_FREQ		20000
115#endif
116
117int	adjkerntz;		/* local offset from GMT in seconds */
118int	clkintr_pending;
119int	disable_rtc_set;	/* disable resettodr() if != 0 */
120int	pscnt = 1;
121int	psdiv = 1;
122int	statclock_disable;
123#ifndef TIMER_FREQ
124#define TIMER_FREQ   2457600
125#endif
126u_int	timer_freq = TIMER_FREQ;
127int	timer0_max_count;
128int	wall_cmos_clock;	/* wall CMOS clock assumed if != 0 */
129struct mtx clock_lock;
130
131static	int	beeping = 0;
132static	const u_char daysinmonth[] = {31,28,31,30,31,30,31,31,30,31,30,31};
133static	u_int	hardclock_max_count;
134static	u_int32_t i8254_lastcount;
135static	u_int32_t i8254_offset;
136static	int	i8254_ticked;
137static	struct intsrc *i8254_intsrc;
138#ifndef BURN_BRIDGES
139/*
140 * XXX new_function and timer_func should not handle clockframes, but
141 * timer_func currently needs to hold hardclock to handle the
142 * timer0_state == 0 case.  We should use inthand_add()/inthand_remove()
143 * to switch between clkintr() and a slightly different timerintr().
144 */
145static	void	(*new_function)(struct clockframe *frame);
146static	u_int	new_rate;
147static	u_int	timer0_prescaler_count;
148static	u_char	timer0_state;
149#endif
150
151/* Values for timerX_state: */
152#define	RELEASED	0
153#define	RELEASE_PENDING	1
154#define	ACQUIRED	2
155#define	ACQUIRE_PENDING	3
156
157static 	u_char	timer1_state;
158static	u_char	timer2_state;
159static	void	(*timer_func)(struct clockframe *frame) = hardclock;
160static void rtc_serialcombit(int);
161static void rtc_serialcom(int);
162static int rtc_inb(void);
163static void rtc_outb(int);
164
165static	unsigned i8254_get_timecount(struct timecounter *tc);
166static	void	set_timer_freq(u_int freq, int intr_freq);
167
168static struct timecounter i8254_timecounter = {
169	i8254_get_timecount,	/* get_timecount */
170	0,			/* no poll_pps */
171	~0u,			/* counter_mask */
172	0,			/* frequency */
173	"i8254",		/* name */
174	0			/* quality */
175};
176
177static void
178clkintr(struct clockframe *frame)
179{
180
181	if (timecounter->tc_get_timecount == i8254_get_timecount) {
182		mtx_lock_spin(&clock_lock);
183		if (i8254_ticked)
184			i8254_ticked = 0;
185		else {
186			i8254_offset += timer0_max_count;
187			i8254_lastcount = 0;
188		}
189		clkintr_pending = 0;
190		mtx_unlock_spin(&clock_lock);
191	}
192	timer_func(frame);
193#ifdef SMP
194	if (timer_func == hardclock)
195		forward_hardclock();
196#endif
197#ifndef BURN_BRIDGES
198	switch (timer0_state) {
199
200	case RELEASED:
201		break;
202
203	case ACQUIRED:
204		if ((timer0_prescaler_count += timer0_max_count)
205		    >= hardclock_max_count) {
206			timer0_prescaler_count -= hardclock_max_count;
207			hardclock(frame);
208#ifdef SMP
209			forward_hardclock();
210#endif
211		}
212		break;
213
214	case ACQUIRE_PENDING:
215		mtx_lock_spin(&clock_lock);
216		i8254_offset = i8254_get_timecount(NULL);
217		i8254_lastcount = 0;
218		timer0_max_count = TIMER_DIV(new_rate);
219		outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
220		outb(TIMER_CNTR0, timer0_max_count & 0xff);
221		outb(TIMER_CNTR0, timer0_max_count >> 8);
222		mtx_unlock_spin(&clock_lock);
223		timer_func = new_function;
224		timer0_state = ACQUIRED;
225		break;
226
227	case RELEASE_PENDING:
228		if ((timer0_prescaler_count += timer0_max_count)
229		    >= hardclock_max_count) {
230			mtx_lock_spin(&clock_lock);
231			i8254_offset = i8254_get_timecount(NULL);
232			i8254_lastcount = 0;
233			timer0_max_count = hardclock_max_count;
234			outb(TIMER_MODE,
235			     TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
236			outb(TIMER_CNTR0, timer0_max_count & 0xff);
237			outb(TIMER_CNTR0, timer0_max_count >> 8);
238			mtx_unlock_spin(&clock_lock);
239			timer0_prescaler_count = 0;
240			timer_func = hardclock;
241			timer0_state = RELEASED;
242			hardclock(frame);
243#ifdef SMP
244			forward_hardclock();
245#endif
246		}
247		break;
248	}
249#endif
250}
251
252#ifndef BURN_BRIDGES
253/*
254 * The acquire and release functions must be called at ipl >= splclock().
255 */
256int
257acquire_timer0(int rate, void (*function)(struct clockframe *frame))
258{
259	static int old_rate;
260
261	if (rate <= 0 || rate > TIMER0_MAX_FREQ)
262		return (-1);
263	switch (timer0_state) {
264
265	case RELEASED:
266		timer0_state = ACQUIRE_PENDING;
267		break;
268
269	case RELEASE_PENDING:
270		if (rate != old_rate)
271			return (-1);
272		/*
273		 * The timer has been released recently, but is being
274		 * re-acquired before the release completed.  In this
275		 * case, we simply reclaim it as if it had not been
276		 * released at all.
277		 */
278		timer0_state = ACQUIRED;
279		break;
280
281	default:
282		return (-1);	/* busy */
283	}
284	new_function = function;
285	old_rate = new_rate = rate;
286	return (0);
287}
288#endif
289
290int
291acquire_timer1(int mode)
292{
293
294	if (timer1_state != RELEASED)
295		return (-1);
296	timer1_state = ACQUIRED;
297
298	/*
299	 * This access to the timer registers is as atomic as possible
300	 * because it is a single instruction.  We could do better if we
301	 * knew the rate.  Use of splclock() limits glitches to 10-100us,
302	 * and this is probably good enough for timer2, so we aren't as
303	 * careful with it as with timer0.
304	 */
305	outb(TIMER_MODE, TIMER_SEL1 | (mode & 0x3f));
306
307	return (0);
308}
309
310int
311acquire_timer2(int mode)
312{
313
314	if (timer2_state != RELEASED)
315		return (-1);
316	timer2_state = ACQUIRED;
317
318	/*
319	 * This access to the timer registers is as atomic as possible
320	 * because it is a single instruction.  We could do better if we
321	 * knew the rate.  Use of splclock() limits glitches to 10-100us,
322	 * and this is probably good enough for timer2, so we aren't as
323	 * careful with it as with timer0.
324	 */
325	outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f));
326
327	return (0);
328}
329
330#ifndef BURN_BRIDGES
331int
332release_timer0()
333{
334	switch (timer0_state) {
335
336	case ACQUIRED:
337		timer0_state = RELEASE_PENDING;
338		break;
339
340	case ACQUIRE_PENDING:
341		/* Nothing happened yet, release quickly. */
342		timer0_state = RELEASED;
343		break;
344
345	default:
346		return (-1);
347	}
348	return (0);
349}
350#endif
351
352int
353release_timer1()
354{
355
356	if (timer1_state != ACQUIRED)
357		return (-1);
358	timer1_state = RELEASED;
359	outb(TIMER_MODE, TIMER_SEL1 | TIMER_SQWAVE | TIMER_16BIT);
360	return (0);
361}
362
363int
364release_timer2()
365{
366
367	if (timer2_state != ACQUIRED)
368		return (-1);
369	timer2_state = RELEASED;
370	outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT);
371	return (0);
372}
373
374
375static int
376getit(void)
377{
378	int high, low;
379
380	mtx_lock_spin(&clock_lock);
381
382	/* Select timer0 and latch counter value. */
383	outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
384
385	low = inb(TIMER_CNTR0);
386	high = inb(TIMER_CNTR0);
387
388	mtx_unlock_spin(&clock_lock);
389	return ((high << 8) | low);
390}
391
392/*
393 * Wait "n" microseconds.
394 * Relies on timer 1 counting down from (timer_freq / hz)
395 * Note: timer had better have been programmed before this is first used!
396 */
397void
398DELAY(int n)
399{
400	int delta, prev_tick, tick, ticks_left;
401
402#ifdef DELAYDEBUG
403	int getit_calls = 1;
404	int n1;
405	static int state = 0;
406
407	if (state == 0) {
408		state = 1;
409		for (n1 = 1; n1 <= 10000000; n1 *= 10)
410			DELAY(n1);
411		state = 2;
412	}
413	if (state == 1)
414		printf("DELAY(%d)...", n);
415#endif
416	/*
417	 * Guard against the timer being uninitialized if we are called
418	 * early for console i/o.
419	 */
420	if (timer0_max_count == 0)
421		set_timer_freq(timer_freq, hz);
422
423	/*
424	 * Read the counter first, so that the rest of the setup overhead is
425	 * counted.  Guess the initial overhead is 20 usec (on most systems it
426	 * takes about 1.5 usec for each of the i/o's in getit().  The loop
427	 * takes about 6 usec on a 486/33 and 13 usec on a 386/20.  The
428	 * multiplications and divisions to scale the count take a while).
429	 *
430	 * However, if ddb is active then use a fake counter since reading
431	 * the i8254 counter involves acquiring a lock.  ddb must not go
432	 * locking for many reasons, but it calls here for at least atkbd
433	 * input.
434	 */
435#ifdef DDB
436	if (db_active)
437		prev_tick = 0;
438	else
439#endif
440		prev_tick = getit();
441	n -= 0;			/* XXX actually guess no initial overhead */
442	/*
443	 * Calculate (n * (timer_freq / 1e6)) without using floating point
444	 * and without any avoidable overflows.
445	 */
446	if (n <= 0)
447		ticks_left = 0;
448	else if (n < 256)
449		/*
450		 * Use fixed point to avoid a slow division by 1000000.
451		 * 39099 = 1193182 * 2^15 / 10^6 rounded to nearest.
452		 * 2^15 is the first power of 2 that gives exact results
453		 * for n between 0 and 256.
454		 */
455		ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15;
456	else
457		/*
458		 * Don't bother using fixed point, although gcc-2.7.2
459		 * generates particularly poor code for the long long
460		 * division, since even the slow way will complete long
461		 * before the delay is up (unless we're interrupted).
462		 */
463		ticks_left = ((u_int)n * (long long)timer_freq + 999999)
464			     / 1000000;
465
466	while (ticks_left > 0) {
467#ifdef DDB
468		if (db_active) {
469			outb(0x5f, 0);
470			tick = prev_tick + 1;
471		} else
472#endif
473			tick = getit();
474#ifdef DELAYDEBUG
475		++getit_calls;
476#endif
477		delta = prev_tick - tick;
478		prev_tick = tick;
479		if (delta < 0) {
480			delta += timer0_max_count;
481			/*
482			 * Guard against timer0_max_count being wrong.
483			 * This shouldn't happen in normal operation,
484			 * but it may happen if set_timer_freq() is
485			 * traced.
486			 */
487			if (delta < 0)
488				delta = 0;
489		}
490		ticks_left -= delta;
491	}
492#ifdef DELAYDEBUG
493	if (state == 1)
494		printf(" %d calls to getit() at %d usec each\n",
495		       getit_calls, (n + 5) / getit_calls);
496#endif
497}
498
499static void
500sysbeepstop(void *chan)
501{
502	outb(IO_PPI, inb(IO_PPI)|0x08);	/* disable counter1 output to speaker */
503	release_timer1();
504	beeping = 0;
505}
506
507int
508sysbeep(int pitch, int period)
509{
510	int x = splclock();
511
512	if (acquire_timer1(TIMER_SQWAVE|TIMER_16BIT))
513		if (!beeping) {
514			/* Something else owns it. */
515			splx(x);
516			return (-1); /* XXX Should be EBUSY, but nobody cares anyway. */
517		}
518	disable_intr();
519	outb(0x3fdb, pitch);
520	outb(0x3fdb, (pitch>>8));
521	enable_intr();
522	if (!beeping) {
523		/* enable counter1 output to speaker */
524		outb(IO_PPI, (inb(IO_PPI) & 0xf7));
525		beeping = period;
526		timeout(sysbeepstop, (void *)NULL, period);
527	}
528	splx(x);
529	return (0);
530}
531
532
533unsigned int delaycount;
534#define FIRST_GUESS	0x2000
535static void findcpuspeed(void)
536{
537	int i;
538	int remainder;
539
540	/* Put counter in count down mode */
541	outb(TIMER_MODE, TIMER_SEL0 | TIMER_16BIT | TIMER_RATEGEN);
542	outb(TIMER_CNTR0, 0xff);
543	outb(TIMER_CNTR0, 0xff);
544	for (i = FIRST_GUESS; i; i--)
545		;
546	remainder = getit();
547	delaycount = (FIRST_GUESS * TIMER_DIV(1000)) / (0xffff - remainder);
548}
549
550static u_int
551calibrate_clocks(void)
552{
553	int	timeout;
554	u_int	count, prev_count, tot_count;
555	u_short	sec, start_sec;
556
557	if (bootverbose)
558	        printf("Calibrating clock(s) ... ");
559	/* Check ARTIC. */
560	if (!(PC98_SYSTEM_PARAMETER(0x458) & 0x80) &&
561	    !(PC98_SYSTEM_PARAMETER(0x45b) & 0x04))
562		goto fail;
563	timeout = 100000000;
564
565	/* Read the ARTIC. */
566	sec = inw(0x5e);
567
568	/* Wait for the ARTIC to changes. */
569	start_sec = sec;
570	for (;;) {
571		sec = inw(0x5e);
572		if (sec != start_sec)
573			break;
574		if (--timeout == 0)
575			goto fail;
576	}
577	prev_count = getit();
578	if (prev_count == 0 || prev_count > timer0_max_count)
579		goto fail;
580	tot_count = 0;
581
582	start_sec = sec;
583	for (;;) {
584		sec = inw(0x5e);
585		count = getit();
586		if (count == 0 || count > timer0_max_count)
587			goto fail;
588		if (count > prev_count)
589			tot_count += prev_count - (count - timer0_max_count);
590		else
591			tot_count += prev_count - count;
592		prev_count = count;
593		if ((sec == start_sec + 1200) || /* 1200 = 307.2KHz >> 8 */
594		    (sec < start_sec &&
595		        (u_int)sec + 0x10000 == (u_int)start_sec + 1200))
596			break;
597		if (--timeout == 0)
598			goto fail;
599	}
600
601	if (bootverbose) {
602	        printf("i8254 clock: %u Hz\n", tot_count);
603	}
604	return (tot_count);
605
606fail:
607	if (bootverbose)
608	        printf("failed, using default i8254 clock of %u Hz\n",
609		       timer_freq);
610	return (timer_freq);
611}
612
613static void
614set_timer_freq(u_int freq, int intr_freq)
615{
616	int new_timer0_max_count;
617
618	mtx_lock_spin(&clock_lock);
619	timer_freq = freq;
620	new_timer0_max_count = hardclock_max_count = TIMER_DIV(intr_freq);
621	if (new_timer0_max_count != timer0_max_count) {
622		timer0_max_count = new_timer0_max_count;
623		outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
624		outb(TIMER_CNTR0, timer0_max_count & 0xff);
625		outb(TIMER_CNTR0, timer0_max_count >> 8);
626	}
627	mtx_unlock_spin(&clock_lock);
628}
629
630static void
631i8254_restore(void)
632{
633
634	mtx_lock_spin(&clock_lock);
635	outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
636	outb(TIMER_CNTR0, timer0_max_count & 0xff);
637	outb(TIMER_CNTR0, timer0_max_count >> 8);
638	mtx_unlock_spin(&clock_lock);
639}
640
641
642/*
643 * Restore all the timers non-atomically (XXX: should be atomically).
644 *
645 * This function is called from pmtimer_resume() to restore all the timers.
646 * This should not be necessary, but there are broken laptops that do not
647 * restore all the timers on resume.
648 */
649void
650timer_restore(void)
651{
652
653	i8254_restore();		/* restore timer_freq and hz */
654}
655
656/*
657 * Initialize 8254 timer 0 early so that it can be used in DELAY().
658 * XXX initialization of other timers is unintentionally left blank.
659 */
660void
661startrtclock()
662{
663	u_int delta, freq;
664
665	findcpuspeed();
666	if (pc98_machine_type & M_8M)
667		timer_freq = 1996800L; /* 1.9968 MHz */
668	else
669		timer_freq = 2457600L; /* 2.4576 MHz */
670
671	set_timer_freq(timer_freq, hz);
672	freq = calibrate_clocks();
673#ifdef CLK_CALIBRATION_LOOP
674	if (bootverbose) {
675		printf(
676		"Press a key on the console to abort clock calibration\n");
677		while (cncheckc() == -1)
678			calibrate_clocks();
679	}
680#endif
681
682	/*
683	 * Use the calibrated i8254 frequency if it seems reasonable.
684	 * Otherwise use the default, and don't use the calibrated i586
685	 * frequency.
686	 */
687	delta = freq > timer_freq ? freq - timer_freq : timer_freq - freq;
688	if (delta < timer_freq / 100) {
689#ifndef CLK_USE_I8254_CALIBRATION
690		if (bootverbose)
691			printf(
692"CLK_USE_I8254_CALIBRATION not specified - using default frequency\n");
693		freq = timer_freq;
694#endif
695		timer_freq = freq;
696	} else {
697		if (bootverbose)
698			printf(
699		    "%d Hz differs from default of %d Hz by more than 1%%\n",
700			       freq, timer_freq);
701	}
702
703	set_timer_freq(timer_freq, hz);
704	i8254_timecounter.tc_frequency = timer_freq;
705	tc_init(&i8254_timecounter);
706
707	init_TSC();
708}
709
710static void
711rtc_serialcombit(int i)
712{
713	outb(IO_RTC, ((i&0x01)<<5)|0x07);
714	DELAY(1);
715	outb(IO_RTC, ((i&0x01)<<5)|0x17);
716	DELAY(1);
717	outb(IO_RTC, ((i&0x01)<<5)|0x07);
718	DELAY(1);
719}
720
721static void
722rtc_serialcom(int i)
723{
724	rtc_serialcombit(i&0x01);
725	rtc_serialcombit((i&0x02)>>1);
726	rtc_serialcombit((i&0x04)>>2);
727	rtc_serialcombit((i&0x08)>>3);
728	outb(IO_RTC, 0x07);
729	DELAY(1);
730	outb(IO_RTC, 0x0f);
731	DELAY(1);
732	outb(IO_RTC, 0x07);
733 	DELAY(1);
734}
735
736static void
737rtc_outb(int val)
738{
739	int s;
740	int sa = 0;
741
742	for (s=0;s<8;s++) {
743	    sa = ((val >> s) & 0x01) ? 0x27 : 0x07;
744	    outb(IO_RTC, sa);		/* set DI & CLK 0 */
745	    DELAY(1);
746	    outb(IO_RTC, sa | 0x10);	/* CLK 1 */
747	    DELAY(1);
748	}
749	outb(IO_RTC, sa & 0xef);	/* CLK 0 */
750}
751
752static int
753rtc_inb(void)
754{
755	int s;
756	int sa = 0;
757
758	for (s=0;s<8;s++) {
759	    sa |= ((inb(0x33) & 0x01) << s);
760	    outb(IO_RTC, 0x17);	/* CLK 1 */
761	    DELAY(1);
762	    outb(IO_RTC, 0x07);	/* CLK 0 */
763	    DELAY(2);
764	}
765	return sa;
766}
767
768/*
769 * Initialize the time of day register, based on the time base which is, e.g.
770 * from a filesystem.
771 */
772void
773inittodr(time_t base)
774{
775	unsigned long	sec, days;
776	int		year, month;
777	int		y, m, s;
778	struct timespec ts;
779	int		second, min, hour;
780
781	if (base) {
782		s = splclock();
783		ts.tv_sec = base;
784		ts.tv_nsec = 0;
785		tc_setclock(&ts);
786		splx(s);
787	}
788
789	rtc_serialcom(0x03);	/* Time Read */
790	rtc_serialcom(0x01);	/* Register shift command. */
791	DELAY(20);
792
793	second = bcd2bin(rtc_inb() & 0xff);	/* sec */
794	min = bcd2bin(rtc_inb() & 0xff);	/* min */
795	hour = bcd2bin(rtc_inb() & 0xff);	/* hour */
796	days = bcd2bin(rtc_inb() & 0xff) - 1;	/* date */
797
798	month = (rtc_inb() >> 4) & 0x0f;	/* month */
799	for (m = 1; m <	month; m++)
800		days +=	daysinmonth[m-1];
801	year = bcd2bin(rtc_inb() & 0xff) + 1900;	/* year */
802	/* 2000 year problem */
803	if (year < 1995)
804		year += 100;
805	if (year < 1970)
806		goto wrong_time;
807	for (y = 1970; y < year; y++)
808		days +=	DAYSPERYEAR + LEAPYEAR(y);
809	if ((month > 2)	&& LEAPYEAR(year))
810		days ++;
811	sec = ((( days * 24 +
812		  hour) * 60 +
813		  min) * 60 +
814		  second);
815	/* sec now contains the	number of seconds, since Jan 1 1970,
816	   in the local	time zone */
817
818	s = splhigh();
819
820	sec += tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
821
822	y = time_second - sec;
823	if (y <= -2 || y >= 2) {
824		/* badly off, adjust it */
825		ts.tv_sec = sec;
826		ts.tv_nsec = 0;
827		tc_setclock(&ts);
828	}
829	splx(s);
830	return;
831
832wrong_time:
833	printf("Invalid time in real time clock.\n");
834	printf("Check and reset the date immediately!\n");
835}
836
837/*
838 * Write system time back to RTC
839 */
840void
841resettodr()
842{
843	unsigned long	tm;
844	int		y, m, s;
845	int		wd;
846
847	if (disable_rtc_set)
848		return;
849
850	s = splclock();
851	tm = time_second;
852	splx(s);
853
854	rtc_serialcom(0x01);	/* Register shift command. */
855
856	/* Calculate local time	to put in RTC */
857
858	tm -= tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
859
860	rtc_outb(bin2bcd(tm%60)); tm /= 60;	/* Write back Seconds */
861	rtc_outb(bin2bcd(tm%60)); tm /= 60;	/* Write back Minutes */
862	rtc_outb(bin2bcd(tm%24)); tm /= 24;	/* Write back Hours   */
863
864	/* We have now the days	since 01-01-1970 in tm */
865	wd = (tm + 4) % 7 + 1;			/* Write back Weekday */
866	for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
867	     tm >= m;
868	     y++,      m = DAYSPERYEAR + LEAPYEAR(y))
869	     tm -= m;
870
871	/* Now we have the years in y and the day-of-the-year in tm */
872	for (m = 0; ; m++) {
873		int ml;
874
875		ml = daysinmonth[m];
876		if (m == 1 && LEAPYEAR(y))
877			ml++;
878		if (tm < ml)
879			break;
880		tm -= ml;
881	}
882
883	m++;
884	rtc_outb(bin2bcd(tm+1));		/* Write back Day     */
885	rtc_outb((m << 4) | wd);		/* Write back Month & Weekday  */
886	rtc_outb(bin2bcd(y%100));		/* Write back Year    */
887
888	rtc_serialcom(0x02);	/* Time set & Counter hold command. */
889	rtc_serialcom(0x00);	/* Register hold command. */
890}
891
892
893/*
894 * Start both clocks running.
895 */
896void
897cpu_initclocks()
898{
899
900	/* Finish initializing 8254 timer 0. */
901	intr_add_handler("clk", 0, (driver_intr_t *)clkintr, NULL,
902	    INTR_TYPE_CLK | INTR_FAST, NULL);
903
904	init_TSC_tc();
905}
906
907void
908cpu_startprofclock(void)
909{
910}
911
912void
913cpu_stopprofclock(void)
914{
915}
916
917static int
918sysctl_machdep_i8254_freq(SYSCTL_HANDLER_ARGS)
919{
920	int error;
921	u_int freq;
922
923	/*
924	 * Use `i8254' instead of `timer' in external names because `timer'
925	 * is is too generic.  Should use it everywhere.
926	 */
927	freq = timer_freq;
928	error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
929	if (error == 0 && req->newptr != NULL) {
930#ifndef BURN_BRIDGES
931		if (timer0_state != RELEASED)
932			return (EBUSY);	/* too much trouble to handle */
933#endif
934		set_timer_freq(freq, hz);
935		i8254_timecounter.tc_frequency = freq;
936	}
937	return (error);
938}
939
940SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW,
941    0, sizeof(u_int), sysctl_machdep_i8254_freq, "IU", "");
942
943static unsigned
944i8254_get_timecount(struct timecounter *tc)
945{
946	u_int count;
947	u_int high, low;
948	u_int eflags;
949
950	eflags = read_eflags();
951	mtx_lock_spin(&clock_lock);
952
953	/* Select timer0 and latch counter value. */
954	outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
955
956	low = inb(TIMER_CNTR0);
957	high = inb(TIMER_CNTR0);
958	count = timer0_max_count - ((high << 8) | low);
959	if (count < i8254_lastcount ||
960	    (!i8254_ticked && (clkintr_pending ||
961	    ((count < 20 || (!(eflags & PSL_I) && count < timer0_max_count / 2u)) &&
962	    i8254_intsrc != NULL &&
963	    i8254_intsrc->is_pic->pic_source_pending(i8254_intsrc))))) {
964		i8254_ticked = 1;
965		i8254_offset += timer0_max_count;
966	}
967	i8254_lastcount = count;
968	count += i8254_offset;
969	mtx_unlock_spin(&clock_lock);
970	return (count);
971}
972
973#ifdef DEV_ISA
974/*
975 * Attach to the ISA PnP descriptors for the timer and realtime clock.
976 */
977static struct isa_pnp_id attimer_ids[] = {
978	{ 0x0001d041 /* PNP0100 */, "AT timer" },
979	{ 0x000bd041 /* PNP0B00 */, "AT realtime clock" },
980	{ 0 }
981};
982
983static int
984attimer_probe(device_t dev)
985{
986	int result;
987
988	if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, attimer_ids)) <= 0)
989		device_quiet(dev);
990	return(result);
991}
992
993static int
994attimer_attach(device_t dev)
995{
996	return(0);
997}
998
999static device_method_t attimer_methods[] = {
1000	/* Device interface */
1001	DEVMETHOD(device_probe,		attimer_probe),
1002	DEVMETHOD(device_attach,	attimer_attach),
1003	DEVMETHOD(device_detach,	bus_generic_detach),
1004	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
1005	DEVMETHOD(device_suspend,	bus_generic_suspend),	/* XXX stop statclock? */
1006	DEVMETHOD(device_resume,	bus_generic_resume),	/* XXX restart statclock? */
1007	{ 0, 0 }
1008};
1009
1010static driver_t attimer_driver = {
1011	"attimer",
1012	attimer_methods,
1013	1,		/* no softc */
1014};
1015
1016static devclass_t attimer_devclass;
1017
1018DRIVER_MODULE(attimer, isa, attimer_driver, attimer_devclass, 0, 0);
1019#endif /* DEV_ISA */
1020