pcrtc.c revision 147754 
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz and Don Ahn.
7 *
8 * 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 147754 2005-07-03 14:19:29Z nyan $
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_apic.h"
52#include "opt_clock.h"
53#include "opt_isa.h"
54#include "opt_mca.h"
55
56#include <sys/param.h>
57#include <sys/systm.h>
58#include <sys/bus.h>
59#include <sys/lock.h>
60#include <sys/kdb.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/limits.h>
67#include <sys/module.h>
68#include <sys/sysctl.h>
69#include <sys/cons.h>
70#include <sys/power.h>
71
72#include <machine/clock.h>
73#include <machine/cputypes.h>
74#include <machine/frame.h>
75#include <machine/intr_machdep.h>
76#include <machine/md_var.h>
77#include <machine/psl.h>
78#ifdef DEV_APIC
79#include <machine/apicvar.h>
80#endif
81#include <machine/specialreg.h>
82#include <machine/ppireg.h>
83#include <machine/timerreg.h>
84
85#include <i386/isa/icu.h>
86#include <pc98/cbus/cbus.h>
87#include <pc98/pc98/pc98_machdep.h>
88#ifdef DEV_ISA
89#include <isa/isavar.h>
90#endif
91
92/*
93 * 32-bit time_t's can't reach leap years before 1904 or after 2036, so we
94 * can use a simple formula for leap years.
95 */
96#define	LEAPYEAR(y) (((u_int)(y) % 4 == 0) ? 1 : 0)
97#define DAYSPERYEAR   (31+28+31+30+31+30+31+31+30+31+30+31)
98
99#define	TIMER_DIV(x) ((timer_freq + (x) / 2) / (x))
100
101int	adjkerntz;		/* local offset from GMT in seconds */
102int	clkintr_pending;
103int	disable_rtc_set;	/* disable resettodr() if != 0 */
104int	pscnt = 1;
105int	psdiv = 1;
106int	statclock_disable;
107#ifndef TIMER_FREQ
108#define TIMER_FREQ   2457600
109#endif
110u_int	timer_freq = TIMER_FREQ;
111int	timer0_max_count;
112int	wall_cmos_clock;	/* wall CMOS clock assumed if != 0 */
113struct mtx clock_lock;
114
115static	int	beeping = 0;
116static	const u_char daysinmonth[] = {31,28,31,30,31,30,31,31,30,31,30,31};
117static	u_int	hardclock_max_count;
118static	struct intsrc *i8254_intsrc;
119static	u_int32_t i8254_lastcount;
120static	u_int32_t i8254_offset;
121static	int	(*i8254_pending)(struct intsrc *);
122static	int	i8254_ticked;
123static	int	using_lapic_timer;
124
125/* Values for timerX_state: */
126#define	RELEASED	0
127#define	RELEASE_PENDING	1
128#define	ACQUIRED	2
129#define	ACQUIRE_PENDING	3
130
131static 	u_char	timer1_state;
132static	u_char	timer2_state;
133static void rtc_serialcombit(int);
134static void rtc_serialcom(int);
135static int rtc_inb(void);
136static void rtc_outb(int);
137
138static	unsigned i8254_get_timecount(struct timecounter *tc);
139static	unsigned i8254_simple_get_timecount(struct timecounter *tc);
140static	void	set_timer_freq(u_int freq, int intr_freq);
141
142static struct timecounter i8254_timecounter = {
143	i8254_get_timecount,	/* get_timecount */
144	0,			/* no poll_pps */
145	~0u,			/* counter_mask */
146	0,			/* frequency */
147	"i8254",		/* name */
148	0			/* quality */
149};
150
151static void
152clkintr(struct clockframe *frame)
153{
154
155	if (timecounter->tc_get_timecount == i8254_get_timecount) {
156		mtx_lock_spin(&clock_lock);
157		if (i8254_ticked)
158			i8254_ticked = 0;
159		else {
160			i8254_offset += timer0_max_count;
161			i8254_lastcount = 0;
162		}
163		clkintr_pending = 0;
164		mtx_unlock_spin(&clock_lock);
165	}
166	if (!using_lapic_timer)
167		hardclock(frame);
168}
169
170int
171acquire_timer1(int mode)
172{
173
174	if (timer1_state != RELEASED)
175		return (-1);
176	timer1_state = ACQUIRED;
177
178	/*
179	 * This access to the timer registers is as atomic as possible
180	 * because it is a single instruction.  We could do better if we
181	 * knew the rate.  Use of splclock() limits glitches to 10-100us,
182	 * and this is probably good enough for timer2, so we aren't as
183	 * careful with it as with timer0.
184	 */
185	outb(TIMER_MODE, TIMER_SEL1 | (mode & 0x3f));
186
187	return (0);
188}
189
190int
191acquire_timer2(int mode)
192{
193
194	if (timer2_state != RELEASED)
195		return (-1);
196	timer2_state = ACQUIRED;
197
198	/*
199	 * This access to the timer registers is as atomic as possible
200	 * because it is a single instruction.  We could do better if we
201	 * knew the rate.  Use of splclock() limits glitches to 10-100us,
202	 * and this is probably good enough for timer2, so we aren't as
203	 * careful with it as with timer0.
204	 */
205	outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f));
206
207	return (0);
208}
209
210int
211release_timer1()
212{
213
214	if (timer1_state != ACQUIRED)
215		return (-1);
216	timer1_state = RELEASED;
217	outb(TIMER_MODE, TIMER_SEL1 | TIMER_SQWAVE | TIMER_16BIT);
218	return (0);
219}
220
221int
222release_timer2()
223{
224
225	if (timer2_state != ACQUIRED)
226		return (-1);
227	timer2_state = RELEASED;
228	outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT);
229	return (0);
230}
231
232
233static int
234getit(void)
235{
236	int high, low;
237
238	mtx_lock_spin(&clock_lock);
239
240	/* Select timer0 and latch counter value. */
241	outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
242
243	low = inb(TIMER_CNTR0);
244	high = inb(TIMER_CNTR0);
245
246	mtx_unlock_spin(&clock_lock);
247	return ((high << 8) | low);
248}
249
250/*
251 * Wait "n" microseconds.
252 * Relies on timer 1 counting down from (timer_freq / hz)
253 * Note: timer had better have been programmed before this is first used!
254 */
255void
256DELAY(int n)
257{
258	int delta, prev_tick, tick, ticks_left;
259
260#ifdef DELAYDEBUG
261	int getit_calls = 1;
262	int n1;
263	static int state = 0;
264
265	if (state == 0) {
266		state = 1;
267		for (n1 = 1; n1 <= 10000000; n1 *= 10)
268			DELAY(n1);
269		state = 2;
270	}
271	if (state == 1)
272		printf("DELAY(%d)...", n);
273#endif
274	/*
275	 * Guard against the timer being uninitialized if we are called
276	 * early for console i/o.
277	 */
278	if (timer0_max_count == 0)
279		set_timer_freq(timer_freq, hz);
280
281	/*
282	 * Read the counter first, so that the rest of the setup overhead is
283	 * counted.  Guess the initial overhead is 20 usec (on most systems it
284	 * takes about 1.5 usec for each of the i/o's in getit().  The loop
285	 * takes about 6 usec on a 486/33 and 13 usec on a 386/20.  The
286	 * multiplications and divisions to scale the count take a while).
287	 *
288	 * However, if ddb is active then use a fake counter since reading
289	 * the i8254 counter involves acquiring a lock.  ddb must not do
290	 * locking for many reasons, but it calls here for at least atkbd
291	 * input.
292	 */
293#ifdef KDB
294	if (kdb_active)
295		prev_tick = 1;
296	else
297#endif
298		prev_tick = getit();
299	n -= 0;			/* XXX actually guess no initial overhead */
300	/*
301	 * Calculate (n * (timer_freq / 1e6)) without using floating point
302	 * and without any avoidable overflows.
303	 */
304	if (n <= 0)
305		ticks_left = 0;
306	else if (n < 256)
307		/*
308		 * Use fixed point to avoid a slow division by 1000000.
309		 * 39099 = 1193182 * 2^15 / 10^6 rounded to nearest.
310		 * 2^15 is the first power of 2 that gives exact results
311		 * for n between 0 and 256.
312		 */
313		ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15;
314	else
315		/*
316		 * Don't bother using fixed point, although gcc-2.7.2
317		 * generates particularly poor code for the long long
318		 * division, since even the slow way will complete long
319		 * before the delay is up (unless we're interrupted).
320		 */
321		ticks_left = ((u_int)n * (long long)timer_freq + 999999)
322			     / 1000000;
323
324	while (ticks_left > 0) {
325#ifdef KDB
326		if (kdb_active) {
327			outb(0x5f, 0);
328			tick = prev_tick - 1;
329			if (tick <= 0)
330				tick = timer0_max_count;
331		} else
332#endif
333			tick = getit();
334#ifdef DELAYDEBUG
335		++getit_calls;
336#endif
337		delta = prev_tick - tick;
338		prev_tick = tick;
339		if (delta < 0) {
340			delta += timer0_max_count;
341			/*
342			 * Guard against timer0_max_count being wrong.
343			 * This shouldn't happen in normal operation,
344			 * but it may happen if set_timer_freq() is
345			 * traced.
346			 */
347			if (delta < 0)
348				delta = 0;
349		}
350		ticks_left -= delta;
351	}
352#ifdef DELAYDEBUG
353	if (state == 1)
354		printf(" %d calls to getit() at %d usec each\n",
355		       getit_calls, (n + 5) / getit_calls);
356#endif
357}
358
359static void
360sysbeepstop(void *chan)
361{
362	ppi_spkr_off();		/* disable counter1 output to speaker */
363	timer_spkr_release();
364	beeping = 0;
365}
366
367int
368sysbeep(int pitch, int period)
369{
370	int x = splclock();
371
372	if (timer_spkr_acquire())
373		if (!beeping) {
374			/* Something else owns it. */
375			splx(x);
376			return (-1); /* XXX Should be EBUSY, but nobody cares anyway. */
377		}
378	disable_intr();
379	spkr_set_pitch(pitch);
380	enable_intr();
381	if (!beeping) {
382		/* enable counter1 output to speaker */
383		ppi_spkr_on();
384		beeping = period;
385		timeout(sysbeepstop, (void *)NULL, period);
386	}
387	splx(x);
388	return (0);
389}
390
391
392unsigned int delaycount;
393#define FIRST_GUESS	0x2000
394static void findcpuspeed(void)
395{
396	int i;
397	int remainder;
398
399	/* Put counter in count down mode */
400	outb(TIMER_MODE, TIMER_SEL0 | TIMER_16BIT | TIMER_RATEGEN);
401	outb(TIMER_CNTR0, 0xff);
402	outb(TIMER_CNTR0, 0xff);
403	for (i = FIRST_GUESS; i; i--)
404		;
405	remainder = getit();
406	delaycount = (FIRST_GUESS * TIMER_DIV(1000)) / (0xffff - remainder);
407}
408
409static u_int
410calibrate_clocks(void)
411{
412	int	timeout;
413	u_int	count, prev_count, tot_count;
414	u_short	sec, start_sec;
415
416	if (bootverbose)
417	        printf("Calibrating clock(s) ... ");
418	/* Check ARTIC. */
419	if (!(PC98_SYSTEM_PARAMETER(0x458) & 0x80) &&
420	    !(PC98_SYSTEM_PARAMETER(0x45b) & 0x04))
421		goto fail;
422	timeout = 100000000;
423
424	/* Read the ARTIC. */
425	sec = inw(0x5e);
426
427	/* Wait for the ARTIC to changes. */
428	start_sec = sec;
429	for (;;) {
430		sec = inw(0x5e);
431		if (sec != start_sec)
432			break;
433		if (--timeout == 0)
434			goto fail;
435	}
436	prev_count = getit();
437	if (prev_count == 0 || prev_count > timer0_max_count)
438		goto fail;
439	tot_count = 0;
440
441	start_sec = sec;
442	for (;;) {
443		sec = inw(0x5e);
444		count = getit();
445		if (count == 0 || count > timer0_max_count)
446			goto fail;
447		if (count > prev_count)
448			tot_count += prev_count - (count - timer0_max_count);
449		else
450			tot_count += prev_count - count;
451		prev_count = count;
452		if ((sec == start_sec + 1200) || /* 1200 = 307.2KHz >> 8 */
453		    (sec < start_sec &&
454		        (u_int)sec + 0x10000 == (u_int)start_sec + 1200))
455			break;
456		if (--timeout == 0)
457			goto fail;
458	}
459
460	if (bootverbose) {
461	        printf("i8254 clock: %u Hz\n", tot_count);
462	}
463	return (tot_count);
464
465fail:
466	if (bootverbose)
467	        printf("failed, using default i8254 clock of %u Hz\n",
468		       timer_freq);
469	return (timer_freq);
470}
471
472static void
473set_timer_freq(u_int freq, int intr_freq)
474{
475	int new_timer0_max_count;
476
477	i8254_timecounter.tc_frequency = freq;
478	mtx_lock_spin(&clock_lock);
479	timer_freq = freq;
480	new_timer0_max_count = hardclock_max_count = TIMER_DIV(intr_freq);
481	if (using_lapic_timer) {
482		outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
483		outb(TIMER_CNTR0, 0);
484		outb(TIMER_CNTR0, 0);
485	} else if (new_timer0_max_count != timer0_max_count) {
486		timer0_max_count = new_timer0_max_count;
487		outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
488		outb(TIMER_CNTR0, timer0_max_count & 0xff);
489		outb(TIMER_CNTR0, timer0_max_count >> 8);
490	}
491	mtx_unlock_spin(&clock_lock);
492}
493
494static void
495i8254_restore(void)
496{
497
498	set_timer_freq(timer_freq, hz);
499}
500
501
502/*
503 * Restore all the timers non-atomically (XXX: should be atomically).
504 *
505 * This function is called from pmtimer_resume() to restore all the timers.
506 * This should not be necessary, but there are broken laptops that do not
507 * restore all the timers on resume.
508 */
509void
510timer_restore(void)
511{
512
513	i8254_restore();		/* restore timer_freq and hz */
514}
515
516/*
517 * Initialize 8254 timer 0 early so that it can be used in DELAY().
518 * XXX initialization of other timers is unintentionally left blank.
519 */
520void
521startrtclock()
522{
523	u_int delta, freq;
524
525	findcpuspeed();
526	if (pc98_machine_type & M_8M)
527		timer_freq = 1996800L; /* 1.9968 MHz */
528	else
529		timer_freq = 2457600L; /* 2.4576 MHz */
530
531	set_timer_freq(timer_freq, hz);
532	freq = calibrate_clocks();
533#ifdef CLK_CALIBRATION_LOOP
534	if (bootverbose) {
535		printf(
536		"Press a key on the console to abort clock calibration\n");
537		while (cncheckc() == -1)
538			calibrate_clocks();
539	}
540#endif
541
542	/*
543	 * Use the calibrated i8254 frequency if it seems reasonable.
544	 * Otherwise use the default, and don't use the calibrated i586
545	 * frequency.
546	 */
547	delta = freq > timer_freq ? freq - timer_freq : timer_freq - freq;
548	if (delta < timer_freq / 100) {
549#ifndef CLK_USE_I8254_CALIBRATION
550		if (bootverbose)
551			printf(
552"CLK_USE_I8254_CALIBRATION not specified - using default frequency\n");
553		freq = timer_freq;
554#endif
555		timer_freq = freq;
556	} else {
557		if (bootverbose)
558			printf(
559		    "%d Hz differs from default of %d Hz by more than 1%%\n",
560			       freq, timer_freq);
561	}
562
563	set_timer_freq(timer_freq, hz);
564	tc_init(&i8254_timecounter);
565
566	init_TSC();
567}
568
569static void
570rtc_serialcombit(int i)
571{
572	outb(IO_RTC, ((i&0x01)<<5)|0x07);
573	DELAY(1);
574	outb(IO_RTC, ((i&0x01)<<5)|0x17);
575	DELAY(1);
576	outb(IO_RTC, ((i&0x01)<<5)|0x07);
577	DELAY(1);
578}
579
580static void
581rtc_serialcom(int i)
582{
583	rtc_serialcombit(i&0x01);
584	rtc_serialcombit((i&0x02)>>1);
585	rtc_serialcombit((i&0x04)>>2);
586	rtc_serialcombit((i&0x08)>>3);
587	outb(IO_RTC, 0x07);
588	DELAY(1);
589	outb(IO_RTC, 0x0f);
590	DELAY(1);
591	outb(IO_RTC, 0x07);
592 	DELAY(1);
593}
594
595static void
596rtc_outb(int val)
597{
598	int s;
599	int sa = 0;
600
601	for (s=0;s<8;s++) {
602	    sa = ((val >> s) & 0x01) ? 0x27 : 0x07;
603	    outb(IO_RTC, sa);		/* set DI & CLK 0 */
604	    DELAY(1);
605	    outb(IO_RTC, sa | 0x10);	/* CLK 1 */
606	    DELAY(1);
607	}
608	outb(IO_RTC, sa & 0xef);	/* CLK 0 */
609}
610
611static int
612rtc_inb(void)
613{
614	int s;
615	int sa = 0;
616
617	for (s=0;s<8;s++) {
618	    sa |= ((inb(0x33) & 0x01) << s);
619	    outb(IO_RTC, 0x17);	/* CLK 1 */
620	    DELAY(1);
621	    outb(IO_RTC, 0x07);	/* CLK 0 */
622	    DELAY(2);
623	}
624	return sa;
625}
626
627/*
628 * Initialize the time of day register, based on the time base which is, e.g.
629 * from a filesystem.
630 */
631void
632inittodr(time_t base)
633{
634	unsigned long	sec, days;
635	int		year, month;
636	int		y, m, s;
637	struct timespec ts;
638	int		second, min, hour;
639
640	if (base) {
641		s = splclock();
642		ts.tv_sec = base;
643		ts.tv_nsec = 0;
644		tc_setclock(&ts);
645		splx(s);
646	}
647
648	rtc_serialcom(0x03);	/* Time Read */
649	rtc_serialcom(0x01);	/* Register shift command. */
650	DELAY(20);
651
652	second = bcd2bin(rtc_inb() & 0xff);	/* sec */
653	min = bcd2bin(rtc_inb() & 0xff);	/* min */
654	hour = bcd2bin(rtc_inb() & 0xff);	/* hour */
655	days = bcd2bin(rtc_inb() & 0xff) - 1;	/* date */
656
657	month = (rtc_inb() >> 4) & 0x0f;	/* month */
658	for (m = 1; m <	month; m++)
659		days +=	daysinmonth[m-1];
660	year = bcd2bin(rtc_inb() & 0xff) + 1900;	/* year */
661	/* 2000 year problem */
662	if (year < 1995)
663		year += 100;
664	if (year < 1970)
665		goto wrong_time;
666	for (y = 1970; y < year; y++)
667		days +=	DAYSPERYEAR + LEAPYEAR(y);
668	if ((month > 2)	&& LEAPYEAR(year))
669		days ++;
670	sec = ((( days * 24 +
671		  hour) * 60 +
672		  min) * 60 +
673		  second);
674	/* sec now contains the	number of seconds, since Jan 1 1970,
675	   in the local	time zone */
676
677	s = splhigh();
678
679	sec += tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
680
681	y = time_second - sec;
682	if (y <= -2 || y >= 2) {
683		/* badly off, adjust it */
684		ts.tv_sec = sec;
685		ts.tv_nsec = 0;
686		tc_setclock(&ts);
687	}
688	splx(s);
689	return;
690
691wrong_time:
692	printf("Invalid time in real time clock.\n");
693	printf("Check and reset the date immediately!\n");
694}
695
696/*
697 * Write system time back to RTC
698 */
699void
700resettodr()
701{
702	unsigned long	tm;
703	int		y, m, s;
704	int		wd;
705
706	if (disable_rtc_set)
707		return;
708
709	s = splclock();
710	tm = time_second;
711	splx(s);
712
713	rtc_serialcom(0x01);	/* Register shift command. */
714
715	/* Calculate local time	to put in RTC */
716
717	tm -= tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
718
719	rtc_outb(bin2bcd(tm%60)); tm /= 60;	/* Write back Seconds */
720	rtc_outb(bin2bcd(tm%60)); tm /= 60;	/* Write back Minutes */
721	rtc_outb(bin2bcd(tm%24)); tm /= 24;	/* Write back Hours   */
722
723	/* We have now the days	since 01-01-1970 in tm */
724	wd = (tm + 4) % 7 + 1;			/* Write back Weekday */
725	for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
726	     tm >= m;
727	     y++,      m = DAYSPERYEAR + LEAPYEAR(y))
728	     tm -= m;
729
730	/* Now we have the years in y and the day-of-the-year in tm */
731	for (m = 0; ; m++) {
732		int ml;
733
734		ml = daysinmonth[m];
735		if (m == 1 && LEAPYEAR(y))
736			ml++;
737		if (tm < ml)
738			break;
739		tm -= ml;
740	}
741
742	m++;
743	rtc_outb(bin2bcd(tm+1));		/* Write back Day     */
744	rtc_outb((m << 4) | wd);		/* Write back Month & Weekday  */
745	rtc_outb(bin2bcd(y%100));		/* Write back Year    */
746
747	rtc_serialcom(0x02);	/* Time set & Counter hold command. */
748	rtc_serialcom(0x00);	/* Register hold command. */
749}
750
751
752/*
753 * Start both clocks running.
754 */
755void
756cpu_initclocks()
757{
758
759#ifdef DEV_APIC
760	using_lapic_timer = lapic_setup_clock();
761#endif
762	/*
763	 * If we aren't using the local APIC timer to drive the kernel
764	 * clocks, setup the interrupt handler for the 8254 timer 0 so
765	 * that it can drive hardclock().  Otherwise, change the 8254
766	 * timecounter to user a simpler algorithm.
767	 */
768	if (!using_lapic_timer || 1) {
769		intr_add_handler("clk", 0, (driver_intr_t *)clkintr, NULL,
770		    INTR_TYPE_CLK | INTR_FAST, NULL);
771		i8254_intsrc = intr_lookup_source(0);
772		if (i8254_intsrc != NULL)
773			i8254_pending =
774			    i8254_intsrc->is_pic->pic_source_pending;
775	} else {
776		i8254_timecounter.tc_get_timecount =
777		    i8254_simple_get_timecount;
778		i8254_timecounter.tc_counter_mask = 0xffff;
779		set_timer_freq(timer_freq, hz);
780	}
781
782	init_TSC_tc();
783}
784
785void
786cpu_startprofclock(void)
787{
788}
789
790void
791cpu_stopprofclock(void)
792{
793}
794
795static int
796sysctl_machdep_i8254_freq(SYSCTL_HANDLER_ARGS)
797{
798	int error;
799	u_int freq;
800
801	/*
802	 * Use `i8254' instead of `timer' in external names because `timer'
803	 * is is too generic.  Should use it everywhere.
804	 */
805	freq = timer_freq;
806	error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
807	if (error == 0 && req->newptr != NULL)
808		set_timer_freq(freq, hz);
809	return (error);
810}
811
812SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW,
813    0, sizeof(u_int), sysctl_machdep_i8254_freq, "IU", "");
814
815static unsigned
816i8254_simple_get_timecount(struct timecounter *tc)
817{
818	u_int count;
819	u_int high, low;
820
821	mtx_lock_spin(&clock_lock);
822
823	/* Select timer0 and latch counter value. */
824	outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
825
826	low = inb(TIMER_CNTR0);
827	high = inb(TIMER_CNTR0);
828	count = 0xffff - ((high << 8) | low);
829	mtx_unlock_spin(&clock_lock);
830	return (count);
831}
832
833static unsigned
834i8254_get_timecount(struct timecounter *tc)
835{
836	u_int count;
837	u_int high, low;
838	u_int eflags;
839
840	eflags = read_eflags();
841	mtx_lock_spin(&clock_lock);
842
843	/* Select timer0 and latch counter value. */
844	outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
845
846	low = inb(TIMER_CNTR0);
847	high = inb(TIMER_CNTR0);
848	count = timer0_max_count - ((high << 8) | low);
849	if (count < i8254_lastcount ||
850	    (!i8254_ticked && (clkintr_pending ||
851	    ((count < 20 || (!(eflags & PSL_I) && count < timer0_max_count / 2u)) &&
852	    i8254_pending != NULL && i8254_pending(i8254_intsrc))))) {
853		i8254_ticked = 1;
854		i8254_offset += timer0_max_count;
855	}
856	i8254_lastcount = count;
857	count += i8254_offset;
858	mtx_unlock_spin(&clock_lock);
859	return (count);
860}
861
862#ifdef DEV_ISA
863/*
864 * Attach to the ISA PnP descriptors for the timer and realtime clock.
865 */
866static struct isa_pnp_id attimer_ids[] = {
867	{ 0x0001d041 /* PNP0100 */, "AT timer" },
868	{ 0x000bd041 /* PNP0B00 */, "AT realtime clock" },
869	{ 0 }
870};
871
872static int
873attimer_probe(device_t dev)
874{
875	int result;
876
877	if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, attimer_ids)) <= 0)
878		device_quiet(dev);
879	return(result);
880}
881
882static int
883attimer_attach(device_t dev)
884{
885	return(0);
886}
887
888static device_method_t attimer_methods[] = {
889	/* Device interface */
890	DEVMETHOD(device_probe,		attimer_probe),
891	DEVMETHOD(device_attach,	attimer_attach),
892	DEVMETHOD(device_detach,	bus_generic_detach),
893	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
894	DEVMETHOD(device_suspend,	bus_generic_suspend),	/* XXX stop statclock? */
895	DEVMETHOD(device_resume,	bus_generic_resume),	/* XXX restart statclock? */
896	{ 0, 0 }
897};
898
899static driver_t attimer_driver = {
900	"attimer",
901	attimer_methods,
902	1,		/* no softc */
903};
904
905static devclass_t attimer_devclass;
906
907DRIVER_MODULE(attimer, isa, attimer_driver, attimer_devclass, 0, 0);
908#endif /* DEV_ISA */
909