pcrtc.c revision 19269
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 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 *	from: @(#)clock.c	7.2 (Berkeley) 5/12/91
37 *	$Id: clock.c,v 1.9 1996/10/29 08:36:19 asami Exp $
38 */
39
40/*
41 * Routines to handle clock hardware.
42 */
43
44/*
45 * inittodr, settodr and support routines written
46 * by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>
47 *
48 * reintroduced and updated by Chris Stenton <chris@gnome.co.uk> 8/10/94
49 */
50
51/*
52 * modified for PC98 by Kakefuda
53 */
54
55#include "opt_clock.h"
56#include "opt_cpu.h"
57
58#include <sys/param.h>
59#include <sys/systm.h>
60#include <sys/time.h>
61#include <sys/kernel.h>
62#include <sys/sysctl.h>
63
64#include <machine/clock.h>
65#ifdef CLK_CALIBRATION_LOOP
66#include <machine/cons.h>
67#endif
68#include <machine/cpu.h>
69#include <machine/frame.h>
70
71#include <i386/isa/icu.h>
72#ifdef PC98
73#include <pc98/pc98/pc98.h>
74#include <i386/isa/isa_device.h>
75#else
76#include <i386/isa/isa.h>
77#include <i386/isa/isa_device.h>
78#include <i386/isa/rtc.h>
79#endif
80#include <i386/isa/timerreg.h>
81
82/*
83 * 32-bit time_t's can't reach leap years before 1904 or after 2036, so we
84 * can use a simple formula for leap years.
85 */
86#define	LEAPYEAR(y) ((u_int)(y) % 4 == 0)
87#define DAYSPERYEAR   (31+28+31+30+31+30+31+31+30+31+30+31)
88
89#define	TIMER_DIV(x) ((timer_freq + (x) / 2) / (x))
90
91/*
92 * Time in timer cycles that it takes for microtime() to disable interrupts
93 * and latch the count.  microtime() currently uses "cli; outb ..." so it
94 * normally takes less than 2 timer cycles.  Add a few for cache misses.
95 * Add a few more to allow for latency in bogus calls to microtime() with
96 * interrupts already disabled.
97 */
98#define	TIMER0_LATCH_COUNT	20
99
100/*
101 * Maximum frequency that we are willing to allow for timer0.  Must be
102 * low enough to guarantee that the timer interrupt handler returns
103 * before the next timer interrupt.  Must result in a lower TIMER_DIV
104 * value than TIMER0_LATCH_COUNT so that we don't have to worry about
105 * underflow in the calculation of timer0_overflow_threshold.
106 */
107#define	TIMER0_MAX_FREQ		20000
108
109int	adjkerntz;		/* local offset	from GMT in seconds */
110int	disable_rtc_set;	/* disable resettodr() if != 0 */
111u_int	idelayed;
112#if defined(I586_CPU) || defined(I686_CPU)
113u_int	i586_ctr_bias;
114u_int	i586_ctr_comultiplier;
115u_int	i586_ctr_freq;
116u_int	i586_ctr_multiplier;
117#endif
118int	statclock_disable;
119u_int	stat_imask = SWI_CLOCK_MASK;
120#ifdef TIMER_FREQ
121u_int	timer_freq = TIMER_FREQ;
122#else
123#ifdef PC98
124#ifndef AUTO_CLOCK
125#ifndef PC98_8M
126u_int	timer_freq = 2457600;
127#else	/* !PC98_8M */
128u_int	timer_freq = 1996800;
129#endif	/* PC98_8M */
130#else	/* AUTO_CLOCK */
131u_int	timer_freq = 2457600;
132#endif	/* AUTO_CLOCK */
133#else /* IBM-PC */
134u_int	timer_freq = 1193182;
135#endif /* PC98 */
136#endif
137int	timer0_max_count;
138u_int	timer0_overflow_threshold;
139u_int	timer0_prescaler_count;
140int	wall_cmos_clock;	/* wall	CMOS clock assumed if != 0 */
141
142static	int	beeping = 0;
143static	u_int	clk_imask = HWI_MASK | SWI_MASK;
144static	const u_char daysinmonth[] = {31,28,31,30,31,30,31,31,30,31,30,31};
145static	u_int	hardclock_max_count;
146/*
147 * XXX new_function and timer_func should not handle clockframes, but
148 * timer_func currently needs to hold hardclock to handle the
149 * timer0_state == 0 case.  We should use register_intr()/unregister_intr()
150 * to switch between clkintr() and a slightly different timerintr().
151 */
152static	void	(*new_function) __P((struct clockframe *frame));
153static	u_int	new_rate;
154#ifndef PC98
155static	u_char	rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
156static	u_char	rtc_statusb = RTCSB_24HR | RTCSB_PINTR;
157#endif
158
159/* Values for timerX_state: */
160#define	RELEASED	0
161#define	RELEASE_PENDING	1
162#define	ACQUIRED	2
163#define	ACQUIRE_PENDING	3
164
165static 	u_char	timer0_state;
166#ifdef	PC98
167static 	u_char	timer1_state;
168#endif
169static	u_char	timer2_state;
170static	void	(*timer_func) __P((struct clockframe *frame)) = hardclock;
171int		rtc_inb __P((void));
172
173#if defined(I586_CPU) || defined(I686_CPU)
174static	void	set_i586_ctr_freq(u_int i586_freq, u_int i8254_freq);
175#endif
176
177static void
178clkintr(struct clockframe frame)
179{
180	timer_func(&frame);
181	switch (timer0_state) {
182
183	case RELEASED:
184		setdelayed();
185		break;
186
187	case ACQUIRED:
188		if ((timer0_prescaler_count += timer0_max_count)
189		    >= hardclock_max_count) {
190			hardclock(&frame);
191			setdelayed();
192			timer0_prescaler_count -= hardclock_max_count;
193		}
194		break;
195
196	case ACQUIRE_PENDING:
197		setdelayed();
198		timer0_max_count = TIMER_DIV(new_rate);
199		timer0_overflow_threshold =
200			timer0_max_count - TIMER0_LATCH_COUNT;
201		disable_intr();
202		outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
203		outb(TIMER_CNTR0, timer0_max_count & 0xff);
204		outb(TIMER_CNTR0, timer0_max_count >> 8);
205		enable_intr();
206		timer0_prescaler_count = 0;
207		timer_func = new_function;
208		timer0_state = ACQUIRED;
209		break;
210
211	case RELEASE_PENDING:
212		if ((timer0_prescaler_count += timer0_max_count)
213		    >= hardclock_max_count) {
214			hardclock(&frame);
215			setdelayed();
216			timer0_max_count = hardclock_max_count;
217			timer0_overflow_threshold =
218				timer0_max_count - TIMER0_LATCH_COUNT;
219			disable_intr();
220			outb(TIMER_MODE,
221			     TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
222			outb(TIMER_CNTR0, timer0_max_count & 0xff);
223			outb(TIMER_CNTR0, timer0_max_count >> 8);
224			enable_intr();
225			/*
226			 * See microtime.s for this magic.
227			 */
228#ifdef PC98
229#ifndef AUTO_CLOCK
230#ifndef PC98_8M
231			time.tv_usec += (6667 *
232				(timer0_prescaler_count - hardclock_max_count))
233				>> 14;
234#else /* PC98_8M */
235			time.tv_usec += (16411 *
236				(timer0_prescaler_count - hardclock_max_count))
237				>> 15;
238#endif /* PC98_8M */
239#else /* AUTO_CLOCK */
240			if (pc98_machine_type & M_8M) {
241				/* PC98_8M */
242				time.tv_usec += (16411 *
243					(timer0_prescaler_count -
244					 hardclock_max_count)) >> 15;
245			} else {
246				time.tv_usec += (6667 *
247					(timer0_prescaler_count -
248					 hardclock_max_count)) >> 14;
249			}
250#endif /* AUTO_CLOCK */
251#else /* IBM-PC */
252			time.tv_usec += (27465 *
253				(timer0_prescaler_count - hardclock_max_count))
254				>> 15;
255#endif /* PC98 */
256			if (time.tv_usec >= 1000000)
257				time.tv_usec -= 1000000;
258			timer0_prescaler_count = 0;
259			timer_func = hardclock;
260			timer0_state = RELEASED;
261		}
262		break;
263	}
264}
265
266/*
267 * The acquire and release functions must be called at ipl >= splclock().
268 */
269int
270acquire_timer0(int rate, void (*function) __P((struct clockframe *frame)))
271{
272	static int old_rate;
273
274	if (rate <= 0 || rate > TIMER0_MAX_FREQ)
275		return (-1);
276	switch (timer0_state) {
277
278	case RELEASED:
279		timer0_state = ACQUIRE_PENDING;
280		break;
281
282	case RELEASE_PENDING:
283		if (rate != old_rate)
284			return (-1);
285		/*
286		 * The timer has been released recently, but is being
287		 * re-acquired before the release completed.  In this
288		 * case, we simply reclaim it as if it had not been
289		 * released at all.
290		 */
291		timer0_state = ACQUIRED;
292		break;
293
294	default:
295		return (-1);	/* busy */
296	}
297	new_function = function;
298	old_rate = new_rate = rate;
299	return (0);
300}
301
302#ifdef PC98
303int
304acquire_timer1(int mode)
305{
306
307	if (timer1_state != RELEASED)
308		return (-1);
309	timer1_state = ACQUIRED;
310
311	/*
312	 * This access to the timer registers is as atomic as possible
313	 * because it is a single instruction.  We could do better if we
314	 * knew the rate.  Use of splclock() limits glitches to 10-100us,
315	 * and this is probably good enough for timer2, so we aren't as
316	 * careful with it as with timer0.
317	 */
318	outb(TIMER_MODE, TIMER_SEL1 | (mode & 0x3f));
319
320	return (0);
321}
322#endif
323
324int
325acquire_timer2(int mode)
326{
327
328	if (timer2_state != RELEASED)
329		return (-1);
330	timer2_state = ACQUIRED;
331
332	/*
333	 * This access to the timer registers is as atomic as possible
334	 * because it is a single instruction.  We could do better if we
335	 * knew the rate.  Use of splclock() limits glitches to 10-100us,
336	 * and this is probably good enough for timer2, so we aren't as
337	 * careful with it as with timer0.
338	 */
339	outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f));
340
341	return (0);
342}
343
344int
345release_timer0()
346{
347	switch (timer0_state) {
348
349	case ACQUIRED:
350		timer0_state = RELEASE_PENDING;
351		break;
352
353	case ACQUIRE_PENDING:
354		/* Nothing happened yet, release quickly. */
355		timer0_state = RELEASED;
356		break;
357
358	default:
359		return (-1);
360	}
361	return (0);
362}
363
364#ifdef PC98
365int
366release_timer1()
367{
368
369	if (timer1_state != ACQUIRED)
370		return (-1);
371	timer1_state = RELEASED;
372	outb(TIMER_MODE, TIMER_SEL1 | TIMER_SQWAVE | TIMER_16BIT);
373	return (0);
374}
375#endif
376
377int
378release_timer2()
379{
380
381	if (timer2_state != ACQUIRED)
382		return (-1);
383	timer2_state = RELEASED;
384	outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT);
385	return (0);
386}
387
388#ifndef PC98
389/*
390 * This routine receives statistical clock interrupts from the RTC.
391 * As explained above, these occur at 128 interrupts per second.
392 * When profiling, we receive interrupts at a rate of 1024 Hz.
393 *
394 * This does not actually add as much overhead as it sounds, because
395 * when the statistical clock is active, the hardclock driver no longer
396 * needs to keep (inaccurate) statistics on its own.  This decouples
397 * statistics gathering from scheduling interrupts.
398 *
399 * The RTC chip requires that we read status register C (RTC_INTR)
400 * to acknowledge an interrupt, before it will generate the next one.
401 */
402static void
403rtcintr(struct clockframe frame)
404{
405	u_char stat;
406	stat = rtcin(RTC_INTR);
407	if(stat & RTCIR_PERIOD) {
408		statclock(&frame);
409	}
410}
411
412#include "opt_ddb.h"
413#ifdef DDB
414#include <ddb/ddb.h>
415
416DB_SHOW_COMMAND(rtc, rtc)
417{
418	printf("%02x/%02x/%02x %02x:%02x:%02x, A = %02x, B = %02x, C = %02x\n",
419	       rtcin(RTC_YEAR), rtcin(RTC_MONTH), rtcin(RTC_DAY),
420	       rtcin(RTC_HRS), rtcin(RTC_MIN), rtcin(RTC_SEC),
421	       rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR));
422}
423#endif /* DDB */
424#endif /* for PC98 */
425
426static int
427getit(void)
428{
429	u_long ef;
430	int high, low;
431
432	ef = read_eflags();
433	disable_intr();
434
435	/* Select timer0 and latch counter value. */
436	outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
437
438	low = inb(TIMER_CNTR0);
439	high = inb(TIMER_CNTR0);
440
441	write_eflags(ef);
442	return ((high << 8) | low);
443}
444
445/*
446 * Wait "n" microseconds.
447 * Relies on timer 1 counting down from (timer_freq / hz)
448 * Note: timer had better have been programmed before this is first used!
449 */
450void
451DELAY(int n)
452{
453	int prev_tick, tick, ticks_left, sec, usec;
454
455#ifdef DELAYDEBUG
456	int getit_calls = 1;
457	int n1;
458	static int state = 0;
459
460	if (state == 0) {
461		state = 1;
462		for (n1 = 1; n1 <= 10000000; n1 *= 10)
463			DELAY(n1);
464		state = 2;
465	}
466	if (state == 1)
467		printf("DELAY(%d)...", n);
468#endif
469	/*
470	 * Read the counter first, so that the rest of the setup overhead is
471	 * counted.  Guess the initial overhead is 20 usec (on most systems it
472	 * takes about 1.5 usec for each of the i/o's in getit().  The loop
473	 * takes about 6 usec on a 486/33 and 13 usec on a 386/20.  The
474	 * multiplications and divisions to scale the count take a while).
475	 */
476	prev_tick = getit();
477	n -= 20;
478	/*
479	 * Calculate (n * (timer_freq / 1e6)) without using floating point
480	 * and without any avoidable overflows.
481	 */
482	sec = n / 1000000;
483	usec = n - sec * 1000000;
484	ticks_left = sec * timer_freq
485		     + usec * (timer_freq / 1000000)
486		     + usec * ((timer_freq % 1000000) / 1000) / 1000
487		     + usec * (timer_freq % 1000) / 1000000;
488	if (n < 0)
489		ticks_left = 0;	/* XXX timer_freq is unsigned */
490
491	while (ticks_left > 0) {
492		tick = getit();
493#ifdef DELAYDEBUG
494		++getit_calls;
495#endif
496		if (tick > prev_tick)
497			ticks_left -= prev_tick - (tick - timer0_max_count);
498		else
499			ticks_left -= prev_tick - tick;
500		prev_tick = tick;
501	}
502#ifdef DELAYDEBUG
503	if (state == 1)
504		printf(" %d calls to getit() at %d usec each\n",
505		       getit_calls, (n + 5) / getit_calls);
506#endif
507}
508
509static void
510sysbeepstop(void *chan)
511{
512#ifdef PC98	/* PC98 */
513	outb(IO_PPI, inb(IO_PPI)|0x08);	/* disable counter1 output to speaker */
514	release_timer1();
515#else
516	outb(IO_PPI, inb(IO_PPI)&0xFC);	/* disable counter2 output to speaker */
517	release_timer2();
518#endif
519	beeping = 0;
520}
521
522int
523sysbeep(int pitch, int period)
524{
525	int x = splclock();
526
527#ifdef PC98
528	if (acquire_timer1(TIMER_SQWAVE|TIMER_16BIT))
529		if (!beeping) {
530			/* Something else owns it. */
531			splx(x);
532			return (-1); /* XXX Should be EBUSY, but nobody cares anyway. */
533		}
534	disable_intr();
535	outb(0x3fdb, pitch);
536	outb(0x3fdb, (pitch>>8));
537	enable_intr();
538	if (!beeping) {
539		/* enable counter1 output to speaker */
540		outb(IO_PPI, (inb(IO_PPI) & 0xf7));
541		beeping = period;
542		timeout(sysbeepstop, (void *)NULL, period);
543	}
544#else
545	if (acquire_timer2(TIMER_SQWAVE|TIMER_16BIT))
546		if (!beeping) {
547			/* Something else owns it. */
548			splx(x);
549			return (-1); /* XXX Should be EBUSY, but nobody cares anyway. */
550		}
551	disable_intr();
552	outb(TIMER_CNTR2, pitch);
553	outb(TIMER_CNTR2, (pitch>>8));
554	enable_intr();
555	if (!beeping) {
556		/* enable counter2 output to speaker */
557		outb(IO_PPI, inb(IO_PPI) | 3);
558		beeping = period;
559		timeout(sysbeepstop, (void *)NULL, period);
560	}
561#endif
562	splx(x);
563	return (0);
564}
565
566#ifndef PC98
567/*
568 * RTC support routines
569 */
570
571int
572rtcin(reg)
573	int reg;
574{
575	u_char val;
576
577	outb(IO_RTC, reg);
578	inb(0x84);
579	val = inb(IO_RTC + 1);
580	inb(0x84);
581	return (val);
582}
583
584static __inline void
585writertc(u_char reg, u_char val)
586{
587	outb(IO_RTC, reg);
588	outb(IO_RTC + 1, val);
589}
590
591static __inline int
592readrtc(int port)
593{
594	return(bcd2bin(rtcin(port)));
595}
596#endif
597
598#ifdef PC98
599unsigned int delaycount;
600#define FIRST_GUESS	0x2000
601static void findcpuspeed(void)
602{
603	int i;
604	int remainder;
605
606	/* Put counter in count down mode */
607	outb(TIMER_MODE, TIMER_SEL0 | TIMER_16BIT | TIMER_RATEGEN);
608	outb(TIMER_CNTR0, 0xff);
609	outb(TIMER_CNTR0, 0xff);
610	for (i = FIRST_GUESS; i; i--)
611		;
612	remainder = getit();
613	delaycount = (FIRST_GUESS * TIMER_DIV(1000)) / (0xffff - remainder);
614}
615#endif
616
617#ifndef PC98
618static u_int
619calibrate_clocks(void)
620{
621	u_int count, prev_count, tot_count;
622	int sec, start_sec, timeout;
623
624	printf("Calibrating clock(s) relative to mc146818A clock ... ");
625	if (!(rtcin(RTC_STATUSD) & RTCSD_PWR))
626		goto fail;
627	timeout = 100000000;
628
629	/* Read the mc146818A seconds counter. */
630	for (;;) {
631		if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) {
632			sec = rtcin(RTC_SEC);
633			break;
634		}
635		if (--timeout == 0)
636			goto fail;
637	}
638
639	/* Wait for the mC146818A seconds counter to change. */
640	start_sec = sec;
641	for (;;) {
642		if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) {
643			sec = rtcin(RTC_SEC);
644			if (sec != start_sec)
645				break;
646		}
647		if (--timeout == 0)
648			goto fail;
649	}
650
651	/* Start keeping track of the i8254 counter. */
652	prev_count = getit();
653	if (prev_count == 0 || prev_count > timer0_max_count)
654		goto fail;
655	tot_count = 0;
656
657#if defined(I586_CPU) || defined(I686_CPU)
658	if (cpu_class == CPUCLASS_586 || cpu_class == CPUCLASS_686)
659		wrmsr(0x10, 0LL);	/* XXX 0x10 is the MSR for the TSC */
660#endif
661
662	/*
663	 * Wait for the mc146818A seconds counter to change.  Read the i8254
664	 * counter for each iteration since this is convenient and only
665	 * costs a few usec of inaccuracy. The timing of the final reads
666	 * of the counters almost matches the timing of the initial reads,
667	 * so the main cause of inaccuracy is the varying latency from
668	 * inside getit() or rtcin(RTC_STATUSA) to the beginning of the
669	 * rtcin(RTC_SEC) that returns a changed seconds count.  The
670	 * maximum inaccuracy from this cause is < 10 usec on 486's.
671	 */
672	start_sec = sec;
673	for (;;) {
674		if (!(rtcin(RTC_STATUSA) & RTCSA_TUP))
675			sec = rtcin(RTC_SEC);
676		count = getit();
677		if (count == 0 || count > timer0_max_count)
678			goto fail;
679		if (count > prev_count)
680			tot_count += prev_count - (count - timer0_max_count);
681		else
682			tot_count += prev_count - count;
683		prev_count = count;
684		if (sec != start_sec)
685			break;
686		if (--timeout == 0)
687			goto fail;
688	}
689
690#if defined(I586_CPU) || defined(I686_CPU)
691	/*
692	 * Read the cpu cycle counter.  The timing considerations are
693	 * similar to those for the i8254 clock.
694	 */
695	if (cpu_class == CPUCLASS_586 || cpu_class == CPUCLASS_686) {
696		set_i586_ctr_freq((u_int)rdtsc(), tot_count);
697		printf("i586 clock: %u Hz, ", i586_ctr_freq);
698	}
699#endif
700
701	printf("i8254 clock: %u Hz\n", tot_count);
702	return (tot_count);
703
704fail:
705	printf("failed, using default i8254 clock of %u Hz\n", timer_freq);
706	return (timer_freq);
707}
708#endif	/* !PC98 */
709
710static void
711set_timer_freq(u_int freq, int intr_freq)
712{
713	u_long ef;
714
715	ef = read_eflags();
716	disable_intr();
717	timer_freq = freq;
718	timer0_max_count = hardclock_max_count = TIMER_DIV(intr_freq);
719	timer0_overflow_threshold = timer0_max_count - TIMER0_LATCH_COUNT;
720	outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
721	outb(TIMER_CNTR0, timer0_max_count & 0xff);
722	outb(TIMER_CNTR0, timer0_max_count >> 8);
723	write_eflags(ef);
724}
725
726/*
727 * Initialize 8253 timer 0 early so that it can be used in DELAY().
728 * XXX initialization of other timers is unintentionally left blank.
729 */
730void
731startrtclock()
732{
733	u_int delta, freq;
734
735#ifdef PC98
736	findcpuspeed();
737#ifndef AUTO_CLOCK
738	if (pc98_machine_type & M_8M) {
739#ifndef	PC98_8M
740		printf("you must reconfig a kernel with \"PC98_8M\" option.\n");
741#endif
742	} else {
743#ifdef	PC98_8M
744		printf("You must reconfig a kernel without \"PC98_8M\" option.\n");
745#endif
746	}
747#else /* AUTO_CLOCK */
748	if (pc98_machine_type & M_8M)
749		timer_freq = 1996800L; /* 1.9968 MHz */
750	else
751		timer_freq = 2457600L; /* 2.4576 MHz */
752#endif /* AUTO_CLOCK */
753#endif /* PC98 */
754
755#ifndef PC98
756	writertc(RTC_STATUSA, rtc_statusa);
757	writertc(RTC_STATUSB, RTCSB_24HR);
758#endif
759
760#ifndef PC98
761	set_timer_freq(timer_freq, hz);
762	freq = calibrate_clocks();
763#ifdef CLK_CALIBRATION_LOOP
764	if (bootverbose) {
765		printf(
766		"Press a key on the console to abort clock calibration\n");
767		while (cncheckc() == -1)
768			calibrate_clocks();
769	}
770#endif
771
772	/*
773	 * Use the calibrated i8254 frequency if it seems reasonable.
774	 * Otherwise use the default, and don't use the calibrated i586
775	 * frequency.
776	 */
777	delta = freq > timer_freq ? freq - timer_freq : timer_freq - freq;
778	if (delta < timer_freq / 100) {
779#ifndef CLK_USE_I8254_CALIBRATION
780		if (bootverbose)
781			printf(
782"CLK_USE_I8254_CALIBRATION not specified - using default frequency\n");
783		freq = timer_freq;
784#endif
785		timer_freq = freq;
786	} else {
787		printf("%d Hz differs from default of %d Hz by more than 1%%\n",
788		       freq, timer_freq);
789#if defined(I586_CPU) || defined(I686_CPU)
790		i586_ctr_freq = 0;
791#endif
792	}
793#endif
794
795	set_timer_freq(timer_freq, hz);
796
797#if defined(I586_CPU) || defined(I686_CPU)
798#ifndef CLK_USE_I586_CALIBRATION
799	if (i586_ctr_freq != 0) {
800		if (bootverbose)
801			printf(
802"CLK_USE_I586_CALIBRATION not specified - using old calibration method\n");
803		i586_ctr_freq = 0;
804	}
805#endif
806	if (i586_ctr_freq == 0 &&
807	    (cpu_class == CPUCLASS_586 || cpu_class == CPUCLASS_686)) {
808		/*
809		 * Calibration of the i586 clock relative to the mc146818A
810		 * clock failed.  Do a less accurate calibration relative
811		 * to the i8254 clock.
812		 */
813		wrmsr(0x10, 0LL);	/* XXX */
814		DELAY(1000000);
815		set_i586_ctr_freq((u_int)rdtsc(), timer_freq);
816#ifdef CLK_USE_I586_CALIBRATION
817		printf("i586 clock: %u Hz\n", i586_ctr_freq);
818#endif
819	}
820#endif
821}
822
823#ifdef PC98
824void
825rtc_serialcombit(int i)
826{
827	outb(IO_RTC, ((i&0x01)<<5)|0x07);
828	DELAY(1);
829	outb(IO_RTC, ((i&0x01)<<5)|0x17);
830	DELAY(1);
831	outb(IO_RTC, ((i&0x01)<<5)|0x07);
832	DELAY(1);
833}
834
835void
836rtc_serialcom(int i)
837{
838	rtc_serialcombit(i&0x01);
839	rtc_serialcombit((i&0x02)>>1);
840	rtc_serialcombit((i&0x04)>>2);
841	rtc_serialcombit((i&0x08)>>3);
842	outb(IO_RTC, 0x07);
843	DELAY(1);
844	outb(IO_RTC, 0x0f);
845	DELAY(1);
846	outb(IO_RTC, 0x07);
847 	DELAY(1);
848}
849
850void
851rtc_outb(int val)
852{
853	int s;
854	int sa = 0;
855
856	for (s=0;s<8;s++) {
857	    sa = ((val >> s) & 0x01) ? 0x27 : 0x07;
858	    outb(IO_RTC, sa);		/* set DI & CLK 0 */
859	    DELAY(1);
860	    outb(IO_RTC, sa | 0x10);	/* CLK 1 */
861	    DELAY(1);
862	}
863	outb(IO_RTC, sa & 0xef);	/* CLK 0 */
864}
865
866int
867rtc_inb(void)
868{
869	int s;
870	int sa = 0;
871
872	for (s=0;s<8;s++) {
873	    sa |= ((inb(0x33) & 0x01) << s);
874	    outb(IO_RTC, 0x17);	/* CLK 1 */
875	    DELAY(1);
876	    outb(IO_RTC, 0x07);	/* CLK 0 */
877	    DELAY(2);
878	}
879	return sa;
880}
881#endif /* PC-98 */
882
883/*
884 * Initialize the time of day register,	based on the time base which is, e.g.
885 * from	a filesystem.
886 */
887void
888inittodr(time_t base)
889{
890	unsigned long	sec, days;
891	int		yd;
892	int		year, month;
893	int		y, m, s;
894#ifdef PC98
895	int		second, min, hour;
896#endif
897
898	s = splclock();
899	time.tv_sec  = base;
900	time.tv_usec = 0;
901	splx(s);
902
903#ifdef PC98
904	rtc_serialcom(0x03);	/* Time Read */
905	rtc_serialcom(0x01);	/* Register shift command. */
906	DELAY(20);
907
908	second = bcd2bin(rtc_inb() & 0xff);	/* sec */
909	min = bcd2bin(rtc_inb() & 0xff);	/* min */
910	hour = bcd2bin(rtc_inb() & 0xff);	/* hour */
911	days = bcd2bin(rtc_inb() & 0xff) - 1;	/* date */
912
913	month = (rtc_inb() >> 4) & 0x0f;	/* month */
914	for (m = 1; m <	month; m++)
915		days +=	daysinmonth[m-1];
916	year = bcd2bin(rtc_inb() & 0xff) + 1900;	/* year */
917	/* 2000 year problem */
918	if (year < 1995)
919		year += 100;
920	if (year < 1970)
921		goto wrong_time;
922	for (y = 1970; y < year; y++)
923		days +=	DAYSPERYEAR + LEAPYEAR(y);
924	if ((month > 2)	&& LEAPYEAR(year))
925		days ++;
926	sec = ((( days * 24 +
927		  hour) * 60 +
928		  min) * 60 +
929		  second);
930	/* sec now contains the	number of seconds, since Jan 1 1970,
931	   in the local	time zone */
932#else	/* IBM-PC */
933	/* Look	if we have a RTC present and the time is valid */
934	if (!(rtcin(RTC_STATUSD) & RTCSD_PWR))
935		goto wrong_time;
936
937	/* wait	for time update	to complete */
938	/* If RTCSA_TUP	is zero, we have at least 244us	before next update */
939	while (rtcin(RTC_STATUSA) & RTCSA_TUP);
940
941	days = 0;
942#ifdef USE_RTC_CENTURY
943	year = readrtc(RTC_YEAR) + readrtc(RTC_CENTURY)	* 100;
944#else
945	year = readrtc(RTC_YEAR) + 1900;
946	if (year < 1970)
947		year += 100;
948#endif
949	if (year < 1970)
950		goto wrong_time;
951	month =	readrtc(RTC_MONTH);
952	for (m = 1; m <	month; m++)
953		days +=	daysinmonth[m-1];
954	if ((month > 2)	&& LEAPYEAR(year))
955		days ++;
956	days +=	readrtc(RTC_DAY) - 1;
957	yd = days;
958	for (y = 1970; y < year; y++)
959		days +=	DAYSPERYEAR + LEAPYEAR(y);
960	sec = ((( days * 24 +
961		  readrtc(RTC_HRS)) * 60 +
962		  readrtc(RTC_MIN)) * 60 +
963		  readrtc(RTC_SEC));
964	/* sec now contains the	number of seconds, since Jan 1 1970,
965	   in the local	time zone */
966#endif
967
968	sec += tz.tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
969
970	s = splclock();
971	time.tv_sec = sec;
972	splx(s);
973	return;
974
975wrong_time:
976	printf("Invalid	time in	real time clock.\n");
977	printf("Check and reset	the date immediately!\n");
978}
979
980/*
981 * Write system	time back to RTC
982 */
983void
984resettodr()
985{
986	unsigned long	tm;
987	int		y, m, s;
988#ifdef PC98
989	int		wd;
990#endif
991
992	if (disable_rtc_set)
993		return;
994
995	s = splclock();
996	tm = time.tv_sec;
997	splx(s);
998
999#ifdef PC98
1000	rtc_serialcom(0x01);	/* Register shift command. */
1001
1002	/* Calculate local time	to put in RTC */
1003
1004	tm -= tz.tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
1005
1006	rtc_outb(bin2bcd(tm%60)); tm /= 60;	/* Write back Seconds */
1007	rtc_outb(bin2bcd(tm%60)); tm /= 60;	/* Write back Minutes */
1008	rtc_outb(bin2bcd(tm%24)); tm /= 24;	/* Write back Hours   */
1009
1010	/* We have now the days	since 01-01-1970 in tm */
1011	wd = (tm+4)%7;
1012	for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
1013	     tm >= m;
1014	     y++,      m = DAYSPERYEAR + LEAPYEAR(y))
1015	     tm -= m;
1016
1017	/* Now we have the years in y and the day-of-the-year in tm */
1018	for (m = 0; ; m++) {
1019		int ml;
1020
1021		ml = daysinmonth[m];
1022		if (m == 1 && LEAPYEAR(y))
1023			ml++;
1024		if (tm < ml)
1025			break;
1026		tm -= ml;
1027	}
1028
1029	m++;
1030	rtc_outb(bin2bcd(tm+1));		/* Write back Day     */
1031	rtc_outb((m << 4) | wd);		/* Write back Month & Weekday  */
1032	rtc_outb(bin2bcd(y%100));		/* Write back Year    */
1033
1034	rtc_serialcom(0x02);	/* Time set & Counter hold command. */
1035	rtc_serialcom(0x00);	/* Register hold command. */
1036#else
1037	/* Disable RTC updates and interrupts. */
1038	writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR);
1039
1040	/* Calculate local time	to put in RTC */
1041
1042	tm -= tz.tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
1043
1044	writertc(RTC_SEC, bin2bcd(tm%60)); tm /= 60;	/* Write back Seconds */
1045	writertc(RTC_MIN, bin2bcd(tm%60)); tm /= 60;	/* Write back Minutes */
1046	writertc(RTC_HRS, bin2bcd(tm%24)); tm /= 24;	/* Write back Hours   */
1047
1048	/* We have now the days	since 01-01-1970 in tm */
1049	writertc(RTC_WDAY, (tm+4)%7);			/* Write back Weekday */
1050	for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
1051	     tm >= m;
1052	     y++,      m = DAYSPERYEAR + LEAPYEAR(y))
1053	     tm -= m;
1054
1055	/* Now we have the years in y and the day-of-the-year in tm */
1056	writertc(RTC_YEAR, bin2bcd(y%100));		/* Write back Year    */
1057#ifdef USE_RTC_CENTURY
1058	writertc(RTC_CENTURY, bin2bcd(y/100));		/* ... and Century    */
1059#endif
1060	for (m = 0; ; m++) {
1061		int ml;
1062
1063		ml = daysinmonth[m];
1064		if (m == 1 && LEAPYEAR(y))
1065			ml++;
1066		if (tm < ml)
1067			break;
1068		tm -= ml;
1069	}
1070
1071	writertc(RTC_MONTH, bin2bcd(m + 1));            /* Write back Month   */
1072	writertc(RTC_DAY, bin2bcd(tm + 1));             /* Write back Month Day */
1073
1074	/* Reenable RTC updates and interrupts. */
1075	writertc(RTC_STATUSB, rtc_statusb);
1076#endif
1077}
1078
1079/*
1080 * Start both clocks running.
1081 */
1082void
1083cpu_initclocks()
1084{
1085#ifndef PC98
1086	int diag;
1087
1088	if (statclock_disable) {
1089		/*
1090		 * The stat interrupt mask is different without the
1091		 * statistics clock.  Also, don't set the interrupt
1092		 * flag which would normally cause the RTC to generate
1093		 * interrupts.
1094		 */
1095		stat_imask = HWI_MASK | SWI_MASK;
1096		rtc_statusb = RTCSB_24HR;
1097	} else {
1098	        /* Setting stathz to nonzero early helps avoid races. */
1099		stathz = RTC_NOPROFRATE;
1100		profhz = RTC_PROFRATE;
1101        }
1102#endif
1103
1104	/* Finish initializing 8253 timer 0. */
1105	register_intr(/* irq */ 0, /* XXX id */ 0, /* flags */ 0,
1106		      /* XXX */ (inthand2_t *)clkintr, &clk_imask,
1107		      /* unit */ 0);
1108	INTREN(IRQ0);
1109#if defined(I586_CPU) || defined(I686_CPU)
1110	/*
1111	 * Finish setting up anti-jitter measures.
1112	 */
1113	if (i586_ctr_freq != 0)
1114		i586_ctr_bias = rdtsc();
1115#endif
1116
1117#ifndef PC98
1118	/* Initialize RTC. */
1119	writertc(RTC_STATUSA, rtc_statusa);
1120	writertc(RTC_STATUSB, RTCSB_24HR);
1121
1122	/* Don't bother enabling the statistics clock. */
1123	if (statclock_disable)
1124		return;
1125	diag = rtcin(RTC_DIAG);
1126	if (diag != 0)
1127		printf("RTC BIOS diagnostic error %b\n", diag, RTCDG_BITS);
1128	register_intr(/* irq */ 8, /* XXX id */ 1, /* flags */ 0,
1129		      /* XXX */ (inthand2_t *)rtcintr, &stat_imask,
1130		      /* unit */ 0);
1131	INTREN(IRQ8);
1132	writertc(RTC_STATUSB, rtc_statusb);
1133#endif
1134}
1135
1136void
1137setstatclockrate(int newhz)
1138{
1139#ifndef PC98
1140	if (newhz == RTC_PROFRATE)
1141		rtc_statusa = RTCSA_DIVIDER | RTCSA_PROF;
1142	else
1143		rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
1144	writertc(RTC_STATUSA, rtc_statusa);
1145#endif
1146}
1147
1148static int
1149sysctl_machdep_i8254_freq SYSCTL_HANDLER_ARGS
1150{
1151	int error;
1152	u_int freq;
1153
1154	/*
1155	 * Use `i8254' instead of `timer' in external names because `timer'
1156	 * is is too generic.  Should use it everywhere.
1157	 */
1158	freq = timer_freq;
1159	error = sysctl_handle_opaque(oidp, &freq, sizeof freq, req);
1160	if (error == 0 && req->newptr != NULL) {
1161		if (timer0_state != 0)
1162			return (EBUSY);	/* too much trouble to handle */
1163		set_timer_freq(freq, hz);
1164#if defined(I586_CPU) || defined(I686_CPU)
1165		set_i586_ctr_freq(i586_ctr_freq, timer_freq);
1166#endif
1167	}
1168	return (error);
1169}
1170
1171SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW,
1172	    0, sizeof(u_int), sysctl_machdep_i8254_freq, "I", "");
1173
1174#if defined(I586_CPU) || defined(I686_CPU)
1175static void
1176set_i586_ctr_freq(u_int i586_freq, u_int i8254_freq)
1177{
1178	u_int comultiplier, multiplier;
1179	u_long ef;
1180
1181	if (i586_freq == 0) {
1182		i586_ctr_freq = i586_freq;
1183		return;
1184	}
1185	comultiplier = ((unsigned long long)i586_freq
1186			<< I586_CTR_COMULTIPLIER_SHIFT) / i8254_freq;
1187	multiplier = (1000000LL << I586_CTR_MULTIPLIER_SHIFT) / i586_freq;
1188	ef = read_eflags();
1189	disable_intr();
1190	i586_ctr_freq = i586_freq;
1191	i586_ctr_comultiplier = comultiplier;
1192	i586_ctr_multiplier = multiplier;
1193	write_eflags(ef);
1194}
1195
1196static int
1197sysctl_machdep_i586_freq SYSCTL_HANDLER_ARGS
1198{
1199	int error;
1200	u_int freq;
1201
1202	if (cpu_class != CPUCLASS_586 && cpu_class != CPUCLASS_686)
1203		return (EOPNOTSUPP);
1204	freq = i586_ctr_freq;
1205	error = sysctl_handle_opaque(oidp, &freq, sizeof freq, req);
1206	if (error == 0 && req->newptr != NULL)
1207		set_i586_ctr_freq(freq, timer_freq);
1208	return (error);
1209}
1210
1211SYSCTL_PROC(_machdep, OID_AUTO, i586_freq, CTLTYPE_INT | CTLFLAG_RW,
1212	    0, sizeof(u_int), sysctl_machdep_i586_freq, "I", "");
1213#endif /* defined(I586_CPU) || defined(I686_CPU) */
1214