xref: /netbsd-src/sys/arch/atari/dev/clock.c (revision 10ad5ffa714ce1a679dcc9dd8159648df2d67b5a)
1 /*	$NetBSD: clock.c,v 1.49 2009/07/07 16:16:18 tsutsui Exp $	*/
2 
3 /*
4  * Copyright (c) 1982, 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * the Systems Programming Group of the University of Utah Computer
9  * Science Department.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * from: Utah $Hdr: clock.c 1.18 91/01/21$
36  *
37  *	@(#)clock.c	7.6 (Berkeley) 5/7/91
38  */
39 /*
40  * Copyright (c) 1988 University of Utah.
41  *
42  * This code is derived from software contributed to Berkeley by
43  * the Systems Programming Group of the University of Utah Computer
44  * Science Department.
45  *
46  * Redistribution and use in source and binary forms, with or without
47  * modification, are permitted provided that the following conditions
48  * are met:
49  * 1. Redistributions of source code must retain the above copyright
50  *    notice, this list of conditions and the following disclaimer.
51  * 2. Redistributions in binary form must reproduce the above copyright
52  *    notice, this list of conditions and the following disclaimer in the
53  *    documentation and/or other materials provided with the distribution.
54  * 3. All advertising materials mentioning features or use of this software
55  *    must display the following acknowledgement:
56  *	This product includes software developed by the University of
57  *	California, Berkeley and its contributors.
58  * 4. Neither the name of the University nor the names of its contributors
59  *    may be used to endorse or promote products derived from this software
60  *    without specific prior written permission.
61  *
62  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
63  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
64  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
65  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
66  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
67  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
68  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
69  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
70  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
71  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
72  * SUCH DAMAGE.
73  *
74  * from: Utah $Hdr: clock.c 1.18 91/01/21$
75  *
76  *	@(#)clock.c	7.6 (Berkeley) 5/7/91
77  */
78 
79 #include <sys/cdefs.h>
80 __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.49 2009/07/07 16:16:18 tsutsui Exp $");
81 
82 #include <sys/param.h>
83 #include <sys/kernel.h>
84 #include <sys/systm.h>
85 #include <sys/device.h>
86 #include <sys/uio.h>
87 #include <sys/conf.h>
88 #include <sys/proc.h>
89 #include <sys/event.h>
90 #include <sys/timetc.h>
91 
92 #include <dev/clock_subr.h>
93 
94 #include <machine/psl.h>
95 #include <machine/cpu.h>
96 #include <machine/iomap.h>
97 #include <machine/mfp.h>
98 #include <atari/dev/clockreg.h>
99 #include <atari/dev/clockvar.h>
100 #include <atari/atari/device.h>
101 
102 #if defined(GPROF) && defined(PROFTIMER)
103 #include <machine/profile.h>
104 #endif
105 
106 static int	atari_rtc_get(todr_chip_handle_t, struct clock_ymdhms *);
107 static int	atari_rtc_set(todr_chip_handle_t, struct clock_ymdhms *);
108 
109 /*
110  * The MFP clock runs at 2457600Hz. We use a {system,stat,prof}clock divider
111  * of 200. Therefore the timer runs at an effective rate of:
112  * 2457600/200 = 12288Hz.
113  */
114 #define CLOCK_HZ	12288
115 
116 static u_int clk_getcounter(struct timecounter *);
117 
118 static struct timecounter clk_timecounter = {
119 	clk_getcounter,	/* get_timecount */
120 	0,		/* no poll_pps */
121 	~0u,		/* counter_mask */
122 	CLOCK_HZ,	/* frequency */
123 	"clock",	/* name, overriden later */
124 	100,		/* quality */
125 	NULL,		/* prev */
126 	NULL,		/* next */
127 };
128 
129 /*
130  * Machine-dependent clock routines.
131  *
132  * Inittodr initializes the time of day hardware which provides
133  * date functions.
134  *
135  * Resettodr restores the time of day hardware after a time change.
136  */
137 
138 struct clock_softc {
139 	struct device	sc_dev;
140 	int		sc_flags;
141 };
142 
143 /*
144  *  'sc_flags' state info. Only used by the rtc-device functions.
145  */
146 #define	RTC_OPEN	1
147 
148 dev_type_open(rtcopen);
149 dev_type_close(rtcclose);
150 dev_type_read(rtcread);
151 dev_type_write(rtcwrite);
152 
153 static void	clockattach(struct device *, struct device *, void *);
154 static int	clockmatch(struct device *, struct cfdata *, void *);
155 
156 CFATTACH_DECL(clock, sizeof(struct clock_softc),
157     clockmatch, clockattach, NULL, NULL);
158 
159 extern struct cfdriver clock_cd;
160 
161 const struct cdevsw rtc_cdevsw = {
162 	rtcopen, rtcclose, rtcread, rtcwrite, noioctl,
163 	nostop, notty, nopoll, nommap, nokqfilter,
164 };
165 
166 void statintr(struct clockframe);
167 
168 static int	twodigits(char *, int);
169 
170 static int	divisor;	/* Systemclock divisor	*/
171 
172 /*
173  * Statistics and profile clock intervals and variances. Variance must
174  * be a power of 2. Since this gives us an even number, not an odd number,
175  * we discard one case and compensate. That is, a variance of 64 would
176  * give us offsets in [0..63]. Instead, we take offsets in [1..63].
177  * This is symmetric around the point 32, or statvar/2, and thus averages
178  * to that value (assuming uniform random numbers).
179  */
180 #ifdef STATCLOCK
181 static int	statvar = 32;	/* {stat,prof}clock variance		*/
182 static int	statmin;	/* statclock divisor - variance/2	*/
183 static int	profmin;	/* profclock divisor - variance/2	*/
184 static int	clk2min;	/* current, from above choices		*/
185 #endif
186 
187 int
188 clockmatch(struct device *pdp, struct cfdata *cfp, void *auxp)
189 {
190 
191 	if (!strcmp("clock", auxp))
192 		return 1;
193 	return 0;
194 }
195 
196 /*
197  * Start the real-time clock.
198  */
199 void clockattach(struct device *pdp, struct device *dp, void *auxp)
200 {
201 
202 	struct clock_softc *sc = (void *)dp;
203 	static struct todr_chip_handle	tch;
204 
205 	tch.todr_gettime_ymdhms = atari_rtc_get;
206 	tch.todr_settime_ymdhms = atari_rtc_set;
207 	tch.todr_setwen = NULL;
208 
209 	todr_attach(&tch);
210 
211 	sc->sc_flags = 0;
212 
213 	/*
214 	 * Initialize Timer-A in the ST-MFP. We use a divisor of 200.
215 	 * The MFP clock runs at 2457600Hz. Therefore the timer runs
216 	 * at an effective rate of: 2457600/200 = 12288Hz. The
217 	 * following expression works for 48, 64 or 96 hz.
218 	 */
219 	divisor       = CLOCK_HZ/hz;
220 	MFP->mf_tacr  = 0;		/* Stop timer			*/
221 	MFP->mf_iera &= ~IA_TIMA;	/* Disable timer interrupts	*/
222 	MFP->mf_tadr  = divisor;	/* Set divisor			*/
223 
224 	clk_timecounter.tc_frequency = CLOCK_HZ;
225 
226 	if (hz != 48 && hz != 64 && hz != 96) { /* XXX */
227 		printf (": illegal value %d for systemclock, reset to %d\n\t",
228 								hz, 64);
229 		hz = 64;
230 	}
231 	printf(": system hz %d timer-A divisor 200/%d\n", hz, divisor);
232 	tc_init(&clk_timecounter);
233 
234 #ifdef STATCLOCK
235 	if ((stathz == 0) || (stathz > hz) || (CLOCK_HZ % stathz))
236 		stathz = hz;
237 	if ((profhz == 0) || (profhz > (hz << 1)) || (CLOCK_HZ % profhz))
238 		profhz = hz << 1;
239 
240 	MFP->mf_tcdcr &= 0x7;			/* Stop timer		*/
241 	MFP->mf_ierb  &= ~IB_TIMC;		/* Disable timer inter.	*/
242 	MFP->mf_tcdr   = CLOCK_HZ/stathz;	/* Set divisor		*/
243 
244 	statmin  = (CLOCK_HZ/stathz) - (statvar >> 1);
245 	profmin  = (CLOCK_HZ/profhz) - (statvar >> 1);
246 	clk2min  = statmin;
247 #endif /* STATCLOCK */
248 }
249 
250 void cpu_initclocks(void)
251 {
252 
253 	MFP->mf_tacr  = T_Q200;		/* Start timer			*/
254 	MFP->mf_ipra  = (u_int8_t)~IA_TIMA;/* Clear pending interrupts	*/
255 	MFP->mf_iera |= IA_TIMA;	/* Enable timer interrupts	*/
256 	MFP->mf_imra |= IA_TIMA;	/*    .....			*/
257 
258 #ifdef STATCLOCK
259 	MFP->mf_tcdcr = (MFP->mf_tcdcr & 0x7) | (T_Q200<<4); /* Start	*/
260 	MFP->mf_iprb  = (u_int8_t)~IB_TIMC;/* Clear pending interrupts	*/
261 	MFP->mf_ierb |= IB_TIMC;	/* Enable timer interrupts	*/
262 	MFP->mf_imrb |= IB_TIMC;	/*    .....			*/
263 #endif /* STATCLOCK */
264 }
265 
266 void
267 setstatclockrate(int newhz)
268 {
269 
270 #ifdef STATCLOCK
271 	if (newhz == stathz)
272 		clk2min = statmin;
273 	else clk2min = profmin;
274 #endif /* STATCLOCK */
275 }
276 
277 #ifdef STATCLOCK
278 void
279 statintr(struct clockframe frame)
280 {
281 	register int	var, r;
282 
283 	var = statvar - 1;
284 	do {
285 		r = random() & var;
286 	} while (r == 0);
287 
288 	/*
289 	 * Note that we are always lagging behind as the new divisor
290 	 * value will not be loaded until the next interrupt. This
291 	 * shouldn't disturb the median frequency (I think ;-) ) as
292 	 * only the value used when switching frequencies is used
293 	 * twice. This shouldn't happen very often.
294 	 */
295 	MFP->mf_tcdr = clk2min + r;
296 
297 	statclock(&frame);
298 }
299 #endif /* STATCLOCK */
300 
301 static u_int
302 clk_getcounter(struct timecounter *tc)
303 {
304 	uint32_t delta, count, cur_hardclock;
305 	uint8_t ipra, tadr;
306 	int s;
307 	static uint32_t lastcount;
308 
309 	s = splhigh();
310 	cur_hardclock = hardclock_ticks;
311 	ipra = MFP->mf_ipra;
312 	tadr = MFP->mf_tadr;
313 	delta = divisor - tadr;
314 
315 	if (ipra & IA_TIMA)
316 		delta += divisor;
317 	splx(s);
318 
319 	count = (divisor * cur_hardclock) + delta;
320 	if ((int32_t)(count - lastcount) < 0) {
321 		/* XXX wrapped; maybe hardclock() is blocked more than 2/HZ */
322 		count = lastcount + 1;
323 	}
324 	lastcount = count;
325 
326 	return count;
327 }
328 
329 #define TIMB_FREQ	614400
330 #define TIMB_LIMIT	256
331 
332 void
333 init_delay(void)
334 {
335 
336 	/*
337 	 * Initialize Timer-B in the ST-MFP. This timer is used by
338 	 * the 'delay' function below. This timer is setup to be
339 	 * continueously counting from 255 back to zero at a
340 	 * frequency of 614400Hz. We do this *early* in the
341 	 * initialisation process.
342 	 */
343 	MFP->mf_tbcr  = 0;		/* Stop timer			*/
344 	MFP->mf_iera &= ~IA_TIMB;	/* Disable timer interrupts	*/
345 	MFP->mf_tbdr  = 0;
346 	MFP->mf_tbcr  = T_Q004;	/* Start timer			*/
347 }
348 
349 /*
350  * Wait "n" microseconds.
351  * Relies on MFP-Timer B counting down from TIMB_LIMIT at TIMB_FREQ Hz.
352  * Note: timer had better have been programmed before this is first used!
353  */
354 void
355 delay(unsigned int n)
356 {
357 	int	ticks, otick, remaining;
358 
359 	/*
360 	 * Read the counter first, so that the rest of the setup overhead is
361 	 * counted.
362 	 */
363 	otick = MFP->mf_tbdr;
364 
365 	if (n <= UINT_MAX / TIMB_FREQ) {
366 		/*
367 		 * For unsigned arithmetic, division can be replaced with
368 		 * multiplication with the inverse and a shift.
369 		 */
370 		remaining = n * TIMB_FREQ / 1000000;
371 	} else {
372 		/* This is a very long delay.
373 		 * Being slow here doesn't matter.
374 		 */
375 		remaining = (unsigned long long) n * TIMB_FREQ / 1000000;
376 	}
377 
378 	while (remaining > 0) {
379 		ticks = MFP->mf_tbdr;
380 		if (ticks > otick)
381 			remaining -= TIMB_LIMIT - (ticks - otick);
382 		else
383 			remaining -= otick - ticks;
384 		otick = ticks;
385 	}
386 }
387 
388 #ifdef GPROF
389 /*
390  * profclock() is expanded in line in lev6intr() unless profiling kernel.
391  * Assumes it is called with clock interrupts blocked.
392  */
393 profclock(void *pc, int ps)
394 {
395 
396 	/*
397 	 * Came from user mode.
398 	 * If this process is being profiled record the tick.
399 	 */
400 	if (USERMODE(ps)) {
401 		if (p->p_stats.p_prof.pr_scale)
402 			addupc(pc, &curproc->p_stats.p_prof, 1);
403 	}
404 	/*
405 	 * Came from kernel (supervisor) mode.
406 	 * If we are profiling the kernel, record the tick.
407 	 */
408 	else if (profiling < 2) {
409 		register int s = pc - s_lowpc;
410 
411 		if (s < s_textsize)
412 			kcount[s / (HISTFRACTION * sizeof(*kcount))]++;
413 	}
414 	/*
415 	 * Kernel profiling was on but has been disabled.
416 	 * Mark as no longer profiling kernel and if all profiling done,
417 	 * disable the clock.
418 	 */
419 	if (profiling && (profon & PRF_KERNEL)) {
420 		profon &= ~PRF_KERNEL;
421 		if (profon == PRF_NONE)
422 			stopprofclock();
423 	}
424 }
425 #endif
426 
427 /***********************************************************************
428  *                   Real Time Clock support                           *
429  ***********************************************************************/
430 
431 u_int mc146818_read(void *rtc, u_int regno)
432 {
433 
434 	((struct rtc *)rtc)->rtc_regno = regno;
435 	return ((struct rtc *)rtc)->rtc_data & 0377;
436 }
437 
438 void mc146818_write(void *rtc, u_int regno, u_int value)
439 {
440 
441 	((struct rtc *)rtc)->rtc_regno = regno;
442 	((struct rtc *)rtc)->rtc_data  = value;
443 }
444 
445 static int
446 atari_rtc_get(todr_chip_handle_t todr, struct clock_ymdhms *dtp)
447 {
448 	int			sps;
449 	mc_todregs		clkregs;
450 	u_int			regb;
451 
452 	sps = splhigh();
453 	regb = mc146818_read(RTC, MC_REGB);
454 	MC146818_GETTOD(RTC, &clkregs);
455 	splx(sps);
456 
457 	regb &= MC_REGB_24HR|MC_REGB_BINARY;
458 	if (regb != (MC_REGB_24HR|MC_REGB_BINARY)) {
459 		printf("Error: Nonstandard RealTimeClock Configuration -"
460 			" value ignored\n"
461 			"       A write to /dev/rtc will correct this.\n");
462 			return 0;
463 	}
464 	if (clkregs[MC_SEC] > 59)
465 		return -1;
466 	if (clkregs[MC_MIN] > 59)
467 		return -1;
468 	if (clkregs[MC_HOUR] > 23)
469 		return -1;
470 	if (range_test(clkregs[MC_DOM], 1, 31))
471 		return -1;
472 	if (range_test(clkregs[MC_MONTH], 1, 12))
473 		return -1;
474 	if (clkregs[MC_YEAR] > 99)
475 		return -1;
476 
477 	dtp->dt_year = clkregs[MC_YEAR] + GEMSTARTOFTIME;
478 	dtp->dt_mon  = clkregs[MC_MONTH];
479 	dtp->dt_day  = clkregs[MC_DOM];
480 	dtp->dt_hour = clkregs[MC_HOUR];
481 	dtp->dt_min  = clkregs[MC_MIN];
482 	dtp->dt_sec  = clkregs[MC_SEC];
483 
484 	return 0;
485 }
486 
487 static int
488 atari_rtc_set(todr_chip_handle_t todr, struct clock_ymdhms *dtp)
489 {
490 	int s;
491 	mc_todregs clkregs;
492 
493 	clkregs[MC_YEAR] = dtp->dt_year - GEMSTARTOFTIME;
494 	clkregs[MC_MONTH] = dtp->dt_mon;
495 	clkregs[MC_DOM] = dtp->dt_day;
496 	clkregs[MC_HOUR] = dtp->dt_hour;
497 	clkregs[MC_MIN] = dtp->dt_min;
498 	clkregs[MC_SEC] = dtp->dt_sec;
499 
500 	s = splclock();
501 	MC146818_PUTTOD(RTC, &clkregs);
502 	splx(s);
503 
504 	return 0;
505 }
506 
507 /***********************************************************************
508  *                   RTC-device support				       *
509  ***********************************************************************/
510 int
511 rtcopen(dev_t dev, int flag, int mode, struct lwp *l)
512 {
513 	int			unit = minor(dev);
514 	struct clock_softc	*sc;
515 
516 	sc = device_lookup_private(&clock_cd, unit);
517 	if (sc == NULL)
518 		return ENXIO;
519 	if (sc->sc_flags & RTC_OPEN)
520 		return EBUSY;
521 
522 	sc->sc_flags = RTC_OPEN;
523 	return 0;
524 }
525 
526 int
527 rtcclose(dev_t dev, int flag, int mode, struct lwp *l)
528 {
529 	int			unit = minor(dev);
530 	struct clock_softc	*sc = device_lookup_private(&clock_cd, unit);
531 
532 	sc->sc_flags = 0;
533 	return 0;
534 }
535 
536 int
537 rtcread(dev_t dev, struct uio *uio, int flags)
538 {
539 	struct clock_softc	*sc;
540 	mc_todregs		clkregs;
541 	int			s, length;
542 	char			buffer[16];
543 
544 	sc = device_lookup_private(&clock_cd, minor(dev));
545 
546 	s = splhigh();
547 	MC146818_GETTOD(RTC, &clkregs);
548 	splx(s);
549 
550 	sprintf(buffer, "%4d%02d%02d%02d%02d.%02d\n",
551 	    clkregs[MC_YEAR] + GEMSTARTOFTIME,
552 	    clkregs[MC_MONTH], clkregs[MC_DOM],
553 	    clkregs[MC_HOUR], clkregs[MC_MIN], clkregs[MC_SEC]);
554 
555 	if (uio->uio_offset > strlen(buffer))
556 		return 0;
557 
558 	length = strlen(buffer) - uio->uio_offset;
559 	if (length > uio->uio_resid)
560 		length = uio->uio_resid;
561 
562 	return uiomove((void *)buffer, length, uio);
563 }
564 
565 static int
566 twodigits(char *buffer, int pos)
567 {
568 	int result = 0;
569 
570 	if (buffer[pos] >= '0' && buffer[pos] <= '9')
571 		result = (buffer[pos] - '0') * 10;
572 	if (buffer[pos+1] >= '0' && buffer[pos+1] <= '9')
573 		result += (buffer[pos+1] - '0');
574 	return result;
575 }
576 
577 int
578 rtcwrite(dev_t dev, struct uio *uio, int flags)
579 {
580 	mc_todregs		clkregs;
581 	int			s, length, error;
582 	char			buffer[16];
583 
584 	/*
585 	 * We require atomic updates!
586 	 */
587 	length = uio->uio_resid;
588 	if (uio->uio_offset || (length != sizeof(buffer)
589 	  && length != sizeof(buffer - 1)))
590 		return EINVAL;
591 
592 	if ((error = uiomove((void *)buffer, sizeof(buffer), uio)))
593 		return error;
594 
595 	if (length == sizeof(buffer) && buffer[sizeof(buffer) - 1] != '\n')
596 		return EINVAL;
597 
598 	s = splclock();
599 	mc146818_write(RTC, MC_REGB,
600 	    mc146818_read(RTC, MC_REGB) | MC_REGB_24HR | MC_REGB_BINARY);
601 	MC146818_GETTOD(RTC, &clkregs);
602 	splx(s);
603 
604 	clkregs[MC_SEC]   = twodigits(buffer, 13);
605 	clkregs[MC_MIN]   = twodigits(buffer, 10);
606 	clkregs[MC_HOUR]  = twodigits(buffer, 8);
607 	clkregs[MC_DOM]   = twodigits(buffer, 6);
608 	clkregs[MC_MONTH] = twodigits(buffer, 4);
609 	s = twodigits(buffer, 0) * 100 + twodigits(buffer, 2);
610 	clkregs[MC_YEAR]  = s - GEMSTARTOFTIME;
611 
612 	s = splclock();
613 	MC146818_PUTTOD(RTC, &clkregs);
614 	splx(s);
615 
616 	return 0;
617 }
618