xref: /netbsd-src/sys/arch/atari/dev/clock.c (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: clock.c,v 1.46 2009/03/18 10:22:24 cegger 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 1.46 2009/03/18 10:22:24 cegger 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/atari/device.h>
100 
101 #if defined(GPROF) && defined(PROFTIMER)
102 #include <machine/profile.h>
103 #endif
104 
105 static int	atari_rtc_get(todr_chip_handle_t, struct clock_ymdhms *);
106 static int	atari_rtc_set(todr_chip_handle_t, struct clock_ymdhms *);
107 
108 /*
109  * The MFP clock runs at 2457600Hz. We use a {system,stat,prof}clock divider
110  * of 200. Therefore the timer runs at an effective rate of:
111  * 2457600/200 = 12288Hz.
112  */
113 #define CLOCK_HZ	12288
114 
115 static u_int clk_getcounter(struct timecounter *);
116 
117 static struct timecounter clk_timecounter = {
118 	clk_getcounter,	/* get_timecount */
119 	0,		/* no poll_pps */
120 	~0u,		/* counter_mask */
121 	CLOCK_HZ,	/* frequency */
122 	"clock",	/* name, overriden later */
123 	100,		/* quality */
124 	NULL,		/* prev */
125 	NULL,		/* next */
126 };
127 
128 /*
129  * Machine-dependent clock routines.
130  *
131  * Inittodr initializes the time of day hardware which provides
132  * date functions.
133  *
134  * Resettodr restores the time of day hardware after a time change.
135  */
136 
137 struct clock_softc {
138 	struct device	sc_dev;
139 	int		sc_flags;
140 };
141 
142 /*
143  *  'sc_flags' state info. Only used by the rtc-device functions.
144  */
145 #define	RTC_OPEN	1
146 
147 dev_type_open(rtcopen);
148 dev_type_close(rtcclose);
149 dev_type_read(rtcread);
150 dev_type_write(rtcwrite);
151 
152 static void	clockattach(struct device *, struct device *, void *);
153 static int	clockmatch(struct device *, struct cfdata *, void *);
154 
155 CFATTACH_DECL(clock, sizeof(struct clock_softc),
156     clockmatch, clockattach, NULL, NULL);
157 
158 extern struct cfdriver clock_cd;
159 
160 const struct cdevsw rtc_cdevsw = {
161 	rtcopen, rtcclose, rtcread, rtcwrite, noioctl,
162 	nostop, notty, nopoll, nommap, nokqfilter,
163 };
164 
165 void statintr(struct clockframe);
166 
167 static int	twodigits(char *, int);
168 
169 static int	divisor;	/* Systemclock divisor	*/
170 
171 /*
172  * Statistics and profile clock intervals and variances. Variance must
173  * be a power of 2. Since this gives us an even number, not an odd number,
174  * we discard one case and compensate. That is, a variance of 64 would
175  * give us offsets in [0..63]. Instead, we take offsets in [1..63].
176  * This is symmetric around the point 32, or statvar/2, and thus averages
177  * to that value (assuming uniform random numbers).
178  */
179 #ifdef STATCLOCK
180 static int	statvar = 32;	/* {stat,prof}clock variance		*/
181 static int	statmin;	/* statclock divisor - variance/2	*/
182 static int	profmin;	/* profclock divisor - variance/2	*/
183 static int	clk2min;	/* current, from above choices		*/
184 #endif
185 
186 int
187 clockmatch(struct device *pdp, struct cfdata *cfp, void *auxp)
188 {
189 	if (!atari_realconfig) {
190 	    /*
191 	     * Initialize Timer-B in the ST-MFP. This timer is used by
192 	     * the 'delay' function below. This timer is setup to be
193 	     * continueously counting from 255 back to zero at a
194 	     * frequency of 614400Hz. We do this *early* in the
195 	     * initialisation process.
196 	     */
197 	    MFP->mf_tbcr  = 0;		/* Stop timer			*/
198 	    MFP->mf_iera &= ~IA_TIMB;	/* Disable timer interrupts	*/
199 	    MFP->mf_tbdr  = 0;
200 	    MFP->mf_tbcr  = T_Q004;	/* Start timer			*/
201 
202 	    return 0;
203 	}
204 	if(!strcmp("clock", auxp))
205 		return(1);
206 	return(0);
207 }
208 
209 /*
210  * Start the real-time clock.
211  */
212 void clockattach(pdp, dp, auxp)
213 struct device	*pdp, *dp;
214 void		*auxp;
215 {
216 	struct clock_softc *sc = (void *)dp;
217 	static struct todr_chip_handle	tch;
218 
219 	tch.todr_gettime_ymdhms = atari_rtc_get;
220 	tch.todr_settime_ymdhms = atari_rtc_set;
221 	tch.todr_setwen = NULL;
222 
223 	todr_attach(&tch);
224 
225 	sc->sc_flags = 0;
226 
227 	/*
228 	 * Initialize Timer-A in the ST-MFP. We use a divisor of 200.
229 	 * The MFP clock runs at 2457600Hz. Therefore the timer runs
230 	 * at an effective rate of: 2457600/200 = 12288Hz. The
231 	 * following expression works for 48, 64 or 96 hz.
232 	 */
233 	divisor       = CLOCK_HZ/hz;
234 	MFP->mf_tacr  = 0;		/* Stop timer			*/
235 	MFP->mf_iera &= ~IA_TIMA;	/* Disable timer interrupts	*/
236 	MFP->mf_tadr  = divisor;	/* Set divisor			*/
237 
238 	clk_timecounter.tc_frequency = CLOCK_HZ;
239 
240 	if (hz != 48 && hz != 64 && hz != 96) { /* XXX */
241 		printf (": illegal value %d for systemclock, reset to %d\n\t",
242 								hz, 64);
243 		hz = 64;
244 	}
245 	printf(": system hz %d timer-A divisor 200/%d\n", hz, divisor);
246 	tc_init(&clk_timecounter);
247 
248 #ifdef STATCLOCK
249 	if ((stathz == 0) || (stathz > hz) || (CLOCK_HZ % stathz))
250 		stathz = hz;
251 	if ((profhz == 0) || (profhz > (hz << 1)) || (CLOCK_HZ % profhz))
252 		profhz = hz << 1;
253 
254 	MFP->mf_tcdcr &= 0x7;			/* Stop timer		*/
255 	MFP->mf_ierb  &= ~IB_TIMC;		/* Disable timer inter.	*/
256 	MFP->mf_tcdr   = CLOCK_HZ/stathz;	/* Set divisor		*/
257 
258 	statmin  = (CLOCK_HZ/stathz) - (statvar >> 1);
259 	profmin  = (CLOCK_HZ/profhz) - (statvar >> 1);
260 	clk2min  = statmin;
261 #endif /* STATCLOCK */
262 
263 }
264 
265 void cpu_initclocks(void)
266 {
267 	MFP->mf_tacr  = T_Q200;		/* Start timer			*/
268 	MFP->mf_ipra  = (u_int8_t)~IA_TIMA;/* Clear pending interrupts	*/
269 	MFP->mf_iera |= IA_TIMA;	/* Enable timer interrupts	*/
270 	MFP->mf_imra |= IA_TIMA;	/*    .....			*/
271 
272 #ifdef STATCLOCK
273 	MFP->mf_tcdcr = (MFP->mf_tcdcr & 0x7) | (T_Q200<<4); /* Start	*/
274 	MFP->mf_iprb  = (u_int8_t)~IB_TIMC;/* Clear pending interrupts	*/
275 	MFP->mf_ierb |= IB_TIMC;	/* Enable timer interrupts	*/
276 	MFP->mf_imrb |= IB_TIMC;	/*    .....			*/
277 #endif /* STATCLOCK */
278 }
279 
280 void
281 setstatclockrate(int newhz)
282 {
283 #ifdef STATCLOCK
284 	if (newhz == stathz)
285 		clk2min = statmin;
286 	else clk2min = profmin;
287 #endif /* STATCLOCK */
288 }
289 
290 #ifdef STATCLOCK
291 void
292 statintr(struct clockframe frame)
293 {
294 	register int	var, r;
295 
296 	var = statvar - 1;
297 	do {
298 		r = random() & var;
299 	} while(r == 0);
300 
301 	/*
302 	 * Note that we are always lagging behind as the new divisor
303 	 * value will not be loaded until the next interrupt. This
304 	 * shouldn't disturb the median frequency (I think ;-) ) as
305 	 * only the value used when switching frequencies is used
306 	 * twice. This shouldn't happen very often.
307 	 */
308 	MFP->mf_tcdr = clk2min + r;
309 
310 	statclock(&frame);
311 }
312 #endif /* STATCLOCK */
313 
314 static u_int
315 clk_getcounter(struct timecounter *tc)
316 {
317 	u_int delta;
318 	u_char ipra, tadr;
319 	int s, cur_hardclock;
320 
321 	s = splhigh();
322 	ipra = MFP->mf_ipra;
323 	tadr = MFP->mf_tadr;
324 	delta = divisor - tadr;
325 
326 	if (ipra & IA_TIMA)
327 		delta += divisor;
328 	cur_hardclock = hardclock_ticks;
329 	splx(s);
330 
331 	return (divisor - tadr) + divisor * cur_hardclock;
332 }
333 
334 #define TIMB_FREQ	614400
335 #define TIMB_LIMIT	256
336 
337 /*
338  * Wait "n" microseconds.
339  * Relies on MFP-Timer B counting down from TIMB_LIMIT at TIMB_FREQ Hz.
340  * Note: timer had better have been programmed before this is first used!
341  */
342 void
343 delay(unsigned int n)
344 {
345 	int	ticks, otick, remaining;
346 
347 	/*
348 	 * Read the counter first, so that the rest of the setup overhead is
349 	 * counted.
350 	 */
351 	otick = MFP->mf_tbdr;
352 
353 	if (n <= UINT_MAX / TIMB_FREQ) {
354 		/*
355 		 * For unsigned arithmetic, division can be replaced with
356 		 * multiplication with the inverse and a shift.
357 		 */
358 		remaining = n * TIMB_FREQ / 1000000;
359 	} else {
360 		/* This is a very long delay.
361 		 * Being slow here doesn't matter.
362 		 */
363 		remaining = (unsigned long long) n * TIMB_FREQ / 1000000;
364 	}
365 
366 	while(remaining > 0) {
367 		ticks = MFP->mf_tbdr;
368 		if(ticks > otick)
369 			remaining -= TIMB_LIMIT - (ticks - otick);
370 		else
371 			remaining -= otick - ticks;
372 		otick = ticks;
373 	}
374 }
375 
376 #ifdef GPROF
377 /*
378  * profclock() is expanded in line in lev6intr() unless profiling kernel.
379  * Assumes it is called with clock interrupts blocked.
380  */
381 profclock(void *pc, int ps)
382 {
383 	/*
384 	 * Came from user mode.
385 	 * If this process is being profiled record the tick.
386 	 */
387 	if (USERMODE(ps)) {
388 		if (p->p_stats.p_prof.pr_scale)
389 			addupc(pc, &curproc->p_stats.p_prof, 1);
390 	}
391 	/*
392 	 * Came from kernel (supervisor) mode.
393 	 * If we are profiling the kernel, record the tick.
394 	 */
395 	else if (profiling < 2) {
396 		register int s = pc - s_lowpc;
397 
398 		if (s < s_textsize)
399 			kcount[s / (HISTFRACTION * sizeof (*kcount))]++;
400 	}
401 	/*
402 	 * Kernel profiling was on but has been disabled.
403 	 * Mark as no longer profiling kernel and if all profiling done,
404 	 * disable the clock.
405 	 */
406 	if (profiling && (profon & PRF_KERNEL)) {
407 		profon &= ~PRF_KERNEL;
408 		if (profon == PRF_NONE)
409 			stopprofclock();
410 	}
411 }
412 #endif
413 
414 /***********************************************************************
415  *                   Real Time Clock support                           *
416  ***********************************************************************/
417 
418 u_int mc146818_read(rtc, regno)
419 void	*rtc;
420 u_int	regno;
421 {
422 	((struct rtc *)rtc)->rtc_regno = regno;
423 	return(((struct rtc *)rtc)->rtc_data & 0377);
424 }
425 
426 void mc146818_write(rtc, regno, value)
427 void	*rtc;
428 u_int	regno, value;
429 {
430 	((struct rtc *)rtc)->rtc_regno = regno;
431 	((struct rtc *)rtc)->rtc_data  = value;
432 }
433 
434 static int
435 atari_rtc_get(todr_chip_handle_t todr, struct clock_ymdhms *dtp)
436 {
437 	int			sps;
438 	mc_todregs		clkregs;
439 	u_int			regb;
440 
441 	sps = splhigh();
442 	regb = mc146818_read(RTC, MC_REGB);
443 	MC146818_GETTOD(RTC, &clkregs);
444 	splx(sps);
445 
446 	regb &= MC_REGB_24HR|MC_REGB_BINARY;
447 	if (regb != (MC_REGB_24HR|MC_REGB_BINARY)) {
448 		printf("Error: Nonstandard RealTimeClock Configuration -"
449 			" value ignored\n"
450 			"       A write to /dev/rtc will correct this.\n");
451 			return(0);
452 	}
453 	if(clkregs[MC_SEC] > 59)
454 		return -1;
455 	if(clkregs[MC_MIN] > 59)
456 		return -1;
457 	if(clkregs[MC_HOUR] > 23)
458 		return -1;
459 	if(range_test(clkregs[MC_DOM], 1, 31))
460 		return -1;
461 	if (range_test(clkregs[MC_MONTH], 1, 12))
462 		return -1;
463 	if(clkregs[MC_YEAR] > 99)
464 		return -1;
465 
466 	dtp->dt_year = clkregs[MC_YEAR] + GEMSTARTOFTIME;
467 	dtp->dt_mon  = clkregs[MC_MONTH];
468 	dtp->dt_day  = clkregs[MC_DOM];
469 	dtp->dt_hour = clkregs[MC_HOUR];
470 	dtp->dt_min  = clkregs[MC_MIN];
471 	dtp->dt_sec  = clkregs[MC_SEC];
472 
473 	return 0;
474 }
475 
476 static int
477 atari_rtc_set(todr_chip_handle_t todr, struct clock_ymdhms *dtp)
478 {
479 	int s;
480 	mc_todregs clkregs;
481 
482 	clkregs[MC_YEAR] = dtp->dt_year - GEMSTARTOFTIME;
483 	clkregs[MC_MONTH] = dtp->dt_mon;
484 	clkregs[MC_DOM] = dtp->dt_day;
485 	clkregs[MC_HOUR] = dtp->dt_hour;
486 	clkregs[MC_MIN] = dtp->dt_min;
487 	clkregs[MC_SEC] = dtp->dt_sec;
488 
489 	s = splclock();
490 	MC146818_PUTTOD(RTC, &clkregs);
491 	splx(s);
492 
493 	return 0;
494 }
495 
496 /***********************************************************************
497  *                   RTC-device support				       *
498  ***********************************************************************/
499 int
500 rtcopen(dev_t dev, int flag, int mode, struct lwp *l)
501 {
502 	int			unit = minor(dev);
503 	struct clock_softc	*sc;
504 
505 	sc = device_lookup_private(&clock_cd, unit);
506 	if (sc == NULL)
507 		return ENXIO;
508 	if (sc->sc_flags & RTC_OPEN)
509 		return EBUSY;
510 
511 	sc->sc_flags = RTC_OPEN;
512 	return 0;
513 }
514 
515 int
516 rtcclose(dev_t dev, int flag, int mode, struct lwp *l)
517 {
518 	int			unit = minor(dev);
519 	struct clock_softc	*sc = device_lookup_private(&clock_cd, unit);
520 
521 	sc->sc_flags = 0;
522 	return 0;
523 }
524 
525 int
526 rtcread(dev_t dev, struct uio *uio, int flags)
527 {
528 	struct clock_softc	*sc;
529 	mc_todregs		clkregs;
530 	int			s, length;
531 	char			buffer[16];
532 
533 	sc = device_lookup_private(&clock_cd, minor(dev));
534 
535 	s = splhigh();
536 	MC146818_GETTOD(RTC, &clkregs);
537 	splx(s);
538 
539 	sprintf(buffer, "%4d%02d%02d%02d%02d.%02d\n",
540 	    clkregs[MC_YEAR] + GEMSTARTOFTIME,
541 	    clkregs[MC_MONTH], clkregs[MC_DOM],
542 	    clkregs[MC_HOUR], clkregs[MC_MIN], clkregs[MC_SEC]);
543 
544 	if (uio->uio_offset > strlen(buffer))
545 		return 0;
546 
547 	length = strlen(buffer) - uio->uio_offset;
548 	if (length > uio->uio_resid)
549 		length = uio->uio_resid;
550 
551 	return(uiomove((void *)buffer, length, uio));
552 }
553 
554 static int
555 twodigits(char *buffer, int pos)
556 {
557 	int result = 0;
558 
559 	if (buffer[pos] >= '0' && buffer[pos] <= '9')
560 		result = (buffer[pos] - '0') * 10;
561 	if (buffer[pos+1] >= '0' && buffer[pos+1] <= '9')
562 		result += (buffer[pos+1] - '0');
563 	return(result);
564 }
565 
566 int
567 rtcwrite(dev_t dev, struct uio *uio, int flags)
568 {
569 	mc_todregs		clkregs;
570 	int			s, length, error;
571 	char			buffer[16];
572 
573 	/*
574 	 * We require atomic updates!
575 	 */
576 	length = uio->uio_resid;
577 	if (uio->uio_offset || (length != sizeof(buffer)
578 	  && length != sizeof(buffer - 1)))
579 		return(EINVAL);
580 
581 	if ((error = uiomove((void *)buffer, sizeof(buffer), uio)))
582 		return(error);
583 
584 	if (length == sizeof(buffer) && buffer[sizeof(buffer) - 1] != '\n')
585 		return(EINVAL);
586 
587 	s = splclock();
588 	mc146818_write(RTC, MC_REGB,
589 		mc146818_read(RTC, MC_REGB) | MC_REGB_24HR | MC_REGB_BINARY);
590 	MC146818_GETTOD(RTC, &clkregs);
591 	splx(s);
592 
593 	clkregs[MC_SEC]   = twodigits(buffer, 13);
594 	clkregs[MC_MIN]   = twodigits(buffer, 10);
595 	clkregs[MC_HOUR]  = twodigits(buffer, 8);
596 	clkregs[MC_DOM]   = twodigits(buffer, 6);
597 	clkregs[MC_MONTH] = twodigits(buffer, 4);
598 	s = twodigits(buffer, 0) * 100 + twodigits(buffer, 2);
599 	clkregs[MC_YEAR]  = s - GEMSTARTOFTIME;
600 
601 	s = splclock();
602 	MC146818_PUTTOD(RTC, &clkregs);
603 	splx(s);
604 
605 	return(0);
606 }
607