xref: /titanic_41/usr/src/uts/i86pc/io/todpc_subr.c (revision 2a8d6eba033e4713ab12b61178f0513f1f075482)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1990, 1991 UNIX System Laboratories, Inc.	*/
28 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T	*/
29 /*	  All Rights Reserved  	*/
30 
31 /*	Copyright (c) 1987, 1988 Microsoft Corporation	*/
32 /*	  All Rights Reserved	*/
33 
34 #include <sys/param.h>
35 #include <sys/time.h>
36 #include <sys/systm.h>
37 
38 #include <sys/cpuvar.h>
39 #include <sys/clock.h>
40 #include <sys/debug.h>
41 #include <sys/rtc.h>
42 #include <sys/archsystm.h>
43 #include <sys/sysmacros.h>
44 #include <sys/lockstat.h>
45 #include <sys/stat.h>
46 #include <sys/sunddi.h>
47 
48 #include <sys/acpi/acpi.h>
49 #include <sys/acpica.h>
50 
51 static int todpc_rtcget(unsigned char *buf);
52 static void todpc_rtcput(unsigned char *buf);
53 
54 #define	CLOCK_RES	1000		/* 1 microsec in nanosecs */
55 
56 int clock_res = CLOCK_RES;
57 
58 /*
59  * The minimum sleep time till an alarm can be fired.
60  * This can be tuned in /etc/system, but if the value is too small,
61  * there is a danger that it will be missed if it takes too long to
62  * get from the set point to sleep.  Or that it can fire quickly, and
63  * generate a power spike on the hardware.  And small values are
64  * probably only usefull for test setups.
65  */
66 int clock_min_alarm = 4;
67 
68 /*
69  * Machine-dependent clock routines.
70  */
71 
72 extern long gmt_lag;
73 
74 struct rtc_offset {
75 	int8_t	loaded;
76 	uint8_t	day_alrm;
77 	uint8_t mon_alrm;
78 	uint8_t	century;
79 };
80 
81 static struct rtc_offset pc_rtc_offset = {0, 0, 0, 0};
82 
83 
84 /*
85  * Entry point for ACPI to pass RTC or other clock values that
86  * are useful to TOD.
87  */
88 void
89 pc_tod_set_rtc_offsets(ACPI_TABLE_FADT *fadt) {
90 	int		ok = 0;
91 
92 	/*
93 	 * ASSERT is for debugging, but we don't want the machine
94 	 * falling over because for some reason we didn't get a valid
95 	 * pointer.
96 	 */
97 	ASSERT(fadt);
98 	if (fadt == NULL) {
99 		return;
100 	}
101 
102 	if (fadt->DayAlarm) {
103 		pc_rtc_offset.day_alrm = fadt->DayAlarm;
104 		ok = 1;
105 	}
106 
107 	if (fadt->MonthAlarm) {
108 		pc_rtc_offset.mon_alrm = fadt->MonthAlarm;
109 		ok = 1;
110 	}
111 
112 	if (fadt->Century) {
113 		pc_rtc_offset.century = fadt->Century;
114 		ok = 1;
115 	}
116 
117 	pc_rtc_offset.loaded = ok;
118 }
119 
120 
121 /*
122  * Write the specified time into the clock chip.
123  * Must be called with tod_lock held.
124  */
125 /*ARGSUSED*/
126 static void
127 todpc_set(tod_ops_t *top, timestruc_t ts)
128 {
129 	todinfo_t tod = utc_to_tod(ts.tv_sec - ggmtl());
130 	struct rtc_t rtc;
131 
132 	ASSERT(MUTEX_HELD(&tod_lock));
133 
134 	if (todpc_rtcget((unsigned char *)&rtc))
135 		return;
136 
137 	/*
138 	 * rtc bytes are in binary-coded decimal, so we have to convert.
139 	 * We assume that we wrap the rtc year back to zero at 2000.
140 	 */
141 	/* LINTED: YRBASE = 0 for x86 */
142 	tod.tod_year -= YRBASE;
143 	if (tod.tod_year >= 100) {
144 		tod.tod_year -= 100;
145 		rtc.rtc_century = BYTE_TO_BCD(20); /* 20xx year */
146 	} else
147 		rtc.rtc_century = BYTE_TO_BCD(19); /* 19xx year */
148 	rtc.rtc_yr	= BYTE_TO_BCD(tod.tod_year);
149 	rtc.rtc_mon	= BYTE_TO_BCD(tod.tod_month);
150 	rtc.rtc_dom	= BYTE_TO_BCD(tod.tod_day);
151 	/* dow < 10, so no conversion */
152 	rtc.rtc_dow	= (unsigned char)tod.tod_dow;
153 	rtc.rtc_hr	= BYTE_TO_BCD(tod.tod_hour);
154 	rtc.rtc_min	= BYTE_TO_BCD(tod.tod_min);
155 	rtc.rtc_sec	= BYTE_TO_BCD(tod.tod_sec);
156 
157 	todpc_rtcput((unsigned char *)&rtc);
158 }
159 
160 /*
161  * Read the current time from the clock chip and convert to UNIX form.
162  * Assumes that the year in the clock chip is valid.
163  * Must be called with tod_lock held.
164  */
165 /*ARGSUSED*/
166 static timestruc_t
167 todpc_get(tod_ops_t *top)
168 {
169 	timestruc_t ts;
170 	todinfo_t tod;
171 	struct rtc_t rtc;
172 	int compute_century;
173 	static int century_warn = 1; /* only warn once, not each time called */
174 	static int range_warn = 1;
175 
176 	ASSERT(MUTEX_HELD(&tod_lock));
177 
178 	if (todpc_rtcget((unsigned char *)&rtc)) {
179 		ts.tv_sec = 0;
180 		ts.tv_nsec = 0;
181 		tod_fault_reset();
182 		return (ts);
183 	}
184 
185 	/* assume that we wrap the rtc year back to zero at 2000 */
186 	tod.tod_year	= BCD_TO_BYTE(rtc.rtc_yr);
187 	if (tod.tod_year < 69) {
188 		if (range_warn && tod.tod_year > 38) {
189 			cmn_err(CE_WARN, "hardware real-time clock is out "
190 			    "of range -- time needs to be reset");
191 			range_warn = 0;
192 		}
193 		tod.tod_year += 100 + YRBASE; /* 20xx year */
194 		compute_century = 20;
195 	} else {
196 		/* LINTED: YRBASE = 0 for x86 */
197 		tod.tod_year += YRBASE; /* 19xx year */
198 		compute_century = 19;
199 	}
200 	if (century_warn && BCD_TO_BYTE(rtc.rtc_century) != compute_century) {
201 		cmn_err(CE_NOTE,
202 		    "The hardware real-time clock appears to have the "
203 		    "wrong century: %d.\nSolaris will still operate "
204 		    "correctly, but other OS's/firmware agents may "
205 		    "not.\nUse date(1) to set the date to the current "
206 		    "time to correct the RTC.",
207 		    BCD_TO_BYTE(rtc.rtc_century));
208 		century_warn = 0;
209 	}
210 	tod.tod_month	= BCD_TO_BYTE(rtc.rtc_mon);
211 	tod.tod_day	= BCD_TO_BYTE(rtc.rtc_dom);
212 	tod.tod_dow	= rtc.rtc_dow;	/* dow < 10, so no conversion needed */
213 	tod.tod_hour	= BCD_TO_BYTE(rtc.rtc_hr);
214 	tod.tod_min	= BCD_TO_BYTE(rtc.rtc_min);
215 	tod.tod_sec	= BCD_TO_BYTE(rtc.rtc_sec);
216 
217 	ts.tv_sec = tod_to_utc(tod) + ggmtl();
218 	ts.tv_nsec = 0;
219 
220 	return (ts);
221 }
222 
223 #include <sys/promif.h>
224 /*
225  * Write the specified wakeup alarm into the clock chip.
226  * Must be called with tod_lock held.
227  */
228 void
229 /*ARGSUSED*/
230 todpc_setalarm(tod_ops_t *top, int nsecs)
231 {
232 	struct rtc_t rtc;
233 	int delta, asec, amin, ahr, adom, amon;
234 	int day_alrm = pc_rtc_offset.day_alrm;
235 	int mon_alrm = pc_rtc_offset.mon_alrm;
236 
237 	ASSERT(MUTEX_HELD(&tod_lock));
238 
239 	/* A delay of zero is not allowed */
240 	if (nsecs == 0)
241 		return;
242 
243 	/* Make sure that we delay no less than the minimum time */
244 	if (nsecs < clock_min_alarm)
245 		nsecs = clock_min_alarm;
246 
247 	if (todpc_rtcget((unsigned char *)&rtc))
248 		return;
249 
250 	/*
251 	 * Compute alarm secs, mins and hrs, and where appropriate, dom
252 	 * and mon.  rtc bytes are in binary-coded decimal, so we have
253 	 * to convert.
254 	 */
255 	delta = nsecs + BCD_TO_BYTE(rtc.rtc_sec);
256 	asec = delta % 60;
257 
258 	delta = (delta / 60) + BCD_TO_BYTE(rtc.rtc_min);
259 	amin = delta % 60;
260 
261 	delta = (delta / 60) + BCD_TO_BYTE(rtc.rtc_hr);
262 	ahr  = delta % 24;
263 
264 	if (day_alrm == 0 && delta >= 24) {
265 		prom_printf("No day alarm - set to end of today!\n");
266 		asec = 59;
267 		amin = 59;
268 		ahr  = 23;
269 	} else {
270 		int mon = BCD_TO_BYTE(rtc.rtc_mon);
271 		static int dpm[] =
272 		    {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
273 
274 		adom = (delta / 24) + BCD_TO_BYTE(rtc.rtc_dom);
275 
276 		if (mon_alrm == 0) {
277 			if (adom > dpm[mon]) {
278 				prom_printf("No mon alarm - "
279 				    "set to end of current month!\n");
280 				asec = 59;
281 				amin = 59;
282 				ahr  = 23;
283 				adom = dpm[mon];
284 			}
285 		} else {
286 			for (amon = mon;
287 			    amon <= 12 && adom > dpm[amon]; amon++) {
288 				adom -= dpm[amon];
289 			}
290 			if (amon > 12) {
291 				prom_printf("Alarm too far in future - "
292 				    "set to end of current year!\n");
293 				asec = 59;
294 				amin = 59;
295 				ahr  = 23;
296 				adom = dpm[12];
297 				amon = 12;
298 			}
299 			rtc.rtc_amon = BYTE_TO_BCD(amon);
300 		}
301 
302 		rtc.rtc_adom = BYTE_TO_BCD(adom);
303 	}
304 
305 	rtc.rtc_asec = BYTE_TO_BCD(asec);
306 	rtc.rtc_amin = BYTE_TO_BCD(amin);
307 	rtc.rtc_ahr  = BYTE_TO_BCD(ahr);
308 
309 	rtc.rtc_statusb |= RTC_AIE;	/* Enable alarm interrupt */
310 
311 	todpc_rtcput((unsigned char *)&rtc);
312 }
313 
314 /*
315  * Clear an alarm.  This is effectively setting an alarm of 0.
316  */
317 void
318 /*ARGSUSED*/
319 todpc_clralarm(tod_ops_t *top)
320 {
321 	mutex_enter(&tod_lock);
322 	todpc_setalarm(top, 0);
323 	mutex_exit(&tod_lock);
324 }
325 
326 /*
327  * Routine to read contents of real time clock to the specified buffer.
328  * Returns ENXIO if clock not valid, or EAGAIN if clock data cannot be read
329  * else 0.
330  * The routine will busy wait for the Update-In-Progress flag to clear.
331  * On completion of the reads the Seconds register is re-read and the
332  * UIP flag is rechecked to confirm that an clock update did not occur
333  * during the accesses.  Routine will error exit after 256 attempts.
334  * (See bugid 1158298.)
335  * Routine returns RTC_NREG (which is 15) bytes of data, as given in the
336  * technical reference.  This data includes both time and status registers.
337  */
338 
339 static int
340 todpc_rtcget(unsigned char *buf)
341 {
342 	unsigned char	reg;
343 	int		i;
344 	int		retries = 256;
345 	unsigned char	*rawp;
346 	unsigned char	century = RTC_CENTURY;
347 	unsigned char	day_alrm;
348 	unsigned char	mon_alrm;
349 
350 	ASSERT(MUTEX_HELD(&tod_lock));
351 
352 	day_alrm = pc_rtc_offset.day_alrm;
353 	mon_alrm = pc_rtc_offset.mon_alrm;
354 	if (pc_rtc_offset.century != 0) {
355 		century = pc_rtc_offset.century;
356 	}
357 
358 	outb(RTC_ADDR, RTC_D);		/* check if clock valid */
359 	reg = inb(RTC_DATA);
360 	if ((reg & RTC_VRT) == 0)
361 		return (ENXIO);
362 
363 checkuip:
364 	if (retries-- < 0)
365 		return (EAGAIN);
366 	outb(RTC_ADDR, RTC_A);		/* check if update in progress */
367 	reg = inb(RTC_DATA);
368 	if (reg & RTC_UIP) {
369 		tenmicrosec();
370 		goto checkuip;
371 	}
372 
373 	for (i = 0, rawp = buf; i < RTC_NREG; i++) {
374 		outb(RTC_ADDR, i);
375 		*rawp++ = inb(RTC_DATA);
376 	}
377 	outb(RTC_ADDR, century); /* do century */
378 	((struct rtc_t *)buf)->rtc_century = inb(RTC_DATA);
379 
380 	if (day_alrm > 0) {
381 		outb(RTC_ADDR, day_alrm);
382 		((struct rtc_t *)buf)->rtc_adom = inb(RTC_DATA) & 0x3f;
383 	}
384 	if (mon_alrm > 0) {
385 		outb(RTC_ADDR, mon_alrm);
386 		((struct rtc_t *)buf)->rtc_amon = inb(RTC_DATA);
387 	}
388 
389 	outb(RTC_ADDR, 0);		/* re-read Seconds register */
390 	reg = inb(RTC_DATA);
391 	if (reg != ((struct rtc_t *)buf)->rtc_sec ||
392 	    (((struct rtc_t *)buf)->rtc_statusa & RTC_UIP))
393 		/* update occured during reads */
394 		goto checkuip;
395 
396 	return (0);
397 }
398 
399 /*
400  * This routine writes the contents of the given buffer to the real time
401  * clock.  It is given RTC_NREGP bytes of data, which are the 10 bytes used
402  * to write the time and set the alarm.  It should be called with the priority
403  * raised to 5.
404  */
405 static void
406 todpc_rtcput(unsigned char *buf)
407 {
408 	unsigned char	reg;
409 	int		i;
410 	unsigned char	century = RTC_CENTURY;
411 	unsigned char	day_alrm = pc_rtc_offset.day_alrm;
412 	unsigned char	mon_alrm = pc_rtc_offset.mon_alrm;
413 	unsigned char	tmp;
414 
415 	if (pc_rtc_offset.century != 0) {
416 		century = pc_rtc_offset.century;
417 	}
418 
419 	outb(RTC_ADDR, RTC_B);
420 	reg = inb(RTC_DATA);
421 	outb(RTC_ADDR, RTC_B);
422 	outb(RTC_DATA, reg | RTC_SET);	/* allow time set now */
423 	for (i = 0; i < RTC_NREGP; i++) { /* set the time */
424 		outb(RTC_ADDR, i);
425 		outb(RTC_DATA, buf[i]);
426 	}
427 	outb(RTC_ADDR, century); /* do century */
428 	outb(RTC_DATA, ((struct rtc_t *)buf)->rtc_century);
429 
430 	if (day_alrm > 0) {
431 		outb(RTC_ADDR, day_alrm);
432 		/* preserve RTC_VRT bit; some virt envs accept writes there */
433 		tmp = inb(RTC_DATA) & RTC_VRT;
434 		tmp |= ((struct rtc_t *)buf)->rtc_adom & ~RTC_VRT;
435 		outb(RTC_DATA, tmp);
436 	}
437 	if (mon_alrm > 0) {
438 		outb(RTC_ADDR, mon_alrm);
439 		outb(RTC_DATA, ((struct rtc_t *)buf)->rtc_amon);
440 	}
441 
442 	outb(RTC_ADDR, RTC_B);
443 	reg = inb(RTC_DATA);
444 	outb(RTC_ADDR, RTC_B);
445 	outb(RTC_DATA, reg & ~RTC_SET);	/* allow time update */
446 }
447 
448 static tod_ops_t todpc_ops = {
449 	TOD_OPS_VERSION,
450 	todpc_get,
451 	todpc_set,
452 	NULL,
453 	NULL,
454 	todpc_setalarm,
455 	todpc_clralarm,
456 	NULL
457 };
458 
459 /*
460  * Initialize for the default TOD ops vector for use on hardware.
461  */
462 
463 tod_ops_t *tod_ops = &todpc_ops;
464