xref: /netbsd-src/sys/kern/kern_todr.c (revision 0df165c04d0a9ca1adde9ed2b890344c937954a6)
1 /*	$NetBSD: kern_todr.c,v 1.24 2006/09/24 18:24:55 peter Exp $	*/
2 
3 /*
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  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 and Ralph Campbell.
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	8.1 (Berkeley) 6/10/93
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 and Ralph Campbell.
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	8.1 (Berkeley) 6/10/93
77  */
78 #include <sys/cdefs.h>
79 __KERNEL_RCSID(0, "$NetBSD: kern_todr.c,v 1.24 2006/09/24 18:24:55 peter Exp $");
80 
81 #include <sys/param.h>
82 #include <sys/kernel.h>
83 #include <sys/systm.h>
84 #include <sys/device.h>
85 #include <sys/timetc.h>
86 #include <dev/clock_subr.h>	/* hmm.. this should probably move to sys */
87 
88 #ifdef	__HAVE_GENERIC_TODR
89 
90 static todr_chip_handle_t todr_handle = NULL;
91 
92 /*
93  * Attach the clock device to todr_handle.
94  */
95 void
96 todr_attach(todr_chip_handle_t todr)
97 {
98 
99 	if (todr_handle) {
100 		printf("todr_attach: TOD already configured\n");
101 		return;
102 	}
103 	todr_handle = todr;
104 }
105 
106 static int timeset = 0;
107 
108 /*
109  * Set up the system's time, given a `reasonable' time value.
110  */
111 void
112 inittodr(time_t base)
113 {
114 	int badbase = 0, waszero = (base == 0), goodtime = 0, badrtc = 0;
115 	int s;
116 #ifdef	__HAVE_TIMECOUNTER
117 	struct timespec ts;
118 #endif
119 	struct timeval tv;
120 
121 	if (base < 5 * SECYR) {
122 		struct clock_ymdhms basedate;
123 
124 		/*
125 		 * If base is 0, assume filesystem time is just unknown
126 		 * instead of preposterous. Don't bark.
127 		 */
128 		if (base != 0)
129 			printf("WARNING: preposterous time in file system\n");
130 		/* not going to use it anyway, if the chip is readable */
131 		basedate.dt_year = 2006;
132 		basedate.dt_mon = 1;
133 		basedate.dt_day = 1;
134 		basedate.dt_hour = 12;
135 		basedate.dt_min = 0;
136 		basedate.dt_sec = 0;
137 		base = clock_ymdhms_to_secs(&basedate);
138 		badbase = 1;
139 	}
140 
141 	/*
142 	 * Some ports need to be supplied base in order to fabricate a time_t.
143 	 */
144 	if (todr_handle)
145 		todr_handle->base_time = base;
146 
147 	if ((todr_handle == NULL) ||
148 	    (todr_gettime(todr_handle, &tv) != 0) ||
149 	    (tv.tv_sec < (25 * SECYR))) {
150 
151 		if (todr_handle != NULL)
152 			printf("WARNING: preposterous TOD clock time\n");
153 		else
154 			printf("WARNING: no TOD clock present\n");
155 		badrtc = 1;
156 	} else {
157 		int deltat = tv.tv_sec - base;
158 
159 		if (deltat < 0)
160 			deltat = -deltat;
161 
162 		if ((badbase == 0) && deltat >= 2 * SECDAY) {
163 
164 			if (tv.tv_sec < base) {
165 				/*
166 				 * The clock should never go backwards
167 				 * relative to filesystem time.  If it
168 				 * does by more than the threshold,
169 				 * believe the filesystem.
170 				 */
171 				printf("WARNING: clock lost %d days\n",
172 				    deltat / SECDAY);
173 				badrtc = 1;
174 			} else {
175 				printf("WARNING: clock gained %d days\n",
176 				    deltat / SECDAY);
177 			}
178 		} else {
179 			goodtime = 1;
180 		}
181 	}
182 
183 	/* if the rtc time is bad, use the filesystem time */
184 	if (badrtc) {
185 		if (badbase) {
186 			printf("WARNING: using default initial time\n");
187 		} else {
188 			printf("WARNING: using filesystem time\n");
189 		}
190 		tv.tv_sec = base;
191 		tv.tv_usec = 0;
192 	}
193 
194 	timeset = 1;
195 
196 	s = splclock();
197 #ifdef	__HAVE_TIMECOUNTER
198 	ts.tv_sec = tv.tv_sec;
199 	ts.tv_nsec = tv.tv_usec * 1000;
200 	tc_setclock(&ts);
201 #else
202 	time = tv;
203 #endif
204 	splx(s);
205 
206 	if (waszero || goodtime)
207 		return;
208 
209 	printf("WARNING: CHECK AND RESET THE DATE!\n");
210 }
211 
212 /*
213  * Reset the TODR based on the time value; used when the TODR
214  * has a preposterous value and also when the time is reset
215  * by the stime system call.  Also called when the TODR goes past
216  * TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight)
217  * to wrap the TODR around.
218  */
219 void
220 resettodr(void)
221 {
222 #ifdef	__HAVE_TIMECOUNTER
223 	struct timeval	time;
224 #endif
225 
226 	/*
227 	 * We might have been called by boot() due to a crash early
228 	 * on.  Don't reset the clock chip if we don't know what time
229 	 * it is.
230 	 */
231 	if (!timeset)
232 		return;
233 
234 #ifdef	__HAVE_TIMECOUNTER
235 	getmicrotime(&time);
236 #endif
237 
238 	if (time.tv_sec == 0)
239 		return;
240 
241 	if (todr_handle)
242 		if (todr_settime(todr_handle, &time) != 0)
243 			printf("Cannot set TOD clock time\n");
244 }
245 
246 #endif	/* __HAVE_GENERIC_TODR */
247 
248 #ifdef	TODR_DEBUG
249 static void
250 todr_debug(const char *prefix, int rv, struct clock_ymdhms *dt,
251     volatile struct timeval *tvp)
252 {
253 	struct timeval tv_val;
254 	struct clock_ymdhms dt_val;
255 
256 	if (dt == NULL) {
257 		clock_secs_to_ymdhms(tvp->tv_sec, &dt_val);
258 		dt = &dt_val;
259 	}
260 	if (tvp == NULL) {
261 		tvp = &tv_val;
262 		tvp->tv_sec = clock_ymdhms_to_secs(dt);
263 		tvp->tv_usec = 0;
264 	}
265 	printf("%s: rv = %d\n", prefix, rv);
266 	printf("%s: rtc_offset = %d\n", prefix, rtc_offset);
267 	printf("%s: %4u/%02u/%02u %02u:%02u:%02u, (wday %d) (epoch %u.%06u)\n",
268 	    prefix,
269 	    dt->dt_year, dt->dt_mon, dt->dt_day,
270 	    dt->dt_hour, dt->dt_min, dt->dt_sec,
271 	    dt->dt_wday, (unsigned)tvp->tv_sec, (unsigned)tvp->tv_usec);
272 }
273 #else	/* !TODR_DEBUG */
274 #define	todr_debug(prefix, rv, dt, tvp)
275 #endif	/* TODR_DEBUG */
276 
277 
278 int
279 todr_gettime(todr_chip_handle_t tch, volatile struct timeval *tvp)
280 {
281 	struct clock_ymdhms	dt;
282 	int			rv;
283 
284 	if (tch->todr_gettime) {
285 		rv = tch->todr_gettime(tch, tvp);
286 		/*
287 		 * Some unconverted ports have their own references to
288 		 * rtc_offset.   A converted port must not do that.
289 		 */
290 #ifdef	__HAVE_GENERIC_TODR
291 		if (rv == 0)
292 			tvp->tv_sec += rtc_offset * 60;
293 #endif
294 		todr_debug("TODR-GET-SECS", rv, NULL, tvp);
295 		return rv;
296 	} else if (tch->todr_gettime_ymdhms) {
297 		rv = tch->todr_gettime_ymdhms(tch, &dt);
298 		todr_debug("TODR-GET-YMDHMS", rv, &dt, NULL);
299 		if (rv)
300 			return rv;
301 
302 		/*
303 		 * Formerly we had code here that explicitly checked
304 		 * for 2038 year rollover.
305 		 *
306 		 * However, clock_ymdhms_to_secs performs the same
307 		 * check for us, so we need not worry about it.  Note
308 		 * that this assumes that the tvp->tv_sec member is
309 		 * a time_t.
310 		 */
311 
312 		/*
313 		 * Simple sanity checks.  Note that this includes a
314 		 * value for clocks that can return a leap second.
315 		 * Note that we don't support double leap seconds,
316 		 * since this was apparently an error/misunderstanding
317 		 * on the part of the ISO C committee, and can never
318 		 * actually occur.  If your clock issues us a double
319 		 * leap second, it must be broken.  Ultimately, you'd
320 		 * have to be trying to read time at precisely that
321 		 * instant to even notice, so even broken clocks will
322 		 * work the vast majority of the time.  In such a case
323 		 * it is recommended correction be applied in the
324 		 * clock driver.
325 		 */
326 		if (dt.dt_mon < 1 || dt.dt_mon > 12 ||
327 		    dt.dt_day < 1 || dt.dt_day > 31 ||
328 		    dt.dt_hour > 23 || dt.dt_min > 59 || dt.dt_sec > 60) {
329 			return EINVAL;
330 		}
331 		tvp->tv_sec = clock_ymdhms_to_secs(&dt) + rtc_offset * 60;
332 		tvp->tv_usec = 0;
333 		return tvp->tv_sec < 0 ? EINVAL : 0;
334 	}
335 
336 	return ENXIO;
337 }
338 
339 int
340 todr_settime(todr_chip_handle_t tch, volatile struct timeval *tvp)
341 {
342 	struct clock_ymdhms	dt;
343 	int			rv;
344 
345 	if (tch->todr_settime) {
346 		/* See comments above in gettime why this is ifdef'd */
347 #ifdef	__HAVE_GENERIC_TODR
348 		struct timeval	copy = *tvp;
349 		copy.tv_sec -= rtc_offset * 60;
350 		rv = tch->todr_settime(tch, &copy);
351 #else
352 		rv = tch->todr_settime(tch, tvp);
353 #endif
354 		todr_debug("TODR-SET-SECS", rv, NULL, tvp);
355 		return rv;
356 	} else if (tch->todr_settime_ymdhms) {
357 		time_t	sec = tvp->tv_sec - rtc_offset * 60;
358 		if (tvp->tv_usec >= 500000)
359 			sec++;
360 		clock_secs_to_ymdhms(sec, &dt);
361 		rv = tch->todr_settime_ymdhms(tch, &dt);
362 		todr_debug("TODR-SET-YMDHMS", rv, &dt, NULL);
363 		return rv;
364 	} else {
365 		return ENXIO;
366 	}
367 }
368