xref: /netbsd/sys/kern/kern_todr.c (revision 6550d01e)
1 /*	$NetBSD: kern_todr.c,v 1.33 2010/01/02 10:57:35 tsutsui 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 1.33 2010/01/02 10:57:35 tsutsui 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 <sys/intr.h>
87 
88 #include <dev/clock_subr.h>	/* hmm.. this should probably move to sys */
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 bool timeset = false;
107 
108 /*
109  * Set up the system's time, given a `reasonable' time value.
110  */
111 void
112 inittodr(time_t base)
113 {
114 	bool badbase = false;
115 	bool waszero = (base == 0);
116 	bool goodtime = false;
117 	bool badrtc = false;
118 	int s;
119 	struct timespec ts;
120 	struct timeval tv;
121 
122 	if (base < 5 * SECYR) {
123 		struct clock_ymdhms basedate;
124 
125 		/*
126 		 * If base is 0, assume filesystem time is just unknown
127 		 * instead of preposterous. Don't bark.
128 		 */
129 		if (base != 0)
130 			printf("WARNING: preposterous time in file system\n");
131 		/* not going to use it anyway, if the chip is readable */
132 		basedate.dt_year = 2010;
133 		basedate.dt_mon = 1;
134 		basedate.dt_day = 1;
135 		basedate.dt_hour = 12;
136 		basedate.dt_min = 0;
137 		basedate.dt_sec = 0;
138 		base = clock_ymdhms_to_secs(&basedate);
139 		badbase = true;
140 	}
141 
142 	/*
143 	 * Some ports need to be supplied base in order to fabricate a time_t.
144 	 */
145 	if (todr_handle)
146 		todr_handle->base_time = base;
147 
148 	if ((todr_handle == NULL) ||
149 	    (todr_gettime(todr_handle, &tv) != 0) ||
150 	    (tv.tv_sec < (25 * SECYR))) {
151 
152 		if (todr_handle != NULL)
153 			printf("WARNING: preposterous TOD clock time\n");
154 		else
155 			printf("WARNING: no TOD clock present\n");
156 		badrtc = true;
157 	} else {
158 		time_t deltat = tv.tv_sec - base;
159 
160 		if (deltat < 0)
161 			deltat = -deltat;
162 
163 		if (!badbase && deltat >= 2 * SECDAY) {
164 
165 			if (tv.tv_sec < base) {
166 				/*
167 				 * The clock should never go backwards
168 				 * relative to filesystem time.  If it
169 				 * does by more than the threshold,
170 				 * believe the filesystem.
171 				 */
172 				printf("WARNING: clock lost %" PRId64 " days\n",
173 				    deltat / SECDAY);
174 				badrtc = true;
175 			} else {
176 				aprint_verbose("WARNING: clock gained %" PRId64
177 				    " days\n", deltat / SECDAY);
178 				goodtime = true;
179 			}
180 		} else {
181 			goodtime = true;
182 		}
183 	}
184 
185 	/* if the rtc time is bad, use the filesystem time */
186 	if (badrtc) {
187 		if (badbase) {
188 			printf("WARNING: using default initial time\n");
189 		} else {
190 			printf("WARNING: using filesystem time\n");
191 		}
192 		tv.tv_sec = base;
193 		tv.tv_usec = 0;
194 	}
195 
196 	timeset = true;
197 
198 	ts.tv_sec = tv.tv_sec;
199 	ts.tv_nsec = tv.tv_usec * 1000;
200 	s = splclock();
201 	tc_setclock(&ts);
202 	splx(s);
203 
204 	if (waszero || goodtime)
205 		return;
206 
207 	printf("WARNING: CHECK AND RESET THE DATE!\n");
208 }
209 
210 /*
211  * Reset the TODR based on the time value; used when the TODR
212  * has a preposterous value and also when the time is reset
213  * by the stime system call.  Also called when the TODR goes past
214  * TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight)
215  * to wrap the TODR around.
216  */
217 void
218 resettodr(void)
219 {
220 	struct timeval tv;
221 
222 	/*
223 	 * We might have been called by boot() due to a crash early
224 	 * on.  Don't reset the clock chip if we don't know what time
225 	 * it is.
226 	 */
227 	if (!timeset)
228 		return;
229 
230 	getmicrotime(&tv);
231 
232 	if (tv.tv_sec == 0)
233 		return;
234 
235 	if (todr_handle)
236 		if (todr_settime(todr_handle, &tv) != 0)
237 			printf("Cannot set TOD clock time\n");
238 }
239 
240 #ifdef	TODR_DEBUG
241 static void
242 todr_debug(const char *prefix, int rv, struct clock_ymdhms *dt,
243     struct timeval *tvp)
244 {
245 	struct timeval tv_val;
246 	struct clock_ymdhms dt_val;
247 
248 	if (dt == NULL) {
249 		clock_secs_to_ymdhms(tvp->tv_sec, &dt_val);
250 		dt = &dt_val;
251 	}
252 	if (tvp == NULL) {
253 		tvp = &tv_val;
254 		tvp->tv_sec = clock_ymdhms_to_secs(dt);
255 		tvp->tv_usec = 0;
256 	}
257 	printf("%s: rv = %d\n", prefix, rv);
258 	printf("%s: rtc_offset = %d\n", prefix, rtc_offset);
259 	printf("%s: %4u/%02u/%02u %02u:%02u:%02u, (wday %d) (epoch %u.%06u)\n",
260 	    prefix,
261 	    dt->dt_year, dt->dt_mon, dt->dt_day,
262 	    dt->dt_hour, dt->dt_min, dt->dt_sec,
263 	    dt->dt_wday, (unsigned)tvp->tv_sec, (unsigned)tvp->tv_usec);
264 }
265 #else	/* !TODR_DEBUG */
266 #define	todr_debug(prefix, rv, dt, tvp)
267 #endif	/* TODR_DEBUG */
268 
269 
270 int
271 todr_gettime(todr_chip_handle_t tch, struct timeval *tvp)
272 {
273 	struct clock_ymdhms	dt;
274 	int			rv;
275 
276 	if (tch->todr_gettime) {
277 		rv = tch->todr_gettime(tch, tvp);
278 		/*
279 		 * Some unconverted ports have their own references to
280 		 * rtc_offset.   A converted port must not do that.
281 		 */
282 		if (rv == 0)
283 			tvp->tv_sec += rtc_offset * 60;
284 		todr_debug("TODR-GET-SECS", rv, NULL, tvp);
285 		return rv;
286 	} else if (tch->todr_gettime_ymdhms) {
287 		rv = tch->todr_gettime_ymdhms(tch, &dt);
288 		todr_debug("TODR-GET-YMDHMS", rv, &dt, NULL);
289 		if (rv)
290 			return rv;
291 
292 		/*
293 		 * Simple sanity checks.  Note that this includes a
294 		 * value for clocks that can return a leap second.
295 		 * Note that we don't support double leap seconds,
296 		 * since this was apparently an error/misunderstanding
297 		 * on the part of the ISO C committee, and can never
298 		 * actually occur.  If your clock issues us a double
299 		 * leap second, it must be broken.  Ultimately, you'd
300 		 * have to be trying to read time at precisely that
301 		 * instant to even notice, so even broken clocks will
302 		 * work the vast majority of the time.  In such a case
303 		 * it is recommended correction be applied in the
304 		 * clock driver.
305 		 */
306 		if (dt.dt_mon < 1 || dt.dt_mon > 12 ||
307 		    dt.dt_day < 1 || dt.dt_day > 31 ||
308 		    dt.dt_hour > 23 || dt.dt_min > 59 || dt.dt_sec > 60) {
309 			return EINVAL;
310 		}
311 		tvp->tv_sec = clock_ymdhms_to_secs(&dt) + rtc_offset * 60;
312 		tvp->tv_usec = 0;
313 		return tvp->tv_sec < 0 ? EINVAL : 0;
314 	}
315 
316 	return ENXIO;
317 }
318 
319 int
320 todr_settime(todr_chip_handle_t tch, struct timeval *tvp)
321 {
322 	struct clock_ymdhms	dt;
323 	int			rv;
324 
325 	if (tch->todr_settime) {
326 		/* See comments above in gettime why this is ifdef'd */
327 		struct timeval	copy = *tvp;
328 		copy.tv_sec -= rtc_offset * 60;
329 		rv = tch->todr_settime(tch, &copy);
330 		todr_debug("TODR-SET-SECS", rv, NULL, tvp);
331 		return rv;
332 	} else if (tch->todr_settime_ymdhms) {
333 		time_t	sec = tvp->tv_sec - rtc_offset * 60;
334 		if (tvp->tv_usec >= 500000)
335 			sec++;
336 		clock_secs_to_ymdhms(sec, &dt);
337 		rv = tch->todr_settime_ymdhms(tch, &dt);
338 		todr_debug("TODR-SET-YMDHMS", rv, &dt, NULL);
339 		return rv;
340 	} else {
341 		return ENXIO;
342 	}
343 }
344