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kern_todr.c revision 1.4
      1 /*	$NetBSD: kern_todr.c,v 1.4 2006/09/03 17:13:04 gdamore 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 1.4 2006/09/03 17:13:04 gdamore Exp $");
     80 
     81 #include <sys/param.h>
     82 
     83 #ifdef	__HAVE_GENERIC_TODR
     84 
     85 #include <sys/kernel.h>
     86 #include <sys/systm.h>
     87 #include <sys/device.h>
     88 #include <sys/timetc.h>
     89 #include <dev/clock_subr.h>	/* hmm.. this should probably move to sys */
     90 
     91 static todr_chip_handle_t todr_handle = NULL;
     92 
     93 /*
     94  * Attach the clock device to todr_handle.
     95  */
     96 void
     97 todr_attach(todr_chip_handle_t todr)
     98 {
     99 
    100         if (todr_handle) {
    101                 printf("todr_attach: TOD already configured\n");
    102 		return;
    103 	}
    104         todr_handle = todr;
    105 }
    106 
    107 static int timeset = 0;
    108 
    109 /*
    110  * Set up the system's time, given a `reasonable' time value.
    111  */
    112 void
    113 inittodr(time_t base)
    114 {
    115 	int badbase = 0, waszero = base == 0, goodtime = 0, badrtc = 0;
    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 	if ((todr_handle == NULL) ||
    142 	    (todr_gettime(todr_handle, &tv) != 0) ||
    143 	    (tv.tv_sec < (5 * SECYR))) {
    144 
    145 		if (todr_handle != NULL)
    146 			printf("WARNING: preposterous TOD clock time\n");
    147 		else
    148 			printf("WARNING: no TOD clock present\n");
    149 		badrtc = 1;
    150 	} else {
    151 		int deltat = tv.tv_sec - base;
    152 
    153 		if (deltat < 0)
    154 			deltat = -deltat;
    155 
    156 		if ((badbase == 0) && deltat >= 2 * SECDAY) {
    157 
    158 			if (tv.tv_sec < base) {
    159 				/*
    160 				 * The clock should never go backwards
    161 				 * relative to filesystem time.  If it
    162 				 * does by more than the threshold,
    163 				 * believe the filesystem.
    164 				 */
    165 				printf("WARNING: clock lost %d days\n",
    166 				    deltat / SECDAY);
    167 				badrtc = 1;
    168 			}
    169 			else {
    170 				printf("WARNING: clock gained %d days\n",
    171 				    deltat / SECDAY);
    172 			}
    173 		} else {
    174 			goodtime = 1;
    175 		}
    176 	}
    177 
    178 	/* if the rtc time is bad, use the filesystem time */
    179 	if (badrtc) {
    180 		if (badbase) {
    181 			printf("WARNING: using default initial time\n");
    182 		} else {
    183 			printf("WARNING: using filesystem time\n");
    184 		}
    185 		tv.tv_sec = base;
    186 		tv.tv_usec = 0;
    187 	}
    188 
    189 	timeset = 1;
    190 
    191 #ifdef	__HAVE_TIMECOUNTER
    192 	ts.tv_sec = tv.tv_sec;
    193 	ts.tv_nsec = tv.tv_usec * 1000;
    194 	tc_setclock(&ts);
    195 #else
    196 	time = tv;
    197 #endif
    198 
    199 	if (waszero || goodtime)
    200 		return;
    201 
    202 
    203 	printf("WARNING: CHECK AND RESET THE DATE!\n");
    204 
    205 }
    206 
    207 /*
    208  * Reset the TODR based on the time value; used when the TODR
    209  * has a preposterous value and also when the time is reset
    210  * by the stime system call.  Also called when the TODR goes past
    211  * TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight)
    212  * to wrap the TODR around.
    213  */
    214 void
    215 resettodr(void)
    216 {
    217 #ifdef	__HAVE_TIMECOUNTER
    218 	struct timeval	time;
    219 #endif
    220 
    221 	/*
    222 	 * We might have been called by boot() due to a crash early
    223 	 * on.  Don't reset the clock chip if we don't know what time
    224 	 * it is.
    225 	 */
    226 	if (!timeset)
    227 		return;
    228 
    229 #ifdef	__HAVE_TIMECOUNTER
    230 	getmicrotime(&time);
    231 #endif
    232 
    233 	if (time.tv_sec == 0)
    234 		return;
    235 
    236 	if (todr_handle)
    237 		if (todr_settime(todr_handle, &time) != 0)
    238 			printf("Cannot set TOD clock time\n");
    239 }
    240 
    241 #endif	/* __HAVE_GENERIC_TODR */
    242