1 /* $NetBSD: clock.c,v 1.16 2002/01/31 17:57:43 uch Exp $ */ 2 3 /*- 4 * Copyright (c) 1999 Shin Takemura, All rights reserved. 5 * Copyright (c) 1999-2001 SATO Kazumi, All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 /* 33 * Copyright (c) 1988 University of Utah. 34 * Copyright (c) 1992, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * This code is derived from software contributed to Berkeley by 38 * the Systems Programming Group of the University of Utah Computer 39 * Science Department and Ralph Campbell. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 3. All advertising materials mentioning features or use of this software 50 * must display the following acknowledgement: 51 * This product includes software developed by the University of 52 * California, Berkeley and its contributors. 53 * 4. Neither the name of the University nor the names of its contributors 54 * may be used to endorse or promote products derived from this software 55 * without specific prior written permission. 56 * 57 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 58 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 59 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 60 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 61 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 62 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 63 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 64 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 65 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 66 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 67 * SUCH DAMAGE. 68 * 69 * from: Utah Hdr: clock.c 1.18 91/01/21 70 * 71 * @(#)clock.c 8.1 (Berkeley) 6/10/93 72 */ 73 74 #include <sys/cdefs.h> /* RCS ID & Copyright macro defns */ 75 __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.16 2002/01/31 17:57:43 uch Exp $"); 76 77 #include <sys/param.h> 78 #include <sys/systm.h> 79 #include <sys/kernel.h> /* hz */ 80 81 #include <dev/clock_subr.h> 82 #include <machine/sysconf.h> /* platform */ 83 84 #define MINYEAR 2002 /* "today" */ 85 #define UNIX_YEAR_OFFSET 0 86 87 /* 88 * platform_clock_attach: 89 * 90 * Register CPU(VR41XX or TX39XX) dependent clock routine to system. 91 */ 92 void 93 platform_clock_attach(void *ctx, struct platform_clock *clock) 94 { 95 96 printf("\n"); 97 98 clock->self = ctx; 99 platform.clock = clock; 100 } 101 102 /* 103 * cpu_initclocks: 104 * 105 * starts periodic timer, which provides hardclock interrupts to 106 * kern_clock.c. 107 * Leave stathz 0 since there are no other timers available. 108 */ 109 void 110 cpu_initclocks() 111 { 112 struct platform_clock *clock = platform.clock; 113 114 if (clock == NULL) 115 panic("cpu_initclocks: no clock attached"); 116 117 hz = clock->hz; 118 tick = 1000000 / hz; 119 /* number of microseconds between interrupts */ 120 tickfix = 1000000 - (hz * tick); 121 if (tickfix) { 122 int ftp; 123 124 ftp = min(ffs(tickfix), ffs(hz)); 125 tickfix >>= (ftp - 1); 126 tickfixinterval = hz >> (ftp - 1); 127 } 128 129 /* start periodic timer */ 130 (*clock->init)(clock->self); 131 } 132 133 /* 134 * setstatclockrate: 135 * 136 * We assume newhz is either stathz or profhz, and that neither will 137 * change after being set up above. Could recalculate intervals here 138 * but that would be a drag. 139 */ 140 void 141 setstatclockrate(int newhz) 142 { 143 144 /* nothing we can do */ 145 } 146 147 /* 148 * inittodr: 149 * 150 * initializes the time of day hardware which provides 151 * date functions. Its primary function is to use some file 152 * system information in case the hardare clock lost state. 153 * 154 * Initialze the time of day register, based on the time base which is, 155 * e.g. from a filesystem. Base provides the time to within six months, 156 * and the time of year clock (if any) provides the rest. 157 */ 158 void 159 inittodr(time_t base) 160 { 161 struct platform_clock *clock = platform.clock; 162 struct clock_ymdhms dt; 163 int year, badbase; 164 time_t deltat; 165 166 if (clock == NULL) 167 panic("inittodr: no clock attached"); 168 169 if (base < (MINYEAR - 1970) * SECYR) { 170 printf("WARNING: preposterous time in file system"); 171 /* read the system clock anyway */ 172 base = (MINYEAR - 1970) * SECYR; 173 badbase = 1; 174 } else 175 badbase = 0; 176 177 (*clock->rtc_get)(clock->self, base, &dt); 178 #ifdef DEBUG 179 printf("readclock: %d/%d/%d/%d/%d/%d", dt.dt_year, dt.dt_mon, dt.dt_day, 180 dt.dt_hour, dt.dt_min, dt.dt_sec); 181 #endif 182 clock->start = 1; 183 184 year = 1900 + UNIX_YEAR_OFFSET + dt.dt_year; 185 if (year < 1970) 186 year += 100; 187 /* simple sanity checks (2037 = time_t overflow) */ 188 if (year < MINYEAR || year > 2037 || 189 dt.dt_mon < 1 || dt.dt_mon > 12 || dt.dt_day < 1 || 190 dt.dt_day > 31 || dt.dt_hour > 23 || dt.dt_min > 59 || 191 dt.dt_sec > 59) { 192 /* 193 * Believe the time in the file system for lack of 194 * anything better, resetting the TODR. 195 */ 196 time.tv_sec = base; 197 if (!badbase) { 198 printf("WARNING: preposterous clock chip time\n"); 199 resettodr(); 200 } 201 goto bad; 202 } 203 204 dt.dt_year = year; 205 time.tv_sec = clock_ymdhms_to_secs(&dt); 206 #ifdef DEBUG 207 printf("=>%ld (%ld)\n", time.tv_sec, base); 208 #endif 209 210 if (!badbase) { 211 /* 212 * See if we gained/lost two or more days; 213 * if so, assume something is amiss. 214 */ 215 deltat = time.tv_sec - base; 216 if (deltat < 0) 217 deltat = -deltat; 218 if (deltat < 2 * SECDAY) 219 return; 220 printf("WARNING: clock %s %ld days", 221 time.tv_sec < base ? "lost" : "gained", 222 (long)deltat / SECDAY); 223 } 224 bad: 225 printf(" -- CHECK AND RESET THE DATE!\n"); 226 } 227 228 /* 229 * resettodr: 230 * 231 * restores the time of day hardware after a time change. 232 * 233 * Reset the TODR based on the time value; used when the TODR 234 * has a preposterous value and also when the time is reset 235 * by the stime system call. Also called when the TODR goes past 236 * TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight) 237 * to wrap the TODR around. 238 */ 239 void 240 resettodr() 241 { 242 struct platform_clock *clock = platform.clock; 243 struct clock_ymdhms dt; 244 245 if (clock == NULL) 246 panic("inittodr: no clock attached"); 247 248 if (!clock->start) 249 return; 250 251 clock_secs_to_ymdhms(time.tv_sec, &dt); 252 253 /* rt clock wants 2 digits XXX */ 254 dt.dt_year = (dt.dt_year - UNIX_YEAR_OFFSET) % 100; 255 #ifdef DEBUG 256 printf("setclock: %d/%d/%d/%d/%d/%d\n", dt.dt_year, dt.dt_mon, 257 dt.dt_day, dt.dt_hour, dt.dt_min, dt.dt_sec); 258 #endif 259 260 (*clock->rtc_set)(clock->self, &dt); 261 } 262 263 /* 264 * microtime: 265 * 266 * Return the best possible estimate of the time in the timeval to 267 * which tvp points. We guarantee that the time will be greater than 268 * the value obtained by a previous call. 269 */ 270 void 271 microtime(struct timeval *tvp) 272 { 273 int s = splclock(); 274 static struct timeval lasttime; 275 276 *tvp = time; 277 278 if (tvp->tv_usec >= 1000000) { 279 tvp->tv_usec -= 1000000; 280 tvp->tv_sec++; 281 } 282 283 if (tvp->tv_sec == lasttime.tv_sec && 284 tvp->tv_usec <= lasttime.tv_usec && 285 (tvp->tv_usec = lasttime.tv_usec + 1) >= 1000000) { 286 tvp->tv_sec++; 287 tvp->tv_usec -= 1000000; 288 } 289 lasttime = *tvp; 290 splx(s); 291 } 292 293 /* 294 * delay: 295 * 296 * Wait at least "n" microseconds. 297 */ 298 void 299 delay(int n) 300 { 301 302 DELAY(n); 303 } 304