1 /* $NetBSD: clock.c,v 1.1.1.1 1995/07/25 23:12:28 chuck Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * Copyright (c) 1994 Gordon W. Ross 7 * Copyright (c) 1993 Adam Glass 8 * 9 * This software was developed by the Computer Systems Engineering group 10 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 11 * contributed to Berkeley. 12 * 13 * All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Lawrence Berkeley Laboratory. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 3. All advertising materials mentioning features or use of this software 27 * must display the following acknowledgement: 28 * This product includes software developed by the University of 29 * California, Berkeley and its contributors. 30 * 4. Neither the name of the University nor the names of its contributors 31 * may be used to endorse or promote products derived from this software 32 * without specific prior written permission. 33 * 34 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 35 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 36 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 37 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 38 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 39 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 40 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 41 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 42 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 43 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 44 * SUCH DAMAGE. 45 * 46 * @(#)clock.c 8.1 (Berkeley) 6/11/93 47 */ 48 49 /* 50 * Clock driver. 51 */ 52 53 #include "sboot.h" 54 #include "clockreg.h" 55 static struct clockreg *clockreg = (struct clockreg *) CLOCK_ADDR; 56 57 /* 58 * BCD to decimal and decimal to BCD. 59 */ 60 #define FROMBCD(x) (((x) >> 4) * 10 + ((x) & 0xf)) 61 #define TOBCD(x) (((x) / 10 * 16) + ((x) % 10)) 62 63 #define SECDAY (24 * 60 * 60) 64 #define SECYR (SECDAY * 365) 65 #define LEAPYEAR(y) (((y) & 3) == 0) 66 67 /* 68 * This code is defunct after 2068. 69 * Will Unix still be here then?? 70 */ 71 const short dayyr[12] = 72 { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; 73 74 static u_long chiptotime(sec, min, hour, day, mon, year) 75 register int sec, min, hour, day, mon, year; 76 { 77 register int days, yr; 78 79 sec = FROMBCD(sec); 80 min = FROMBCD(min); 81 hour = FROMBCD(hour); 82 day = FROMBCD(day); 83 mon = FROMBCD(mon); 84 year = FROMBCD(year) + YEAR0; 85 if (year < 70) year = 70; 86 87 /* simple sanity checks */ 88 if (year < 70 || mon < 1 || mon > 12 || day < 1 || day > 31) 89 return (0); 90 days = 0; 91 for (yr = 70; yr < year; yr++) 92 days += LEAPYEAR(yr) ? 366 : 365; 93 days += dayyr[mon - 1] + day - 1; 94 if (LEAPYEAR(yr) && mon > 2) 95 days++; 96 /* now have days since Jan 1, 1970; the rest is easy... */ 97 return (days * SECDAY + hour * 3600 + min * 60 + sec); 98 } 99 100 /* 101 * Set up the system's time, given a `reasonable' time value. 102 */ 103 u_long time() 104 { 105 register struct clockreg *cl = clockreg; 106 int sec, min, hour, day, mon, year; 107 108 cl->cl_csr |= CLK_READ; /* enable read (stop time) */ 109 sec = cl->cl_sec; 110 min = cl->cl_min; 111 hour = cl->cl_hour; 112 day = cl->cl_mday; 113 mon = cl->cl_month; 114 year = cl->cl_year; 115 cl->cl_csr &= ~CLK_READ; /* time wears on */ 116 return(chiptotime(sec, min, hour, day, mon, year)); 117 } 118