| 1 | /*- |
| 2 | * Copyright (c) 1990 The Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This code is derived from software contributed to Berkeley by |
| 6 | * William Jolitz. |
| 7 | * |
| 8 | * Added stuff to read the cmos clock on startup - Don Ahn |
| 9 | * |
| 10 | * %sccs.include.386.c% |
| 11 | * |
| 12 | * @(#)clock.c 5.3 (Berkeley) %G% |
| 13 | */ |
| 14 | |
| 15 | /* |
| 16 | * Primitive clock interrupt routines. |
| 17 | */ |
| 18 | #include "param.h" |
| 19 | #include "time.h" |
| 20 | #include "kernel.h" |
| 21 | #include "icu.h" |
| 22 | #include "isa.h" |
| 23 | |
| 24 | #define DAYST 119 |
| 25 | #define DAYEN 303 |
| 26 | |
| 27 | startrtclock() { |
| 28 | |
| 29 | /* initialize 8253 clock */ |
| 30 | outb (IO_TIMER0+3, 0x36); |
| 31 | outb (IO_TIMER0, 1193182/hz); |
| 32 | outb (IO_TIMER0, (1193182/hz)/256); |
| 33 | } |
| 34 | |
| 35 | /* convert 2 digit BCD number */ |
| 36 | bcd(i) |
| 37 | int i; |
| 38 | { |
| 39 | return ((i/16)*10 + (i%16)); |
| 40 | } |
| 41 | |
| 42 | /* convert years to seconds (from 1970) */ |
| 43 | unsigned long |
| 44 | ytos(y) |
| 45 | int y; |
| 46 | { |
| 47 | int i; |
| 48 | unsigned long ret; |
| 49 | |
| 50 | ret = 0; y = y - 70; |
| 51 | for(i=0;i<y;i++) { |
| 52 | if (i % 4) ret += 31536000; |
| 53 | else ret += 31622400; |
| 54 | } |
| 55 | return ret; |
| 56 | } |
| 57 | |
| 58 | /* convert months to seconds */ |
| 59 | unsigned long |
| 60 | mtos(m,leap) |
| 61 | int m,leap; |
| 62 | { |
| 63 | int i; |
| 64 | unsigned long ret; |
| 65 | |
| 66 | ret = 0; |
| 67 | for(i=1;i<m;i++) { |
| 68 | switch(i){ |
| 69 | case 1: case 3: case 5: case 7: case 8: case 10: case 12: |
| 70 | ret += 2678400; break; |
| 71 | case 4: case 6: case 9: case 11: |
| 72 | ret += 2592000; break; |
| 73 | case 2: |
| 74 | if (leap) ret += 2505600; |
| 75 | else ret += 2419200; |
| 76 | } |
| 77 | } |
| 78 | return ret; |
| 79 | } |
| 80 | |
| 81 | |
| 82 | /* |
| 83 | * Initialize the time of day register, based on the time base which is, e.g. |
| 84 | * from a filesystem. |
| 85 | */ |
| 86 | inittodr(base) |
| 87 | time_t base; |
| 88 | { |
| 89 | unsigned long sec; |
| 90 | int leap,day_week,t,yd; |
| 91 | |
| 92 | sec = bcd(rtcin(9)); leap = !(sec % 4); sec += ytos(sec); /* year */ |
| 93 | yd = mtos(bcd(rtcin(8)),leap); sec += yd; /* month */ |
| 94 | t = (bcd(rtcin(7))-1) * 86400; sec += t; yd += t; /* date */ |
| 95 | day_week = rtcin(6); /* day */ |
| 96 | sec += bcd(rtcin(4)) * 3600; /* hour */ |
| 97 | sec += bcd(rtcin(2)) * 60; /* minutes */ |
| 98 | sec += bcd(rtcin(0)); /* seconds */ |
| 99 | |
| 100 | /* XXX off by one? Need to calculate DST on SUNDAY */ |
| 101 | /* Perhaps we should have the RTC hold GMT time to save */ |
| 102 | /* us the bother of converting. */ |
| 103 | yd = yd / 86400; |
| 104 | if ((yd >= DAYST) && ( yd <= DAYEN)) { |
| 105 | sec -= 3600; |
| 106 | } |
| 107 | sec += tz.tz_minuteswest * 60; |
| 108 | |
| 109 | time.tv_sec = sec; |
| 110 | } |
| 111 | |
| 112 | #ifdef garbage |
| 113 | /* |
| 114 | * Initialze the time of day register, based on the time base which is, e.g. |
| 115 | * from a filesystem. |
| 116 | */ |
| 117 | test_inittodr(base) |
| 118 | time_t base; |
| 119 | { |
| 120 | |
| 121 | outb(IO_RTC,9); /* year */ |
| 122 | printf("%d ",bcd(inb(IO_RTC+1))); |
| 123 | outb(IO_RTC,8); /* month */ |
| 124 | printf("%d ",bcd(inb(IO_RTC+1))); |
| 125 | outb(IO_RTC,7); /* day */ |
| 126 | printf("%d ",bcd(inb(IO_RTC+1))); |
| 127 | outb(IO_RTC,4); /* hour */ |
| 128 | printf("%d ",bcd(inb(IO_RTC+1))); |
| 129 | outb(IO_RTC,2); /* minutes */ |
| 130 | printf("%d ",bcd(inb(IO_RTC+1))); |
| 131 | outb(IO_RTC,0); /* seconds */ |
| 132 | printf("%d\n",bcd(inb(IO_RTC+1))); |
| 133 | |
| 134 | time.tv_sec = base; |
| 135 | } |
| 136 | #endif |
| 137 | |
| 138 | /* |
| 139 | * retreve a value from realtime clock |
| 140 | */ |
| 141 | u_char rtcin(n) { |
| 142 | u_char val; |
| 143 | |
| 144 | outb(IO_RTC,n); |
| 145 | do val = inb(IO_RTC+1) ; while (val != inb(IO_RTC+1)); |
| 146 | return (val); |
| 147 | } |
| 148 | |
| 149 | /* |
| 150 | * Restart the clock. |
| 151 | */ |
| 152 | resettodr() |
| 153 | { |
| 154 | } |
| 155 | |
| 156 | enablertclock() { |
| 157 | INTREN(IRQ0); |
| 158 | splnone(); |
| 159 | } |