mc146818.cc revision 5392
1/* 2 * Copyright (c) 2004-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Ali Saidi 29 * Andrew Schultz 30 * Miguel Serrano 31 */ 32 33#include <sys/time.h> 34#include <time.h> 35 36#include <string> 37 38#include "base/time.hh" 39#include "base/trace.hh" 40#include "dev/mc146818.hh" 41#include "dev/rtcreg.h" 42 43using namespace std; 44 45MC146818::MC146818(const string &n, const struct tm time, 46 bool bcd, Tick frequency) 47 : _name(n), event(this, frequency) 48{ 49 memset(clock_data, 0, sizeof(clock_data)); 50 stat_regA = RTCA_32768HZ | RTCA_1024HZ; 51 stat_regB = RTCB_PRDC_IE |RTCB_BIN | RTCB_24HR; 52 53 year = time.tm_year; 54 55 if (bcd) { 56 // The datasheet says that the year field can be either BCD or 57 // years since 1900. Linux seems to be happy with years since 58 // 1900. 59 year = year % 100; 60 int tens = year / 10; 61 int ones = year % 10; 62 year = (tens << 4) + ones; 63 } 64 65 // Unix is 0-11 for month, data seet says start at 1 66 mon = time.tm_mon + 1; 67 mday = time.tm_mday; 68 hour = time.tm_hour; 69 min = time.tm_min; 70 sec = time.tm_sec; 71 72 // Datasheet says 1 is sunday 73 wday = time.tm_wday + 1; 74 75 DPRINTFN("Real-time clock set to %s", asctime(&time)); 76} 77 78void 79MC146818::writeData(const uint8_t addr, const uint8_t data) 80{ 81 if (addr < RTC_STAT_REGA) 82 clock_data[addr] = data; 83 else { 84 switch (addr) { 85 case RTC_STAT_REGA: 86 if (data != (RTCA_32768HZ | RTCA_1024HZ)) 87 panic("Unimplemented RTC register A value write!\n"); 88 stat_regA = data; 89 break; 90 case RTC_STAT_REGB: 91 if ((data & ~(RTCB_PRDC_IE | RTCB_SQWE)) != (RTCB_BIN | RTCB_24HR)) 92 panic("Write to RTC reg B bits that are not implemented!\n"); 93 94 if (data & RTCB_PRDC_IE) { 95 if (!event.scheduled()) 96 event.scheduleIntr(); 97 } else { 98 if (event.scheduled()) 99 event.deschedule(); 100 } 101 stat_regB = data; 102 break; 103 case RTC_STAT_REGC: 104 case RTC_STAT_REGD: 105 panic("RTC status registers C and D are not implemented.\n"); 106 break; 107 } 108 } 109} 110 111uint8_t 112MC146818::readData(uint8_t addr) 113{ 114 if (addr < RTC_STAT_REGA) 115 return clock_data[addr]; 116 else { 117 switch (addr) { 118 case RTC_STAT_REGA: 119 // toggle UIP bit for linux 120 stat_regA ^= RTCA_UIP; 121 return stat_regA; 122 break; 123 case RTC_STAT_REGB: 124 return stat_regB; 125 break; 126 case RTC_STAT_REGC: 127 case RTC_STAT_REGD: 128 return 0x00; 129 break; 130 default: 131 panic("Shouldn't be here"); 132 } 133 } 134} 135 136void 137MC146818::serialize(const string &base, ostream &os) 138{ 139 arrayParamOut(os, base + ".clock_data", clock_data, sizeof(clock_data)); 140 paramOut(os, base + ".stat_regA", stat_regA); 141 paramOut(os, base + ".stat_regB", stat_regB); 142} 143 144void 145MC146818::unserialize(const string &base, Checkpoint *cp, 146 const string §ion) 147{ 148 arrayParamIn(cp, section, base + ".clock_data", clock_data, 149 sizeof(clock_data)); 150 paramIn(cp, section, base + ".stat_regA", stat_regA); 151 paramIn(cp, section, base + ".stat_regB", stat_regB); 152 153 // We're not unserializing the event here, but we need to 154 // rescehedule the event since curTick was moved forward by the 155 // checkpoint 156 event.reschedule(curTick + event.interval); 157} 158 159MC146818::RTCEvent::RTCEvent(MC146818 * _parent, Tick i) 160 : Event(&mainEventQueue), parent(_parent), interval(i) 161{ 162 DPRINTF(MC146818, "RTC Event Initilizing\n"); 163 schedule(curTick + interval); 164} 165 166void 167MC146818::RTCEvent::scheduleIntr() 168{ 169 schedule(curTick + interval); 170} 171 172void 173MC146818::RTCEvent::process() 174{ 175 DPRINTF(MC146818, "RTC Timer Interrupt\n"); 176 schedule(curTick + interval); 177 parent->handleEvent(); 178} 179 180const char * 181MC146818::RTCEvent::description() const 182{ 183 return "RTC interrupt"; 184} 185