intel_8254_timer.cc revision 5443:394d180e8c04
1/* 2 * Copyright (c) 2004, 2005 3 * The Regents of The University of Michigan 4 * All Rights Reserved 5 * 6 * This code is part of the M5 simulator. 7 * 8 * Permission is granted to use, copy, create derivative works and 9 * redistribute this software and such derivative works for any 10 * purpose, so long as the copyright notice above, this grant of 11 * permission, and the disclaimer below appear in all copies made; and 12 * so long as the name of The University of Michigan is not used in 13 * any advertising or publicity pertaining to the use or distribution 14 * of this software without specific, written prior authorization. 15 * 16 * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE 17 * UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND 18 * WITHOUT WARRANTY BY THE UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER 19 * EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED 20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21 * PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE 22 * LIABLE FOR ANY DAMAGES, INCLUDING DIRECT, SPECIAL, INDIRECT, 23 * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM 24 * ARISING OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN 25 * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF SUCH 26 * DAMAGES. 27 * 28 * Authors: Ali G. Saidi 29 * Andrew L. Schultz 30 * Miguel J. Serrano 31 */ 32 33#include "base/misc.hh" 34#include "dev/intel_8254_timer.hh" 35 36using namespace std; 37 38Intel8254Timer::Intel8254Timer(const string &name) 39 : _name(name), counter0(name + ".counter0"), counter1(name + ".counter1"), 40 counter2(name + ".counter2") 41{ 42 counter[0] = &counter0; 43 counter[1] = &counter0; 44 counter[2] = &counter0; 45} 46 47void 48Intel8254Timer::writeControl(const CtrlReg data) 49{ 50 int sel = data.sel; 51 52 if (sel == ReadBackCommand) 53 panic("PITimer Read-Back Command is not implemented.\n"); 54 55 if (data.rw == LatchCommand) 56 counter[sel]->latchCount(); 57 else { 58 counter[sel]->setRW(data.rw); 59 counter[sel]->setMode(data.mode); 60 counter[sel]->setBCD(data.bcd); 61 } 62} 63 64void 65Intel8254Timer::serialize(const string &base, ostream &os) 66{ 67 // serialize the counters 68 counter0.serialize(base + ".counter0", os); 69 counter1.serialize(base + ".counter1", os); 70 counter2.serialize(base + ".counter2", os); 71} 72 73void 74Intel8254Timer::unserialize(const string &base, Checkpoint *cp, 75 const string §ion) 76{ 77 // unserialze the counters 78 counter0.unserialize(base + ".counter0", cp, section); 79 counter1.unserialize(base + ".counter1", cp, section); 80 counter2.unserialize(base + ".counter2", cp, section); 81} 82 83Intel8254Timer::Counter::Counter(const string &name) 84 : _name(name), event(this), count(0), latched_count(0), period(0), 85 mode(0), output_high(false), latch_on(false), read_byte(LSB), 86 write_byte(LSB) 87{ 88 89} 90 91void 92Intel8254Timer::Counter::latchCount() 93{ 94 // behave like a real latch 95 if(!latch_on) { 96 latch_on = true; 97 read_byte = LSB; 98 latched_count = count; 99 } 100} 101 102uint8_t 103Intel8254Timer::Counter::read() 104{ 105 if (latch_on) { 106 switch (read_byte) { 107 case LSB: 108 read_byte = MSB; 109 return (uint8_t)latched_count; 110 break; 111 case MSB: 112 read_byte = LSB; 113 latch_on = false; 114 return latched_count >> 8; 115 break; 116 default: 117 panic("Shouldn't be here"); 118 } 119 } else { 120 switch (read_byte) { 121 case LSB: 122 read_byte = MSB; 123 return (uint8_t)count; 124 break; 125 case MSB: 126 read_byte = LSB; 127 return count >> 8; 128 break; 129 default: 130 panic("Shouldn't be here"); 131 } 132 } 133} 134 135void 136Intel8254Timer::Counter::write(const uint8_t data) 137{ 138 switch (write_byte) { 139 case LSB: 140 count = (count & 0xFF00) | data; 141 142 if (event.scheduled()) 143 event.deschedule(); 144 output_high = false; 145 write_byte = MSB; 146 break; 147 148 case MSB: 149 count = (count & 0x00FF) | (data << 8); 150 period = count; 151 152 if (period > 0) { 153 DPRINTF(Intel8254Timer, "Timer set to curTick + %d\n", 154 count * event.interval); 155 event.schedule(curTick + count * event.interval); 156 } 157 write_byte = LSB; 158 break; 159 } 160} 161 162void 163Intel8254Timer::Counter::setRW(int rw_val) 164{ 165 if (rw_val != TwoPhase) 166 panic("Only LSB/MSB read/write is implemented.\n"); 167} 168 169void 170Intel8254Timer::Counter::setMode(int mode_val) 171{ 172 if(mode_val != InitTc && mode_val != RateGen && 173 mode_val != SquareWave) 174 panic("PIT mode %#x is not implemented: \n", mode_val); 175 176 mode = mode_val; 177} 178 179void 180Intel8254Timer::Counter::setBCD(int bcd_val) 181{ 182 if (bcd_val) 183 panic("PITimer does not implement BCD counts.\n"); 184} 185 186bool 187Intel8254Timer::Counter::outputHigh() 188{ 189 return output_high; 190} 191 192void 193Intel8254Timer::Counter::serialize(const string &base, ostream &os) 194{ 195 paramOut(os, base + ".count", count); 196 paramOut(os, base + ".latched_count", latched_count); 197 paramOut(os, base + ".period", period); 198 paramOut(os, base + ".mode", mode); 199 paramOut(os, base + ".output_high", output_high); 200 paramOut(os, base + ".latch_on", latch_on); 201 paramOut(os, base + ".read_byte", read_byte); 202 paramOut(os, base + ".write_byte", write_byte); 203 204 Tick event_tick = 0; 205 if (event.scheduled()) 206 event_tick = event.when(); 207 paramOut(os, base + ".event_tick", event_tick); 208} 209 210void 211Intel8254Timer::Counter::unserialize(const string &base, Checkpoint *cp, 212 const string §ion) 213{ 214 paramIn(cp, section, base + ".count", count); 215 paramIn(cp, section, base + ".latched_count", latched_count); 216 paramIn(cp, section, base + ".period", period); 217 paramIn(cp, section, base + ".mode", mode); 218 paramIn(cp, section, base + ".output_high", output_high); 219 paramIn(cp, section, base + ".latch_on", latch_on); 220 paramIn(cp, section, base + ".read_byte", read_byte); 221 paramIn(cp, section, base + ".write_byte", write_byte); 222 223 Tick event_tick; 224 paramIn(cp, section, base + ".event_tick", event_tick); 225 if (event_tick) 226 event.schedule(event_tick); 227} 228 229Intel8254Timer::Counter::CounterEvent::CounterEvent(Counter* c_ptr) 230 : Event(&mainEventQueue) 231{ 232 interval = (Tick)(Clock::Float::s / 1193180.0); 233 counter = c_ptr; 234} 235 236void 237Intel8254Timer::Counter::CounterEvent::process() 238{ 239 DPRINTF(Intel8254Timer, "Timer Interrupt\n"); 240 switch (counter->mode) { 241 case InitTc: 242 counter->output_high = true; 243 case RateGen: 244 case SquareWave: 245 break; 246 default: 247 panic("Unimplemented PITimer mode.\n"); 248 } 249} 250 251const char * 252Intel8254Timer::Counter::CounterEvent::description() const 253{ 254 return "tsunami 8254 Interval timer"; 255} 256