intel_8254_timer.cc revision 11793:ef606668d247
112855Sgabeblack@google.com/* 212855Sgabeblack@google.com * Copyright (c) 2004, 2005 312855Sgabeblack@google.com * The Regents of The University of Michigan 412855Sgabeblack@google.com * All Rights Reserved 512855Sgabeblack@google.com * 612855Sgabeblack@google.com * This code is part of the M5 simulator. 712855Sgabeblack@google.com * 812855Sgabeblack@google.com * Permission is granted to use, copy, create derivative works and 912855Sgabeblack@google.com * redistribute this software and such derivative works for any 1012855Sgabeblack@google.com * purpose, so long as the copyright notice above, this grant of 1112855Sgabeblack@google.com * permission, and the disclaimer below appear in all copies made; and 1212855Sgabeblack@google.com * so long as the name of The University of Michigan is not used in 1312855Sgabeblack@google.com * any advertising or publicity pertaining to the use or distribution 1412855Sgabeblack@google.com * of this software without specific, written prior authorization. 1512855Sgabeblack@google.com * 1612855Sgabeblack@google.com * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE 1712855Sgabeblack@google.com * UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND 1812855Sgabeblack@google.com * WITHOUT WARRANTY BY THE UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER 1912855Sgabeblack@google.com * EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED 2012855Sgabeblack@google.com * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 2112855Sgabeblack@google.com * PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE 2212855Sgabeblack@google.com * LIABLE FOR ANY DAMAGES, INCLUDING DIRECT, SPECIAL, INDIRECT, 2312855Sgabeblack@google.com * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM 2412855Sgabeblack@google.com * ARISING OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN 2512855Sgabeblack@google.com * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF SUCH 2612855Sgabeblack@google.com * DAMAGES. 2712855Sgabeblack@google.com * 2812855Sgabeblack@google.com * Authors: Ali G. Saidi 2912855Sgabeblack@google.com * Andrew L. Schultz 3012855Sgabeblack@google.com * Miguel J. Serrano 3112855Sgabeblack@google.com */ 3212855Sgabeblack@google.com 3312855Sgabeblack@google.com#include "dev/intel_8254_timer.hh" 3412855Sgabeblack@google.com 3512855Sgabeblack@google.com#include "base/misc.hh" 3612855Sgabeblack@google.com#include "debug/Intel8254Timer.hh" 3712855Sgabeblack@google.com 3812855Sgabeblack@google.comusing namespace std; 3912855Sgabeblack@google.com 4012855Sgabeblack@google.comIntel8254Timer::Intel8254Timer(EventManager *em, const string &name, 4112855Sgabeblack@google.com Counter *counter0, Counter *counter1, Counter *counter2) : 4212855Sgabeblack@google.com EventManager(em), _name(name) 4312855Sgabeblack@google.com{ 4412855Sgabeblack@google.com counter[0] = counter0; 4512855Sgabeblack@google.com counter[1] = counter1; 4612855Sgabeblack@google.com counter[2] = counter2; 4712855Sgabeblack@google.com} 4812855Sgabeblack@google.com 4912855Sgabeblack@google.comIntel8254Timer::Intel8254Timer(EventManager *em, const string &name) : 5012855Sgabeblack@google.com EventManager(em), _name(name) 5112855Sgabeblack@google.com{ 5212855Sgabeblack@google.com counter[0] = new Counter(this, name + ".counter0", 0); 5312855Sgabeblack@google.com counter[1] = new Counter(this, name + ".counter1", 1); 5412855Sgabeblack@google.com counter[2] = new Counter(this, name + ".counter2", 2); 5512855Sgabeblack@google.com} 5612855Sgabeblack@google.com 5712855Sgabeblack@google.comvoid 5812855Sgabeblack@google.comIntel8254Timer::writeControl(const CtrlReg data) 5912855Sgabeblack@google.com{ 6012855Sgabeblack@google.com int sel = data.sel; 6112855Sgabeblack@google.com 6212855Sgabeblack@google.com if (sel == ReadBackCommand) 6312855Sgabeblack@google.com panic("PITimer Read-Back Command is not implemented.\n"); 6412855Sgabeblack@google.com 6512855Sgabeblack@google.com if (data.rw == LatchCommand) 6612855Sgabeblack@google.com counter[sel]->latchCount(); 6712855Sgabeblack@google.com else { 6812855Sgabeblack@google.com counter[sel]->setRW(data.rw); 6912855Sgabeblack@google.com counter[sel]->setMode(data.mode); 7012855Sgabeblack@google.com counter[sel]->setBCD(data.bcd); 7112855Sgabeblack@google.com } 7212855Sgabeblack@google.com} 7312855Sgabeblack@google.com 7412855Sgabeblack@google.comvoid 7512855Sgabeblack@google.comIntel8254Timer::serialize(const string &base, CheckpointOut &cp) const 7612855Sgabeblack@google.com{ 7712855Sgabeblack@google.com // serialize the counters 7812855Sgabeblack@google.com counter[0]->serialize(base + ".counter0", cp); 7912855Sgabeblack@google.com counter[1]->serialize(base + ".counter1", cp); 8012855Sgabeblack@google.com counter[2]->serialize(base + ".counter2", cp); 8112855Sgabeblack@google.com} 8212855Sgabeblack@google.com 8312855Sgabeblack@google.comvoid 8412855Sgabeblack@google.comIntel8254Timer::unserialize(const string &base, CheckpointIn &cp) 8512855Sgabeblack@google.com{ 8612855Sgabeblack@google.com // unserialze the counters 8712855Sgabeblack@google.com counter[0]->unserialize(base + ".counter0", cp); 8812855Sgabeblack@google.com counter[1]->unserialize(base + ".counter1", cp); 8912855Sgabeblack@google.com counter[2]->unserialize(base + ".counter2", cp); 9012855Sgabeblack@google.com} 9112855Sgabeblack@google.com 9212855Sgabeblack@google.comvoid 9312855Sgabeblack@google.comIntel8254Timer::startup() 9412855Sgabeblack@google.com{ 9512855Sgabeblack@google.com counter[0]->startup(); 9612855Sgabeblack@google.com counter[1]->startup(); 9712855Sgabeblack@google.com counter[2]->startup(); 9812855Sgabeblack@google.com} 9912855Sgabeblack@google.com 10012855Sgabeblack@google.comIntel8254Timer::Counter::Counter(Intel8254Timer *p, 10112855Sgabeblack@google.com const string &name, unsigned int _num) 10212855Sgabeblack@google.com : _name(name), num(_num), event(this), running(false), 10312855Sgabeblack@google.com initial_count(0), latched_count(0), period(0), mode(0), 10412855Sgabeblack@google.com output_high(false), latch_on(false), read_byte(LSB), 10512855Sgabeblack@google.com write_byte(LSB), parent(p) 10612855Sgabeblack@google.com{ 10712855Sgabeblack@google.com offset = period * event.getInterval(); 10812855Sgabeblack@google.com} 10912855Sgabeblack@google.com 11012855Sgabeblack@google.comvoid 11112855Sgabeblack@google.comIntel8254Timer::Counter::latchCount() 11212855Sgabeblack@google.com{ 11312855Sgabeblack@google.com // behave like a real latch 114 if (!latch_on) { 115 latch_on = true; 116 read_byte = LSB; 117 latched_count = currentCount(); 118 } 119} 120 121int 122Intel8254Timer::Counter::currentCount() 123{ 124 int clocks = event.clocksLeft(); 125 if (clocks == -1) { 126 warn_once("Reading current count from inactive timer.\n"); 127 return 0; 128 } 129 if (mode == RateGen || mode == SquareWave) 130 return clocks + 1; 131 else 132 return clocks; 133} 134 135uint8_t 136Intel8254Timer::Counter::read() 137{ 138 if (latch_on) { 139 switch (read_byte) { 140 case LSB: 141 read_byte = MSB; 142 return (uint8_t)latched_count; 143 break; 144 case MSB: 145 read_byte = LSB; 146 latch_on = false; 147 return latched_count >> 8; 148 break; 149 default: 150 panic("Shouldn't be here"); 151 } 152 } else { 153 uint16_t count = currentCount(); 154 switch (read_byte) { 155 case LSB: 156 read_byte = MSB; 157 return (uint8_t)count; 158 break; 159 case MSB: 160 read_byte = LSB; 161 return count >> 8; 162 break; 163 default: 164 panic("Shouldn't be here"); 165 } 166 } 167} 168 169void 170Intel8254Timer::Counter::write(const uint8_t data) 171{ 172 switch (write_byte) { 173 case LSB: 174 initial_count = (initial_count & 0xFF00) | data; 175 176 if (event.scheduled()) 177 parent->deschedule(event); 178 output_high = false; 179 write_byte = MSB; 180 break; 181 182 case MSB: 183 initial_count = (initial_count & 0x00FF) | (data << 8); 184 // In the RateGen or SquareWave modes, the timer wraps around and 185 // triggers on a value of 1, not 0. 186 if (mode == RateGen || mode == SquareWave) 187 period = initial_count - 1; 188 else 189 period = initial_count; 190 191 offset = period * event.getInterval(); 192 193 if (running && (period > 0)) 194 event.setTo(period); 195 196 write_byte = LSB; 197 break; 198 } 199} 200 201void 202Intel8254Timer::Counter::setRW(int rw_val) 203{ 204 if (rw_val != TwoPhase) 205 panic("Only LSB/MSB read/write is implemented.\n"); 206} 207 208void 209Intel8254Timer::Counter::setMode(int mode_val) 210{ 211 if (mode_val != InitTc && mode_val != RateGen && 212 mode_val != SquareWave) 213 panic("PIT mode %#x is not implemented: \n", mode_val); 214 215 mode = mode_val; 216} 217 218void 219Intel8254Timer::Counter::setBCD(int bcd_val) 220{ 221 if (bcd_val) 222 panic("PITimer does not implement BCD counts.\n"); 223} 224 225bool 226Intel8254Timer::Counter::outputHigh() 227{ 228 return output_high; 229} 230 231void 232Intel8254Timer::Counter::serialize(const string &base, CheckpointOut &cp) const 233{ 234 paramOut(cp, base + ".initial_count", initial_count); 235 paramOut(cp, base + ".latched_count", latched_count); 236 paramOut(cp, base + ".period", period); 237 paramOut(cp, base + ".mode", mode); 238 paramOut(cp, base + ".output_high", output_high); 239 paramOut(cp, base + ".latch_on", latch_on); 240 paramOut(cp, base + ".read_byte", read_byte); 241 paramOut(cp, base + ".write_byte", write_byte); 242 243 Tick event_tick_offset = 0; 244 if (event.scheduled()) 245 event_tick_offset = event.when() - curTick(); 246 paramOut(cp, base + ".event_tick_offset", event_tick_offset); 247} 248 249void 250Intel8254Timer::Counter::unserialize(const string &base, CheckpointIn &cp) 251{ 252 paramIn(cp, base + ".initial_count", initial_count); 253 paramIn(cp, base + ".latched_count", latched_count); 254 paramIn(cp, base + ".period", period); 255 paramIn(cp, base + ".mode", mode); 256 paramIn(cp, base + ".output_high", output_high); 257 paramIn(cp, base + ".latch_on", latch_on); 258 paramIn(cp, base + ".read_byte", read_byte); 259 paramIn(cp, base + ".write_byte", write_byte); 260 261 Tick event_tick_offset = 0; 262 assert(!event.scheduled()); 263 paramIn(cp, base + ".event_tick_offset", event_tick_offset); 264 offset = event_tick_offset; 265} 266 267void 268Intel8254Timer::Counter::startup() 269{ 270 running = true; 271 if ((period > 0) && (offset > 0)) 272 { 273 parent->schedule(event, curTick() + offset); 274 } 275} 276 277Intel8254Timer::Counter::CounterEvent::CounterEvent(Counter* c_ptr) 278{ 279 interval = (Tick)(SimClock::Float::s / 1193180.0); 280 counter = c_ptr; 281} 282 283void 284Intel8254Timer::Counter::CounterEvent::process() 285{ 286 switch (counter->mode) { 287 case InitTc: 288 counter->output_high = true; 289 break; 290 case RateGen: 291 case SquareWave: 292 setTo(counter->period); 293 break; 294 default: 295 panic("Unimplemented PITimer mode.\n"); 296 } 297 counter->parent->counterInterrupt(counter->num); 298} 299 300void 301Intel8254Timer::Counter::CounterEvent::setTo(int clocks) 302{ 303 if (clocks == 0) 304 panic("Timer can't be set to go off instantly.\n"); 305 DPRINTF(Intel8254Timer, "Timer set to curTick() + %d\n", 306 clocks * interval); 307 counter->parent->schedule(this, curTick() + clocks * interval); 308} 309 310int 311Intel8254Timer::Counter::CounterEvent::clocksLeft() 312{ 313 if (!scheduled()) 314 return -1; 315 return (when() - curTick() + interval - 1) / interval; 316} 317 318const char * 319Intel8254Timer::Counter::CounterEvent::description() const 320{ 321 return "Intel 8254 Interval timer"; 322} 323 324Tick 325Intel8254Timer::Counter::CounterEvent::getInterval() 326{ 327 return interval; 328} 329 330