src/dev/mc146818.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2004-2005 The Regents of The University of Michigan
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met: redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer;
  * redistributions in binary form must reproduce the above copyright
  * notice, this list of conditions and the following disclaimer in the
  * documentation and/or other materials provided with the distribution;
  * neither the name of the copyright holders nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "dev/mc146818.hh"

 #include <sys/time.h>

 #include <ctime>
 #include <string>

 #include "base/bitfield.hh"
 #include "base/time.hh"
 #include "base/trace.hh"
 #include "debug/MC146818.hh"
 #include "dev/rtcreg.h"

 namespace gem5
 {

 static uint8_t
 bcdize(uint8_t val)
 {
     uint8_t result;
     result = val % 10;
     result += (val / 10) << 4;
     return result;
 }

 static uint8_t
 unbcdize(uint8_t val)
 {
     uint8_t result;
     result = val & 0xf;
     result += (val >> 4) * 10;
     return result;
 }

 void
 MC146818::setTime(const struct tm time)
 {
     curTime = time;
     year = time.tm_year;
     // Unix is 0-11 for month, data seet says start at 1
     mon = time.tm_mon + 1;
     mday = time.tm_mday;
     hour = time.tm_hour;
     min = time.tm_min;
     sec = time.tm_sec;

     // Datasheet says 1 is sunday
     wday = time.tm_wday + 1;

     if (!stat_regB.dm) {
         // The datasheet says that the year field can be either BCD or
         // years since 1900.  Linux seems to be happy with years since
         // 1900.
         year = bcdize(year % 100);
         mon = bcdize(mon);
         mday = bcdize(mday);
         hour = bcdize(hour);
         min = bcdize(min);
         sec = bcdize(sec);
     }
 }

 MC146818::MC146818(EventManager *em, const std::string &n,
         const struct tm time, bool bcd, Tick frequency)
     : EventManager(em), _name(n), event(this, frequency), tickEvent(this)
 {
     memset(clock_data, 0, sizeof(clock_data));

     stat_regA = 0;
     stat_regA.dv = RTCA_DV_32768HZ;
     stat_regA.rs = RTCA_RS_1024HZ;

     stat_regB = 0;
     stat_regB.pie = 1;
     stat_regB.format24h = 1;
     stat_regB.dm = bcd ? 0 : 1;

     setTime(time);
     DPRINTFN("Real-time clock set to %s", asctime(&time));
 }

 MC146818::~MC146818()
 {
     deschedule(tickEvent);
     deschedule(event);
 }

 bool
 MC146818::rega_dv_disabled(const RtcRegA &reg)
 {
     return reg.dv == RTCA_DV_DISABLED0 ||
         reg.dv == RTCA_DV_DISABLED1;
 }

 void
 MC146818::startup()
 {
     assert(!event.scheduled());
     assert(!tickEvent.scheduled());

     if (stat_regB.pie)
         schedule(event, curTick() + event.offset);
     if (!rega_dv_disabled(stat_regA))
         schedule(tickEvent, curTick() + tickEvent.offset);
 }

 void
 MC146818::writeData(const uint8_t addr, const uint8_t data)
 {
     bool panic_unsupported(false);

     if (addr < RTC_STAT_REGA) {
         clock_data[addr] = data;
         curTime.tm_sec = unbcdize(sec);
         curTime.tm_min = unbcdize(min);
         curTime.tm_hour = unbcdize(hour);
         curTime.tm_mday = unbcdize(mday);
         curTime.tm_mon = unbcdize(mon) - 1;
         curTime.tm_year = ((unbcdize(year) + 50) % 100) + 1950;
         curTime.tm_wday = unbcdize(wday) - 1;
     } else {
         switch (addr) {
           case RTC_STAT_REGA: {
               RtcRegA old_rega(stat_regA);
               stat_regA = data;
               // The "update in progress" bit is read only.
               stat_regA.uip = old_rega;

               if (!rega_dv_disabled(stat_regA) &&
                   stat_regA.dv != RTCA_DV_32768HZ) {
                   inform("RTC: Unimplemented divider configuration: %i\n",
                         stat_regA.dv);
                   panic_unsupported = true;
               }

               if (stat_regA.rs != RTCA_RS_1024HZ) {
                   inform("RTC: Unimplemented interrupt rate: %i\n",
                         stat_regA.rs);
                   panic_unsupported = true;
               }

               if (rega_dv_disabled(stat_regA)) {
                   // The divider is disabled, make sure that we don't
                   // schedule any ticks.
                   if (tickEvent.scheduled())
                       deschedule(tickEvent);
               } else if (rega_dv_disabled(old_rega))  {
                   // According to the specification, the next tick
                   // happens after 0.5s when the divider chain goes
                   // from reset to active. So, we simply schedule the
                   // tick after 0.5s.
                   assert(!tickEvent.scheduled());
                   schedule(tickEvent, curTick() + sim_clock::as_int::s / 2);
               }
           } break;
           case RTC_STAT_REGB:
             stat_regB = data;
             if (stat_regB.aie || stat_regB.uie) {
                 inform("RTC: Unimplemented interrupt configuration: %s %s\n",
                       stat_regB.aie ? "alarm" : "",
                       stat_regB.uie ? "update" : "");
                 panic_unsupported = true;
             }

             if (stat_regB.dm) {
                 inform("RTC: The binary interface is not fully implemented.\n");
                 panic_unsupported = true;
             }

             if (!stat_regB.format24h) {
                 inform("RTC: The 12h time format not supported.\n");
                 panic_unsupported = true;
             }

             if (stat_regB.dse) {
                 inform("RTC: Automatic daylight saving time not supported.\n");
                 panic_unsupported = true;
             }

             if (stat_regB.pie) {
                 if (!event.scheduled())
                     event.scheduleIntr();
             } else {
                 if (event.scheduled())
                     deschedule(event);
             }
             break;
           case RTC_STAT_REGC:
           case RTC_STAT_REGD:
             panic("RTC status registers C and D are not implemented.\n");
             break;
         }
     }

     if (panic_unsupported)
         panic("Unimplemented RTC configuration!\n");

 }

 uint8_t
 MC146818::readData(uint8_t addr)
 {
     if (addr < RTC_STAT_REGA)
         return clock_data[addr];
     else {
         switch (addr) {
           case RTC_STAT_REGA:
             // toggle UIP bit for linux
             stat_regA.uip = !stat_regA.uip;
             return stat_regA;
             break;
           case RTC_STAT_REGB:
             return stat_regB;
             break;
           case RTC_STAT_REGC:
           case RTC_STAT_REGD:
             return 0x00;
             break;
           default:
             panic("Shouldn't be here");
         }
     }
 }

 void
 MC146818::tickClock()
 {
     assert(!rega_dv_disabled(stat_regA));

     if (stat_regB.set)
         return;
     time_t calTime = mkutctime(&curTime);
     calTime++;
     setTime(*gmtime(&calTime));
 }

 void
 MC146818::serialize(const std::string &base, CheckpointOut &cp) const
 {
     uint8_t regA_serial(stat_regA);
     uint8_t regB_serial(stat_regB);

     arrayParamOut(cp, base + ".clock_data", clock_data, sizeof(clock_data));
     paramOut(cp, base + ".stat_regA", (uint8_t)regA_serial);
     paramOut(cp, base + ".stat_regB", (uint8_t)regB_serial);

     //
     // save the timer tick and rtc clock tick values to correctly reschedule
     // them during unserialize
     //
     Tick rtcTimerInterruptTickOffset = event.when() - curTick();
     SERIALIZE_SCALAR(rtcTimerInterruptTickOffset);
     Tick rtcClockTickOffset = tickEvent.when() - curTick();
     SERIALIZE_SCALAR(rtcClockTickOffset);
 }

 void
 MC146818::unserialize(const std::string &base, CheckpointIn &cp)
 {
     uint8_t tmp8;

     arrayParamIn(cp, base + ".clock_data", clock_data,
                  sizeof(clock_data));

     paramIn(cp, base + ".stat_regA", tmp8);
     stat_regA = tmp8;
     paramIn(cp, base + ".stat_regB", tmp8);
     stat_regB = tmp8;

     //
     // properly schedule the timer and rtc clock events
     //
     Tick rtcTimerInterruptTickOffset;
     UNSERIALIZE_SCALAR(rtcTimerInterruptTickOffset);
     event.offset = rtcTimerInterruptTickOffset;
     Tick rtcClockTickOffset;
     UNSERIALIZE_SCALAR(rtcClockTickOffset);
     tickEvent.offset = rtcClockTickOffset;
 }

 MC146818::RTCEvent::RTCEvent(MC146818 * _parent, Tick i)
     : parent(_parent), interval(i), offset(i)
 {
     DPRINTF(MC146818, "RTC Event Initilizing\n");
 }

 void
 MC146818::RTCEvent::scheduleIntr()
 {
     parent->schedule(this, curTick() + interval);
 }

 void
 MC146818::RTCEvent::process()
 {
     DPRINTF(MC146818, "RTC Timer Interrupt\n");
     parent->schedule(this, curTick() + interval);
     parent->handleEvent();
 }

 const char *
 MC146818::RTCEvent::description() const
 {
     return "RTC interrupt";
 }

 void
 MC146818::RTCTickEvent::process()
 {
     DPRINTF(MC146818, "RTC clock tick\n");
     parent->schedule(this, curTick() + sim_clock::as_int::s);
     parent->tickClock();
 }

 const char *
 MC146818::RTCTickEvent::description() const
 {
     return "RTC clock tick";
 }

 } // namespace gem5
	/*
	* Copyright (c) 2004-2005 The Regents of The University of Michigan
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met: redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer;
	* redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution;
	* neither the name of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "dev/mc146818.hh"

	#include <sys/time.h>

	#include <ctime>
	#include <string>

	#include "base/bitfield.hh"
	#include "base/time.hh"
	#include "base/trace.hh"
	#include "debug/MC146818.hh"
	#include "dev/rtcreg.h"

	namespace gem5
	{

	static uint8_t
	bcdize(uint8_t val)
	{
	uint8_t result;
	result = val % 10;
	result += (val / 10) << 4;
	return result;
	}

	static uint8_t
	unbcdize(uint8_t val)
	{
	uint8_t result;
	result = val & 0xf;
	result += (val >> 4) * 10;
	return result;
	}

	void
	MC146818::setTime(const struct tm time)
	{
	curTime = time;
	year = time.tm_year;
	// Unix is 0-11 for month, data seet says start at 1
	mon = time.tm_mon + 1;
	mday = time.tm_mday;
	hour = time.tm_hour;
	min = time.tm_min;
	sec = time.tm_sec;

	// Datasheet says 1 is sunday
	wday = time.tm_wday + 1;

	if (!stat_regB.dm) {
	// The datasheet says that the year field can be either BCD or
	// years since 1900. Linux seems to be happy with years since
	// 1900.
	year = bcdize(year % 100);
	mon = bcdize(mon);
	mday = bcdize(mday);
	hour = bcdize(hour);
	min = bcdize(min);
	sec = bcdize(sec);
	}
	}

	MC146818::MC146818(EventManager *em, const std::string &n,
	const struct tm time, bool bcd, Tick frequency)
	: EventManager(em), _name(n), event(this, frequency), tickEvent(this)
	{
	memset(clock_data, 0, sizeof(clock_data));

	stat_regA = 0;
	stat_regA.dv = RTCA_DV_32768HZ;
	stat_regA.rs = RTCA_RS_1024HZ;

	stat_regB = 0;
	stat_regB.pie = 1;
	stat_regB.format24h = 1;
	stat_regB.dm = bcd ? 0 : 1;

	setTime(time);
	DPRINTFN("Real-time clock set to %s", asctime(&time));
	}

	MC146818::~MC146818()
	{
	deschedule(tickEvent);
	deschedule(event);
	}

	bool
	MC146818::rega_dv_disabled(const RtcRegA &reg)
	{
	return reg.dv == RTCA_DV_DISABLED0 \|\|
	reg.dv == RTCA_DV_DISABLED1;
	}

	void
	MC146818::startup()
	{
	assert(!event.scheduled());
	assert(!tickEvent.scheduled());

	if (stat_regB.pie)
	schedule(event, curTick() + event.offset);
	if (!rega_dv_disabled(stat_regA))
	schedule(tickEvent, curTick() + tickEvent.offset);
	}

	void
	MC146818::writeData(const uint8_t addr, const uint8_t data)
	{
	bool panic_unsupported(false);

	if (addr < RTC_STAT_REGA) {
	clock_data[addr] = data;
	curTime.tm_sec = unbcdize(sec);
	curTime.tm_min = unbcdize(min);
	curTime.tm_hour = unbcdize(hour);
	curTime.tm_mday = unbcdize(mday);
	curTime.tm_mon = unbcdize(mon) - 1;
	curTime.tm_year = ((unbcdize(year) + 50) % 100) + 1950;
	curTime.tm_wday = unbcdize(wday) - 1;
	} else {
	switch (addr) {
	case RTC_STAT_REGA: {
	RtcRegA old_rega(stat_regA);
	stat_regA = data;
	// The "update in progress" bit is read only.
	stat_regA.uip = old_rega;

	if (!rega_dv_disabled(stat_regA) &&
	stat_regA.dv != RTCA_DV_32768HZ) {
	inform("RTC: Unimplemented divider configuration: %i\n",
	stat_regA.dv);
	panic_unsupported = true;
	}

	if (stat_regA.rs != RTCA_RS_1024HZ) {
	inform("RTC: Unimplemented interrupt rate: %i\n",
	stat_regA.rs);
	panic_unsupported = true;
	}

	if (rega_dv_disabled(stat_regA)) {
	// The divider is disabled, make sure that we don't
	// schedule any ticks.
	if (tickEvent.scheduled())
	deschedule(tickEvent);
	} else if (rega_dv_disabled(old_rega)) {
	// According to the specification, the next tick
	// happens after 0.5s when the divider chain goes
	// from reset to active. So, we simply schedule the
	// tick after 0.5s.
	assert(!tickEvent.scheduled());
	schedule(tickEvent, curTick() + sim_clock::as_int::s / 2);
	}
	} break;
	case RTC_STAT_REGB:
	stat_regB = data;
	if (stat_regB.aie \|\| stat_regB.uie) {
	inform("RTC: Unimplemented interrupt configuration: %s %s\n",
	stat_regB.aie ? "alarm" : "",
	stat_regB.uie ? "update" : "");
	panic_unsupported = true;
	}

	if (stat_regB.dm) {
	inform("RTC: The binary interface is not fully implemented.\n");
	panic_unsupported = true;
	}

	if (!stat_regB.format24h) {
	inform("RTC: The 12h time format not supported.\n");
	panic_unsupported = true;
	}

	if (stat_regB.dse) {
	inform("RTC: Automatic daylight saving time not supported.\n");
	panic_unsupported = true;
	}

	if (stat_regB.pie) {
	if (!event.scheduled())
	event.scheduleIntr();
	} else {
	if (event.scheduled())
	deschedule(event);
	}
	break;
	case RTC_STAT_REGC:
	case RTC_STAT_REGD:
	panic("RTC status registers C and D are not implemented.\n");
	break;
	}
	}

	if (panic_unsupported)
	panic("Unimplemented RTC configuration!\n");

	}

	uint8_t
	MC146818::readData(uint8_t addr)
	{
	if (addr < RTC_STAT_REGA)
	return clock_data[addr];
	else {
	switch (addr) {
	case RTC_STAT_REGA:
	// toggle UIP bit for linux
	stat_regA.uip = !stat_regA.uip;
	return stat_regA;
	break;
	case RTC_STAT_REGB:
	return stat_regB;
	break;
	case RTC_STAT_REGC:
	case RTC_STAT_REGD:
	return 0x00;
	break;
	default:
	panic("Shouldn't be here");
	}
	}
	}

	void
	MC146818::tickClock()
	{
	assert(!rega_dv_disabled(stat_regA));

	if (stat_regB.set)
	return;
	time_t calTime = mkutctime(&curTime);
	calTime++;
	setTime(*gmtime(&calTime));
	}

	void
	MC146818::serialize(const std::string &base, CheckpointOut &cp) const
	{
	uint8_t regA_serial(stat_regA);
	uint8_t regB_serial(stat_regB);

	arrayParamOut(cp, base + ".clock_data", clock_data, sizeof(clock_data));
	paramOut(cp, base + ".stat_regA", (uint8_t)regA_serial);
	paramOut(cp, base + ".stat_regB", (uint8_t)regB_serial);

	//
	// save the timer tick and rtc clock tick values to correctly reschedule
	// them during unserialize
	//
	Tick rtcTimerInterruptTickOffset = event.when() - curTick();
	SERIALIZE_SCALAR(rtcTimerInterruptTickOffset);
	Tick rtcClockTickOffset = tickEvent.when() - curTick();
	SERIALIZE_SCALAR(rtcClockTickOffset);
	}

	void
	MC146818::unserialize(const std::string &base, CheckpointIn &cp)
	{
	uint8_t tmp8;

	arrayParamIn(cp, base + ".clock_data", clock_data,
	sizeof(clock_data));

	paramIn(cp, base + ".stat_regA", tmp8);
	stat_regA = tmp8;
	paramIn(cp, base + ".stat_regB", tmp8);
	stat_regB = tmp8;

	//
	// properly schedule the timer and rtc clock events
	//
	Tick rtcTimerInterruptTickOffset;
	UNSERIALIZE_SCALAR(rtcTimerInterruptTickOffset);
	event.offset = rtcTimerInterruptTickOffset;
	Tick rtcClockTickOffset;
	UNSERIALIZE_SCALAR(rtcClockTickOffset);
	tickEvent.offset = rtcClockTickOffset;
	}

	MC146818::RTCEvent::RTCEvent(MC146818 * _parent, Tick i)
	: parent(_parent), interval(i), offset(i)
	{
	DPRINTF(MC146818, "RTC Event Initilizing\n");
	}

	void
	MC146818::RTCEvent::scheduleIntr()
	{
	parent->schedule(this, curTick() + interval);
	}

	void
	MC146818::RTCEvent::process()
	{
	DPRINTF(MC146818, "RTC Timer Interrupt\n");
	parent->schedule(this, curTick() + interval);
	parent->handleEvent();
	}

	const char *
	MC146818::RTCEvent::description() const
	{
	return "RTC interrupt";
	}

	void
	MC146818::RTCTickEvent::process()
	{
	DPRINTF(MC146818, "RTC clock tick\n");
	parent->schedule(this, curTick() + sim_clock::as_int::s);
	parent->tickClock();
	}

	const char *
	MC146818::RTCTickEvent::description() const
	{
	return "RTC clock tick";
	}

	} // namespace gem5