gem5/src/dev/mc146818.cc
Ali Saidi 3876105bdb ARM: Add RTC device for ARM platforms.
This change implements a PL031 real time clock.

--HG--
rename : src/dev/arm/timer_sp804.cc => src/dev/arm/rtc_pl031.cc
rename : src/dev/arm/timer_sp804.hh => src/dev/arm/rtc_pl031.hh
2012-03-01 17:26:31 -06:00

265 lines
7.5 KiB
C++

/*
* 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.
*
* Authors: Ali Saidi
* Andrew Schultz
* Miguel Serrano
*/
#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/mc146818.hh"
#include "dev/rtcreg.h"
using namespace std;
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 & RTCB_BIN)) {
// 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 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 = RTCA_32768HZ | RTCA_1024HZ;
stat_regB = RTCB_PRDC_IE | RTCB_24HR;
if (!bcd)
stat_regB |= RTCB_BIN;
setTime(time);
DPRINTFN("Real-time clock set to %s", asctime(&time));
}
MC146818::~MC146818()
{
deschedule(tickEvent);
deschedule(event);
}
void
MC146818::writeData(const uint8_t addr, const uint8_t data)
{
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:
// The "update in progress" bit is read only.
if ((data & ~RTCA_UIP) != (RTCA_32768HZ | RTCA_1024HZ))
panic("Unimplemented RTC register A value write!\n");
replaceBits(stat_regA, data, 6, 0);
break;
case RTC_STAT_REGB:
if ((data & ~(RTCB_PRDC_IE | RTCB_SQWE)) != RTCB_24HR)
panic("Write to RTC reg B bits that are not implemented!\n");
if (data & RTCB_PRDC_IE) {
if (!event.scheduled())
event.scheduleIntr();
} else {
if (event.scheduled())
deschedule(event);
}
stat_regB = data;
break;
case RTC_STAT_REGC:
case RTC_STAT_REGD:
panic("RTC status registers C and D are not implemented.\n");
break;
}
}
}
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 ^= RTCA_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()
{
if (stat_regB & RTCB_NO_UPDT)
return;
time_t calTime = mkutctime(&curTime);
calTime++;
setTime(*gmtime(&calTime));
}
void
MC146818::serialize(const string &base, ostream &os)
{
arrayParamOut(os, base + ".clock_data", clock_data, sizeof(clock_data));
paramOut(os, base + ".stat_regA", stat_regA);
paramOut(os, base + ".stat_regB", stat_regB);
//
// 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 string &base, Checkpoint *cp,
const string &section)
{
arrayParamIn(cp, section, base + ".clock_data", clock_data,
sizeof(clock_data));
paramIn(cp, section, base + ".stat_regA", stat_regA);
paramIn(cp, section, base + ".stat_regB", stat_regB);
//
// properly schedule the timer and rtc clock events
//
Tick rtcTimerInterruptTickOffset;
UNSERIALIZE_SCALAR(rtcTimerInterruptTickOffset);
reschedule(event, curTick() + rtcTimerInterruptTickOffset);
Tick rtcClockTickOffset;
UNSERIALIZE_SCALAR(rtcClockTickOffset);
reschedule(tickEvent, curTick() + rtcClockTickOffset);
}
MC146818::RTCEvent::RTCEvent(MC146818 * _parent, Tick i)
: parent(_parent), interval(i)
{
DPRINTF(MC146818, "RTC Event Initilizing\n");
parent->schedule(this, curTick() + interval);
}
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() + SimClock::Int::s);
parent->tickClock();
}
const char *
MC146818::RTCTickEvent::description() const
{
return "RTC clock tick";
}