X86: Make the real time clock actually keep track of time.

This commit is contained in:
Gabe Black 2009-08-20 00:42:43 -07:00
parent e8c0ca5cd1
commit da3c3bfa98
2 changed files with 103 additions and 19 deletions

View file

@ -43,28 +43,20 @@
using namespace std;
MC146818::MC146818(EventManager *em, const string &n, const struct tm time,
bool bcd, Tick frequency)
: EventManager(em), _name(n), event(this, frequency)
static uint8_t
bcdize(uint8_t val)
{
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;
year = time.tm_year;
if (bcd) {
// 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 = year % 100;
int tens = year / 10;
int ones = year % 10;
year = (tens << 4) + ones;
uint8_t result;
result = val % 10;
result += (val / 10) << 4;
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;
@ -75,6 +67,30 @@ MC146818::MC146818(EventManager *em, const string &n, const struct tm time,
// 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));
}
@ -141,6 +157,34 @@ MC146818::readData(uint8_t addr)
}
}
static time_t
mkutctime(struct tm *time)
{
time_t ret;
char *tz;
tz = getenv("TZ");
setenv("TZ", "", 1);
tzset();
ret = mktime(time);
if (tz)
setenv("TZ", tz, 1);
else
unsetenv("TZ");
tzset();
return ret;
}
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)
{
@ -190,3 +234,17 @@ MC146818::RTCEvent::description() const
{
return "RTC interrupt";
}
void
MC146818::RTCTickEvent::process()
{
DPRINTF(MC146818, "RTC clock tick\n");
parent->schedule(this, curTick + Clock::Int::s);
parent->tickClock();
}
const char *
MC146818::RTCTickEvent::description() const
{
return "RTC clock tick";
}

View file

@ -64,6 +64,23 @@ class MC146818 : public EventManager
virtual const char *description() const;
};
/** Event for RTC periodic interrupt */
struct RTCTickEvent : public Event
{
MC146818 * parent;
RTCTickEvent(MC146818 * _parent) : parent(_parent)
{
parent->schedule(this, curTick + Clock::Int::s);
}
/** Event process to occur at interrupt*/
void process();
/** Event description */
const char *description() const;
};
private:
std::string _name;
const std::string &name() const { return _name; }
@ -71,6 +88,9 @@ class MC146818 : public EventManager
/** RTC periodic interrupt event */
RTCEvent event;
/** RTC tick event */
RTCTickEvent tickEvent;
/** Data for real-time clock function */
union {
uint8_t clock_data[10];
@ -89,6 +109,10 @@ class MC146818 : public EventManager
};
};
struct tm curTime;
void setTime(const struct tm time);
/** RTC status register A */
uint8_t stat_regA;
@ -106,6 +130,8 @@ class MC146818 : public EventManager
/** RTC read data */
uint8_t readData(const uint8_t addr);
void tickClock();
/**
* Serialize this object to the given output stream.
* @param base The base name of the counter object.