luxos/SysCore/drivers/clock/pit.c
2021-09-14 18:46:50 +03:00

120 lines
4.0 KiB
C

#include <system.h>
#include <time.h>
#include "clock.h"
volatile unsigned int ClockTicks = 0;
volatile unsigned int ClockFrequency = 0;
unsigned char PitInitialized = 0;
volatile TIME _InternalClock;
void PitSetFrequency(int frequency)
{
int divisor = 1193180/frequency; // Calculate the divisor
outportb(0x43, 0x36); // Set our command byte 0x36
outportb(0x40, divisor&0xFF); // Set low byte
outportb(0x40, divisor>>8); // Set high byte
ClockFrequency = frequency;
}
void i86_PitHandler(ISR_stack_regs *r)
{
ClockTicks++; // count tick
if (ClockTicks % ClockFrequency == 0)
_CLOCK_INC((TIME*)&_InternalClock); // update internal clock
}
unsigned int ClockSetTickCount(unsigned int i)
{
unsigned int r = ClockTicks;
ClockTicks = i;
return r;
}
unsigned int ClockGetTickCount()
{
return ClockTicks;
}
unsigned int PitGetFrequency()
{
return ClockFrequency;
}
void i86_PitInitialize(int freq)
{
PitSetFrequency(freq);
ClockTicks = 0;
i86_GetRTC((TIME*) &_InternalClock);
PitInitialized = 1;
}
TIME ClockGetTime()
{
return _InternalClock;
}
unsigned char PitIsInitialized()
{
return PitInitialized;
}
inline unsigned char CmosRead (unsigned char address)
{
outportb(0x70, address); iowait();
return inportb(0x71);
}
inline void CmosWrite (unsigned char address, unsigned char val)
{
outportb(0x70, address); iowait();
outportb(0x71, val);
}
void i86_SetRTC (const TIME* time)
{
unsigned char BCD = ((CmosRead(0x0b)&4)==0) ? 1 : 0;
unsigned char ampm = ((CmosRead(0x0b)&2)==0) ? 1 : 0;
CmosWrite (0, (BCD) ? (time->second%10) | (time->second/10*16) : time->second); // Seconds
CmosWrite (2, (BCD) ? (time->minute%10) | (time->minute/10*16) : time->minute); // Minutes
if (ampm && time->hour > 12) // Hours
CmosWrite (4, (BCD) ? (((time->hour - 12) % 10) | ((time->hour - 12)/10*16) | 0x80) : (time->hour | 0x80) );
else if (ampm && time->hour == 0) // Midnight convention: 12 PM = 00:00
CmosWrite (4, (BCD) ? 0x92 : 0x8C);
else CmosWrite (4, (BCD) ? (time->hour%10) | (time->hour/10*16) : time->hour); // 24h / AM
CmosWrite (6, (BCD) ? (time->weekday%10) | (time->weekday/10*16) : time->weekday); // Weekday
CmosWrite (7, (BCD) ? (time->day%10) | (time->day/10*16) : time->day); // Day
CmosWrite (8, (BCD) ? (time->month%10) | (time->month/10*16) : time->month); // Month
CmosWrite (9, (BCD) ? (time->year%10) | (time->year/10*16) : time->year); // Year
CmosWrite (0x32, (BCD) ? (time->century%10) | (time->century/10*16) : time->century); // Century
}
void i86_GetRTC(TIME* tim)
{
unsigned char BCD = ((CmosRead(0x0b)&4)==0) ? 1 : 0;
unsigned char am_pm = ((CmosRead(0x0b)&2)==0) ? 1 : 0;
tim->second = (BCD) ? (CmosRead(0x00)%16) + 10*(CmosRead(0x00)/16): CmosRead(0x00);
tim->minute = (BCD) ? (CmosRead(0x02)%16) + 10*(CmosRead(0x02)/16): CmosRead(0x02);
// Time is PM
if (am_pm && CmosRead(0x04)&80) {
tim->hour = (BCD) ? ((CmosRead(0x04)-0x80)%16) + 10*((CmosRead(0x04)-0x80)/16): CmosRead(0x04)-0x80;
tim->hour += 12;
}
// 24Hour format, or AM
else tim->hour = (BCD) ? (CmosRead(0x04)%16) + 10*(CmosRead(0x04)/16): CmosRead(0x04);
tim->weekday = (BCD) ? (CmosRead(0x06)%16) + 10*(CmosRead(0x06)/16): CmosRead(0x06);
tim->day = (BCD) ? (CmosRead(0x07)%16) + 10*(CmosRead(0x07)/16): CmosRead(0x07);
tim->month = (BCD) ? (CmosRead(0x08)%16) + 10*(CmosRead(0x08)/16): CmosRead(0x08);
tim->year = (BCD) ? (CmosRead(0x09)%16) + 10*(CmosRead(0x09)/16): CmosRead(0x09);
tim->century = (BCD) ? (CmosRead(0x32)%16) + 10*(CmosRead(0x32)/16): CmosRead(0x32);
}