k-tana-zero/k/pic/pit.c

#include "io.h"
#include "pit.h"

static uint64_t counter = 0;

void pit_handler(void)
{
    counter++;
}

void init_pit(void)
{
    // write to control register
    outb(PIT_CONTROL_REG, PIT_SET_COUNTER_0 | PIT_MODE_2 | PIT_RW_LSB_MSB);

    // write frequency
    outb(PIT_COUNTER_0, DIVIDER_LO);
    outb(PIT_COUNTER_0, DIVIDER_HI);
}

uint64_t gettick(void)
{
    return counter;
}