//
// Created by rick on 9/22/19.
//

#include "timer.h"

#include <drivers/ports.h>
#include <cpu/isr.h>

u32 tick = 0;

static void timer_callback(registers_t regs) {
    tick++;
}

int init_timer(u32 freq) {
    register_interrupt_handler(IRQ0, timer_callback);

    u32 divisor = 1193180 / freq;
    u8 low = (u8) (divisor & 0xFF);
    u8 high = (u8) ((divisor >> 8) & 0xFF);
    port_byte_out(PORT_PIT_COMMAND, PIT_MODE_BIN | PIT_MODE_SQUARE_WAVE | PIT_ACCESS_MODE_HL | PIT_CHANNEL_0);
    port_byte_out(PORT_PIT_DATA_0, low);
    port_byte_out(PORT_PIT_DATA_0, high);
    return 0;
}