#include "cpu/pic.h"
#include "cpu/io.h"

void pic_remap(uint8_t offset1, uint8_t offset2) {
    uint8_t a1, a2;
 
    a1 = inb(PIC1_DATA);                        // save masks
    a2 = inb(PIC2_DATA);
 
    outb(PIC1_COMMAND, ICW1_INIT | ICW1_ICW4);  // starts the initialization sequence (in cascade mode)
    io_wait();
    outb(PIC2_COMMAND, ICW1_INIT | ICW1_ICW4);
    io_wait();
    outb(PIC1_DATA, offset1);                 // ICW2: Master PIC vector offset
    io_wait();
    outb(PIC2_DATA, offset2);                 // ICW2: Slave PIC vector offset
    io_wait();
    outb(PIC1_DATA, 4);                       // ICW3: tell Master PIC that there is a slave PIC at IRQ2 (0000 0100)
    io_wait();
    outb(PIC2_DATA, 2);                       // ICW3: tell Slave PIC its cascade identity (0000 0010)
    io_wait();
 
    outb(PIC1_DATA, ICW4_8086);
    io_wait();
    outb(PIC2_DATA, ICW4_8086);
    io_wait();
 
    outb(PIC1_DATA, a1);   // restore saved masks.
    outb(PIC2_DATA, a2);
}

void pic_send_eoi(uint8_t irq)
{
	if(irq >= 8)
		outb(PIC2_COMMAND,PIC_EOI);
 
	outb(PIC1_COMMAND,PIC_EOI);
}

void pic_irq_set_mask(uint8_t IRQline) {
    uint16_t port;
    uint8_t value;
 
    if(IRQline < 8) {
        port = PIC1_DATA;
    } else {
        port = PIC2_DATA;
        IRQline -= 8;
    }
    value = inb(port) | (1 << IRQline);
    outb(port, value);        
}
 
void pic_irq_clear_mask(uint8_t IRQline) {
    uint16_t port;
    uint8_t value;
 
    if(IRQline < 8) {
        port = PIC1_DATA;
    } else {
        port = PIC2_DATA;
        IRQline -= 8;
    }
    value = inb(port) & ~(1 << IRQline);
    outb(port, value);        
}