/*
 * VBMouse - Programmable Interrupt Controller routines
 * Copyright (C) 2022 Javier S. Pedro
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#ifndef PIC_H
#define PIC_H

#include <conio.h>

// TODO Currently do not support secondary PIC

enum {
	PIC1_CMD_IOPORT = 0x20,
	PIC1_DATA_IOPORT = PIC1_CMD_IOPORT+1,
	PIC2_CMD_IOPORT = 0xA0,
	PIC2_DATA_IOPORT = PIC2_CMD_IOPORT+1,
};

enum PIC_CMDS {
	/** End-Of-Interrupt command. */
	PIC_CMD_EOI = 0x20
};

static void pic_mask_irq(unsigned irq)
{
	uint8_t mask = inp(PIC1_DATA_IOPORT);
	mask |=  (1 << irq);
	outp(PIC1_DATA_IOPORT, mask);
}

static void pic_unmask_irq(unsigned irq)
{
	uint8_t mask = inp(PIC1_DATA_IOPORT);
	mask &= ~(1 << irq);
	outp(PIC1_DATA_IOPORT, mask);
}

static void pic_eoi_irq(unsigned irq)
{
	(void) irq;
	outp(PIC1_CMD_IOPORT, PIC_CMD_EOI);
}

#endif // PIC_H