drivers/interrupt_controller/i8259.c

/*
 * Copyright (c) 2010-2015 Wind River Systems, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * @file
 * @brief Disable Intel 8259A PIC (Programmable Interrupt Controller)
 *
 * This module disables the Intel 8259A PIC (Programmable Interrupt Controller)
 * to prevent it from generating spurious interrupts.
 */


#include <nanokernel.h>
#include <arch/cpu.h>
#include <toolchain.h>
#include <sections.h>
#include <device.h>
#include <init.h>

#include <board.h>

/* programmable interrupt controller info (pair of cascaded 8259A devices) */
#define PIC_MASTER_BASE_ADRS 0x20
#define PIC_SLAVE_BASE_ADRS 0xa0
#define PIC_REG_ADDR_INTERVAL 1

/* register definitions */
#define PIC_ADRS(baseAdrs, reg) (baseAdrs + (reg * PIC_REG_ADDR_INTERVAL))

#define PIC_PORT2(base) PIC_ADRS(base, 0x01) /* port 2 */

#define PIC_DISABLE 0xff /* Disable PIC command */

/**
 *
 * @brief Initialize the Intel 8259A PIC device driver
 *
 * This routine disables the 8259A PIC device to prevent it from
 * generating spurious interrupts.
 *
 * @return N/A
 */

int _i8259_init(struct device *unused)
{
	ARG_UNUSED(unused);
	sys_out8(PIC_DISABLE, PIC_PORT2(PIC_SLAVE_BASE_ADRS));
	sys_out8(PIC_DISABLE, PIC_PORT2(PIC_MASTER_BASE_ADRS));
	return 0;
}

SYS_INIT(_i8259_init, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);