mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-26 06:30:39 +00:00
132 lines
3 KiB
C
132 lines
3 KiB
C
/*
|
|
* (C) Copyright 2009
|
|
* Graeme Russ, <graeme.russ@gmail.com>
|
|
*
|
|
* (C) Copyright 2002
|
|
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
|
|
*
|
|
* See file CREDITS for list of people who contributed to this
|
|
* project.
|
|
*
|
|
* 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., 59 Temple Place, Suite 330, Boston,
|
|
* MA 02111-1307 USA
|
|
*/
|
|
|
|
/*
|
|
* This file provides the interrupt handling functionality for systems
|
|
* based on the standard PC/AT architecture using two cascaded i8259
|
|
* Programmable Interrupt Controllers.
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <asm/io.h>
|
|
#include <asm/i8259.h>
|
|
#include <asm/ibmpc.h>
|
|
#include <asm/interrupt.h>
|
|
|
|
#if CONFIG_SYS_NUM_IRQS != 16
|
|
#error "CONFIG_SYS_NUM_IRQS must equal 16 if CONFIG_SYS_NUM_IRQS is defined"
|
|
#endif
|
|
|
|
int interrupt_init(void)
|
|
{
|
|
u8 i;
|
|
|
|
disable_interrupts();
|
|
|
|
/* Mask all interrupts */
|
|
outb(0xff, MASTER_PIC + IMR);
|
|
outb(0xff, SLAVE_PIC + IMR);
|
|
|
|
/* Master PIC */
|
|
/* Place master PIC interrupts at INT20 */
|
|
/* ICW3, One slave PIC is present */
|
|
outb(ICW1_SEL|ICW1_EICW4, MASTER_PIC + ICW1);
|
|
outb(0x20, MASTER_PIC + ICW2);
|
|
outb(IR2, MASTER_PIC + ICW3);
|
|
outb(ICW4_PM, MASTER_PIC + ICW4);
|
|
|
|
for (i = 0; i < 8; i++)
|
|
outb(OCW2_SEOI | i, MASTER_PIC + OCW2);
|
|
|
|
/* Slave PIC */
|
|
/* Place slave PIC interrupts at INT28 */
|
|
/* Slave ID */
|
|
outb(ICW1_SEL|ICW1_EICW4, SLAVE_PIC + ICW1);
|
|
outb(0x28, SLAVE_PIC + ICW2);
|
|
outb(0x02, SLAVE_PIC + ICW3);
|
|
outb(ICW4_PM, SLAVE_PIC + ICW4);
|
|
|
|
for (i = 0; i < 8; i++)
|
|
outb(OCW2_SEOI | i, SLAVE_PIC + OCW2);
|
|
|
|
/*
|
|
* Enable cascaded interrupts by unmasking the cascade IRQ pin of
|
|
* the master PIC
|
|
*/
|
|
unmask_irq(2);
|
|
|
|
enable_interrupts();
|
|
|
|
return 0;
|
|
}
|
|
|
|
void mask_irq(int irq)
|
|
{
|
|
int imr_port;
|
|
|
|
if (irq >= CONFIG_SYS_NUM_IRQS)
|
|
return;
|
|
|
|
if (irq > 7)
|
|
imr_port = SLAVE_PIC + IMR;
|
|
else
|
|
imr_port = MASTER_PIC + IMR;
|
|
|
|
outb(inb(imr_port) | (1 << (irq & 7)), imr_port);
|
|
}
|
|
|
|
void unmask_irq(int irq)
|
|
{
|
|
int imr_port;
|
|
|
|
if (irq >= CONFIG_SYS_NUM_IRQS)
|
|
return;
|
|
|
|
if (irq > 7)
|
|
imr_port = SLAVE_PIC + IMR;
|
|
else
|
|
imr_port = MASTER_PIC + IMR;
|
|
|
|
outb(inb(imr_port) & ~(1 << (irq & 7)), imr_port);
|
|
}
|
|
|
|
void specific_eoi(int irq)
|
|
{
|
|
if (irq >= CONFIG_SYS_NUM_IRQS)
|
|
return;
|
|
|
|
if (irq > 7) {
|
|
/*
|
|
* IRQ is on the slave - Issue a corresponding EOI to the
|
|
* slave PIC and an EOI for IRQ2 (the cascade interrupt)
|
|
* on the master PIC
|
|
*/
|
|
outb(OCW2_SEOI | (irq & 7), SLAVE_PIC + OCW2);
|
|
irq = SEOI_IR2;
|
|
}
|
|
|
|
outb(OCW2_SEOI | irq, MASTER_PIC + OCW2);
|
|
}
|