mirror of
https://github.com/AsahiLinux/u-boot
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132 lines
3 KiB
C
132 lines
3 KiB
C
/*
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* (C) Copyright 2009
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* Graeme Russ, <graeme.russ@gmail.com>
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*
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* (C) Copyright 2002
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* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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/*
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* This file provides the interrupt handling functionality for systems
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* based on the standard PC/AT architecture using two cascaded i8259
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* Programmable Interrupt Controllers.
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*/
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#include <common.h>
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#include <asm/io.h>
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#include <asm/i8259.h>
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#include <asm/ibmpc.h>
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#include <asm/interrupt.h>
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#if CONFIG_SYS_NUM_IRQS != 16
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#error "CONFIG_SYS_NUM_IRQS must equal 16 if CONFIG_SYS_NUM_IRQS is defined"
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#endif
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int interrupt_init(void)
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{
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u8 i;
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disable_interrupts();
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/* Mask all interrupts */
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outb(0xff, MASTER_PIC + IMR);
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outb(0xff, SLAVE_PIC + IMR);
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/* Master PIC */
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/* Place master PIC interrupts at INT20 */
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/* ICW3, One slave PIC is present */
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outb(ICW1_SEL|ICW1_EICW4, MASTER_PIC + ICW1);
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outb(0x20, MASTER_PIC + ICW2);
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outb(IR2, MASTER_PIC + ICW3);
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outb(ICW4_PM, MASTER_PIC + ICW4);
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for (i = 0; i < 8; i++)
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outb(OCW2_SEOI | i, MASTER_PIC + OCW2);
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/* Slave PIC */
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/* Place slave PIC interrupts at INT28 */
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/* Slave ID */
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outb(ICW1_SEL|ICW1_EICW4, SLAVE_PIC + ICW1);
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outb(0x28, SLAVE_PIC + ICW2);
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outb(0x02, SLAVE_PIC + ICW3);
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outb(ICW4_PM, SLAVE_PIC + ICW4);
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for (i = 0; i < 8; i++)
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outb(OCW2_SEOI | i, SLAVE_PIC + OCW2);
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/*
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* Enable cascaded interrupts by unmasking the cascade IRQ pin of
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* the master PIC
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*/
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unmask_irq(2);
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enable_interrupts();
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return 0;
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}
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void mask_irq(int irq)
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{
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int imr_port;
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if (irq >= CONFIG_SYS_NUM_IRQS)
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return;
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if (irq > 7)
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imr_port = SLAVE_PIC + IMR;
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else
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imr_port = MASTER_PIC + IMR;
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outb(inb(imr_port) | (1 << (irq & 7)), imr_port);
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}
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void unmask_irq(int irq)
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{
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int imr_port;
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if (irq >= CONFIG_SYS_NUM_IRQS)
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return;
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if (irq > 7)
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imr_port = SLAVE_PIC + IMR;
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else
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imr_port = MASTER_PIC + IMR;
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outb(inb(imr_port) & ~(1 << (irq & 7)), imr_port);
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}
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void specific_eoi(int irq)
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{
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if (irq >= CONFIG_SYS_NUM_IRQS)
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return;
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if (irq > 7) {
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/*
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* IRQ is on the slave - Issue a corresponding EOI to the
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* slave PIC and an EOI for IRQ2 (the cascade interrupt)
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* on the master PIC
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*/
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outb(OCW2_SEOI | (irq & 7), SLAVE_PIC + OCW2);
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irq = SEOI_IR2;
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}
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outb(OCW2_SEOI | irq, MASTER_PIC + OCW2);
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}
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