pic.c

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/*
 * Copyright 2008 Freescale Semiconductor, Inc.
 *
 * 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.
 */

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/of_platform.h>

#include <asm/mpic.h>
#include <asm/i8259.h>

#ifdef CONFIG_PPC_I8259
static void mpc86xx_8259_cascade(unsigned int irq, struct irq_desc *desc)
{
    struct irq_chip *chip = irq_desc_get_chip(desc);
    unsigned int cascade_irq = i8259_irq();

    if (cascade_irq != NO_IRQ)
        generic_handle_irq(cascade_irq);

    chip->irq_eoi(&desc->irq_data);
}
#endif  /* CONFIG_PPC_I8259 */

void __init mpc86xx_init_irq(void)
{
#ifdef CONFIG_PPC_I8259
    struct device_node *np;
    struct device_node *cascade_node = NULL;
    int cascade_irq;
#endif

    struct mpic *mpic = mpic_alloc(NULL, 0, MPIC_BIG_ENDIAN |
            MPIC_SINGLE_DEST_CPU,
            0, 256, " MPIC     ");
    BUG_ON(mpic == NULL);

    mpic_init(mpic);

#ifdef CONFIG_PPC_I8259
    /* Initialize i8259 controller */
    for_each_node_by_type(np, "interrupt-controller")
        if (of_device_is_compatible(np, "chrp,iic")) {
            cascade_node = np;
            break;
        }

    if (cascade_node == NULL) {
        printk(KERN_DEBUG "Could not find i8259 PIC\n");
        return;
    }

    cascade_irq = irq_of_parse_and_map(cascade_node, 0);
    if (cascade_irq == NO_IRQ) {
        printk(KERN_ERR "Failed to map cascade interrupt\n");
        return;
    }

    i8259_init(cascade_node, 0);
    of_node_put(cascade_node);

    irq_set_chained_handler(cascade_irq, mpc86xx_8259_cascade);
#endif
}