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/*

 * The irq controller for vrc5476.

 *

 * Copyright (C) 2001 MontaVista Software Inc.

 * Author: jsun@mvista.com or jsun@junsun.net

 *

 * 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/init.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/types.h>

#include <linux/ptrace.h>

#include <asm/system.h>

#include <asm/ddb5xxx/ddb5xxx.h>

static int irq_base;

static void vrc5476_irq_enable(uint irq)

{

        nile4_enable_irq(irq - irq_base);

}

static void vrc5476_irq_disable(uint irq)

{

        nile4_disable_irq(irq - irq_base);

}

static unsigned int vrc5476_irq_startup(uint irq)

{

        nile4_enable_irq(irq - irq_base);

        return 0;

}

#define vrc5476_irq_shutdown    vrc5476_irq_disable

static void vrc5476_irq_ack(uint irq)

{

        nile4_clear_irq(irq - irq_base);

        nile4_disable_irq(irq - irq_base);

}

static void vrc5476_irq_end(uint irq)

{

        if(!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))

                vrc5476_irq_enable(irq);

}

static hw_irq_controller vrc5476_irq_controller = {

        "vrc5476",

        vrc5476_irq_startup,

        vrc5476_irq_shutdown,

        vrc5476_irq_enable,

        vrc5476_irq_disable,

        vrc5476_irq_ack,

        vrc5476_irq_end,

        NULL                            /* no affinity stuff for UP */

};

void __init

vrc5476_irq_init(u32 base)

{

        extern irq_desc_t irq_desc[];

        u32 i;

        irq_base = base;

        for (i= base; i< base + NUM_VRC5476_IRQ; i++) {

                irq_desc[i].status = IRQ_DISABLED;

                irq_desc[i].action = NULL;

                 irq_desc[i].depth = 1;

                 irq_desc[i].handler = &vrc5476_irq_controller;

        }

}

asmlinkage void

vrc5476_irq_dispatch(struct pt_regs *regs)

{

        extern void spurious_interrupt(void);

        u32 mask;

        int nile4_irq;

        mask = nile4_get_irq_stat(0);

        /* quick check for possible time interrupt */

        if (mask & (1 << VRC5476_IRQ_GPT)) {

                do_IRQ(VRC5476_IRQ_BASE + VRC5476_IRQ_GPT, regs);

                return;

        }

        /* check for i8259 interrupts */

        if (mask & (1 << VRC5476_I8259_CASCADE)) {

                int i8259_irq = nile4_i8259_iack();

                do_IRQ(I8259_IRQ_BASE + i8259_irq, regs);

                return;

        }

        /* regular nile4 interrupts (we should not really have any */

        for (nile4_irq = 0; mask; nile4_irq++, mask >>= 1) {

                if (mask & 1) {

                        do_IRQ(VRC5476_IRQ_BASE + nile4_irq, regs);

                        return;

                }

        }

        spurious_interrupt();

}