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//==========================================================================

//

//      hal_intr.c

//

//      PowerPC interrupt handlers

//

//==========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

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//####ECOSGPLCOPYRIGHTEND####

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):    jskov

// Contributors: jskov

// Date:         1999-02-20

// Purpose:      PowerPC interrupt handlers

// Description:  This file contains code to handle interrupt related issues

//               on the PowerPC.

//

//####DESCRIPTIONEND####

//

//==========================================================================

#include <pkgconf/hal.h>

#include <cyg/hal/hal_intr.h>

externC void

hal_IRQ_init(void)

{

    // No architecture general initialization, but the variant may have

    // provided some.

    hal_variant_IRQ_init();

    // Initialize real-time clock (for delays, etc, even if kernel doesn't use it)

    HAL_CLOCK_INITIALIZE(CYGNUM_HAL_RTC_PERIOD);

}

// Delay for some number of useconds.

externC void

hal_delay_us(int us)

{

    cyg_int32 old_dec, new_dec;

    long ticks;

    int diff;

    // Note: the system constant CYGNUM_HAL_RTC_PERIOD corresponds to 10,000us

    // Scale the desired number of microseconds to be a number of decrementer ticks

    ticks = ((long long)us * (CYGNUM_HAL_RTC_PERIOD * 100)) / 1000000;

    asm volatile("mfdec  %0;" : "=r"(old_dec) : );

    while (ticks > 0) {

        do {

            asm volatile("mfdec  %0;" : "=r"(new_dec) : );

        } while (old_dec == new_dec);

        if (new_dec < 0) {

            HAL_CLOCK_RESET(0, CYGNUM_HAL_RTC_PERIOD);

        }

        diff = (old_dec - new_dec);

        if (diff < 1) diff = 1;

        old_dec = new_dec;

        ticks -= diff;

    }

}

// -------------------------------------------------------------------------

// EOF hal_intr.c