Subversion Repositories HelenOS-historic

/*

 * Copyright (C) 2005 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/** Interval Timer driver. */

#include <arch/drivers/it.h>

#include <arch/drivers/keyboard.h>

#include <arch/interrupt.h>

#include <arch/register.h>

#include <arch/asm.h>

#include <arch/barrier.h>

#include <time/clock.h>

/** Initialize Interval Timer. */

void it_init(void)

{

    cr_itv_t itv;

    /* initialize Interval Timer external interrupt vector */

    itv.value = itv_read();

    itv.vector = INTERRUPT_TIMER;

    itv.m = 0;

    itv_write(itv.value);

    /* set Interval Timer Counter to zero */

    itc_write(0);

    /* generate first Interval Timer interrupt in IT_DELTA ticks */

    itm_write(IT_DELTA);

    /* propagate changes */

    srlz_d();

}

/** Process Interval Timer interrupt. */

void it_interrupt(void)

{

    eoi_write(EOI);

    itm_write(itc_read() + IT_DELTA);   /* program next interruption */

    srlz_d();               /* propagate changes */

    clock();

    poll_keyboard();

}