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/*

 *  Clock Driver for SH4 simulator (timer interrupt not supported now).

 *

 *  Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia

 *  Author: Victor V. Vengerov <vvv@oktet.ru>

 *

 *  COPYRIGHT (c) 1989-2001.

 *  On-Line Applications Research Corporation (OAR).

 *

 *  The license and distribution terms for this file may be

 *  found in the file LICENSE in this distribution or at

 *

 *  http://www.OARcorp.com/rtems/license.html.

 *

 *  ckinit.c,v 1.1 2001/10/11 21:04:35 joel Exp

 */

#include <stdlib.h>

#include <bsp.h>

#include <rtems/libio.h>

/*

 * Clock_driver_ticks is a monotonically increasing counter of the

 * number of clock ticks since the driver was initialized.

 */

volatile rtems_unsigned32 Clock_driver_ticks;

/*

 * These are set by clock driver during its init

 */

rtems_device_major_number rtems_clock_major = ~0;

rtems_device_minor_number rtems_clock_minor;

rtems_isr (*rtems_clock_hook)(rtems_vector_number) = NULL;

static void

set_clock_period(rtems_unsigned32 period)

{

    asm volatile ("\tmov %0,r0\n"

                  "\ttrapa\t#4\n"

                  :

                  : "r" (period)

                  : "r0" );

}

/* Clock_isr --

 *     This handles the timer interrupt by clearing the timer's interrupt

 *     flag and announcing the clock tick to the system.

 *

 * PARAMETERS:

 *     vector - timer interrupt vector number

 *

 * RETURNS:

 *     none

 */

rtems_isr

Clock_isr (rtems_vector_number vector)

{

    /* Announce the clock tick */

    Clock_driver_ticks++;

    rtems_clock_tick();

}

/* Clock_exit --

 *     This shuts down the timer if it was enabled and removes it

 *     from the interrupt mask.

 *

 * PARAMETERS:

 *     none

 *

 * RETURNS:

 *     none

 */

void

Clock_exit(void)

{

    if (BSP_Configuration.ticks_per_timeslice)

    {

        /* disable all timer1 interrupts */

        set_clock_period(0);

    }

}

/* Install_clock --

 *     This initialises timer1 with the BSP timeslice config value

 *     as a reference and sets up the interrupt handler for clock ticks.

 *

 * PARAMETERS:

 *     clock_isr - clock interrupt handler routine

 *

 * RETURNS:

 *     none.

 */

static void

Install_clock(rtems_isr_entry clock_isr)

{

    rtems_unsigned32 period;

    Clock_driver_ticks = 0;

    if (BSP_Configuration.ticks_per_timeslice)

    {

        void *old_isr;

        period = Cpu_table.clicks_per_second /

                 BSP_Configuration.ticks_per_timeslice;

        /* Configure timer interrupts */

        set_clock_period(period);

        /* Register the interrupt handler */

        rtems_interrupt_catch(clock_isr, CLOCK_VECTOR, &old_isr);

        /* Register the driver exit procedure so we can shutdown */

        atexit(Clock_exit);

    }

}

/* Clock_initialize --

 *     This is called to setup the clock driver. It calls the hardware

 *     setup function and make the driver major/minor values available

 *     for other.

 *

 * PARAMETERS:

 *     major - clock device major number

 *     minor - clock device minor number

 *     pargp - device driver initialization argument (not used)

 *

 * RETURNS:

 *     RTEMS status code

 */

rtems_device_driver

Clock_initialize(rtems_device_major_number major,

                 rtems_device_minor_number minor,

                 void *pargp)

{

    Install_clock (Clock_isr);

    /* Make major/minor avail to others such as shared memory driver */

    rtems_clock_major = major;

    rtems_clock_minor = minor;

    return RTEMS_SUCCESSFUL;

}

/* Clock_control --

 *     I/O control (IOCTL) function for Clock driver. At this moment this

 *     just runs the interrupt handler or re-registers the interrupt handler

 *     on request.

 *

 * PARAMETERS:

 *     major - clock major device number

 *     minor - clock minor device number

 *     pargp - pointer to IOCTL arguments

 *

 * RETURNS:

 *     RTEMS status code

 */

rtems_device_driver

Clock_control(rtems_device_major_number major,

              rtems_device_minor_number minor,

              void *pargp)

{

    rtems_unsigned32 isrlevel;

    rtems_libio_ioctl_args_t *args = pargp;

    if (args)

    {

        void *old_isr;

        /*

         * This is hokey, but until we get a defined interface

         * to do this, it will just be this simple...

         */

        if (args->command == rtems_build_name('I', 'S', 'R', ' '))

        {

            Clock_isr(CLOCK_VECTOR);

        }

        else if (args->command == rtems_build_name('N', 'E', 'W', ' '))

        {

            rtems_interrupt_disable( isrlevel );

            rtems_interrupt_catch(Clock_isr, CLOCK_VECTOR, &old_isr);

            rtems_interrupt_enable( isrlevel );

        }

    }

    return RTEMS_SUCCESSFUL;

}