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/*  ckinit.c

 *

 *  This file provides a template for the clock device driver initialization.

 *

 *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.

 *  On-Line Applications Research Corporation (OAR).

 *  All rights assigned to U.S. Government, 1994.

 *

 *  This material may be reproduced by or for the U.S. Government pursuant

 *  to the copyright license under the clause at DFARS 252.227-7013.  This

 *  notice must appear in all copies of this file and its derivatives.

 *

 *  $Id: ckinit.c,v 1.2 2001-09-27 12:01:19 chris Exp $

 */

#ifndef lint

static char _sccsid[] = "@(#)ckinit.c 03/15/96     1.1\n";

#endif

#include <stdlib.h>

#include <rtems.h>

#include <rtems/libio.h>

#include <bsp.h>

#include "clock.h"

#define CLOCKS_PER_MICROSECOND ( CPU_CLOCK_RATE_MHZ ) /* equivalent to CPU clock speed in MHz */

void Clock_exit( void );

rtems_isr Clock_isr( rtems_vector_number vector );

/*

 *  The interrupt vector number associated with the clock tick device

 *  driver.

 */

#define CLOCK_VECTOR         14

/*

 *  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;

/*

 *  The previous ISR on this clock tick interrupt vector.

 */

rtems_isr_entry  Old_ticker;

void Clock_exit( void );

static unsigned32 a29k_timer_rate = 0;

/*

 *  Isr Handler

 */

rtems_isr Clock_isr(

  rtems_vector_number vector

)

{

/*

 * bump the number of clock driver ticks since initialization

 *

 * determine if it is time to announce the passing of tick as configured

 * to RTEMS through the rtems_clock_tick directive

 *

 * perform any timer dependent tasks

 */

  a29k_clear_timer();

  Clock_driver_ticks += 1;

  rtems_clock_tick();

}

/* User callback shell (set from Clock_Control) */

static void (*user_callback)(void);

rtems_isr User_Clock_isr(

  rtems_vector_number vector

)

{

   /* refresh the internal CPU timer */

  a29k_clear_timer();

   if (user_callback)

      user_callback();

}

/*

 *  Install_clock

 *

 *  Install a clock tick handler and reprograms the chip.  This

 *  is used to initially establish the clock tick.

 */

void Install_clock(

  rtems_isr_entry clock_isr

)

{

  /*

   *  Initialize the clock tick device driver variables

   */

  Clock_driver_ticks = 0;

  /*

   *  If ticks_per_timeslice is configured as non-zero, then the user

   *  wants a clock tick.

   */

  if ( BSP_Configuration.ticks_per_timeslice ) {

    Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );

    /*

     *  Hardware specific initialize goes here

     */

    a29k_timer_rate = BSP_Configuration.microseconds_per_tick * CLOCKS_PER_MICROSECOND;

    a29k_init_timer( a29k_timer_rate );

  }

  /*

   *  Schedule the clock cleanup routine to execute if the application exits.

   */

  atexit( Clock_exit );

}

/*

 *  Clean up before the application exits

 */

void Clock_exit( void )

{

  if ( BSP_Configuration.ticks_per_timeslice ) {

    /* a29k: turn off the timer interrupts */

    a29k_disable_timer();

  }

}

/*

 *  Clock_initialize

 *

 *  Device driver entry point for clock tick driver initialization.

 */

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;

}

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 == 0)

        goto done;

    /*

     * 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 );

      user_callback = (void (*)(void))args->buffer;

      (void) set_vector( User_Clock_isr, CLOCK_VECTOR, 1 );

      rtems_interrupt_enable( isrlevel );

    }

done:

    return RTEMS_SUCCESSFUL;

}