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/*  ckinit.c

 *

 *  This file contains the clock driver initialization for the IDT 4650.

 *

 *  Author:     Craig Lebakken <craigl@transition.com>

 *

 *  COPYRIGHT (c) 1996 by Transition Networks Inc.

 *

 *  To anyone who acknowledges that this file is provided "AS IS"

 *  without any express or implied warranty:

 *      permission to use, copy, modify, and distribute this file

 *      for any purpose is hereby granted without fee, provided that

 *      the above copyright notice and this notice appears in all

 *      copies, and that the name of Transition Networks not be used in

 *      advertising or publicity pertaining to distribution of the

 *      software without specific, written prior permission.

 *      Transition Networks makes no representations about the suitability

 *      of this software for any purpose.

 *

 *  Derived from c/src/lib/libbsp/no_cpu/no_bsp/clock/ckinit.c:

 *

 *  COPYRIGHT (c) 1989-1999.

 *  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.

 *

 *  $Id: ckinit.c,v 1.2 2001-09-27 12:01:22 chris Exp $

 */

/*

 *  Rather than deleting this, it is commented out to (hopefully) help

 *  the submitter send updates.

 *

 *  static char _sccsid[] = "@(#)ckinit.c 08/20/96     1.3\n";

 */

#include <stdlib.h>

#include <rtems.h>

#include <rtems/libio.h>

#define EXT_INT5    0x8000  /* external interrupt 5 */

#include "clock.h"

/* formerly in the BSP */

#if 0

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

#endif

#define CLOCKS_PER_MICROSECOND \

  rtems_cpu_configuration_get_clicks_per_microsecond()

/* to avoid including the bsp */

mips_isr_entry set_vector( rtems_isr_entry, rtems_vector_number, int );

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_MASK    EXT_INT5

#define CLOCK_VECTOR         0x7

/*

 *  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;

/*

 *  Clock_isrs is the number of clock ISRs until the next invocation of

 *  the RTEMS clock tick routine.  The clock tick device driver

 *  gets an interrupt once a millisecond and counts down until the

 *  length of time between the user configured microseconds per tick

 *  has passed.

 */

rtems_unsigned32 Clock_isrs;              /* ISRs until next tick */

/*

 * 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 mips_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

 */

  /* refresh the internal CPU timer */

  mips_set_timer( mips_timer_rate );

  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 */

   mips_set_timer( mips_timer_rate );

   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;

  Clock_isrs = rtems_configuration_get_milliseconds_per_tick();

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

  /*

   *  Hardware specific initialize goes here

   */

  mips_timer_rate =

     rtems_configuration_get_microseconds_per_tick() * CLOCKS_PER_MICROSECOND;

  mips_set_timer( mips_timer_rate );

  enable_int(CLOCK_VECTOR_MASK);

  /*

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

   */

  atexit( Clock_exit );

}

/*

 *  Clean up before the application exits

 */

void Clock_exit( void )

{

  /* mips: turn off the timer interrupts */

  disable_int(~CLOCK_VECTOR_MASK);

}

/*

 *  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;

}