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/*

 *  Clock Tick Device Driver

 *

 *  This routine initializes the Real Time Clock Counter Timer which is

 *  part of the MEC on the ERC32 CPU.

 *

 *  The tick frequency is directly programmed to the configured number of

 *  microseconds per tick.

 *

 *  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.

 *

 *  Ported to ERC32 implementation of the SPARC by On-Line Applications

 *  Research Corporation (OAR) under contract to the European Space

 *  Agency (ESA).

 *

 *  ERC32 modifications of respective RTEMS file: COPYRIGHT (c) 1995.

 *  European Space Agency.

 *

 *  $Id: ckinit.c,v 1.2 2001-09-27 12:01:13 chris Exp $

 */

#include <stdlib.h>

#include <bsp.h>

#include <rtems/libio.h>

/*

 *  The Real Time Clock Counter Timer uses this trap type.

 */

#define CLOCK_VECTOR ERC32_TRAP_TYPE( ERC32_INTERRUPT_REAL_TIME_CLOCK )

/*

 *  Clock ticks since initialization

 */

volatile rtems_unsigned32 Clock_driver_ticks;

/*

 *  This is the value programmed into the count down timer.  It

 *  is artificially lowered when SIMSPARC_FAST_IDLE is defined to

 *  cut down how long we spend in the idle task while executing on

 *  the simulator.

 */

extern rtems_unsigned32 CPU_SPARC_CLICKS_PER_TICK;

rtems_isr_entry  Old_ticker;

void Clock_exit( void );

/*

 * These are set by clock driver during its init

 */

rtems_device_major_number rtems_clock_major = ~0;

rtems_device_minor_number rtems_clock_minor;

/*

 *  Clock_isr

 *

 *  This is the clock tick interrupt handler.

 *

 *  Input parameters:

 *    vector - vector number

 *

 *  Output parameters:  NONE

 *

 *  Return values:      NONE

 *

 */

rtems_isr Clock_isr(

  rtems_vector_number vector

)

{

  /*

   *  If we are in "fast idle" mode, then the value for clicks per tick

   *  is lowered to decrease the amount of time spent executing the idle

   *  task while using the SPARC Instruction Simulator.

   */

#if SIMSPARC_FAST_IDLE

  ERC32_MEC.Real_Time_Clock_Counter = CPU_SPARC_CLICKS_PER_TICK;

  ERC32_MEC_Set_Real_Time_Clock_Timer_Control(

    ERC32_MEC_TIMER_COUNTER_ENABLE_COUNTING |

      ERC32_MEC_TIMER_COUNTER_LOAD_COUNTER

  );

#endif

  /*

   *  The driver has seen another tick.

   */

  Clock_driver_ticks += 1;

  /*

   *  Real Time Clock counter/timer is set to automatically reload.

   */

  rtems_clock_tick();

}

/*

 *  Install_clock

 *

 *  This routine actually performs the hardware initialization for the clock.

 *

 *  Input parameters:

 *    clock_isr - clock interrupt service routine entry point

 *

 *  Output parameters:  NONE

 *

 *  Return values:      NONE

 *

 */

extern int CLOCK_SPEED;

void Install_clock(

  rtems_isr_entry clock_isr

)

{

  Clock_driver_ticks = 0;

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

  /* approximately 1 us per countdown */

  ERC32_MEC.Real_Time_Clock_Scalar  = CLOCK_SPEED - 1;

  ERC32_MEC.Real_Time_Clock_Counter = CPU_SPARC_CLICKS_PER_TICK;

  ERC32_MEC_Set_Real_Time_Clock_Timer_Control(

    ERC32_MEC_TIMER_COUNTER_ENABLE_COUNTING |

      ERC32_MEC_TIMER_COUNTER_LOAD_SCALER |

      ERC32_MEC_TIMER_COUNTER_LOAD_COUNTER

  );

  ERC32_MEC_Set_Real_Time_Clock_Timer_Control(

    ERC32_MEC_TIMER_COUNTER_ENABLE_COUNTING |

      ERC32_MEC_TIMER_COUNTER_RELOAD_AT_ZERO

  );

  atexit( Clock_exit );

}

/*

 *  Clock_exit

 *

 *  This routine allows the clock driver to exit by masking the interrupt and

 *  disabling the clock's counter.

 *

 *  Input parameters:   NONE

 *

 *  Output parameters:  NONE

 *

 *  Return values:      NONE

 *

 */

void Clock_exit( void )

{

  ERC32_Mask_interrupt( ERC32_INTERRUPT_REAL_TIME_CLOCK );

  ERC32_MEC_Set_Real_Time_Clock_Timer_Control(

    ERC32_MEC_TIMER_COUNTER_DISABLE_COUNTING

  );

  /* do not restore old vector */

}

/*

 *  Clock_initialize

 *

 *  This routine initializes the clock driver.

 *

 *  Input parameters:

 *    major - clock device major number

 *    minor - clock device minor number

 *    parg  - pointer to optional device driver arguments

 *

 *  Output parameters:  NONE

 *

 *  Return values:

 *    rtems_device_driver 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

 *

 *  This routine is the clock device driver control entry point.

 *

 *  Input parameters:

 *    major - clock device major number

 *    minor - clock device minor number

 *    parg  - pointer to optional device driver arguments

 *

 *  Output parameters:  NONE

 *

 *  Return values:

 *    rtems_device_driver 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 == 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 );

       (void) set_vector( args->buffer, CLOCK_VECTOR, 1 );

      rtems_interrupt_enable( isrlevel );

    }

done:

    return RTEMS_SUCCESSFUL;

}