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/*  Timer_init()

 *

 *  This routine initializes the Z8536 timer on the SQSIO4 SQUALL

 *  board for the CVME961 board.  The timer is setup to provide a

 *  tick every 1 millisecond.

 *

 *  Input parameters:  NONE

 *

 *  Output parameters:  NONE

 *

 *  NOTE: This routine will not work if the optimizer is enabled

 *        for most compilers.  The multiple writes to the Z8536

 *        will be optimized away.

 *

 *        It is important that the timer start/stop overhead be

 *        determined when porting or modifying this code.

 *

 *  COPYRIGHT (c) 1989-1997.

 *  On-Line Applications Research Corporation (OAR).

 *  Copyright assigned to U.S. Government, 1994.

 *

 *  The license and distribution terms for this file may in

 *  the file LICENSE in this distribution or at

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

 *

 *  $Id: timer.c,v 1.2 2001-09-27 12:00:00 chris Exp $

 */

#include <rtems.h>

#include <bsp.h>

#include <stdlib.h>

#include <i960RP.h>

#include <rtems/libio.h>

#define TIMER_VECTOR 34

int Ttimer_val;

rtems_boolean Timer_driver_Find_average_overhead = 0;

void flush_reg();

rtems_isr timerisr();

void Timer_initialize()

{

  volatile unsigned int *tmr1 = (unsigned int *) TMR1_ADDR;

  volatile unsigned int *trr1 = (unsigned int *) TRR1_ADDR;

  volatile unsigned int *tcr1 = (unsigned int *) TCR1_ADDR;

  volatile unsigned int *imsk = (unsigned int *) IMSK_ADDR;

  volatile unsigned int *icon = (unsigned int *) ICON_ADDR;

  volatile unsigned int *ipnd = (unsigned int *) IPND_ADDR;

  volatile unsigned int *imap2 = (unsigned int *) IMAP2_ADDR;

    #define BUS_CLOCK_1 0

    #define TMR_WRITE_CNTL 8

    #define TMR_AUTO_RELOAD 4

    #define TMR_ENABLE 2

    #define TMR_TERM_CNT_STAT 1

    *tmr1 = BUS_CLOCK_1 | TMR_AUTO_RELOAD;

     *icon = 0x6000;

    set_vector( (((unsigned int) timerisr) | 0x2), TIMER_VECTOR, 1 );

    *imap2 = (*imap2 & 0xff0fffff) | (((TIMER_VECTOR >> 4) & 0xf) << 20);

    /* initialize the i960RP timer 1 here */

    /* set the timer countdown */

    *trr1 = 33 * BSP_Configuration.microseconds_per_tick;

    *tcr1 = 33 * BSP_Configuration.microseconds_per_tick;

    *ipnd &= ~(1<<13);

    *imsk |= (1 << 13);

    Ttimer_val = 0;

    *tmr1 = BUS_CLOCK_1 | TMR_AUTO_RELOAD | TMR_ENABLE;

}

rtems_isr timerisr(

  rtems_vector_number vector

)

{

  /* enable_tracing(); */

  Ttimer_val++;

  i960_clear_intr( 13 );

}

#define AVG_OVERHEAD      4 /* It typically takes 5.5 microseconds */

                             /* (11 countdowns) to start/stop the timer. */

#define LEAST_VALID       5 /* Don't trust a value lower than this */

int Read_timer()

{

  volatile unsigned int *tcr1 = (unsigned int *) TCR1_ADDR;

  volatile unsigned int *trr1 = (unsigned int *) TRR1_ADDR;

  rtems_unsigned32 remaining, total;

  /* this routine is supposed to count in 1/2 uSec units */

  /* pretty funny when using a 33MHz clock for the counter */

  remaining =  *tcr1;

  remaining =  *trr1 - remaining;

  total = (2 * ((Ttimer_val * *trr1) + remaining)) / 33;

/*

  putnum(remaining);

  console_sps_putc(':');

  putnum(total);

*/

  if ( Timer_driver_Find_average_overhead == 1 )

    return total;          /* in one-half microsecond units */

  else {

    if ( total < LEAST_VALID )

      return 0;            /* below timer resolution */

    return (total-AVG_OVERHEAD) >> 1;

  }

}

rtems_status_code Empty_function( void )

{

  return RTEMS_SUCCESSFUL;

}

void Set_find_average_overhead(

  rtems_boolean find_flag

)

{

  Timer_driver_Find_average_overhead = find_flag;

}