timecounter.h

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/*
 * Copyright (c) 2015 embedded brains GmbH.  All rights reserved.
 *
 *  embedded brains GmbH
 *  Dornierstr. 4
 *  82178 Puchheim
 *  Germany
 *  <rtems@embedded-brains.de>
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rtems.org/license/LICENSE.
 */

#ifndef _RTEMS_TIMECOUNTER_H
#define _RTEMS_TIMECOUNTER_H

#include <rtems/score/timecounter.h>
#include <rtems/score/basedefs.h>

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#define RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER 100

RTEMS_INLINE_ROUTINE void rtems_timecounter_install(
  struct timecounter *tc
)
{
  _Timecounter_Install( tc );
}

RTEMS_INLINE_ROUTINE void rtems_timecounter_tick(void)
{
  _Timecounter_Tick();
}

typedef struct {
  struct timecounter tc;
  uint64_t scaler;
  uint32_t real_interval;
  uint32_t binary_interval;
} rtems_timecounter_simple;

typedef void rtems_timecounter_simple_at_tick(
  rtems_timecounter_simple *tc
);

typedef uint32_t rtems_timecounter_simple_get(
  rtems_timecounter_simple *tc
);

typedef bool rtems_timecounter_simple_is_pending(
  rtems_timecounter_simple *tc
);

void rtems_timecounter_simple_install(
  rtems_timecounter_simple *tc,
  uint32_t                  counter_frequency_in_hz,
  uint32_t                  counter_ticks_per_clock_tick,
  timecounter_get_t        *get_timecount
);

RTEMS_INLINE_ROUTINE uint32_t rtems_timecounter_simple_scale(
  const rtems_timecounter_simple *tc,
  uint32_t value
)
{
  return (uint32_t) ( ( value * tc->scaler ) >> 32 );
}

RTEMS_INLINE_ROUTINE void rtems_timecounter_simple_downcounter_tick(
  rtems_timecounter_simple         *tc,
  rtems_timecounter_simple_get      get,
  rtems_timecounter_simple_at_tick  at_tick
)
{
  ISR_lock_Context lock_context;
  uint32_t current;

  _Timecounter_Acquire( &lock_context );

  ( *at_tick )( tc );

  current = rtems_timecounter_simple_scale(
    tc,
    tc->real_interval - ( *get )( tc )
  );

  _Timecounter_Tick_simple( tc->binary_interval, current, &lock_context );
}

RTEMS_INLINE_ROUTINE void rtems_timecounter_simple_upcounter_tick(
  rtems_timecounter_simple         *tc,
  rtems_timecounter_simple_get      get,
  rtems_timecounter_simple_at_tick  at_tick
)
{
  ISR_lock_Context lock_context;
  uint32_t current;

  _Timecounter_Acquire( &lock_context );

  ( *at_tick )( tc );

  current = rtems_timecounter_simple_scale( tc, ( *get )( tc ) );

  _Timecounter_Tick_simple( tc->binary_interval, current, &lock_context );
}

RTEMS_INLINE_ROUTINE uint32_t rtems_timecounter_simple_downcounter_get(
  struct timecounter                  *tc_base,
  rtems_timecounter_simple_get         get,
  rtems_timecounter_simple_is_pending  is_pending
)
{
  rtems_timecounter_simple *tc;
  uint32_t counter;
  uint32_t interval;

  tc = (rtems_timecounter_simple *) tc_base;
  counter = ( *get )( tc );
  interval = tc->real_interval;

  if ( ( *is_pending )( tc ) ) {
    counter = ( *get )( tc );
    interval *= 2;
  }

  return rtems_timecounter_simple_scale( tc, interval - counter );
}

RTEMS_INLINE_ROUTINE uint32_t rtems_timecounter_simple_upcounter_get(
  struct timecounter                  *tc_base,
  rtems_timecounter_simple_get         get,
  rtems_timecounter_simple_is_pending  is_pending
)
{
  rtems_timecounter_simple *tc;
  uint32_t counter;
  uint32_t interval;

  tc = (rtems_timecounter_simple *) tc_base;
  counter = ( *get )( tc );
  interval = 0;

  if ( ( *is_pending )( tc ) ) {
    counter = ( *get )( tc );
    interval = tc->real_interval;
  }

  return rtems_timecounter_simple_scale( tc, interval + counter );
}

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* _RTEMS_TIMECOUNTER_H */