timecounter.h

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/* SPDX-License-Identifier: BSD-2-Clause */
 
/*
 * Copyright (c) 2015 embedded brains GmbH & Co. KG
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
 
#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
 
static inline void rtems_timecounter_install(
  struct timecounter *tc
)
{
  _Timecounter_Install( tc );
}
 
static inline 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
);
 
static inline uint32_t rtems_timecounter_simple_scale(
  const rtems_timecounter_simple *tc,
  uint32_t value
)
{
  return (uint32_t) ( ( value * tc->scaler ) >> 32 );
}
 
static inline 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 );
}
 
static inline 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 );
}
 
static inline 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 );
}
 
static inline 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 */