/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup RTEMSAPIClassicTimecounter
*
* @brief This source file contains the implementation of
* rtems_timecounter_simple_install().
*/
/*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/timecounter.h>
void rtems_timecounter_simple_install(
rtems_timecounter_simple *tc,
uint32_t frequency_in_hz,
uint32_t counter_ticks_per_clock_tick,
timecounter_get_t *get_timecount
)
{
uint32_t power_of_two = 1;
uint32_t mask;
uint64_t scaler;
int i;
for ( i = 0; i < 32; ++i ) {
if ( power_of_two >= counter_ticks_per_clock_tick ) {
break;
}
power_of_two *= 2;
}
mask = ( 2 * power_of_two ) - 1;
scaler = ( (uint64_t) power_of_two << 32 ) / counter_ticks_per_clock_tick;
tc->scaler = scaler;
tc->real_interval = counter_ticks_per_clock_tick;
tc->binary_interval = ( mask + 1 ) / 2;
tc->tc.tc_get_timecount = get_timecount;
tc->tc.tc_counter_mask = mask;
tc->tc.tc_frequency = (uint32_t) ( ( frequency_in_hz * scaler ) >> 32 );
tc->tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER;
_Timecounter_Install( &tc->tc );
}
