incubator-nuttx/sched/clock/clock_systimer.c

137 lines
4.2 KiB
C

/****************************************************************************
* sched/clock/clock_systimer.c
*
* Copyright (C) 2011, 2014-2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include <nuttx/clock.h>
#include "clock/clock.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* See nuttx/clock.h */
#undef clock_systimer
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: clock_systimer
*
* Description:
* Return the current value of the 32/64-bit system timer counter
*
* Parameters:
* None
*
* Return Value:
* The current value of the system timer counter
*
* Assumptions:
*
****************************************************************************/
systime_t clock_systimer(void)
{
#ifdef CONFIG_SCHED_TICKLESS
# ifdef CONFIG_SYSTEM_TIME64
struct timespec ts;
/* Get the time from the platform specific hardware */
#ifndef CONFIG_CLOCK_TIMEKEEPING
(void)up_timer_gettime(&ts);
#else
(void)clock_timekeeping_get_monotonic_time(&ts);
#endif
/* Convert to a 64-bit value in microseconds, then in clock tick units */
return USEC2TICK(1000000 * (uint64_t)ts.tv_sec + (uint64_t)ts.tv_nsec / 1000);
# else /* CONFIG_SYSTEM_TIME64 */
struct timespec ts;
uint64_t tmp;
/* Get the time from the platform specific hardware */
#ifndef CONFIG_CLOCK_TIMEKEEPING
(void)up_timer_gettime(&ts);
#else
(void)clock_timekeeping_get_monotonic_time(&ts);
#endif
/* Convert to a 64- then a 32-bit value */
tmp = USEC2TICK(1000000 * (uint64_t)ts.tv_sec + (uint64_t)ts.tv_nsec / 1000);
return (systime_t)(tmp & 0x00000000ffffffff);
# endif /* CONFIG_SYSTEM_TIME64 */
#else /* CONFIG_SCHED_TICKLESS */
# ifdef CONFIG_SYSTEM_TIME64
irqstate_t flags;
systime_t sample;
/* 64-bit accesses are not atomic on most architectures. */
flags = enter_critical_section();
sample = g_system_timer;
leave_critical_section(flags);
return sample;
# else /* CONFIG_SYSTEM_TIME64 */
/* Return the current system time */
return g_system_timer;
# endif /* CONFIG_SYSTEM_TIME64 */
#endif /* CONFIG_SCHED_TICKLESS */
}