nuttx/sched/clock/clock_systime_timespec.c
zhangyuan21 8512ca74b1 clock: adjust clock function to support tick
When CONFIG_SCHED_TICKLESS_TICK_ARGUMENT enabled, we can
use up_timer_gettick to get ticks for better performance.
2022-11-01 21:54:20 +08:00

135 lines
3.8 KiB
C

/****************************************************************************
* sched/clock/clock_systime_timespec.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <time.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/arch.h>
#include <nuttx/clock.h>
#include "clock/clock.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: clock_systime_timespec
*
* Description:
* Return the current value of the system timer counter as a struct
* timespec. The returned time is the elapsed time since power up.
*
* Input Parameters:
* ts - Location to return the time
*
* Returned Value:
* Current version almost always returns OK. Currently errors are
* possible with CONFIG_RTC_HIRES only.
*
* Assumptions:
*
****************************************************************************/
int clock_systime_timespec(FAR struct timespec *ts)
{
#ifdef CONFIG_RTC_HIRES
/* Do we have a high-resolution RTC that can provide us with the time? */
if (g_rtc_enabled)
{
int ret;
/* Get the hi-resolution time from the RTC. This will return the
* current time, not the time since power up.
*/
ret = up_rtc_gettime(ts);
if (ret < 0)
{
return ret;
}
/* Subtract the base time to this in order to convert this to the
* time since power up.
*/
DEBUGASSERT(ts->tv_sec >= g_basetime.tv_sec);
if (ts->tv_sec < g_basetime.tv_sec)
{
/* Negative times are not supported */
return -ENOSYS;
}
ts->tv_sec -= g_basetime.tv_sec;
if (ts->tv_nsec < g_basetime.tv_nsec)
{
/* Borrow */
if (ts->tv_sec < 1)
{
/* Negative times are not supported */
return -ENOSYS;
}
ts->tv_sec--;
ts->tv_nsec += NSEC_PER_SEC;
}
ts->tv_nsec -= g_basetime.tv_nsec;
return OK;
}
else
#endif
{
/* In tickless mode, all timing is controlled by platform-specific
* code. Let the platform timer do the work.
*/
#if defined(CONFIG_SCHED_TICKLESS_TICK_ARGUMENT)
clock_t ticks;
int ret;
ret = up_timer_gettick(&ticks);
timespec_from_tick(ts, ticks);
return ret;
#elif defined(CONFIG_SCHED_TICKLESS)
return up_timer_gettime(ts);
#else
/* 64-bit microsecond calculations should improve our accuracy
* when the clock period is in units of microseconds.
*/
timespec_from_tick(ts, clock_systime_ticks());
return OK;
#endif
}
}