incubator-nuttx/sched/clock/clock_timekeeping.c

296 lines
8.0 KiB
C

/****************************************************************************
* sched/clock/clock_timekeeping.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>
#ifdef CONFIG_CLOCK_TIMEKEEPING
#include <sys/time.h>
#include <stdint.h>
#include <time.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include "clock/clock.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define NTP_MAX_ADJUST 500
/****************************************************************************
* Private Data
****************************************************************************/
static struct timespec g_clock_wall_time;
static uint64_t g_clock_last_counter;
static uint64_t g_clock_mask;
static long g_clock_adjust;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: clock_get_current_time
****************************************************************************/
static int clock_get_current_time(FAR struct timespec *ts,
FAR struct timespec *base)
{
irqstate_t flags;
uint64_t counter;
uint64_t offset;
uint64_t nsec;
time_t sec;
int ret;
flags = enter_critical_section();
ret = up_timer_getcounter(&counter);
if (ret < 0)
{
goto errout_in_critical_section;
}
offset = (counter - g_clock_last_counter) & g_clock_mask;
nsec = offset * NSEC_PER_TICK;
sec = nsec / NSEC_PER_SEC;
nsec -= sec * NSEC_PER_SEC;
nsec += base->tv_nsec;
if (nsec >= NSEC_PER_SEC)
{
nsec -= NSEC_PER_SEC;
sec += 1;
}
ts->tv_nsec = nsec;
ts->tv_sec = base->tv_sec + sec;
errout_in_critical_section:
leave_critical_section(flags);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: clock_timekeeping_get_wall_time
****************************************************************************/
int clock_timekeeping_get_wall_time(FAR struct timespec *ts)
{
return clock_get_current_time(ts, &g_clock_wall_time);
}
/****************************************************************************
* Name: clock_timekeeping_set_wall_time
****************************************************************************/
int clock_timekeeping_set_wall_time(FAR struct timespec *ts)
{
irqstate_t flags;
uint64_t counter;
int ret;
flags = enter_critical_section();
ret = up_timer_getcounter(&counter);
if (ret < 0)
{
goto errout_in_critical_section;
}
memcpy(&g_clock_wall_time, ts, sizeof(struct timespec));
g_clock_adjust = 0;
g_clock_last_counter = counter;
errout_in_critical_section:
leave_critical_section(flags);
return ret;
}
/****************************************************************************
* Name: adjtime
*
* Description:
* The adjtime() function gradually adjusts the system clock (as returned
* by gettimeofday(2)). The amount of time by which the clock is to be
* adjusted is specified in the structure pointed to by delta.
*
* This structure has the following form:
*
* struct timeval
* {
* time_t tv_sec; (seconds)
* suseconds_t tv_usec; (microseconds)
* };
*
* If the adjustment in delta is positive, then the system clock is
* speeded up by some small percentage (i.e., by adding a small amount of
* time to the clock value in each second) until the adjustment has been
* completed. If the adjustment in delta is negative, then the clock is
* slowed down in a similar fashion.
*
* If a clock adjustment from an earlier adjtime() call is already in
* progress at the time of a later adjtime() call, and delta is not NULL
* for the later call, then the earlier adjustment is stopped, but any
* already completed part of that adjustment is not undone.
*
* If olddelta is not NULL, then the buffer that it points to is used to
* return the amount of time remaining from any previous adjustment that
* has not yet been completed.
*
* NOTE: This is not a POSIX interface but derives from 4.3BSD, System V.
* It is also supported for Linux compatibility.
*
****************************************************************************/
int adjtime(FAR const struct timeval *delta, FAR struct timeval *olddelta)
{
irqstate_t flags;
long adjust_usec;
if (!delta)
{
set_errno(EINVAL);
return -1;
}
flags = enter_critical_section();
adjust_usec = delta->tv_sec * USEC_PER_SEC + delta->tv_usec;
if (olddelta)
{
olddelta->tv_usec = g_clock_adjust;
}
g_clock_adjust = adjust_usec;
leave_critical_section(flags);
return OK;
}
/****************************************************************************
* Name: clock_update_wall_time
****************************************************************************/
void clock_update_wall_time(void)
{
irqstate_t flags;
uint64_t counter;
uint64_t offset;
int64_t nsec;
time_t sec;
int ret;
flags = enter_critical_section();
ret = up_timer_getcounter(&counter);
if (ret < 0)
{
goto errout_in_critical_section;
}
offset = (counter - g_clock_last_counter) & g_clock_mask;
if (offset == 0)
{
goto errout_in_critical_section;
}
nsec = offset * NSEC_PER_TICK;
sec = nsec / NSEC_PER_SEC;
nsec -= sec * NSEC_PER_SEC;
nsec += g_clock_wall_time.tv_nsec;
if (nsec >= NSEC_PER_SEC)
{
nsec -= NSEC_PER_SEC;
sec += 1;
}
if (g_clock_adjust != 0 && sec > 0)
{
long adjust = NTP_MAX_ADJUST * (long)sec;
if (g_clock_adjust < adjust && g_clock_adjust > -adjust)
{
adjust = g_clock_adjust;
}
nsec += adjust * NSEC_PER_USEC;
while (nsec < 0)
{
nsec += NSEC_PER_SEC;
sec -= 1;
}
while (nsec >= NSEC_PER_SEC)
{
nsec -= NSEC_PER_SEC;
sec += 1;
}
}
g_clock_wall_time.tv_sec += sec;
g_clock_wall_time.tv_nsec = (long)nsec;
g_clock_last_counter = counter;
errout_in_critical_section:
leave_critical_section(flags);
}
/****************************************************************************
* Name: clock_inittimekeeping
****************************************************************************/
void clock_inittimekeeping(FAR const struct timespec *tp)
{
up_timer_getmask(&g_clock_mask);
if (tp)
{
memcpy(&g_clock_wall_time, tp, sizeof(struct timespec));
}
else
{
clock_basetime(&g_clock_wall_time);
}
up_timer_getcounter(&g_clock_last_counter);
}
#endif /* CONFIG_CLOCK_TIMEKEEPING */