zephyr/lib/posix/clock.c

38 lines
808 B
C

/*
* Copyright (c) 2018 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel.h>
#include <errno.h>
#include <posix/time.h>
#include <posix/sys/types.h>
/**
* @brief Get clock time specified by clock_id.
*
* See IEEE 1003.1
*/
int clock_gettime(clockid_t clock_id, struct timespec *ts)
{
s64_t elapsed_msecs, elapsed_secs;
s64_t elapsed_nsec, elapsed_cycles;
if (clock_id != CLOCK_MONOTONIC) {
errno = EINVAL;
return -1;
}
elapsed_msecs = k_uptime_get();
elapsed_secs = elapsed_msecs / MSEC_PER_SEC;
elapsed_cycles = (s64_t) (k_cycle_get_32() %
sys_clock_hw_cycles_per_sec);
elapsed_nsec = (s64_t) ((elapsed_cycles * NSEC_PER_SEC) /
sys_clock_hw_cycles_per_sec);
ts->tv_sec = (s32_t) elapsed_secs;
ts->tv_nsec = (s32_t) elapsed_nsec;
return 0;
}