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/**
* @file sysoff.h
* @brief Implements the system offset estimation method.
* @note Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdint.h>
#include "missing.h"
enum {
SYSOFF_RUN_TIME_MISSING = -1,
SYSOFF_PRECISE,
SYSOFF_EXTENDED,
SYSOFF_BASIC,
SYSOFF_LAST,
};
/**
* Check to see if a PTP_SYS_OFFSET ioctl is supported.
* @param fd An open file descriptor to a PHC device.
* @return One of the SYSOFF_ enumeration values.
*/
int sysoff_probe(int fd, int n_samples);
/**
* Measure the offset between a PHC and the system time.
* @param fd An open file descriptor to a PHC device.
* @param method A non-negative SYSOFF_ value returned by sysoff_probe().
* @param n_samples The number of consecutive readings to make.
* @param result The estimated offset in nanoseconds.
* @param ts The system time corresponding to the 'result'.
* @param delay The delay in reading of the clock in nanoseconds.
* @return Zero on success, negative error code otherwise.
*/
int sysoff_measure(int fd, int method, int n_samples,
int64_t *result, uint64_t *ts, int64_t *delay);
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