107 lines
3.1 KiB
C
107 lines
3.1 KiB
C
/* Copyright (c) 2011-2015, The Linux Foundation. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials provided
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* with the distribution.
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* * Neither the name of The Linux Foundatoin, nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
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* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <errno.h>
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#include <sys/time.h>
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#include <sys/ioctl.h>
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#include <linux/types.h>
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#include <linux/pps.h>
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#ifndef _TIMEPPS_H
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#define _TIMEPPS_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* time of assert event */
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typedef struct timespec pps_info;
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/* represents pps source */
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typedef int pps_handle;
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/* Open the PPS source */
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static __inline int pps_create(int source, pps_handle *handle)
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{
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int ret;
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struct pps_kparams dummy;
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if (!handle)
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{
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errno = EINVAL;
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return -1;
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}
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/* check if current device is valid pps */
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ret = ioctl(source, PPS_GETPARAMS, &dummy);
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if (ret)
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{
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errno = EOPNOTSUPP;
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return -1;
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}
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*handle = source;
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return 0;
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}
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/* close the pps source */
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static __inline int pps_destroy(pps_handle handle)
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{
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return close(handle);
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}
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/*reads timestamp from pps device*/
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static __inline int pps_fetch(pps_handle handle, const int tsformat,
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pps_info *ppsinfobuf,
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const struct timespec *timeout)
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{
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struct pps_fdata fdata;
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int ret;
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if (tsformat != PPS_TSFMT_TSPEC)
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{
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errno = EINVAL;
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return -1;
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}
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if (timeout)
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{
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fdata.timeout.sec = timeout->tv_sec;
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fdata.timeout.nsec = timeout->tv_nsec;
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fdata.timeout.flags = ~PPS_TIME_INVALID;
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}
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else
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{
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fdata.timeout.flags = PPS_TIME_INVALID;
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}
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ret = ioctl(handle, PPS_FETCH, &fdata);
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ppsinfobuf->tv_sec = fdata.info.assert_tu.sec;
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ppsinfobuf->tv_nsec = fdata.info.assert_tu.nsec;
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return ret;
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}
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#ifdef __cplusplus
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}
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#endif
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#endif
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