android_device_samsung_msm8.../gps/gnsspps/gnsspps.c
2019-02-11 23:56:38 +03:00

194 lines
5.4 KiB
C
Executable file

/* Copyright (c) 2011-2015, The Linux Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of The Linux Foundatoin, nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <log_util.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <pthread.h>
#include <timepps.h>
#include <linux/types.h>
//DRsync kernel timestamp
static struct timespec drsyncKernelTs = {0,0};
//DRsync userspace timestamp
static struct timespec drsyncUserTs = {0,0};
//flag to stop fetching timestamp
static int isActive = 0;
static pps_handle handle;
static pthread_mutex_t ts_lock;
/* checks the PPS source and opens it */
int check_device(char *path, pps_handle *handle)
{
int ret;
/* Try to find the source by using the supplied "path" name */
ret = open(path, O_RDWR);
if (ret < 0)
{
LOC_LOGV("%s:%d unable to open device %s", __func__, __LINE__, path);
return ret;
}
/* Open the PPS source */
ret = pps_create(ret, handle);
if (ret < 0)
{
LOC_LOGV( "%s:%d cannot create a PPS source from device %s", __func__, __LINE__, path);
return -1;
}
return 0;
}
/* fetches the timestamp from the PPS source */
int read_pps(pps_handle *handle)
{
struct timespec timeout;
pps_info infobuf;
int ret;
// 3sec timeout
timeout.tv_sec = 3;
timeout.tv_nsec = 0;
ret = pps_fetch(*handle, PPS_TSFMT_TSPEC, &infobuf,&timeout);
if (ret < 0 && ret !=-EINTR)
{
LOC_LOGV("%s:%d pps_fetch() error %d", __func__, __LINE__, ret);
return -1;
}
pthread_mutex_lock(&ts_lock);
drsyncKernelTs.tv_sec = infobuf.tv_sec;
drsyncKernelTs.tv_nsec = infobuf.tv_nsec;
ret = clock_gettime(CLOCK_BOOTTIME,&drsyncUserTs);
pthread_mutex_unlock(&ts_lock);
if(ret != 0)
{
LOC_LOGV("%s:%d clock_gettime() error",__func__,__LINE__);
}
return 0;
}
#ifdef __cplusplus
extern "C" {
#endif
/* infinitely calls read_pps() */
void *thread_handle(void *input)
{
int ret;
if(input != NULL)
{
LOC_LOGV("%s:%d Thread Input is present", __func__, __LINE__);
}
while(isActive)
{
ret = read_pps(&handle);
if (ret == -1 && errno != ETIMEDOUT )
{
LOC_LOGV("%s:%d Could not fetch PPS source", __func__, __LINE__);
}
}
return NULL;
}
/* opens the device and fetches from PPS source */
int initPPS(char *devname)
{
int ret,pid;
pthread_t thread;
isActive = 1;
ret = check_device(devname, &handle);
if (ret < 0)
{
LOC_LOGV("%s:%d Could not find PPS source", __func__, __LINE__);
return 0;
}
pthread_mutex_init(&ts_lock,NULL);
pid = pthread_create(&thread,NULL,&thread_handle,NULL);
if(pid != 0)
{
LOC_LOGV("%s:%d Could not create thread in InitPPS", __func__, __LINE__);
return 0;
}
return 1;
}
/* stops fetching and closes the device */
void deInitPPS()
{
pthread_mutex_lock(&ts_lock);
isActive = 0;
pthread_mutex_unlock(&ts_lock);
pthread_mutex_destroy(&ts_lock);
pps_destroy(handle);
}
/* retrieves DRsync kernel timestamp,DRsync userspace timestamp
and updates current timestamp */
/* Returns:
* 1. @Param out DRsync kernel timestamp
* 2. @Param out DRsync userspace timestamp
* 3. @Param out current timestamp
*/
int getPPS(struct timespec *fineKernelTs ,struct timespec *currentTs,
struct timespec *fineUserTs)
{
int ret;
pthread_mutex_lock(&ts_lock);
fineKernelTs->tv_sec = drsyncKernelTs.tv_sec;
fineKernelTs->tv_nsec = drsyncKernelTs.tv_nsec;
fineUserTs->tv_sec = drsyncUserTs.tv_sec;
fineUserTs->tv_nsec = drsyncUserTs.tv_nsec;
ret = clock_gettime(CLOCK_BOOTTIME,currentTs);
pthread_mutex_unlock(&ts_lock);
if(ret != 0)
{
LOC_LOGV("%s:%d clock_gettime() error",__func__,__LINE__);
return 0;
}
return 1;
}
#ifdef __cplusplus
}
#endif