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/*
chronyd/chronyc - Programs for keeping computer clocks accurate.
**********************************************************************
* Copyright (C) Miroslav Lichvar 2013, 2017, 2023
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* 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.
*
**********************************************************************
=======================================================================
PTP hardware clock (PHC) refclock driver.
*/
#include "config.h"
#include "refclock.h"
#ifdef FEAT_PHC
#include "sysincl.h"
#include <sys/sysmacros.h>
#include "array.h"
#include "refclock.h"
#include "hwclock.h"
#include "local.h"
#include "logging.h"
#include "memory.h"
#include "util.h"
#include "sched.h"
#include "sys_linux.h"
struct phc_instance {
int fd;
int dev_index;
int mode;
int nocrossts;
int extpps;
int pin;
int channel;
struct timespec last_extts;
HCL_Instance clock;
};
/* Array of RCL_Instance with enabled extpps */
static ARR_Instance extts_phcs = NULL;
static void read_ext_pulse(int sockfd, int event, void *anything);
static int phc_initialise(RCL_Instance instance)
{
const char *options[] = {"nocrossts", "extpps", "pin", "channel", "clear", NULL};
struct phc_instance *phc;
int phc_fd, rising_edge;
struct stat st;
char *path, *s;
RCL_CheckDriverOptions(instance, options);
path = RCL_GetDriverParameter(instance);
phc_fd = SYS_Linux_OpenPHC(path, 0);
if (phc_fd < 0)
LOG_FATAL("Could not open PHC");
phc = MallocNew(struct phc_instance);
phc->fd = phc_fd;
if (fstat(phc_fd, &st) < 0 || !S_ISCHR(st.st_mode))
LOG_FATAL("Could not get PHC index");
phc->dev_index = minor(st.st_rdev);
phc->mode = 0;
phc->nocrossts = RCL_GetDriverOption(instance, "nocrossts") ? 1 : 0;
phc->extpps = RCL_GetDriverOption(instance, "extpps") ? 1 : 0;
UTI_ZeroTimespec(&phc->last_extts);
phc->clock = HCL_CreateInstance(0, 16, UTI_Log2ToDouble(RCL_GetDriverPoll(instance)),
RCL_GetPrecision(instance));
if (phc->extpps) {
s = RCL_GetDriverOption(instance, "pin");
phc->pin = s ? atoi(s) : 0;
s = RCL_GetDriverOption(instance, "channel");
phc->channel = s ? atoi(s) : 0;
rising_edge = RCL_GetDriverOption(instance, "clear") ? 0 : 1;
if (!SYS_Linux_SetPHCExtTimestamping(phc->fd, phc->pin, phc->channel,
rising_edge, !rising_edge, 1))
LOG_FATAL("Could not enable external PHC timestamping");
SCH_AddFileHandler(phc->fd, SCH_FILE_INPUT, read_ext_pulse, instance);
if (!extts_phcs)
extts_phcs = ARR_CreateInstance(sizeof (RCL_Instance));
ARR_AppendElement(extts_phcs, &instance);
} else {
phc->pin = phc->channel = 0;
}
RCL_SetDriverData(instance, phc);
return 1;
}
static void phc_finalise(RCL_Instance instance)
{
struct phc_instance *phc;
unsigned int i;
phc = (struct phc_instance *)RCL_GetDriverData(instance);
if (phc->extpps) {
SCH_RemoveFileHandler(phc->fd);
SYS_Linux_SetPHCExtTimestamping(phc->fd, phc->pin, phc->channel, 0, 0, 0);
for (i = 0; i < ARR_GetSize(extts_phcs); i++) {
if ((*(RCL_Instance *)ARR_GetElement(extts_phcs, i)) == instance)
ARR_RemoveElement(extts_phcs, i--);
}
if (ARR_GetSize(extts_phcs) == 0) {
ARR_DestroyInstance(extts_phcs);
extts_phcs = NULL;
}
}
HCL_DestroyInstance(phc->clock);
close(phc->fd);
Free(phc);
}
static void process_ext_pulse(RCL_Instance instance, struct timespec *phc_ts)
{
struct phc_instance *phc;
struct timespec local_ts;
double local_err;
phc = RCL_GetDriverData(instance);
if (UTI_CompareTimespecs(&phc->last_extts, phc_ts) == 0) {
DEBUG_LOG("Ignoring duplicated PHC timestamp");
return;
}
phc->last_extts = *phc_ts;
if (!HCL_CookTime(phc->clock, phc_ts, &local_ts, &local_err))
return;
RCL_AddCookedPulse(instance, &local_ts, 1.0e-9 * local_ts.tv_nsec, local_err,
UTI_DiffTimespecsToDouble(phc_ts, &local_ts));
}
static void read_ext_pulse(int fd, int event, void *anything)
{
RCL_Instance instance;
struct phc_instance *phc1, *phc2;
struct timespec phc_ts;
unsigned int i;
int channel;
if (!SYS_Linux_ReadPHCExtTimestamp(fd, &phc_ts, &channel))
return;
instance = anything;
phc1 = RCL_GetDriverData(instance);
/* The Linux kernel (as of 6.2) has one shared queue of timestamps for all
descriptors of the same PHC. Search for all refclocks that expect
the timestamp. */
for (i = 0; i < ARR_GetSize(extts_phcs); i++) {
instance = *(RCL_Instance *)ARR_GetElement(extts_phcs, i);
phc2 = RCL_GetDriverData(instance);
if (!phc2->extpps || phc2->dev_index != phc1->dev_index || phc2->channel != channel)
continue;
process_ext_pulse(instance, &phc_ts);
}
}
#define PHC_READINGS 25
static int phc_poll(RCL_Instance instance)
{
struct timespec phc_ts, sys_ts, local_ts, readings[PHC_READINGS][3];
struct phc_instance *phc;
double phc_err, local_err;
int n_readings;
phc = (struct phc_instance *)RCL_GetDriverData(instance);
n_readings = SYS_Linux_GetPHCReadings(phc->fd, phc->nocrossts, &phc->mode,
PHC_READINGS, readings);
if (n_readings < 1)
return 0;
if (!HCL_ProcessReadings(phc->clock, n_readings, readings, &phc_ts, &sys_ts, &phc_err))
return 0;
LCL_CookTime(&sys_ts, &local_ts, &local_err);
HCL_AccumulateSample(phc->clock, &phc_ts, &local_ts, phc_err + local_err);
if (phc->extpps)
return 0;
DEBUG_LOG("PHC offset: %+.9f err: %.9f",
UTI_DiffTimespecsToDouble(&phc_ts, &sys_ts), phc_err);
return RCL_AddSample(instance, &sys_ts, &phc_ts, LEAP_Normal);
}
RefclockDriver RCL_PHC_driver = {
phc_initialise,
phc_finalise,
phc_poll
};
#else
RefclockDriver RCL_PHC_driver = { NULL, NULL, NULL };
#endif
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