linuxptp/tsproc.c

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/**
* @file tsproc.c
* @note Copyright (C) 2015 Miroslav Lichvar <mlichvar@redhat.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 <stdlib.h>
#include <inttypes.h>
#include "tsproc.h"
#include "filter.h"
#include "print.h"
struct tsproc {
/* Current ratio between remote and local clock frequency */
double clock_rate_ratio;
/* Latest down measurement */
tmv_t t1;
tmv_t t2;
/* Latest up measurement */
tmv_t t3;
tmv_t t4;
/* Current filtered delay */
tmv_t filtered_delay;
/* Delay filter */
struct filter *delay_filter;
};
struct tsproc *tsproc_create(enum filter_type delay_filter, int filter_length)
{
struct tsproc *tsp;
tsp = calloc(1, sizeof(*tsp));
if (!tsp)
return NULL;
tsp->delay_filter = filter_create(delay_filter, filter_length);
if (!tsp->delay_filter) {
free(tsp);
return NULL;
}
tsp->clock_rate_ratio = 1.0;
return tsp;
}
void tsproc_destroy(struct tsproc *tsp)
{
filter_destroy(tsp->delay_filter);
free(tsp);
}
void tsproc_down_ts(struct tsproc *tsp, tmv_t remote_ts, tmv_t local_ts)
{
tsp->t1 = remote_ts;
tsp->t2 = local_ts;
}
void tsproc_up_ts(struct tsproc *tsp, tmv_t local_ts, tmv_t remote_ts)
{
tsp->t3 = local_ts;
tsp->t4 = remote_ts;
}
void tsproc_set_clock_rate_ratio(struct tsproc *tsp, double clock_rate_ratio)
{
tsp->clock_rate_ratio = clock_rate_ratio;
}
void tsproc_set_delay(struct tsproc *tsp, tmv_t delay)
{
tsp->filtered_delay = delay;
}
tmv_t get_raw_delay(struct tsproc *tsp)
{
tmv_t t23, t41, delay;
/* delay = ((t2 - t3) * rr + (t4 - t1)) / 2 */
t23 = tmv_sub(tsp->t2, tsp->t3);
if (tsp->clock_rate_ratio != 1.0)
t23 = dbl_tmv(tmv_dbl(t23) * tsp->clock_rate_ratio);
t41 = tmv_sub(tsp->t4, tsp->t1);
delay = tmv_div(tmv_add(t23, t41), 2);
if (delay < 0) {
pr_debug("negative delay %10" PRId64, delay);
pr_debug("delay = (t2 - t3) * rr + (t4 - t1)");
pr_debug("t2 - t3 = %+10" PRId64, t23);
pr_debug("t4 - t1 = %+10" PRId64, t41);
pr_debug("rr = %.9f", tsp->clock_rate_ratio);
}
return delay;
}
int tsproc_update_delay(struct tsproc *tsp, tmv_t *delay)
{
tmv_t raw_delay;
if (tmv_is_zero(tsp->t1) || tmv_is_zero(tsp->t2) ||
tmv_is_zero(tsp->t3) || tmv_is_zero(tsp->t4))
return -1;
raw_delay = get_raw_delay(tsp);
tsp->filtered_delay = filter_sample(tsp->delay_filter, raw_delay);
pr_debug("delay filtered %10" PRId64 " raw %10" PRId64,
tsp->filtered_delay, raw_delay);
if (delay)
*delay = tsp->filtered_delay;
return 0;
}
int tsproc_update_offset(struct tsproc *tsp, tmv_t *offset)
{
tmv_t delay;
if (tmv_is_zero(tsp->t1) || tmv_is_zero(tsp->t2) ||
tmv_is_zero(tsp->t3) || tmv_is_zero(tsp->t4))
return -1;
delay = tsp->filtered_delay;
/* offset = t2 - t1 - delay */
*offset = tmv_sub(tmv_sub(tsp->t2, tsp->t1), delay);
return 0;
}
void tsproc_reset(struct tsproc *tsp, int full)
{
tsp->t1 = tmv_zero();
tsp->t2 = tmv_zero();
tsp->t3 = tmv_zero();
tsp->t4 = tmv_zero();
if (full) {
tsp->clock_rate_ratio = 1.0;
filter_reset(tsp->delay_filter);
}
}