wlvncc/include/ntp.h

60 lines
1.8 KiB
C

/*
* Copyright (c) 2023 Andri Yngvason
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#pragma once
#include <stdint.h>
#include <stdbool.h>
#define NTP_SAMPLE_PERIOD 1000000 // µs
#define NTP_MIN_SAMPLE_COUNT 3
#define NTP_SAMPLE_SIZE 16
struct aml_ticker;
struct ntp_client;
typedef void (*ntp_client_ping_fn)(struct ntp_client*, uint32_t t0, uint32_t t1,
uint32_t t2, uint32_t t3);
struct ntp_sample {
int32_t theta;
uint32_t delta;
};
struct ntp_client {
struct ntp_sample samples[NTP_SAMPLE_SIZE];
int sample_index;
int sample_count;
struct aml_ticker* ping_ticker;
ntp_client_ping_fn send_ping;
void* userdata;
};
int ntp_client_init(struct ntp_client*, ntp_client_ping_fn send_ping,
void* userdata);
void ntp_client_deinit(struct ntp_client*);
void ntp_client_process_pong(struct ntp_client*, uint32_t t0, uint32_t t1,
uint32_t t2, uint32_t t3);
bool ntp_client_get_best_sample(const struct ntp_client* self,
struct ntp_sample* sample);
bool ntp_client_translate_server_time(const struct ntp_client* self,
uint32_t* dst, const uint32_t t);