OVMS3-idf/components/lwip/include/apps/sntp/sntp.h

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// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef __SNTP_H__
#define __SNTP_H__
#ifdef __cplusplus
extern "C" {
#endif
/*
* The time update takes place in the sntp_sync_time() function.
* The user has the ability to redefine this function in order
* to re-define its functionality. This function has two time update modes,
* which can be set via the sntp_set_sync_mode() function.
* Two modes are available:
* - the first is an immediate update when receiving time from the sntp server,
* - the second is a smooth time update (if the time error is no more than 35 minutes,
* and an immediate update if the error is more than 35 minutes).
*
* To receive notification of time synchronization,
* you can use the callback function or get the synchronization status
* via the sntp_get_sync_status() function.
*
* To determine the time synchronization time on the device, you can use:
* 1) sntp_set_time_sync_notification_cb() function to set the callback function,
* which is convenient to use to receive notification of the update time.
* 2) sntp_get_sync_status() function for getting time synchronization status.
* After the time synchronization is completed, the status will be
* SNTP_SYNC_STATUS_COMPLETED, after, it will be reseted to SNTP_SYNC_STATUS_RESET
* to wait for the next sync cycle.
*/
/// SNTP time update mode
typedef enum {
SNTP_SYNC_MODE_IMMED, /*!< Update system time immediately when receiving a response from the SNTP server. */
SNTP_SYNC_MODE_SMOOTH, /*!< Smooth time updating. Time error is gradually reduced using adjtime function. If the difference between SNTP response time and system time is large (more than 35 minutes) then update immediately. */
} sntp_sync_mode_t;
/// SNTP sync status
typedef enum {
SNTP_SYNC_STATUS_RESET, // Reset status.
SNTP_SYNC_STATUS_COMPLETED, // Time is synchronized.
SNTP_SYNC_STATUS_IN_PROGRESS, // Smooth time sync in progress.
} sntp_sync_status_t;
/**
* @brief SNTP callback function for notifying about time sync event
*
* @param tv Time received from SNTP server.
*/
typedef void (*sntp_sync_time_cb_t) (struct timeval *tv);
/**
* @brief This function updates the system time.
*
* This is a weak-linked function. It is possible to replace all SNTP update functionality
* by placing a sntp_sync_time() function in the app firmware source.
* If the default implementation is used, calling sntp_set_sync_mode() allows
* the time synchronization mode to be changed to instant or smooth.
* If a callback function is registered via sntp_set_time_sync_notification_cb(),
* it will be called following time synchronization.
*
* @param tv Time received from SNTP server.
*/
void sntp_sync_time(struct timeval *tv);
/**
* @brief Set the sync mode
*
* Allowable two mode: SNTP_SYNC_MODE_IMMED and SNTP_SYNC_MODE_SMOOTH.
* @param sync_mode Sync mode.
*/
void sntp_set_sync_mode(sntp_sync_mode_t sync_mode);
/**
* @brief Get set sync mode
*
* @return SNTP_SYNC_MODE_IMMED: Update time immediately.
* SNTP_SYNC_MODE_SMOOTH: Smooth time updating.
*/
sntp_sync_mode_t sntp_get_sync_mode(void);
/**
* @brief Get status of time sync
*
* After the update is completed, the status will be returned as SNTP_SYNC_STATUS_COMPLETED.
* After that, the status will be reset to SNTP_SYNC_STATUS_RESET.
* If the update operation is not completed yet, the status will be SNTP_SYNC_STATUS_RESET.
* If a smooth mode was chosen and the synchronization is still continuing (adjtime works), then it will be SNTP_SYNC_STATUS_IN_PROGRESS.
*
* @return SNTP_SYNC_STATUS_RESET: Reset status.
* SNTP_SYNC_STATUS_COMPLETED: Time is synchronized.
* SNTP_SYNC_STATUS_IN_PROGRESS: Smooth time sync in progress.
*/
sntp_sync_status_t sntp_get_sync_status(void);
/**
* @brief Set status of time sync
*
* @param sync_status status of time sync (see sntp_sync_status_t)
*/
void sntp_set_sync_status(sntp_sync_status_t sync_status);
/**
* @brief Set a callback function for time synchronization notification
*
* @param callback a callback function
*/
void sntp_set_time_sync_notification_cb(sntp_sync_time_cb_t callback);
/**
* @brief Set the sync interval of SNTP operation
*
* Note: SNTPv4 RFC 4330 enforces a minimum sync interval of 15 seconds.
* This sync interval will be used in the next attempt update time throught SNTP.
* To apply the new sync interval call the sntp_restart() function,
* otherwise, it will be applied after the last interval expired.
*
* @param interval_ms The sync interval in ms. It cannot be lower than 15 seconds, otherwise 15 seconds will be set.
*/
void sntp_set_sync_interval(uint32_t interval_ms);
/**
* @brief Get the sync interval of SNTP operation
*
* @return the sync interval
*/
uint32_t sntp_get_sync_interval(void);
/**
* @brief Restart SNTP
*
* @return True - Restart
* False - SNTP was not initialized yet
*/
bool sntp_restart(void);
#ifdef __cplusplus
}
#endif
#endif // __SNTP_H__