LoRaWANTimer.h

/**
 / _____)             _              | |
( (____  _____ ____ _| |_ _____  ____| |__
 \____ \| ___ |    (_   _) ___ |/ ___)  _ \
 _____) ) ____| | | || |_| ____( (___| | | |
(______/|_____)_|_|_| \__)_____)\____)_| |_|
    (C)2013 Semtech
 
Description: Timer objects and scheduling management
 
License: Revised BSD License, see LICENSE.TXT file include in the project
 
Maintainer: Miguel Luis and Gregory Cristian
 
 
Copyright (c) 2017, Arm Limited and affiliates.
 
SPDX-License-Identifier: BSD-3-Clause
*/
 
#ifndef MBED_LORAWAN_SYS_TIMER_H__
#define MBED_LORAWAN_SYS_TIMER_H__
 
#include <stdint.h>
#include "events/EventQueue.h"
 
#include "lorawan_data_structures.h"
 
class LoRaWANTimeHandler {
public:
    LoRaWANTimeHandler();
    ~LoRaWANTimeHandler();
 
    /** Activates the timer subsystem.
     *
     * Embeds EventQueue object to timer subsystem which is subsequently
     * used to extract timer information.
     *
     * @param [in] queue  Handle to EventQueue object
     */
    void activate_timer_subsystem(events::EventQueue *queue);
 
    /** Read the current time.
     *
     * @return time The current time.
     */
    lorawan_time_t get_current_time(void);
 
    /** Return the time elapsed since a fixed moment in time.
     *
     * @param [in] saved_time    The fixed moment in time.
     * @return     time          The elapsed time.
     */
    lorawan_time_t get_elapsed_time(lorawan_time_t saved_time);
 
    /** Initializes the timer object.
     *
     * @remark The TimerSetValue function must be called before starting the timer.
     *         This function initializes the time-stamp and reloads the value at 0.
     *
     * @param [in] obj          The structure containing the timer object parameters.
     * @param [in] callback     The function callback called at the end of the timeout.
     */
    void init(timer_event_t &obj, mbed::Callback<void()> callback);
 
    /** Starts and adds the timer object to the list of timer events.
     *
     * @param [in] obj     The structure containing the timer object parameters.
     * @param [in] timeout The new timeout value.
     */
    void start(timer_event_t &obj, const uint32_t timeout);
 
    /** Stops and removes the timer object from the list of timer events.
     *
     * @param [in] obj The structure containing the timer object parameters.
     */
    void stop(timer_event_t &obj);
 
    /** Clear timer state so it is not inadvertently canceled. This function
     * must be called by the callback registered in init.
     *
     * @param [in] obj The structure containing the timer object parameters.
     */
    void clear(timer_event_t &obj);
 
private:
    events::EventQueue *_queue;
};
 
#endif // MBED_LORAWAN_SYS_TIMER_H__