mbed-os/drivers/VirtualWatchdog.h

121 lines
3.4 KiB
C++

/*
* Copyright (c) 2019 Arm Limited and affiliates.
* SPDX-License-Identifier: Apache-2.0
*
* 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 MBED_VIRTUAL_WATCHDOG_H
#define MBED_VIRTUAL_WATCHDOG_H
#ifdef DEVICE_WATCHDOG
#include <cstdio>
#include "platform/mbed_error.h"
#include "platform/mbed_critical.h"
#include "platform/mbed_power_mgmt.h"
#include "platform/mbed_assert.h"
namespace mbed {
/** \addtogroup drivers */
/** A system timer that will reset the system in the case of system failures or
* malfunctions.
*
* Example:
* @code
*
* Example:
* @code
*
* VirtualWatchdog virtual_watchdog(300,"Software Watchdog");
* virtual_watchdog.start();
*
* while (true) {
* virtual_watchdog.kick();
*
* // Application code
* }
* @endcode
* @ingroup platform
*/
class VirtualWatchdog {
public:
/** Constructor configured with timeout and name for this software watchdog instance.
*
*/
VirtualWatchdog(uint32_t timeout = 1, const char *const str = NULL);
~VirtualWatchdog();
public:
/** Start an independent watchdog timer with specified parameters.
*
* Assert for multiple calls of start.
*/
void start();
/** This stops the watchdog timer.
*
* Calling this function disables any running
* watchdog timers if the platform supports them.
*
* Assert without calling start.
*/
void stop();
/** This function refreshes the watchdog timer.
*
* Call this function periodically before the watchdog times out.
* Otherwise, the system resets.
*
* If the watchdog timer is not running, this function does nothing.
*/
void kick();
/** Periodic callback method (runs by periodic call from ticker) used this API interface
* to go through all the registered user/threads of watchdog.
*
* @param elapsed_ms Elapsed milliseconds
*
* Otherwise, the system resets.
*/
static void process(uint32_t elapsed_ms);
protected :
/** Use add_to_list to store the registered user in the list.
* This API is only used to call from start.
*/
void add_to_list();
/** Use remove_from_list to remove the entry from the list.
* This API is only used to call from stop.
*
*/
void remove_from_list();
private:
uint32_t _max_timeout; //_max_timeout initialized via constructor while creating instance of this class
const char *_name; //To store the details of user
uint32_t _current_count; //this parameter is used to reset everytime threads/user calls kick
bool _is_initialized; //To control start and stop functionality
static bool _is_hw_watchdog_running; // track we are the first owner of watchdog
static VirtualWatchdog *_first; //List to store the user/threads who called start
VirtualWatchdog *_next;
};
} // namespace mbed
#endif // DEVICE_WATCHDOG
#endif // MBED_VIRTUAL_WATCHDOG_H