2020年12月17日 | STM32F7xx —— 看门狗

看门狗：指定时间内不喂狗，就重启系统。

最简单的看门狗设计（喂狗就是指定时间内给寄存器写一个固定值）

// 初始化独立看门狗

// prer:分频数:0~7(只有低 3 位有效!)

// rlr:自动重装载值,0~0XFFF.

// 分频因子=4*2^prer.但最大值只能是 256!

// rlr:重装载寄存器值:低 11 位有效.

// 时间计算(大概):Tout=((4*2^prer)*rlr)/32 (ms).

static IWDG_HandleTypeDef iwdg_handle;

void WatchdogInit(void)

{

  iwdg_handle.Instance = IWDG;

  iwdg_handle.Init.Prescaler = 5;

  iwdg_handle.Init.Reload = 250;

  iwdg_handle.Init.Window = IWDG_WINDOW_DISABLE; // 关闭窗口功能

  HAL_IWDG_Init(&iwdg_handle);

  os_watchdog_lock = xSemaphoreCreateMutex();

}

void WatchdogFeed(void)

{

  HAL_IWDG_Refresh(&iwdg_handle);

}

FreeRTOS看门狗设计（系统看门狗+任务看门狗）（其他操作系统也可以用这种思路）

任务看门狗：监控每个任务的活动状态，如果任务卡死，会导致系统重启。核心思想是使用计数，计数减为0后说明任务卡死。

TaskHandle_t os_watchdog_handle;

// 互斥信号量

static SemaphoreHandle_t os_watchdog_lock;

#define WATCHDOG_LOCK()    xSemaphoreTake(os_watchdog_lock, 100);

#define WATCHDOG_UNLOCK()  xSemaphoreGive(os_watchdog_lock)

#define WATCHDOG_CHECK_INTERVAL  100  // 100ms喂一次狗

#define WATCHDOG_POOL_SIZE       (OS_PRIO_MAX + OS_PRIO_MAX - 1) // 任务池 2倍的任务-1

typedef struct

{

  TaskHandle_t handle; // 任务句柄

  const char *name;    // 任务看门狗名称

  uint16_t timeout;    // 任务看门狗超时

  uint16_t time;       // 任务看门狗计数

  uint8_t suspended;   // 任务看门狗暂停

} watchdog_t;

static watchdog_t watchdogs[WATCHDOG_POOL_SIZE];

static void task_watchdog(void *params)

{

  int i;

  while(1)

  {

    WatchdogFeed();

    for(i = 0; i < WATCHDOG_POOL_SIZE; ++i)

    {

      if(0 == watchdogs[i].handle)

      {

        continue;

      }

      if(!watchdogs[i].suspended && watchdogs[i].time)

      {

        --(watchdogs[i].time);

      }

      if(!watchdogs[i].suspended && (0 == watchdogs[i].time))

      {

        printf("!!!!!!!!!!!!!!!! Watchdog %s timeout !!!!!!!!!!!!!!!!n", watchdogs[i].name);

        while(1);  // reset

      }

    }

    vTaskDelay(WATCHDOG_CHECK_INTERVAL);

  }

}

// 初始化独立看门狗

// prer:分频数:0~7(只有低 3 位有效!)

// rlr:自动重装载值,0~0XFFF.

// 分频因子=4*2^prer.但最大值只能是 256!

// rlr:重装载寄存器值:低 11 位有效.

// 时间计算(大概):Tout=((4*2^prer)*rlr)/32 (ms).

static IWDG_HandleTypeDef iwdg_handle;

void WatchdogInit(void)

{

  iwdg_handle.Instance = IWDG;

  iwdg_handle.Init.Prescaler = 5;

  iwdg_handle.Init.Reload = 250;

  iwdg_handle.Init.Window = IWDG_WINDOW_DISABLE; // 关闭窗口功能

  HAL_IWDG_Init(&iwdg_handle);

  os_watchdog_lock = xSemaphoreCreateMutex();

  xTaskCreate((TaskFunction_t)task_watchdog,

              (const char*   )"task_watchdog",

              (uint16_t      )OS_WATCHDOG_STK_SIZE,

              (void*         )NULL,

              (UBaseType_t   )OS_PRIO_WATCHDOG,

              (TaskHandle_t* )&os_watchdog_handle);

}

void WatchdogFeed(void)

{

  HAL_IWDG_Refresh(&iwdg_handle);

}

//===============================================================================================================

// 任务看门狗注册

void WatchdogRegister(const char *name, uint16_t timeout)

{

  int i;

  TaskHandle_t handle = xTaskGetCurrentTaskHandle();

  WATCHDOG_LOCK();

  for(i = 0; i < WATCHDOG_POOL_SIZE; ++i)

  {

    if (handle == watchdogs[i].handle)

    {

      WATCHDOG_UNLOCK();

      return;

    }

  }

  for(i = 0; i < WATCHDOG_POOL_SIZE; ++i)

  {

    if (0 == watchdogs[i].handle)

    {

      watchdogs[i].handle = handle;

      watchdogs[i].name = name;

      watchdogs[i].timeout = (timeout + WATCHDOG_CHECK_INTERVAL - 1) / WATCHDOG_CHECK_INTERVAL;

      watchdogs[i].time = watchdogs[i].timeout;

      watchdogs[i].suspended = 0;

      break;

    }

  }

  WATCHDOG_UNLOCK();

}

// 任务看门狗喂狗

void WatchdogKick(void)

{

  int i;

  TaskHandle_t handle = xTaskGetCurrentTaskHandle();

  for(i = 0; i < WATCHDOG_POOL_SIZE; ++i)

  {

    if (handle == watchdogs[i].handle)

    {

      WATCHDOG_LOCK();

      watchdogs[i].time = watchdogs[i].timeout;

      WATCHDOG_UNLOCK();

      break;

    }

  }

}

// 任务看门狗暂停

void WatchdogSuspend(void)

{

  int i;

  TaskHandle_t handle = xTaskGetCurrentTaskHandle();

  for(i = 0; i < WATCHDOG_POOL_SIZE; ++i)

  {

    if (handle == watchdogs[i].handle)

    {

      WATCHDOG_LOCK();

      watchdogs[i].suspended = 1;

      WATCHDOG_UNLOCK();

      break;

    }

  }

}

// 任务看门狗恢复

void WatchdogResume(void)

{

  int i;

  TaskHandle_t handle = xTaskGetCurrentTaskHandle();

  for(i = 0; i < WATCHDOG_POOL_SIZE; ++i)

  {

    if (handle == watchdogs[i].handle)

    {

      WATCHDOG_LOCK();

      watchdogs[i].time = watchdogs[i].timeout;

      watchdogs[i].suspended = 0;

      WATCHDOG_UNLOCK();

      break;

    }

  }

}