text: /**
    ******************************************************************************
    * @file    stm32f4xx_hal_timebase_tim.c 
    * @author  MCD Application Team
    * @version V1.0.2
    * @date    06-May-2016
    * @brief   HAL time base based on the hardware TIM.
    *    
    *          This file override the native HAL time base functions (defined as weak)
    *          the TIM time base:
    *           + Intializes the TIM peripheral generate a Period elapsed Event each 1ms
    *           + HAL_IncTick is called inside HAL_TIM_PeriodElapsedCallback ie each 1ms
    * 
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; COPYRIGHT(c) 2016 STMicroelectronics</center></h2>
    *
    * Redistribution and use in source and binary forms, with or without modification,
    * are permitted provided that the following conditions are met:
    *   1. Redistributions of source code must retain the above copyright notice,
    *      this list of conditions and the following disclaimer.
    *   2. Redistributions in binary form must reproduce the above copyright notice,
    *      this list of conditions and the following disclaimer in the documentation
    *      and/or other materials provided with the distribution.
    *   3. Neither the name of STMicroelectronics nor the names of its contributors
    *      may be used to endorse or promote products derived from this software
    *      without specific prior written permission.
    *
    * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
    * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    *
    ******************************************************************************
    */
  
  /* Includes ------------------------------------------------------------------*/
  #include "stm32f4xx_hal.h"
  
  /** @addtogroup STM32F4xx_HAL_Driver
    * @{
    */
  
  /** @addtogroup HAL_TimeBase
    * @{
    */ 
  
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  /* Private macro -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  TIM_HandleTypeDef        TimHandle;
  /* Private function prototypes -----------------------------------------------*/
  void TIM5_IRQHandler(void);
  /* Private functions ---------------------------------------------------------*/
  
  /**
    * @brief  This function configures the TIM5 as a time base source. 
    *         The time source is configured  to have 1ms time base with a dedicated 
    *         Tick interrupt priority. 
    * @note   This function is called  automatically at the beginning of program after
    *         reset by HAL_Init() or at any time when clock is configured, by HAL_RCC_ClockConfig(). 
    * @param  TickPriority: Tick interrupt priority.
    * @retval HAL status
    */
  HAL_StatusTypeDef HAL_InitTick (uint32_t TickPriority)
  {
    RCC_ClkInitTypeDef sClokConfig;
    uint32_t uwTimclock, uwAPB1Prescaler = 0;
    uint32_t uwPrescalerValue = 0;
    uint32_t pFLatency;
    
    /*##-1- Enable peripherals and GPIO Clocks #################################*/
    /* Enable TIM5 clock */
    __HAL_RCC_TIM5_CLK_ENABLE();
  
    /*##-2- Configure the NVIC for TIMx ########################################*/
    /* Set the TIM5 priority */
    HAL_NVIC_SetPriority(TIM5_IRQn, TICK_INT_PRIORITY, 0);
    
    /* Enable the TIM5 global Interrupt */
    HAL_NVIC_EnableIRQ(TIM5_IRQn);
  
    /* Configure the TIM5 IRQ priority */
    HAL_NVIC_SetPriority(TIM5_IRQn, TickPriority ,0); 
    
    /* Get clock configuration */
    HAL_RCC_GetClockConfig(&sClokConfig, &pFLatency);
    
    /* Get APB1 prescaler */
    uwAPB1Prescaler = sClokConfig.APB1CLKDivider;
    
    /* Compute TIM5 clock */
    if (uwAPB1Prescaler == 0) 
    {
      uwTimclock = HAL_RCC_GetPCLK1Freq();
    }
    else
    {
      uwTimclock = 2*HAL_RCC_GetPCLK1Freq();
    }
  
    /* Compute the prescaler value to have TIM5 counter clock equal to 1MHz */
    uwPrescalerValue = (uint32_t) ((uwTimclock / 1000000) - 1);
    
    /* Initialize TIM5 */
    TimHandle.Instance = TIM5;
      
    /* Initialize TIMx peripheral as follow:
         + Period = [(TIM5CLK/1000) - 1]. to have a (1/1000) s time base.
         + Prescaler = (uwTimclock/1000000 - 1) to have a 1MHz counter clock.
         + ClockDivision = 0
         + Counter direction = Up
    */
    TimHandle.Init.Period = (1000000 / 1000) - 1;
    TimHandle.Init.Prescaler = uwPrescalerValue;
    TimHandle.Init.ClockDivision = 0;
    TimHandle.Init.CounterMode = TIM_COUNTERMODE_UP;
    if(HAL_TIM_Base_Init(&TimHandle) == HAL_OK)
    {
      /* Start the TIM time Base generation in interrupt mode */
      return HAL_TIM_Base_Start_IT(&TimHandle);
    }
  
    /* Return function status */
    return HAL_OK;
  }
  
  /**
    * @brief  Suspend Tick increment.
    * @note   Disable the tick increment by disabling TIM5 update interrupt.
    * @param  None
    * @retval None
    */
  void HAL_SuspendTick(void)
  {
    /* Disable TIM5 update Interrupt */
    __HAL_TIM_DISABLE_IT(&TimHandle, TIM_IT_UPDATE);
  }
  
  /**
    * @brief  Resume Tick increment.
    * @note   Enable the tick increment by Enabling TIM5 update interrupt.
    * @param  None
    * @retval None
    */
  void HAL_ResumeTick(void)
  {
    /* Enable TIM5 Update interrupt */
    __HAL_TIM_ENABLE_IT(&TimHandle, TIM_IT_UPDATE);
  }
  
  /**
    * @brief  Period elapsed callback in non blocking mode
    * @note   This function is called  when TIM5 interrupt took place, inside
    * HAL_TIM_IRQHandler(). It makes a direct call to HAL_IncTick() to increment
    * a global variable "uwTick" used as application time base.
    * @param  htim : TIM handle
    * @retval None
    */
  void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
  {
    HAL_IncTick();
  }
  
  /**
    * @brief  This function handles TIM interrupt request.
    * @param  None
    * @retval None
    */
  void TIM5_IRQHandler(void)
  {
    HAL_TIM_IRQHandler(&TimHandle);
  }
  
  /**
    * @}
    */ 
  
  /**
    * @}
    */ 
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  