

/* Includes ------------------------------------------------------------------*/
#include "stm32l0xx_hal.h"

/** @addtogroup STM32L0xx_HAL_Driver
  * @{
  */

/** @addtogroup HAL_TimeBase
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
TIM_HandleTypeDef        TimHandle;
/* Private function prototypes -----------------------------------------------*/
void TIM21_IRQHandler(void);
/* Private functions ---------------------------------------------------------*/

/**
  * @brief  This function configures the TIM21 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    clkconfig;
  uint32_t              uwTimclock;
  uint32_t              uwAPB2Prescaler;
  uint32_t              uwPrescalerValue;
  uint32_t              pFLatency;
  HAL_StatusTypeDef     status;

  /* Configure the TIM21 IRQ priority */
  HAL_NVIC_SetPriority(TIM21_IRQn, TickPriority, 0U);

  /* Enable the TIM21 global Interrupt */
  HAL_NVIC_EnableIRQ(TIM21_IRQn);

  /* Enable TIM21 clock */
  __HAL_RCC_TIM21_CLK_ENABLE();

  /* Get clock configuration */
  HAL_RCC_GetClockConfig(&clkconfig, &pFLatency);

  /* Get APB2 prescaler */
  uwAPB2Prescaler = clkconfig.APB2CLKDivider;

  /* Compute TIM21 clock */
  if (uwAPB2Prescaler == RCC_HCLK_DIV1)
  {
    uwTimclock = HAL_RCC_GetPCLK2Freq();
  }
  else
  {
    uwTimclock = 2U * HAL_RCC_GetPCLK2Freq();
  }

  /* Compute the prescaler value to have TIM21 counter clock equal to 1MHz */
  uwPrescalerValue = (uint32_t)((uwTimclock / 1000000U) - 1U);

  /* Initialize TIM21 */
  TimHandle.Instance = TIM21;

  /* Initialize TIMx peripheral as follow:
  + Period = [(TIM21CLK/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 = (1000000U / 1000U) - 1U;
  TimHandle.Init.Prescaler = uwPrescalerValue;
  TimHandle.Init.ClockDivision = 0;
  TimHandle.Init.CounterMode = TIM_COUNTERMODE_UP;
  status = HAL_TIM_Base_Init(&TimHandle);
  if (status == HAL_OK)
  {
    /* Start the TIM time Base generation in interrupt mode */
    status = HAL_TIM_Base_Start_IT(&TimHandle);
    if (status == HAL_OK)
    {
      /* Configure the SysTick IRQ priority */
      if (TickPriority < (1UL << __NVIC_PRIO_BITS))
      {
        /* Configure the TIM IRQ priority */
        HAL_NVIC_SetPriority(TIM21_IRQn, TickPriority, 0U);
        uwTickPrio = TickPriority;
      }
      else
      {
        status = HAL_ERROR;
      }
    }
  }

  /* Return function status */
  return status;
}

/**
  * @brief  Suspend Tick increment.
  * @note   Disable the tick increment by disabling TIM21 update interrupt.
  * @param  None
  * @retval None
  */
void HAL_SuspendTick(void)
{
  /* Disable TIM21 update interrupt */
  __HAL_TIM_DISABLE_IT(&TimHandle, TIM_IT_UPDATE);
}

/**
  * @brief  Resume Tick increment.
  * @note   Enable the tick increment by enabling TIM21 update interrupt.
  * @param  None
  * @retval None
  */
void HAL_ResumeTick(void)
{
  /* Enable TIM21 update interrupt */
  __HAL_TIM_ENABLE_IT(&TimHandle, TIM_IT_UPDATE);
}

/**
  * @brief  Period elapsed callback in non blocking mode
  * @note   This function is called  when TIM21 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 TIM21_IRQHandler(void)
{
  HAL_TIM_IRQHandler(&TimHandle);
}

/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
