/**
  ******************************************************************************
  * @file    cpu_utils.c
  * @author  MCD Application Team
  * @brief   Utilities for CPU Load calculation
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2014 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

/********************** NOTES **********************************************
To use this module, the following steps should be followed :

1- in the _OS_Config.h file (ex. FreeRTOSConfig.h) enable the following macros :
      - #define configUSE_IDLE_HOOK        1
      - #define configUSE_TICK_HOOK        1

2- in the _OS_Config.h define the following macros :
      - #define traceTASK_SWITCHED_IN()  extern void StartIdleMonitor(void); \
                                         StartIdleMonitor()
      - #define traceTASK_SWITCHED_OUT() extern void EndIdleMonitor(void); \
                                         EndIdleMonitor()
*******************************************************************************/


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

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private variables ---------------------------------------------------------*/

xTaskHandle    xIdleHandle = NULL;
__IO uint32_t  osCPU_Usage = 0;
uint32_t       osCPU_IdleStartTime = 0;
uint32_t       osCPU_IdleSpentTime = 0;
uint32_t       osCPU_TotalIdleTime = 0;

/* Private functions ---------------------------------------------------------*/
/**
  * @brief  Application Idle Hook
  * @param  None
  * @retval None
  */
void vApplicationIdleHook(void)
{
  if( xIdleHandle == NULL )
  {
    /* Store the handle to the idle task. */
    xIdleHandle = xTaskGetCurrentTaskHandle();
  }
}

/**
  * @brief  Application Idle Hook
  * @param  None
  * @retval None
  */
void vApplicationTickHook (void)
{
  static int tick = 0;

  if(tick ++ > CALCULATION_PERIOD)
  {
    tick = 0;

    if(osCPU_TotalIdleTime > 1000)
    {
      osCPU_TotalIdleTime = 1000;
    }
    osCPU_Usage = (100 - (osCPU_TotalIdleTime * 100) / CALCULATION_PERIOD);
    osCPU_TotalIdleTime = 0;
  }
}

/**
  * @brief  Start Idle monitor
  * @param  None
  * @retval None
  */
void StartIdleMonitor (void)
{
  if( xTaskGetCurrentTaskHandle() == xIdleHandle )
  {
    osCPU_IdleStartTime = xTaskGetTickCountFromISR();
  }
}

/**
  * @brief  Stop Idle monitor
  * @param  None
  * @retval None
  */
void EndIdleMonitor (void)
{
  if( xTaskGetCurrentTaskHandle() == xIdleHandle )
  {
    /* Store the handle to the idle task. */
    osCPU_IdleSpentTime = xTaskGetTickCountFromISR() - osCPU_IdleStartTime;
    osCPU_TotalIdleTime += osCPU_IdleSpentTime;
  }
}

/**
  * @brief  Stop Idle monitor
  * @param  None
  * @retval None
  */
uint16_t osGetCPUUsage (void)
{
  return (uint16_t)osCPU_Usage;
}