/**
  ******************************************************************************
  * @file    RCC/RCC_ClockConfig/Src/main.c
  * @author  MCD Application Team
  * @brief   This example describes how to use the RCC HAL API to configure the
  *          system clock (SYSCLK) and modify the clock settings on run time.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2016 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */

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

/** @addtogroup STM32F3xx_HAL_Examples
  * @{
  */

/** @addtogroup RCC_ClockConfig
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
__IO FlagStatus SwitchClock = RESET;

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void SystemClockHSI_Config(void);
static void SystemClockHSEbypass_Config(void);
static void SwitchSystemClock(void);
static void Error_Handler(void);

/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /* STM32F3xx HAL library initialization:
       - Configure the Flash prefetch
       - Configure the Systick to generate an interrupt each 1 msec
       - Set NVIC Group Priority to 4
       - Low Level Initialization
     */
  HAL_Init();

  /* Enable HSE oscillator and configure the PLL to reach the max system frequency (64 MHz)
     when using HSE oscillator as PLL clock source. */
  SystemClock_Config();
  
  /* Configure LED1, LED2 and LED3 */
  BSP_LED_Init(LED1);
  BSP_LED_Init(LED2);
  BSP_LED_Init(LED3);

  /* Initialize User push-button, will be used to trigger an interrupt each time it's pressed.*/
  BSP_PB_Init(BUTTON_USER, BUTTON_MODE_EXTI);

  /* Output SYSCLK  on MCO1 pin(PA.08) */
  HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_SYSCLK, RCC_MCODIV_1);

  /* Toggle some leds in an infinite loop */
  while (1)
  {
    /* check if user button has been pressed to switch clock config */
    if(SwitchClock != RESET)
    {
      SwitchSystemClock();
    }
    
    /* Toggle LED1 */
    BSP_LED_Toggle(LED1);
    HAL_Delay(100);
  }
}


/**
  * @brief  EXTI line detection callbacks.
  * @param  GPIO_Pin: Specifies the pins connected EXTI line
  * @retval None
  */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
  if (GPIO_Pin == USER_BUTTON_PIN)
  {
    SwitchClock = SET;
  }
}


/**
  * @brief  switch in system clock out of ISR context.
  * @retval None
  */
static void SwitchSystemClock(void)
{
  if (__HAL_RCC_GET_PLL_OSCSOURCE() == RCC_PLLSOURCE_HSI)
  {
    /* PLL source is HSI oscillator */
    /* Set SYSCLK frequency to 72000000 Hz, coming from the PLL which is clocked by HSE bypass */
    SystemClockHSEbypass_Config();
  }
  else if (__HAL_RCC_GET_PLL_OSCSOURCE() == RCC_PLLSOURCE_HSE)
  {
    /* PLL source is HSE bypass oscillator */
    /* Set SYSCLK frequency to 64000000 Hz, coming from the PLL which is clocked by HSI */
    SystemClockHSI_Config();
  }

  /* reset global variable */
  SwitchClock = RESET;
}

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow : 
  *            System Clock source            = PLL (HSI)
  *            SYSCLK(Hz)                     = 64000000
  *            HCLK(Hz)                       = 64000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSI Frequency(Hz)              = 8000000
  *            PREDIV                         = RCC_PREDIV_DIV2 (2)
  *            PLLMUL                         = RCC_PLL_MUL16 (16)
  *            Flash Latency(WS)              = 2
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  
  /* HSI Oscillator already ON after system reset, activate PLL with HSI as source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_NONE;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV2;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL16;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }

  /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 
     clocks dividers */
  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;  
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }
}
/**
  * @brief  Switch the PLL source from HSI to HSE bypass, and select the PLL as SYSCLK
  *         source.
  *         The system Clock is configured as follows :
  *            System Clock source            = PLL (HSE bypass)
  *            SYSCLK(Hz)                     = 72000000
  *            HCLK(Hz)                       = 72000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSE Frequency(Hz)              = 8000000
  *            HSE PREDIV                     = 1
  *            PLLMUL                         = 9
  *            Flash Latency(WS)              = 2
  * @param  None
  * @retval None
  */
static void SystemClockHSEbypass_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};

  /* -1- Select HSI as system clock source to allow modification of the PLL configuration */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }
  
  /* -2- Enable HSE bypass Oscillator, select it as PLL source and finally activate the PLL */
  RCC_OscInitStruct.OscillatorType        = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState              = RCC_HSE_BYPASS;
  RCC_OscInitStruct.PLL.PREDIV            = RCC_PREDIV_DIV1;
  
  RCC_OscInitStruct.PLL.PLLSource         = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLState          = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLMUL            = RCC_PLL_MUL9;

  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /* -3- Select the PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
  RCC_ClkInitStruct.ClockType       = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
  RCC_ClkInitStruct.SYSCLKSource    = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider   = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider  = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider  = RCC_HCLK_DIV1;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /* -4- Optional: Disable HSI Oscillator (if the HSI is no more needed by the application)*/
  RCC_OscInitStruct.OscillatorType  = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState        = RCC_HSI_OFF;
  RCC_OscInitStruct.PLL.PLLState    = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }
}

/**
  * @brief  Switch the PLL source from HSE bypass to HSI, and select the PLL as SYSCLK
  *         source.
  *         The system Clock is configured as follows :
  *            System Clock source            = PLL (HSI)
  *            SYSCLK(Hz)                     = 64000000
  *            HCLK(Hz)                       = 64000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSI Frequency(Hz)              = 8000000
  *            PREDIV                         = 2
  *            PLLMUL                         = 16
  *            Flash Latency(WS)              = 2
  * @param  None
  * @retval None
  */
static void SystemClockHSI_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};

  /* -1- Select HSE bypass as system clock source to allow modification of the PLL configuration */
  RCC_ClkInitStruct.ClockType       = RCC_CLOCKTYPE_SYSCLK;
  RCC_ClkInitStruct.SYSCLKSource    = RCC_SYSCLKSOURCE_HSE;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /* -2- Enable HSI Oscillator, select it as PLL source and finally activate the PLL */
  RCC_OscInitStruct.OscillatorType       = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState             = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue  = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState         = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource        = RCC_PLLSOURCE_HSI;
  /* PLL source is the HSI frequency divided by 2 */
  RCC_OscInitStruct.PLL.PREDIV           = RCC_PREDIV_DIV2;
  RCC_OscInitStruct.PLL.PLLMUL           = RCC_PLL_MUL16;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /* -3- Select the PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
  RCC_ClkInitStruct.ClockType       = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
  RCC_ClkInitStruct.SYSCLKSource    = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider   = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider  = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider  = RCC_HCLK_DIV1;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /* -4- Optional: Disable HSE bypass Oscillator (if the HSE bypass is no more needed by the application) */
  RCC_OscInitStruct.OscillatorType  = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState        = RCC_HSE_OFF;
  RCC_OscInitStruct.PLL.PLLState    = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }
}


/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
  /* Turn LED2 on */
  BSP_LED_On(LED2);

  while (1)
  {
  }
}
 
#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
}
#endif

/**
  * @}
  */

/**
  * @}
  */

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