/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    PWR/PWR_LPSLEEP/Src/main.c
  * @author  MCD Application Team
  * @brief   This sample code shows how to use STM32WLxx PWR HAL API to enter
  *          and exit the Low Power Sleep mode.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2020 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.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define LED_TOGGLE_DELAY         100
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */
static uint32_t TimingDelay;

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Decrease(void);

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */
  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  /* USER CODE BEGIN 2 */

  /* Configure LED2 and LED3 */
  BSP_LED_Init(LED2);
  BSP_LED_Init(LED3);

  /* User push-button (B1) (line 0) will be used to wakeup the system from STOP mode */
  BSP_PB_Init(BUTTON_SW1, BUTTON_MODE_EXTI);

  /* Enable Flash power down mode during Sleep mode     */
  /* (uncomment this line if power consumption figures  */
  /*  must be measured with Flash still on in Low Power */
  /*  Sleep mode)                                       */
  HAL_PWREx_EnableFlashPowerDown(PWR_FLASHPD_LPSLEEP);

  /* Reset all RCC Sleep and Stop modes register to */
  /* improve power consumption                      */
  RCC->AHB1SMENR  = 0x0;
  RCC->AHB2SMENR  = 0x0;
  RCC->AHB3SMENR  = 0x0;
  
  RCC->APB1SMENR1 = 0x0;
  RCC->APB1SMENR2 = 0x0;
  RCC->APB2SMENR  = 0x0;
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
    /* Insert 5 seconds delay */
    HAL_Delay(5000);  

    /* Reduce the System clock to below 2 MHz */
    SystemClock_Decrease();

    /* Suspend Tick increment to prevent wakeup by Systick interrupt.         */
    /* Otherwise the Systick interrupt will wake up the device within 1ms     */
    /* (HAL time base).                                                       */
    HAL_SuspendTick();

    /* De-init LED2 */
    BSP_LED_DeInit(LED2);

    /* Enter Sleep Mode, wake up is done once User push-button (B1) is pressed */
    HAL_PWR_EnterSLEEPMode(PWR_LOWPOWERREGULATOR_ON, PWR_SLEEPENTRY_WFI);

    /* ... Low-power SLEEP mode ... */

    /* System is Low Power Run mode when exiting Low Power Sleep mode,
       disable low power run mode and reset the clock to initialization configuration */ 
    HAL_PWREx_DisableLowPowerRunMode();

    /* Configure the system clock for the RUN mode */
    SystemClock_Config();

    /* Re-init LED2 to toggle during Run mode */
    BSP_LED_Init(LED2);

    /* Resume Tick interrupt if disabled prior to Low Power Sleep mode entry */
    HAL_ResumeTick();
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
  RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_8;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;
  RCC_OscInitStruct.PLL.PLLM = RCC_PLLM_DIV4;
  RCC_OscInitStruct.PLL.PLLN = 24;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Configure the SYSCLKSource, HCLK, PCLK1 and PCLK2 clocks dividers
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK3|RCC_CLOCKTYPE_HCLK
                              |RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1
                              |RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.AHBCLK3Divider = RCC_SYSCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

/* USER CODE BEGIN 4 */
/**
  * @brief  System Clock Speed decrease
  *         The system Clock source is shifted from PLL to MSI
  *         while at the same time, MSI range is set to RCC_MSIRANGE_1
  *         to go down to 200 KHz     
  * @param  None
  * @retval None
  */
void SystemClock_Decrease(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  /** Configure the main internal regulator output voltage 
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_MSI);

  /* Disable PLL to reduce power consumption since MSI is used from that point */
  /* Change MSI frequency */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
  RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_1;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_OFF;
  if(HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /* Select MSI as system clock source */
  /* Note: Keep AHB and APB prescaler settings from previous structure initialization */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI; 
  if(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }
}

/**
  * @brief SYSTICK callback
  * @param None
  * @retval None
  */
void HAL_SYSTICK_Callback(void)
{
  if (TimingDelay != 0)
  {
    TimingDelay--;
  }
  else
  {
    /* Toggle LED2 */
    BSP_LED_Toggle(LED2);
    TimingDelay = LED_TOGGLE_DELAY;
  }
}

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  
  /* Suspend tick */
  HAL_SuspendTick();

  /* Turn LED3 on */
  BSP_LED_On(LED3);
  while(1)
  {
  }
  /* USER CODE END Error_Handler_Debug */
}

#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 CODE BEGIN 6 */
  /* 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)
  {
  }
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
