/**
  ******************************************************************************
  * @file    I2C/I2C_WakeUpFromStop/Src/main.c 
  * @author  MCD Application Team
  * @brief   This sample code shows how to use STM32F0xx I2C HAL API to transmit 
  *          and receive a data buffer with a communication process in stop mode
  *          based on IT transfer. 
  *          The communication is done using 2 Boards.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2016 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.
  *
  ******************************************************************************
  */

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

/** @addtogroup STM32F0xx_HAL_Examples
  * @{
  */

/** @addtogroup I2C_WakeUpFromStop
  * @{
  */ 

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Uncomment this line to use the board as master, if not it is used as slave */
//#define MASTER_BOARD
#define I2C_ADDRESS        0xCA

/* I2C TIMING Register define when I2C clock source is HSI*/
/* I2C TIMING is calculated in case of the I2C Clock source is the HSI = 8 MHz */
/* This example use TIMING to 0x00201D2C to reach 100Khz speed (Rise time = 50ns, Fall time = 10ns) */
#define I2C_TIMING      0x00201D2C

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* I2C handler declaration */
/* I2C handler declared in "stm32f072b_discovery.c" file */
extern I2C_HandleTypeDef I2cHandle;


/* Buffer used for transmission */
uint8_t aTxBuffer[] = " ****I2C_TwoBoards communication wake up from stop mode based on IT****  ****I2C_TwoBoards communication wake up from stop mode based on IT****  ****I2C_TwoBoards communication wake up from stop mode based on IT**** ";

/* Buffer used for reception */
uint8_t aRxBuffer[RXBUFFERSIZE];

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static uint16_t Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength);
static void Error_Handler(void);

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

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /* STM32F0xx HAL library initialization:
       - Configure the Flash prefetch
       - Systick timer is configured by default as source of time base, but user 
         can eventually implement his proper time base source (a general purpose 
         timer for example or other time source), keeping in mind that Time base 
         duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and 
         handled in milliseconds basis.
       - Low Level Initialization
     */
  HAL_Init();
  
  /* Configure the system clock to 48 MHz */
  SystemClock_Config();
  
  /* Configure LED_GREEN, LED_RED and LED_BLUE*/
  BSP_LED_Init(LED_GREEN);
  BSP_LED_Init(LED_RED);
  BSP_LED_Init(LED_BLUE);

  /*##-1- Configure the I2C peripheral ######################################*/
  I2cHandle.Instance             = I2Cx;
  I2cHandle.Init.Timing          = I2C_TIMING;
  I2cHandle.Init.OwnAddress1     = I2C_ADDRESS;
  I2cHandle.Init.AddressingMode  = I2C_ADDRESSINGMODE_7BIT;
  I2cHandle.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  I2cHandle.Init.OwnAddress2     = 0xFF;
  I2cHandle.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  I2cHandle.Init.NoStretchMode   = I2C_NOSTRETCH_DISABLE;

  if(HAL_I2C_Init(&I2cHandle) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /* Enable the Analog I2C Filter */
  HAL_I2CEx_ConfigAnalogFilter(&I2cHandle,I2C_ANALOGFILTER_ENABLE);

#ifdef MASTER_BOARD
  
  /* Configure User push-button */
  BSP_PB_Init(BUTTON_USER,BUTTON_MODE_GPIO);

  /* Wait for User push-button press before starting the Communication */
  while (BSP_PB_GetState(BUTTON_USER) != GPIO_PIN_RESET)
  {
  }

  /* Wait for User push-button release before starting the Communication */
  while (BSP_PB_GetState(BUTTON_USER) != GPIO_PIN_SET)
  {
  }

  /* The board sends the message and expects to receive it back */

  /*##-2- Start the transmission process #####################################*/
  /* While the I2C in reception process, user can transmit data through 
     "aTxBuffer" buffer */
  do
  {
    if(HAL_I2C_Master_Transmit_IT(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t*)aTxBuffer, TXBUFFERSIZE)!= HAL_OK)
    {
      /* Error_Handler() function is called when error occurs. */
      Error_Handler();
    }

    /*##-3- Wait for the end of the transfer #################################*/  
    /*  Before starting a new communication transfer, you need to check the current   
        state of the peripheral; if it’s busy you need to wait for the end of current
        transfer before starting a new one.
        For simplicity reasons, this example is just waiting till the end of the 
        transfer, but application may perform other tasks while transfer operation
        is ongoing. */  
    while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
    {
    } 

    /* When Acknowledge failure occurs (Slave don't acknowledge it's address)
       Master restarts communication */
  }
  while(HAL_I2C_GetError(&I2cHandle) == HAL_I2C_ERROR_AF);

  /* Wait for User push-button press before starting the Communication */
  while (BSP_PB_GetState(BUTTON_USER) != GPIO_PIN_RESET)
  {
  }

  /* Wait for User push-button release before starting the Communication */
  while (BSP_PB_GetState(BUTTON_USER) != GPIO_PIN_SET)
  {
  }

  /*##-4- Put I2C peripheral in reception process ###########################*/
  do
  {
    if(HAL_I2C_Master_Receive_IT(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t *)aRxBuffer, RXBUFFERSIZE) != HAL_OK)
    {
      /* Error_Handler() function is called when error occurs. */
      Error_Handler();
    }

    /*##-5- Wait for the end of the transfer #################################*/  
    /*  Before starting a new communication transfer, you need to check the current   
        state of the peripheral; if it’s busy you need to wait for the end of current
        transfer before starting a new one.
        For simplicity reasons, this example is just waiting till the end of the 
        transfer, but application may perform other tasks while transfer operation
        is ongoing. */  
    while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
    {
    } 

    /* When Acknowledge failure occurs (Slave don't acknowledge it's address)
       Master restarts communication */
  }
  while(HAL_I2C_GetError(&I2cHandle) == HAL_I2C_ERROR_AF);

#else
  /*##-2- Enable I2C peripheral in wake up from stop mode ###################*/
  HAL_I2CEx_EnableWakeUp(&I2cHandle);

  /*##-3- Put I2C peripheral in reception process ###########################*/
  if(HAL_I2C_Slave_Receive_IT(&I2cHandle, (uint8_t *)aRxBuffer, RXBUFFERSIZE) != HAL_OK)
  {
    /* Transfer error in reception process */
    Error_Handler();
  }
 
  /* enter stop mode */
  /* Turn LED_BLUE on */
  BSP_LED_On(LED_BLUE);

  /* Configure the WakeUp clock source */

  /* Enable Power Control clock */
  __HAL_RCC_PWR_CLK_ENABLE();

  HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);

  /* ... STOP mode ... */

  /* Wake Up from Stop mode */
  /* Turn LED_BLUE off */
  BSP_LED_Off(LED_BLUE);

  /*##-4- Wait for the end of the transfer ###################################*/
  /*  Before starting a new communication transfer, you need to check the current
      state of the peripheral; if it’s busy you need to wait for the end of current
      transfer before starting a new one.
      For simplicity reasons, this example is just waiting till the end of the
      transfer, but application may perform other tasks while transfer operation
      is ongoing. */
  while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
  {
  } 

  /*##-5- Start the transmission process #####################################*/  
  /* While the I2C in reception process, user can transmit data through 
     "aTxBuffer" buffer */
  if(HAL_I2C_Slave_Transmit_IT(&I2cHandle, (uint8_t*)aTxBuffer, TXBUFFERSIZE)!= HAL_OK)
  {
    /* Transfer error in transmission process */
    Error_Handler();
  }

  /* enter stop mode */
  /* Turn LED_BLUE on */
  BSP_LED_On(LED_BLUE);
  HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);

  /* ... STOP mode ... */

  /* Disable Power Control clock */
  __HAL_RCC_PWR_CLK_DISABLE();

  /* Wake Up from Stop mode */
  /* Turn LED_BLUE off */
  BSP_LED_Off(LED_BLUE);
#endif /* MASTER_BOARD */

  /*##-6- Wait for the end of the transfer ###################################*/
  /*  Before starting a new communication transfer, you need to check the current
      state of the peripheral; if it’s busy you need to wait for the end of current
      transfer before starting a new one.
      For simplicity reasons, this example is just waiting till the end of the
      transfer, but application may perform other tasks while transfer operation
      is ongoing. */
  while (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY)
  {
  } 

  /*##-7- Compare the sent and received buffers ##############################*/
  if(Buffercmp((uint8_t*)aTxBuffer,(uint8_t*)aRxBuffer,RXBUFFERSIZE))
  {
    /* Processing Error */
    Error_Handler();
  }

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

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow : 
  *            System Clock source            = PLL (HSI48)
  *            SYSCLK(Hz)                     = 48000000
  *            HCLK(Hz)                       = 48000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 1
  *            HSI Frequency(Hz)              = 48000000
  *            PREDIV                         = 2
  *            PLLMUL                         = 2
  *            Flash Latency(WS)              = 1
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  
  /* Select HSI48 Oscillator as PLL source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI48;
  RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI48;
  RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV2;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL2;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }

  /* Select PLL as system clock source and configure the HCLK and PCLK1 clocks dividers */
  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1);
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }
}

/**
  * @brief  Tx Transfer completed callback.
  * @param  I2cHandle: I2C handle. 
  * @note   This example shows a simple way to report end of IT Tx transfer, and 
  *         you can add your own implementation. 
  * @retval None
  */
#ifdef MASTER_BOARD
void HAL_I2C_MasterTxCpltCallback(I2C_HandleTypeDef *I2cHandle)
{
  /* Toggle LED_GREEN: Transfer in transmission process is correct */
  BSP_LED_Toggle(LED_GREEN);
}
#else
void HAL_I2C_SlaveTxCpltCallback(I2C_HandleTypeDef *I2cHandle)
{
  /* Restore config: clock, GPIO... */
  SystemClock_Config();

  /* Restore GPIO configuration */
  BSP_LED_Init(LED_GREEN);
  BSP_LED_Init(LED_BLUE);

  /* Wake Up from Stop Mode */
  /* Turn LED_BLUE off */
  BSP_LED_Off(LED_BLUE);
  /* Turn off LED_GREEN: Transfer in transmission process is correct */
  BSP_LED_Off(LED_GREEN);
}
#endif /* MASTER_BOARD */

/**
  * @brief  Rx Transfer completed callback.
  * @param  I2cHandle: I2C handle
  * @note   This example shows a simple way to report end of IT Rx transfer, and 
  *         you can add your own implementation.
  * @retval None
  */
#ifdef MASTER_BOARD
void HAL_I2C_MasterRxCpltCallback(I2C_HandleTypeDef *I2cHandle)
{
  /* Toggle LED_GREEN: Transfer in reception process is correct */
  BSP_LED_Toggle(LED_GREEN);
}
#else
void HAL_I2C_SlaveRxCpltCallback(I2C_HandleTypeDef *I2cHandle)
{
  /* Restore config: clock, GPIO... */
  SystemClock_Config();

  /* Restore GPIO configuration */
  BSP_LED_Init(LED_GREEN);
  BSP_LED_Init(LED_BLUE);

  /* Wake Up from Stop Mode */
  /* Turn LED_BLUE off */
  BSP_LED_Off(LED_BLUE);

  /* Turn On LED_GREEN: Transfer in reception process is correct */
  BSP_LED_On(LED_GREEN);
}
#endif /* MASTER_BOARD */

/**
  * @brief  I2C error callbacks.
  * @param  I2cHandle: I2C handle
  * @note   This example shows a simple way to report transfer error, and you can
  *         add your own implementation.
  * @retval None
  */
#ifdef MASTER_BOARD
void HAL_I2C_ErrorCallback(I2C_HandleTypeDef *I2cHandle)
{
  /* Turn LED_RED on: Transfer error in reception/transmission process */
  BSP_LED_On(LED_RED); 
}
#else
void HAL_I2C_ErrorCallback(I2C_HandleTypeDef *I2cHandle)
{
  /* Restore config: clock, GPIO... */
  SystemClock_Config();

  /* Restore GPIO configuration */
  BSP_LED_Init(LED_RED);
  /* Turn LED_RED on: Transfer error in reception/transmission process */
  BSP_LED_On(LED_RED); 
}
#endif /* MASTER_BOARD */

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
  /* Turn LED_RED on */
  BSP_LED_On(LED_RED);
  while(1)
  {
  }
}

/**
  * @brief  Compares two buffers.
  * @param  pBuffer1, pBuffer2: buffers to be compared.
  * @param  BufferLength: buffer's length
  * @retval 0  : pBuffer1 identical to pBuffer2
  *         >0 : pBuffer1 differs from pBuffer2
  */
static uint16_t Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength)
{
  while (BufferLength--)
  {
    if ((*pBuffer1) != *pBuffer2)
    {
      return BufferLength;
    }
    pBuffer1++;
    pBuffer2++;
  }

  return 0;
}

#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

/**
  * @}
  */ 

/**
  * @}
  */