/**
  ******************************************************************************
  * @file    Examples_LL/SPI/SPI_TwoBoards_FullDuplex_IT/Src/main.c
  * @author  MCD Application Team
  * @brief   This example describes how to send/receive bytes over SPI IP using
  *          the STM32F3xx SPI LL API.
  *          Peripheral initialization done using LL unitary services functions.
  ******************************************************************************
  * @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_LL_Examples
  * @{
  */

/** @addtogroup SPI_TwoBoards_FullDuplex_IT
  * @{
  */

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

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
__IO uint8_t ubButtonPress = 0;

/* Buffer used for transmission */
uint8_t aTxBuffer[] = "**** SPI_TwoBoards_FullDuplex_IT communication **** SPI_TwoBoards_FullDuplex_IT communication **** SPI_TwoBoards_FullDuplex_IT communication ****";
uint8_t ubNbDataToTransmit = sizeof(aTxBuffer);
__IO uint8_t ubTransmitIndex = 0;

/* Buffer used for reception */
uint8_t aRxBuffer[sizeof(aTxBuffer)];
uint8_t ubNbDataToReceive = sizeof(aTxBuffer);
__IO uint8_t ubReceiveIndex = 0;


/* Private function prototypes -----------------------------------------------*/
void     SystemClock_Config(void);
void     Configure_SPI(void);
void     Activate_SPI(void);
void     LED_Init(void);
void     LED_On(void);
void     LED_Blinking(uint32_t Period);
#ifdef MASTER_BOARD
void     LED_Off(void);
void     UserButton_Init(void);
void     WaitForUserButtonPress(void);
#endif
void     WaitAndCheckEndOfTransfer(void);
uint8_t  Buffercmp8(uint8_t* pBuffer1, uint8_t* pBuffer2, uint8_t BufferLength);
/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /* Configure the system clock to 64 MHz */
  SystemClock_Config();

  /* Initialize LED2 */
  LED_Init();

  /* Configure the SPI1 parameters */
  Configure_SPI();

#ifdef MASTER_BOARD
  /* Initialize User push-button in EXTI mode */
  UserButton_Init();

  /* Wait for User push-button press to start transfer */
  WaitForUserButtonPress();
#endif

  /* Enable the SPI1 peripheral */
  Activate_SPI();

  /* Wait for the end of the transfer and check received data */
  /* LED blinking FAST during waiting time */
  WaitAndCheckEndOfTransfer();

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


/**
  * @brief  This function configures SPI1.
  * @note  This function is used to :
  *        -1- Enables GPIO clock and configures the SPI1 pins.
  *        -2- Configure NVIC for SPI1.
  *        -3- Configure SPI1 functional parameters.
  * @note   Peripheral configuration is minimal configuration from reset values.
  *         Thus, some useless LL unitary functions calls below are provided as
  *         commented examples - setting is default configuration from reset.
  * @param  None
  * @retval None
  */
void Configure_SPI(void)
{
  /* (1) Enables GPIO clock and configures the SPI1 pins ********************/
  /* Enable the peripheral clock of GPIOB */
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOB);

  /* Configure SCK Pin connected to pin 31 of CN10 connector */
  LL_GPIO_SetPinMode(GPIOB, LL_GPIO_PIN_3, LL_GPIO_MODE_ALTERNATE);
  LL_GPIO_SetAFPin_0_7(GPIOB, LL_GPIO_PIN_3, LL_GPIO_AF_5);
  LL_GPIO_SetPinSpeed(GPIOB, LL_GPIO_PIN_3, LL_GPIO_SPEED_FREQ_HIGH);
  LL_GPIO_SetPinPull(GPIOB, LL_GPIO_PIN_3, LL_GPIO_PULL_DOWN);

  /* Configure MISO Pin connected to pin 27 of CN10 connector */
  LL_GPIO_SetPinMode(GPIOB, LL_GPIO_PIN_4, LL_GPIO_MODE_ALTERNATE);
  LL_GPIO_SetAFPin_0_7(GPIOB, LL_GPIO_PIN_4, LL_GPIO_AF_5);
  LL_GPIO_SetPinSpeed(GPIOB, LL_GPIO_PIN_4, LL_GPIO_SPEED_FREQ_HIGH);
  LL_GPIO_SetPinPull(GPIOB, LL_GPIO_PIN_4, LL_GPIO_PULL_DOWN);

  /* Configure MOSI Pin connected to pin 29 of CN10 connector */
  LL_GPIO_SetPinMode(GPIOB, LL_GPIO_PIN_5, LL_GPIO_MODE_ALTERNATE);
  LL_GPIO_SetAFPin_0_7(GPIOB, LL_GPIO_PIN_5, LL_GPIO_AF_5);
  LL_GPIO_SetPinSpeed(GPIOB, LL_GPIO_PIN_5, LL_GPIO_SPEED_FREQ_HIGH);
  LL_GPIO_SetPinPull(GPIOB, LL_GPIO_PIN_5, LL_GPIO_PULL_DOWN);

  /* (2) Configure NVIC for SPI1 transfer complete/error interrupts **********/
  /* Set priority for SPI1_IRQn */
  NVIC_SetPriority(SPI1_IRQn, 0);
  /* Enable SPI1_IRQn           */
  NVIC_EnableIRQ(SPI1_IRQn);

  /* (3) Configure SPI1 functional parameters ********************************/

  /* Enable the peripheral clock of GPIOB */
  LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_SPI1);

  /* Configure SPI1 communication */
  LL_SPI_SetBaudRatePrescaler(SPI1, LL_SPI_BAUDRATEPRESCALER_DIV256);
  LL_SPI_SetTransferDirection(SPI1,LL_SPI_FULL_DUPLEX);
  LL_SPI_SetClockPhase(SPI1, LL_SPI_PHASE_2EDGE);
  LL_SPI_SetClockPolarity(SPI1, LL_SPI_POLARITY_HIGH);
  /* Reset value is LL_SPI_MSB_FIRST */
  //LL_SPI_SetTransferBitOrder(SPI1, LL_SPI_MSB_FIRST);
  LL_SPI_SetDataWidth(SPI1, LL_SPI_DATAWIDTH_8BIT);
  LL_SPI_SetNSSMode(SPI1, LL_SPI_NSS_SOFT);
  LL_SPI_SetRxFIFOThreshold(SPI1, LL_SPI_RX_FIFO_TH_QUARTER);
#ifdef MASTER_BOARD
  LL_SPI_SetMode(SPI1, LL_SPI_MODE_MASTER);
#else
  /* Reset value is LL_SPI_MODE_SLAVE */
  //LL_SPI_SetMode(SPI1, LL_SPI_MODE_SLAVE);
#endif /* MASTER_BOARD */

  /* Configure SPI1 transfer interrupts */
  /* Enable RXNE  Interrupt             */
  LL_SPI_EnableIT_RXNE(SPI1);
  /* Enable TXE   Interrupt             */
  LL_SPI_EnableIT_TXE(SPI1);
  /* Enable Error Interrupt             */
  LL_SPI_EnableIT_ERR(SPI1);
}

/**
  * @brief  This function Activate SPI1
  * @param  None
  * @retval None
  */
void Activate_SPI(void)
{
  /* Enable SPI1 */
  LL_SPI_Enable(SPI1);
}

/**
  * @brief  Initialize LED2.
  * @param  None
  * @retval None
  */
void LED_Init(void)
{
  /* Enable the LED2 Clock */
  LED2_GPIO_CLK_ENABLE();

  /* Configure IO in output push-pull mode to drive external LED2 */
  LL_GPIO_SetPinMode(LED2_GPIO_PORT, LED2_PIN, LL_GPIO_MODE_OUTPUT);
  /* Reset value is LL_GPIO_OUTPUT_PUSHPULL */
  //LL_GPIO_SetPinOutputType(LED2_GPIO_PORT, LED2_PIN, LL_GPIO_OUTPUT_PUSHPULL);
  /* Reset value is LL_GPIO_SPEED_FREQ_LOW */
  //LL_GPIO_SetPinSpeed(LED2_GPIO_PORT, LED2_PIN, LL_GPIO_SPEED_FREQ_LOW);
  /* Reset value is LL_GPIO_PULL_NO */
  //LL_GPIO_SetPinPull(LED2_GPIO_PORT, LED2_PIN, LL_GPIO_PULL_NO);
}

/**
  * @brief  Turn-on LED2.
  * @param  None
  * @retval None
  */
void LED_On(void)
{
  /* Turn LED2 on */
  LL_GPIO_SetOutputPin(LED2_GPIO_PORT, LED2_PIN);
}

#ifdef MASTER_BOARD
/**
  * @brief  Turn-off LED2.
  * @param  None
  * @retval None
  */
void LED_Off(void)
{
  /* Turn LED2 off */
  LL_GPIO_ResetOutputPin(LED2_GPIO_PORT, LED2_PIN);
}
#endif

/**
  * @brief  Set LED2 to Blinking mode for an infinite loop (toggle period based on value provided as input parameter).
  * @param  Period : Period of time (in ms) between each toggling of LED
  *   This parameter can be user defined values. Pre-defined values used in that example are :
  *     @arg LED_BLINK_FAST : Fast Blinking
  *     @arg LED_BLINK_SLOW : Slow Blinking
  *     @arg LED_BLINK_ERROR : Error specific Blinking
  * @retval None
  */
void LED_Blinking(uint32_t Period)
{
  /* Toggle LED2 in an infinite loop */
  while (1)
  {
    LL_GPIO_TogglePin(LED2_GPIO_PORT, LED2_PIN);
    LL_mDelay(Period);
  }
}

#ifdef MASTER_BOARD
/**
  * @brief  Configures User push-button in GPIO or EXTI Line Mode.
  * @param  None
  * @retval None
  */
void UserButton_Init(void)
{
  /* Enable the BUTTON Clock */
  USER_BUTTON_GPIO_CLK_ENABLE();

  /* Configure GPIO for BUTTON */
  LL_GPIO_SetPinMode(USER_BUTTON_GPIO_PORT, USER_BUTTON_PIN, LL_GPIO_MODE_INPUT);
  LL_GPIO_SetPinPull(USER_BUTTON_GPIO_PORT, USER_BUTTON_PIN, LL_GPIO_PULL_NO);

  /* Connect External Line to the GPIO*/
  USER_BUTTON_SYSCFG_SET_EXTI();

  /* Enable a rising trigger External line 13 Interrupt */
  USER_BUTTON_EXTI_LINE_ENABLE();
  USER_BUTTON_EXTI_FALLING_TRIG_ENABLE();

  /* Configure NVIC for USER_BUTTON_EXTI_IRQn */
  NVIC_EnableIRQ(USER_BUTTON_EXTI_IRQn);
  NVIC_SetPriority(USER_BUTTON_EXTI_IRQn, 0x03);
}

/**
  * @brief  Wait for User push-button press to start transfer.
  * @param  None
  * @retval None
  */
  /*  */
void WaitForUserButtonPress(void)
{
  while (ubButtonPress == 0)
  {
    LL_GPIO_TogglePin(LED2_GPIO_PORT, LED2_PIN);
    LL_mDelay(LED_BLINK_FAST);
  }
  /* Ensure that LED2 is turned Off */
  LED_Off();
}
#endif

/**
  * @brief  Wait end of transfer and check if received Data are well.
  * @param  None
  * @retval None
  */
void WaitAndCheckEndOfTransfer(void)
{
  /* 1 - Wait end of transmission */
  while (ubTransmitIndex != ubNbDataToTransmit)
  {
  }
  /* Disable TXE Interrupt */
  LL_SPI_DisableIT_TXE(SPI1);

  /* 2 - Wait end of reception */
  while (ubNbDataToReceive > ubReceiveIndex)
  {
  }
  /* Disable RXNE Interrupt */
  LL_SPI_DisableIT_RXNE(SPI1);

  /* 3 - Compare Transmit data to receive data */
  if(Buffercmp8((uint8_t*)aTxBuffer, (uint8_t*)aRxBuffer, ubNbDataToTransmit))
  {
    /* Processing Error */
    LED_Blinking(LED_BLINK_ERROR);
  }
  else
  {
    /* Turn On Led if data are well received */
    LED_On();
  }
}

/**
* @brief Compares two 8-bit buffers and returns the comparison result.
* @param pBuffer1: pointer to the source buffer to be compared to.
* @param pBuffer2: pointer to the second source buffer to be compared to the first.
* @param BufferLength: buffer's length.
* @retval   0: Comparison is OK (the two Buffers are identical)
*           Value different from 0: Comparison is NOK (Buffers are different)
*/
uint8_t Buffercmp8(uint8_t* pBuffer1, uint8_t* pBuffer2, uint8_t BufferLength)
{
  while (BufferLength--)
  {
    if (*pBuffer1 != *pBuffer2)
    {
      return 1;
    }

    pBuffer1++;
    pBuffer2++;
  }

  return 0;
}

/**
  * @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
  *            PLLMUL                         = 16
  *            Flash Latency(WS)              = 2
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  /* Set FLASH latency */ 
  LL_FLASH_SetLatency(LL_FLASH_LATENCY_2);

  /* Enable HSI if not already activated*/
  if (LL_RCC_HSI_IsReady() == 0)
  {
    /* Enable HSI and wait for activation*/
    LL_RCC_HSI_Enable(); 
    while(LL_RCC_HSI_IsReady() != 1)
    {
    };
  }

  /* Main PLL configuration and activation */
  LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSI_DIV_2, LL_RCC_PLL_MUL_16);
  
  LL_RCC_PLL_Enable();
  while(LL_RCC_PLL_IsReady() != 1) 
  {
  };
  
  /* Sysclk activation on the main PLL */
  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL)
  {
  };
  
  /* Set APB1 & APB2 prescaler*/
  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_2);
  LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_1);
  
  /* Set systick to 1ms in using frequency set to 64MHz */
  /* This frequency can be calculated through LL RCC macro */
  /* ex: __LL_RCC_CALC_PLLCLK_FREQ ((HSI_VALUE / 2), LL_RCC_PLL_MUL_16) */
  LL_Init1msTick(64000000);
  
  /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
  LL_SetSystemCoreClock(64000000);
}

/******************************************************************************/
/*   USER IRQ HANDLER TREATMENT Functions                                     */
/******************************************************************************/
/**
  * @brief  Function to manage User push-button
  * @param  None
  * @retval None
  */
void UserButton_Callback(void)
{
  /* Update User push-button variable : to be checked in waiting loop in main program */
  ubButtonPress = 1;
}

/**
  * @brief  Function called from SPI1 IRQ Handler when RXNE flag is set
  *         Function is in charge of retrieving received byte from SPI lines.
  * @param  None
  * @retval None
  */
void  SPI1_Rx_Callback(void)
{
  /* Read character in Data register.
  RXNE flag is cleared by reading data in DR register */
  aRxBuffer[ubReceiveIndex++] = LL_SPI_ReceiveData8(SPI1);
}

/**
  * @brief  Function called from SPI1 IRQ Handler when TXE flag is set
  *         Function is in charge  to transmit byte on SPI lines.
  * @param  None
  * @retval None
  */
void  SPI1_Tx_Callback(void)
{
  /* Write character in Data register.
  TXE flag is cleared by reading data in DR register */
  LL_SPI_TransmitData8(SPI1, aTxBuffer[ubTransmitIndex++]);
}

/**
  * @brief  Function called in case of error detected in SPI IT Handler
  * @param  None
  * @retval None
  */
void SPI1_TransferError_Callback(void)
{
  /* Disable RXNE  Interrupt             */
  LL_SPI_DisableIT_RXNE(SPI1);

  /* Disable TXE   Interrupt             */
  LL_SPI_DisableIT_TXE(SPI1);

  /* Set LED2 to Blinking mode to indicate error occurs */
  LED_Blinking(LED_BLINK_ERROR);
}

#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", file, line) */

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

/**
  * @}
  */

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