/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    Examples_LL/USART/USART_Communication_TxRx_DMA_Init/Src/main.c
  * @author  MCD Application Team
  * @brief   This example describes how to send/receive bytes over USART IP using
  *          the STM32WLxx USART LL API in DMA mode.
  *          Peripheral initialization done using LL unitary services functions.
  ******************************************************************************
  * @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 */

/* USER CODE END PD */

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

/* USER CODE END PM */

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

/* USER CODE BEGIN PV */

__IO uint8_t ubButtonPress = 0;
__IO uint8_t ubSend = 0;
/* Buffer used for transmission */
const uint8_t aTxBuffer[] = "STM32WLxx USART LL API Example : TX/RX in DMA mode\r\nConfiguration UART 115200 bps, 8 data bit/1 stop bit/No parity/No HW flow control\r\nPlease enter 'END' string ...\r\n";
uint8_t ubNbDataToTransmit = sizeof(aTxBuffer);
__IO uint8_t ubTransmissionComplete = 0;

/* Buffer used for reception */
const uint8_t aStringToReceive[] = "END";
uint8_t ubNbDataToReceive = sizeof(aStringToReceive) - 1;
uint8_t aRxBuffer[sizeof(aStringToReceive) - 1];
__IO uint8_t ubReceptionComplete = 0;

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_USART2_UART_Init(void);
/* USER CODE BEGIN PFP */

void     StartTransfers(void);
void     LED_On(void);
void     LED_Blinking(uint32_t Period);
void     LED_Off(void);
void     UserButton_Init(void);
void     WaitForUserButtonPress(void);
void     WaitAndCheckEndOfTransfer(void);
uint8_t  Buffercmp8(uint8_t *pBuffer1, uint8_t *pBuffer2, uint8_t BufferLength);

/* 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. */

  /* System interrupt init*/
  NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

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

  /* USER CODE BEGIN SysInit */
  /* Initialize User push-button (B1) in EXTI mode */
  UserButton_Init();
  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_USART2_UART_Init();
  /* USER CODE BEGIN 2 */
  /* Wait for User push-button (B1) press to start transfer */
  WaitForUserButtonPress();

  /* Initiate DMA transfers */
  StartTransfers();

  /* Wait for the end of the transfer and check received data */
  WaitAndCheckEndOfTransfer();

  /* USER CODE END 2 */

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

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  LL_FLASH_SetLatency(LL_FLASH_LATENCY_2);
  while(LL_FLASH_GetLatency() != LL_FLASH_LATENCY_2)
  {
  }

  LL_PWR_SetRegulVoltageScaling(LL_PWR_REGU_VOLTAGE_SCALE1);
  LL_RCC_MSI_Enable();

   /* Wait till MSI is ready */
  while(LL_RCC_MSI_IsReady() != 1)
  {
  }

  LL_RCC_MSI_EnableRangeSelection();
  LL_RCC_MSI_SetRange(LL_RCC_MSIRANGE_11);
  LL_RCC_MSI_SetCalibTrimming(0);
  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_MSI);

   /* Wait till System clock is ready */
  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_MSI)
  {
  }

  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
  LL_RCC_SetAHB3Prescaler(LL_RCC_SYSCLK_DIV_1);
  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_1);
  LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_1);

  LL_Init1msTick(48000000);

  /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
  LL_SetSystemCoreClock(48000000);
}

/**
  * @brief USART2 Initialization Function
  * @param None
  * @retval None
  */
static void MX_USART2_UART_Init(void)
{

  /* USER CODE BEGIN USART2_Init 0 */

  /* USER CODE END USART2_Init 0 */

  LL_USART_InitTypeDef USART_InitStruct = {0};

  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  LL_RCC_SetUSARTClockSource(LL_RCC_USART2_CLKSOURCE_PCLK1);

  /* Peripheral clock enable */
  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_USART2);

  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOA);
  /**USART2 GPIO Configuration
  PA3   ------> USART2_RX
  PA2   ------> USART2_TX
  */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_3|LL_GPIO_PIN_2;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_HIGH;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_UP;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_7;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* USART2 DMA Init */

  /* USART2_TX Init */
  LL_DMA_SetPeriphRequest(DMA1, LL_DMA_CHANNEL_1, LL_DMAMUX_REQ_USART2_TX);

  LL_DMA_SetDataTransferDirection(DMA1, LL_DMA_CHANNEL_1, LL_DMA_DIRECTION_MEMORY_TO_PERIPH);

  LL_DMA_SetChannelPriorityLevel(DMA1, LL_DMA_CHANNEL_1, LL_DMA_PRIORITY_HIGH);

  LL_DMA_SetMode(DMA1, LL_DMA_CHANNEL_1, LL_DMA_MODE_NORMAL);

  LL_DMA_SetPeriphIncMode(DMA1, LL_DMA_CHANNEL_1, LL_DMA_PERIPH_NOINCREMENT);

  LL_DMA_SetMemoryIncMode(DMA1, LL_DMA_CHANNEL_1, LL_DMA_MEMORY_INCREMENT);

  LL_DMA_SetPeriphSize(DMA1, LL_DMA_CHANNEL_1, LL_DMA_PDATAALIGN_BYTE);

  LL_DMA_SetMemorySize(DMA1, LL_DMA_CHANNEL_1, LL_DMA_MDATAALIGN_BYTE);

  LL_DMA_DisableChannelPrivilege(DMA1, LL_DMA_CHANNEL_1);

  /* USART2_RX Init */
  LL_DMA_SetPeriphRequest(DMA1, LL_DMA_CHANNEL_2, LL_DMAMUX_REQ_USART2_RX);

  LL_DMA_SetDataTransferDirection(DMA1, LL_DMA_CHANNEL_2, LL_DMA_DIRECTION_PERIPH_TO_MEMORY);

  LL_DMA_SetChannelPriorityLevel(DMA1, LL_DMA_CHANNEL_2, LL_DMA_PRIORITY_HIGH);

  LL_DMA_SetMode(DMA1, LL_DMA_CHANNEL_2, LL_DMA_MODE_NORMAL);

  LL_DMA_SetPeriphIncMode(DMA1, LL_DMA_CHANNEL_2, LL_DMA_PERIPH_NOINCREMENT);

  LL_DMA_SetMemoryIncMode(DMA1, LL_DMA_CHANNEL_2, LL_DMA_MEMORY_INCREMENT);

  LL_DMA_SetPeriphSize(DMA1, LL_DMA_CHANNEL_2, LL_DMA_PDATAALIGN_BYTE);

  LL_DMA_SetMemorySize(DMA1, LL_DMA_CHANNEL_2, LL_DMA_MDATAALIGN_BYTE);

  LL_DMA_DisableChannelPrivilege(DMA1, LL_DMA_CHANNEL_2);

  /* USART2 interrupt Init */
  NVIC_SetPriority(USART2_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
  NVIC_EnableIRQ(USART2_IRQn);

  /* USER CODE BEGIN USART2_Init 1 */
  /* Configure the DMA functional parameters for transmission */
  LL_DMA_ConfigAddresses(DMA1, LL_DMA_CHANNEL_1,
                         (uint32_t)aTxBuffer,
                         LL_USART_DMA_GetRegAddr(USART2, LL_USART_DMA_REG_DATA_TRANSMIT),
                         LL_DMA_GetDataTransferDirection(DMA1, LL_DMA_CHANNEL_1));
  LL_DMA_SetDataLength(DMA1, LL_DMA_CHANNEL_1, ubNbDataToTransmit);

  /* Configure the DMA functional parameters for reception */
  LL_DMA_ConfigAddresses(DMA1, LL_DMA_CHANNEL_2,
                         LL_USART_DMA_GetRegAddr(USART2, LL_USART_DMA_REG_DATA_RECEIVE),
                         (uint32_t)aRxBuffer,
                         LL_DMA_GetDataTransferDirection(DMA1, LL_DMA_CHANNEL_2));
  LL_DMA_SetDataLength(DMA1, LL_DMA_CHANNEL_2, ubNbDataToReceive);

  /* Enable DMA transfer complete/error interrupts  */
  LL_DMA_EnableIT_TC(DMA1, LL_DMA_CHANNEL_1);
  LL_DMA_EnableIT_TE(DMA1, LL_DMA_CHANNEL_1);
  LL_DMA_EnableIT_TC(DMA1, LL_DMA_CHANNEL_2);
  LL_DMA_EnableIT_TE(DMA1, LL_DMA_CHANNEL_2);
  /* USER CODE END USART2_Init 1 */
  USART_InitStruct.PrescalerValue = LL_USART_PRESCALER_DIV1;
  USART_InitStruct.BaudRate = 115200;
  USART_InitStruct.DataWidth = LL_USART_DATAWIDTH_8B;
  USART_InitStruct.StopBits = LL_USART_STOPBITS_1;
  USART_InitStruct.Parity = LL_USART_PARITY_NONE;
  USART_InitStruct.TransferDirection = LL_USART_DIRECTION_TX_RX;
  USART_InitStruct.HardwareFlowControl = LL_USART_HWCONTROL_NONE;
  USART_InitStruct.OverSampling = LL_USART_OVERSAMPLING_16;
  LL_USART_Init(USART2, &USART_InitStruct);
  LL_USART_SetTXFIFOThreshold(USART2, LL_USART_FIFOTHRESHOLD_1_8);
  LL_USART_SetRXFIFOThreshold(USART2, LL_USART_FIFOTHRESHOLD_1_8);
  LL_USART_DisableFIFO(USART2);
  LL_USART_ConfigAsyncMode(USART2);

  /* USER CODE BEGIN WKUPType USART2 */

  /* USER CODE END WKUPType USART2 */

  LL_USART_Enable(USART2);

  /* Polling USART2 initialisation */
  while((!(LL_USART_IsActiveFlag_TEACK(USART2))) || (!(LL_USART_IsActiveFlag_REACK(USART2))))
  {
  }
  /* USER CODE BEGIN USART2_Init 2 */
  /* USER CODE END USART2_Init 2 */

}

/**
  * Enable DMA controller clock
  */
static void MX_DMA_Init(void)
{

  /* Init with LL driver */
  /* DMA controller clock enable */
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_DMAMUX1);
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_DMA1);

  /* DMA interrupt init */
  /* DMA1_Channel1_IRQn interrupt configuration */
  NVIC_SetPriority(DMA1_Channel1_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
  NVIC_EnableIRQ(DMA1_Channel1_IRQn);
  /* DMA1_Channel2_IRQn interrupt configuration */
  NVIC_SetPriority(DMA1_Channel2_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
  NVIC_EnableIRQ(DMA1_Channel2_IRQn);

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOB);
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOA);

  /**/
  LL_GPIO_ResetOutputPin(LED2_GPIO_Port, LED2_Pin);

  /**/
  GPIO_InitStruct.Pin = LED2_Pin;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(LED2_GPIO_Port, &GPIO_InitStruct);

}

/* USER CODE BEGIN 4 */

/**
  * @brief  This function initiates TX and RX DMA transfers by enabling DMA channels
  * @param  None
  * @retval None
  */
void StartTransfers(void)
{
  /* Enable DMA RX Interrupt */
  LL_USART_EnableDMAReq_RX(USART2);

  /* Enable DMA TX Interrupt */
  LL_USART_EnableDMAReq_TX(USART2);

  /* Enable DMA Channel Rx */
  LL_DMA_EnableChannel(DMA1, LL_DMA_CHANNEL_2);

  /* Enable DMA Channel Tx */
  LL_DMA_EnableChannel(DMA1, LL_DMA_CHANNEL_1);
}

/**
  * @brief  Turn-on LED2.
  * @param  None
  * @retval None
  */
void LED_On(void)
{
  /* Turn LED2 on */
  LL_GPIO_SetOutputPin(LED2_GPIO_Port, LED2_Pin);
}

/**
  * @brief  Turn-off LED2.
  * @param  None
  * @retval None
  */
void LED_Off(void)
{
  /* Turn LED2 off */
  LL_GPIO_ResetOutputPin(LED2_GPIO_Port, LED2_Pin);
}

/**
  * @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);
  }
}

/**
  * @brief  Configures User push-button (B1) 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_UP);

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

  /* Enable a rising trigger External line 0 Interrupt */
  USER_BUTTON_EXTI_LINE_ENABLE();
  USER_BUTTON_EXTI_FALLING_TRIG_ENABLE();

  /* Configure NVIC for USER_BUTTON_EXTI_IRQn */
  NVIC_SetPriority(USER_BUTTON_EXTI_IRQn, 3);
  NVIC_EnableIRQ(USER_BUTTON_EXTI_IRQn);
}

/**
  * @brief  Wait for User push-button (B1) 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();
}

/**
  * @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 (ubTransmissionComplete != 1)
  {
  }
  /* Disable DMA1 Tx Channel */
  LL_DMA_DisableChannel(DMA1, LL_DMA_CHANNEL_1);

  /* 2 - Wait end of reception */
  while (ubReceptionComplete != 1)
  {
  }
  /* Disable DMA1 Rx Channel */
  LL_DMA_DisableChannel(DMA1, LL_DMA_CHANNEL_2);

  /* 3 - Compare received string to expected one */
  if (Buffercmp8((uint8_t *)aStringToReceive, (uint8_t *)aRxBuffer, ubNbDataToReceive))
  {
    /* 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;
}

/******************************************************************************/
/*   USER IRQ HANDLER TREATMENT Functions                                     */
/******************************************************************************/
/**
  * @brief  Function to manage User push-button (B1)
  * @param  None
  * @retval None
  */
void UserButton_Callback(void)
{
  /* Update User push-button (B1) variable : to be checked in waiting loop in main program */
  ubButtonPress = 1;
}

/**
  * @brief  Function called from DMA1 IRQ Handler when Tx transfer is completed
  * @param  None
  * @retval None
  */
void DMA1_TransmitComplete_Callback(void)
{
  /* DMA Tx transfer completed */
  ubTransmissionComplete = 1;
}

/**
  * @brief  Function called from DMA1 IRQ Handler when Rx transfer is completed
  * @param  None
  * @retval None
  */
void DMA1_ReceiveComplete_Callback(void)
{
  /* DMA Rx transfer completed */
  ubReceptionComplete = 1;
}

/**
  * @brief  Function called in case of error detected in USART IT Handler
  * @param  None
  * @retval None
  */
void USART_TransferError_Callback(void)
{
  /* Disable DMA1 Tx Channel */
  LL_DMA_DisableChannel(DMA1, LL_DMA_CHANNEL_1);

  /* Disable DMA1 Rx Channel */
  LL_DMA_DisableChannel(DMA1, LL_DMA_CHANNEL_2);

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

/* 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 */
  /* User can add his own implementation to report the HAL error return state */

  /* 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,
     tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
