STM32F401用配置串口2的dma，并用串口dma发送数据给上位机并可以接受来自上位机的数据，请只用c语言详细编写相关库函数代码

以下是使用STM32F401配置串口2的DMA发送和接收数据的C语言库函数代码：

首先，需要在stm32f4xx_hal_conf.h文件中打开DMA库：

#define HAL_DMA_MODULE_ENABLED

然后，在main.c文件中，需要初始化串口2和DMA，代码如下：

#include "main.h"
#include "stm32f4xx_hal.h"

UART_HandleTypeDef huart2;
DMA_HandleTypeDef hdma_usart2_tx;
DMA_HandleTypeDef hdma_usart2_rx;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_USART2_UART_Init(void);

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_USART2_UART_Init();

  while (1)
  {

  }
}

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;

  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = 16;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = 16;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  RCC_ClkInitStruct.ClockType = 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_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_USART2_UART_Init(void)
{
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_DMA_Init(void)
{
  __HAL_RCC_DMA1_CLK_ENABLE();

  HAL_NVIC_SetPriority(DMA1_Stream6_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream6_IRQn);

  hdma_usart2_tx.Instance = DMA1_Stream6;
  hdma_usart2_tx.Init.Channel = DMA_CHANNEL_4;
  hdma_usart2_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
  hdma_usart2_tx.Init.PeriphInc = DMA_PINC_DISABLE;
  hdma_usart2_tx.Init.MemInc = DMA_MINC_ENABLE;
  hdma_usart2_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
  hdma_usart2_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
  hdma_usart2_tx.Init.Mode = DMA_NORMAL;
  hdma_usart2_tx.Init.Priority = DMA_PRIORITY_LOW;
  hdma_usart2_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
  if (HAL_DMA_Init(&hdma_usart2_tx) != HAL_OK)
  {
    Error_Handler();
  }

  __HAL_LINKDMA(&huart2,hdmatx,hdma_usart2_tx);

  HAL_NVIC_SetPriority(DMA1_Stream5_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream5_IRQn);

  hdma_usart2_rx.Instance = DMA1_Stream5;
  hdma_usart2_rx.Init.Channel = DMA_CHANNEL_4;
  hdma_usart2_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
  hdma_usart2_rx.Init.PeriphInc = DMA_PINC_DISABLE;
  hdma_usart2_rx.Init.MemInc = DMA_MINC_ENABLE;
  hdma_usart2_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
  hdma_usart2_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
  hdma_usart2_rx.Init.Mode = DMA_CIRCULAR;
  hdma_usart2_rx.Init.Priority = DMA_PRIORITY_LOW;
  hdma_usart2_rx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
  if (HAL_DMA_Init(&hdma_usart2_rx) != HAL_OK)
  {
    Error_Handler();
  }

  __HAL_LINKDMA(&huart2,hdmarx,hdma_usart2_rx);

  HAL_UART_Receive_DMA(&huart2, (uint8_t *)USART2_RxBuffer, USART2_RX_BUFFER_SIZE);
}

void DMA1_Stream6_IRQHandler(void)
{
  HAL_DMA_IRQHandler(&hdma_usart2_tx);
}

void DMA1_Stream5_IRQHandler(void)
{
  HAL_DMA_IRQHandler(&hdma_usart2_rx);
}

void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(uartHandle->Instance==USART2)
  {
    __HAL_RCC_USART2_CLK_ENABLE();

    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**USART2 GPIO Configuration
    PA2     ------> USART2_TX
    PA3     ------> USART2_RX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_2|GPIO_PIN_3;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF7_USART2;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
  }
}

void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
{
  if(uartHandle->Instance==USART2)
  {
    __HAL_RCC_USART2_CLK_DISABLE();

    /**USART2 GPIO Configuration
    PA2     ------> USART2_TX
    PA3     ------> USART2_RX
    */
    HAL_GPIO_DeInit(GPIOA, GPIO_PIN_2|GPIO_PIN_3);
  }
}

在上面的代码中，使用了一个USART2_RxBuffer缓冲区来存储接收到的数据，并且使用了DMA模式进行发送和接收。

接下来，需要编写发送数据的函数，这里使用了HAL库函数进行配置：

void UART_SendData_DMA(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size)
{
  HAL_UART_Transmit_DMA(huart, pData, Size);
}

最后，还需要编写接收数据的函数：

void UART_ReceiveData_DMA(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size)
{
  HAL_UART_Receive_DMA(huart, pData, Size);
}

这样，就完成了串口2的DMA配置，可以通过调用UART_SendData_DMA和UART_ReceiveData_DMA函数来发送和接收数据。