串口8无法使用DMA方式接收

发布于 2024-11-19 13:17:12 浏览：373 订阅该版

使用rtthread的4.0.5在正点原子stm32f4的板子上例程基础上增加了uart8，使用串口V1.0版本，使用的STM32F427VGT6。
已经在rtconfig.h中定义了

```c
#define BSP_USING_UART7
#define BSP_UART7_RX_USING_DMA
#define BSP_USING_UART8
#define BSP_UART8_RX_USING_DMA
```
在board.h中定义了
```c
#define BSP_USING_UART7
#define BSP_UART7_TX_PIN       "PE8"
#define BSP_UART7_RX_PIN       "PE7"
#define BSP_USING_UART8
#define BSP_UART8_TX_PIN       "PE1"
#define BSP_UART8_RX_PIN       "PE0"
```
在stm32f4xx_hal_conf.h中定义了
```c
#define HAL_DMA_MODULE_ENABLED
```
参考DMA接收例程，完成如下函数
```c
void South_Uart_init(void)
{
	Uart7_info = rt_device_find(Uart7_INFO);
    if (!Uart7_info)
    {
        LOG_E("find Uart7_INFO %s failed!", Uart7_INFO);
        return;
    }
    Uart8_wave = rt_device_find(UART8_WAVE);
    if (!Uart8_wave)
    {
        rt_kprintf("find Uart8_wave  %s failed!", Uart8_wave);
        return;
    }
	rt_device_control(Uart7_info, RT_DEVICE_CTRL_CONFIG, &uart7_info_config);
    rt_device_control(Uart8_wave, RT_DEVICE_CTRL_CONFIG, &config);
    static char msg_pool[256];
    /* 初始化消息队列 */
    rt_mq_init(&rx8_mq, "rx8_mq", msg_pool, sizeof(struct rx_msg), sizeof(msg_pool), RT_IPC_FLAG_FIFO);
	rt_err_t result1 = rt_device_open(Uart7_info, RT_DEVICE_FLAG_DMA_RX);
    LOG_D("rt_device result=%d", result1);
    /* 以 DMA 接收及轮询发送方式打开串口设备 */
    rt_err_t result = rt_device_open(Uart8_wave, RT_DEVICE_FLAG_DMA_RX);
    /* 设置接收回调函数 */
    rt_device_set_rx_indicate(Uart8_wave, uart8_wave_rx_ind);
    rt_size_t tx_size = rt_device_write(Uart8_wave, 0, "123", sizeof("123"));
    LOG_D("rt_device_write(Uart8_wave) tx=%d result=%d", tx_size,result);
}
```
打印出
```
rt_device result=0
rt_device_write(Uart8_wave) tx=0 result=-8
```
串口7可以设置为DMA接收；但是串口8不行，同时无法进入串口中断接收函数；
如果修改为中断接收
```
rt_err_t result = rt_device_open(Uart8_wave, RT_DEVICE_FLAG_INT_RX); 
```
result就是0
请问这个问题怎么修改呢

兜兜里有啥 2024-11-19

这家伙很懒，什么也没写！

heke 2024-11-20

这家伙很懒，什么也没写！

确实，在drv_usart.c中仿照BSP_USING_UART7  增加了UART8的DMA配置后可以了

```c
#ifdef BSP_USING_UART7
    uart_obj[UART7_INDEX].uart_dma_flag = 0;
#ifdef BSP_UART7_RX_USING_DMA
    uart_obj[UART7_INDEX].uart_dma_flag |= RT_DEVICE_FLAG_DMA_RX;
    static struct dma_config uart7_dma_rx = UART7_DMA_RX_CONFIG;
    uart_config[UART7_INDEX].dma_rx = &uart7_dma_rx;
#endif
#ifdef BSP_UART7_TX_USING_DMA
    uart_obj[UART7_INDEX].uart_dma_flag |= RT_DEVICE_FLAG_DMA_TX;
    static struct dma_config uart7_dma_tx = UART7_DMA_TX_CONFIG;
    uart_config[UART7_INDEX].dma_tx = &uart7_dma_tx;
#endif
#endif

#ifdef BSP_USING_UART8
    uart_obj[UART8_INDEX].uart_dma_flag = 0;
#ifdef BSP_UART8_RX_USING_DMA
    uart_obj[UART8_INDEX].uart_dma_flag |= RT_DEVICE_FLAG_DMA_RX;
    static struct dma_config uart8_dma_rx = UART8_DMA_RX_CONFIG;
    uart_config[UART8_INDEX].dma_rx = &uart8_dma_rx;
#endif
#ifdef BSP_UART7_TX_USING_DMA
    uart_obj[UART7_INDEX].uart_dma_flag |= RT_DEVICE_FLAG_DMA_TX;
    static struct dma_config uart7_dma_tx = UART7_DMA_TX_CONFIG;
    uart_config[UART7_INDEX].dma_tx = &uart7_dma_tx;
#endif
#endif
```