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[BSP] Add usart DMA Rx driver to stm32f10x.

armink 9 years ago
parent
commit
7d17f50a31
1 changed files with 226 additions and 90 deletions
  1. 226 90
      bsp/stm32f10x/drivers/usart.c

+ 226 - 90
bsp/stm32f10x/drivers/usart.c

@@ -13,6 +13,7 @@
  * 2010-03-29     Bernard      remove interrupt Tx and DMA Rx mode
  * 2010-03-29     Bernard      remove interrupt Tx and DMA Rx mode
  * 2013-05-13     aozima       update for kehong-lingtai.
  * 2013-05-13     aozima       update for kehong-lingtai.
  * 2015-01-31     armink       make sure the serial transmit complete in putc()
  * 2015-01-31     armink       make sure the serial transmit complete in putc()
+ * 2016-05-13     armink       add DMA Rx mode
  */
  */
 
 
 #include "stm32f10x.h"
 #include "stm32f10x.h"
@@ -44,10 +45,22 @@
 /* STM32 uart driver */
 /* STM32 uart driver */
 struct stm32_uart
 struct stm32_uart
 {
 {
-    USART_TypeDef* uart_device;
+    USART_TypeDef *uart_device;
     IRQn_Type irq;
     IRQn_Type irq;
+    struct stm32_uart_dma {
+        /* dma channel */
+        DMA_Channel_TypeDef *rx_ch;
+        /* dma global flag */
+        uint32_t rx_gl_flag;
+        /* dma irq channel */
+        uint8_t rx_irq_ch;
+        /* last receive index */
+        rt_size_t last_recv_len;
+    } dma;
 };
 };
 
 
+static void DMA_Configuration(struct rt_serial_device *serial);
+
 static rt_err_t stm32_configure(struct rt_serial_device *serial, struct serial_configure *cfg)
 static rt_err_t stm32_configure(struct rt_serial_device *serial, struct serial_configure *cfg)
 {
 {
     struct stm32_uart* uart;
     struct stm32_uart* uart;
@@ -93,6 +106,7 @@ static rt_err_t stm32_configure(struct rt_serial_device *serial, struct serial_c
 static rt_err_t stm32_control(struct rt_serial_device *serial, int cmd, void *arg)
 static rt_err_t stm32_control(struct rt_serial_device *serial, int cmd, void *arg)
 {
 {
     struct stm32_uart* uart;
     struct stm32_uart* uart;
+    rt_uint32_t ctrl_arg = (rt_uint32_t)(arg);
 
 
     RT_ASSERT(serial != RT_NULL);
     RT_ASSERT(serial != RT_NULL);
     uart = (struct stm32_uart *)serial->parent.user_data;
     uart = (struct stm32_uart *)serial->parent.user_data;
@@ -113,8 +127,13 @@ static rt_err_t stm32_control(struct rt_serial_device *serial, int cmd, void *ar
         /* enable interrupt */
         /* enable interrupt */
         USART_ITConfig(uart->uart_device, USART_IT_RXNE, ENABLE);
         USART_ITConfig(uart->uart_device, USART_IT_RXNE, ENABLE);
         break;
         break;
+        /* USART config */
+    case RT_DEVICE_CTRL_CONFIG :
+        if (ctrl_arg == RT_DEVICE_FLAG_DMA_RX) {
+            DMA_Configuration(serial);
+        }
+        break;
     }
     }
-
     return RT_EOK;
     return RT_EOK;
 }
 }
 
 
@@ -148,6 +167,91 @@ static int stm32_getc(struct rt_serial_device *serial)
     return ch;
     return ch;
 }
 }
 
 
+/**
+ * Serial port receive idle process. This need add to uart idle ISR.
+ *
+ * @param serial serial device
+ */
+static void dma_uart_rx_idle_isr(struct rt_serial_device *serial) {
+    struct stm32_uart *uart = (struct stm32_uart *) serial->parent.user_data;
+    rt_size_t recv_total_len, recv_len;
+    /* disable dma, stop receive data */
+    DMA_Cmd(uart->dma.rx_ch, DISABLE);
+
+    recv_total_len = serial->config.bufsz - DMA_GetCurrDataCounter(uart->dma.rx_ch);
+    if (recv_total_len > uart->dma.last_recv_len) {
+        recv_len = recv_total_len - uart->dma.last_recv_len;
+    } else {
+        recv_len = recv_total_len;
+    }
+    uart->dma.last_recv_len = recv_total_len;
+
+    rt_hw_serial_isr(serial, RT_SERIAL_EVENT_RX_DMADONE | (recv_len << 8));
+
+    /* read a data for clear receive idle interrupt flag */
+    USART_ReceiveData(uart->uart_device);
+    DMA_ClearFlag(uart->dma.rx_gl_flag);
+    DMA_Cmd(uart->dma.rx_ch, ENABLE);
+}
+
+/**
+ * DMA receive done process. This need add to DMA receive done ISR.
+ *
+ * @param serial serial device
+ */
+static void dma_rx_done_isr(struct rt_serial_device *serial) {
+    struct stm32_uart *uart = (struct stm32_uart *) serial->parent.user_data;
+    rt_size_t recv_total_len, recv_len;
+    /* disable dma, stop receive data */
+    DMA_Cmd(uart->dma.rx_ch, DISABLE);
+
+    recv_total_len = serial->config.bufsz - DMA_GetCurrDataCounter(uart->dma.rx_ch);
+    if (recv_total_len > uart->dma.last_recv_len) {
+        recv_len = recv_total_len - uart->dma.last_recv_len;
+    } else {
+        recv_len = recv_total_len;
+    }
+    uart->dma.last_recv_len = recv_total_len;
+
+    rt_hw_serial_isr(serial, RT_SERIAL_EVENT_RX_DMADONE | (recv_len << 8));
+
+    DMA_ClearFlag(uart->dma.rx_gl_flag);
+    /* reload */
+    DMA_SetCurrDataCounter(uart->dma.rx_ch, serial->config.bufsz);
+    DMA_Cmd(uart->dma.rx_ch, ENABLE);
+}
+
+/**
+ * Uart common interrupt process. This need add to uart ISR.
+ *
+ * @param serial serial device
+ */
+static void uart_isr(struct rt_serial_device *serial) {
+    struct stm32_uart *uart = (struct stm32_uart *) serial->parent.user_data;
+
+    RT_ASSERT(uart != RT_NULL);
+
+    if(USART_GetITStatus(uart->uart_device, USART_IT_RXNE) != RESET)
+    {
+        rt_hw_serial_isr(serial, RT_SERIAL_EVENT_RX_IND);
+        /* clear interrupt */
+        USART_ClearITPendingBit(uart->uart_device, USART_IT_RXNE);
+    }
+    if(USART_GetITStatus(uart->uart_device, USART_IT_IDLE) != RESET)
+    {
+        dma_uart_rx_idle_isr(serial);
+    }
+    if (USART_GetITStatus(uart->uart_device, USART_IT_TC) != RESET)
+    {
+        /* clear interrupt */
+        USART_ClearITPendingBit(uart->uart_device, USART_IT_TC);
+    }
+    if (USART_GetFlagStatus(uart->uart_device, USART_FLAG_ORE) == SET)
+    {
+        stm32_getc(serial);
+    }
+}
+
 static const struct rt_uart_ops stm32_uart_ops =
 static const struct rt_uart_ops stm32_uart_ops =
 {
 {
     stm32_configure,
     stm32_configure,
@@ -162,70 +266,68 @@ struct stm32_uart uart1 =
 {
 {
     USART1,
     USART1,
     USART1_IRQn,
     USART1_IRQn,
+    {
+        DMA1_Channel5,
+        DMA1_FLAG_GL5,
+        DMA1_Channel5_IRQn,
+        0,
+    },
 };
 };
 struct rt_serial_device serial1;
 struct rt_serial_device serial1;
 
 
 void USART1_IRQHandler(void)
 void USART1_IRQHandler(void)
 {
 {
-    struct stm32_uart* uart;
+    /* enter interrupt */
+    rt_interrupt_enter();
 
 
-    uart = &uart1;
+    uart_isr(&serial1);
+
+    /* leave interrupt */
+    rt_interrupt_leave();
+}
 
 
+void DMA1_Channel5_IRQHandler(void) {
     /* enter interrupt */
     /* enter interrupt */
     rt_interrupt_enter();
     rt_interrupt_enter();
-    if(USART_GetITStatus(uart->uart_device, USART_IT_RXNE) != RESET)
-    {
-        rt_hw_serial_isr(&serial1, RT_SERIAL_EVENT_RX_IND);
-        /* clear interrupt */
-        USART_ClearITPendingBit(uart->uart_device, USART_IT_RXNE);
-    }
 
 
-    if (USART_GetITStatus(uart->uart_device, USART_IT_TC) != RESET)
-    {
-        /* clear interrupt */
-        USART_ClearITPendingBit(uart->uart_device, USART_IT_TC);
-    }
-    if (USART_GetFlagStatus(uart->uart_device, USART_FLAG_ORE) == SET)
-    {
-        stm32_getc(&serial1);
-    }
+    dma_rx_done_isr(&serial1);
+
     /* leave interrupt */
     /* leave interrupt */
     rt_interrupt_leave();
     rt_interrupt_leave();
 }
 }
 #endif /* RT_USING_UART1 */
 #endif /* RT_USING_UART1 */
 
 
 #if defined(RT_USING_UART2)
 #if defined(RT_USING_UART2)
-/* UART1 device driver structure */
+/* UART2 device driver structure */
 struct stm32_uart uart2 =
 struct stm32_uart uart2 =
 {
 {
     USART2,
     USART2,
     USART2_IRQn,
     USART2_IRQn,
+    {
+        DMA1_Channel6,
+        DMA1_FLAG_GL6,
+        DMA1_Channel6_IRQn,
+        0,
+    },
 };
 };
 struct rt_serial_device serial2;
 struct rt_serial_device serial2;
 
 
 void USART2_IRQHandler(void)
 void USART2_IRQHandler(void)
 {
 {
-    struct stm32_uart* uart;
+    /* enter interrupt */
+    rt_interrupt_enter();
 
 
-    uart = &uart2;
+    uart_isr(&serial2);
 
 
+    /* leave interrupt */
+    rt_interrupt_leave();
+}
+
+void DMA1_Channel6_IRQHandler(void) {
     /* enter interrupt */
     /* enter interrupt */
     rt_interrupt_enter();
     rt_interrupt_enter();
-    if(USART_GetITStatus(uart->uart_device, USART_IT_RXNE) != RESET)
-    {
-        rt_hw_serial_isr(&serial2, RT_SERIAL_EVENT_RX_IND);
-        /* clear interrupt */
-        USART_ClearITPendingBit(uart->uart_device, USART_IT_RXNE);
-    }
-    if (USART_GetITStatus(uart->uart_device, USART_IT_TC) != RESET)
-    {
-        /* clear interrupt */
-        USART_ClearITPendingBit(uart->uart_device, USART_IT_TC);
-    }
-    if (USART_GetFlagStatus(uart->uart_device, USART_FLAG_ORE) == SET)
-    {
-        stm32_getc(&serial2);
-    }
+
+    dma_rx_done_isr(&serial2);
 
 
     /* leave interrupt */
     /* leave interrupt */
     rt_interrupt_leave();
     rt_interrupt_leave();
@@ -238,32 +340,31 @@ struct stm32_uart uart3 =
 {
 {
     USART3,
     USART3,
     USART3_IRQn,
     USART3_IRQn,
+    {
+        DMA1_Channel3,
+        DMA1_FLAG_GL3,
+        DMA1_Channel3_IRQn,
+        0,
+    },
 };
 };
 struct rt_serial_device serial3;
 struct rt_serial_device serial3;
 
 
 void USART3_IRQHandler(void)
 void USART3_IRQHandler(void)
 {
 {
-    struct stm32_uart* uart;
+    /* enter interrupt */
+    rt_interrupt_enter();
 
 
-    uart = &uart3;
+    uart_isr(&serial3);
 
 
+    /* leave interrupt */
+    rt_interrupt_leave();
+}
+
+void DMA1_Channel3_IRQHandler(void) {
     /* enter interrupt */
     /* enter interrupt */
     rt_interrupt_enter();
     rt_interrupt_enter();
-    if(USART_GetITStatus(uart->uart_device, USART_IT_RXNE) != RESET)
-    {
-        rt_hw_serial_isr(&serial3, RT_SERIAL_EVENT_RX_IND);
-        /* clear interrupt */
-        USART_ClearITPendingBit(uart->uart_device, USART_IT_RXNE);
-    }
-    if (USART_GetITStatus(uart->uart_device, USART_IT_TC) != RESET)
-    {
-        /* clear interrupt */
-        USART_ClearITPendingBit(uart->uart_device, USART_IT_TC);
-    }
-    if (USART_GetFlagStatus(uart->uart_device, USART_FLAG_ORE) == SET)
-    {
-        stm32_getc(&serial3);
-    }
+
+    dma_rx_done_isr(&serial3);
 
 
     /* leave interrupt */
     /* leave interrupt */
     rt_interrupt_leave();
     rt_interrupt_leave();
@@ -276,69 +377,66 @@ struct stm32_uart uart4 =
 {
 {
     UART4,
     UART4,
     UART4_IRQn,
     UART4_IRQn,
+    {
+        DMA2_Channel3,
+        DMA2_FLAG_GL3,
+        DMA2_Channel3_IRQn,
+        0,
+    },
 };
 };
 struct rt_serial_device serial4;
 struct rt_serial_device serial4;
 
 
 void UART4_IRQHandler(void)
 void UART4_IRQHandler(void)
 {
 {
-    struct stm32_uart* uart;
+    /* enter interrupt */
+    rt_interrupt_enter();
 
 
-    uart = &uart4;
+    uart_isr(&serial4);
 
 
+    /* leave interrupt */
+    rt_interrupt_leave();
+}
+
+void DMA2_Channel3_IRQHandler(void) {
     /* enter interrupt */
     /* enter interrupt */
     rt_interrupt_enter();
     rt_interrupt_enter();
-    if(USART_GetITStatus(uart->uart_device, USART_IT_RXNE) != RESET)
-    {
-        rt_hw_serial_isr(&serial4, RT_SERIAL_EVENT_RX_IND);
-        /* clear interrupt */
-        USART_ClearITPendingBit(uart->uart_device, USART_IT_RXNE);
-    }
-    if (USART_GetITStatus(uart->uart_device, USART_IT_TC) != RESET)
-    {
-        /* clear interrupt */
-        USART_ClearITPendingBit(uart->uart_device, USART_IT_TC);
-    }
-    if (USART_GetFlagStatus(uart->uart_device, USART_FLAG_ORE) == SET)
-    {
-        stm32_getc(&serial4);
-    }
+
+    dma_rx_done_isr(&serial4);
 
 
     /* leave interrupt */
     /* leave interrupt */
     rt_interrupt_leave();
     rt_interrupt_leave();
 }
 }
-#endif /* RT_USING_UART3 */
-
+#endif /* RT_USING_UART4 */
 
 
 static void RCC_Configuration(void)
 static void RCC_Configuration(void)
 {
 {
 #if defined(RT_USING_UART1)
 #if defined(RT_USING_UART1)
     /* Enable UART GPIO clocks */
     /* Enable UART GPIO clocks */
-    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
+    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
     /* Enable UART clock */
     /* Enable UART clock */
     RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
     RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
 #endif /* RT_USING_UART1 */
 #endif /* RT_USING_UART1 */
 
 
 #if defined(RT_USING_UART2)
 #if defined(RT_USING_UART2)
     /* Enable UART GPIO clocks */
     /* Enable UART GPIO clocks */
-    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
+    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
     /* Enable UART clock */
     /* Enable UART clock */
     RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
     RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
 #endif /* RT_USING_UART2 */
 #endif /* RT_USING_UART2 */
 
 
 #if defined(RT_USING_UART3)
 #if defined(RT_USING_UART3)
     /* Enable UART GPIO clocks */
     /* Enable UART GPIO clocks */
-    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
+    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
     /* Enable UART clock */
     /* Enable UART clock */
     RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
     RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
 #endif /* RT_USING_UART3 */
 #endif /* RT_USING_UART3 */
 
 
 #if defined(RT_USING_UART4)
 #if defined(RT_USING_UART4)
     /* Enable UART GPIO clocks */
     /* Enable UART GPIO clocks */
-    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
+    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);
     /* Enable UART clock */
     /* Enable UART clock */
     RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4, ENABLE);
     RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4, ENABLE);
 #endif /* RT_USING_UART4 */
 #endif /* RT_USING_UART4 */
-
 }
 }
 
 
 static void GPIO_Configuration(void)
 static void GPIO_Configuration(void)
@@ -390,7 +488,6 @@ static void GPIO_Configuration(void)
     GPIO_InitStructure.GPIO_Pin = UART4_GPIO_TX;
     GPIO_InitStructure.GPIO_Pin = UART4_GPIO_TX;
     GPIO_Init(UART4_GPIO, &GPIO_InitStructure);
     GPIO_Init(UART4_GPIO, &GPIO_InitStructure);
 #endif /* RT_USING_UART4 */
 #endif /* RT_USING_UART4 */
-
 }
 }
 
 
 static void NVIC_Configuration(struct stm32_uart* uart)
 static void NVIC_Configuration(struct stm32_uart* uart)
@@ -405,6 +502,46 @@ static void NVIC_Configuration(struct stm32_uart* uart)
     NVIC_Init(&NVIC_InitStructure);
     NVIC_Init(&NVIC_InitStructure);
 }
 }
 
 
+static void DMA_Configuration(struct rt_serial_device *serial) {
+    struct stm32_uart *uart = (struct stm32_uart *) serial->parent.user_data;
+    struct rt_serial_rx_fifo *rx_fifo = (struct rt_serial_rx_fifo *)serial->serial_rx;
+    DMA_InitTypeDef DMA_InitStructure;
+    NVIC_InitTypeDef NVIC_InitStructure;
+
+    /* enable transmit idle interrupt */
+    USART_ITConfig(uart->uart_device, USART_IT_IDLE , ENABLE);
+
+    /* DMA clock enable */
+    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
+    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE);
+
+    /* rx dma config */
+    DMA_DeInit(uart->dma.rx_ch);
+    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&(uart->uart_device->DR);
+    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t) rx_fifo->buffer;
+    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
+    DMA_InitStructure.DMA_BufferSize = serial->config.bufsz;
+    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
+    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
+    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
+    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
+    DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
+    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
+    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
+    DMA_Init(uart->dma.rx_ch, &DMA_InitStructure);
+    DMA_ClearFlag(uart->dma.rx_gl_flag);
+    DMA_ITConfig(uart->dma.rx_ch, DMA_IT_TC, ENABLE);
+    USART_DMACmd(uart->uart_device, USART_DMAReq_Rx, ENABLE);
+    DMA_Cmd(uart->dma.rx_ch, ENABLE);
+
+    /* rx dma interrupt config */
+    NVIC_InitStructure.NVIC_IRQChannel = uart->dma.rx_irq_ch;
+    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
+    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
+    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
+    NVIC_Init(&NVIC_InitStructure);
+}
+
 void rt_hw_usart_init(void)
 void rt_hw_usart_init(void)
 {
 {
     struct stm32_uart* uart;
     struct stm32_uart* uart;
@@ -420,11 +557,11 @@ void rt_hw_usart_init(void)
     serial1.ops    = &stm32_uart_ops;
     serial1.ops    = &stm32_uart_ops;
     serial1.config = config;
     serial1.config = config;
 
 
-    NVIC_Configuration(&uart1);
+    NVIC_Configuration(uart);
 
 
     /* register UART1 device */
     /* register UART1 device */
     rt_hw_serial_register(&serial1, "uart1",
     rt_hw_serial_register(&serial1, "uart1",
-                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX ,
+                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX | RT_DEVICE_FLAG_DMA_RX,
                           uart);
                           uart);
 #endif /* RT_USING_UART1 */
 #endif /* RT_USING_UART1 */
 
 
@@ -435,11 +572,11 @@ void rt_hw_usart_init(void)
     serial2.ops    = &stm32_uart_ops;
     serial2.ops    = &stm32_uart_ops;
     serial2.config = config;
     serial2.config = config;
 
 
-    NVIC_Configuration(&uart2);
+    NVIC_Configuration(uart);
 
 
-    /* register UART1 device */
+    /* register UART2 device */
     rt_hw_serial_register(&serial2, "uart2",
     rt_hw_serial_register(&serial2, "uart2",
-                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
+                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX | RT_DEVICE_FLAG_DMA_RX,
                           uart);
                           uart);
 #endif /* RT_USING_UART2 */
 #endif /* RT_USING_UART2 */
 
 
@@ -451,11 +588,11 @@ void rt_hw_usart_init(void)
     serial3.ops    = &stm32_uart_ops;
     serial3.ops    = &stm32_uart_ops;
     serial3.config = config;
     serial3.config = config;
 
 
-    NVIC_Configuration(&uart3);
+    NVIC_Configuration(uart);
 
 
-    /* register UART1 device */
+    /* register UART3 device */
     rt_hw_serial_register(&serial3, "uart3",
     rt_hw_serial_register(&serial3, "uart3",
-                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
+                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX | RT_DEVICE_FLAG_DMA_RX,
                           uart);
                           uart);
 #endif /* RT_USING_UART3 */
 #endif /* RT_USING_UART3 */
 
 
@@ -467,12 +604,11 @@ void rt_hw_usart_init(void)
     serial4.ops    = &stm32_uart_ops;
     serial4.ops    = &stm32_uart_ops;
     serial4.config = config;
     serial4.config = config;
 
 
-    NVIC_Configuration(&uart4);
+    NVIC_Configuration(uart);
 
 
     /* register UART4 device */
     /* register UART4 device */
     rt_hw_serial_register(&serial4, "uart4",
     rt_hw_serial_register(&serial4, "uart4",
-                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
+                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX | RT_DEVICE_FLAG_DMA_RX,
                           uart);
                           uart);
 #endif /* RT_USING_UART4 */
 #endif /* RT_USING_UART4 */
-
 }
 }