add serial DMA transmit function(beta)

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2382 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/drivers/include/drivers/serial.h

@@ -57,18 +57,21 @@
 #define RT_SERIAL_ERR_OVERRUN           0x01
 #define RT_SERIAL_ERR_FRAMING           0x02
 #define RT_SERIAL_ERR_PARITY            0x03
+
+#define RT_SERIAL_TX_DATAQUEUE_SIZE     40
+#define RT_SERIAL_TX_DATAQUEUE_LWM      30
 
 /* Default config for serial_configure structure */
 #define RT_SERIAL_CONFIG_DEFAULT           \
 {                                          \
     BAUD_RATE_115200, /* 115200 bits/s */  \
     DATA_BITS_8,      /* 8 databits */     \
-	STOP_BITS_1,      /* 1 stopbit */      \
-	PARITY_NONE,      /* No parity  */     \
-	BIT_ORDER_LSB,    /* LSB first sent */ \
-	NRZ_NORMAL,       /* Normal mode */    \
-	0                                      \
-}                                                                                 
+    STOP_BITS_1,      /* 1 stopbit */      \
+    PARITY_NONE,      /* No parity  */     \
+    BIT_ORDER_LSB,    /* LSB first sent */ \
+    NRZ_NORMAL,       /* Normal mode */    \
+    0                                      \
+}
 
 struct serial_ringbuffer
 {
@@ -98,6 +101,10 @@ struct rt_serial_device
     struct serial_ringbuffer *int_rx;
     /* tx structure */
     struct serial_ringbuffer *int_tx;
+
+    struct rt_data_queue      tx_dq;              /* tx dataqueue */
+    
+    volatile rt_bool_t        dma_flag;           /* dma transfer flag */
 };
 typedef struct rt_serial_device rt_serial_t;
 
@@ -111,9 +118,12 @@ struct rt_uart_ops
 
     int (*putc)(struct rt_serial_device *serial, char c);
     int (*getc)(struct rt_serial_device *serial);
+
+    rt_size_t (*dma_transmit)(struct rt_serial_device *serial, const char *buf, rt_size_t size);
 };
 
 void rt_hw_serial_isr(struct rt_serial_device *serial);
+void rt_hw_serial_dma_tx_isr(struct rt_serial_device *serial);
 rt_err_t rt_hw_serial_register(struct rt_serial_device *serial,
                                const char              *name,
                                rt_uint32_t              flag,

components/drivers/include/rtdevice.h

@@ -125,15 +125,15 @@ rt_err_t rt_data_queue_init(struct rt_data_queue *queue,
                             rt_uint16_t           lwm,
                             void (*evt_notify)(struct rt_data_queue *queue, rt_uint32_t event));
 rt_err_t rt_data_queue_push(struct rt_data_queue *queue,
-                            void                 *data_ptr,
+                            const void           *data_ptr,
                             rt_size_t             data_size,
                             rt_int32_t            timeout);
 rt_err_t rt_data_queue_pop(struct rt_data_queue *queue,
-                           void                **data_ptr,
+                           const void          **data_ptr,
                            rt_size_t            *size,
                            rt_int32_t            timeout);
 rt_err_t rt_data_queue_peak(struct rt_data_queue *queue,
-                            void                **data_ptr,
+                            const void          **data_ptr,
                             rt_size_t            *size);
 void rt_data_queue_reset(struct rt_data_queue *queue);
 

components/drivers/serial/serial.c

@@ -132,7 +132,16 @@ static rt_err_t rt_serial_init(struct rt_device *dev)
             serial_ringbuffer_init(serial->int_rx);
 
         if (dev->flag & RT_DEVICE_FLAG_INT_TX)
-            serial_ringbuffer_init(serial->int_tx);      
+            serial_ringbuffer_init(serial->int_tx);
+
+        if (dev->flag & RT_DEVICE_FLAG_DMA_TX)
+        {
+            serial->dma_flag = RT_FALSE;
+            
+            /* init data queue */
+            rt_data_queue_init(&(serial->tx_dq), RT_SERIAL_TX_DATAQUEUE_SIZE,
+                               RT_SERIAL_TX_DATAQUEUE_LWM, RT_NULL);
+        }
 
         /* set activated */
         dev->flag |= RT_DEVICE_FLAG_ACTIVATED;
@@ -261,6 +270,41 @@ static rt_size_t rt_serial_write(struct rt_device *dev,
                 break;
         }
     }
+    else if (dev->flag & RT_DEVICE_FLAG_DMA_TX)
+    {
+        const void *data_ptr = RT_NULL;
+        rt_size_t data_size = 0;
+        rt_base_t level;
+        rt_err_t result;
+        
+        RT_ASSERT(0 == (dev->flag & RT_DEVICE_FLAG_STREAM));
+
+        result = rt_data_queue_push(&(serial->tx_dq), buffer, size, 20); 
+        if (result == RT_EOK)
+        {
+            level = rt_hw_interrupt_disable();
+            if (serial->dma_flag == RT_FALSE)
+            {
+                serial->dma_flag = RT_TRUE;
+                rt_hw_interrupt_enable(level);
+            
+                if (RT_EOK == rt_data_queue_pop(&(serial->tx_dq), &data_ptr, &data_size, 0))
+                {
+                    serial->ops->dma_transmit(serial, data_ptr, data_size);
+                }
+            }
+            else
+                rt_hw_interrupt_enable(level);
+
+            return size;
+        }
+        else
+        {
+            rt_set_errno(result);
+
+            return 0;
+        }
+    }
     else
     {
         /* polling mode */
@@ -377,3 +421,22 @@ void rt_hw_serial_isr(struct rt_serial_device *serial)
         serial->parent.rx_indicate(&serial->parent, rx_length);
     }
 }
+
+/*
+ * ISR for DMA mode Tx
+ */
+void rt_hw_serial_dma_tx_isr(struct rt_serial_device *serial)
+{
+    void *data_ptr;
+    rt_size_t data_size;
+
+    if (RT_EOK == rt_data_queue_pop(&(serial->tx_dq), &data_ptr, &data_size, 0))
+    {
+        /* transmit next data node */
+        serial->ops->dma_transmit(serial, data_ptr, data_size);
+    }
+    else
+    {
+        serial->dma_flag = RT_FALSE;
+    }
+}