*** EFM32 branch ***

Fix the bug in USART write, which is introduced by changing SPI write format

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1884 bbd45198-f89e-11dd-88c7-29a3b14d5316

bsp/efm32/drv_usart.c

@@ -505,7 +505,7 @@ static rt_size_t rt_usart_read (
                 while (!(usart_device->STATUS & rx_flag));
                 *((rt_uint32_t *)0x00) = usart_device->RXDATA;
             }
-
+            /* Read data */
             while (((rt_uint32_t)ptr - (rt_uint32_t)rx_buf) < size)
             {
                 /* dummy write */
@@ -575,9 +575,7 @@ static rt_size_t rt_usart_write (
     rt_err_t err_code;
     rt_size_t write_size = 0;
     struct efm32_usart_device_t* usart = (struct efm32_usart_device_t*)(dev->user_data);
-    rt_uint8_t inst_len     = *((rt_uint8_t *)buffer);
-    rt_uint8_t *inst_ptr    = (rt_uint8_t *)(buffer + 1);
-    rt_uint8_t *tx_buf      = *((rt_uint8_t **)(buffer + inst_len + 1));
+    rt_uint8_t *tx_buf;
     rt_uint32_t tx_flag, b8_flag;
 
 #if defined(UART_PRESENT)
@@ -608,15 +606,11 @@ static rt_size_t rt_usart_write (
         return 0;
     }
 
-    if (dev->flag & RT_DEVICE_FLAG_STREAM)
-    {
-        if (*(tx_buf + size - 1) == '\n')
-        {
-            *(tx_buf + size - 1) = '\r';
-            *(tx_buf + size++) = '\n';
-            *(tx_buf + size) = 0;
-        }
-    }
+    if (usart->state & USART_STATE_SYNC)
+    {   /* SPI write */
+        rt_uint8_t inst_len     = *((rt_uint8_t *)buffer);
+        rt_uint8_t *inst_ptr    = (rt_uint8_t *)(buffer + 1);
+        tx_buf = *((rt_uint8_t **)(buffer + inst_len + 1));
 
         /* Write instructions */
         if (inst_len)
@@ -674,8 +668,22 @@ static rt_size_t rt_usart_write (
                 usart->usart_device->CTRL |= b8_flag;
             }
         }
+    }
+    else
+    {
+        tx_buf = (rt_uint8_t *)buffer;
+    }
 
     /* Write data */
+    if (dev->flag & RT_DEVICE_FLAG_STREAM)
+    {
+        if (*(tx_buf + size - 1) == '\n')
+        {
+            *(tx_buf + size - 1) = '\r';
+            *(tx_buf + size++) = '\n';
+            *(tx_buf + size) = 0;
+        }
+    }
     if ((dev->flag & RT_DEVICE_FLAG_DMA_TX) && (size > 2))
     {   /* DMA mode Tx */
         struct efm32_usart_dma_mode_t *dma_tx;