[DeviceDriver][serial]

1.Fix poll rx issue when data is full.
2.Add TCFLSH and FIONREAD support.

components/drivers/serial/serial.c

@@ -33,6 +33,8 @@
  * 2016-05-10     armink       add fifo mode to DMA rx when serial->config.bufsz != 0.
  * 2017-01-19     aubr.cool    prevent change serial rx bufsz when serial is opened.
  * 2017-11-07     JasonJia     fix data bits error issue when using tcsetattr.
+ * 2017-11-15     JasonJia     fix poll rx issue when data is full.
+ *                             add TCFLSH and FIONREAD support.
  */
 
 #include <rthw.h>
@@ -191,7 +193,7 @@ static int serial_fops_poll(struct dfs_fd *fd, struct rt_pollreq *req)
         rx_fifo = (struct rt_serial_rx_fifo*) serial->serial_rx;
 
         level = rt_hw_interrupt_disable();
-        if (rx_fifo->get_index != rx_fifo->put_index)
+        if ((rx_fifo->get_index != rx_fifo->put_index) || (rx_fifo->get_index == rx_fifo->put_index && rx_fifo->is_full == RT_TRUE))
             mask |= POLLIN;
         rt_hw_interrupt_enable(level);
     }
@@ -286,19 +288,25 @@ rt_inline int _serial_int_rx(struct rt_serial_device *serial, rt_uint8_t *data,
 
         /* disable interrupt */
         level = rt_hw_interrupt_disable();
-        if (rx_fifo->get_index != rx_fifo->put_index)
+
-        {
+        /* there's no data: */
-            ch = rx_fifo->buffer[rx_fifo->get_index];
+        if ((rx_fifo->get_index == rx_fifo->put_index) && (rx_fifo->is_full == RT_FALSE))
-            rx_fifo->get_index += 1;
-            if (rx_fifo->get_index >= serial->config.bufsz) rx_fifo->get_index = 0;
-        }
-        else
         {
             /* no data, enable interrupt and break out */
             rt_hw_interrupt_enable(level);
             break;
         }
 
+        /* otherwise there's the data: */
+        ch = rx_fifo->buffer[rx_fifo->get_index];
+        rx_fifo->get_index += 1;
+        if (rx_fifo->get_index >= serial->config.bufsz) rx_fifo->get_index = 0;
+
+        if (rx_fifo->is_full == RT_TRUE)
+        {
+            rx_fifo->is_full = RT_FALSE;
+        }
+
         /* enable interrupt */
         rt_hw_interrupt_enable(level);
 
@@ -334,6 +342,71 @@ rt_inline int _serial_int_tx(struct rt_serial_device *serial, const rt_uint8_t *
     return size - length;
 }
 
+static rt_size_t _serial_fifo_calc_recved_len(struct rt_serial_device *serial)
+{
+    struct rt_serial_rx_fifo *rx_fifo = (struct rt_serial_rx_fifo *) serial->serial_rx;
+
+    RT_ASSERT(rx_fifo != RT_NULL);
+
+    if (rx_fifo->put_index == rx_fifo->get_index)
+    {
+        return (rx_fifo->is_full == RT_FALSE ? 0 : serial->config.bufsz);
+    }
+    else
+    {
+        if (rx_fifo->put_index > rx_fifo->get_index)
+        {
+            return rx_fifo->put_index - rx_fifo->get_index;
+        }
+        else
+        {
+            return serial->config.bufsz - (rx_fifo->get_index - rx_fifo->put_index);
+        }
+    }
+}
+
+static void _serial_flush(struct rt_serial_device *serial, int queue)
+{
+    int ch = -1;
+    struct rt_serial_rx_fifo *rx_fifo = RT_NULL;
+    struct rt_device *device = RT_NULL;
+
+    RT_ASSERT(serial != RT_NULL);
+
+    device = &(serial->parent);
+    rx_fifo = (struct rt_serial_rx_fifo *) serial->serial_rx;
+
+    switch(queue)
+    {
+        case TCIFLUSH:
+        case TCIOFLUSH:
+
+            RT_ASSERT(rx_fifo != RT_NULL);
+
+            if((device->open_flag & RT_DEVICE_FLAG_INT_RX) || (device->open_flag & RT_DEVICE_FLAG_DMA_RX))
+            {
+                RT_ASSERT(RT_NULL != rx_fifo);
+                rt_memset(rx_fifo->buffer, 0, serial->config.bufsz);
+                rx_fifo->put_index = 0;
+                rx_fifo->get_index = 0;
+                rx_fifo->is_full = RT_FALSE;
+            }
+            else
+            {
+                while (1)
+                {
+                    ch = serial->ops->getc(serial);
+                    if (ch == -1) break;
+                }
+            }
+
+            break;
+
+         case TCOFLUSH:
+            break;
+    }
+
+}
 /**
  * Calculate DMA received data length.
  *
@@ -343,25 +416,11 @@ rt_inline int _serial_int_tx(struct rt_serial_device *serial, const rt_uint8_t *
  */
 static rt_size_t rt_dma_calc_recved_len(struct rt_serial_device *serial)
 {
-    struct rt_serial_rx_fifo *rx_fifo = (struct rt_serial_rx_fifo *) serial->serial_rx;
+    return _serial_fifo_calc_recved_len(serial);
-
-    RT_ASSERT(rx_fifo != RT_NULL);
-
-    if (rx_fifo->put_index > rx_fifo->get_index)
-        return rx_fifo->put_index - rx_fifo->get_index;
-    else if (rx_fifo->put_index < rx_fifo->get_index)
-        return serial->config.bufsz - (rx_fifo->get_index - rx_fifo->put_index);
-    else
-    {
-        if (rx_fifo->is_full)
-            return serial->config.bufsz;
-        else
-            return 0;
-    }
 }
 
 /**
- * Read data finish by DMA mode then update the gut index for receive fifo.
+ * Read data finish by DMA mode then update the get index for receive fifo.
  *
  * @param serial serial device
  * @param len get data length for this operate
@@ -612,6 +671,7 @@ static rt_err_t rt_serial_open(struct rt_device *dev, rt_uint16_t oflag)
             rt_memset(rx_fifo->buffer, 0, serial->config.bufsz);
             rx_fifo->put_index = 0;
             rx_fifo->get_index = 0;
+            rx_fifo->is_full = RT_FALSE;
 
             serial->serial_rx = rx_fifo;
             dev->open_flag |= RT_DEVICE_FLAG_INT_RX;
@@ -963,11 +1023,30 @@ static rt_err_t rt_serial_control(struct rt_device *dev,
             }
             break;
         case TCFLSH:
+            {
+                int queue = *(int *)args;
+
+                _serial_flush(serial, queue);
+            }
+
             break;
         case TCXONC:
             break;
 #endif
+#ifdef RT_USING_POSIX
+        case FIONREAD:
+            {
+                rt_size_t recved = 0;
+                rt_base_t level;
 
+                level = rt_hw_interrupt_disable();
+                recved = _serial_fifo_calc_recved_len(serial);
+                rt_hw_interrupt_enable(level);
+
+                *(rt_size_t *)args = recved;
+            }
+            break;
+#endif
         default :
             /* control device */
             ret = serial->ops->control(serial, cmd, args);
@@ -1046,6 +1125,7 @@ void rt_hw_serial_isr(struct rt_serial_device *serial, int event)
                 if (rx_fifo->put_index == rx_fifo->get_index)
                 {
                     rx_fifo->get_index += 1;
+                    rx_fifo->is_full = RT_TRUE;
                     if (rx_fifo->get_index >= serial->config.bufsz) rx_fifo->get_index = 0;
                 }