uart: add tcsendbreak support

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Alex Tereschenko <alext.mkrs@gmail.com>

api/mraa/uart.h

@@ -72,6 +72,18 @@ mraa_uart_context mraa_uart_init_raw(const char* path);
  */
 mraa_result_t mraa_uart_flush(mraa_uart_context dev);
 
+/**
+ * Send a break to the device.
+ * Blocks until complete.
+ *
+ * @param dev The UART context
+ * @param duration When 0, send a break lasting at least 250
+ * milliseconds, and not more than 500 milliseconds.  When non zero,
+ * the break duration is implementation specific.
+ * @return Result of operation
+ */
+mraa_result_t mraa_uart_sendbreak(mraa_uart_context dev, int duration);
+
 /**
  * Set the baudrate.
  * Takes an int and will attempt to decide what baudrate  is

api/mraa/uart.hpp

@@ -197,6 +197,21 @@ class Uart
         return (Result) mraa_uart_flush(m_uart);
     }
 
+    /**
+     * Send a break to the device.
+     * Blocks until complete.
+     *
+     * @param duration When 0, send a break lasting at least 250
+     * milliseconds, and not more than 500 milliseconds.  When non zero,
+     * the break duration is implementation specific.
+     * @return Result of operation
+     */
+    Result
+    sendBreak(int duration)
+    {
+        return (Result) mraa_uart_sendbreak(m_uart, duration);
+    }
+
     /**
      * Set the baudrate.
      * Takes an int and will attempt to decide what baudrate  is