Enable flow control in Greentea

Flow control is enabled in Greentea for targets that has
console-uart-flow-control set.

Author: Marcus Chang

features/frameworks/greentea-client/source/greentea_serial.cpp

@@ -1,5 +1,23 @@
 #include "greentea-client/greentea_serial.h"
 
+/**
+ * Macros for setting console flow control.
+ */
+#define CONSOLE_FLOWCONTROL_RTS     1
+#define CONSOLE_FLOWCONTROL_CTS     2
+#define CONSOLE_FLOWCONTROL_RTSCTS  3
+#define mbed_console_concat_(x) CONSOLE_FLOWCONTROL_##x
+#define mbed_console_concat(x) mbed_console_concat_(x)
+#define CONSOLE_FLOWCONTROL mbed_console_concat(MBED_CONF_TARGET_CONSOLE_UART_FLOW_CONTROL)
+
 SingletonPtr<GreenteaSerial> greentea_serial;
 
-GreenteaSerial::GreenteaSerial() : mbed::RawSerial(USBTX, USBRX, MBED_CONF_PLATFORM_STDIO_BAUD_RATE) {};
+GreenteaSerial::GreenteaSerial() : mbed::RawSerial(USBTX, USBRX, MBED_CONF_PLATFORM_STDIO_BAUD_RATE) {
+#if   CONSOLE_FLOWCONTROL == CONSOLE_FLOWCONTROL_RTS
+    set_flow_control(SerialBase::RTS, STDIO_UART_RTS, NC);
+#elif CONSOLE_FLOWCONTROL == CONSOLE_FLOWCONTROL_CTS
+    set_flow_control(SerialBase::CTS, NC, STDIO_UART_CTS);
+#elif CONSOLE_FLOWCONTROL == CONSOLE_FLOWCONTROL_RTSCTS
+    set_flow_control(SerialBase::RTSCTS, STDIO_UART_RTS, STDIO_UART_CTS);
+#endif
+}