Merge pull request #2462 from svastm/serial_asynch_f2

[STM32F2] Add asynchronous serial

Author: sg-

hal/targets.json

@@ -702,7 +702,7 @@
         "inherits": ["Target"],
         "progen": {"target": "nucleo-f207zg"},
         "detect_code": ["0835"],
-        "device_has": ["ANALOGIN", "ANALOGOUT", "CAN", "I2C", "I2CSLAVE", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES"],
+        "device_has": ["ANALOGIN", "ANALOGOUT", "CAN", "I2C", "I2CSLAVE", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_ASYNCH", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES"],
         "features": ["IPV4"],
         "release_versions": ["2"]
     },

hal/targets/hal/TARGET_STM/TARGET_STM32F2/objects.h

@@ -74,6 +74,14 @@ struct serial_s {
     uint32_t parity;
     PinName pin_tx;
     PinName pin_rx;
+#if DEVICE_SERIAL_ASYNCH
+    uint32_t events;
+#endif
+#if DEVICE_SERIAL_FC
+    uint32_t hw_flow_ctl;
+    PinName pin_rts;
+    PinName pin_cts;
+#endif
 };
 
 struct spi_s {