[Generic Serial] Add SerialUSB

If USB CDC is enabled then the generic "Serial" used will be SerialUSB
else this is the HardwareSerial if one is defined.

If Serial is defined before (build_opt.h, variant.h)
then this is the one used.

ISO for generic "serialEvent".

Signed-off-by: Frederic.Pillon <frederic.pillon@st.com>

Author: fpistm

cores/arduino/USBSerial.cpp

@@ -37,6 +37,7 @@ extern __IO uint32_t UserRxBufPtrIn;
 extern __IO uint32_t UserRxBufPtrOut;
 
 USBSerial SerialUSB;
+void serialEventUSB() __attribute__((weak));
 
 void USBSerial::begin(uint32_t /* baud_count */) {
   // uart config is ignored in USB-CDC

cores/arduino/WSerial.cpp

@@ -35,5 +35,8 @@ void serialEventRun(void)
 #if defined(HAVE_HWSERIALLP1)
   if (serialEventLP1 && SerialLP1.available()) serialEventLP1();
 #endif
+#if defined(HAVE_SERIALUSB)
+  if (serialEventUSB && SerialUSB.available()) serialEventUSB();
+#endif
 }
 

cores/arduino/WSerial.h

@@ -3,9 +3,25 @@
 
 #include "variant.h"
 #include "HardwareSerial.h"
+#include "USBSerial.h"
 
-#if defined(HAL_UART_MODULE_ENABLED)
+#if defined (USBCON) && defined(USBD_USE_CDC)
+#ifndef DISABLE_GENERIC_SERIALUSB
+#define ENABLE_SERIALUSB
+#if !defined(Serial)
+#define Serial SerialUSB
+#define serialEvent serialEventUSB
+#endif
+#endif
+
+#if defined(ENABLE_SERIALUSB)
+#define HAVE_SERIALUSB
+#endif
+
+extern void serialEventUSB(void) __attribute__((weak));
+#endif /* USBCON && USBD_USE_CDC */
 
+#if defined(HAL_UART_MODULE_ENABLED)
 #if !defined(HWSERIAL_NONE) && defined(SERIAL_UART_INSTANCE)
 #if SERIAL_UART_INSTANCE == 0
 #define ENABLE_HWSERIALLP1
@@ -147,8 +163,8 @@ extern void serialEvent8(void) __attribute__((weak));
 extern void serialEvent9(void) __attribute__((weak));
 extern void serialEvent10(void) __attribute__((weak));
 extern void serialEventLP1(void) __attribute__((weak));
-
 #endif /* HAL_UART_MODULE_ENABLED */
+
 extern void serialEventRun(void) __attribute__((weak));
 
-#endif // WIRING_SERIAL_H
+#endif /* WIRING_SERIAL_H */

cores/arduino/wiring.h

@@ -42,7 +42,6 @@
 
 #ifdef __cplusplus
 #include "Tone.h"
-#include "USBSerial.h"
 #include "WCharacter.h"
 #include "WSerial.h"
 #include "WMath.h"