px4fmu-v5:Support RX TX swap

src/drivers/boards/px4fmu-v5/board_config.h

@@ -521,7 +521,10 @@
 
 #define RC_UXART_BASE                      STM32_USART6_BASE
 #define RC_SERIAL_PORT                     "/dev/ttyS4"
-#define RC_SERIAL_PORT_IS_FULL_DUPLEX      false
+#define BOARD_HAS_SINGLE_WIRE              1 /* HW is capable of Single Wire */
+#define BOARD_HAS_SINGLE_WIRE_ON_TX        1 /* HW default is wired as Single Wire On TX pin */
+#define BOARD_HAS_RX_TX_SWAP               1 /* HW Can swap TX and RX */
+#define RC_SERIAL_PORT_IS_SWAPED           0 /* Board wired with RC's TX is on cpu RX */
 
 #define GPS_DEFAULT_UART_PORT "/dev/ttyS0" /* UART1 on FMUv5 */
 

src/drivers/boards/px4fmu-v5/init.c

@@ -130,7 +130,14 @@ __EXPORT void board_rc_input(bool invert_on, uint32_t uxart_base)
 	putreg32(regval, STM32_USART_CR1_OFFSET + uxart_base);
 
 	if (invert_on) {
+#if defined(BOARD_HAS_RX_TX_SWAP) &&	RC_SERIAL_PORT_IS_SWAPED == 1
+
+		/* This is only tuned on */
+
+		cr2 |= (USART_CR2_RXINV | USART_CR2_TXINV | USART_CR2_SWAP);
+#else
 		cr2 |= (USART_CR2_RXINV | USART_CR2_TXINV);
+#endif
 
 	} else {
 		cr2 &= ~(USART_CR2_RXINV | USART_CR2_TXINV);