Handle USART TX pulldown (#12929)

SA is always unidirectional
Only switch AT32 TX line to input when transmission is complete

src/main/drivers/at32/serial_uart_at32bsp.c

@@ -93,7 +93,7 @@ void uartReconfigure(uartPort_t *uartPort)
     //init
     usart_init(uartPort->USARTx,
                uartPort->port.baudRate,
-              (uartPort->port.options & SERIAL_PARITY_EVEN)? USART_DATA_9BITS:USART_DATA_8BITS,
+               USART_DATA_8BITS,
               (uartPort->port.options & SERIAL_STOPBITS_2) ? USART_STOP_2_BIT : USART_STOP_1_BIT);
 
     //set parity
@@ -196,7 +196,7 @@ bool checkUsartTxOutput(uartPort_t *s)
 
             // Enable USART TX output
             uart->txPinState = TX_PIN_ACTIVE;
-            IOConfigGPIOAF(txIO, IOCFG_AF_PP, uart->hardware->af);
+            IOConfigGPIOAF(txIO, IOCFG_AF_PP, uart->tx.af);
             return true;
         } else {
             // TX line is pulled low so don't enable USART TX
@@ -210,11 +210,14 @@ bool checkUsartTxOutput(uartPort_t *s)
 void uartTxMonitor(uartPort_t *s)
 {
     uartDevice_t *uart = container_of(s, uartDevice_t, port);
-    IO_t txIO = IOGetByTag(uart->tx.pin);
 
-    // Switch TX to an input with pullup so it's state can be monitored
+    if (uart->txPinState == TX_PIN_ACTIVE) {
-    uart->txPinState = TX_PIN_MONITOR;
+        IO_t txIO = IOGetByTag(uart->tx.pin);
-    IOConfigGPIO(txIO, IOCFG_IPU);
+
+        // Switch TX to an input with pullup so it's state can be monitored
+        uart->txPinState = TX_PIN_MONITOR;
+        IOConfigGPIO(txIO, IOCFG_IPU);
+    }
 }
 
 #ifdef USE_DMA
@@ -263,11 +266,9 @@ void uartTryStartTxDMA(uartPort_t *s)
 
 static void handleUsartTxDma(uartPort_t *s)
 {
-    uartDevice_t *uart = container_of(s, uartDevice_t, port);
-
     uartTryStartTxDMA(s);
 
-    if (s->txDMAEmpty && (uart->txPinState != TX_PIN_IGNORE)) {
+    if (s->txDMAEmpty) {
         // Switch TX to an input with pullup so it's state can be monitored
         uartTxMonitor(s);
     }
@@ -314,9 +315,6 @@ void uartIrqHandler(uartPort_t *s)
             s->port.txBufferTail = (s->port.txBufferTail + 1) % s->port.txBufferSize;
         } else {
             usart_interrupt_enable(s->USARTx, USART_TDBE_INT, FALSE);
-
-            // Switch TX to an input with pullup so it's state can be monitored
-            uartTxMonitor(s);
         }
     }
 

src/main/drivers/at32/serial_uart_at32f43x.c

@@ -315,7 +315,7 @@ uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode,
         if ((mode & MODE_TX) && txIO) {
             IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
 
-            if ((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) {
+            if (((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) && !(options & SERIAL_BIDIR_PP_PD)) {
                 uartdev->txPinState = TX_PIN_ACTIVE;
                 // Switch TX to an input with pullup so it's state can be monitored
                 uartTxMonitor(s);

src/main/drivers/stm32/serial_uart_hal.c

@@ -264,9 +264,10 @@ bool checkUsartTxOutput(uartPort_t *s)
 void uartTxMonitor(uartPort_t *s)
 {
     uartDevice_t *uart = container_of(s, uartDevice_t, port);
-    IO_t txIO = IOGetByTag(uart->tx.pin);
 
     if (uart->txPinState == TX_PIN_ACTIVE) {
+        IO_t txIO = IOGetByTag(uart->tx.pin);
+
         // Switch TX to an input with pullup so it's state can be monitored
         uart->txPinState = TX_PIN_MONITOR;
         IOConfigGPIO(txIO, IOCFG_IPU);

src/main/drivers/stm32/serial_uart_stm32f4xx.c

@@ -245,9 +245,10 @@ bool checkUsartTxOutput(uartPort_t *s)
 void uartTxMonitor(uartPort_t *s)
 {
     uartDevice_t *uart = container_of(s, uartDevice_t, port);
-    IO_t txIO = IOGetByTag(uart->tx.pin);
 
     if (uart->txPinState == TX_PIN_ACTIVE) {
+        IO_t txIO = IOGetByTag(uart->tx.pin);
+
         // Switch TX to an input with pullup so it's state can be monitored
         uart->txPinState = TX_PIN_MONITOR;
         IOConfigGPIO(txIO, IOCFG_IPU);
@@ -334,7 +335,7 @@ uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode,
         if ((mode & MODE_TX) && txIO) {
             IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
 
-            if ((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) {
+            if (((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) && !(options & SERIAL_BIDIR_PP_PD)) {
                 uart->txPinState = TX_PIN_ACTIVE;
                 // Switch TX to an input with pullup so it's state can be monitored
                 uartTxMonitor(s);

src/main/drivers/stm32/serial_uart_stm32f7xx.c

@@ -376,7 +376,7 @@ uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode,
         if ((mode & MODE_TX) && txIO) {
             IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
 
-            if ((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) {
+            if (((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) && !(options & SERIAL_BIDIR_PP_PD)) {
                 uartdev->txPinState = TX_PIN_ACTIVE;
                 // Switch TX to an input with pullup so it's state can be monitored
                 uartTxMonitor(s);

src/main/drivers/stm32/serial_uart_stm32g4xx.c

@@ -309,7 +309,7 @@ uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode,
         if ((mode & MODE_TX) && txIO) {
             IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
 
-            if ((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) {
+            if (((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) && !(options & SERIAL_BIDIR_PP_PD)) {
                 uartdev->txPinState = TX_PIN_ACTIVE;
                 // Switch TX to an input with pullup so it's state can be monitored
                 uartTxMonitor(s);

src/main/drivers/stm32/serial_uart_stm32h7xx.c

@@ -486,7 +486,7 @@ uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode,
         if ((mode & MODE_TX) && txIO) {
             IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
 
-            if ((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) {
+            if (((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) && !(options & SERIAL_BIDIR_PP_PD)) {
                 uartdev->txPinState = TX_PIN_ACTIVE;
                 // Switch TX to an input with pullup so it's state can be monitored
                 uartTxMonitor(s);

src/main/io/vtx_smartaudio.c

@@ -707,12 +707,7 @@ bool vtxSmartAudioInit(void)
     // the SA protocol instead requires pulldowns, and therefore uses SERIAL_BIDIR_PP_PD instead of SERIAL_BIDIR_PP
     const serialPortConfig_t *portConfig = findSerialPortConfig(FUNCTION_VTX_SMARTAUDIO);
     if (portConfig) {
-        portOptions_e portOptions = SERIAL_STOPBITS_2 | SERIAL_BIDIR_NOPULL;
+        portOptions_e portOptions = SERIAL_STOPBITS_2 | SERIAL_BIDIR | SERIAL_BIDIR_PP_PD;
-#if defined(USE_VTX_COMMON)
-        portOptions = portOptions | (vtxConfig()->halfDuplex ? SERIAL_BIDIR | SERIAL_BIDIR_PP_PD : SERIAL_UNIDIR);
-#else
-        portOptions = SERIAL_BIDIR;
-#endif
 
         smartAudioSerialPort = openSerialPort(portConfig->identifier, FUNCTION_VTX_SMARTAUDIO, NULL, NULL, 4800, MODE_RXTX, portOptions);
     }