UART - Add generic pin/swap functionality.

If RX pin resource is assigned to a TX hardware pin, or vice versa, then pin-swap is enabled.
betaflight · Sep 6, 2021 · b5a61f6 · b5a61f6
1 parent 8ca4fdc
commit b5a61f6
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Showing 3 changed files with 51 additions and 2 deletions.
diff --git a/src/main/drivers/serial_uart_hal.c b/src/main/drivers/serial_uart_hal.c
@@ -64,6 +64,34 @@ static void usartConfigurePinInversion(uartPort_t *uartPort) {
     }
 }
 
+static uartDevice_t *uartFindDevice(uartPort_t *uartPort)
+{
+    for (uint32_t i = 0; i < UARTDEV_COUNT_MAX; i++) {
+        uartDevice_t *candidate = uartDevmap[i];
+
+        if (&candidate->port == uartPort) {
+            return candidate;
+        }
+    }
+    return NULL;
+}
+
+static void uartConfigurePinSwap(uartPort_t *uartPort)
+{
+#if (defined(STM32F1) || defined(STM32F4))
+    // Older CPUs don't support pin swap.
+    UNUSED(uartPart);
+#else
+    uartDevice_t *uartDevice = uartFindDevice(uartPort);
+    if (!uartDevice) return NULL;
+
+    if (uartDevice->pinSwap) {
+        uartDevice->port.Handle.AdvancedInit.AdvFeatureInit |= UART_ADVFEATURE_SWAP_INIT;
+        uartDevice->port.Handle.AdvancedInit.Swap = UART_ADVFEATURE_SWAP_ENABLE;
+    }
+#endif
+}
+
 // XXX uartReconfigure does not handle resource management properly.
 
 void uartReconfigure(uartPort_t *uartPort)
@@ -91,6 +119,7 @@ void uartReconfigure(uartPort_t *uartPort)
 
 
     usartConfigurePinInversion(uartPort);
+    uartConfigurePinSwap(uartPort);
 
 #ifdef TARGET_USART_CONFIG
     void usartTargetConfigure(uartPort_t *);

diff --git a/src/main/drivers/serial_uart_impl.h b/src/main/drivers/serial_uart_impl.h
@@ -222,6 +222,9 @@ typedef struct uartDevice_s {
     uartPinDef_t tx;
     volatile uint8_t *rxBuffer;
     volatile uint8_t *txBuffer;
+#if !(defined(STM32F1) || defined(STM32F4)) // Older CPUs don't support pin swap.
+    bool pinSwap;
+#endif
 } uartDevice_t;
 
 extern uartDevice_t *uartDevmap[];

diff --git a/src/main/drivers/serial_uart_pinconfig.c b/src/main/drivers/serial_uart_pinconfig.c
@@ -53,14 +53,31 @@ void uartPinConfigure(const serialPinConfig_t *pSerialPinConfig)
         const uartHardware_t *hardware = &uartHardware[hindex];
         const UARTDevice_e device = hardware->device;
 
+#if !(defined(STM32F1) || defined(STM32F4)) // Older CPUs don't support pin swap.
+        uartdev->pinSwap = false;
+#endif
         for (int pindex = 0 ; pindex < UARTHARDWARE_MAX_PINS ; pindex++) {
-            if (hardware->rxPins[pindex].pin == pSerialPinConfig->ioTagRx[device]) {
+            if (pSerialPinConfig->ioTagRx[device] == hardware->rxPins[pindex].pin) {
                 uartdev->rx = hardware->rxPins[pindex];
             }
 
-            if (hardware->txPins[pindex].pin == pSerialPinConfig->ioTagTx[device]) {
+            if (pSerialPinConfig->ioTagTx[device] == hardware->txPins[pindex].pin) {
                 uartdev->tx = hardware->txPins[pindex];
             }
+
+
+#if !(defined(STM32F1) || defined(STM32F4))
+            // Check for swapped pins
+            if (pSerialPinConfig->ioTagTx[device] == hardware->rxPins[pindex].pin) {
+                uartdev->tx = hardware->rxPins[pindex];
+                uartdev->pinSwap = true;
+            }
+
+            if (pSerialPinConfig->ioTagRx[device] == hardware->txPins[pindex].pin) {
+                uartdev->rx = hardware->txPins[pindex];
+                uartdev->pinSwap = true;
+            }
+#endif
         }
 
         if (uartdev->rx.pin || uartdev->tx.pin) {