feat(uart): Refactor UART signal inversion handling

Refactor UART inversion functions to use a helper for signal inversion. Update UART bus array structure to include inversion mask.

Author: SuGlider

cores/esp32/esp32-hal-uart.c

@@ -59,6 +59,7 @@ struct uart_struct_t {
   bool _inverted;                             // UART inverted signal
   uint8_t _rxfifo_full_thrhd;                 // UART RX FIFO full threshold
   int8_t _uart_clock_source;                  // UART Clock Source used when it is started using uartBegin()
+  uint32_t inv_mask;                          // UART inverse mask used to maintain related pin state
 };
 
 #if CONFIG_DISABLE_HAL_LOCKS
@@ -67,21 +68,21 @@ struct uart_struct_t {
 #define UART_MUTEX_UNLOCK()
 
 static uart_t _uart_bus_array[] = {
-  {0, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {0, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #if SOC_UART_NUM > 1
-  {1, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {1, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #endif
 #if SOC_UART_NUM > 2
-  {2, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {2, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #endif
 #if SOC_UART_NUM > 3
-  {3, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {3, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #endif
 #if SOC_UART_NUM > 4
-  {4, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {4, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #endif
 #if SOC_UART_NUM > 5
-  {5, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {5, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #endif
 };
 
@@ -96,21 +97,21 @@ static uart_t _uart_bus_array[] = {
   xSemaphoreGive(uart->lock)
 
 static uart_t _uart_bus_array[] = {
-  {NULL, 0, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {NULL, 0, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #if SOC_UART_NUM > 1
-  {NULL, 1, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {NULL, 1, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #endif
 #if SOC_UART_NUM > 2
-  {NULL, 2, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {NULL, 2, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #endif
 #if SOC_UART_NUM > 3
-  {NULL, 3, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {NULL, 3, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #endif
 #if SOC_UART_NUM > 4
-  {NULL, 4, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {NULL, 4, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #endif
 #if SOC_UART_NUM > 5
-  {NULL, 5, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1},
+  {NULL, 5, false, 0, NULL, -1, -1, -1, -1, 0, 0, 0, 0, false, 0, -1, 0},
 #endif
 };
 
@@ -712,9 +713,15 @@ uart_t *uartBegin(
     if (inverted) {
       // invert signal for both Rx and Tx
       retCode &= ESP_OK == uart_set_line_inverse(uart_nr, UART_SIGNAL_TXD_INV | UART_SIGNAL_RXD_INV);
+      if (retCode) {
+        inv_mask |= UART_SIGNAL_TXD_INV | UART_SIGNAL_RXD_INV;
+      }
     } else {
       // disable invert signal for both Rx and Tx
       retCode &= ESP_OK == uart_set_line_inverse(uart_nr, UART_SIGNAL_INV_DISABLE);
+      if (retCode) {
+        inv_mask &= ~(UART_SIGNAL_TXD_INV | UART_SIGNAL_RXD_INV);
+      }
     }
   }
   // if all fine, set internal parameters
@@ -823,62 +830,49 @@ void uartEnd(uint8_t uart_num) {
   UART_MUTEX_UNLOCK();
 }
 
-void uartSetRxInvert(uart_t *uart, bool invert) {
+// Helper generic function that takes a uart_sigenl_inv_t mask to be properly applied to the designated uart pin
+// invMask can be UART_SIGNAL_RXD_INV, UART_SIGNAL_TXD_INV, UART_SIGNAL_RTS_INV, UART_SIGNAL_CTS_INV
+// returns the operation success status
+bool _uartPinSignalInversion(uart_t *uart, uint32_t invMask, bool inverted) {
   if (uart == NULL) {
     return;
   }
-  // POTENTIAL ISSUE :: original code only set/reset rxd_inv bit
-  // IDF or LL set/reset the whole inv_mask!
-  // if (invert)
-  //     ESP_ERROR_CHECK(uart_set_line_inverse(uart->num, UART_SIGNAL_RXD_INV));
-  // else
-  //     ESP_ERROR_CHECK(uart_set_line_inverse(uart->num, UART_SIGNAL_INV_DISABLE));
-  // this implementation is better over IDF API because it only affects RXD
-  uart_dev_t *hw = UART_LL_GET_HW(uart->num);
-
-#if CONFIG_IDF_TARGET_ESP32C6 || CONFIG_IDF_TARGET_ESP32H2 || CONFIG_IDF_TARGET_ESP32P4
-  if (invert) {
-    hw->conf0_sync.rxd_inv = 1;
-  } else {
-    hw->conf0_sync.rxd_inv = 0;
-  }
-#else
-  // this is supported in ESP32, ESP32-S2 and ESP32-C3
-  if (invert) {
-    hw->conf0.rxd_inv = 1;
+  bool retCode = true;
+  uint32_t _inv_mask = inv_mask;
+  if (inverted) {
+    _inv_mask |= invMask;    
+    retCode = ESP_OK == uart_set_line_inverse(uart->num, _inv_mask);
+    if (retCode) {
+      inv_mask = _inv_mask;
+    } else {
+      retCode = false;
+    }
   } else {
-    hw->conf0.rxd_inv = 0;
+    _inv_mask &= ~invMask;    
+    retCode = ESP_OK == uart_set_line_inverse(uart->num, _inv_mask);
+    if (retCode) {
+      inv_mask = _inv_mask;
+    } else {
+      retCode = false;
+    }
   }
-#endif
+  return retCode;
 }
 
-void uartSetTxInvert(uart_t *uart, bool invert) {
-  if (uart == NULL) {
-    return;
-  }
-  // POTENTIAL ISSUE :: original code only set/reset txd_inv bit
-  // IDF or LL set/reset the whole inv_mask!
-  // if (invert)
-  //     ESP_ERROR_CHECK(uart_set_line_inverse(uart->num, UART_SIGNAL_TXD_INV));
-  // else
-  //     ESP_ERROR_CHECK(uart_set_line_inverse(uart->num, UART_SIGNAL_INV_DISABLE));
-  // this implementation is better over IDF API because it only affects TXD
-  uart_dev_t *hw = UART_LL_GET_HW(uart->num);
+bool uartSetRxInvert(uart_t *uart, bool invert) {
+  return _uartPinSignalInversion(uart, UART_SIGNAL_RXD_INV, invert);
+}
 
-#if CONFIG_IDF_TARGET_ESP32C6 || CONFIG_IDF_TARGET_ESP32H2 || CONFIG_IDF_TARGET_ESP32P4
-  if (invert) {
-    hw->conf0_sync.txd_inv = 1;
-  } else {
-    hw->conf0_sync.txd_inv = 0;
-  }
-#else
-  // this is supported in ESP32, ESP32-S2 and ESP32-C3
-  if (invert) {
-    hw->conf0.txd_inv = 1;
-  } else {
-    hw->conf0.txd_inv = 0;
-  }
-#endif
+bool uartSetTxInvert(uart_t *uart, bool invert) {
+  return _uartPinSignalInversion(uart, UART_SIGNAL_RXD_INV, invert);
+}
+
+bool uartSetCtsInvert(uart_t *uart, bool invert) {
+  return _uartPinSignalInversion(uart, UART_SIGNAL_CTS_INV, invert);
+}
+
+bool uartSetRtsInvert(uart_t *uart, bool invert) {
+  return _uartPinSignalInversion(uart, UART_SIGNAL_RTS_INV, invert);
 }
 
 uint32_t uartAvailable(uart_t *uart) {