fix(uart): uses IDF 5.x API to set loopback

cores/esp32/HardwareSerial.cpp

@@ -341,13 +341,62 @@ void HardwareSerial::begin(unsigned long baud, uint32_t config, int8_t rxPin, in
       case UART_NUM_2:
         if (rxPin < 0 && txPin < 0) {
           // do not change RX2/TX2 if it has already been set before
+#ifdef RX2
           rxPin = _rxPin < 0 ? (int8_t)RX2 : _rxPin;
+#else
+          rxPin = _rxPin;
+#endif
+#ifdef TX2
           txPin = _txPin < 0 ? (int8_t)TX2 : _txPin;
+#else
+          txPin = _txPin;
+#endif
+        }
+        break;
+#endif
+#if SOC_UART_HP_NUM > 3  // may save some flash bytes...
+      case UART_NUM_3:
+        if (rxPin < 0 && txPin < 0) {
+          // do not change RX2/TX2 if it has already been set before
+#ifdef RX3
+          rxPin = _rxPin < 0 ? (int8_t)RX3 : _rxPin;
+#else
+          rxPin = _rxPin;
+#endif
+#ifdef TX3
+          txPin = _txPin < 0 ? (int8_t)TX3 : _txPin;
+#else
+          txPin = _txPin;
+#endif
+        }
+        break;
+#endif
+#if SOC_UART_HP_NUM > 4  // may save some flash bytes...
+      case UART_NUM_4:
+        if (rxPin < 0 && txPin < 0) {
+          // do not change RX2/TX2 if it has already been set before
+#ifdef RX4
+          rxPin = _rxPin < 0 ? (int8_t)RX4 : _rxPin;
+#else
+          rxPin = _rxPin;
+#endif
+#ifdef TX4
+          txPin = _txPin < 0 ? (int8_t)TX4 : _txPin;
+#else
+          txPin = _txPin;
+#endif
         }
         break;
 #endif
     }
   }
+
+  // if no RX/TX pins are defined, it will not start the UART driver
+  if (rxPin < 0 && txPin < 0) {
+    log_e("No RX/TX pins defined. Please set RX/TX pins.");
+    HSERIAL_MUTEX_UNLOCK();
+    return;
+  }
 
   // IDF UART driver keeps Pin setting on restarting. Negative Pin number will keep it unmodified.
   // it will detach previous UART attached pins

cores/esp32/HardwareSerial.h

@@ -200,8 +200,6 @@ typedef enum {
 #define RX2 (gpio_num_t)4
 #elif CONFIG_IDF_TARGET_ESP32S3
 #define RX2 (gpio_num_t)19
-#elif CONFIG_IDF_TARGET_ESP32P4
-#define RX2 (gpio_num_t)15
 #endif
 #endif
 
@@ -210,8 +208,6 @@ typedef enum {
 #define TX2 (gpio_num_t)25
 #elif CONFIG_IDF_TARGET_ESP32S3
 #define TX2 (gpio_num_t)20
-#elif CONFIG_IDF_TARGET_ESP32P4
-#define TX2 (gpio_num_t)14
 #endif
 #endif
 #endif /* SOC_UART_HP_NUM > 2 */

cores/esp32/esp32-hal-uart.c

@@ -166,13 +166,15 @@ static bool _uartDetachBus_RX(void *busptr) {
   // sanity check - it should never happen
   assert(busptr && "_uartDetachBus_RX bus NULL pointer.");
   uart_t *bus = (uart_t *)busptr;
+  uart_set_loop_back(bus->num, false); // disable loopback
   return _uartDetachPins(bus->num, bus->_rxPin, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
 }
 
 static bool _uartDetachBus_TX(void *busptr) {
   // sanity check - it should never happen
   assert(busptr && "_uartDetachBus_TX bus NULL pointer.");
   uart_t *bus = (uart_t *)busptr;
+  uart_set_loop_back(bus->num, false); // disable loopback
   return _uartDetachPins(bus->num, UART_PIN_NO_CHANGE, bus->_txPin, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
 }
 
@@ -1164,11 +1166,11 @@ unsigned long uartDetectBaudrate(uart_t *uart) {
    This function internally binds defined UARTs TX signal with defined RX pin of any UART (same or different).
    This creates a loop that lets us receive anything we send on the UART without external wires.
 */
-void uart_internal_loopback(uint8_t uartNum, int8_t rxPin) {
-  if (uartNum > SOC_UART_HP_NUM - 1 || !GPIO_IS_VALID_GPIO(rxPin)) {
+void uart_internal_loopback(uint8_t uartNum, bool loop_back_en) {
+  if (uartNum > SOC_UART_HP_NUM - 1) {
     return;
   }
-  esp_rom_gpio_connect_out_signal(rxPin, UART_TX_SIGNAL(uartNum), false, false);
+  uart_set_loop_back(uartNum, loop_back_en);
 }
 
 /*

cores/esp32/esp32-hal-uart.h

@@ -106,7 +106,7 @@ unsigned long uartDetectBaudrate(uart_t *uart);
 
 // Make sure UART's RX signal is connected to TX pin
 // This creates a loop that lets us receive anything we send on the UART
-void uart_internal_loopback(uint8_t uartNum, int8_t rxPin);
+void uart_internal_loopback(uint8_t uartNum, bool loop_back_en);
 
 // Routines that generate BREAK in the UART for testing purpose
 

libraries/ESP32/examples/Serial/OnReceiveError_BREAK_Demo/OnReceiveError_BREAK_Demo.ino

@@ -93,7 +93,7 @@ void setup() {
   // GPIO4 <--> GPIO5 using external wire
   Serial1.begin(BAUD, SERIAL_8N1, RXPIN, TXPIN);  // Rx = 4, Tx = 5 will work for ESP32, S2, S3 and C3
 #if USE_INTERNAL_PIN_LOOPBACK
-  uart_internal_loopback(TEST_UART, RXPIN);
+  uart_internal_loopback(TEST_UART, true);
 #endif
 
   for (uint8_t i = 0; i < sizeof(fifoFullTestCases); i++) {

libraries/ESP32/examples/Serial/OnReceive_Demo/OnReceive_Demo.ino

@@ -75,7 +75,7 @@ void setup() {
   // GPIO4 <--> GPIO5 using external wire
   Serial1.begin(BAUD, SERIAL_8N1, RXPIN, TXPIN);  // Rx = 4, Tx = 5 will work for ESP32, S2, S3 and C3
 #if USE_INTERNAL_PIN_LOOPBACK
-  uart_internal_loopback(TEST_UART, RXPIN);
+  uart_internal_loopback(TEST_UART, true);
 #endif
 
   for (uint8_t i = 0; i < sizeof(fifoFullTestCases); i++) {

libraries/ESP32/examples/Serial/RxFIFOFull_Demo/RxFIFOFull_Demo.ino

@@ -47,7 +47,7 @@ void setup() {
   // GPIO4 <--> GPIO5 using external wire
   Serial1.begin(BAUD, SERIAL_8N1, RXPIN, TXPIN);  // Rx = 4, Tx = 5 will work for ESP32, S2, S3 and C3
 #if USE_INTERNAL_PIN_LOOPBACK
-  uart_internal_loopback(TEST_UART, RXPIN);
+  uart_internal_loopback(TEST_UART, true);
 #endif
 
   for (uint8_t i = 0; i < sizeof(fifoFullTestCases); i++) {

libraries/ESP32/examples/Serial/RxTimeout_Demo/RxTimeout_Demo.ino

@@ -47,7 +47,7 @@ void setup() {
   // GPIO4 <--> GPIO5 using external wire
   Serial1.begin(BAUD, SERIAL_8N1, RXPIN, TXPIN);  // Rx = 4, Tx = 5 will work for ESP32, S2, S3 and C3
 #if USE_INTERNAL_PIN_LOOPBACK
-  uart_internal_loopback(TEST_UART, RXPIN);
+  uart_internal_loopback(TEST_UART, true);
 #endif
 
   for (uint8_t i = 0; i < sizeof(rxTimeoutTestCases); i++) {

libraries/ESP32/examples/Serial/Serial_STD_Func_OnReceive/Serial_STD_Func_OnReceive.ino

@@ -89,7 +89,7 @@ void setup() {
   // creating a loopback that will allow to write to TEST_UART number
   // and send it to RX with no need to physically connect both pins
 #if TEST_UART > 0
-  uart_internal_loopback(TEST_UART, RXPIN);
+  uart_internal_loopback(TEST_UART, true);
 #else
   // when UART0 is used for testing, it is necessary to send data using the Serial Monitor/Terminal
   // Data must be sent by the CP2102, manually using  the Serial Monitor/Terminal

tests/validation/periman/periman.ino

@@ -72,7 +72,7 @@ void setup_test(String test_name, int8_t rx_pin = UART1_RX_DEFAULT, int8_t tx_pi
   pinMode(uart1_rx_pin, INPUT_PULLUP);
   pinMode(uart1_tx_pin, OUTPUT);
   Serial1.setPins(uart1_rx_pin, uart1_tx_pin);
-  uart_internal_loopback(1, uart1_rx_pin);
+  uart_internal_loopback(1, true);
   delay(100);
   log_v("Running %s test", test_name.c_str());
 }
@@ -88,7 +88,7 @@ void teardown_test(void) {
     Serial1.flush();
 
     Serial1.setPins(uart1_rx_pin, uart1_tx_pin);
-    uart_internal_loopback(1, uart1_rx_pin);
+    uart_internal_loopback(1, true);
     delay(100);
   }
 
@@ -280,7 +280,7 @@ void setup() {
     delay(10);
   }
   Serial1.onReceive(onReceive_cb);
-  uart_internal_loopback(1, uart1_rx_pin);
+  uart_internal_loopback(1, true);
 
   gpio_test();
   sigmadelta_test();