openthread: add a configuration for selecting RCP UART TX_RX

examples/openthread/ot_rcp/main/Kconfig.projbuild

@@ -0,0 +1,21 @@
+menu "OpenThread RCP Example"
+
+    config OPENTHREAD_UART_PIN_MANUAL
+        bool "Configure RCP UART pin manually"
+        default n
+        help
+            Select this to choose UART pin manually
+
+    config OPENTHREAD_UART_RX_PIN
+        int "The number of RX pin"
+        depends on OPENTHREAD_UART_PIN_MANUAL
+        default 4
+        range 0 25
+
+    config OPENTHREAD_UART_TX_PIN
+        int "The number of TX pin"
+        depends on OPENTHREAD_UART_PIN_MANUAL
+        default 5
+        range 0 25
+
+endmenu

examples/openthread/ot_rcp/main/esp_ot_config.h

@@ -20,6 +20,14 @@
         .radio_mode = RADIO_MODE_NATIVE,                        \
     }
 
+#if CONFIG_OPENTHREAD_UART_PIN_MANUAL
+#define OPENTHREAD_RCP_UART_RX_PIN CONFIG_OPENTHREAD_UART_RX_PIN
+#define OPENTHREAD_RCP_UART_TX_PIN CONFIG_OPENTHREAD_UART_TX_PIN
+#else
+#define OPENTHREAD_RCP_UART_RX_PIN UART_PIN_NO_CHANGE
+#define OPENTHREAD_RCP_UART_TX_PIN UART_PIN_NO_CHANGE
+#endif
+
 #define ESP_OPENTHREAD_DEFAULT_HOST_CONFIG()                    \
     {                                                           \
         .host_connection_mode = HOST_CONNECTION_MODE_RCP_UART,  \
@@ -35,8 +43,8 @@
                     .rx_flow_ctrl_thresh = 0,                   \
                     .source_clk = UART_SCLK_DEFAULT,            \
                 },                                              \
-            .rx_pin = UART_PIN_NO_CHANGE,                       \
-            .tx_pin = UART_PIN_NO_CHANGE,                       \
+            .rx_pin = OPENTHREAD_RCP_UART_RX_PIN,               \
+            .tx_pin = OPENTHREAD_RCP_UART_TX_PIN,               \
         },                                                      \
     }