tests: uart: add support for xg29_rb4412a board with elementary test

Added overlay for the silabs xg29_rb4412a board regarding uart_elementary.

Signed-off-by: Martin Hoff <[email protected]>

Author: Martinhoff-maker

tests/drivers/uart/uart_elementary/boards/xg29_rb4412a.overlay

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2025, Silicon Laboratories Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * Connect EXP4 (PC0) and EXP6 (PC1) of the Expansion Pin header
+ */
+/ {
+	chosen {
+		zephyr,console = &eusart0;
+		zephyr,shell-uart = &eusart0;
+		zephyr,uart-pipe = &eusart0;
+	};
+};
+
+&pinctrl{
+	usart0_default: usart0_default {
+		group0 {
+			pins = <USART0_TX_PC0>; /* WPK EXP4 (PC0) */
+			drive-push-pull;
+			output-high;
+		};
+		group1 {
+			pins = <USART0_RX_PC1>; /* WPK EXP6 (PC1) */
+			input-enable;
+			silabs,input-filter;
+		};
+	};
+	eusart0_default: eusart0_default {
+		group0 {
+			pins = <EUSART0_TX_PA5>;
+			drive-push-pull;
+			output-high;
+		};
+		group1 {
+			pins = <EUSART0_RX_PA6>;
+			input-enable;
+			silabs,input-filter;
+		};
+	};
+};
+
+dut: &usart0 {
+	pinctrl-0 = <&usart0_default>;
+	pinctrl-names = "default";
+	current-speed = <115200>;
+	status = "okay";
+};
+
+&eusart0 {
+	compatible = "silabs,eusart-uart";
+	current-speed = <115200>;
+	pinctrl-0 = <&eusart0_default>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
+&eusart1 {
+	status = "disabled";
+};
+
+&usart1 {
+	status = "disabled";
+};

tests/drivers/uart/uart_elementary/testcase.yaml

@@ -27,6 +27,7 @@ tests:
       - esp32s3_devkitm/esp32s3/procpu
       - xg24_rb4187c
       - bg29_rb4420a
+      - xg29_rb4412a
     integration_platforms:
       - nrf54h20dk/nrf54h20/cpuapp
   drivers.uart.uart_elementary_dual_nrf54h: