boards: imx8mn_evk_a53: add i2c gpio expander support

Added gpio expander pca6416 support on the board, it use i2c bus to
expand IO ports.

Added GPIO test case overlay for the board.

Signed-off-by: Jiafei Pan <[email protected]>

Author: JiafeiPan

boards/nxp/imx8mn_evk/imx8mn_evk-pinctrl.dtsi

@@ -63,4 +63,16 @@
 			drive-strength = "x6";
 		};
 	};
+
+	pinmux_i2c3: pinmux_i2c3 {
+		group0 {
+			pinmux = <&iomuxc_i2c3_scl_i2c_scl_i2c3_scl>,
+				<&iomuxc_i2c3_sda_i2c_sda_i2c3_sda>;
+			bias-pull-up;
+			input-schmitt-enable;
+			slew-rate = "slow";
+			drive-strength = "x4";
+			input-enable;
+		};
+	};
 };

boards/nxp/imx8mn_evk/imx8mn_evk_mimx8mn6_a53.dts

@@ -6,6 +6,8 @@
 
 /dts-v1/;
 
+#include <zephyr/dt-bindings/gpio/gpio.h>
+#include <zephyr/dt-bindings/i2c/i2c.h>
 #include <nxp/nxp_mimx8mn_a53.dtsi>
 #include "imx8mn_evk-pinctrl.dtsi"
 
@@ -67,3 +69,23 @@
 	pinctrl-names = "default";
 	status = "okay";
 };
+
+&gpio1 {
+	status = "okay";
+};
+
+&i2c3 {
+	status = "okay";
+	pinctrl-0 = <&pinmux_i2c3>;
+	pinctrl-names = "default";
+	clock-frequency = <I2C_BITRATE_STANDARD>;
+
+	gpio_exp1: pca6416@20 {
+		compatible = "nxp,pca6416";
+		reg = <0x20>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		interrupt-gpios = <&gpio1 12 (GPIO_ACTIVE_LOW|GPIO_PULL_UP)>;
+		status = "okay";
+	};
+};

tests/drivers/gpio/gpio_basic_api/boards/imx8mn_evk_mimx8mn6_a53.overlay

@@ -0,0 +1,18 @@
+/*
+ * Copyright 2024 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/{
+	resources {
+		compatible = "test-gpio-basic-api";
+		/*
+		 * Use connector J1003 Pin-12 GPIO.1 which connect to pca6416 P1_2 as input
+		 * GPIO, and connector J1003 Pin-16 GPIO.4 which connect to pca6416 P1_5 as
+		 * output GPIO, connect these two pins with a Dupont Line.
+		 */
+		out-gpios = <&gpio_exp1 10 0>;
+		in-gpios = <&gpio_exp1 13 0>;
+	};
+};