board: phytec: phycore-imx93: Add phyBOARD-Segin-i.MX93 support

Add initial support for the PHYTEC phyBOARD-Segin-i.MX93 board based on
the PHYTEC phyCORE-i.MX93 SoM.

Supported features:
- 1GB LPDDR4 RAM
- eMMC
- external SD
- FEC Ethernet
- debug UART
- watchdog

Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
Tested-by: Primoz Fiser <primoz.fiser@norik.com>
Reviewed-by: Yannic Moog <y.moog@phytec.de>
diff --git a/arch/arm/dts/imx93-phyboard-segin.dts b/arch/arm/dts/imx93-phyboard-segin.dts
new file mode 100644
index 0000000..85fb188
--- /dev/null
+++ b/arch/arm/dts/imx93-phyboard-segin.dts
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (C) 2023 PHYTEC Messtechnik GmbH
+ * Author: Wadim Egorov <w.egorov@phytec.de>, Christoph Stoidner <c.stoidner@phytec.de>
+ * Copyright (C) 2024 Mathieu Othacehe <m.othacehe@gmail.com>
+ *
+ * Product homepage:
+ * phyBOARD-Segin carrier board is reused for the i.MX93 design.
+ * https://www.phytec.eu/en/produkte/single-board-computer/phyboard-segin-imx6ul/
+ */
+/dts-v1/;
+
+#include "imx93-phycore-som.dtsi"
+
+/{
+	model = "PHYTEC phyBOARD-Segin-i.MX93";
+	compatible = "phytec,imx93-phyboard-segin", "phytec,imx93-phycore-som",
+		     "fsl,imx93";
+
+	chosen {
+		stdout-path = &lpuart1;
+	};
+
+	reg_usdhc2_vmmc: regulator-usdhc2 {
+		compatible = "regulator-fixed";
+		enable-active-high;
+		gpio = <&gpio3 7 GPIO_ACTIVE_HIGH>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_reg_usdhc2_vmmc>;
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-name = "VCC_SD";
+	};
+};
+
+/* Console */
+&lpuart1 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_uart1>;
+	status = "okay";
+};
+
+/* eMMC */
+&usdhc1 {
+	no-1-8-v;
+};
+
+/* SD-Card */
+&usdhc2 {
+	pinctrl-names = "default", "state_100mhz", "state_200mhz";
+	pinctrl-0 = <&pinctrl_usdhc2_default>, <&pinctrl_usdhc2_cd>;
+	pinctrl-1 = <&pinctrl_usdhc2_100mhz>, <&pinctrl_usdhc2_cd>;
+	pinctrl-2 = <&pinctrl_usdhc2_200mhz>, <&pinctrl_usdhc2_cd>;
+	bus-width = <4>;
+	cd-gpios = <&gpio3 0 GPIO_ACTIVE_LOW>;
+	no-mmc;
+	no-sdio;
+	vmmc-supply = <&reg_usdhc2_vmmc>;
+	status = "okay";
+};
+
+&iomuxc {
+	pinctrl_uart1: uart1grp {
+		fsl,pins = <
+			MX93_PAD_UART1_RXD__LPUART1_RX		0x31e
+			MX93_PAD_UART1_TXD__LPUART1_TX		0x30e
+		>;
+	};
+
+	pinctrl_reg_usdhc2_vmmc: regusdhc2vmmcgrp {
+		fsl,pins = <
+			MX93_PAD_SD2_RESET_B__GPIO3_IO07	0x31e
+		>;
+	};
+
+	pinctrl_usdhc2_cd: usdhc2cdgrp {
+		fsl,pins = <
+			MX93_PAD_SD2_CD_B__GPIO3_IO00		0x31e
+		>;
+	};
+
+	pinctrl_usdhc2_default: usdhc2grp {
+		fsl,pins = <
+			MX93_PAD_SD2_CLK__USDHC2_CLK		0x179e
+			MX93_PAD_SD2_CMD__USDHC2_CMD		0x139e
+			MX93_PAD_SD2_DATA0__USDHC2_DATA0	0x138e
+			MX93_PAD_SD2_DATA1__USDHC2_DATA1	0x138e
+			MX93_PAD_SD2_DATA2__USDHC2_DATA2	0x138e
+			MX93_PAD_SD2_DATA3__USDHC2_DATA3	0x139e
+			MX93_PAD_SD2_VSELECT__USDHC2_VSELECT	0x51e
+		>;
+	};
+
+	pinctrl_usdhc2_100mhz: usdhc2grp {
+		fsl,pins = <
+			MX93_PAD_SD2_CLK__USDHC2_CLK            0x179e
+			MX93_PAD_SD2_CMD__USDHC2_CMD            0x139e
+			MX93_PAD_SD2_DATA0__USDHC2_DATA0        0x138e
+			MX93_PAD_SD2_DATA1__USDHC2_DATA1        0x138e
+			MX93_PAD_SD2_DATA2__USDHC2_DATA2        0x139e
+			MX93_PAD_SD2_DATA3__USDHC2_DATA3        0x139e
+			MX93_PAD_SD2_VSELECT__USDHC2_VSELECT    0x51e
+		>;
+	};
+
+	pinctrl_usdhc2_200mhz: usdhc2grp {
+		fsl,pins = <
+			MX93_PAD_SD2_CLK__USDHC2_CLK            0x178e
+			MX93_PAD_SD2_CMD__USDHC2_CMD            0x139e
+			MX93_PAD_SD2_DATA0__USDHC2_DATA0        0x139e
+			MX93_PAD_SD2_DATA1__USDHC2_DATA1        0x139e
+			MX93_PAD_SD2_DATA2__USDHC2_DATA2        0x139e
+			MX93_PAD_SD2_DATA3__USDHC2_DATA3        0x139e
+			MX93_PAD_SD2_VSELECT__USDHC2_VSELECT    0x51e
+		>;
+	};
+};