imx8mn_var_som: Add support for Variscite VAR-SOM-MX8M-NANO board

Add support for iMX8MN VAR-SOM-MX8M-NANO board. Enables support for:

- 1GiB DDR4 RAM
- 16 GiB eMMC
- SD card
- Gigabit ethernet
- USBOTG1 peripheral - fastboot

Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@collabora.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/arch/arm/dts/imx8mn-var-som-symphony-u-boot.dtsi b/arch/arm/dts/imx8mn-var-som-symphony-u-boot.dtsi
new file mode 100644
index 0000000..ce47588
--- /dev/null
+++ b/arch/arm/dts/imx8mn-var-som-symphony-u-boot.dtsi
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2021 Collabora Ltd.
+ */
+
+/ {
+	binman: binman {
+		multiple-images;
+	};
+
+	wdt-reboot {
+		compatible = "wdt-reboot";
+		wdt = <&wdog1>;
+		u-boot,dm-spl;
+	};
+};
+
+&{/soc@0} {
+	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
+};
+
+&{/soc@0/bus@30800000/i2c@30a20000/pmic@4b} {
+	u-boot,dm-spl;
+};
+
+&{/soc@0/bus@30800000/i2c@30a20000/pmic@4b/regulators} {
+	u-boot,dm-spl;
+};
+
+&aips1 {
+	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
+};
+
+&aips3 {
+	u-boot,dm-spl;
+};
+
+&aips4 {
+	u-boot,dm-spl;
+};
+
+&clk {
+	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
+	/delete-property/ assigned-clocks;
+	/delete-property/ assigned-clock-parents;
+	/delete-property/ assigned-clock-rates;
+};
+
+&gpio1 {
+	u-boot,dm-spl;
+};
+
+&gpio2 {
+	u-boot,dm-spl;
+};
+
+&gpio4 {
+	u-boot,dm-spl;
+};
+
+&i2c1 {
+	u-boot,dm-spl;
+};
+
+&iomuxc {
+	u-boot,dm-spl;
+};
+
+&osc_24m {
+	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
+};
+
+&pinctrl_i2c1 {
+	u-boot,dm-spl;
+};
+
+&pinctrl_pmic {
+	u-boot,dm-spl;
+};
+
+&pinctrl_reg_usdhc2_vmmc {
+	u-boot,dm-spl;
+};
+
+&pinctrl_uart4 {
+	u-boot,dm-spl;
+};
+
+&pinctrl_usdhc2 {
+	u-boot,dm-spl;
+};
+
+&pinctrl_usdhc3 {
+	u-boot,dm-spl;
+};
+
+&pinctrl_wdog {
+	u-boot,dm-spl;
+};
+
+&uart4 {
+	u-boot,dm-spl;
+};
+
+&usdhc2 {
+	u-boot,dm-spl;
+};
+
+&usdhc3 {
+	u-boot,dm-spl;
+};
+
+&wdog1 {
+	u-boot,dm-spl;
+};
+
+&binman {
+	u-boot-spl-ddr {
+		align = <4>;
+		align-size = <4>;
+		filename = "u-boot-spl-ddr.bin";
+		pad-byte = <0xff>;
+
+		u-boot-spl {
+			align-end = <4>;
+			filename = "u-boot-spl.bin";
+		};
+
+		1d-imem {
+			filename = "ddr4_imem_1d.bin";
+			size = <0x8000>;
+			type = "blob-ext";
+		};
+
+		1d_dmem {
+			filename = "ddr4_dmem_1d.bin";
+			size = <0x4000>;
+			type = "blob-ext";
+		};
+
+		2d_imem {
+			filename = "ddr4_imem_2d.bin";
+			size = <0x8000>;
+			type = "blob-ext";
+		};
+
+		2d_dmem {
+			filename = "ddr4_dmem_2d.bin";
+			size = <0x4000>;
+			type = "blob-ext";
+		};
+	};
+
+	spl {
+		filename = "spl.bin";
+
+		mkimage {
+			args = "-n spl/u-boot-spl.cfgout -T imx8mimage -e 0x912000";
+
+			blob {
+				filename = "u-boot-spl-ddr.bin";
+			};
+		};
+	};
+
+	itb {
+		filename = "u-boot.itb";
+
+		fit {
+			description = "Configuration to load ATF before U-Boot";
+			fit,external-offset = <CONFIG_FIT_EXTERNAL_OFFSET>;
+			fit,fdt-list = "of-list";
+			#address-cells = <1>;
+
+			images {
+				uboot {
+					arch = "arm64";
+					compression = "none";
+					description = "U-Boot (64-bit)";
+					load = <CONFIG_SYS_TEXT_BASE>;
+					type = "standalone";
+
+					uboot_blob {
+						filename = "u-boot-nodtb.bin";
+						type = "blob-ext";
+					};
+				};
+
+				atf {
+					arch = "arm64";
+					compression = "none";
+					description = "ARM Trusted Firmware";
+					entry = <0x960000>;
+					load = <0x960000>;
+					type = "firmware";
+
+					atf_blob {
+						filename = "bl31.bin";
+						type = "blob-ext";
+					};
+				};
+
+				binman_fip: fip {
+					arch = "arm64";
+					compression = "none";
+					description = "Trusted Firmware FIP";
+					load = <0x40310000>;
+					type = "firmware";
+				};
+
+				@fdt-SEQ {
+					compression = "none";
+					description = "NAME";
+					type = "flat_dt";
+
+					uboot_fdt_blob {
+						filename = "u-boot.dtb";
+						type = "blob-ext";
+					};
+				};
+			};
+
+			configurations {
+				default = "@config-DEFAULT-SEQ";
+
+				binman_configuration: @config-SEQ {
+					description = "NAME";
+					fdt = "fdt-SEQ";
+					firmware = "uboot";
+					loadables = "atf";
+				};
+			};
+		};
+	};
+
+	imx-boot {
+		filename = "flash.bin";
+		pad-byte = <0x00>;
+
+		spl {
+			filename = "spl.bin";
+			offset = <0x0>;
+			type = "blob-ext";
+		};
+
+		binman_uboot: uboot {
+			filename = "u-boot.itb";
+			offset = <0x58000>;
+			type = "blob-ext";
+		};
+	};
+};