board/adi/ev-sc598-som: support SPI NAND

board/adi/ev-sc598-som/nand.cfg

@@ -0,0 +1,40 @@
+# Micron 8Gb (1GB) SPI NAND flash
+# Model: MT29F8G01ADAFD12-AAT:F
+# Datasheet: https://www.micron.com/content/dam/micron/global/secure/products/data-sheet/nand-flash/70-series/m70a-4-8gb-nand-spi-auto.pdf
+# Label: U4
+flash nand-1G {
+	pebsize = 256K
+	numpebs = 4096
+	minimum-io-unit-size = 4096
+	sub-page-size = 4096
+	vid-header-offset = 4096
+}
+
+image nand.img {
+	flash {}
+	flashtype = "nand-1G"
+
+	partition u-boot-spl {
+		image = "u-boot-spl.ldr"
+		size = 256K
+	}
+
+	partition u-boot {
+		image = "u-boot.ldr"
+		size = 768K
+	}
+
+	partition dtb {
+		image = "sc598-som-nand.dtb"
+		size = 256K
+	}
+
+	partition kernel {
+		image = "Image"
+		size = 32M
+	}
+
+	partition rootfs {
+		image = "rootfs.ubi"
+	}
+}

board/adi/ev-sc598-som/patches/linux/dts/adi/sc598-som-nand.dts

@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2026 Analog Devices Incorporated
+ */
+
+/dts-v1/;
+
+#include "sc598-som-revE.dtsi"
+
+/ {
+  model = "ADI SC598-SOM with NAND";
+  compatible = "adi,sc598-som-nand", "adi,sc59x-64";
+};
+
+/*
+ * Clock configuration for faster SPI NAND performance.
+ *
+ * Default SPI clock sources (sclk0_0, oclk_0) are both 62.5 MHz, limiting
+ * SPI speed. Reconfigure oclk_0 to 250 MHz instead of using sclk0_0
+ * because sclk0_0 is shared by UARTs, I2C, timers, watchdog, and Ethernet.
+ *
+ *   CGU0_ODIV: 1000 MHz / 4 = 250 MHz (was / 16 = 62.5 MHz)
+ *   SPI_SEL: Use oclk_0 as SPI parent
+ *   EMMC_SEL: Switch eMMC to dclk_0_half (eMMC defaults to oclk_0, which
+ *             would break it at 250 MHz - "Internal clock never stabilised")
+ *
+ * time nanddump /dev/mtd4 -l 1048576 -f /dev/null
+ *   ~21 MHz (original): 0.24s (~4.4 MB/s)
+ *   62.5 MHz: 0.20s (~5.2 MB/s)
+ *   83.3 MHz: 0.19s (~5.5 MB/s)
+ *   125 MHz: probe failed (ID reads 0xffffffff)
+ */
+&clk {
+	assigned-clocks = <&clk ADSP_SC598_CLK_CGU0_ODIV>, <&clk ADSP_SC598_CLK_SPI_SEL>, <&clk ADSP_SC598_CLK_EMMC_SEL>;
+	assigned-clock-rates = <250000000>, <0>, <0>;
+	assigned-clock-parents = <0>, <&clk ADSP_SC598_CLK_CGU0_OCLK>, <&clk ADSP_SC598_CLK_DCLK0_HALF>;
+};
+
+&mmc0 {
+	status = "disabled";
+};
+
+&spi2 {
+	/delete-node/ is25lp01g@0;
+
+	som_flash: spi-nand@0 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "micron,mt29f1g01abafd", "spi-nand";
+		reg = <0>;
+		spi-max-frequency = <83000000>;
+		spi-rx-bus-width = <4>;
+		spi-tx-bus-width = <4>;
+		nand-ecc-mode = "on-die";
+		nand-ecc-strength = <1>;
+		nand-ecc-step-size = <512>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "u-boot-spl";
+				reg = <0x0 0x40000>;
+			};
+
+			partition@40000 {
+				label = "u-boot";
+				reg = <0x40000 0xC0000>;
+			};
+
+			partition@100000 {
+				label = "dtb";
+				reg = <0x100000 0x40000>;
+			};
+
+			partition@140000 {
+				label = "kernel";
+				reg = <0x140000 0x2000000>;
+			};
+
+			partition@2140000 {
+				label = "rootfs";
+				reg = <0x2140000 0x3DEC0000>;
+			};
+		};
+	};
+};

board/adi/ev-sc598-som/patches/linux/nand.fragment

@@ -0,0 +1,2 @@
+CONFIG_MTD_SPI_NAND=y
+CONFIG_MTD_UBI=y

board/adi/ev-sc598-som/patches/uboot/dts/sc598-som-nand.dts

@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2026 Analog Devices Incorporated
+ */
+
+/dts-v1/;
+
+#include "sc598-som-revE.dtsi"
+
+/ {
+  model = "ADI SC598-SOM with NAND";
+  compatible = "adi,sc598-som-nand", "adi,sc59x-64";
+};
+
+&spi2 {
+	/delete-node/ is25lp01g@1;
+
+	som_flash: spi-nand@1 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "spi-nand";
+		reg = <1>;
+		spi-max-frequency = <25000000>;
+		spi-rx-bus-width = <4>;
+		spi-tx-bus-width = <4>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "u-boot-spl";
+				reg = <0x0 0x40000>;
+			};
+
+			partition@40000 {
+				label = "u-boot";
+				reg = <0x40000 0xC0000>;
+			};
+
+			partition@100000 {
+				label = "dtb";
+				reg = <0x100000 0x40000>;
+			};
+
+			partition@140000 {
+				label = "kernel";
+				reg = <0x140000 0x2000000>;
+			};
+
+			partition@2140000 {
+				label = "rootfs";
+				reg = <0x2140000 0x3DEC0000>;
+			};
+		};
+	};
+};

board/adi/ev-sc598-som/patches/uboot/nand.fragment

@@ -0,0 +1,4 @@
+CONFIG_DEFAULT_DEVICE_TREE="sc598-som-nand"
+CONFIG_DM_MTD=y
+CONFIG_MTD_SPI_NAND=y
+CONFIG_SUPPORT_RAW_INITRD=y

configs/adi_sc598_nand.fragment

@@ -0,0 +1,9 @@
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="adi/sc598-som-nand"
+BR2_LINUX_KERNEL_CUSTOM_DTS_DIR="$(BR2_EXTERNAL)/board/adi/ev-sc598-som/patches/linux/dts/"
+BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="$(BR2_EXTERNAL)/board/adi/ev-sc598-som/patches/linux/nand.fragment"
+BR2_TARGET_UBOOT_CUSTOM_DTS_PATH="$(BR2_EXTERNAL)/board/adi/ev-sc598-som/patches/uboot/dts/sc598-som-nand.dts"
+BR2_TARGET_UBOOT_CONFIG_FRAGMENT_FILES="$(BR2_EXTERNAL)/board/adi/ev-sc598-som/patches/uboot/nand.fragment"
+BR2_ROOTFS_POST_IMAGE_SCRIPT_ARGS="-c $(BR2_EXTERNAL)/board/adi/ev-sc598-som/nand.cfg"
+# BR2_TARGET_ROOTFS_EXT2 is not set
+BR2_TARGET_ROOTFS_CPIO=y
+BR2_TARGET_ROOTFS_CPIO_GZIP=y