Add SMI NAND driver

Signed-off-by: Luke Wren <wren6991@gmail.com>

Documentation/devicetree/bindings/mtd/brcm,bcm2835-smi-nand.txt

@@ -0,0 +1,42 @@
+* BCM2835 SMI NAND flash
+
+This driver is a shim between the BCM2835 SMI driver (SMI is a peripheral for
+talking to parallel register interfaces) and Linux's MTD layer.
+
+Required properties:
+- compatible: "brcm,bcm2835-smi-nand"
+- status: "okay"
+
+Optional properties:
+- partition@n, where n is an integer from a consecutive sequence starting at 0
+	- Difficult to store partition table on NAND device - normally put it
+	in the source code, kernel bootparams, or device tree (the best way!)
+	- Sub-properties:
+		- label: the partition name, as shown by mtdinfo /dev/mtd*
+		- reg: the size and offset of this partition.
+		- (optional) read-only: an empty property flagging as read only
+
+Example:
+
+nand: flash@0 {
+	compatible = "brcm,bcm2835-smi-nand";
+	status = "okay";
+
+	partition@0 {
+		label = "stage2";
+		// 128k
+		reg = <0 0x20000>;
+		read-only;
+	};
+	partition@1 {
+		label = "firmware";
+		// 16M
+		reg = <0x20000 0x1000000>;
+		read-only;
+	};
+	partition@2 {
+		label = "root";
+		// 2G
+		reg = <0x1020000 0x80000000>;
+	};
+};

arch/arm/boot/dts/overlays/Makefile

@@ -15,6 +15,7 @@ endif
 dtb-$(RPI_DT_OVERLAYS) += ads7846-overlay.dtb
 dtb-$(RPI_DT_OVERLAYS) += smi-overlay.dtb
 dtb-$(RPI_DT_OVERLAYS) += smi-dev-overlay.dtb
+dtb-$(RPI_DT_OVERLAYS) += smi-nand-overlay.dtb
 dtb-$(RPI_DT_OVERLAYS) += bmp085_i2c-sensor-overlay.dtb
 dtb-$(RPI_DT_OVERLAYS) += dht11-overlay.dtb
 dtb-$(RPI_DT_OVERLAYS) += enc28j60-overlay.dtb

arch/arm/boot/dts/overlays/smi-nand-overlay.dts

@@ -0,0 +1,69 @@
+// Description: Overlay to enable NAND flash through
+// the secondary memory interface
+// Author:	Luke Wren
+
+/dts-v1/;
+/plugin/;
+
+/{
+	compatible = "brcm,bcm2708";
+
+	fragment@0 {
+		target = <&smi>;
+		__overlay__ {
+			pinctrl-names = "default";
+			pinctrl-0 = <&smi_pins>;
+			status = "okay";
+		};
+	};
+
+	fragment@1 {
+		target = <&soc>;
+		__overlay__ {
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			nand: flash@0 {
+				compatible = "brcm,bcm2835-smi-nand";
+				smi_handle = <&smi>;
+				#address-cells = <1>;
+				#size-cells = <1>;
+				status = "okay";
+
+				partition@0 {
+					label = "stage2";
+					// 128k
+					reg = <0 0x20000>;
+					read-only;
+				};
+				partition@1 {
+					label = "firmware";
+					// 16M
+					reg = <0x20000 0x1000000>;
+					read-only;
+				};
+				partition@2 {
+					label = "root";
+					// 2G (will need to use 64 bit for >=4G)
+					reg = <0x1020000 0x80000000>;
+				};
+			};
+		};
+	};
+
+	fragment@2 {
+		target = <&gpio>;
+		__overlay__ {
+			smi_pins: smi_pins {
+				brcm,pins = <0 1 2 3 4 5 6 7 8 9 10 11
+					12 13 14 15>;
+				/* Alt 1: SMI */
+				brcm,function = <5 5 5 5 5 5 5 5 5 5 5
+					5 5 5 5 5>;
+				/* /CS, /WE and /OE are pulled high, as they are
+				   generally active low signals */
+				brcm,pull = <2 2 2 2 2 2 2 2 0 0 0 0 0 0 0 0>;
+			};
+		};
+	};
+};

arch/arm/configs/bcm2709_defconfig

@@ -392,6 +392,10 @@ CONFIG_DEVTMPFS=y
 CONFIG_DEVTMPFS_MOUNT=y
 CONFIG_DMA_CMA=y
 CONFIG_CMA_SIZE_MBYTES=5
+CONFIG_MTD=m
+CONFIG_MTD_BLOCK=m
+CONFIG_MTD_NAND=m
+CONFIG_MTD_UBI=m
 CONFIG_ZRAM=m
 CONFIG_ZRAM_LZ4_COMPRESS=y
 CONFIG_BLK_DEV_LOOP=y
@@ -1142,6 +1146,9 @@ CONFIG_CONFIGFS_FS=y
 CONFIG_ECRYPT_FS=m
 CONFIG_HFS_FS=m
 CONFIG_HFSPLUS_FS=m
+CONFIG_JFFS2_FS=m
+CONFIG_JFFS2_SUMMARY=y
+CONFIG_UBIFS_FS=m
 CONFIG_SQUASHFS=m
 CONFIG_SQUASHFS_XATTR=y
 CONFIG_SQUASHFS_LZO=y

arch/arm/configs/bcmrpi_defconfig

@@ -385,6 +385,10 @@ CONFIG_DEVTMPFS=y
 CONFIG_DEVTMPFS_MOUNT=y
 CONFIG_DMA_CMA=y
 CONFIG_CMA_SIZE_MBYTES=5
+CONFIG_MTD=m
+CONFIG_MTD_BLOCK=m
+CONFIG_MTD_NAND=m
+CONFIG_MTD_UBI=m
 CONFIG_ZRAM=m
 CONFIG_ZRAM_LZ4_COMPRESS=y
 CONFIG_BLK_DEV_LOOP=y
@@ -1135,6 +1139,9 @@ CONFIG_CONFIGFS_FS=y
 CONFIG_ECRYPT_FS=m
 CONFIG_HFS_FS=m
 CONFIG_HFSPLUS_FS=m
+CONFIG_JFFS2_FS=m
+CONFIG_JFFS2_SUMMARY=y
+CONFIG_UBIFS_FS=m
 CONFIG_SQUASHFS=m
 CONFIG_SQUASHFS_XATTR=y
 CONFIG_SQUASHFS_LZO=y

drivers/mtd/nand/Kconfig

@@ -41,6 +41,13 @@ config MTD_SM_COMMON
 	tristate
 	default n
 
+config MTD_NAND_BCM2835_SMI
+        tristate "Use Broadcom's Secondary Memory Interface as a NAND controller (BCM283x)"
+        depends on (MACH_BCM2708 || MACH_BCM2709 || ARCH_BCM2835) && BCM2835_SMI && MTD_NAND
+        default m
+        help
+	  Uses the BCM2835's SMI peripheral as a NAND controller.
+
 config MTD_NAND_DENALI
         tristate "Support Denali NAND controller"
         depends on HAS_DMA

drivers/mtd/nand/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_MTD_NAND_DENALI)		+= denali.o
 obj-$(CONFIG_MTD_NAND_DENALI_PCI)	+= denali_pci.o
 obj-$(CONFIG_MTD_NAND_DENALI_DT)	+= denali_dt.o
 obj-$(CONFIG_MTD_NAND_AU1550)		+= au1550nd.o
+obj-$(CONFIG_MTD_NAND_BCM2835_SMI)	+= bcm2835_smi_nand.o
 obj-$(CONFIG_MTD_NAND_BF5XX)		+= bf5xx_nand.o
 obj-$(CONFIG_MTD_NAND_S3C2410)		+= s3c2410.o
 obj-$(CONFIG_MTD_NAND_DAVINCI)		+= davinci_nand.o