* Ingenic JZ4780 NAND/BCH This file documents the device tree bindings for NAND flash devices on the JZ4780. NAND devices are connected to the NEMC controller (described in memory-controllers/ingenic,jz4780-nemc.txt), and thus NAND device nodes must be children of the NEMC node. Required NAND controller device properties: - compatible: Should be set to "ingenic,jz4780-nand". - reg: For each bank with a NAND chip attached, should specify a bank number, an offset of 0 and a size of 0x1000000 (i.e. the whole NEMC bank). Optional NAND controller device properties: - ingenic,bch-controller: To make use of the hardware BCH controller, this property must contain a phandle for the BCH controller node. The required properties for this node are described below. If this is not specified, software BCH will be used instead. Optional children nodes: - Individual NAND chips are children of the NAND controller node. Required children node properties: - reg: An integer ranging from 1 to 6 representing the CS line to use. Optional children node properties: - nand-ecc-step-size: ECC block size in bytes. - nand-ecc-strength: ECC strength (max number of correctable bits). - nand-ecc-mode: String, operation mode of the NAND ecc mode. "hw" by default - nand-on-flash-bbt: boolean to enable on flash bbt option, if not present false - rb-gpios: GPIO specifier for the busy pin. - wp-gpios: GPIO specifier for the write protect pin. Optional child node of NAND chip nodes: - partitions: see Documentation/devicetree/bindings/mtd/partition.txt Example: nemc: nemc@13410000 { ... nandc: nand-controller@1 { compatible = "ingenic,jz4780-nand"; reg = <1 0 0x1000000>; /* Bank 1 */ #address-cells = <1>; #size-cells = <0>; ingenic,bch-controller = <&bch>; nand@1 { reg = <1>; nand-ecc-step-size = <1024>; nand-ecc-strength = <24>; nand-ecc-mode = "hw"; nand-on-flash-bbt; rb-gpios = <&gpa 20 GPIO_ACTIVE_LOW>; wp-gpios = <&gpf 22 GPIO_ACTIVE_LOW>; partitions { #address-cells = <2>; #size-cells = <2>; ... } }; }; }; The BCH controller is a separate SoC component used for error correction on NAND devices. The following is a description of the device properties for a BCH controller. Required BCH properties: - compatible: Should be set to "ingenic,jz4780-bch". - reg: Should specify the BCH controller registers location and length. - clocks: Clock for the BCH controller. Example: bch: bch@134d0000 { compatible = "ingenic,jz4780-bch"; reg = <0x134d0000 0x10000>; clocks = <&cgu JZ4780_CLK_BCH>; };