* Freescale General-Purpose Media Interface (GPMI) The GPMI nand controller provides an interface to control the NAND flash chips. Required properties: - compatible : should be "fsl,-gpmi-nand", chip can be: * imx23 * imx28 * imx6q * imx6sx * imx7d - reg : should contain registers location and length for gpmi and bch. - reg-names: Should contain the reg names "gpmi-nand" and "bch" - interrupts : BCH interrupt number. - interrupt-names : Should be "bch". - dmas: DMA specifier, consisting of a phandle to DMA controller node and GPMI DMA channel ID. Refer to dma.txt and fsl-mxs-dma.txt for details. - dma-names: Must be "rx-tx". - clocks : clocks phandle and clock specifier corresponding to each clock specified in clock-names. - clock-names : The "gpmi_io" clock is always required. Which clocks are exactly required depends on chip: * imx23/imx28 : "gpmi_io" * imx6q/sx : "gpmi_io", "gpmi_apb", "gpmi_bch", "gpmi_bch_apb", "per1_bch" * imx7d : "gpmi_io", "gpmi_bch_apb" Optional properties: - nand-on-flash-bbt: boolean to enable on flash bbt option if not present false - fsl,use-minimum-ecc: Protect this NAND flash with the minimum ECC strength required. The required ECC strength is automatically discoverable for some flash (e.g., according to the ONFI standard). However, note that if this strength is not discoverable or this property is not enabled, the software may chooses an implementation-defined ECC scheme. - fsl,no-blockmark-swap: Don't swap the bad block marker from the OOB area with the byte in the data area but rely on the flash based BBT for identifying bad blocks. NOTE: this is only valid in conjunction with 'nand-on-flash-bbt'. WARNING: on i.MX28 blockmark swapping cannot be disabled for the BootROM in the FCB. Thus, partitions written from Linux with this feature turned on may not be accessible by the BootROM code. - nand-ecc-strength: integer representing the number of bits to correct per ECC step. Needs to be a multiple of 2. - nand-ecc-step-size: integer representing the number of data bytes that are covered by a single ECC step. The driver supports 512 and 1024. The device tree may optionally contain sub-nodes describing partitions of the address space. See partition.txt for more detail. Examples: gpmi-nand@8000c000 { compatible = "fsl,imx28-gpmi-nand"; #address-cells = <1>; #size-cells = <1>; reg = <0x8000c000 2000>, <0x8000a000 2000>; reg-names = "gpmi-nand", "bch"; interrupts = <41>; interrupt-names = "bch"; dmas = <&dma_apbh 4>; dma-names = "rx-tx"; partition@0 { ... }; };