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Diffstat (limited to 'Documentation/devicetree/bindings/mtd/gpio-control-nand.txt')
-rw-r--r-- | Documentation/devicetree/bindings/mtd/gpio-control-nand.txt | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt b/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt new file mode 100644 index 000000000..af8915b41 --- /dev/null +++ b/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt @@ -0,0 +1,47 @@ +GPIO assisted NAND flash + +The GPIO assisted NAND flash uses a memory mapped interface to +read/write the NAND commands and data and GPIO pins for the control +signals. + +Required properties: +- compatible : "gpio-control-nand" +- reg : should specify localbus chip select and size used for the chip. The + resource describes the data bus connected to the NAND flash and all accesses + are made in native endianness. +- #address-cells, #size-cells : Must be present if the device has sub-nodes + representing partitions. +- gpios : Specifies the GPIO pins to control the NAND device. The order of + GPIO references is: RDY, nCE, ALE, CLE, and an optional nWP. + +Optional properties: +- bank-width : Width (in bytes) of the device. If not present, the width + defaults to 1 byte. +- chip-delay : chip dependent delay for transferring data from array to + read registers (tR). If not present then a default of 20us is used. +- gpio-control-nand,io-sync-reg : A 64-bit physical address for a read + location used to guard against bus reordering with regards to accesses to + the GPIO's and the NAND flash data bus. If present, then after changing + GPIO state and before and after command byte writes, this register will be + read to ensure that the GPIO accesses have completed. + +The device tree may optionally contain sub-nodes describing partitions of the +address space. See partition.txt for more detail. + +Examples: + +gpio-nand@1,0 { + compatible = "gpio-control-nand"; + reg = <1 0x0000 0x2>; + #address-cells = <1>; + #size-cells = <1>; + gpios = <&banka 1 0>, /* RDY */ + <&banka 2 0>, /* nCE */ + <&banka 3 0>, /* ALE */ + <&banka 4 0>, /* CLE */ + <0>; /* nWP */ + + partition@0 { + ... + }; +}; |