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Commit 6f357de8 authored by Alex Smith's avatar Alex Smith Committed by Brian Norris
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doc: dt: mtd: new binding for jz4780-{nand,bch} 



Add DT bindings for NAND devices connected to the NEMC on JZ4780 SoCs,
as well as the hardware BCH controller, used by the jz4780_{nand,bch}
drivers.

Signed-off-by: default avatarAlex Smith <alex.smith@imgtec.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarHarvey Hunt <harvey.hunt@imgtec.com>
Acked-by: default avatarRob Herring <robh@kernel.org>
Reviewed-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent 33853ebd

Documentation/devicetree/bindings/mtd/ingenic,jz4780-nand.txt

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* 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>;

};