dt-bindings: mtd: Convert gpmi nand to json-schema

* 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,<chip>-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 {

	...

	};

};

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/mtd/gpmi-nand.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

title:  Freescale General-Purpose Media Interface (GPMI) binding

maintainers:

  - Han Xu <han.xu@nxp.com>

allOf:

  - $ref: "nand-controller.yaml"

description: |

  The GPMI nand controller provides an interface to control the NAND

  flash chips. The device tree may optionally contain sub-nodes

  describing partitions of the address space. See partition.txt for

  more detail.

properties:

  compatible:

    enum:

      - fsl,imx23-gpmi-nand

      - fsl,imx28-gpmi-nand

      - fsl,imx6q-gpmi-nand

      - fsl,imx6sx-gpmi-nand

      - fsl,imx7d-gpmi-nand

  reg:

    items:

      - description: Address and length of gpmi block.

      - description: Address and length of bch block.

  reg-names:

    items:

      - const: gpmi-nand

      - const: bch

  interrupts:

    maxItems: 1

  interrupt-names:

    const: bch

  dmas:

    maxItems: 1

  dma-names:

    const: rx-tx

  clocks:

    minItems: 1

    maxItems: 5

    items:

      - description: SoC gpmi io clock

      - description: SoC gpmi apb clock

      - description: SoC gpmi bch clock

      - description: SoC gpmi bch apb clock

      - description: SoC per1 bch clock

  clock-names:

    minItems: 1

    maxItems: 5

    items:

      - const: gpmi_io

      - const: gpmi_apb

      - const: gpmi_bch

      - const: gpmi_bch_apb

      - const: per1_bch

  fsl,use-minimum-ecc:

    type: boolean

    description: |

      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:

    type: boolean

    description: |

      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.

required:

  - compatible

  - reg

  - reg-names

  - interrupts

  - interrupt-names

  - clocks

  - clock-names

  - dmas

  - dma-names

unevaluatedProperties: false

examples:

  - |

    nand-controller@8000c000 {

        #address-cells = <1>;

        #size-cells = <0>;

        compatible = "fsl,imx28-gpmi-nand";

        reg = <0x8000c000 0x2000>, <0x8000a000 0x2000>;

        reg-names = "gpmi-nand", "bch";

        interrupts = <41>;

        interrupt-names = "bch";

        clocks = <&clks 50>;

        clock-names = "gpmi_io";

        dmas = <&dma_apbh 4>;

        dma-names = "rx-tx";

    };