The NAND chips in MTD have a bunch of generic options that are needed in a device tree. Add a YAML schemas for those. Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx> --- Changes from v1: - Removed free form text binding - Enhanced properties descriptions - Fixed the SPDX license tag - Added minimums for nand-ecc-strength and nand-ecc-step-size - Removed Boris from the maintainers --- Documentation/devicetree/bindings/mtd/nand-controller.yaml | 141 +++++++- Documentation/devicetree/bindings/mtd/nand.txt | 75 +---- 2 files changed, 141 insertions(+), 75 deletions(-) create mode 100644 Documentation/devicetree/bindings/mtd/nand-controller.yaml delete mode 100644 Documentation/devicetree/bindings/mtd/nand.txt diff --git a/Documentation/devicetree/bindings/mtd/nand-controller.yaml b/Documentation/devicetree/bindings/mtd/nand-controller.yaml new file mode 100644 index 000000000000..ebc7833ffc0c --- /dev/null +++ b/Documentation/devicetree/bindings/mtd/nand-controller.yaml @@ -0,0 +1,141 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/mtd/nand-controller.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: NAND Chip and NAND Controller Generic Binding + +maintainers: + - Miquel Raynal <miquel.raynal@xxxxxxxxxxx> + - Richard Weinberger <richard@xxxxxx> + +description: | + The NAND controller should be represented with its own DT node, and + all NAND chips attached to this controller should be defined as + children nodes of the NAND controller. This representation should be + enforced even for simple controllers supporting only one chip. + + The ECC strength and ECC step size properties define the user + desires in terms of correction capability of a controller. Together, + they request the ECC engine to correct {strength} bit errors per + {size} bytes. + + The interpretation of these parameters is implementation-defined, so + not all implementations must support all possible + combinations. However, implementations are encouraged to further + specify the value(s) they support. + +properties: + $nodename: + pattern: "^nand-controller(@.*)?" + + "#address-cells": + const: 1 + + "#size-cells": + const: 0 + + ranges: true + +patternProperties: + "^nand@[a-z0-9]$": + properties: + reg: + description: + Contains the native Ready/Busy IDs. + + nand-ecc-mode: + allOf: + - $ref: /schemas/types.yaml#/definitions/string + - enum: [ none, soft, hw, hw_syndrome, hw_oob_first, on-die ] + description: + Desired ECC engine, either hardware (most of the time + embedded in the NAND controller) or software correction + (Linux will handle the calculations). soft_bch is deprecated + and should be replaced by soft and nand-ecc-algo. + + nand-ecc-algo: + allOf: + - $ref: /schemas/types.yaml#/definitions/string + - enum: [ hamming, bch, rs ] + description: + Desired ECC algorithm. + + nand-bus-width: + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + - enum: [ 8, 16 ] + - default: 8 + description: + Bus width to the NAND chip + + nand-on-flash-bbt: + $ref: /schemas/types.yaml#/definitions/flag + description: + With this property, the OS will search the device for a Bad + Block Table (BBT). If not found, it will create one, reserve + a few blocks at the end of the device to store it and update + it as the device ages. Otherwise, the out-of-band area of a + few pages of all the blocks will be scanned at boot time to + find Bad Block Markers (BBM). These markers will help to + build a volatile BBT in RAM. + + nand-ecc-strength: + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 1 + description: + Maximum number of bits that can be corrected per ECC step. + + nand-ecc-step-size: + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 1 + description: + Number of data bytes covered by a single ECC step. + + nand-ecc-maximize: + $ref: /schemas/types.yaml#/definitions/flag + description: + Whether or not the ECC strength should be maximized. The + maximum ECC strength is both controller and chip + dependent. The ECC engine has to select the ECC config + providing the best strength and taking the OOB area size + constraint into account. This is particularly useful when + only the in-band area is used by the upper layers, and you + want to make your NAND as reliable as possible. + + nand-is-boot-medium: + $ref: /schemas/types.yaml#/definitions/flag + description: + Whether or not the NAND chip is a boot medium. Drivers might + use this information to select ECC algorithms supported by + the boot ROM or similar restrictions. + + nand-rb: + $ref: /schemas/types.yaml#/definitions/uint32-array + description: + Contains the native Ready/Busy IDs. + + required: + - reg + +required: + - "#address-cells" + - "#size-cells" + +examples: + - | + nand-controller { + #address-cells = <1>; + #size-cells = <0>; + + /* controller specific properties */ + + nand@0 { + reg = <0>; + nand-ecc-mode = "soft"; + nand-ecc-algo = "bch"; + + /* controller specific properties */ + }; + }; diff --git a/Documentation/devicetree/bindings/mtd/nand.txt b/Documentation/devicetree/bindings/mtd/nand.txt deleted file mode 100644 index e949c778e983..000000000000 --- a/Documentation/devicetree/bindings/mtd/nand.txt +++ /dev/null @@ -1,75 +0,0 @@ -* NAND chip and NAND controller generic binding - -NAND controller/NAND chip representation: - -The NAND controller should be represented with its own DT node, and all -NAND chips attached to this controller should be defined as children nodes -of the NAND controller. This representation should be enforced even for -simple controllers supporting only one chip. - -Mandatory NAND controller properties: -- #address-cells: depends on your controller. Should at least be 1 to - encode the CS line id. -- #size-cells: depends on your controller. Put zero unless you need a - mapping between CS lines and dedicated memory regions - -Optional NAND controller properties -- ranges: only needed if you need to define a mapping between CS lines and - memory regions - -Optional NAND chip properties: - -- nand-ecc-mode : String, operation mode of the NAND ecc mode. - Supported values are: "none", "soft", "hw", "hw_syndrome", - "hw_oob_first", "on-die". - Deprecated values: - "soft_bch": use "soft" and nand-ecc-algo instead -- nand-ecc-algo: string, algorithm of NAND ECC. - Valid values are: "hamming", "bch", "rs". -- nand-bus-width : 8 or 16 bus width if not present 8 -- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false - -- nand-ecc-strength: integer representing the number of bits to correct - per ECC step. - -- nand-ecc-step-size: integer representing the number of data bytes - that are covered by a single ECC step. - -- nand-ecc-maximize: boolean used to specify that you want to maximize ECC - strength. The maximum ECC strength is both controller and - chip dependent. The controller side has to select the ECC - config providing the best strength and taking the OOB area - size constraint into account. - This is particularly useful when only the in-band area is - used by the upper layers, and you want to make your NAND - as reliable as possible. -- nand-is-boot-medium: Whether the NAND chip is a boot medium. Drivers might use - this information to select ECC algorithms supported by - the boot ROM or similar restrictions. - -- nand-rb: shall contain the native Ready/Busy ids. - -The ECC strength and ECC step size properties define the correction capability -of a controller. Together, they say a controller can correct "{strength} bit -errors per {size} bytes". - -The interpretation of these parameters is implementation-defined, so not all -implementations must support all possible combinations. However, implementations -are encouraged to further specify the value(s) they support. - -Example: - - nand-controller { - #address-cells = <1>; - #size-cells = <0>; - - /* controller specific properties */ - - nand@0 { - reg = <0>; - nand-ecc-mode = "soft"; - nand-ecc-algo = "bch"; - - /* controller specific properties */ - }; - }; base-commit: 1244df4693747552c8efba995f4ebc3b247536cf -- git-series 0.9.1
