mirror of
https://github.com/torvalds/linux.git
synced 2024-11-23 04:31:50 +00:00
dt-bindings: mtd: Add YAML schemas for the generic NAND options
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@bootlin.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
This commit is contained in:
Maxime Ripard
Miquel Raynal
parent
cf3bbe67be
commit
212e496935
143
Documentation/devicetree/bindings/mtd/nand-controller.yaml
Normal file
143
Documentation/devicetree/bindings/mtd/nand-controller.yaml
Normal file
@ -0,0 +1,143 @@
|
||||
# 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@bootlin.com>
|
||||
- Richard Weinberger <richard@nod.at>
|
||||
|
||||
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:
|
||||
$nodename:
|
||||
pattern: "^nand-controller(@.*)?"
|
||||
|
||||
"#address-cells":
|
||||
const: 1
|
||||
|
||||
"#size-cells":
|
||||
const: 0
|
||||
|
||||
ranges: true
|
||||
|
||||
patternProperties:
|
||||
"^nand@[a-f0-9]$":
|
||||
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:
|
||||
allOf:
|
||||
- $ref: /schemas/types.yaml#/definitions/uint32
|
||||
- minimum: 1
|
||||
description:
|
||||
Maximum number of bits that can be corrected per ECC step.
|
||||
|
||||
nand-ecc-step-size:
|
||||
allOf:
|
||||
- $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 */
|
||||
};
|
||||
};
|
||||
@ -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 */
|
||||
};
|
||||
};
|
||||
Loading…
Reference in New Issue
Block a user