Commit 04e9ab75 authored by Rafał Miłecki's avatar Rafał Miłecki Committed by Rob Herring

dt-bindings: mtd: convert "fixed-partitions" to the json-schema

This standardizes its documentation, allows validating with Makefile
checks and helps writing DTS files.

Noticeable changes:
1. Dropped "Partitions can be represented by sub-nodes of a flash
   device." as we also support subpartitions (don't have to be part of
   flash device node)
2. Dropped "to Linux" as bindings are meant to be os agnostic.
Signed-off-by: default avatarRafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20201210172352.31632-1-zajec5@gmail.comSigned-off-by: default avatarRob Herring <robh@kernel.org>
parent 60a2a8ff
......@@ -24,137 +24,10 @@ another partitioning method.
Available bindings are listed in the "partitions" subdirectory.
Fixed Partitions
================
Partitions can be represented by sub-nodes of a flash device. This can be used
on platforms which have strong conventions about which portions of a flash are
used for what purposes, but which don't use an on-flash partition table such
as RedBoot.
The partition table should be a subnode of the flash node and should be named
'partitions'. This node should have the following property:
- compatible : (required) must be "fixed-partitions"
Partitions are then defined in subnodes of the partitions node.
Deprecated: partitions defined in flash node
============================================
For backwards compatibility partitions as direct subnodes of the flash device are
supported. This use is discouraged.
NOTE: also for backwards compatibility, direct subnodes that have a compatible
string are not considered partitions, as they may be used for other bindings.
#address-cells & #size-cells must both be present in the partitions subnode of the
flash device. There are two valid values for both:
<1>: for partitions that require a single 32-bit cell to represent their
size/address (aka the value is below 4 GiB)
<2>: for partitions that require two 32-bit cells to represent their
size/address (aka the value is 4 GiB or greater).
Required properties:
- reg : The partition's offset and size within the flash
Optional properties:
- label : The label / name for this partition. If omitted, the label is taken
from the node name (excluding the unit address).
- read-only : This parameter, if present, is a hint to Linux that this
partition should only be mounted read-only. This is usually used for flash
partitions containing early-boot firmware images or data which should not be
clobbered.
- lock : Do not unlock the partition at initialization time (not supported on
all devices)
- slc-mode: This parameter, if present, allows one to emulate SLC mode on a
partition attached to an MLC NAND thus making this partition immune to
paired-pages corruptions
Examples:
flash@0 {
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <1>;
partition@0 {
label = "u-boot";
reg = <0x0000000 0x100000>;
read-only;
};
uimage@100000 {
reg = <0x0100000 0x200000>;
};
};
};
flash@1 {
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <2>;
/* a 4 GiB partition */
partition@0 {
label = "filesystem";
reg = <0x00000000 0x1 0x00000000>;
};
};
};
flash@2 {
partitions {
compatible = "fixed-partitions";
#address-cells = <2>;
#size-cells = <2>;
/* an 8 GiB partition */
partition@0 {
label = "filesystem #1";
reg = <0x0 0x00000000 0x2 0x00000000>;
};
/* a 4 GiB partition */
partition@200000000 {
label = "filesystem #2";
reg = <0x2 0x00000000 0x1 0x00000000>;
};
};
};
flash@3 {
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <1>;
partition@0 {
label = "bootloader";
reg = <0x000000 0x100000>;
read-only;
};
firmware@100000 {
label = "firmware";
reg = <0x100000 0xe00000>;
compatible = "brcm,trx";
};
calibration@f00000 {
label = "calibration";
reg = <0xf00000 0x100000>;
compatible = "fixed-partitions";
ranges = <0 0xf00000 0x100000>;
#address-cells = <1>;
#size-cells = <1>;
partition@0 {
label = "wifi0";
reg = <0x000000 0x080000>;
};
partition@80000 {
label = "wifi1";
reg = <0x080000 0x080000>;
};
};
};
};
# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/mtd/partitions/fixed-partitions.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Fixed partitions
description: |
This binding can be used on platforms which have strong conventions about
which portions of a flash are used for what purposes, but which don't use an
on-flash partition table such as RedBoot.
The partition table should be a node named "partitions". Partitions are then
defined as subnodes.
maintainers:
- Rafał Miłecki <rafal@milecki.pl>
properties:
compatible:
const: fixed-partitions
"#address-cells": true
"#size-cells": true
patternProperties:
"@[0-9a-f]+$":
description: node describing a single flash partition
type: object
properties:
reg:
description: partition's offset and size within the flash
maxItems: 1
label:
description: The label / name for this partition. If omitted, the label
is taken from the node name (excluding the unit address).
read-only:
description: This parameter, if present, is a hint that this partition
should only be mounted read-only. This is usually used for flash
partitions containing early-boot firmware images or data which should
not be clobbered.
type: boolean
lock:
description: Do not unlock the partition at initialization time (not
supported on all devices)
type: boolean
slc-mode:
description: This parameter, if present, allows one to emulate SLC mode
on a partition attached to an MLC NAND thus making this partition
immune to paired-pages corruptions
type: boolean
required:
- reg
required:
- "#address-cells"
- "#size-cells"
additionalProperties: true
examples:
- |
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <1>;
partition@0 {
label = "u-boot";
reg = <0x0000000 0x100000>;
read-only;
};
uimage@100000 {
reg = <0x0100000 0x200000>;
};
};
- |
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <2>;
/* a 4 GiB partition */
partition@0 {
label = "filesystem";
reg = <0x00000000 0x1 0x00000000>;
};
};
- |
partitions {
compatible = "fixed-partitions";
#address-cells = <2>;
#size-cells = <2>;
/* an 8 GiB partition */
partition@0 {
label = "filesystem #1";
reg = <0x0 0x00000000 0x2 0x00000000>;
};
/* a 4 GiB partition */
partition@200000000 {
label = "filesystem #2";
reg = <0x2 0x00000000 0x1 0x00000000>;
};
};
- |
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <1>;
partition@0 {
label = "bootloader";
reg = <0x000000 0x100000>;
read-only;
};
firmware@100000 {
compatible = "brcm,trx";
label = "firmware";
reg = <0x100000 0xe00000>;
};
calibration@f00000 {
compatible = "fixed-partitions";
label = "calibration";
reg = <0xf00000 0x100000>;
ranges = <0 0xf00000 0x100000>;
#address-cells = <1>;
#size-cells = <1>;
partition@0 {
label = "wifi0";
reg = <0x000000 0x080000>;
};
partition@80000 {
label = "wifi1";
reg = <0x080000 0x080000>;
};
};
};
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