
Hi Rob, could you re-review my patch as I provided answers (see below), please?
On 3.03.2022 09:32, Rafał Miłecki wrote:
On 2.03.2022 22:59, Rob Herring wrote:
On Thu, Feb 17, 2022 at 11:24:48AM +0100, Rafał Miłecki wrote:
From: Rafał Miłecki rafal@milecki.pl
UBI is often used on embedded devices to store UBI volumes with device configuration / calibration data. Such volumes may need to be documented and referenced for proper boot & setup.
Some examples:
- U-Boot environment variables
- Device calibration data
- Default setup (e.g. initial password)
Signed-off-by: Rafał Miłecki rafal@milecki.pl
.../bindings/mtd/partitions/ubi.yaml | 67 +++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 Documentation/devicetree/bindings/mtd/partitions/ubi.yaml
diff --git a/Documentation/devicetree/bindings/mtd/partitions/ubi.yaml b/Documentation/devicetree/bindings/mtd/partitions/ubi.yaml new file mode 100644 index 000000000000..cd081f06d4cb --- /dev/null +++ b/Documentation/devicetree/bindings/mtd/partitions/ubi.yaml @@ -0,0 +1,67 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/mtd/partitions/ubi.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml#
+title: UBI (Unsorted Block Images) device
+description: | + UBI is a layer providing logical volumes (consisting of logical blocks) on top + of raw flash devices. It deals with low-level flash issues (bit-flips, bad + physical eraseblocks, wearing) providing a reliable data storage.
+ UBI device is built and stored in a single flash partition.
+ Some (usually embedded) devices use UBI volumes of specific names or indexes + to store setup / configuration data. This binding allows describing such + volumes so they can be identified and referenced by consumers.
+maintainers: + - Rafał Miłecki rafal@milecki.pl
+allOf: + - $ref: partition.yaml#
+properties: + compatible: + const: ubi
+patternProperties: + "^volume-[0-9a-f]+$": + type: object + description: UBI volume + properties: + volume-name: + $ref: /schemas/types.yaml#/definitions/string + volume-id: + $ref: /schemas/types.yaml#/definitions/uint32 + anyOf: + - required: + - volume-name + - required: + - volume-id
+unevaluatedProperties: false
+examples: + - | + partitions { + compatible = "fixed-partitions"; + #address-cells = <1>; + #size-cells = <1>;
+ partition@0 { + compatible = "ubi"; + reg = <0x0000000 0x1000000>; + label = "filesystem";
+ env: volume-0 { + volume-name = "u-boot-env";
Why not do 'compatible = "u-boot,env";' to align with normal partitions?
I mean to reserve "compatible" for describing UBI volume content.
If I manage to get [PATCH V3] dt-bindings: nvmem: add U-Boot environment variables binding https://patchwork.ozlabs.org/project/devicetree-bindings/patch/2022022813125... accepted, it'll allow me to later work on something like:
env: volume-0 { compatible = "u-boot,env"; volume-name = "u-boot-env"; };
(I believe) I'll need (in the final shape) two properties:
- One for describing UBI volume ("compatible")
- One for identifying UBI volume ("volume-name" / "volume-id")
It's similar design to the "compatible" vs. "reg" in IO hw blocks.
Or 'label'?
I could replace "volume-name" with "label" but someone once told me that:
'label' is supposed to correspond to a sticker on a port or something human identifiable
;) https://patchwork.ozlabs.org/comment/2812214/
So I don't want to abuse "label" here.
We have enough ways to identify things, I don't think we need another.
+ };
+ calibration: volume-1 {
Are 0 and 1 meaningful or just made up indexing?
Made up indexing. I need unique nodenames but @[0-9a-f] doesn't appply here.
+ volume-id = <99>; + }; + };
+ };
2.34.1