Re: [RFC PATCH v2 4/5] dt-bindings: block: Generalize and introduce property for partitions

Rob Herring
2024-09-26T14:03:52Z

On Wed, Sep 25, 2024 at 11:45:24PM +0200, Christian Marangi wrote:
> Generalize property from MTD partitions schema and introduce property for
> block partitions defined in OF.
>
> Partition schema for block devices is a reduced schema of the MTD as
> only a few property are supported for it. (reg, label and read-only)
>
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> ---
> .../bindings/block/partitions/partition.yaml | 33 +++++++++++++++++++
> .../bindings/block/partitions/partitions.yaml | 27 +++++++++++++++
> .../bindings/mtd/partitions/partition.yaml | 10 ++----
> 3 files changed, 62 insertions(+), 8 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/block/partitions/partition.yaml
> create mode 100644 Documentation/devicetree/bindings/block/partitions/partitions.yaml

Partitions are partitions. We don't need them defined in both mtd and
block. Could perhaps move them to bindings/partitions/, but that's not
really worth it in my opinion. Just use and add to what's in mtd.

>
> diff --git a/Documentation/devicetree/bindings/block/partitions/partition.yaml b/Documentation/devicetree/bindings/block/partitions/partition.yaml
> new file mode 100644
> index 000000000000..b9b1d8139e56
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/block/partitions/partition.yaml
> @@ -0,0 +1,33 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/block/partitions/partition.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Partition
> +
> +description: |

Don't need '|' if no formatting.

> + This binding describes a single flash partition. Each partition must have its
> + relative offset and size specified. Depending on partition function extra
> + properties can be used.
> +
> +maintainers:
> + - Christian Marangi <ansuelsmth@gmail.com>
> +
> +properties:
> + reg:
> + description: partition's offset and size within the flash (in sector
> + block, 512byte)
> + maxItems: 1
> +
> + label:
> + description: The label / name for this partition.
> +
> + 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
> +
> +additionalProperties: true
> diff --git a/Documentation/devicetree/bindings/block/partitions/partitions.yaml b/Documentation/devicetree/bindings/block/partitions/partitions.yaml
> new file mode 100644
> index 000000000000..9c161aac364d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/block/partitions/partitions.yaml
> @@ -0,0 +1,27 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/block/partitions/partitions.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Partitions
> +
> +description: |
> + This binding is generic and describes the content of the partitions container
> + node.
> +
> +maintainers:
> + - Christian Marangi <ansuelsmth@gmail.com>
> +
> +properties:
> + '#address-cells':
> + enum: [1, 2]
> +
> + '#size-cells':
> + enum: [1, 2]

Like *all* other 'partitions' nodes, you need a compatible to say what
kind of partitions you have. It's conceivable that some vendor invented
their own scheme just like MTD devices.

As I said before, this is just 'fixed-partitions'. If some properties
aren't supported, that's fine. All the 'align' properties are for
flashing tools and aren't supported in Linux.

Rob