Re: [PATCH RFC linux] dt-bindings: nvmem: Add binding for U-Boot environment NVMEM provider

Rob Herring
2021-10-14T14:43:03Z

On Wed, Oct 13, 2021 at 6:20 PM Marek Behún <kabel@kernel.org> wrote:
>
> Add device tree bindings for U-Boot environment NVMEM provider.
>
> U-Boot environment can be stored at a specific offset of a MTD device,
> EEPROM, MMC, NAND or SATA device, on an UBI volume, or in a file on a
> filesystem.
>
> The environment can contain information such as device's MAC address,
> which should be used by the ethernet controller node.
>
> Signed-off-by: Marek Behún <kabel@kernel.org>
> ---
> .../bindings/nvmem/denx,u-boot-env.yaml | 88 +++++++++++++++++++
> include/dt-bindings/nvmem/u-boot-env.h | 18 ++++
> 2 files changed, 106 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/nvmem/denx,u-boot-env.yaml
> create mode 100644 include/dt-bindings/nvmem/u-boot-env.h
>
> diff --git a/Documentation/devicetree/bindings/nvmem/denx,u-boot-env.yaml b/Documentation/devicetree/bindings/nvmem/denx,u-boot-env.yaml
> new file mode 100644
> index 000000000000..56505c08e622
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/nvmem/denx,u-boot-env.yaml
> @@ -0,0 +1,88 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/nvmem/denx,u-boot-env.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: U-Boot environment NVMEM Device Tree Bindings
> +
> +maintainers:
> + - Marek Behún <kabel@kernel.org>
> +
> +description:
> + This binding represents U-Boot's environment NVMEM settings which can be
> + stored on a specific offset of an EEPROM, MMC, NAND or SATA device, or
> + an UBI volume, or in a file on a filesystem.
> +
> +properties:
> + compatible:
> + const: denx,u-boot-env

'u-boot' is a vendor prefix. Unless you are saying Denx owns u-boot...

> +
> + path:
> + description:
> + The path to the file containing the environment if on a filesystem.
> + $ref: /schemas/types.yaml#/definitions/string
> +
> +patternProperties:
> + "^[^=]+$":
> + type: object
> +
> + description:
> + This node represents one U-Boot environment variable, which is also one
> + NVMEM data cell.
> +
> + properties:
> + name:

'name' is already a property for every node, so this would collide. It
used to be in the dtb itself, but current revisions generate it from
the node name.

> + description:
> + If the variable name contains characters not allowed in device tree node
> + name, use this property to specify the name, otherwise the variable name
> + is equal to node name.
> + $ref: /schemas/types.yaml#/definitions/string
> +
> + type:

'type' is really too generic. Any given property name should have 1
meaning and data type.

But I expect based on other comments already, all this is going away anyways.

> + description:
> + Type of the variable. Since variables, even integers and MAC addresses,
> + are stored as strings in U-Boot environment, for proper conversion the
> + type needs to be specified. Use one of the U_BOOT_ENV_TYPE_* prefixed
> + definitions from include/dt-bindings/nvmem/u-boot-env.h.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 0
> + maximum: 5