Re: [PATCH v2 1/3] dt-bindings: spmi: Add generic SPMI NVMEM

[Rob Herring <robh@kernel.org>]

On Thu, Apr 17, 2025 at 10:14:49PM +0200, Sasha Finkelstein wrote:
> Add bindings for exposing SPMI registers as NVMEM cells
> 
> Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
> ---
>  .../devicetree/bindings/nvmem/spmi-nvmem.yaml      | 54 ++++++++++++++++++++++
>  MAINTAINERS                                        |  1 +
>  2 files changed, 55 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/nvmem/spmi-nvmem.yaml b/Documentation/devicetree/bindings/nvmem/spmi-nvmem.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..d16b27128f97b5d38fb6ddb5109c70cda5e2ee15
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/nvmem/spmi-nvmem.yaml
> @@ -0,0 +1,54 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/nvmem/spmi-nvmem.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Generic SPMI NVMEM

What makes this generic?

A generic driver is great, but "generic" or "simple" bindings are 
generally a mistake.

> +
> +description: Exports a series of SPMI registers as NVMEM cells
> +
> +maintainers:
> +  - Sasha Finkelstein <fnkl.kernel@gmail.com>
> +
> +allOf:
> +  - $ref: nvmem.yaml#
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          - apple,maverick-pmic
> +          - apple,sera-pmic
> +          - apple,stowe-pmic
> +      - const: spmi-nvmem

What happens when there's some other feature of the PMIC exposed that's 
not nvmem?

> +
> +  reg:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/spmi/spmi.h>
> +
> +    pmic@f {
> +        compatible = "apple,maverick-pmic", "spmi-nvmem";
> +        reg = <0xf SPMI_USID>;
> +
> +        nvmem-layout {
> +            compatible = "fixed-layout";
> +            #address-cells = <1>;
> +            #size-cells = <1>;
> +
> +            boot_stage: boot-stage@6001 {
> +                reg = <0x6001 0x1>;
> +            };
> +        };
> +    };
> +
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 96b82704950184bd71623ff41fc4df31e4c7fe87..e7b2d0df81b387ba5398957131971588dc7b89dc 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2277,6 +2277,7 @@ F:	Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
>  F:	Documentation/devicetree/bindings/net/bluetooth/brcm,bcm4377-bluetooth.yaml
>  F:	Documentation/devicetree/bindings/nvme/apple,nvme-ans.yaml
>  F:	Documentation/devicetree/bindings/nvmem/apple,efuses.yaml
> +F:	Documentation/devicetree/bindings/nvmem/spmi-nvmem.yaml
>  F:	Documentation/devicetree/bindings/pci/apple,pcie.yaml
>  F:	Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
>  F:	Documentation/devicetree/bindings/power/apple*
> 
> -- 
> 2.49.0
>