Re: [PATCH 4/4] tpm: Add YAML schema for the TPM TIS I2C options

[Rob Herring]

On Mon, Apr 04, 2022 at 10:18:35AM +0200, Johannes Holland wrote:
> Add a YAML schema to support device tree bindings for the generic I2C
> physical layer. Refer to the TCG PC Client Platform TPM Profile (PTP)
> Specification for TPM 2.0 v1.04 Revision 14.

Bindings are for devices. A protocol layer does not make a device.

> 
> Signed-off-by: Johannes Holland <johannes.holland@xxxxxxxxxxxx>
> ---
>  .../bindings/security/tpm/tpm-tis-i2c.yaml    | 48 +++++++++++++++++++
>  1 file changed, 48 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm-tis-i2c.yaml

We already have a binding for I2C TPM. That one should be converted.

> 
> diff --git a/Documentation/devicetree/bindings/security/tpm/tpm-tis-i2c.yaml b/Documentation/devicetree/bindings/security/tpm/tpm-tis-i2c.yaml
> new file mode 100644
> index 000000000000..7948867ff3f7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/security/tpm/tpm-tis-i2c.yaml
> @@ -0,0 +1,48 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/security/tpm/tpm-tis-i2c.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: I2C PTP based TPM Device Tree Bindings
> +
> +maintainers:
> +  - Johannes Holland <johannes.holland@xxxxxxxxxxxx>
> +
> +description:
> +  Device Tree Bindings for I2C based Trusted Platform Module (TPM).
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          # Infineon's Trusted Platform Module (TPM) (SLB9673)
> +          - infineon,slb9673
> +          # Nuvoton's Trusted Platform Module (TPM) (NPCT75x)
> +          - nuvoton,npct75x

I see this is already used, but in general wildcards should not be used 
in device compatibles.

> +      - const: tcg,tpm-tis-i2c

Pretty sure I killed this off when originally reviewing the TPM I2C 
binding.

> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupt:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      tpm@2e {
> +        compatible = "infineon,slb9673", "nuvoton,npct75x", "tcg,tpm-tis-i2c";
> +        reg = <0x2e>;
> +      };
> +    };
> +...
> -- 
> 2.31.1.windows.1
> 
>