Re: [PATCH 4/4] dt-bindings: firmware: Add Qualcomm UEFI Secure Application client

Krzysztof Kozlowski
2022-07-26T10:17:08Z

On 24/07/2022 00:49, Maximilian Luz wrote:
> Add bindings for the Qualcomm Trusted Execution Environment (TrEE) UEFI
> Secure application (uefisecapp) client.
>
> Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
> ---
> .../firmware/qcom,tee-uefisecapp.yaml | 38 +++++++++++++++++++
> MAINTAINERS | 1 +
> 2 files changed, 39 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/firmware/qcom,tee-uefisecapp.yaml
>
> diff --git a/Documentation/devicetree/bindings/firmware/qcom,tee-uefisecapp.yaml b/Documentation/devicetree/bindings/firmware/qcom,tee-uefisecapp.yaml
> new file mode 100644
> index 000000000000..9e5de1005d5c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/firmware/qcom,tee-uefisecapp.yaml
> @@ -0,0 +1,38 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/soc/qcom/qcom,rpmh-rsc.yaml#

Does not look like you tested the bindings. Please run `make
dt_binding_check` (see
Documentation/devicetree/bindings/writing-schema.rst for instructions).

> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm Trusted Execution Environment UEFI Secure Application
> +
> +maintainers:
> + - Maximilian Luz <luzmaximilian@gmail.com>
> +
> +description: |
> + Various Qualcomm SoCs do not allow direct access to UEFI variables. Instead,
> + these need to be accessed via the UEFI Secure Application (uefisecapp),
> + residing in the Trusted Execution Environment (TrEE). These bindings mark the
> + presence of uefisecapp and allow the respective client driver to load and
> + install efivar operations, providing the kernel with access to UEFI
> + variables.
> +
> +properties:
> + compatible:
> + const: qcom,tee-uefisecapp

Isn't this SoC-specific device? Generic compatibles are usually not
expected.

> +
> +required:
> + - compatible
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + firmware {
> + scm {
> + compatible = "qcom,scm-sc8180x", "qcom,scm";
> + };
> + tee-uefisecapp {
> + compatible = "qcom,tee-uefisecapp";

You did not model here any dependency on SCM. This is not full
description of the firmware/hardware.

Best regards,
Krzysztof