Re: [PATCH v5 13/15] dt-bindings: crypto: ice: document the hwkm property

[Konrad Dybcio <konrad.dybcio@linaro.org>]

On 6/17/24 02:51, Gaurav Kashyap wrote:
> When Qualcomm's Inline Crypto Engine (ICE) contains Hardware
> Key Manager (HWKM), and the 'HWKM' mode is enabled, it
> supports wrapped keys. However, this also requires firmware
> support in Trustzone to work correctly, which may not be available
> on all chipsets. In the above scenario, ICE needs to support standard
> keys even though HWKM is integrated from a hardware perspective.
> 
> Introducing this property so that Hardware wrapped key support
> can be enabled/disabled from software based on chipset firmware,
> and not just based on hardware version.
> 
> Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
> Signed-off-by: Gaurav Kashyap <quic_gaurkash@quicinc.com>
> ---
>   .../bindings/crypto/qcom,inline-crypto-engine.yaml     | 10 ++++++++++
>   1 file changed, 10 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/crypto/qcom,inline-crypto-engine.yaml b/Documentation/devicetree/bindings/crypto/qcom,inline-crypto-engine.yaml
> index 0304f074cf08..0bb4d008f961 100644
> --- a/Documentation/devicetree/bindings/crypto/qcom,inline-crypto-engine.yaml
> +++ b/Documentation/devicetree/bindings/crypto/qcom,inline-crypto-engine.yaml
> @@ -27,6 +27,16 @@ properties:
>     clocks:
>       maxItems: 1
>   
> +  qcom,ice-use-hwkm:
> +    type: boolean
> +    description:
> +      Use the supported Hardware Key Manager (HWKM) in Qualcomm ICE
> +      to support wrapped keys. Having this entry helps scenarios where
> +      the ICE hardware supports HWKM, but the Trustzone firmware does
> +      not have the full capability to use this HWKM and support wrapped
> +      keys. Not having this entry enabled would make ICE function in
> +      non-HWKM mode supporting standard keys.

Just check if qcom_scm_derive_sw_secret is available instead

Konrad