[PATCH v4 13/15] dt-bindings: crypto: ice: document the hwkm property

[Gaurav Kashyap]

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.

Signed-off-by: Gaurav Kashyap <quic_gaurkash@xxxxxxxxxxx>
Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
---
 .../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 09e43157cc71..6415d7be9b73 100644
--- a/Documentation/devicetree/bindings/crypto/qcom,inline-crypto-engine.yaml
+++ b/Documentation/devicetree/bindings/crypto/qcom,inline-crypto-engine.yaml
@@ -25,6 +25,16 @@ 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.
+
 required:
   - compatible
   - reg
-- 
2.43.0