On 7/2/26 1:58 PM, Sumit Garg wrote:

From: Sumit Garg <redacted>

Qcom platforms has the legacy of using non-standard SCM calls
splintered over the various kernel drivers. These SCM calls aren't
compliant with the standard SMC calling conventions which is a
prerequisite to enable migration to the FF-A specifications from Arm.

OP-TEE as an alternative trusted OS to Qualcomm TEE (QTEE) can't
support these non-standard SCM calls. And even for newer architectures
using S-EL2 with Hafnium support, QTEE won't be able to support SCM
calls either with FF-A requirements coming in. And with both OP-TEE
and QTEE drivers well integrated in the TEE subsystem, it makes further
sense to reuse the TEE bus client drivers infrastructure.

The added benefit of TEE bus infrastructure is that there is support
for discoverable/enumerable services. With that client drivers don't
have to manually invoke a special SCM call to know the service status.

So enable the generic Peripheral Authentication Service (PAS) provided
by the firmware. It acts as the common layer with different TZ
backends plugged in whether it's an SCM implementation or a proper
TEE bus based PAS service implementation.

Reviewed-by: Mukesh Ojha <redacted>
Tested-by: Mukesh Ojha <redacted> # Lemans
Reviewed-by: Harshal Dev <redacted>
Tested-by: Vignesh Viswanathan <redacted> # IPQ9650
Signed-off-by: Sumit Garg <redacted>
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Reviewed-by: Konrad Dybcio <redacted>

Konrad