Quoting Bjorn Andersson (2018-06-18 11:21:23)

On Mon 18 Jun 07:12 PDT 2018, Vinod Koul wrote:

quoted

Qcom 8996 and later chips support prng v2 where we need to only
implement .read callback for hwrng.

The hardware still needs initialization, so I think you should expand
this to mention that the initialization is moved to secure world and
that's the reason why we only implement read.

The question is what happens in projects with other security models.

Can we still read the PRNG_CONFIG register to see if it's already been
configured or not and then bail out if it isn't configured? That would
be better as long as we the system doesn't blow up if non-secure mode
tries to read the config register.