Re: [PATCH 3/3] hwrng: msm - Add support for prng v2

On 18-06-18, 11:21, Bjorn Andersson wrote:

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.

I did think about that, in those case a DT change would do the trick by
pointing to the TZ EE and loading v1 driver but then is DT board sepcific
or SoC specific, I think latter :(

Can we detect the model..?

quoted

 	rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);

@@ -154,6 +161,9 @@ static int msm_rng_probe(struct platform_device *pdev)
 		return PTR_ERR(rng->clk);
 
 	rng->hwrng = &msm_rng;
+	version = (unsigned long)of_device_get_match_data(&pdev->dev);

If this is "version" then please make it 1 or 2, if you agree with
Stephen's suggestion of omitting the initialization of init I think this
would be better as 0/1 and the variable named "skip_init".

ok will do

-- 
~Vinod