Re: [PATCH 1/2] dt-bindings: crypto: qcom,prng: document SM8550

[neil . armstrong]

On 24/08/2023 10:40, Konrad Dybcio wrote:
> On 24.08.2023 08:37, Krzysztof Kozlowski wrote:
> > On 24/08/2023 01:32, Om Prakash Singh wrote:
> > > On 8/23/2023 1:25 PM, Neil Armstrong wrote:
> > > > Hi,
> > > >
> > > > On 23/08/2023 02:10, Om Prakash Singh wrote:
> > > > > On 8/22/2023 9:34 PM, Konrad Dybcio wrote:
> > > > > > On 22.08.2023 16:54, Om Prakash Singh wrote:
> > > > > > > PRNG Block on most of newer target from Qualcomm have some
> > > > > > > configuration where clock is configured by security firmware.
> > > > > > >
> > > > > > > Adding separate compatible string for each platform is overhead.
> > > > > > >
> > > > > > > We need to introduce common compatible string that can be used for
> > > > > > > all platforms with same configuration.
> > > > > > >
> > > > > > > I would suggest to use "qcom,rng-ee" for newer platform, dropping
> > > > > > > "p" also signifies it is not a Pseudo Random Number Generator.
> > > > > > Please reply inline and don't top-post.
> > > > > >
> > > > > >
> > > > > > Is this what you're trying to say?
> > > > > >
> > > > > > 1. sort out the clock requirements for designs where Linux manages it
> > > > > >      vs where the FW does so >
> > > > > > 2. introduce a new compatible for SoCs implementing a TRNG
> > > > > >
> > > > > > 3. for SoCs in 2., register the TRNG as a hwrng device
> > > > >
> > > > > Yes to all
> > > >
> > > > I can send a proposal, but that means writing a new driver for this
> > > > compatible in drivers/char/hw_random/ right ?
> > >
> > > We can add hwrng support in same driver like
> > > drivers/crypto/hisilicon/trng/trng.c
> > >
> > > As Krzysztof is suggesting we need to have platform specific compatible
> >
> > That's independent question
> >
> > > string, we can go with your change. for hwrng support I will send
> > > separate patches.
> >
> > Any bindings decision should be made now. We don't produce knowingly
> > incomplete bindings just to change them later. Therefore now you need to
> > decide whether you call it prng-ee or something else.
> Herbert already picked up the 8450 compatible last week or so.
> If we decide quickly, perhaps it can be reverted and substituted
> with the non-*P*RNG one. It would theoretically be an ABI break,
> but:
>
> a) it would be very very prompt
> b) the dts patch hasn't been merged so there are no users
>
> I'd be fine with that, not sure about the rest of you guys.

I'm fine for that aswell, this can be done quickly without the
hwrng part

I can quickly refresh this serie with :
1) introduce a new "qcom,trng" and move "qcom,sm8450-prng-ee" to "qcom,sm8450-trng"
2) add qcom,sm8550-prng-ee
3) add "qcom,trng"  to the driver compatible list

then afterwards, the hwrng part can be added in a separate serie.

Neil

> Konrad