Re: [PATCH] arm64: dts: ti: k3-am62p-j722s: add rng node

Michael Walle
2025-04-01T06:20:08Z

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Hi Udit,

> >>> --- a/arch/arm64/boot/dts/ti/k3-am62p-j722s-common-main.dtsi
> >>> [..]
> >> For completeness , this is ok to add this node but should be kept disabled
> > Shouldn't it be "reserved" then, see [1].
>
> yes, should be reserved.
>
> With marking status as reserved.
>
> Please use Reviewed-by: Udit Kumar <u-kumar1@ti.com>

Thanks.

> >> similar to
> >>
> >> https://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi#L662
> > j784s4, j721e and j721s2 have them enabled. What is the rule here?
>
> J784s4, j721e and j721s2 SOCs has two TRNG blocks,
>
> example for j721e, one is used by kernel [0] and another by optee [1].
>
>
> >
> > You also disable the hwrng in optee in your evm according to [2]:
> > CFG_WITH_SOFTWARE_PRNG=y
>
> We are planning to use this hardware block by secure firmware.
>
> Therefore request not to use by optee as well

How will you be able to access the RNG from linux and u-boot? I'm
asking because I'll need it in u-boot for the lwip stack and the
HTTPS protocol.

-michael

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