Re: [PATCH 0/3] RK3576 Hardware RNG

Herbert Xu
2025-05-05T12:33:57Z

On Wed, Apr 30, 2025 at 06:16:33PM +0200, Nicolas Frattaroli wrote:
> Gee Nicolas, how come your mom lets you write two Rockchip HWRNG drivers
> in a year?
>
> In short, RK3576 (and RK3562 and RK3528) introduce another HWRNG IP. It
> actually has quite a few cool features, but I ignored the cool bits and
> went straight for the true entropy. Some of the cool bits someone else
> may wish to add in the future: AES-CTR PRNG that's regularly reseeded
> from the entropy, adjustments for oscillator and oscillator ring lengths
> to maximise entropy generation, automatic continuous quality checking of
> the produced entropy by the hardware itself, etc.
>
> In testing, it seems to produce about 2 mbit/s of high quality entropy
> on the RK3576 with its default settings when we read the TRNG entropy
> output directly. That's less than we'd get if we had the hardware use
> the PRNG to stretch it, but I've decided to leave that up to Linux's
> entropy pool implementation for now.
>
> RK3562 and RK3528 probably just need a compatible and a DTS node to
> enable it as well, but I don't have any RK3562/RK3528 boards to test
> this with, so it's not done in this series.
>
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
> ---
> Nicolas Frattaroli (3):
> dt-bindings: rng: rockchip,rk3588-rng: add rk3576-rng compatible
> hwrng: rockchip - add support for RK3576's RNG
> arm64: dts: rockchip: add RK3576 RNG node
>
> .../bindings/rng/rockchip,rk3588-rng.yaml | 5 +-
> arch/arm64/boot/dts/rockchip/rk3576.dtsi | 8 +++
> drivers/char/hw_random/rockchip-rng.c | 73 ++++++++++++++++++++++
> 3 files changed, 84 insertions(+), 2 deletions(-)
> ---
> base-commit: 4e0a9c660788594b5b49ac07f0fbdccd2218431e
> change-id: 20250429-rk3576-hwrng-8c308b5711ae
>
> Best regards,
> --
> Nicolas Frattaroli <nicolas.frattaroli@collabora.com>

Patches 1-2 applied. Thanks.
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
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