D1 has a crypto engine similar to the one in other Allwinner SoCs.
Like H6, it has a separate MBUS clock gate.

It also requires the internal RC oscillator to be enabled for the TRNG
to return data, presumably because noise from the oscillator is used as
an entropy source. This is likely the case for earlier variants as well,
but it really only matters for H616 and newer SoCs, as H6 provides no
way to disable the internal oscillator.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>