Re: [PATCH 1/3] dt: Add DT bindings documentation for SUNXI Security System

On Saturday, May 24, 2014 at 09:51:59 PM, Tomasz Figa wrote:
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Why sun7i-a20 ? Is the crypto unit different in other sunxi chips ? Can
that not be described by DT props ?

A widely used convention is to define compatible strings after first
SoCs on which particular IP blocks appear. It is quite common among IP
blocks for which there is no well defined versioning scheme.

Well yeah, that's fine. But in this case, "sun7i" is the entire group of
CPUs manufactured by AW. I find that information redundant, the
"allwinner,a20- crypto" would suffice. But I wonder if that IP block
might have appeared even earlier ? Or if it is CPU family specific, thus
"allwinner,sun7i-crypto" would be a better string ?

I'm not aware of Allwinner naming schemes too much, so please correct me
if I'm wrong, but if A20 implies sun7i, then "allwinner,a20-crypto"
would be better indeed.

True.

Whether it was really the first SoC is another thing. Obviously this
needs to be checked, although it isn't really that important. For this
particular naming scheme you need to specify all the SoCs for which
given compatible string can be used for this IP anyway, because there is
usually no other source of information about this available (except
directly comparing two datasheets...).

Better get the DT stuff correctly right from the start. That's why I'm asking 
what chips contains the IP block, so we can guess the right name.

Best regards,
Marek Vasut