[PATCH] powerpc, 460gt: Add 460gt as compatible in the check for 460ex-compatible crypto

Segher Boessenkool segher at kernel.crashing.org
Fri Jun 24 12:14:07 EST 2011


>>> -       if (of_find_compatible_node(NULL, NULL, 
>>> "amcc,ppc460ex-crypto")) {
>>> +       if (of_find_compatible_node(NULL, NULL, 
>>> "amcc,ppc460ex-crypto") ||
>>> +           of_find_compatible_node(NULL, NULL, 
>>> "amcc,ppc460gt-crypto")) {
>>
>> If the device is actually compatible, the device tree node should 
>> claim
>> it is, and you do not need this code change.
>
> That was actually my first instinct, however I tried to follow the
> current convention in the glacier and canyonlands DTS files, which is
> to set every device compatible to 460gt or 460ex, depending on the
> processor. Many of the devices are identical between the two, since
> they are variations of the same SoC, so which is the preferred method?
> Follow the device tree convention and add the compatibility check in
> the driver,

That is not the convention.

> or alter the device trees? I'll send another patch if it's
> the latter.

You say

   compatible = "amcc,ppc460gt-crypto", "amcc,ppc460ex-crypto";

So, a unique name for the actual device first, followed by the name of
what it is compatible to.  The driver for 460ex-crypto will then work
without any changes, but it can also do some 460gt-specific workarounds
or enhancements; or you could even have a totally separate driver for
the 460gt-crypto (you'll have to arrange for it to be used preferably
then).

You should document this 460gt-crypto binding, btw (a single line in
the 460ex-crypto binding doc will do).


Segher



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