Re: [PATCH v4 1/2] ARM: keystone: pm: switch to use generic pm domains

From: Geert Uytterhoeven
Date: Thu Nov 20 2014 - 16:54:15 EST


On Thu, Nov 20, 2014 at 10:48 PM, Kevin Hilman <khilman@xxxxxxxxxx> wrote:
>>> So what exactly are we talking about with "PM" clocks, and why are they
>>> "special" when it comes to PM domains? IOW, why are the clocks to be
>>> managed during PM domain transitions for a given device any different
>>> than the clocks that need to be managed for a runtime suspend/resume (or
>>> system suspend/resume) sequence for the same device?
>>
>> (Speaking for my case, shmobile)
>>
>> They're not. The clocks to be managed during PM domain transitions are the
>> same as the clocks that need to be managed for a runtime suspend/resume
>> (or system suspend/resume) sequence.
>>
>> The special thing is that this is more a platform than a driver thing: the same
>> module may have a "PM/functional" clock (that is documented to enable/disable
>> the module) on one Soc, but noet on another.
>
> So why isn't the presence or absence of the clock described in the .dtsi
> for the SoC instead of being handled by special PM domain logic?

It is. Cfr. the presence/absence of clocks for renesas,rcar-gpio nodes.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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