Re: [RFC PATCH 0/3] PM / clock_ops: allow to specify custom pm_clk_notifier callback

From: Geert Uytterhoeven
Date: Wed Sep 17 2014 - 11:03:13 EST


Hi Grygorii,

On Tue, Sep 9, 2014 at 3:41 PM, Grygorii Strashko
<grygorii.strashko@xxxxxx> wrote:
>> Since you're essentially gutting clock_ops, have you considered
>> migrating to genpd and having your own pm_domain ops that manage your clocks?
>
> Yes. I've thought about using genpd. But:
> - PM domain is not merged in 3.17 and I don't know if it will be merged in 3.18 :(
> http://www.spinics.net/lists/arm-kernel/msg357003.html

Let's wait and see...

> - To switch using PM domains I will need to create PM domain node PER EACH device,
> (if I understand PM domain bindings right). For example:
>
> +power_netcp: power-controller@0 {
> + compatible = "keystone,power-controller";
> + #power-domain-cells = <0>;
> + clocks = <&clkcpgmac>, <&clkpa>, <&chipclk12>;
> + };
>
> netcp: netcp@2090000 {
> reg = <0x2620110 0x8>;
> + power-domains = <&power_netcp>;
> ...
> }

I think you can have one power-controller, and add the clocks and
power-domains properties to the individual device nodes.

Then the power-controller driver can use the attach callback
introduced in "[PATCH/RFC v2 04/12] PM / Domains: Add genpd attach/detach
callbacks" (https://lkml.org/lkml/2014/9/16/429) to set up the clocks?

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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