Re: [RESEND PATCH v16 4/4] ARM: dts: add the support power-domain node on RK3288 SoCs

Dmitry Torokhov
2015-08-25T23:48:00Z

On Tue, Aug 25, 2015 at 3:45 PM, Kevin Hilman <khilman@kernel.org> wrote:
> Doug Anderson <dianders@chromium.org> writes:
>
>> To put things in a
>> concrete way, for pd_vio we'd go through the entire device tree
>> ourselves and find all properties that look like "power-domains =
>> <&power RK3288_PD_VIO>;". We'd then find the parent of those
>> properties and look for a property named "clocks". We'd then iterate
>> over all those clocks and turn those on. Did I get that right?
>
> ... but you make it sound like more work than it is. The genpd already
> keeps a list of devices that refer to the power domain. In fact, the
> genpd 'attach' method can be platform-specific, so could be used to keep
> track of a list (or a subset) of clocks which are needed for reset.

That is not really workable: the attach and detach happen in
probe/remove path; if you do not have driver for the device you will
miss the clocks for it. And the quirk of this SoC is that we need to
turn all clocks during domain transition, regardless of whether there
is a driver for all devices.

Thanks.

--
Dmitry