From: mike.turquette@linaro.org (Mike Turquette)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC] cpufreq: Add bindings for CPU clock sharing topology
Date: Wed, 23 Jul 2014 17:33:14 -0700 [thread overview]
Message-ID: <20140724003314.6419.51564@quantum> (raw)
In-Reply-To: <CAKohpok-C+JCebjJkZExx6EjBctoyJF7fV71Vjj7bi1TAdXrFQ@mail.gmail.com>
Quoting Viresh Kumar (2014-07-20 05:07:32)
> On 19 July 2014 20:54, Santosh Shilimkar <santosh.shilimkar@ti.com> wrote:
> > Sorry for jumping late
>
> No, you aren't late. Its just 2 days old thread :)
>
> > but one of the point I was raising as part of your
> > other series was to extend the CPU topology bindings to cover the voltage
> > domain information which is probably what is really needed to let the
> > CPUfreq extract the information. Not sure if it was already discussed.
>
> Not it wasn't.
>
> > After all the CPU clocks, cluster, clock-gating, power domains are pretty much
> > related. So instead of having new binding for CPUFreq, I was wondering whether
> > we can extend the CPU topology binding information to include missing information.
> > Scheduler work anyway needs that information.
> >
> > Ref: Documentation/devicetree/bindings/arm/topology.txt
> >
> > Does that make sense ?
>
> Yeah it does, but I am not sure what exactly the bindings should look then.
> So, the most basic step could be moving the new bindings to topology.txt
> and name clock-master to dvfs-master.
>
> What else?
If we're going to model the hardware then the binding should not use the
CPU phandles in "clock-master" or "dvfs-master". The correct thing to
model for a given CPU is which clock consumes. It's not accurate to say
that one CPU is the "master", at least not in this context.
A previous approach tried to compare struct clk pointers, which is a bad
idea since those are just cookies and should not be deref'd by drivers.
However a similar approach would be to compare the phandle, right?
Regards,
Mike
>
> If its going to be much controversial then we *can* go for just dvfs bindings
> for now and then update them later.
>
> Doesn't make sense? :)
next prev parent reply other threads:[~2014-07-24 0:33 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-18 5:35 [RFC] cpufreq: Add bindings for CPU clock sharing topology Viresh Kumar
2014-07-18 6:17 ` Olof Johansson
2014-07-18 6:40 ` Viresh Kumar
2014-07-18 21:52 ` Olof Johansson
2014-07-19 14:46 ` Viresh Kumar
2014-07-19 15:24 ` Santosh Shilimkar
2014-07-20 12:07 ` Viresh Kumar
2014-07-21 13:40 ` Santosh Shilimkar
2014-07-24 0:33 ` Mike Turquette [this message]
2014-07-24 2:24 ` Rob Herring
2014-07-24 10:39 ` Viresh Kumar
2014-07-25 20:02 ` Mike Turquette
2014-08-25 7:05 ` Viresh Kumar
2014-07-21 17:00 ` Rob Herring
2014-07-23 4:55 ` Viresh Kumar
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