[PATCH] PM / Domains: Fix compatible for domain idle state

[Ulf Hansson]

On 10 November 2016 at 20:58, Rob Herring <robh at kernel.org> wrote:
>
> On Mon, Nov 07, 2016 at 12:14:28PM +0100, Ulf Hansson wrote:
> > On 3 November 2016 at 22:54, Lina Iyer <lina.iyer at linaro.org> wrote:
> > > Re-using idle state definition provided by arm,idle-state for domain
> > > idle states creates a lot of confusion and limits further evolution of
> > > the domain idle definition. To keep things clear and simple, define a
> > > idle states for domain using a new compatible "domain-idle-state".
> > >
> > > Fix existing PM domains code to look for the newly defined compatible.
> > >
> > > Cc: <devicetree at vger.kernel.org>
> > > Cc: Rob Herring <robh at kernel.org>
> > > Signed-off-by: Lina Iyer <lina.iyer at linaro.org>
> > > ---
> > >  .../bindings/power/domain-idle-state.txt           | 33 ++++++++++++++++++++++
> > >  .../devicetree/bindings/power/power_domain.txt     |  8 +++---
> > >  drivers/base/power/domain.c                        |  2 +-
> > >  3 files changed, 38 insertions(+), 5 deletions(-)
> > >  create mode 100644 Documentation/devicetree/bindings/power/domain-idle-state.txt
> > >
> > > diff --git a/Documentation/devicetree/bindings/power/domain-idle-state.txt b/Documentation/devicetree/bindings/power/domain-idle-state.txt
> > > new file mode 100644
> > > index 0000000..eefc7ed
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/power/domain-idle-state.txt
> > > @@ -0,0 +1,33 @@
> > > +PM Domain Idle State Node:
> > > +
> > > +A domain idle state node represents the state parameters that will be used to
> > > +select the state when there are no active components in the domain.
> > > +
> > > +The state node has the following parameters -
> > > +
> > > +- compatible:
> > > +       Usage: Required
> > > +       Value type: <string>
> > > +       Definition: Must be "domain-idle-state".
> > > +
> > > +- entry-latency-us
> > > +       Usage: Required
> > > +       Value type: <prop-encoded-array>
> > > +       Definition: u32 value representing worst case latency in
> > > +                   microseconds required to enter the idle state.
> > > +                   The exit-latency-us duration may be guaranteed
> > > +                   only after entry-latency-us has passed.
> >
> > As we anyway are going to change this, why not use an u64 and have the
> > value in ns instead of us?
>
> I can't imagine that you would need more resolution or range. For times
> less than 1us, s/w and register access times are going to dominate the
> time.

Yep.

>
>
> Unless there is a real need, I'd keep alignment with the existing
> binding.

Agree!

Kind regards
Uffe