[PATCH v2 2/4] PM / OPP: Initialize OPP table from device tree

Shawn Guo shawn.guo at linaro.org
Mon Aug 6 13:19:19 EST 2012


On Sun, Aug 05, 2012 at 09:50:32PM -0500, Rob Herring wrote:
> > +Properties:
> > +- operating-points: An array of 3-tuples items, and each item consists
> 
> 3 tuples?
> 
It's the case of v1, and I forgot updating it.  Thanks for spotting it.

> > +  of frequency and voltage like <freq-kHz vol-uV>.
> > +	freq: clock frequency in kHz
> > +	vol: voltage in microvolt
> 
> Although maybe 3 fields would be good for a flags field? I'm concerned
> it's a pretty generic name and not very future proof. What about
> transition times? Not sure how you would represent that as it probably
> depends on which points you are changing between rather than a property
> of the opp.
> 
This is a binding for OPP, which does not define transition times.

As for cpufreq, we only need to represent a possible maximum transition
latency.  The driver will ask regulator subsystem for voltage latency,
while the clock latency is defined in DT. 

> I think this whole function can be written more concisely. Just iterate
> over the property and avoid the intermediate array allocation.
> 
I'm not sure about that, since directly iterating over the property
means we have to take care of all these sanity checks done in API
of_property_read_u32_array().

-- 
Regards,
Shawn



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