On Fri, Jan 23, 2015 at 12:39:14PM +0100, Lucas Stach wrote:
- Required properties:
- opp-khz: Frequency in kHz
- opp-microvolt: voltage in micro Volts
Each OPP voltage should be defined by the triplet of minimum, nominal/typical, maximum. This lets you specify exact tolerances in each direction and should cover most use-cases.
IMHO it would make sense to just define opp-microvolt as an array of those 3 values, so the DT doesn't get bloated with a lot more properties.
A typical value for a CPU could then look like this: opp-microvolt = <800000 850000 1100000>
I tend to agree that this is clearer. It might be nice to have variants for specifying directly as a percentage but I don't think it's really worth the complexity.
For devices without any tolerance you can just specify the same value three times and be done with it: opp-microvolt = <900000 900000 900000>
If we change the binding to be typ/min/max rather than min/typ/max then we could also do this by allowing either one or three values to be specified. That might be more worth the complexity especially given...
- Optional properties:
- turbo-mode: Marks the volt-freq pair as turbo pair.
- status: Marks the node enabled/disabled.
- voltage-tolerance: Specify the CPU voltage tolerance in percentage.
Please let's drop this.
DT bindings are supposed to be stable, this means the code should accept old bindings and they should be documented as deprecated.