Re: [RFC V7 2/2] OPP: Allow "opp-hz" and "opp-microvolt" to contain magic values

From: Ulf Hansson
Date: Tue Nov 28 2017 - 11:15:06 EST


On 31 October 2017 at 13:47, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
> On some platforms the exact frequency or voltage may be hidden from the
> OS by the firmware. Allow such configurations to pass magic values in
> the "opp-hz" or the "opp-microvolt" properties, which should be
> interpreted in a platform dependent way.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

This seems like a reasonable extension to me!

Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>

Kind regards
Uffe

> ---
> Documentation/devicetree/bindings/opp/opp.txt | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt
> index 203e09fe7698..9c5056fb120f 100644
> --- a/Documentation/devicetree/bindings/opp/opp.txt
> +++ b/Documentation/devicetree/bindings/opp/opp.txt
> @@ -166,6 +166,12 @@ properties.
> "power-domains" property. Also, either all or none of the OPP nodes in an OPP
> table should have it set.
>
> +
> +On some platforms the exact frequency or voltage may be hidden from the OS by
> +the firmware and the "opp-hz" or the "opp-microvolt" properties may contain
> +magic values that represent the frequency or voltage in a firmware dependent
> +way, for example an index of an array in the firmware.
> +
> Example 1: Single cluster Dual-core ARM cortex A9, switch DVFS states together.
>
> / {
> --
> 2.15.0.rc1.236.g92ea95045093
>