Sudeep Holla <sudeep.holla@xxxxxxx> writes: > On 28/04/17 21:48, Rob Herring wrote: >> On Wed, Apr 26, 2017 at 04:27:05PM +0530, Viresh Kumar wrote: >>> Power-domains need to express their active states in DT and the devices >>> within the power-domain need to express their dependency on those active >>> states. The power-domains can use the OPP tables without any >>> modifications to the bindings. >>> >>> Add a new property "power-domain-opp", which will contain phandle to the >>> OPP node of the parent power domain. This is required for devices which >>> have dependency on the configured active state of the power domain for >>> their working. >>> >>> For some platforms the actual frequency and voltages of the power >>> domains are managed by the firmware and are so hidden from the high >>> level operating system. The "opp-hz" property is relaxed a bit to >>> contain indexes instead of actual frequency values to support such >>> platforms. >>> >>> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> >>> --- >>> Documentation/devicetree/bindings/opp/opp.txt | 74 ++++++++++++++++++++++++++- >>> 1 file changed, 73 insertions(+), 1 deletion(-) >>> >>> diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt >>> index 63725498bd20..6e30cae2a936 100644 >>> --- a/Documentation/devicetree/bindings/opp/opp.txt >>> +++ b/Documentation/devicetree/bindings/opp/opp.txt >>> @@ -77,7 +77,10 @@ This defines voltage-current-frequency combinations along with other related >>> properties. >>> >>> Required properties: >>> -- opp-hz: Frequency in Hz, expressed as a 64-bit big-endian integer. >>> +- opp-hz: Frequency in Hz, expressed as a 64-bit big-endian integer. In some >>> + cases the exact frequency in Hz may be hidden from the OS by the firmware and >>> + this field may contain values that represent the frequency in a firmware >>> + dependent way, for example an index of an array in the firmware. >> >> Not really sure OPP binding makes sense here. What about all the other >> properties. We expose voltage, but not freq? >> > > I completely agree with that and I have been pushing this to be > represented as just regulators[0]. Mark B seem to dislike that > idea [1] And Mark is right, because what's being described is not (simply) a voltage regultor. While it might be "just" voltage on some SoCs (for now), it is clearly about performance (a.k.a. OPP) on others. Kevin -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
