Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property

From	Sudeep Holla <sudeep.holla@arm.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property
Date	2017-05-03 13:40 +0200
Message-ID	<tD0Ns-4I5-3@gated-at.bofh.it> (permalink)
References	<tAsPT-197-3@gated-at.bofh.it> <tAsPV-197-35@gated-at.bofh.it> <tBkZY-4ij-13@gated-at.bofh.it>
Organization	ARM

Show all headers | View raw


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@linaro.org>
>> ---
>>  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]

-- 
Regards,
Sudeep

[0] http://www.spinics.net/lists/devicetree/msg174725.html
[1] http://www.spinics.net/lists/devicetree/msg175113.html

Thread

[PATCH V6 0/9] PM / Domains: Implement domain performance states Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-26 13:00 +0200
  [PATCH V6 8/9] PM / Domain: Add struct device to genpd Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-26 13:00 +0200
  [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-26 13:00 +0200
    Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Rob Herring <robh@kernel.org> - 2017-04-28 22:50 +0200
      Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Sudeep Holla <sudeep.holla@arm.com> - 2017-05-03 13:40 +0200
        Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Kevin Hilman <khilman@baylibre.com> - 2017-05-06 23:50 +0200
          Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Sudeep Holla <sudeep.holla@arm.com> - 2017-05-08 15:50 +0200
        Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-05-08 09:20 +0200
          Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Sudeep Holla <sudeep.holla@arm.com> - 2017-05-08 16:00 +0200
            Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-05-09 07:30 +0200
      Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Kevin Hilman <khilman@baylibre.com> - 2017-05-06 23:50 +0200
        Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-05-08 06:20 +0200
          Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Rajendra Nayak <rnayak@codeaurora.org> - 2017-05-08 07:40 +0200
            Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-05-08 09:20 +0200
  [PATCH V6 7/9] PM / domain: Register PM QOS performance notifier Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-26 13:00 +0200
  [PATCH V6 5/9] PM / OPP: Add support to parse "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-26 13:00 +0200

csiph-web