linux-kernel - Re: [PATCH 1/2] PM / Domains: Introduce domain-performance-state binding

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Date:   Tue, 29 Nov 2016 12:27:26 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Stephen Boyd <sboyd@...eaurora.org>
Cc:     Kevin Hilman <khilman@...libre.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Rob Herring <robh@...nel.org>,
        Rafael Wysocki <rjw@...ysocki.net>,
        "linaro-kernel@...ts.linaro.org" <linaro-kernel@...ts.linaro.org>,
        "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Mark Rutland <mark.rutland@....com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Lina Iyer <lina.iyer@...aro.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        Nayak Rajendra <rnayak@...eaurora.org>
Subject: Re: [PATCH 1/2] PM / Domains: Introduce domain-performance-state
 binding

On 28-11-16, 10:27, Stephen Boyd wrote:
> On 11/23/2016 08:40 PM, Viresh Kumar wrote:
> > But even in these cases we wouldn't be using the voltage values within the
> > kernel as we will be giving only a performance state to the M3 core, right?
> 
> Nope. In these cases we need to set a certain voltage and we do that by
> requesting it via the M3 core.

Don't we need something like this then ?

	parent: power-controller@...40000 {
		compatible = "foo,power-controller";
		reg = <0x12340000 0x1000>;
		#power-domain-cells = <0>;
		domain-performance-states = <&perf_state0>;
	};

	perf_state0: performance_states {
		pstate1: pstate@1 {
			index = <1>;
			/* Optional */
			microvolt = <970000 975000 985000>;
		};
		pstate2: pstate@2 {
			index = <2>;
			/* Optional */
			microvolt = <970000 975000 985000>;
		};
		pstate3: pstate@3 {
			index = <3>;
			/* Optional */
			microvolt = <970000 975000 985000>;
		};
	}

	cpus {
		cpu@0 {
			...
			power-domain = <&parent>;
			operating-points-v2 = <&cpu0_opp_table>;
		};
	};

	cpu0_opp_table: opp_table0 {
		compatible = "operating-points-v2";
		opp-shared;

		opp@...0000000 {
			opp-hz = /bits/ 64 <1000000000>;
			domain-performance-state = <&pstate1>;
		};
		opp@...0000000 {
			opp-hz = /bits/ 64 <1100000000>;
			domain-performance-state = <&pstate2>;
		};
		opp@...0000000 {
			opp-hz = /bits/ 64 <1200000000>;
			domain-performance-state = <&pstate3>;
		};
	};

-- 
viresh