From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH V7 2/3] OPP: Allow multiple OPP tables to be passed via DT Date: Thu, 18 Jun 2015 08:20:34 +0530 Message-ID: <20150618025034.GB28820@linux> References: <263c128844f5a3c9280c8be71f6c9eb1869a5188.1433434659.git.viresh.kumar@linaro.org> <20150617133314.GB15153@linux> <55821F30.2090802@codeaurora.org> <20150618022543.GA28820@linux> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150618022543.GA28820@linux> Sender: linux-pm-owner@vger.kernel.org To: Stephen Boyd Cc: Rob Herring , Rafael Wysocki , "linaro-kernel@lists.linaro.org" , "linux-pm@vger.kernel.org" , Arnd Bergmann , Nishanth Menon , Mark Brown , Mike Turquette , Grant Likely , Olof Johansson , Sudeep Holla , "devicetree@vger.kernel.org" , Viswanath Puttagunta , Lucas Stach , Thomas Petazzoni , "linux-arm-kernel@lists.infradead.org" , Thomas Abraham , Abhilash Kesavan , Kevin Hilman , Santosh List-Id: devicetree@vger.kernel.org On 18-06-15, 07:55, Viresh Kumar wrote: > Why do you think so? For me the operating-points-v2-names property > will be present in CPU node (as there is no OPP node which can have > it) and so every CPU is free to choose what it wants to. So, I had something like this in mind: From: Viresh Kumar Date: Thu, 30 Apr 2015 17:38:00 +0530 Subject: [PATCH] OPP: Allow multiple OPP tables to be passed via DT On some platforms (Like Qualcomm's SoCs), it is not decided until runtime on what OPPs to use. The OPP tables can be fixed at compile time, but which table to use is found out only after reading some efuses (sort of an prom) and knowing characteristics of the SoC. To support such platform we need to pass multiple OPP tables per device and hardware should be able to choose one and only one table out of those. Update operating-points-v2 bindings to support that. Signed-off-by: Viresh Kumar --- Documentation/devicetree/bindings/power/opp.txt | 63 +++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/Documentation/devicetree/bindings/power/opp.txt b/Documentation/devicetree/bindings/power/opp.txt index 259bf00edf7d..72ccacaac9c9 100644 --- a/Documentation/devicetree/bindings/power/opp.txt +++ b/Documentation/devicetree/bindings/power/opp.txt @@ -45,10 +45,21 @@ Devices supporting OPPs must set their "operating-points-v2" property with phandle to a OPP table in their DT node. The OPP core will use this phandle to find the operating points for the device. +Devices may want to choose OPP tables at runtime and so can provide a list of +phandles here. But only *one* of them should be chosen at runtime. This must be +accompanied by a corresponding "operating-points-v2-names" property, to uniquely +identify the OPP tables. + If required, this can be extended for SoC vendor specfic bindings. Such bindings should be documented as Documentation/devicetree/bindings/power/-opp.txt and should have a compatible description like: "operating-points-v2-". +Optional properties: +- operating-points-v2-names: Names of OPP tables (required if multiple OPP + tables are present), to uniquely identify them. The same list must be present + for all the CPUs which are sharing clock/voltage rails and hence the OPP + tables. + * OPP Table Node This describes the OPPs belonging to a device. This node can have following @@ -63,11 +74,16 @@ This describes the OPPs belonging to a device. This node can have following reference an OPP. Optional properties: +- opp-name: Name of the OPP table, to uniquely identify it if more than one OPP + table is supplied in "operating-points-v2" property of device. + - opp-shared: Indicates that device nodes using this OPP Table Node's phandle switch their DVFS state together, i.e. they share clock/voltage/current lines. Missing property means devices have independent clock/voltage/current lines, but they share OPP tables. +- status: Marks the OPP table enabled/disabled. + * OPP Node @@ -396,3 +412,50 @@ Example 4: Handling multiple regulators }; }; }; + +Example 5: Multiple OPP tables + +/ { + cpus { + cpu@0 { + compatible = "arm,cortex-a7"; + ... + + cpu-supply = <&cpu_supply> + operating-points-v2 = <&cpu0_opp_table_slow>, <&cpu0_opp_table_fast>; + operating-points-v2-names = "slow", "fast"; + }; + }; + + cpu0_opp_table_slow: opp_table_slow { + compatible = "operating-points-v2"; + status = "okay"; + opp-shared; + + opp00 { + opp-hz = <600000000>; + ... + }; + + opp01 { + opp-hz = <800000000>; + ... + }; + }; + + cpu0_opp_table_fast: opp_table_fast { + compatible = "operating-points-v2"; + status = "okay"; + opp-shared; + + opp10 { + opp-hz = <1000000000>; + ... + }; + + opp11 { + opp-hz = <1100000000>; + ... + }; + }; +}; From mboxrd@z Thu Jan 1 00:00:00 1970 From: viresh.kumar@linaro.org (Viresh Kumar) Date: Thu, 18 Jun 2015 08:20:34 +0530 Subject: [PATCH V7 2/3] OPP: Allow multiple OPP tables to be passed via DT In-Reply-To: <20150618022543.GA28820@linux> References: <263c128844f5a3c9280c8be71f6c9eb1869a5188.1433434659.git.viresh.kumar@linaro.org> <20150617133314.GB15153@linux> <55821F30.2090802@codeaurora.org> <20150618022543.GA28820@linux> Message-ID: <20150618025034.GB28820@linux> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 18-06-15, 07:55, Viresh Kumar wrote: > Why do you think so? For me the operating-points-v2-names property > will be present in CPU node (as there is no OPP node which can have > it) and so every CPU is free to choose what it wants to. So, I had something like this in mind: From: Viresh Kumar Date: Thu, 30 Apr 2015 17:38:00 +0530 Subject: [PATCH] OPP: Allow multiple OPP tables to be passed via DT On some platforms (Like Qualcomm's SoCs), it is not decided until runtime on what OPPs to use. The OPP tables can be fixed at compile time, but which table to use is found out only after reading some efuses (sort of an prom) and knowing characteristics of the SoC. To support such platform we need to pass multiple OPP tables per device and hardware should be able to choose one and only one table out of those. Update operating-points-v2 bindings to support that. Signed-off-by: Viresh Kumar --- Documentation/devicetree/bindings/power/opp.txt | 63 +++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/Documentation/devicetree/bindings/power/opp.txt b/Documentation/devicetree/bindings/power/opp.txt index 259bf00edf7d..72ccacaac9c9 100644 --- a/Documentation/devicetree/bindings/power/opp.txt +++ b/Documentation/devicetree/bindings/power/opp.txt @@ -45,10 +45,21 @@ Devices supporting OPPs must set their "operating-points-v2" property with phandle to a OPP table in their DT node. The OPP core will use this phandle to find the operating points for the device. +Devices may want to choose OPP tables at runtime and so can provide a list of +phandles here. But only *one* of them should be chosen at runtime. This must be +accompanied by a corresponding "operating-points-v2-names" property, to uniquely +identify the OPP tables. + If required, this can be extended for SoC vendor specfic bindings. Such bindings should be documented as Documentation/devicetree/bindings/power/-opp.txt and should have a compatible description like: "operating-points-v2-". +Optional properties: +- operating-points-v2-names: Names of OPP tables (required if multiple OPP + tables are present), to uniquely identify them. The same list must be present + for all the CPUs which are sharing clock/voltage rails and hence the OPP + tables. + * OPP Table Node This describes the OPPs belonging to a device. This node can have following @@ -63,11 +74,16 @@ This describes the OPPs belonging to a device. This node can have following reference an OPP. Optional properties: +- opp-name: Name of the OPP table, to uniquely identify it if more than one OPP + table is supplied in "operating-points-v2" property of device. + - opp-shared: Indicates that device nodes using this OPP Table Node's phandle switch their DVFS state together, i.e. they share clock/voltage/current lines. Missing property means devices have independent clock/voltage/current lines, but they share OPP tables. +- status: Marks the OPP table enabled/disabled. + * OPP Node @@ -396,3 +412,50 @@ Example 4: Handling multiple regulators }; }; }; + +Example 5: Multiple OPP tables + +/ { + cpus { + cpu at 0 { + compatible = "arm,cortex-a7"; + ... + + cpu-supply = <&cpu_supply> + operating-points-v2 = <&cpu0_opp_table_slow>, <&cpu0_opp_table_fast>; + operating-points-v2-names = "slow", "fast"; + }; + }; + + cpu0_opp_table_slow: opp_table_slow { + compatible = "operating-points-v2"; + status = "okay"; + opp-shared; + + opp00 { + opp-hz = <600000000>; + ... + }; + + opp01 { + opp-hz = <800000000>; + ... + }; + }; + + cpu0_opp_table_fast: opp_table_fast { + compatible = "operating-points-v2"; + status = "okay"; + opp-shared; + + opp10 { + opp-hz = <1000000000>; + ... + }; + + opp11 { + opp-hz = <1100000000>; + ... + }; + }; +};