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Message-ID: <CAPDyKFp_6VD6+7XJGy4oWOf+YQH4Ah6Q7BfmQsuz2OYp4KGjzA@mail.gmail.com>
Date: Tue, 28 Nov 2017 16:50:32 +0100
From: Ulf Hansson <ulf.hansson@...aro.org>
To: Viresh Kumar <viresh.kumar@...aro.org>
Cc: Kevin Hilman <khilman@...nel.org>,
Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
Stephen Boyd <sboyd@...eaurora.org>,
"Rafael J. Wysocki" <rjw@...ysocki.net>,
"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
Vincent Guittot <vincent.guittot@...aro.org>,
Rob Herring <robh+dt@...nel.org>,
Rajendra Nayak <rnayak@...eaurora.org>,
Sudeep Holla <sudeep.holla@....com>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [RFC V7 1/2] OPP: Allow OPP table to be used for power-domains
On 31 October 2017 at 13:47, Viresh Kumar <viresh.kumar@...aro.org> wrote:
> Power-domains can also have their active states and this patch enhances
> the OPP binding to define those.
>
> The power domains can use the OPP bindings mostly as is. Though there
> are some changes required to support special cases:
>
> - Allow "operating-points-v2" to contain multiple phandles for power
> domain providers providing multiple domains.
>
> - A new property "power-domain-opp" is added for devices to specify the
> minimum required OPP of the master domain for the functioning of the
> device. We can add this property directly to device's node if the
> device has a fixed minimum OPP requirement from the master power
Please avoid the terminology "master power domain", it's confusing.
Instead use only "power domain". This applies to a couple of more
places of $subject patch, please fix those as well.
> domain. Or we can add this property to each OPP node of the device, if
> different OPP nodes have different minimum OPP requirement from the
> master power domain.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
> ---
> Documentation/devicetree/bindings/opp/opp.txt | 12 +++++
> .../devicetree/bindings/power/power_domain.txt | 62 ++++++++++++++++++++++
> 2 files changed, 74 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt
> index 9d733af26be7..203e09fe7698 100644
> --- a/Documentation/devicetree/bindings/opp/opp.txt
> +++ b/Documentation/devicetree/bindings/opp/opp.txt
> @@ -45,6 +45,11 @@ 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.
>
> +This can contain more than one phandle for power domain providers that provide
> +multiple power domains. That is, one phandle for each power domain. If only one
> +phandle is available, then the same OPP table will be used for all power domains
> +provided by the power domain provider.
> +
> If required, this can be extended for SoC vendor specific bindings. Such bindings
> should be documented as Documentation/devicetree/bindings/power/<vendor>-opp.txt
> and should have a compatible description like: "operating-points-v2-<vendor>".
> @@ -154,6 +159,13 @@ properties.
>
> - status: Marks the node enabled/disabled.
>
> +- power-domain-opp: This contains phandle to one of the OPP nodes of the master
> + power domain. This specifies the minimum required OPP of the master domain for
> + the functioning of the device in this OPP (where this property is present).
> + This property can only be set for a device if the device node contains the
> + "power-domains" property. Also, either all or none of the OPP nodes in an OPP
> + table should have it set.
> +
> Example 1: Single cluster Dual-core ARM cortex A9, switch DVFS states together.
>
> / {
> diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
> index 14bd9e945ff6..0d8608f2d133 100644
> --- a/Documentation/devicetree/bindings/power/power_domain.txt
> +++ b/Documentation/devicetree/bindings/power/power_domain.txt
> @@ -40,6 +40,12 @@ phandle arguments (so called PM domain specifiers) of length specified by the
> domain's idle states. In the absence of this property, the domain would be
> considered as capable of being powered-on or powered-off.
>
> +- operating-points-v2 : Phandles to the OPP tables of power domains provided by
> + a power domain provider. If the provider provides a single power domain only
> + or all the power domains provided by the provider have identical OPP tables,
> + then this shall contain a single phandle. Refer to ../opp/opp.txt for more
> + information.
> +
> Example:
>
> power: power-controller@...40000 {
> @@ -120,4 +126,60 @@ The node above defines a typical PM domain consumer device, which is located
> inside a PM domain with index 0 of a power controller represented by a node
> with the label "power".
>
> +Optional properties:
> +- power-domain-opp: This contains phandle to one of the OPP nodes of the master
> + power domain. This specifies the minimum required OPP of the master domain for
> + the functioning of the device. This property can only be set for a device, if
> + the device node contains the "power-domains" property.
> +
> +Example:
> +- OPP table for domain provider that provides two domains.
> +
> + domain0_opp_table: opp_table0 {
> + compatible = "operating-points-v2";
> +
> + domain0_opp_0: opp-1000000000 {
> + opp-hz = /bits/ 64 <1000000000>;
> + opp-microvolt = <975000 970000 985000>;
> + };
> + domain0_opp_1: opp-1100000000 {
> + opp-hz = /bits/ 64 <1100000000>;
> + opp-microvolt = <1000000 980000 1010000>;
> + };
> + };
> +
> + domain1_opp_table: opp_table1 {
> + compatible = "operating-points-v2";
> +
> + domain1_opp_0: opp-1200000000 {
> + opp-hz = /bits/ 64 <1200000000>;
> + opp-microvolt = <975000 970000 985000>;
> + };
> + domain1_opp_1: opp-1300000000 {
> + opp-hz = /bits/ 64 <1300000000>;
> + opp-microvolt = <1000000 980000 1010000>;
> + };
> + };
> +
> + parent: power-controller@...40000 {
> + compatible = "foo,power-controller";
> + reg = <0x12340000 0x1000>;
> + #power-domain-cells = <1>;
> + operating-points-v2 = <&domain0_opp_table>, <&domain1_opp_table>;
> + };
> +
> + leaky-device0@...50000 {
> + compatible = "foo,i-leak-current";
> + reg = <0x12350000 0x1000>;
> + power-domains = <&parent 0>;
> + power-domain-opp = <&domain0_opp_0>;
> + };
> +
> + leaky-device1@...50000 {
> + compatible = "foo,i-leak-current";
> + reg = <0x12350000 0x1000>;
> + power-domains = <&parent 1>;
> + power-domain-opp = <&domain1_opp_1>;
> + };
> +
> [1]. Documentation/devicetree/bindings/power/domain-idle-state.txt
> --
Besides the minor nitpick(s), this looks good to me. Feel free to add:
Reviewed-by: Ulf Hansson <ulf.hansson@...aro.org>
Kind regards
Uffe
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