Re: [PATCH V3 1/7] PM / Domains: Introduce "performance-states" binding

[Rob Herring]

On Fri, Feb 24, 2017 at 02:36:33PM +0530, Viresh Kumar wrote:
> Some platforms have the capability to configure the performance state of
> their power domains. The process of configuring the performance state is
> pretty much platform dependent and we may need to work with a wide range
> of configurables. For some platforms, like Qcom, it can be a positive
> integer value alone, while in other cases it can be voltage levels, etc.
> 
> The power-domain framework until now was only designed for the idle
> state management of the device and this needs to change in order to
> reuse the power-domain framework for active state management of the
> devices.
> 
> This patch adds DT bindings to describe the performance states of a
> power domain. The power domain node needs to contain a
> "performance-states" node, which itself is an array of per-state nodes.
> Each per-state node represents individual performance state of a device.
> Individual nodes are identified by their (mandatory) "reg" field. These
> nodes can also contain an optional "domain-microvolt" property. More
> properties can be added later on once we have more platforms using it.
> 
> If the consumers don't need the capability of switching to different
> domain performance states at runtime, then they can simply define their
> required domain performance state in their node directly using the
> "domain-performance-state" property. Otherwise the consumers can define
> their requirements with help of other infrastructure, for example the
> OPP table (added in a later commit).
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> Tested-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>
> ---
>  .../devicetree/bindings/power/power_domain.txt     | 67 ++++++++++++++++++++++
>  1 file changed, 67 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
> index 723e1ad937da..9be09e576f68 100644
> --- a/Documentation/devicetree/bindings/power/power_domain.txt
> +++ b/Documentation/devicetree/bindings/power/power_domain.txt
> @@ -38,6 +38,33 @@ 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.
>  
> +- performance-states : This describes the performance states of a PM domain.
> +  The performance-states node reflects the performance states of this PM domain
> +  and not the performance states of the devices or sub-domains in the PM domain.
> +  Sub domains can have their own performance states. Sub domains without their
> +  own performance states are governed by the performance states of the parent
> +  domain and the "domain-performance-state" properties of their consumers refer
> +  to the "reg" properties of the nodes in the parent domain.
> +
> +  Required properties of the performance-states node:
> +  - compatible: Allow performance states to express their compatibility. It
> +    should be: "domain-performance-state".
> +
> +  - nodes: The performance-states node should contain one or
> +    more nodes, each representing a supported performance state.
> +
> +    Required properties of the performance state nodes:
> +    - reg: A positive integer value representing the performance level
> +      associated with a performance state. The integer value '0' represents the
> +      lowest performance level and the highest value represents the highest
> +      performance level. The exact meaning and performance implications of
> +      individual values is left to be defined by the user platform.
> +
> +    Optional properties of performance state nodes:
> +    - domain-microvolt: voltage in micro Volts. A single regulator's voltage is
> +      specified with an array of size one or three.  Single entry is for target
> +      voltage and three entries are for <target min max> voltages.
> +
>  Example:
>  
>  	power: power-controller@12340000 {
> @@ -118,4 +145,44 @@ 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:
> +- domain-performance-state: A positive integer value representing the minimum
> +  performance level (of the parent domain) required by the consumer for its
> +  working. The integer value '0' represents the lowest performance level and the
> +  highest value represents the highest performance level. The value of
> +  domain-performance-state field should match one of the "reg" fields in the
> +  "performance-states" table of the parent power domain.
> +
> +
> +Example:
> +
> +	parent: power-controller@12340000 {
> +		compatible = "foo,power-controller";
> +		reg = <0x12340000 0x1000>;
> +		#power-domain-cells = <0>;
> +
> +		performance-states {
> +			compatible = "domain-performance-state";
> +			pstate@1 {
> +				reg = <1>;
> +				domain-microvolt = <970000 975000 985000>;

This doesn't look like "<target> <min> <max>".

With that fixed,

Acked-by: Rob Herring <robh@xxxxxxxxxx>


> +			};
> +			pstate@2 {
> +				reg = <2>;
> +				domain-microvolt = <1000000 1075000 1085000>;
> +			};
> +			pstate@3 {
> +				reg = <3>;
> +				domain-microvolt = <1100000 1175000 1185000>;
> +			};
> +		};
> +	};
> +
> +	leaky-device@12350000 {
> +		compatible = "foo,i-leak-current";
> +		reg = <0x12350000 0x1000>;
> +		power-domains = <&power 0>;
> +		domain-performance-state = <2>;
> +	};
> +
>  [1]. Documentation/devicetree/bindings/power/domain-idle-state.txt
> -- 
> 2.7.1.410.g6faf27b
>