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Diffstat (limited to 'Documentation/devicetree/bindings/power/power_domain.txt')
-rw-r--r-- | Documentation/devicetree/bindings/power/power_domain.txt | 112 |
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diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt new file mode 100644 index 000000000..08497ef26 --- /dev/null +++ b/Documentation/devicetree/bindings/power/power_domain.txt @@ -0,0 +1,112 @@ +* Generic PM domains + +System on chip designs are often divided into multiple PM domains that can be +used for power gating of selected IP blocks for power saving by reduced leakage +current. + +This device tree binding can be used to bind PM domain consumer devices with +their PM domains provided by PM domain providers. A PM domain provider can be +represented by any node in the device tree and can provide one or more PM +domains. A consumer node can refer to the provider by a phandle and a set of +phandle arguments (so called PM domain specifiers) of length specified by the +#power-domain-cells property in the PM domain provider node. + +==PM domain providers== + +See power-domain.yaml. + +==PM domain consumers== + +Required properties: + - power-domains : A list of PM domain specifiers, as defined by bindings of + the power controller that is the PM domain provider. + +Optional properties: + - power-domain-names : A list of power domain name strings sorted in the same + order as the power-domains property. Consumers drivers will use + power-domain-names to match power domains with power-domains + specifiers. + +Example: + + leaky-device@12350000 { + compatible = "foo,i-leak-current"; + reg = <0x12350000 0x1000>; + power-domains = <&power 0>; + power-domain-names = "io"; + }; + + leaky-device@12351000 { + compatible = "foo,i-leak-current"; + reg = <0x12351000 0x1000>; + power-domains = <&power 0>, <&power 1> ; + power-domain-names = "io", "clk"; + }; + +The first example 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". +In the second example the consumer device are partitioned across two PM domains, +the first with index 0 and the second with index 1, of a power controller that +is represented by a node with the label "power". + +Optional properties: +- required-opps: This contains phandle to an OPP node in another device's OPP + table. It may contain an array of phandles, where each phandle points to an + OPP of a different device. It should not contain multiple phandles to the OPP + nodes in the same OPP table. This specifies the minimum required OPP of the + device(s), whose OPP's phandle is present in this property, for the + functioning of the current device at the current OPP (where this property is + present). + +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>; + }; + }; + + power: power-controller@12340000 { + compatible = "foo,power-controller"; + reg = <0x12340000 0x1000>; + #power-domain-cells = <1>; + operating-points-v2 = <&domain0_opp_table>, <&domain1_opp_table>; + }; + + leaky-device0@12350000 { + compatible = "foo,i-leak-current"; + reg = <0x12350000 0x1000>; + power-domains = <&power 0>; + required-opps = <&domain0_opp_0>; + }; + + leaky-device1@12350000 { + compatible = "foo,i-leak-current"; + reg = <0x12350000 0x1000>; + power-domains = <&power 1>; + required-opps = <&domain1_opp_1>; + }; + +[1]. Documentation/devicetree/bindings/power/domain-idle-state.yaml |