1* Generic PM domains 2 3System on chip designs are often divided into multiple PM domains that can be 4used for power gating of selected IP blocks for power saving by reduced leakage 5current. 6 7This device tree binding can be used to bind PM domain consumer devices with 8their PM domains provided by PM domain providers. A PM domain provider can be 9represented by any node in the device tree and can provide one or more PM 10domains. A consumer node can refer to the provider by a phandle and a set of 11phandle arguments (so called PM domain specifiers) of length specified by the 12#power-domain-cells property in the PM domain provider node. 13 14==PM domain providers== 15 16See power-domain.yaml. 17 18==PM domain consumers== 19 20Required properties: 21 - power-domains : A list of PM domain specifiers, as defined by bindings of 22 the power controller that is the PM domain provider. 23 24Optional properties: 25 - power-domain-names : A list of power domain name strings sorted in the same 26 order as the power-domains property. Consumers drivers will use 27 power-domain-names to match power domains with power-domains 28 specifiers. 29 30Example: 31 32 leaky-device@12350000 { 33 compatible = "foo,i-leak-current"; 34 reg = <0x12350000 0x1000>; 35 power-domains = <&power 0>; 36 power-domain-names = "io"; 37 }; 38 39 leaky-device@12351000 { 40 compatible = "foo,i-leak-current"; 41 reg = <0x12351000 0x1000>; 42 power-domains = <&power 0>, <&power 1> ; 43 power-domain-names = "io", "clk"; 44 }; 45 46The first example above defines a typical PM domain consumer device, which is 47located inside a PM domain with index 0 of a power controller represented by a 48node with the label "power". 49In the second example the consumer device are partitioned across two PM domains, 50the first with index 0 and the second with index 1, of a power controller that 51is represented by a node with the label "power". 52 53Optional properties: 54- required-opps: This contains phandle to an OPP node in another device's OPP 55 table. It may contain an array of phandles, where each phandle points to an 56 OPP of a different device. It should not contain multiple phandles to the OPP 57 nodes in the same OPP table. This specifies the minimum required OPP of the 58 device(s), whose OPP's phandle is present in this property, for the 59 functioning of the current device at the current OPP (where this property is 60 present). 61 62Example: 63- OPP table for domain provider that provides two domains. 64 65 domain0_opp_table: opp-table0 { 66 compatible = "operating-points-v2"; 67 68 domain0_opp_0: opp-1000000000 { 69 opp-hz = /bits/ 64 <1000000000>; 70 opp-microvolt = <975000 970000 985000>; 71 }; 72 domain0_opp_1: opp-1100000000 { 73 opp-hz = /bits/ 64 <1100000000>; 74 opp-microvolt = <1000000 980000 1010000>; 75 }; 76 }; 77 78 domain1_opp_table: opp-table1 { 79 compatible = "operating-points-v2"; 80 81 domain1_opp_0: opp-1200000000 { 82 opp-hz = /bits/ 64 <1200000000>; 83 opp-microvolt = <975000 970000 985000>; 84 }; 85 domain1_opp_1: opp-1300000000 { 86 opp-hz = /bits/ 64 <1300000000>; 87 opp-microvolt = <1000000 980000 1010000>; 88 }; 89 }; 90 91 power: power-controller@12340000 { 92 compatible = "foo,power-controller"; 93 reg = <0x12340000 0x1000>; 94 #power-domain-cells = <1>; 95 operating-points-v2 = <&domain0_opp_table>, <&domain1_opp_table>; 96 }; 97 98 leaky-device0@12350000 { 99 compatible = "foo,i-leak-current"; 100 reg = <0x12350000 0x1000>; 101 power-domains = <&power 0>; 102 required-opps = <&domain0_opp_0>; 103 }; 104 105 leaky-device1@12350000 { 106 compatible = "foo,i-leak-current"; 107 reg = <0x12350000 0x1000>; 108 power-domains = <&power 1>; 109 required-opps = <&domain1_opp_1>; 110 }; 111 112[1]. Documentation/devicetree/bindings/power/domain-idle-state.yaml 113