1 # SPDX-License-Identifier: GPL-2.0
4 $id: http://devicetree.org/schemas/power/power-domain.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
7 title: Generic PM domains
10 - Rafael J. Wysocki <rjw@rjwysocki.net>
11 - Kevin Hilman <khilman@kernel.org>
12 - Ulf Hansson <ulf.hansson@linaro.org>
15 System on chip designs are often divided into multiple PM domains that can be
16 used for power gating of selected IP blocks for power saving by reduced leakage
19 This device tree binding can be used to bind PM domain consumer devices with
20 their PM domains provided by PM domain providers. A PM domain provider can be
21 represented by any node in the device tree and can provide one or more PM
22 domains. A consumer node can refer to the provider by a phandle and a set of
23 phandle arguments (so called PM domain specifiers) of length specified by the
24 \#power-domain-cells property in the PM domain provider node.
28 pattern: "^(power-controller|power-domain)([@-].*)?$"
31 $ref: /schemas/types.yaml#/definitions/phandle-array
33 Phandles of idle states that defines the available states for the
34 power-domain provider. The idle state definitions are compatible with the
35 domain-idle-state bindings, specified in ./domain-idle-state.yaml.
37 Note that, the domain-idle-state property reflects the idle states of this
38 PM domain and not the idle states of the devices or sub-domains in the PM
39 domain. Devices and sub-domains have their own idle states independent of
40 the parent domain's idle states. In the absence of this property, the
41 domain would be considered as capable of being powered-on or powered-off.
44 $ref: /schemas/types.yaml#/definitions/phandle-array
46 Phandles to the OPP tables of power domains provided by a power domain
47 provider. If the provider provides a single power domain only or all
48 the power domains provided by the provider have identical OPP tables,
49 then this shall contain a single phandle. Refer to ../opp/opp.txt
52 "#power-domain-cells":
54 Number of cells in a PM domain specifier. Typically 0 for nodes
55 representing a single PM domain and 1 for nodes providing multiple PM
56 domains (e.g. power controllers), but can be any value as specified
57 by device tree binding documentation of particular provider.
61 A phandle and PM domain specifier as defined by bindings of the power
62 controller specified by phandle. Some power domains might be powered
63 from another power domain (or have other hardware specific
64 dependencies). For representing such dependency a standard PM domain
65 consumer binding is used. When provided, all domains created
66 by the given provider should be subdomains of the domain specified
70 - "#power-domain-cells"
74 power: power-controller@12340000 {
75 compatible = "foo,power-controller";
76 reg = <0x12340000 0x1000>;
77 #power-domain-cells = <1>;
80 // The node above defines a power controller that is a PM domain provider and
81 // expects one cell as its phandle argument.
84 parent2: power-controller@12340000 {
85 compatible = "foo,power-controller";
86 reg = <0x12340000 0x1000>;
87 #power-domain-cells = <1>;
90 child2: power-controller@12341000 {
91 compatible = "foo,power-controller";
92 reg = <0x12341000 0x1000>;
93 power-domains = <&parent2 0>;
94 #power-domain-cells = <1>;
97 // The nodes above define two power controllers: 'parent' and 'child'.
98 // Domains created by the 'child' power controller are subdomains of '0' power
99 // domain provided by the 'parent' power controller.
102 parent3: power-controller@12340000 {
103 compatible = "foo,power-controller";
104 reg = <0x12340000 0x1000>;
105 #power-domain-cells = <0>;
106 domain-idle-states = <&DOMAIN_RET>, <&DOMAIN_PWR_DN>;
109 child3: power-controller@12341000 {
110 compatible = "foo,power-controller";
111 reg = <0x12341000 0x1000>;
112 power-domains = <&parent3>;
113 #power-domain-cells = <0>;
114 domain-idle-states = <&DOMAIN_PWR_DN>;
117 DOMAIN_RET: state@0 {
118 compatible = "domain-idle-state";
120 entry-latency-us = <1000>;
121 exit-latency-us = <2000>;
122 min-residency-us = <10000>;
125 DOMAIN_PWR_DN: state@1 {
126 compatible = "domain-idle-state";
128 entry-latency-us = <5000>;
129 exit-latency-us = <8000>;
130 min-residency-us = <7000>;