1# SPDX-License-Identifier: GPL-2.0
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/power/power-domain.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Generic PM domains
8
9maintainers:
10  - Rafael J. Wysocki <rjw@rjwysocki.net>
11  - Kevin Hilman <khilman@kernel.org>
12  - Ulf Hansson <ulf.hansson@linaro.org>
13
14description: |+
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
17  current.
18
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.
25
26properties:
27  $nodename:
28    pattern: "^(power-controller|power-domain)(@.*)?$"
29
30  domain-idle-states:
31    $ref: /schemas/types.yaml#/definitions/phandle-array
32    description:
33      A phandle of an idle-state that shall be soaked into a generic domain
34      power state. The idle state definitions are compatible with
35      domain-idle-state specified in
36      Documentation/devicetree/bindings/power/domain-idle-state.txt
37      phandles that are not compatible with domain-idle-state will be ignored.
38      The domain-idle-state property reflects the idle state of this PM domain
39      and not the idle states of the devices or sub-domains in the PM domain.
40      Devices and sub-domains have their own idle-states independent
41      of the parent domain's idle states. In the absence of this property,
42      the domain would be considered as capable of being powered-on
43      or powered-off.
44
45  operating-points-v2:
46    $ref: /schemas/types.yaml#/definitions/phandle-array
47    description:
48      Phandles to the OPP tables of power domains provided by a power domain
49      provider. If the provider provides a single power domain only or all
50      the power domains provided by the provider have identical OPP tables,
51      then this shall contain a single phandle. Refer to ../opp/opp.txt
52      for more information.
53
54  "#power-domain-cells":
55    description:
56      Number of cells in a PM domain specifier. Typically 0 for nodes
57      representing a single PM domain and 1 for nodes providing multiple PM
58      domains (e.g. power controllers), but can be any value as specified
59      by device tree binding documentation of particular provider.
60
61  power-domains:
62    description:
63       A phandle and PM domain specifier as defined by bindings of the power
64       controller specified by phandle. Some power domains might be powered
65       from another power domain (or have other hardware specific
66       dependencies). For representing such dependency a standard PM domain
67       consumer binding is used. When provided, all domains created
68       by the given provider should be subdomains of the domain specified
69       by this binding.
70
71required:
72  - "#power-domain-cells"
73
74examples:
75  - |
76    power: power-controller@12340000 {
77        compatible = "foo,power-controller";
78        reg = <0x12340000 0x1000>;
79        #power-domain-cells = <1>;
80    };
81
82    // The node above defines a power controller that is a PM domain provider and
83    // expects one cell as its phandle argument.
84
85  - |
86    parent2: power-controller@12340000 {
87        compatible = "foo,power-controller";
88        reg = <0x12340000 0x1000>;
89        #power-domain-cells = <1>;
90    };
91
92    child2: power-controller@12341000 {
93        compatible = "foo,power-controller";
94        reg = <0x12341000 0x1000>;
95        power-domains = <&parent2 0>;
96        #power-domain-cells = <1>;
97    };
98
99    // The nodes above define two power controllers: 'parent' and 'child'.
100    // Domains created by the 'child' power controller are subdomains of '0' power
101    // domain provided by the 'parent' power controller.
102
103  - |
104    parent3: power-controller@12340000 {
105        compatible = "foo,power-controller";
106        reg = <0x12340000 0x1000>;
107        #power-domain-cells = <0>;
108        domain-idle-states = <&DOMAIN_RET>, <&DOMAIN_PWR_DN>;
109    };
110
111    child3: power-controller@12341000 {
112        compatible = "foo,power-controller";
113        reg = <0x12341000 0x1000>;
114        power-domains = <&parent3>;
115        #power-domain-cells = <0>;
116        domain-idle-states = <&DOMAIN_PWR_DN>;
117    };
118
119    DOMAIN_RET: state@0 {
120        compatible = "domain-idle-state";
121        reg = <0x0 0x0>;
122        entry-latency-us = <1000>;
123        exit-latency-us = <2000>;
124        min-residency-us = <10000>;
125    };
126
127    DOMAIN_PWR_DN: state@1 {
128        compatible = "domain-idle-state";
129        reg = <0x1 0x0>;
130        entry-latency-us = <5000>;
131        exit-latency-us = <8000>;
132        min-residency-us = <7000>;
133    };
134