xref: /linux/Documentation/devicetree/bindings/power/power-domain.yaml (revision 8bb5e7f4dcd9b9ef22a3ea25c9066a8a968f12dd) 
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    items:
33      maxItems: 1
34    description: |
35      Phandles of idle states that defines the available states for the
36      power-domain provider. The idle state definitions are compatible with the
37      domain-idle-state bindings, specified in ./domain-idle-state.yaml.
38
39      Note that, the domain-idle-state property reflects the idle states of this
40      PM domain and not the idle states of the devices or sub-domains in the PM
41      domain. Devices and sub-domains have their own idle states independent of
42      the parent domain's idle states. In the absence of this property, the
43      domain would be considered as capable of being powered-on or powered-off.
44
45  operating-points-v2:
46    $ref: /schemas/types.yaml#/definitions/phandle-array
47    items:
48      maxItems: 1
49    description:
50      Phandles to the OPP tables of power domains provided by a power domain
51      provider. If the provider provides a single power domain only or all
52      the power domains provided by the provider have identical OPP tables,
53      then this shall contain a single phandle. Refer to ../opp/opp-v2-base.yaml
54      for more information.
55
56  "#power-domain-cells":
57    description:
58      Number of cells in a PM domain specifier. Typically 0 for nodes
59      representing a single PM domain and 1 for nodes providing multiple PM
60      domains (e.g. power controllers), but can be any value as specified
61      by device tree binding documentation of particular provider.
62
63  power-domains:
64    description:
65      A phandle and PM domain specifier as defined by bindings of the power
66      controller specified by phandle. Some power domains might be powered
67      from another power domain (or have other hardware specific
68      dependencies). For representing such dependency a standard PM domain
69      consumer binding is used. When provided, all domains created
70      by the given provider should be subdomains of the domain specified
71      by this binding.
72
73required:
74  - "#power-domain-cells"
75
76additionalProperties: true
77
78examples:
79  - |
80    power: power-controller@12340000 {
81        compatible = "foo,power-controller";
82        reg = <0x12340000 0x1000>;
83        #power-domain-cells = <1>;
84    };
85
86    // The node above defines a power controller that is a PM domain provider and
87    // expects one cell as its phandle argument.
88
89  - |
90    parent2: power-controller@12340000 {
91        compatible = "foo,power-controller";
92        reg = <0x12340000 0x1000>;
93        #power-domain-cells = <1>;
94    };
95
96    child2: power-controller@12341000 {
97        compatible = "foo,power-controller";
98        reg = <0x12341000 0x1000>;
99        power-domains = <&parent2 0>;
100        #power-domain-cells = <1>;
101    };
102
103    // The nodes above define two power controllers: 'parent' and 'child'.
104    // Domains created by the 'child' power controller are subdomains of '0' power
105    // domain provided by the 'parent' power controller.
106
107  - |
108    parent3: power-controller@12340000 {
109        compatible = "foo,power-controller";
110        reg = <0x12340000 0x1000>;
111        #power-domain-cells = <0>;
112        domain-idle-states = <&DOMAIN_RET>, <&DOMAIN_PWR_DN>;
113    };
114
115    child3: power-controller@12341000 {
116        compatible = "foo,power-controller";
117        reg = <0x12341000 0x1000>;
118        power-domains = <&parent3>;
119        #power-domain-cells = <0>;
120        domain-idle-states = <&DOMAIN_PWR_DN>;
121    };
122
123    domain-idle-states {
124        DOMAIN_RET: domain-retention {
125            compatible = "domain-idle-state";
126            entry-latency-us = <1000>;
127            exit-latency-us = <2000>;
128            min-residency-us = <10000>;
129        };
130
131        DOMAIN_PWR_DN: domain-pwr-dn {
132            compatible = "domain-idle-state";
133            entry-latency-us = <5000>;
134            exit-latency-us = <8000>;
135            min-residency-us = <7000>;
136        };
137    };
138