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      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.
36
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.
42
43  operating-points-v2:
44    $ref: /schemas/types.yaml#/definitions/phandle-array
45    description:
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-v2-base.yaml
50      for more information.
51
52  "#power-domain-cells":
53    description:
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.
58
59  power-domains:
60    description:
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
67      by this binding.
68
69required:
70  - "#power-domain-cells"
71
72additionalProperties: true
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-idle-states {
120        DOMAIN_RET: domain-retention {
121            compatible = "domain-idle-state";
122            entry-latency-us = <1000>;
123            exit-latency-us = <2000>;
124            min-residency-us = <10000>;
125        };
126
127        DOMAIN_PWR_DN: domain-pwr-dn {
128            compatible = "domain-idle-state";
129            entry-latency-us = <5000>;
130            exit-latency-us = <8000>;
131            min-residency-us = <7000>;
132        };
133    };
134