1 # SPDX-License-Identifier: GPL-2.0 1 # SPDX-License-Identifier: GPL-2.0
2 %YAML 1.2 2 %YAML 1.2
3 --- 3 ---
4 $id: http://devicetree.org/schemas/power/power 4 $id: http://devicetree.org/schemas/power/power-domain.yaml#
5 $schema: http://devicetree.org/meta-schemas/co 5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6 6
7 title: Generic PM domains 7 title: Generic PM domains
8 8
9 maintainers: 9 maintainers:
10 - Rafael J. Wysocki <rjw@rjwysocki.net> 10 - Rafael J. Wysocki <rjw@rjwysocki.net>
11 - Kevin Hilman <khilman@kernel.org> 11 - Kevin Hilman <khilman@kernel.org>
12 - Ulf Hansson <ulf.hansson@linaro.org> 12 - Ulf Hansson <ulf.hansson@linaro.org>
13 13
14 description: |+ 14 description: |+
15 System on chip designs are often divided int 15 System on chip designs are often divided into multiple PM domains that can be
16 used for power gating of selected IP blocks !! 16 used for power gating of selected IP blocks for power saving by reduced leakage
17 leakage current. Moreover, in some cases the !! 17 current.
18 capable of scaling performance for a group o <<
19 18
20 This device tree binding can be used to bind 19 This device tree binding can be used to bind PM domain consumer devices with
21 their PM domains provided by PM domain provi 20 their PM domains provided by PM domain providers. A PM domain provider can be
22 represented by any node in the device tree a 21 represented by any node in the device tree and can provide one or more PM
23 domains. A consumer node can refer to the pr 22 domains. A consumer node can refer to the provider by a phandle and a set of
24 phandle arguments (so called PM domain speci 23 phandle arguments (so called PM domain specifiers) of length specified by the
25 \#power-domain-cells property in the PM doma 24 \#power-domain-cells property in the PM domain provider node.
26 25
27 properties: 26 properties:
28 $nodename: 27 $nodename:
29 pattern: "^(power-controller|power-domain| !! 28 pattern: "^(power-controller|power-domain)([@-].*)?$"
30 29
31 domain-idle-states: 30 domain-idle-states:
32 $ref: /schemas/types.yaml#/definitions/pha 31 $ref: /schemas/types.yaml#/definitions/phandle-array
33 items: 32 items:
34 maxItems: 1 33 maxItems: 1
35 description: | 34 description: |
36 Phandles of idle states that defines the 35 Phandles of idle states that defines the available states for the
37 power-domain provider. The idle state de 36 power-domain provider. The idle state definitions are compatible with the
38 domain-idle-state bindings, specified in 37 domain-idle-state bindings, specified in ./domain-idle-state.yaml.
39 38
40 Note that, the domain-idle-state propert 39 Note that, the domain-idle-state property reflects the idle states of this
41 PM domain and not the idle states of the 40 PM domain and not the idle states of the devices or sub-domains in the PM
42 domain. Devices and sub-domains have the 41 domain. Devices and sub-domains have their own idle states independent of
43 the parent domain's idle states. In the 42 the parent domain's idle states. In the absence of this property, the
44 domain would be considered as capable of 43 domain would be considered as capable of being powered-on or powered-off.
45 44
46 operating-points-v2: 45 operating-points-v2:
47 description: 46 description:
48 Phandles to the OPP tables of power doma !! 47 Phandles to the OPP tables of power domains provided by a power domain
49 performance, provided by a power domain !! 48 provider. If the provider provides a single power domain only or all
50 a single power domain only or all the po !! 49 the power domains provided by the provider have identical OPP tables,
51 provider have identical OPP tables, then !! 50 then this shall contain a single phandle. Refer to ../opp/opp-v2-base.yaml
52 phandle. Refer to ../opp/opp-v2-base.yam !! 51 for more information.
53 52
54 "#power-domain-cells": 53 "#power-domain-cells":
55 description: 54 description:
56 Number of cells in a PM domain specifier 55 Number of cells in a PM domain specifier. Typically 0 for nodes
57 representing a single PM domain and 1 fo 56 representing a single PM domain and 1 for nodes providing multiple PM
58 domains (e.g. power controllers), but ca 57 domains (e.g. power controllers), but can be any value as specified
59 by device tree binding documentation of 58 by device tree binding documentation of particular provider.
60 59
61 power-domains: 60 power-domains:
62 description: 61 description:
63 A phandle and PM domain specifier as def 62 A phandle and PM domain specifier as defined by bindings of the power
64 controller specified by phandle. Some po 63 controller specified by phandle. Some power domains might be powered
65 from another power domain (or have other 64 from another power domain (or have other hardware specific
66 dependencies). For representing such dep 65 dependencies). For representing such dependency a standard PM domain
67 consumer binding is used. When provided, 66 consumer binding is used. When provided, all domains created
68 by the given provider should be subdomai 67 by the given provider should be subdomains of the domain specified
69 by this binding. 68 by this binding.
70 69
71 required: 70 required:
72 - "#power-domain-cells" 71 - "#power-domain-cells"
73 72
74 additionalProperties: true 73 additionalProperties: true
75 74
76 examples: 75 examples:
77 - | 76 - |
78 power: power-controller@12340000 { 77 power: power-controller@12340000 {
79 compatible = "foo,power-controller"; 78 compatible = "foo,power-controller";
80 reg = <0x12340000 0x1000>; 79 reg = <0x12340000 0x1000>;
81 #power-domain-cells = <1>; 80 #power-domain-cells = <1>;
82 }; 81 };
83 82
84 // The node above defines a power controll 83 // The node above defines a power controller that is a PM domain provider and
85 // expects one cell as its phandle argumen 84 // expects one cell as its phandle argument.
86 85
87 - | 86 - |
88 parent2: power-controller@12340000 { 87 parent2: power-controller@12340000 {
89 compatible = "foo,power-controller"; 88 compatible = "foo,power-controller";
90 reg = <0x12340000 0x1000>; 89 reg = <0x12340000 0x1000>;
91 #power-domain-cells = <1>; 90 #power-domain-cells = <1>;
92 }; 91 };
93 92
94 child2: power-controller@12341000 { 93 child2: power-controller@12341000 {
95 compatible = "foo,power-controller"; 94 compatible = "foo,power-controller";
96 reg = <0x12341000 0x1000>; 95 reg = <0x12341000 0x1000>;
97 power-domains = <&parent2 0>; 96 power-domains = <&parent2 0>;
98 #power-domain-cells = <1>; 97 #power-domain-cells = <1>;
99 }; 98 };
100 99
101 // The nodes above define two power contro 100 // The nodes above define two power controllers: 'parent' and 'child'.
102 // Domains created by the 'child' power co 101 // Domains created by the 'child' power controller are subdomains of '0' power
103 // domain provided by the 'parent' power c 102 // domain provided by the 'parent' power controller.
104 103
105 - | 104 - |
106 parent3: power-controller@12340000 { 105 parent3: power-controller@12340000 {
107 compatible = "foo,power-controller"; 106 compatible = "foo,power-controller";
108 reg = <0x12340000 0x1000>; 107 reg = <0x12340000 0x1000>;
109 #power-domain-cells = <0>; 108 #power-domain-cells = <0>;
110 domain-idle-states = <&DOMAIN_RET>, <& 109 domain-idle-states = <&DOMAIN_RET>, <&DOMAIN_PWR_DN>;
111 }; 110 };
112 111
113 child3: power-controller@12341000 { 112 child3: power-controller@12341000 {
114 compatible = "foo,power-controller"; 113 compatible = "foo,power-controller";
115 reg = <0x12341000 0x1000>; 114 reg = <0x12341000 0x1000>;
116 power-domains = <&parent3>; 115 power-domains = <&parent3>;
117 #power-domain-cells = <0>; 116 #power-domain-cells = <0>;
118 domain-idle-states = <&DOMAIN_PWR_DN>; 117 domain-idle-states = <&DOMAIN_PWR_DN>;
119 }; 118 };
120 119
121 domain-idle-states { 120 domain-idle-states {
122 DOMAIN_RET: domain-retention { 121 DOMAIN_RET: domain-retention {
123 compatible = "domain-idle-state"; 122 compatible = "domain-idle-state";
124 entry-latency-us = <1000>; 123 entry-latency-us = <1000>;
125 exit-latency-us = <2000>; 124 exit-latency-us = <2000>;
126 min-residency-us = <10000>; 125 min-residency-us = <10000>;
127 }; 126 };
128 127
129 DOMAIN_PWR_DN: domain-pwr-dn { 128 DOMAIN_PWR_DN: domain-pwr-dn {
130 compatible = "domain-idle-state"; 129 compatible = "domain-idle-state";
131 entry-latency-us = <5000>; 130 entry-latency-us = <5000>;
132 exit-latency-us = <8000>; 131 exit-latency-us = <8000>;
133 min-residency-us = <7000>; 132 min-residency-us = <7000>;
134 }; 133 };
135 }; 134 };
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