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# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
title: Generic PM domains
- Rafael J. Wysocki <>
- Kevin Hilman <>
- Ulf Hansson <>
description: |+
System on chip designs are often divided into multiple PM domains that can be
used for power gating of selected IP blocks for power saving by reduced leakage
This device tree binding can be used to bind PM domain consumer devices with
their PM domains provided by PM domain providers. A PM domain provider can be
represented by any node in the device tree and can provide one or more PM
domains. A consumer node can refer to the provider by a phandle and a set of
phandle arguments (so called PM domain specifiers) of length specified by the
\#power-domain-cells property in the PM domain provider node.
pattern: "^(power-controller|power-domain)(@.*)?$"
$ref: /schemas/types.yaml#/definitions/phandle-array
A phandle of an idle-state that shall be soaked into a generic domain
power state. The idle state definitions are compatible with
domain-idle-state specified in
phandles that are not compatible with domain-idle-state will be ignored.
The domain-idle-state property reflects the idle state of this PM domain
and not the idle states of the devices or sub-domains in the PM domain.
Devices and sub-domains have their own idle-states independent
of the parent domain's idle states. In the absence of this property,
the domain would be considered as capable of being powered-on
or powered-off.
$ref: /schemas/types.yaml#/definitions/phandle-array
Phandles to the OPP tables of power domains provided by a power domain
provider. If the provider provides a single power domain only or all
the power domains provided by the provider have identical OPP tables,
then this shall contain a single phandle. Refer to ../opp/opp.txt
for more information.
Number of cells in a PM domain specifier. Typically 0 for nodes
representing a single PM domain and 1 for nodes providing multiple PM
domains (e.g. power controllers), but can be any value as specified
by device tree binding documentation of particular provider.
A phandle and PM domain specifier as defined by bindings of the power
controller specified by phandle. Some power domains might be powered
from another power domain (or have other hardware specific
dependencies). For representing such dependency a standard PM domain
consumer binding is used. When provided, all domains created
by the given provider should be subdomains of the domain specified
by this binding.
- "#power-domain-cells"
- |
power: power-controller@12340000 {
compatible = "foo,power-controller";
reg = <0x12340000 0x1000>;
#power-domain-cells = <1>;
// The node above defines a power controller that is a PM domain provider and
// expects one cell as its phandle argument.
- |
parent2: power-controller@12340000 {
compatible = "foo,power-controller";
reg = <0x12340000 0x1000>;
#power-domain-cells = <1>;
child2: power-controller@12341000 {
compatible = "foo,power-controller";
reg = <0x12341000 0x1000>;
power-domains = <&parent2 0>;
#power-domain-cells = <1>;
// The nodes above define two power controllers: 'parent' and 'child'.
// Domains created by the 'child' power controller are subdomains of '0' power
// domain provided by the 'parent' power controller.
- |
parent3: power-controller@12340000 {
compatible = "foo,power-controller";
reg = <0x12340000 0x1000>;
#power-domain-cells = <0>;
domain-idle-states = <&DOMAIN_RET>, <&DOMAIN_PWR_DN>;
child3: power-controller@12341000 {
compatible = "foo,power-controller";
reg = <0x12341000 0x1000>;
power-domains = <&parent3>;
#power-domain-cells = <0>;
domain-idle-states = <&DOMAIN_PWR_DN>;
DOMAIN_RET: state@0 {
compatible = "domain-idle-state";
reg = <0x0 0x0>;
entry-latency-us = <1000>;
exit-latency-us = <2000>;
min-residency-us = <10000>;
DOMAIN_PWR_DN: state@1 {
compatible = "domain-idle-state";
reg = <0x1 0x0>;
entry-latency-us = <5000>;
exit-latency-us = <8000>;
min-residency-us = <7000>;