From dbe675433df3966cb4d24e80670a3134ab8757ee Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Wed, 4 Feb 2015 23:44:15 +0900 Subject: [PATCH] dt-bindings: document a note about power domain subdomains This patch adds a note on defining subdomains to generic PM domain binding documentation to let power domain providers use common approach for defining power domain hierarchy. Signed-off-by: Marek Szyprowski Acked-by: Geert Uytterhoeven Reviewed-by: Ulf Hansson Signed-off-by: Kukjin Kim --- .../bindings/power/power_domain.txt | 29 +++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt index 98c16672ab5f..0f8ed3710c66 100644 --- a/Documentation/devicetree/bindings/power/power_domain.txt +++ b/Documentation/devicetree/bindings/power/power_domain.txt @@ -19,6 +19,16 @@ Required properties: providing multiple PM domains (e.g. power controllers), but can be any value as specified by device tree binding documentation of particular provider. +Optional properties: + - power-domains : 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. More details about power domain specifier are + available in the next section. + Example: power: power-controller@12340000 { @@ -30,6 +40,25 @@ Example: The node above defines a power controller that is a PM domain provider and expects one cell as its phandle argument. +Example 2: + + parent: power-controller@12340000 { + compatible = "foo,power-controller"; + reg = <0x12340000 0x1000>; + #power-domain-cells = <1>; + }; + + child: power-controller@12340000 { + compatible = "foo,power-controller"; + reg = <0x12341000 0x1000>; + power-domains = <&parent 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. + ==PM domain consumers== Required properties: -- 2.20.1