Commit | Line | Data |
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aa42240a TF |
1 | * Generic PM domains |
2 | ||
3 | System on chip designs are often divided into multiple PM domains that can be | |
4 | used for power gating of selected IP blocks for power saving by reduced leakage | |
5 | current. | |
6 | ||
7 | This device tree binding can be used to bind PM domain consumer devices with | |
8 | their PM domains provided by PM domain providers. A PM domain provider can be | |
9 | represented by any node in the device tree and can provide one or more PM | |
10 | domains. A consumer node can refer to the provider by a phandle and a set of | |
11 | phandle arguments (so called PM domain specifiers) of length specified by the | |
12 | #power-domain-cells property in the PM domain provider node. | |
13 | ||
14 | ==PM domain providers== | |
15 | ||
16 | Required properties: | |
17 | - #power-domain-cells : Number of cells in a PM domain specifier; | |
18 | Typically 0 for nodes representing a single PM domain and 1 for nodes | |
19 | providing multiple PM domains (e.g. power controllers), but can be any value | |
20 | as specified by device tree binding documentation of particular provider. | |
21 | ||
22 | Example: | |
23 | ||
24 | power: power-controller@12340000 { | |
25 | compatible = "foo,power-controller"; | |
26 | reg = <0x12340000 0x1000>; | |
27 | #power-domain-cells = <1>; | |
28 | }; | |
29 | ||
30 | The node above defines a power controller that is a PM domain provider and | |
31 | expects one cell as its phandle argument. | |
32 | ||
33 | ==PM domain consumers== | |
34 | ||
35 | Required properties: | |
36 | - power-domains : A phandle and PM domain specifier as defined by bindings of | |
37 | the power controller specified by phandle. | |
38 | ||
39 | Example: | |
40 | ||
41 | leaky-device@12350000 { | |
42 | compatible = "foo,i-leak-current"; | |
43 | reg = <0x12350000 0x1000>; | |
44 | power-domains = <&power 0>; | |
45 | }; | |
46 | ||
47 | The node above defines a typical PM domain consumer device, which is located | |
48 | inside a PM domain with index 0 of a power controller represented by a node | |
49 | with the label "power". |