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author | Olof Johansson <olof@lixom.net> | 2013-02-11 12:05:45 -0500 |
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committer | Olof Johansson <olof@lixom.net> | 2013-02-11 12:05:45 -0500 |
commit | 3ad06d1a7dfd99a2e8f3a41e0fa5118551186d3c (patch) | |
tree | 0cc362f48415c6de501c2474572be94a37014657 /Documentation/devicetree/bindings/arm | |
parent | 4f5c1c04f8623387ce4af942b2bf547d3bba40ae (diff) | |
parent | 2bdd424f26be1c98b6e3d9acfffb5559c131c888 (diff) |
Merge branch 'depends/rmk-psci' into next/virt
Diffstat (limited to 'Documentation/devicetree/bindings/arm')
-rw-r--r-- | Documentation/devicetree/bindings/arm/psci.txt | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt new file mode 100644 index 000000000000..433afe9cb590 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/psci.txt | |||
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1 | * Power State Coordination Interface (PSCI) | ||
2 | |||
3 | Firmware implementing the PSCI functions described in ARM document number | ||
4 | ARM DEN 0022A ("Power State Coordination Interface System Software on ARM | ||
5 | processors") can be used by Linux to initiate various CPU-centric power | ||
6 | operations. | ||
7 | |||
8 | Issue A of the specification describes functions for CPU suspend, hotplug | ||
9 | and migration of secure software. | ||
10 | |||
11 | Functions are invoked by trapping to the privilege level of the PSCI | ||
12 | firmware (specified as part of the binding below) and passing arguments | ||
13 | in a manner similar to that specified by AAPCS: | ||
14 | |||
15 | r0 => 32-bit Function ID / return value | ||
16 | {r1 - r3} => Parameters | ||
17 | |||
18 | Note that the immediate field of the trapping instruction must be set | ||
19 | to #0. | ||
20 | |||
21 | |||
22 | Main node required properties: | ||
23 | |||
24 | - compatible : Must be "arm,psci" | ||
25 | |||
26 | - method : The method of calling the PSCI firmware. Permitted | ||
27 | values are: | ||
28 | |||
29 | "smc" : SMC #0, with the register assignments specified | ||
30 | in this binding. | ||
31 | |||
32 | "hvc" : HVC #0, with the register assignments specified | ||
33 | in this binding. | ||
34 | |||
35 | Main node optional properties: | ||
36 | |||
37 | - cpu_suspend : Function ID for CPU_SUSPEND operation | ||
38 | |||
39 | - cpu_off : Function ID for CPU_OFF operation | ||
40 | |||
41 | - cpu_on : Function ID for CPU_ON operation | ||
42 | |||
43 | - migrate : Function ID for MIGRATE operation | ||
44 | |||
45 | |||
46 | Example: | ||
47 | |||
48 | psci { | ||
49 | compatible = "arm,psci"; | ||
50 | method = "smc"; | ||
51 | cpu_suspend = <0x95c10000>; | ||
52 | cpu_off = <0x95c10001>; | ||
53 | cpu_on = <0x95c10002>; | ||
54 | migrate = <0x95c10003>; | ||
55 | }; | ||