diff options
Diffstat (limited to 'Documentation/devicetree/bindings/arm')
| -rw-r--r-- | Documentation/devicetree/bindings/arm/psci.txt | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt index 433afe9cb590..b4a58f39223c 100644 --- a/Documentation/devicetree/bindings/arm/psci.txt +++ b/Documentation/devicetree/bindings/arm/psci.txt @@ -21,7 +21,15 @@ to #0. Main node required properties: - - compatible : Must be "arm,psci" + - compatible : should contain at least one of: + + * "arm,psci" : for implementations complying to PSCI versions prior to + 0.2. For these cases function IDs must be provided. + + * "arm,psci-0.2" : for implementations complying to PSCI 0.2. Function + IDs are not required and should be ignored by an OS with PSCI 0.2 + support, but are permitted to be present for compatibility with + existing software when "arm,psci" is later in the compatible list. - method : The method of calling the PSCI firmware. Permitted values are: @@ -45,6 +53,8 @@ Main node optional properties: Example: +Case 1: PSCI v0.1 only. + psci { compatible = "arm,psci"; method = "smc"; @@ -53,3 +63,28 @@ Example: cpu_on = <0x95c10002>; migrate = <0x95c10003>; }; + + +Case 2: PSCI v0.2 only + + psci { + compatible = "arm,psci-0.2"; + method = "smc"; + }; + +Case 3: PSCI v0.2 and PSCI v0.1. + + A DTB may provide IDs for use by kernels without PSCI 0.2 support, + enabling firmware and hypervisors to support existing and new kernels. + These IDs will be ignored by kernels with PSCI 0.2 support, which will + use the standard PSCI 0.2 IDs exclusively. + + psci { + compatible = "arm,psci-0.2", "arm,psci"; + method = "hvc"; + + cpu_on = < arbitrary value >; + cpu_off = < arbitrary value >; + + ... + }; |