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 >;
+
+                ...
+        };