Re: [Linaro-acpi] [PATCH v2 2/3] Documentation: devicetree: Add new binding for PSCIv0.2

On Thu, Mar 27, 2014 at 10:38 AM, Ashwin Chaugule ashwin.chaugule@linaro.org wrote:

The PSCI v0.2+ spec defines standard values for PSCI function IDs. Add a new binding entry so that pre v0.2 implementations can use DT entries for function IDs and v0.2+ implementations use standard entries as defined by the PSCIv0.2 specification.

Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org

Acked-by: Rob Herring robh@kernel.org

---

Documentation/devicetree/bindings/arm/psci.txt | 35 +++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt index 433afe9..d01a90b 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 +63,26 @@ 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.

•   As described above, for compatibility with existing kernels, the
  

•   hypervisor will likely want to provide IDs, e.g.
  

•   psci {
  

•           compatible = "arm,psci-0.2", "arm,psci";
  

•           method = "hvc";
  

•           cpu_on = < arbitrary value >;
  

•           cpu_off = < arbitrary value >;
  

•           ...
  

•   };
  

-- 1.8.3.2