[PATCH v5 2/8] Documentation: devicetree: psci: define CPU suspend parameter

Lorenzo Pieralisi
2014-06-25T14:10:32Z

OS layers built on top of PSCI to enter low-power states require the
power_state parameter to be passed to the PSCI CPU suspend method.

This parameter is specific to a power state and platform specific,
therefore must be provided by firmware to the OS in order to enable
proper call sequence.

This patch adds a property in the PSCI bindings that describes how
the CPU suspend power_state parameter should be defined in DT in
all device nodes that rely on PSCI CPU suspend method usage.

Reviewed-by: Sebastian Capella <sebcape@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
Documentation/devicetree/bindings/arm/psci.txt | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt
index b4a58f3..fae3eed 100644
--- a/Documentation/devicetree/bindings/arm/psci.txt
+++ b/Documentation/devicetree/bindings/arm/psci.txt
@@ -50,6 +50,14 @@ Main node optional properties:

- migrate : Function ID for MIGRATE operation

+Device tree nodes that require usage of PSCI CPU_SUSPEND function (ie idle
+states bindings[1]) must specify the following properties:
+
+- entry-method-param
+ Usage: Required for idle states bindings [1].
+ Value type: <u32>
+ Definition: power_state parameter to pass to the PSCI
+ suspend call.

Example:

@@ -64,7 +72,6 @@ Case 1: PSCI v0.1 only.
migrate = <0x95c10003>;
};

-
Case 2: PSCI v0.2 only

psci {
@@ -88,3 +95,6 @@ Case 3: PSCI v0.2 and PSCI v0.1.

...
};
+
+[1] Kernel documentation - ARM idle states bindings
+ Documentation/devicetree/bindings/arm/idle-states.txt
--
1.9.1