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

From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org,
	devicetree@vger.kernel.org
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Charles Garcia Tobin <Charles.Garcia-Tobin@arm.com>,
	Nicolas Pitre <nico@linaro.org>, Rob Herring <robh+dt@kernel.org>,
	Grant Likely <grant.likely@linaro.org>,
	Peter De Schrijver <pdeschrijver@nvidia.com>,
	Santosh Shilimkar <santosh.shilimkar@ti.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Amit Kucheria <amit.kucheria@linaro.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Antti Miettinen <ananaza@iki.fi>,
	Stephen Boyd <sboyd@codeaurora.org>,
	Kevin Hilman <khilman@linaro.org>,
	Sebastian Capella <sebcape@gmail.com>,
	Tomasz Figa <t.figa@samsung.com>, Mark Brown <broonie@kernel.org>,
	Paul Walmsley <paul@pwsan.com>,
	Chander Kashyap <chander.kashyap@linaro.org>
Subject: [PATCH v5 2/8] Documentation: devicetree: psci: define CPU suspend parameter
Date: Wed, 25 Jun 2014 15:10:15 +0100	[thread overview]
Message-ID: <1403705421-17597-3-git-send-email-lorenzo.pieralisi@arm.com> (raw)
In-Reply-To: <1403705421-17597-1-git-send-email-lorenzo.pieralisi@arm.com>

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


