PM / Domains: Fix compatible for domain idle state

Re-using idle state definition provided by arm,idle-state for domain
idle states creates a lot of confusion and limits further evolution of
the domain idle definition. To keep things clear and simple, define a
idle states for domain using a new compatible "domain-idle-state".

Fix existing PM domains code to look for the newly defined compatible.

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Documentation/devicetree/bindings/power/domain-idle-state.txt

@@ -0,0 +1,33 @@
+PM Domain Idle State Node:
+
+A domain idle state node represents the state parameters that will be used to
+select the state when there are no active components in the domain.
+
+The state node has the following parameters -
+
+- compatible:
+	Usage: Required
+	Value type: <string>
+	Definition: Must be "domain-idle-state".
+
+- entry-latency-us
+	Usage: Required
+	Value type: <prop-encoded-array>
+	Definition: u32 value representing worst case latency in
+		    microseconds required to enter the idle state.
+		    The exit-latency-us duration may be guaranteed
+		    only after entry-latency-us has passed.
+
+- exit-latency-us
+	Usage: Required
+	Value type: <prop-encoded-array>
+	Definition: u32 value representing worst case latency
+		    in microseconds required to exit the idle state.
+
+- min-residency-us
+	Usage: Required
+	Value type: <prop-encoded-array>
+	Definition: u32 value representing minimum residency duration
+		    in microseconds after which the idle state will yield
+		    power benefits after overcoming the overhead in entering
+i		    the idle state.

Documentation/devicetree/bindings/power/power_domain.txt

@@ -31,7 +31,7 @@ Optional properties:
 
 - domain-idle-states : A phandle of an idle-state that shall be soaked into a
                 generic domain power state. The idle state definitions are
-                compatible with arm,idle-state specified in [1].
+                compatible with domain-idle-state specified in [1].
   The domain-idle-state property reflects the idle state of this PM domain and
   not the idle states of the devices or sub-domains in the PM domain. Devices
   and sub-domains have their own idle-states independent of the parent
@@ -85,7 +85,7 @@ Example 3:
 	};
 
 	DOMAIN_RET: state@0 {
-		compatible = "arm,idle-state";
+		compatible = "domain-idle-state";
 		reg = <0x0>;
 		entry-latency-us = <1000>;
 		exit-latency-us = <2000>;
@@ -93,7 +93,7 @@ Example 3:
 	};
 
 	DOMAIN_PWR_DN: state@1 {
-		compatible = "arm,idle-state";
+		compatible = "domain-idle-state";
 		reg = <0x1>;
 		entry-latency-us = <5000>;
 		exit-latency-us = <8000>;
@@ -118,4 +118,4 @@ The node above defines a typical PM domain consumer device, which is located
 inside a PM domain with index 0 of a power controller represented by a node
 with the label "power".
 
-[1]. Documentation/devicetree/bindings/arm/idle-states.txt
+[1]. Documentation/devicetree/bindings/power/domain-idle-state.txt

drivers/base/power/domain.c

@@ -2049,7 +2049,7 @@ out:
 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
 
 static const struct of_device_id idle_state_match[] = {
-	{ .compatible = "arm,idle-state", },
+	{ .compatible = "domain-idle-state", },
 	{ }
 };