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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/devicetree/bindings/power/power_domain.txt
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
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+* Generic PM domains
+
+System on chip designs are often divided into multiple PM domains that can be
+used for power gating of selected IP blocks for power saving by reduced leakage
+current.
+
+This device tree binding can be used to bind PM domain consumer devices with
+their PM domains provided by PM domain providers. A PM domain provider can be
+represented by any node in the device tree and can provide one or more PM
+domains. A consumer node can refer to the provider by a phandle and a set of
+phandle arguments (so called PM domain specifiers) of length specified by the
+#power-domain-cells property in the PM domain provider node.
+
+==PM domain providers==
+
+Required properties:
+ - #power-domain-cells : Number of cells in a PM domain specifier;
+ Typically 0 for nodes representing a single PM domain and 1 for nodes
+ providing multiple PM domains (e.g. power controllers), but can be any value
+ as specified by device tree binding documentation of particular provider.
+
+Optional properties:
+ - power-domains : A phandle and PM domain specifier as defined by bindings of
+ the power controller specified by phandle.
+ Some power domains might be powered from another power domain (or have
+ other hardware specific dependencies). For representing such dependency
+ a standard PM domain consumer binding is used. When provided, all domains
+ created by the given provider should be subdomains of the domain
+ specified by this binding. More details about power domain specifier are
+ available in the next section.
+
+Example:
+
+ power: power-controller@12340000 {
+ compatible = "foo,power-controller";
+ reg = <0x12340000 0x1000>;
+ #power-domain-cells = <1>;
+ };
+
+The node above defines a power controller that is a PM domain provider and
+expects one cell as its phandle argument.
+
+Example 2:
+
+ parent: power-controller@12340000 {
+ compatible = "foo,power-controller";
+ reg = <0x12340000 0x1000>;
+ #power-domain-cells = <1>;
+ };
+
+ child: power-controller@12340000 {
+ compatible = "foo,power-controller";
+ reg = <0x12341000 0x1000>;
+ power-domains = <&parent 0>;
+ #power-domain-cells = <1>;
+ };
+
+The nodes above define two power controllers: 'parent' and 'child'.
+Domains created by the 'child' power controller are subdomains of '0' power
+domain provided by the 'parent' power controller.
+
+==PM domain consumers==
+
+Required properties:
+ - power-domains : A phandle and PM domain specifier as defined by bindings of
+ the power controller specified by phandle.
+
+Example:
+
+ leaky-device@12350000 {
+ compatible = "foo,i-leak-current";
+ reg = <0x12350000 0x1000>;
+ power-domains = <&power 0>;
+ };
+
+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".