Add a generic power domain implementation, TI SCI PM Domains, that
will hook into the genpd framework and allow the TI SCI protocol to
control device power states.

Also, provide macros representing each device index as understood
by TI SCI to be used in the device node power-domain references.
These are identifiers for the K2G devices managed by the PMMC.

Signed-off-by: Nishanth Menon <redacted>
Signed-off-by: Dave Gerlach <redacted>
---
v2->v3:
	Update k2g_pds node docs to show it should be a child of pmmc node.
	In early versions a phandle was used to point to pmmc and docs still
	incorrectly showed this.

 .../devicetree/bindings/soc/ti/sci-pm-domain.txt   | 59 ++++++++++++++
 MAINTAINERS                                        |  2 +
 include/dt-bindings/genpd/k2g.h                    | 90 ++++++++++++++++++++++
 3 files changed, 151 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
 create mode 100644 include/dt-bindings/genpd/k2g.h

diff --git a/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt b/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
new file mode 100644
index 000000000000..4c9064e512cb
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt

@@ -0,0 +1,59 @@
+Texas Instruments TI-SCI Generic Power Domain
+---------------------------------------------
+
+Some TI SoCs contain a system controller (like the PMMC, etc...) that is
+responsible for controlling the state of the IPs that are present.
+Communication between the host processor running an OS and the system
+controller happens through a protocol known as TI-SCI [1]. This pm domain
+implementation plugs into the generic pm domain framework and makes use of
+the TI SCI protocol power on and off each device when needed.
+
+[1] Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
+
+PM Domain Node
+==============
+The PM domain node represents the global PM domain managed by the PMMC,
+which in this case is the single implementation as documented by the generic
+PM domain bindings in Documentation/devicetree/bindings/power/power_domain.txt.
+Because this relies on the TI SCI protocol to communicate with the PMMC it
+must be a child of the pmmc node.
+
+Required Properties:
+--------------------
+- compatible: should be "ti,sci-pm-domain"
+- #power-domain-cells: Must be 0.
+
+Example (K2G):
+-------------
+	pmmc: pmmc {
+		compatible = "ti,k2g-sci";
+		...
+
+		k2g_pds: k2g_pds {
+			compatible = "ti,sci-pm-domain";
+			#power-domain-cells = <0>;
+		};
+	};
+
+PM Domain Consumers
+===================
+Hardware blocks that require SCI control over their state must provide
+a reference to the sci-pm-domain they are part of and a unique device
+specific ID that identifies the device.
+
+Required Properties:
+--------------------
+- power-domains: phandle pointing to the corresponding PM domain node.
+- ti,sci-id: index representing the device id to be passed oevr SCI to
+	     be used for device control.