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 <nm@ti.com>
Signed-off-by: Dave Gerlach <redacted>
---
 .../devicetree/bindings/soc/ti/sci-pm-domain.txt   | 54 +++++++++++++
 MAINTAINERS                                        |  2 +
 include/dt-bindings/genpd/k2g.h                    | 90 ++++++++++++++++++++++
 3 files changed, 146 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..32f38a349656
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt

@@ -0,0 +1,54 @@
+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.
+
+Required Properties:
+--------------------
+- compatible: should be "ti,sci-pm-domain"
+- #power-domain-cells: Must be 0.
+- ti,sci: Phandle to the TI SCI device to use for managing the devices.
+
+Example:
+--------------------
+k2g_pds: k2g_pds {
+        compatible = "ti,sci-pm-domain";
+        #power-domain-cells = <0>;
+        ti,sci = <&pmmc>;
+};