Texas Instruments TI-SCI Generic Power Domain
---------------------------------------------

Some TI SoCs contain a system controller (like the PMMC, etc...) that are
responsible for control 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. 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.

PM Domains Nodes
================
The PM domains node represents the global PM domain managed by the PMMC,
which in this case is one cell 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-domains"
- #power-domain-cells: Must be 1 so that an offset can be provided in each
		       device node.
- ti,sci: Phandle to the TI SCI device to use for managing the devices


Example:
--------------------
/* From arch/arm/boot/dts/k2g.dtsi */
k2g_pds: k2g_pds {
        compatible = "ti,sci-pm-domains";
        #power-domain-cells = <1>;
        ti,sci = <&pmmc>;
};

PM Domain Consumers
===================
Hardware blocks belonging to a PM domain should contain a "power-domains"
property that is a phandle pointing to the corresponding PM domain node
along with an index representing the device id to be passed for the PMMC
for device control.

See dt-bindings/genpd/k2g.h for the list of valid identifiers for k2g.

Example:
--------------------
/* From arch/arm/boot/dts/k2g.dtsi */
uart0: serial@02530c00 {
	compatible = "ns16550a";
	current-speed = <115200>;
	reg-shift = <2>;
	reg-io-width = <4>;
	reg = <0x02530c00 0x100>;
	interrupts = <GIC_SPI 164 IRQ_TYPE_EDGE_RISING>;
	clock-frequency = <200000000>;
	status = "disabled";
	power-domains = <&k2g_pds K2G_DEV_UART0>;
};