Texas Instruments' Message Manager Driver
========================================

The Texas Instruments' Message Manager is a mailbox controller that has
configurable queues selectable at SoC(System on Chip) integration. The Message
manager is broken up into queues in different address regions that are called
"proxies" - each instance is unidirectional and is instantiated at SoC
integration level to indicate receive or transmit path.

Message Manager Device Node:
===========================
Required properties:
--------------------
- compatible:		Shall be: "ti,k2g-message-manager"
- reg-names 		queue_proxy_region - Map the queue proxy region.
			queue_state_debug_region - Map the queue state debug
			region.
- reg:			Contains the register map per reg-names.
- #mbox-cells		Shall be 2. Contains the queue ID and proxy ID in that
		        order referring to the transfer path.
- interrupt-names:	Contains interrupt names matching the rx transfer path
			for a given SoC. Receive interrupts shall be of the
			format: "rx_<QID>_<PID>".
			For ti,k2g-message-manager, this shall contain:
				"rx_005_002", "rx_057_002"
- interrupts:		Contains the interrupt information corresponding to
			interrupt-names property.

Example(K2G):
------------

	msgmgr: msgmgr@2a00000 {
		compatible = "ti,k2g-message-manager";
		#mbox-cells = <2>;
		reg-names = "queue_proxy_region", "queue_state_debug_region";
		reg = <0x02a00000 0x400000>, <0x028c3400 0x400>;
		interrupt-names = "rx_005", "rx_057";
		interrupts = <GIC_SPI 324 IRQ_TYPE_LEVEL_HIGH>,
			     <GIC_SPI 327 IRQ_TYPE_LEVEL_HIGH>;
	};

	pmmc: pmmc {
		[...]
		mbox-names = "rx", "tx";
		# RX queue ID is 5, proxy ID is 2
		# TX queue ID is 0, proxy ID is 0
		mboxes= <&msgmgr 5 2>,
			<&msgmgr 0 0>;
		[...]
	};