Qualcomm Technologies, Inc. QTI Mailbox Protocol

QMP Driver
===================

Required properties:
- compatible : should be "qcom,qmp-mbox".
- label : the name of the remote proc this link connects to.
- reg : The location and size of shared memory.
	The irq register base address for triggering interrupts.
- reg-names : "msgram" - string to identify the shared memory region.
	"irq-reg-base" - string to identify the irq register region.
- qcom,irq-mask : the bitmask to trigger an interrupt.
- mboxes: - Handle to outgoing interrupt if not using irq-reg-base
- interrupt : the receiving interrupt line.
- mbox-desc-offset : offset of mailbox descriptor from start of the msgram.
- priority : the priority of this mailbox compared to other mailboxes.
- #mbox-cells: Common mailbox binding property to identify the number of cells
		required for the mailbox specifier, should be 1.

Optional properties:
- qcom,early-boot : bool to indicate that this remote proc will boot before QMP.
- mbox-offset : offset of the mcore mailbox from the offset of msgram. If this
			property is not used, qmp will use the configuration
			provided by the ucore.
- mbox-size : size of the mcore mailbox. If this property is not used, qmp will
			use the configuration provided by the ucore.

Example:
	qmp_aop: qcom,qmp-aop {
		compatible = "qcom,qmp-mbox";
		label = "aop";
		qcom,early-boot;
		reg = <0xc300000 0x100000>,
			<0x1799000C 0x4>;
		reg-names = "msgram", "irq-reg-base";
		qcom,irq-mask = <0x1>;
		interrupt = <0 389 1>;
		mbox-desc-offset = <0x100>;
		priority = <1>;
		mbox-offset = <0x500>;
		mbox-size = <0x400>;
		#mbox-cells = <1>;
	};

Mailbox Client
==============
"mboxes" and the optional "mbox-names" (please see
Documentation/devicetree/bindings/mailbox/mailbox.txt for details). Each value
of the mboxes property should contain a phandle to the mailbox controller
device node and second argument is the channel index. It must be 0 (qmp
supports only one channel).The equivalent "mbox-names" property value can be
used to give a name to the communication channel to be used by the client user.

Example:
	qmp-client {
		compatible = "qcom,qmp-client";
		mbox-names = "aop";
		mboxes = <&qmp_aop 0>,
	};
