mailbox: Introduce TI message manager driver

Support for TI Message Manager Module. This hardware block manages a
bunch of hardware queues meant for communication between processor
entities.

Clients sitting on top of this would manage the required protocol
for communicating with the counterpart entities.

For more details on TI Message Manager hardware block, see documentation
that will is available here: http://www.ti.com/lit/ug/spruhy8/spruhy8.pdf
Chapter 8.1(Message Manager)

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

drivers/mailbox/Kconfig

@@ -87,6 +87,17 @@ config STI_MBOX
 	  Mailbox implementation for STMicroelectonics family chips with
 	  hardware for interprocessor communication.
 
+config TI_MESSAGE_MANAGER
+	tristate "Texas Instruments Message Manager Driver"
+	depends on ARCH_KEYSTONE
+	help
+	  An implementation of Message Manager slave driver for Keystone
+	  architecture SoCs from Texas Instruments. Message Manager is a
+	  communication entity found on few of Texas Instrument's keystone
+	  architecture SoCs. These may be used for communication between
+	  multiple processors within the SoC. Select this driver if your
+	  platform has support for the hardware block.
+
 config HI6220_MBOX
 	tristate "Hi6220 Mailbox"
 	depends on ARCH_HISI

drivers/mailbox/Makefile

@@ -20,6 +20,8 @@ obj-$(CONFIG_BCM2835_MBOX)	+= bcm2835-mailbox.o
 
 obj-$(CONFIG_STI_MBOX)		+= mailbox-sti.o
 
+obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o
+
 obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
 
 obj-$(CONFIG_HI6220_MBOX)	+= hi6220-mailbox.o