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

include/linux/soc/ti/ti-msgmgr.h

+/*
+ * Texas Instruments' Message Manager
+ *
+ * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
+ *	Nishanth Menon
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef TI_MSGMGR_H
+#define TI_MSGMGR_H
+
+/**
+ * struct ti_msgmgr_message - Message Manager structure
+ * @len: Length of data in the Buffer
+ * @buf: Buffer pointer
+ *
+ * This is the structure for data used in mbox_send_message
+ * the length of data buffer used depends on the SoC integration
+ * parameters - each message may be 64, 128 bytes long depending
+ * on SoC. Client is supposed to be aware of this.
+ */
+struct ti_msgmgr_message {
+	size_t len;
+	u8 *buf;
+};
+
+#endif /* TI_MSGMGR_H */