mailbox: Add snapshot of MSM QMP driver

This snapshot is taken as of msm-5.10 'commit <52ccb2676d2b>
("soc: qcom: minidump_log: Add check to avoid NULL pointer dereference")'.

Change-Id: Ia62a11f2fed9194694914d9abb4fe47186958897
Signed-off-by: Chris Lew <clew@codeaurora.org>

drivers/mailbox/Kconfig

@@ -294,4 +294,12 @@ config QCOM_IPCC
 	  acts as an interrupt controller for receiving interrupts from clients.
 	  Say Y here if you want to build this driver.
 
+config MSM_QMP
+	tristate "QTI Mailbox Protocol(QMP)"
+	help
+	  Say yes to add support for the QTI Mailbox Protocol mailbox driver.
+	  QMP is a lightweight communication protocol for sending messages to
+	  a remote processor. This protocol fits into the Generic Mailbox
+	  Framework. QMP uses a mailbox located in shared memory.
+
 endif

drivers/mailbox/Makefile

@@ -62,3 +62,5 @@ obj-$(CONFIG_SPRD_MBOX)		+= sprd-mailbox.o
 obj-$(CONFIG_QCOM_IPCC)		+= qcom-ipcc.o
 
 obj-$(CONFIG_APPLE_MAILBOX)	+= apple-mailbox.o
+
+obj-$(CONFIG_MSM_QMP)   += msm_qmp.o

include/linux/mailbox/qmp.h

@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2017-2021, The Linux Foundation. All rights reserved.
+ */
+
+#ifndef _QMP_H_
+#define _QMP_H_
+
+#include <linux/types.h>
+
+/**
+ * struct qmp_pkt - Packet structure to be used for TX and RX with QMP
+ * @size	size of data
+ * @data	Buffer holding data of this packet
+ */
+struct qmp_pkt {
+	u32 size;
+	void *data;
+};
+
+#endif /* _QMP_H_ */