staging: xlnxsync: Add driver for Xilinx Synchronizer

This patch adds the driver for Xilinx Synchronizer. It is used to
monitor the address and help achieve sub frame latency for encoding
and decoding video with the VCU. It is implemented as a misc driver and
comes up as /dev/xlnxsyncX where X is the instance number.

Add support to program the luma/chroma core offset registers at offset
0x400 onwards. These are used when the VCU will be used to encode/decode
a single frame using all the 4/2 cores.

Signed-off-by: Vishal Sagar <vishal.sagar@xilinx.com>
Tested-by: Dylan Yip <dylan.yip@xilinx.com>
Reviewed-by: Hyun Kwon <hyun.kwon@xilinx.com>
State: pending

drivers/staging/Kconfig

@@ -127,4 +127,6 @@ source "drivers/staging/qlge/Kconfig"
 
 source "drivers/staging/fclk/Kconfig"
 
+source "drivers/staging/xlnxsync/Kconfig"
+
 endif # STAGING

drivers/staging/Makefile

@@ -54,3 +54,4 @@ obj-$(CONFIG_USB_WUSB)		+= wusbcore/
 obj-$(CONFIG_EXFAT_FS)		+= exfat/
 obj-$(CONFIG_QLGE)		+= qlge/
 obj-$(CONFIG_XILINX_FCLK)	+= fclk/
+obj-$(CONFIG_XLNX_SYNC)		+= xlnxsync/

drivers/staging/xlnxsync/Kconfig

@@ -0,0 +1,11 @@
+config XLNX_SYNC
+	tristate "Xilinx Synchronizer"
+	depends on ARCH_ZYNQMP
+	help
+	  This driver is developed for Xilinx Synchronizer IP. It is used to
+	  monitor the AXI addresses of the producer and initiate the
+	  consumer to start earlier, thereby reducing the latency to process
+	  the data.
+
+	  To compile this driver as a module, choose M here.
+	  If unsure, choose N

drivers/staging/xlnxsync/MAINTAINERS

@@ -0,0 +1,4 @@
+XILINX SYNCHRONIZER DRIVER
+M:	Vishal Sagar <vishal.sagar@xilinx.com>
+S:	Maintained
+F:	drivers/staging/xlnxsync

drivers/staging/xlnxsync/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_XLNX_SYNC) += xlnxsync.o