serial/arc-uart: Add new driver

Driver for non-standard on-chip UART, instantiated in the ARC (Synopsys)
FPGA Boards such as ARCAngel4/ML50x

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/Kconfig

@@ -1423,4 +1423,27 @@ config SERIAL_EFM32_UART_CONSOLE
 	depends on SERIAL_EFM32_UART=y
 	select SERIAL_CORE_CONSOLE
 
+config SERIAL_ARC
+	tristate "ARC UART driver support"
+	select SERIAL_CORE
+	help
+	  Driver for on-chip UART for ARC(Synopsys) for the legacy
+	  FPGA Boards (ML50x/ARCAngel4)
+
+config SERIAL_ARC_CONSOLE
+	bool "Console on ARC UART"
+	depends on SERIAL_ARC=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Enable system Console on ARC UART
+
+config SERIAL_ARC_NR_PORTS
+	int "Number of ARC UART ports"
+	depends on SERIAL_ARC
+	range 1 3
+	default "1"
+	help
+	  Set this to the number of serial ports you want the driver
+	  to support.
+
 endmenu

drivers/tty/serial/Makefile

@@ -82,3 +82,4 @@ obj-$(CONFIG_SERIAL_XILINX_PS_UART) += xilinx_uartps.o
 obj-$(CONFIG_SERIAL_SIRFSOC) += sirfsoc_uart.o
 obj-$(CONFIG_SERIAL_AR933X)   += ar933x_uart.o
 obj-$(CONFIG_SERIAL_EFM32_UART) += efm32-uart.o
+obj-$(CONFIG_SERIAL_ARC)	+= arc_uart.o

include/uapi/linux/serial_core.h

@@ -215,5 +215,7 @@
 /* Energy Micro efm32 SoC */
 #define PORT_EFMUART   100
 
+/* ARC (Synopsys) on-chip UART */
+#define PORT_ARC       101
 
 #endif /* _UAPILINUX_SERIAL_CORE_H */