serial: sc16is7xx

The SC16IS7xx is a slave I2C-bus/SPI interface to a single-channel
high performance UART. The SC16IS7xx's internal register set is
backward-compatible with the widely used and widely popular 16C450.

The SC16IS7xx also provides additional advanced features such as
auto hardware and software flow control, automatic RS-485 support, and
software reset.
Signed-off-by: Jon Ringle <jringle@gridpoint.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/Kconfig

@@ -1178,6 +1178,15 @@ config SERIAL_SCCNXP_CONSOLE
 	help
 	  Support for console on SCCNXP serial ports.
 
+config SERIAL_SC16IS7XX
+	tristate "SC16IS7xx serial support"
+	select SERIAL_CORE
+	select REGMAP_I2C if I2C
+	help
+	  This selects support for SC16IS7xx serial ports.
+	  Supported ICs are SC16IS740, SC16IS741, SC16IS750, SC16IS752,
+	  SC16IS760 and SC16IS762.
+
 config SERIAL_BFIN_SPORT
 	tristate "Blackfin SPORT emulate UART"
 	depends on BLACKFIN

drivers/tty/serial/Makefile

@@ -51,6 +51,7 @@ obj-$(CONFIG_SERIAL_MPSC) += mpsc.o
 obj-$(CONFIG_SERIAL_SB1250_DUART) += sb1250-duart.o
 obj-$(CONFIG_ETRAX_SERIAL) += crisv10.o
 obj-$(CONFIG_SERIAL_SCCNXP) += sccnxp.o
+obj-$(CONFIG_SERIAL_SC16IS7XX) += sc16is7xx.o
 obj-$(CONFIG_SERIAL_JSM) += jsm/
 obj-$(CONFIG_SERIAL_TXX9) += serial_txx9.o
 obj-$(CONFIG_SERIAL_VR41XX) += vr41xx_siu.o

include/uapi/linux/serial_core.h

@@ -241,4 +241,7 @@
 /* MEN 16z135 UART */
 #define PORT_MEN_Z135	107
 
+/* SC16IS74xx */
+#define PORT_SC16IS7XX   108
+
 #endif /* _UAPILINUX_SERIAL_CORE_H */