serial: New serial driver MAX310X

This driver is a replacement for a MAX3107 driver with a lot of
improvements and new features.
The main differences from the old version:
- Using the regmap.
- Using devm_XXX-related functions.
- The use of threaded IRQ with IRQF_ONESHOT flag allows the driver to
  the hardware that supports only level IRQ.
- Improved error handling of serial port, improved FIFO handling,
  improved hardware & software flow control.
- Advanced flags allows turn on RS-485 mode (Auto direction control).
- Ability to load multiple instances of drivers.
- Added support for MAX3108.
- GPIO support.
- Driver is quite ready for adding I2C support and support other ICs
  with compatible registers set (MAX3109, MAX14830).

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/Kconfig

@@ -257,12 +257,19 @@ config SERIAL_MAX3100
 	help
 	  MAX3100 chip support
 
-config SERIAL_MAX3107
-	tristate "MAX3107 support"
+config SERIAL_MAX310X
+	bool "MAX310X support"
 	depends on SPI
 	select SERIAL_CORE
+	select REGMAP_SPI if SPI
+	default n
 	help
-	  MAX3107 chip support
+	  This selects support for an advanced UART from Maxim (Dallas).
+	  Supported ICs are MAX3107, MAX3108.
+	  Each IC contains 128 words each of receive and transmit FIFO
+	  that can be controlled through I2C or high-speed SPI.
+
+	  Say Y here if you want to support this ICs.
 
 config SERIAL_DZ
 	bool "DECstation DZ serial driver"

drivers/tty/serial/Makefile

@@ -28,7 +28,7 @@ obj-$(CONFIG_SERIAL_BFIN) += bfin_uart.o
 obj-$(CONFIG_SERIAL_BFIN_SPORT) += bfin_sport_uart.o
 obj-$(CONFIG_SERIAL_SAMSUNG) += samsung.o
 obj-$(CONFIG_SERIAL_MAX3100) += max3100.o
-obj-$(CONFIG_SERIAL_MAX3107) += max3107.o
+obj-$(CONFIG_SERIAL_MAX310X) += max310x.o
 obj-$(CONFIG_SERIAL_IP22_ZILOG) += ip22zilog.o
 obj-$(CONFIG_SERIAL_MUX) += mux.o
 obj-$(CONFIG_SERIAL_68328) += 68328serial.o