tty: serial: add Freescale lpuart driver support

Add Freescale lpuart driver support. The lpuart device
can be found on Vybrid VF610 and Layerscape LS-1 SoCs.

Signed-off-by: Jingchang Lu <b35083@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/tty/serial/fsl-lpuart.txt

@@ -0,0 +1,14 @@
+* Freescale low power universal asynchronous receiver/transmitter (lpuart)
+
+Required properties:
+- compatible : Should be "fsl,<soc>-lpuart"
+- reg : Address and length of the register set for the device
+- interrupts : Should contain uart interrupt
+
+Example:
+
+uart0: serial@40027000 {
+	       compatible = "fsl,vf610-lpuart";
+	       reg = <0x40027000 0x1000>;
+	       interrupts = <0 61 0x00>;
+       };

drivers/tty/serial/Kconfig

@@ -1483,6 +1483,20 @@ config SERIAL_RP2_NR_UARTS
 	  If multiple cards are present, the default limit of 32 ports may
 	  need to be increased.
 
+config SERIAL_FSL_LPUART
+	tristate "Freescale lpuart serial port support"
+	select SERIAL_CORE
+	help
+	  Support for the on-chip lpuart on some Freescale SOCs.
+
+config SERIAL_FSL_LPUART_CONSOLE
+	bool "Console on Freescale lpuart serial port"
+	depends on SERIAL_FSL_LPUART=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you have enabled the lpuart serial port on the Freescale SoCs,
+	  you can make it the console by answering Y to this option.
+
 endmenu
 
 endif # TTY

drivers/tty/serial/Makefile

@@ -85,3 +85,4 @@ obj-$(CONFIG_SERIAL_AR933X)   += ar933x_uart.o
 obj-$(CONFIG_SERIAL_EFM32_UART) += efm32-uart.o
 obj-$(CONFIG_SERIAL_ARC)	+= arc_uart.o
 obj-$(CONFIG_SERIAL_RP2)	+= rp2.o
+obj-$(CONFIG_SERIAL_FSL_LPUART)	+= fsl_lpuart.o