tty: serial: Add RDA8810PL UART driver

Add UART driver for RDA Micro RDA8810PL SoC.
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Olof Johansson <olof@lixom.net>

Documentation/admin-guide/kernel-parameters.txt

@@ -1021,6 +1021,12 @@
 			specified address. The serial port must already be
 			setup and configured. Options are not yet supported.
 
+		rda,<addr>
+			Start an early, polled-mode console on a serial port
+			of an RDA Micro SoC, such as RDA8810PL, at the
+			specified address. The serial port must already be
+			setup and configured. Options are not yet supported.
+
 		smh	Use ARM semihosting calls for early console.
 
 		s3c2410,<addr>

drivers/tty/serial/Kconfig

@@ -1529,6 +1529,25 @@ config SERIAL_OWL_CONSOLE
 	  Say 'Y' here if you wish to use Actions Semiconductor S500/S900 UART
 	  as the system console.
 
+config SERIAL_RDA
+	bool "RDA Micro serial port support"
+	depends on ARCH_RDA || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  This driver is for RDA8810PL SoC's UART.
+	  Say 'Y' here if you wish to use the on-board serial port.
+	  Otherwise, say 'N'.
+
+config SERIAL_RDA_CONSOLE
+	bool "Console on RDA Micro serial port"
+	depends on SERIAL_RDA=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	default y
+	help
+	  Say 'Y' here if you wish to use the RDA8810PL UART as the system
+	  console. Only earlycon is implemented currently.
+
 endmenu
 
 config SERIAL_MCTRL_GPIO

drivers/tty/serial/Makefile

@@ -89,6 +89,7 @@ obj-$(CONFIG_SERIAL_MVEBU_UART)	+= mvebu-uart.o
 obj-$(CONFIG_SERIAL_PIC32)	+= pic32_uart.o
 obj-$(CONFIG_SERIAL_MPS2_UART)	+= mps2-uart.o
 obj-$(CONFIG_SERIAL_OWL)	+= owl-uart.o
+obj-$(CONFIG_SERIAL_RDA)	+= rda-uart.o
 
 # GPIOLIB helpers for modem control lines
 obj-$(CONFIG_SERIAL_MCTRL_GPIO)	+= serial_mctrl_gpio.o

include/uapi/linux/serial_core.h

@@ -281,4 +281,7 @@
 /* MediaTek BTIF */
 #define PORT_MTK_BTIF	117
 
+/* RDA UART */
+#define PORT_RDA	118
+
 #endif /* _UAPILINUX_SERIAL_CORE_H */