serial: Add driver for the Altera UART

Add an UART driver for the UART component available as a SOPC (System on
Programmable Chip) component for Altera FPGAs.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/serial/Kconfig

@@ -1544,4 +1544,35 @@ config SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS
 	  Bypass console output and keep going even if there is no
 	  JTAG terminal connection with the host.
 
+config SERIAL_ALTERA_UART
+	tristate "Altera UART support"
+	select SERIAL_CORE
+	help
+	  This driver supports the Altera softcore UART port.
+
+config SERIAL_ALTERA_UART_MAXPORTS
+	int "Maximum number of Altera UART ports"
+	depends on SERIAL_ALTERA_UART
+	default 4
+	help
+	  This setting lets you define the maximum number of the Altera
+	  UART ports. The usual default varies from board to board, and
+	  this setting is a way of catering for that.
+
+config SERIAL_ALTERA_UART_BAUDRATE
+	int "Default baudrate for Altera UART ports"
+	depends on SERIAL_ALTERA_UART
+	default 115200
+	help
+	  This setting lets you define what the default baudrate is for the
+	  Altera UART ports. The usual default varies from board to board,
+	  and this setting is a way of catering for that.
+
+config SERIAL_ALTERA_UART_CONSOLE
+	bool "Altera UART console support"
+	depends on SERIAL_ALTERA_UART=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Enable a Altera UART port to be the system console.
+
 endmenu

drivers/serial/Makefile

@@ -83,3 +83,4 @@ obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
 obj-$(CONFIG_SERIAL_TIMBERDALE)	+= timbuart.o
 obj-$(CONFIG_SERIAL_GRLIB_GAISLER_APBUART) += apbuart.o
 obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o
+obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o

include/linux/altera_uart.h

+/*
+ * altera_uart.h -- Altera UART driver defines.
+ */
+
+#ifndef	__ALTUART_H
+#define	__ALTUART_H
+
+struct altera_uart_platform_uart {
+	unsigned long mapbase;	/* Physical address base */
+	unsigned int irq;	/* Interrupt vector */
+	unsigned int uartclk;	/* UART clock rate */
+};
+
+#endif /* __ALTUART_H */

include/linux/serial_core.h

@@ -184,6 +184,7 @@
 
 /* Altera UARTs */
 #define PORT_ALTERA_JTAGUART	91
+#define PORT_ALTERA_UART	92
 
 #ifdef __KERNEL__