i2c/busses: Add support for Diolan U2C-12 USB-I2C adapter

This patch adds support for the Diolan U2C-12 USB-I2C adapter.
It also updates MAINTAINERS to list the author as maintainer.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

Documentation/i2c/busses/i2c-diolan-u2c

+Kernel driver i2c-diolan-u2c
+
+Supported adapters:
+  * Diolan U2C-12 I2C-USB adapter
+    Documentation:
+	http://www.diolan.com/i2c/u2c12.html
+
+Author: Guenter Roeck <guenter.roeck@ericsson.com>
+
+Description
+-----------
+
+This is the driver for the Diolan U2C-12 USB-I2C adapter.
+
+The Diolan U2C-12 I2C-USB Adapter provides a low cost solution to connect
+a computer to I2C slave devices using a USB interface. It also supports
+connectivity to SPI devices.
+
+This driver only supports the I2C interface of U2C-12. The driver does not use
+interrupts.
+
+
+Module parameters
+-----------------
+
+* frequency: I2C bus frequency

MAINTAINERS

@@ -2093,6 +2093,12 @@ F:	Documentation/serial/digiepca.txt
 F:	drivers/char/epca*
 F:	drivers/char/digi*
 
+DIOLAN U2C-12 I2C DRIVER
+M:	Guenter Roeck <guenter.roeck@ericsson.com>
+L:	linux-i2c@vger.kernel.org
+S:	Maintained
+F:	drivers/i2c/busses/i2c-diolan-u2c.c
+
 DIRECTORY NOTIFICATION (DNOTIFY)
 M:	Eric Paris <eparis@parisplace.org>
 S:	Maintained

drivers/i2c/busses/Kconfig

@@ -648,6 +648,16 @@ config I2C_EG20T
 
 comment "External I2C/SMBus adapter drivers"
 
+config I2C_DIOLAN_U2C
+	tristate "Diolan U2C-12 USB adapter"
+	depends on USB
+	help
+	  If you say yes to this option, support will be included for Diolan
+	  U2C-12, a USB to I2C interface.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-diolan-u2c.
+
 config I2C_PARPORT
 	tristate "Parallel port adapter"
 	depends on PARPORT

drivers/i2c/busses/Makefile

@@ -64,6 +64,7 @@ obj-$(CONFIG_I2C_XILINX)	+= i2c-xiic.o
 obj-$(CONFIG_I2C_EG20T)         += i2c-eg20t.o
 
 # External I2C/SMBus adapter drivers
+obj-$(CONFIG_I2C_DIOLAN_U2C)	+= i2c-diolan-u2c.o
 obj-$(CONFIG_I2C_PARPORT)	+= i2c-parport.o
 obj-$(CONFIG_I2C_PARPORT_LIGHT)	+= i2c-parport-light.o
 obj-$(CONFIG_I2C_TAOS_EVM)	+= i2c-taos-evm.o