i2c: New bus driver for the TAOS evaluation modules

This is a new I2C bus driver for the TAOS evaluation modules. Developped
and tested on the TAOS TSL2550 EVM.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

Documentation/i2c/busses/i2c-taos-evm

@@ -0,0 +1,46 @@
+Kernel driver i2c-taos-evm
+
+Author: Jean Delvare <khali@linux-fr.org>
+
+This is a driver for the evaluation modules for TAOS I2C/SMBus chips.
+The modules include an SMBus master with limited capabilities, which can
+be controlled over the serial port. Virtually all evaluation modules
+are supported, but a few lines of code need to be added for each new
+module to instantiate the right I2C chip on the bus. Obviously, a driver
+for the chip in question is also needed.
+
+Currently supported devices are:
+
+* TAOS TSL2550 EVM
+
+For addtional information on TAOS products, please see
+  http://www.taosinc.com/
+
+
+Using this driver
+-----------------
+
+In order to use this driver, you'll need the serport driver, and the
+inputattach tool, which is part of the input-utils package. The following
+commands will tell the kernel that you have a TAOS EVM on the first
+serial port:
+
+# modprobe serport
+# inputattach --taos-evm /dev/ttyS0
+
+
+Technical details
+-----------------
+
+Only 4 SMBus transaction types are supported by the TAOS evaluation
+modules:
+* Receive Byte
+* Send Byte
+* Read Byte
+* Write Byte
+
+The communication protocol is text-based and pretty simple. It is
+described in a PDF document on the CD which comes with the evaluation
+module. The communication is rather slow, because the serial port has
+to operate at 1200 bps. However, I don't think this is a big concern in
+practice, as these modules are meant for evaluation and testing only.

drivers/i2c/busses/Kconfig

@@ -513,6 +513,22 @@ config I2C_SIS96X
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-sis96x.
 
+config I2C_TAOS_EVM
+	tristate "TAOS evaluation module"
+	depends on EXPERIMENTAL
+	select SERIO
+	select SERIO_SERPORT
+	default n
+	help
+	  This supports TAOS evaluation modules on serial port. In order to
+	  use this driver, you will need the inputattach tool, which is part
+	  of the input-utils package.
+
+	  If unsure, say N.
+
+	  This support is also available as a module.  If so, the module
+	  will be called i2c-taos-evm.
+
 config I2C_STUB
 	tristate "I2C/SMBus Test Stub"
 	depends on EXPERIMENTAL && m

drivers/i2c/busses/Makefile

@@ -44,6 +44,7 @@ obj-$(CONFIG_I2C_SIS5595)	+= i2c-sis5595.o
 obj-$(CONFIG_I2C_SIS630)	+= i2c-sis630.o
 obj-$(CONFIG_I2C_SIS96X)	+= i2c-sis96x.o
 obj-$(CONFIG_I2C_STUB)		+= i2c-stub.o
+obj-$(CONFIG_I2C_TAOS_EVM)	+= i2c-taos-evm.o
 obj-$(CONFIG_I2C_TINY_USB)	+= i2c-tiny-usb.o
 obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
 obj-$(CONFIG_I2C_ACORN)		+= i2c-acorn.o