Atmel AT91 I2C Two-Wire interface (TWI)

modulename: i2c-at91.ko

configname: CONFIG_I2C_AT91

Linux Kernel Configuration
└─>Device Drivers
└─>I2C support
└─>I2C Hardware Bus support
└─>Atmel AT91 I2C Two-Wire interface (TWI)
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This supports the use of the I2C interface on Atmel AT91
processors.

This driver is BROKEN because the controller which it uses
will easily trigger RX overrun and TX underrun errors. Using
low I2C clock rates may partially work around those issues
on some systems. Another serious problem is that there is no
documented way to issue repeated START conditions, as needed
to support combined I2C messages. Use the i2c-gpio driver
unless your system can cope with those limitations.

source code:
depends
CONFIG_ARCH_AT91
CONFIG_BROKEN
CONFIG_EXPERIMENTAL
CONFIG_I2C