i2c- expender :
# find /sys -iname "*i2c*"
> /sys/devices/platform/i2c-gpio
> /sys/devices/platform/i2c-gpio/i2c-adapter
> /sys/devices/platform/i2c-gpio/i2c-adapter/i2c-0
> /sys/devices/platform/i2c-gpio/i2c-adapter/i2c-0/i2c-0
> /sys/bus/platform/devices/i2c-gpio
> /sys/bus/platform/drivers/i2c-gpio
> /sys/bus/platform/drivers/i2c-gpio/i2c-gpio
> /sys/bus/i2c
> /sys/class/i2c-adapter
> /sys/class/i2c-adapter/i2c-0
> /sys/class/i2c-dev
> /sys/class/i2c-dev/i2c-0
> /sys/module/i2c_algo_bit