When you consider to use the analog input (AIN0 to AIN6), be careful!
On my board with kernel 3.8.13 I get (open lines AIN0 - 6, AIN7 connected to 3.3V * 1/2)
# cat /sys/devices/ocp.2/helper.14/AIN*
which first made me think these are digit values and the maximum input voltage may be higher than described (1.8 V).
But instead these are values computed by the kernel driver. It converts the raw data to mV values, rounded as !!! integers !!! (not floats). (This also means 2.2 bits get lost!)
You can receive the raw data by
# cat /sys/bus/iio/devices/iio\:device0/in_voltage*_raw