CHAN_MASK_TOUCHSCREEN_4WIRE  231 drivers/iio/adc/at91_adc.c #define CHAN_MASK_TOUCHSCREEN_4WIRE	(0xf << 0)
CHAN_MASK_TOUCHSCREEN_4WIRE  135 include/linux/mfd/mxs-lradc.h #define CHAN_MASK_TOUCHSCREEN_4WIRE	(0xf << 2)