In linux/drivers/iio/adc/xilinx-xadc-core.c (line 1008++), both vccint and vccaux refer to same register XADC_REG_VCCINT. XADC_CHAN_VOLTAGE(0, 9, XADC_REG_VCCINT, "vccint", true), XADC_CHAN_VOLTAGE(1, 10, XADC_REG_VCCINT, "vccaux", true),