I am trying to enable external reference voltage in AD7999 chip using Rcar evaluation board with Linux kernel. (IIO framework)
In the available driver code, there is no option to set the external voltage reference configuration. I tried to enable the D3 bit (REF_SEL) of the 8-bit configuration register but was not successful.
Could you please suggest me the steps to set the REF_SEL bit so that the external reference voltage is selected.