Hi,
As discussed before the direct register access interface is not meant for application development. It is for debugging only. Directly modifying the registers can result in undefined behavior and malfunction. We do not recommend that you directly access the registers but rather use the provided APIs to archive a certain task.
On Linux you can enable or disable a channel by going to the sysfs node for the IIO device you want to sample from and go to the scan_elements subfolder and write a 1 or a zero to in_voltageX_en where X is the channel you want to enable. For a more detailed description please check the documentation for the Linux driver for the AXI ADC core.
- Lars