> There is no documented mapping from the 32 possible values of the > IO_IMPEDANCE_CTRL field to values in the range 35-70 ohms There have been a few active TI engineers submitting patches to TI PHY drivers. Please could you reach out to them and ask if they can provide documentation. Having magic values in DT is not the preferred why to use it. Ideally you should store Ohms in the cell and convert to the register value. Andrew