On Wed, 2023-06-07 at 15:52 +0100, Jonathan Cameron wrote: > Not 'official' though it is fairly commonly used, but the documented > ABI in > Documentation/ABI/testing/sysfs-bus-iio* > is and these aren't there either. > > I'm not 100% sure this is the right way to solve this ABI gap though > so need to have a bit of a think about it. Using a modifier means we > can't > use them for anything else, so need to consider if there are other > modifiers > (or it has meaning for differential channels) when deciding if this is > an ABI we want to add. The naming of the modifiers is also somewhat confusing. The HW registers represent the DFT of the input signal, which together with a gain factor is used to calculate the impedance. Dimensionally the quantities are admittances. "voltage_real" and "voltage_imag" are therefore not quite fitting. Also the sweep setup commands are only run once per buffer (in ad5933_ring_preenable). This means a buffer can only be used for one sweep and then has to be disabled and enabled again. As the driver does not implement any triggers this is right now the only way to start a measurement. Do you think it would make sense to implement a user-space trigger to start a measurement sweep? This would mean that a buffer can be reused. Right now the "iio_readdev" test program from libiio does not work due to this behavior. I don't know how this is handled on other IIO drivers. Lastly, should I CC the original author (Michael Hennerich) going forward? Thanks!
