Hi George, On Sun, May 28, 2023 at 11:52 PM George Stark <GNStark@xxxxxxxxxxxxxx> wrote: [...] > > Based on the limited description we have here, I'm not understanding why > > you don't just express this as a set of channels. One channel per mux > > setting, with the in_voltageX_label providing the information on what the > > channel is connected to. > > > > This is an interesting facility, so good to enable for high precision calibration > > but we still want to map it to standards signals. Userspace doesn't > > care that these are all being measured via the same input 7 - which > > is itself probably an input to a MUX. > > > > Jonathan > > Hello Jonathan > > Thanks for the review. > > Your idea of exposing the mux setting as iio channels is very > interesting and at least worth trying. > The sysfs approach was chosen because of the code changes are simple and > neat (compare to channels approach). > Also calibration by using those mux inputs are already supported in the > driver (performed at probe stage) so I expect very special usecases for > those mux settings like debug or device production stage tests. In those > usescases hardware specific knowledge is required anyway. Another downside to the debugfs approach is user support: If someone reports odd values on ADC channel 7 then we need to make sure to double check if the mux has been altered from userspace (the calibration during initialization ensures to leave channel 7 in a consistent state, while a user may change the mux, forget about it and then complain that values are wrong). Best regards, Martin
