On Tue, 17 Oct 2023 16:00:22 +0200 Peter Rosin <peda@xxxxxxxxxx> wrote: > Hi! > > 2023-10-17 at 11:05, Jonathan Cameron wrote: > > On Mon, 16 Oct 2023 12:05:32 +0200 > > Peter Rosin <peda@xxxxxxxxxx> wrote: > >> 2023-10-16 at 10:39, Linus Walleij wrote: > > > > >>> Just raw (with neither offset or rescale) doesn't make sense, since > >> > >> And I don't see why not. That's the crux. > >> > >>> the AFE rescaler does just offsetting and rescaling, in that case the > >>> user should just use the raw channel. Also it would then take > >>> precedence over a processed channel (which applies rescale and > >>> offset internally) which doesn't make sense to me. > >> > >> Why isn't it perfectly fine for a device to provide only a raw > >> channel and then expect that to be interpreted as the real unit? > >> Why would it need a processed channel when no processing is > >> going on? E.g. a device reporting the temp in the expected unit > >> in one of its registers. Or whatever with such a friendly > >> register. > > > > In that case it should report a processed value to indicate that. > > It's admittedly a bit of a corner case given it's not processed by > > the kernel - there is an argument that this (more or less) only > > happens when someone has processed a raw ADC count but in theory > > that's not necessarily true. > > > > There are a few examples of drivers passing through the register value > > as processed in tree - normally when there > > is a microprocessor doing some fusion of signals or similar. > > > > Raw gets reported on it's own in a few other cases, such as when > > there are no known units - that happens for things like light intensity, > > proximity (which is often reflected light intensity). > > For those I'm not sure the rescaler is useful. > > Excellent, thanks for the clarification! > > Reviewed-by: Peter Rosin <peda@xxxxxxxxxx> Thanks, Applied to the fixes-togreg branch of iio.git. I'll just let this sit in linux-next for a day or so before a pull request (I have a few other fixes queued). That will almost certainly get queued for the merge window given timing. Thanks, Jonathan > > Cheers, > Peter
