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> Cheers, Peter
