On Mon, 4 May 2020 12:02:36 +0200 Bastien Nocera <hadess@xxxxxxxxxx> wrote: > On Sat, 2020-05-02 at 19:07 +0100, Jonathan Cameron wrote: > > On Sun, 26 Apr 2020 13:19:09 +0200 > > Bastien Nocera <hadess@xxxxxxxxxx> wrote: > > > > > On Sat, 2020-04-25 at 18:13 +0100, Jonathan Cameron wrote: > > > > On Thu, 23 Apr 2020 14:17:15 +0200 > > > > Gaëtan André <rvlander@xxxxxxxxxxxxxx> wrote: > > > > > > > > > Scale channels are available by axis. For example for > > > > > accelerometers, > > > > > in_accel_x_scale, in_accel_y_scale and in_accel_z_scale are > > > > > available. > > > > > > > > > > However, they should be shared by type as documented in > > > > > Documentation/ABI/testing/sysfs-bus-iio. > > > > > > > > > > For each sensor (acceleros, gyros and magnetos) only one value > > > > > is > > > > > specified > > > > > for all the axes. > > > > > > > > > > Existing, by axis, entries are preserved in order to to leave > > > > > the > > > > > old ABI > > > > > untouched. > > > > As I mentioned in v1, there isn't a strict ABI rule that says > > > > that we > > > > must > > > > do the shared form > > > > > > > > +CC'd Bastien for comment on what userspace is assuming and > > > > whether > > > > we should > > > > push this back to stable or not. > > > > > > I have no idea what the effects of this would be on the ABI, and > > > how > > > this would impact iio-sensor-proxy. > > > > There goes me being lazy ;) > > > > > Code is here though, so it might be best to test it: > > > https://gitlab.freedesktop.org/hadess/iio-sensor-proxy/-/tree/master/src > > > > > > And we accept merge requests :) > > > > Only looks at scale and in_accel_scale > > > > Easy enough to fix... > > > > Note that for some older accelerometers it has to do per channel > > scales btw. > > It used to be hard to have the same range out of the plane of the > > silicon > > than within it, so was common to have sensors with different ranges > > and hence > > scales in z direction from x and y. > > > > I'll apply the kernel patch but good to fix up iio-sensor-proxy as > > well. > > > > I would ideally like Denis to give this a quick sanity check though > > as I'd > > like to give it a stable tag and don't want any unexpected breakage. > > I've made this: > https://gitlab.freedesktop.org/hadess/iio-sensor-proxy/-/merge_requests/306 > which should work just fine for the sensors which have a trigger (the z > scaling was the one applied to all 3 axes). > > What's the name of the file that contains the x/y/z axis scale > information for devices without triggers? For both devices with triggers and without, if they are per axis they should be in_accel_x_scale in_accel_y_scale in_accel_z_scale hmm. It's not in our ABI docs for accel channels (but is for magnetometers). Should fix that... https://elixir.bootlin.com/linux/latest/source/Documentation/ABI/testing/sysfs-bus-iio#L340 In theory the other combinations you can get are in_accel_scale in_scale scale The in scale one tends not to make much sense for accelerometers though so I would hope there are no instances of that in the wild (none in mainline). Shared by direction attributes are tend to apply for things like sampling frequency, not scale. Thanks, Jonathan > > Cheers >
