On Mon, 2021-04-05 at 22:39 +0200, Hans de Goede wrote: > Some 2-in-1 laptops / convertibles with 360° (yoga-style) hinges, > have 2 accelerometers, 1 in their base and 1 in their display. > > In many cases the kernel can detect the location of each > accelerometer > based on e.g. information from the ACPI tables. > > It is important for userspace to know the location of the 2 > accelerometers. > Rather then adding a new sysfs-attribute for this we can relay this > information to userspace by using standardized label strings for > this. > This mirrors how this is done for proximity sensors. > > This commit documents 2 new standardized label strings for this > purpose: > "accel-base" > "accel-display" If we have a combined proximity and accelerometer sensor (which wouldn't be unheard off with sensor hubs being used), how are multiple labels, say "proximity-wifi" and "accel-base" documented? I think that it might be worth using a separate sysfs attribute for this, say "location" which would have "display" or "base" as a value, and which iio-sensor-proxy could already consume. This would also make it easier to funnel values from DeviceTree or ACPI to udev and/or a single sysfs kernel attribute one-to-one. Cheers > > Note the "base" and "display" suffixes were chosen to match the > values > used for the systemd/udev hwdb.d/60-sensor.hwdb file's ACCEL_LOCATION > property. > > Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> > Cc: Mark Pearson <mpearson@xxxxxxxxxx> > Cc: Bastien Nocera <hadess@xxxxxxxxxx> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > --- > Documentation/ABI/testing/sysfs-bus-iio | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio > b/Documentation/ABI/testing/sysfs-bus-iio > index 7379e40d862d..b7529bca83f5 100644 > --- a/Documentation/ABI/testing/sysfs-bus-iio > +++ b/Documentation/ABI/testing/sysfs-bus-iio > @@ -72,6 +72,13 @@ Description: > calculated by firmware from other sensor readings, > rather then > being a raw sensor reading. > > + For accelerometers used in 2-in-1s with 360° (yoga- > style) hinges, > + which have an accelerometer in both their base and > their display, > + the following standardized labels are used: > + > + * "accel-base" > + * "accel-display" > + > What: /sys/bus/iio/devices/iio:deviceX/current_timestamp_cl > ock > KernelVersion: 4.5 > Contact: linux-iio@xxxxxxxxxxxxxxx
