On Fri, 2021-04-16 at 13:05 +0200, Hans de Goede wrote: > Hi, > > On 4/16/21 12:56 PM, Bastien Nocera wrote: > > 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? > > Sensor hubs typically use one iio device per sensor, see e.g. > how HID-sensors work. And if a device which does not use separate > iio-devices per sensor shows up then the plan is to use per > channel-labels which are already supported by iio. OK. > > Regards, > > Hans > > > > > > 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_timestam > > > p_cl > > > ock > > > KernelVersion: 4.5 > > > Contact: linux-iio@xxxxxxxxxxxxxxx > > > > >
