| Message ID | 20210405203933.17282-3-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: documentation: Document proximity/accel sensor label use | expand |
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@gmail.com> > Cc: Mark Pearson <mpearson@lenovo.com> > Cc: Bastien Nocera <hadess@hadess.net> > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > 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@vger.kernel.org
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. 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@gmail.com> >> Cc: Mark Pearson <mpearson@lenovo.com> >> Cc: Bastien Nocera <hadess@hadess.net> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >> --- >> 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@vger.kernel.org > >
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@gmail.com> > > > Cc: Mark Pearson <mpearson@lenovo.com> > > > Cc: Bastien Nocera <hadess@hadess.net> > > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > > > --- > > > 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@vger.kernel.org > > > > >
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_clock KernelVersion: 4.5 Contact: linux-iio@vger.kernel.org
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" 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@gmail.com> Cc: Mark Pearson <mpearson@lenovo.com> Cc: Bastien Nocera <hadess@hadess.net> Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- Documentation/ABI/testing/sysfs-bus-iio | 7 +++++++ 1 file changed, 7 insertions(+)