Hi,

On 2/8/21 2:40 PM, Bastien Nocera wrote:

On Sun, 2021-02-07 at 13:37 +0100, Hans de Goede wrote:

quoted

Add an entry to Documentation/ABI/testing/sysfs-bus-iio for
the new device and channel label sysfs-attribute support.

And document the standardized labels which may be used with proximity
sensors to hint userspace about the intended use of the sensor.

Using labels to differentiate between the multiple proximity sensors
which a modern laptop/tablet may have was discussed in this thread:
https://lore.kernel.org/linux-iio/9f9b0ff6-3bf1-63c4-eb36-901cecd7c4d9@redhat.com/ (local)

As mentioned the "proximity-wifi*" labels are already being used in
this manner on some chromebooks, see e.g.:
arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
arch/arm64/boot/dts/qcom/sc7180-trogdor-lte-sku.dtsi

And the "proximity-palmrest" and "proximity-lap" labels are intended
to be used with the lap and palmrest sensors found in recent Lenovo
ThinkPad models.

Both patches in the series look fine to me.

Thank you for checking.

Is IIO the interface you plan on using to implement the lap detection
for the thinkpad_acpi driver?

ATM both the lap detection and the palmrest proximity detection are
already available using thinkpad_acpi specific sysfs attributes:

[hans@x1 linux]$ cat /sys/bus/platform/devices/thinkpad_acpi/dytc_lapmode 
0
[hans@x1 linux]$ cat /sys/bus/platform/devices/thinkpad_acpi/palmsensor 
1

Which I think you are already aware of ?  These will not be going
anywhere since dropping these would be a userspace ABI break.

With that said, yes the plan is to extend the thinkpad_acpi driver
to also report lap / palmrest proximity through IIO using these labels.

With the idea being that if other drivers / vendor firmwares also will
export similar readings that those will then also use IIO with these
labels for this, so that there is one unified / driver independent
interface which userspace can use to get these readings.

If so, don't forget to set the "nearlevel" property as well.

Ack, I'll make sure that you are on the Cc when the patches for this
get posted.

Regards,

Hans