Hi, On 11/20/20 10:59 AM, Jonathan Cameron wrote: > On Thu, 19 Nov 2020 16:39:07 +0100 > Hans de Goede <hdegoede@xxxxxxxxxx> wrote: >>>>>>>> On 2020-10-03 10:02 a.m., Hans de Goede wrote: >>>>>>>>> Hi All, >>>>>>>>> >>>>>>>>> Modern laptops can have various sensors which are kinda >>>>>>>>> like proximity sensors, but not really (they are more >>>>>>>>> specific in which part of the laptop the user is >>>>>>>>> proximate to). >>>>>>>>> >>>>>>>>> Specifically modern Thinkpad's have 2 readings which we >>>>>>>>> want to export to userspace, and I'm wondering if we >>>>>>>>> could use the IIO framework for this since these readings >>>>>>>>> are in essence sensor readings: >>>>>>>>> >>>>>>>>> 1. These laptops have a sensor in the palm-rests to >>>>>>>>> check if a user is physically proximate to the device's >>>>>>>>> palm-rests. This info will be used by userspace for WWAN >>>>>>>>> functionality to control the transmission level safely. >>>>>>>>> >>>>>>>>> A patch adding a thinkpad_acpi specific sysfs API for this >>>>>>>>> is currently pending: >>>>>>>>> https://patchwork.kernel.org/patch/11722127/ >>>>>>>>> >>>>>>>>> But I'm wondering if it would not be better to use >>>>>>>>> IIO to export this info. <snip> >>> On newer ARM we use "label" attribute in DTS: >>> >>> arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi >>> >>> ap_sar_sensor: proximity@28 { >>> compatible = "semtech,sx9310"; >>> reg = <0x28>; >>> #io-channel-cells = <1>; >>> pinctrl-names = "default"; >>> pinctrl-0 = <&p_sensor_int_l>; >>> >>> interrupt-parent = <&tlmm>; >>> interrupts = <24 IRQ_TYPE_LEVEL_LOW>; >>> >>> vdd-supply = <&pp3300_a>; >>> svdd-supply = <&pp1800_prox>; >>> >>> status = "disabled"; >>> label = "proximity-wifi"; >>> }; >> >> Hmm, interesting. I did not know iio-devices could >> have a label sysfs attribute (nor that that could be >> set through device-tree). I was thinking about adding >> an in_proximity_location sysfs attribute. But using >> labels (and standardizing a set of label names) will >> work nicely too. > > It's fairly new. Note we also have per channel labels > though they are 'very new'. Might be handy if the sensors > appear as a single device despite being spread over the > laptop. Interesting, the thinkpad_acpi stuff currently has 2 proximity(ish) sensors: 1. Laptop is close to (on) someones lap 2. Someone's arms are resting on or close to the palmrest Ideally we would indeed register 1 iio-dev with separate channels for this, rather then having to register 2 (and the future maybe even more) iio-devs for this. Can you give a pointer to docs / examples of using a label per channel ? >> Is there a know set of labels which ChromeOS is currently >> using? If we are going to use labels for this it would >> be good IMHO to define a set of standard labels for >> this in say Documentation/ABI/testing/sysfs-bus-iio-labels. > > If you do want to do this, please just put it under sysfs-bus-iio > doc. I want this to be in the top level doc. Ok, ack. Dmitry, can you perhaps dig up a full-list of labels which ChromeOS is currently using to identify proximity sensors for e.g. SAR related use? Regards, Hans
