Hi, On 2/15/21 1:39 PM, Jonathan Cameron wrote: > On Fri, 12 Feb 2021 19:58:47 +0100 > Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > >> Hi, >> >> On 2/12/21 7:46 PM, Jonathan Cameron wrote: >>> On Sun, 7 Feb 2021 13:37:19 +0100 >>> Hans de Goede <hdegoede@xxxxxxxxxx> wrote: >>> >>>> 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@xxxxxxxxxx/ >>>> >>>> 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. >>>> >>>> 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 | 41 +++++++++++++++++++++++++ >>>> 1 file changed, 41 insertions(+) >>>> >>>> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio >>>> index 35289d47d6cb..f2f090f8bd2f 100644 >>>> --- a/Documentation/ABI/testing/sysfs-bus-iio >>>> +++ b/Documentation/ABI/testing/sysfs-bus-iio >>>> @@ -33,6 +33,47 @@ Description: >>>> Description of the physical chip / device for device X. >>>> Typically a part number. >>>> >>>> +What: /sys/bus/iio/devices/iio:deviceX/label >>>> +What: /sys/bus/iio/devices/iio:deviceX/in_*_label >>>> +What: /sys/bus/iio/devices/iio:deviceX/out_*_label >>> >>> I was a bit in two minds about this from an organizational point of view. >>> 1) Whether to separate the general label where position tends to make sense >>> from the channel labels. May be something we want to do in future but we can probably >>> let that go for now. >>> 2) Whether to allow such broad wild cards for the channels. >>> Whilst in theory any channel can have a label we normally only document ABI >>> that actually exists (mostly to know what we might break if we change anything :) >>> Still I can't see any way we can change this without breakage so in this >>> one case let's let the broad wild card go in. >>> >>> This comes unstuck on the fact it overlaps with existing more specific Docs. >>> >>> So can you pull the channel part out of here for v2. >>> /sys/bus/iio/devices/iio:deviceX/in_voltageY_label >>> /sys/bus/iio/devices/iio:deviceX/in_anglY_label >> >> The problem is that these labels may either be used on a whole device, >> which is certainly the case with the accelerometers in patch 2/2 where >> the x y and z channels obviously all are either "accel-base" or >> "accel-display". >> >> Where as for proximity sensors the labels could be either applied at the >> device level, or at a channel level. >> >> The existing chromebook proximity usage is applying a label for this >> at the device level. >> >> This does mean that atm all users of this are using device-level labels; > > Not at all, but some (possibly all?) are separately documented in two > existing entries. The generic version you propose overlaps with them > and that is what I'd like to avoid. > > We could group these into the same 'catch all' element, but I suspect > the text will just grow too large over time, so I'd like to keep them > as broken up as possible. > > What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_label > What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_label > > What: /sys/bus/iio/devices/iio:deviceX/in_anglY_label > >> and maybe I'm reading too much in your request. I guess that for now >> I can just drop these lines for v2 : >> >> What: /sys/bus/iio/devices/iio:deviceX/in_*_label >> What: /sys/bus/iio/devices/iio:deviceX/out_*_label >> >> Is that what you have in mind ? >> >> Or do you want me to split this up in a proximity sensor case and an >> accel case, and group both cases together with other proximity / accel >> sensor attributes ? > > Yes, that would be ideal for the cases where we have separate > channel labels, but if we aren't using them today, lets introduce them > when they are needed. Right, so atm we do not have any channel labels only device labels, which means there is only 1 "What:". What: /sys/bus/iio/devices/iio:deviceX/label For which v1 (this version) of this series adds a single large text block which covers both proximity and accelerometers. So just to be clear, you want me to split this, resulting in 2 entries with identical "What:" labels: What: /sys/bus/iio/devices/iio:deviceX/label And then group the 2 text blocks together with other proximity sensor attributes, resp. other accelerometer attributes ? Regards, Hans > > Jonathan > > >> >> Regards, >> >> Hans >> >> >> >> >>> Jonathan >>>> +KernelVersion: 5.8 >>>> +Contact: linux-iio@xxxxxxxxxxxxxxx >>>> +Description: >>>> + Optional symbolic label for a device or a channel. >>>> + This is useful for userspace to be able to better identify an >>>> + individual device or channel. >>>> + >>>> + The contents of the label are free-form, but there are some >>>> + standardized uses: >>>> + >>>> + For proximity sensors which give the proximity (of a person) to >>>> + a certain wlan or wwan antenna the following standardized labels >>>> + are used: >>>> + >>>> + * "proximity-wifi" >>>> + * "proximity-lte" >>>> + * "proximity-wifi-lte" >>>> + * "proximity-wifi-left" >>>> + * "proximity-wifi-right" >>>> + >>>> + These are used to indicate to userspace that these proximity >>>> + sensors may be used to tune transmit power to ensure that >>>> + Specific Absorption Rate (SAR) limits are honored. >>>> + The "-left" and "-right" labels are for devices with multiple >>>> + antennas. >>>> + >>>> + In some laptops/tablets the standardized proximity sensor labels >>>> + instead indicate proximity to a specific part of the device: >>>> + >>>> + * "proximity-palmrest" indicates proximity to the keyboard's palmrest >>>> + * "proximity-palmrest-left" indicates proximity to the left part of the palmrest >>>> + * "proximity-palmrest-right" indicates proximity to the right part of the palmrest >>>> + * "proximity-lap" indicates the device is being used on someone's lap >>>> + >>>> + Note "proximity-lap" is special in that its value may be >>>> + calculated by firmware from other sensor readings, rather then >>>> + being a raw sensor reading. >>>> + >>>> What: /sys/bus/iio/devices/iio:deviceX/current_timestamp_clock >>>> KernelVersion: 4.5 >>>> Contact: linux-iio@xxxxxxxxxxxxxxx >>> >> >
