On 10/29/24 9:38 AM, Jonathan Cameron wrote: > On Tue, 29 Oct 2024 13:20:06 +0100 > Ricardo Ribalda <ribalda@xxxxxxxxxxxx> wrote: > >> Hi Jonathan >> >> On Mon, 28 Oct 2024 at 21:34, Jonathan Cameron <jic23@xxxxxxxxxx> wrote: >>> >>> On Mon, 28 Oct 2024 10:12:23 +0000 >>> Ricardo Ribalda <ribalda@xxxxxxxxxxxx> wrote: >>> >>>> Add a new channel type representing if the user's attention state to the >>>> the system. This usually means if the user is looking at the screen or >>>> not. >>>> >>>> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx> >>>> --- >>>> Documentation/ABI/testing/sysfs-bus-iio | 7 +++++++ >>>> drivers/iio/industrialio-core.c | 1 + >>>> include/uapi/linux/iio/types.h | 1 + >>>> tools/iio/iio_event_monitor.c | 2 ++ >>>> 4 files changed, 11 insertions(+) >>>> >>>> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio >>>> index 89943c2d54e8..d5a2f93bd051 100644 >>>> --- a/Documentation/ABI/testing/sysfs-bus-iio >>>> +++ b/Documentation/ABI/testing/sysfs-bus-iio >>>> @@ -2339,3 +2339,10 @@ KernelVersion: 6.10 >>>> Contact: linux-iio@xxxxxxxxxxxxxxx >>>> Description: >>>> The value of current sense resistor in Ohms. >>>> + >>>> +What: /sys/.../iio:deviceX/in_attention_raw >>>> +KernelVersion: 6.13 >>>> +Contact: linux-iio@xxxxxxxxxxxxxxx >>>> +Description: >>>> + Boolean value representing the user's attention to the system. >>>> + This usually means if the user is looking at the screen or not. >>> >>> Hmm. I should have thought of this when I replied to suggest a new channel type. >>> The question is 'units' for a decision. >>> >>> Last time we hit something like this where processing is used to make a decision >>> we decided to at least allow for the concept of 'certainty'. >>> >>> The idea being that smarter sensors would tell us something about how sure they >>> are that the attention is on the device. >>> The analogy being with activity detection. See in_activity_walking_input >>> in Documentation/ABI/testing/sysfs-bus-iio >>> >>> Do you think that would be appropriate here as well? For this device >>> it would take the values 0 and 100 rather than 0 and 1. >> >> For the particular device that I want to support, they are giving me a >> value of 1 and 0, and the example from usb.org seems to work the same >> way (Logical Maximum of 1) >> https://www.usb.org/sites/default/files/hutrr107-humanpresenceattention_1.pdf >> >> I have no problem multiplying my value by 100 if you think there will >> be a use case for that. It will not have a major performance impact on >> the driver. > Same was true (0 or 1) for the activity classification but I'm not > keen on certainty :) So lets' copy that precedence and *100 > > And I assume we would want this to be in_attention_input (processed), not in_attention_raw.