On Fri, Nov 17, 2023 at 12:22 PM Sicelo <absicsz@???> wrote:
>
> Hi
>
> Some phones have 1-bit proximity sensors, which simply toggle a GPIO
> line to indicate that an object is near or far. Thresholds are set at
> hardware level. One such sensor is OSRAM SFH 7741 [1], which is used on
> the Nokia N900.
>
> It is currently exported over evdev, emitting the SW_FRONT_PROXIMITY key
> code [2].
>
> So the question is: should a new, general purpose iio-gpio driver be
> written, that would switch such a proximity sensor to the iio framework?
> Or evdev is really the best place to support it?
>
> There are a couple of people who are willing to write such an iio
> driver, if iio is the way to go.
>
> Regards,
> Sicelo
>
> [1] https://media.digikey.com/pdf/Data%20Sheets/Osram%20PDFs/SFH_7741.pdf
> [2] https://elixir.bootlin.com/linux/v6.6.1/source/arch/arm/boot/dts/ti/omap/omap3-n900.dts#L111
>
Since this is really a proximity switch (it is either on or off)
rather than measuring a proximity value over a continuous range, it
doesn't seem like a good fit for the iio subsystem. If the sensor is
on a phone, then it is likely to detect human presence so the input
subsystem does seem like the right one for that application.

More at https://www.kernel.org/doc/html/latest/driver-api/iio/intro.html