Re: [PATCH 0/2] iio: driver for Semtech SX9500

[Vlad Dogaru <vlad.dogaru@intel.com>]

On Tue, Nov 18, 2014 at 10:12:32PM +0000, Jonathan Cameron wrote:
> On 18/11/14 22:02, Jonathan Cameron wrote:
> > On 17/11/14 15:25, Peter Meerwald wrote:
> >>
> >>> The device does not estimate distance, it only outputs a single bit which
> >>> indicates proximity.  We use 0 to mean that an object is close and 1 otherwise,
> >>> sort of an uncalibrated distance.  From what I understand in the ABI
> >>> specification, this is allowed.
> >>
> >> perhaps the input subsystem would be a better fit for this driver/device?
> >> what is it typically used for?

We have this part listed under "proximity sensors", so I thought it
belongs in iio.  We don't have a device that actually uses the SX9500,
I'm using an evaluation board and an I2C bridge right now :)

> > Whilst it may be the case that this particular one might have a reasonable
> > home in input, these are often integrated with ambient light sensors
> > and as such we already have a quite a few proximity sensors in IIO...
> > 
> > Interestingly there is one obvious proximity sensor in input and that
> > is a dual ambient light/ proximity part though I can't see any way
> > of reading the light side of it.  Interesting...
> Note that, given it describes itself as a button trip I can entirely see
> your point with this one!  I wrote my reply before opening the datasheet.
> oops.
> 
> The device does seem to provide access to measurements related to
> the capacitance sensed so might be rather more flexible than just
> a button though.

I kept away from the measurements because they look like uncalibrated
information.  Then again, so is "0/1", as I mentioned initially.

Would you find it acceptable to expose the raw measures through
in_priximity0_raw, and keep the events as they are?  That way the raw
readings can give some basic indication of distance, while still being
able to use the events for near/far notification.

Thanks,
Vlad