RE: Proposed addition to 'IIO interface' for color light sensing devices

From: Jon Brenner
Date: Wed Apr 04 2012 - 11:00:41 EST


Replies in-line,


> -----Original Message-----
> From: Jonathan Cameron [mailto:jic23@xxxxxxxxx]
> Sent: Wednesday, April 04, 2012 3:40 AM
> To: Jon Brenner
> Cc: jic23@xxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx;
linux-iio@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: Proposed addition to 'IIO interface' for color light
sensing devices
>
> Not sure who else would be interested in this discussion so if anyone
can cc any
> interested parties that would be great! (
> > I would like to propose the following addition to the 'IIO device
> > interface' for color light sensing devices to accommodate CCT (AKA
> > color
> > temperature) and access to the raw RGB channel data for user
analysis.
> >
> > IIO channel type name: CCT
> >
> > The CCT ABI should be documented similar to as follows:
> > In sys-bus-iio-light:
> > What: /sys/bus/iio/devices/device[n]/cct[_input|_raw]
> > KernelVersion: 3.3.0
> > Contact: linux-iio@xxxxxxxxxxxxxxx
> > Description:
> > This should return the correlated color temperature from
the
> RGBC
> > color sensor
> > expressed as SI unit (degree kelvin).
> > If it comes back in SI units, it should also
include_input else it
> > should include _raw to signify it is not in SI units.
> Works for me though the formatting of the above is somewhat different
from
> our current docs...
> >
> > IIO modifiers:
> > IIO_MOD_LIGHT_RED
> > IIO_MOD_LIGHT_GREEN
> > IIO_MOD_LIGHT_BLUE
> So these modifiers apply to intensity channels? Colour temp is built
from
> multiple raw sensors I believe (like illuminance is often done?) Hence
it's another
> 'virtual' channel we compute?
Yes.
At channel 0 - correct?

So we now have illuminance0_input and in_cct0 - correct?

Clear uses chan 0 and as before, chan 1 - so as before intensityN_raw
mapped to both - correct?

Red is channel 1 - so we have in_intensity1_red_raw - correct?

Green = intensity2_green_raw.. and so on correct?
> >
> > The 'clear' and IR channels are already covered by the use of
> > IIO_LIGHT and IIO ILLUMINANCE (and respective modifiers).
> > The RGB modifiers will help to express the relative frequencies to
> > their respective channel, and appear to fit well with the overall
convention.
> >
> > And last but not least, the textual modifier names "red", "green",
and
> > "blue" be accommodated within 'industrialio-core'.
> Fine with me.
>

Proximity remains at channel 0 correct?


> >
> > Channel specific interrupt event / sources are not presented at this
> > time.
> >
> > Any thoughts or comments are welcomed.
> >
> > Jon Brenner
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-iio"
> > in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo
> > info at http://vger.kernel.org/majordomo-info.html

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/