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

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

[Jon Brenner]

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@vger.kernel.org
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.

IIO modifiers:
IIO_MOD_LIGHT_RED
IIO_MOD_LIGHT_GREEN
IIO_MOD_LIGHT_BLUE

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'.

Channel specific interrupt event / sources are not presented at this
time.

Any thoughts or comments are welcomed.

Jon Brenner

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

[Jonathan Cameron]

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@vger.kernel.org
> 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?
>
> 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.

>
> 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@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

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

[Jon Brenner]

Replies in-line,


> -----Original Message-----
> From: Jonathan Cameron [mailto:jic23@cam.ac.uk]
> Sent: Wednesday, April 04, 2012 3:40 AM
> To: Jon Brenner
> Cc: jic23@kernel.org; gregkh@linuxfoundation.org;
linux-iio@vger.kernel.org;
> linux-kernel@vger.kernel.org
> 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@vger.kernel.org
> > 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@vger.kernel.org More majordomo
> > info at  http://vger.kernel.org/majordomo-info.html

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

[Jonathan Cameron]

Jon Brenner <jbrenner@TAOSinc.com> wrote:

>Replies in-line,
>
>
>> -----Original Message-----
>> From: Jonathan Cameron [mailto:jic23@cam.ac.uk]
>> Sent: Wednesday, April 04, 2012 3:40 AM
>> To: Jon Brenner
>> Cc: jic23@kernel.org; gregkh@linuxfoundation.org;
>linux-iio@vger.kernel.org;
>> linux-kernel@vger.kernel.org
>> 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@vger.kernel.org
>> > 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?
Yup. It is the first illuminance channel.
>
>So we now have illuminance0_input and in_cct0 - correct?
Should be in_illuminance0_input and in_cct0_input
Otherwise yes.  Maybe don't skimp on chars and have in_colourtemp_input 
>
>Clear uses chan 0 and as before, chan 1 - so as before intensityN_raw
>mapped to both - correct?
Don't necessarily need indexes if using modifiers. We don't bother for inertial sensors... event codes include modifiers so they are optional.  Channel can have index or modifier or both...
>
>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?
Yes
>
>
>> >
>> > 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@vger.kernel.org More
>majordomo
>> > info at  http://vger.kernel.org/majordomo-info.html
>
>--
>To unsubscribe from this list: send the line "unsubscribe linux-iio" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html

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