Re: [PATCH 12/14] staging: iio: adc: new driver for ADT7408 temperature sensors

[Guenter Roeck <guenter.roeck@ericsson.com>]

On Mon, Oct 25, 2010 at 07:43:12AM -0400, Jonathan Cameron wrote:
[ ... ]

> > I did not refer to the chips with generic ADC sensors.
> > The chips I referred to are AD7414/15, ADT75, ADT7310, ADT7408, and ADT7410,
> > though I may have missed some.
> You clearly got further through the set than I have so far! (I'd only come across
> the first 2 of those)  Agreed, all of these appear to be temperature only and at
> a quick look they are typically slow and low resolution so that set definitely
> want to be in hwmon.
> 
> For those parts with actual hwmon drivers, ad7414/15 and adt7408 (based on a quick
> grep unless Guenter has others queued). Lets drop them for now from the merge.
> 

Nothing queued here. Not that I would mind doing the driver conversions for ADT7310
and ADT7410 if needed, but I would need HW (eval boards) for testing.

> For the others lets put a todo in place to convert them to hwmon.  Nothing wrong
> with putting them in staging (under IIO or otherwise) in the meantime as far
> as I am concerned.
> 
> > 
> >> We went through this in a lot of depth back when IIO first came about.
> >> There is a boundary. We just need to pin down where it is.
> > 
> > For the ambient temperature sensors on the other chips - did you consider
> > adding hwmon device entries for those ? There may of course be reasons against
> > doing that, but it may be an option. There are other drivers outside the hwmon 
> > directory which call hwmon_device_register(), so it is not a new concept.
> It depends on whether they are generally useful for temperature monitoring.
> On the whole they are giving one the value on a particular bit of silicon
> in the chip (not the ambient temperature near by). They aren't reading it for
> monitoring purposes, but because it is needed to calibrate the other sensors in
> the package.  We even have devices with multiple temperature sensors, one on
> each MEMs device. Also they often get read into a buffer with all the rest
> of the channels.
> 
> Lets leave the decision on this up to individual driver writers.  If they are using
> the device to do hwmon stuff as well as whatever else it is for then we encourage them
> to register it with hwmon as you suggest.
> 
Ok, makes sense.

Thanks,
Guenter