Re: [PATCH v1 2/3] iio: ltr501: Add interrupt rate control support

[Jonathan Cameron <jic23@kernel.org>]

On 22/04/15 16:59, Lars-Peter Clausen wrote:
> On 04/10/2015 07:51 AM, Jonathan Cameron wrote:
> [...]
>>>> So level rather than edge triggered.  Definitely what we put _period
>>>> in for in the first place.  Admittedly persistence might have been a
>>> better
>>>> name, but too late now! (dratted ABI compatibility)
>>>>
>>>> J
>>> But we cannot use period for this use case. According to _period ABI
>>> description,
>>> It specifies the period of time for which the condition must be true
>>> for
>>> getting a
>>> valid event. But here, we are checking for number of times a condition
>>> must be
>>> true for generating a valid event.
>> But we are checking that condition at a known sampling rate I assume?
>> Hence
>> period = persistence x 1/sampling frequency?
> 
> Sorry for highjacking this thread.
> 
> So period is for the time interval it has the event has to be asserted before it is registered. What would we call the same thing but for the de-assertion of the event? The event has to be de-asserted for X amount of time before it gets propagated.

Err, offperiod?  resetperiod? space? (on the basis of mark-space description of square waves?)

It's kind of temporal hysteresis, or a debounce filter I suppose.  Period
isn't great for the existing interface.
> 
> Thanks,
> - Lars
> 
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