From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:37884 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751000AbbDVU6s (ORCPT ); Wed, 22 Apr 2015 16:58:48 -0400 Message-ID: <55380B86.6090404@kernel.org> Date: Wed, 22 Apr 2015 21:58:46 +0100 From: Jonathan Cameron MIME-Version: 1.0 To: Lars-Peter Clausen , sathyanarayanan.kuppuswamy@linux.intel.com, Daniel Baluta CC: Peter Meerwald , "linux-iio@vger.kernel.org" , Srinivas Pandruvada Subject: Re: [PATCH v1 2/3] iio: ltr501: Add interrupt rate control support References: <212b45fac712e84a3cf0bc5955def7d1b683a6bd.1427856701.git.sathyanarayanan.kuppuswamy@linux.intel.com> <551C030E.1090309@metafoo.de> <551C0B95.9080802@metafoo.de> <551C2EC4.1050208@linux.intel.com> <551C2F63.50609@metafoo.de> <551C41C0.2050609@linux.intel.com> <551C4562.9030607@linux.intel.com> <55265195.9080100@kernel.org> <5526FE97.8070705@linux.intel.com> <5537C565.4000704@metafoo.de> In-Reply-To: <5537C565.4000704@metafoo.de> Content-Type: text/plain; charset=utf-8 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.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 > > -- > 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