On Sun, 10 Sep 2017 16:00:35 +0200 Martin Kepplinger <martink@xxxxxxxxx> wrote: > Am 10. September 2017 15:44:24 MESZ schrieb Jonathan Cameron <jic23@xxxxxxxxxx>: > >On Mon, 4 Sep 2017 23:06:37 -0400 > >harinath Nampally <harinath922@xxxxxxxxx> wrote: > > > >> > I agree with your understanding. It's a rising threshold, just > >that the input > >> > will only reflect high frequency changes in the signal. > >> Thank you for the clarification. I am hoping this gets merged in the > >> next window if no other issues. > > > >There is still the open question to Martin on what he meant in his > >review to be addressed. > > > >Martin, any comments on this? > > > >I'm really looking for an OK from Martin before I take this one. > >Plenty of time though given the merge window is still open! > > I had a look at v6 of this. > doh. I hadn't registered there was a v6! > > > >I'm travelling this week so response may be a bit random depending > >on conference wifi and how interesting the material is ;) > > enjoy, Thanks ;) > > martin > > > > >Jonathan > > > >> > >> Thanks, > >> Hari > >> > >> On Sun, Sep 3, 2017 at 12:24 PM, Jonathan Cameron <jic23@xxxxxxxxxx> > >wrote: > >> > On Tue, 29 Aug 2017 23:01:16 -0400 > >> > harinath Nampally <harinath922@xxxxxxxxx> wrote: > >> > > >> >> > We should never say "transient is for rising > >> >> > direction" or "ff_mt is for falling direction". any combination > >is fine. > >> >> > >> >> Ok I agree that there is no hard and fast rule that "transient is > >for rising > >> >> direction" or "ff_mt is for falling direction". > >> >> But in our case, datasheet for these chips define these events > >based on > >> >> acceleration magnitude rising or falling below a set threshold > >value. > >> >> > >> >> For quick reference, below excerpts are from fxls8471 datasheet: > >> >> Motion Event: "When the acceleration exceeds a set threshold for a > >set > >> >> amount of time, > >> >> the motion interrupt is asserted." > >> >> > >> >> Freefall event: "The detection of “Freefall” involves the > >monitoring > >> >> of the X, Y, and Z axes > >> >> for the condition where the acceleration magnitude is below a > >> >> user-specified threshold > >> >> for a user-definable amount of time" > >> >> > >> >> Transient event: "When the high-pass filter is bypassed, the > >> >> functionality becomes > >> >> similar to the motion-detection function; in this mode, > >acceleration > >> >> greater than > >> >> a programmable threshold is detected (along an axis)." > >> >> > >> >> Therefore I think in this driver freefall event is defined as > >> >> 'falling' event type and > >> >> motion event is defined as 'rising' event type and Transient is > >also defined as > >> >> 'rising' event type. > >> >> As you might already know that mma8562 and mma8563 doesn't have > >> >> transient event support > >> >> but they do have freefall and motion event support which are > >defined > >> >> as 'fall' and 'rise' > >> >> event types respectively. Please note in this driver, motion event > >is > >> >> enabled/configured only > >> >> for mma8652 and mma8653. > >> >> Therefore if I read/write sysfs node for 'rise' it should use the > >> >> FF_MT registers for mma8652 and mma853, but for all others like > >> >> mma8451, mma8452 and > >> >> mma8453 which has transient event support it picks the Transient > >> >> registers if enabled. Also please > >> >> note transient event is enabled(but not motion event) for mma8451, > >> >> mma8452 and mma8453. > >> >> The problem seems like we have two different events(motion and > >> >> transient) that are defined > >> >> as same event type 'rising' but in fact both motion and transient > >are > >> >> pretty much similar as they > >> >> both raise interrupt flag when the acceleration magnitude rises > >above > >> >> the threshold. > >> >> Only difference is transient event has its own event config > >registers > >> >> with High pass filter. > >> >> If HPF bypassed using config register transient event acts like > >motion > >> >> detection event. > >> > > >> >> > >> >> That was my understanding but please correct me if I am wrong. > >> > > >> > I agree with your understanding. It's a rising threshold, just > >that the input > >> > will only reflect high frequency changes in the signal. > >> > > >> >> > >> >> > Only freefall mode needs one fix: remembering to which set of > >registers to fall back when > >> >> > disabling it. > >> >> > >> >> I don't quite understand what you mean by 'to fall back when > >disabling > >> >> it'. Please elaborate. I would > >> >> appreciate if you could suggest your logic in the form of > >pseudo-code. > >> >> Thanks for your time > >> >> > >> > ... > -- 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
