On 13/07/15 18:29, Matt Ranostay wrote: > On Sat, Jul 11, 2015 at 10:58 AM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote: >> On 09/07/15 18:23, Matt Ranostay wrote: >>> Hello Jonathan, >>> >>> I am currently working on temperature sensor that has multiple trip >>> points, and was wondering what would be the correct way to tie this to >>> one channel if several events may have the same IIO_EV_DIR_* >>> direction. >>> >>> low temp trippoint - > IIO_EV_DIR_FALLING >>> high temp trippoint -> IIO_EV_DIR_RISING >>> critical temp trippoint -> ? >>> >>> Would it make sensor to add functionality to allow iio_event_spec to >>> have an .index field so multiple IIO_EV_DIR_RISING could be parsed >>> into sysfs entries? >>> >>> >>> Thanks, >>> >>> Matt >>> >> Hi Matt, >> >> The few times this has come up before, the conclusion has been that >> the device was actually more suited to have a hwmon driver than an IIO one. >> We have had event units capable of being configured for this sort of operation >> but have never actually implemented it. > > Ok seems I could just mask that threshold since it is kinda redundant > and would be more useful for a microcontroller using it. > > However the other issue is there is a way of marking when entering a > threshold and when exiting it.. I suppose that is again and event code > change... This device triggers an interrupt when it enters and exits a > threshold, and it would seem wrong to poll and report threshold events > till it exited... > > I suppose the following would be too crude to add the ABI? Normally threshold interrupts are assumed to be edge triggered, hence report a rising edge in one direction and a falling one in the other? Though then we are back to having multiple thresholds on a channel. Looks increasingly like we need to add support for this! (increased cc list to get some more opinions on this). > > IIO_EV_ENTER_THRESHOLD = 0, > IIO_EV_EXIT_THRESHOLD, > >> >> You are quite correct in that we don't have a current way to support >> it. An index field and appropriate extension of the abi is fine. However >> you've also got to find somewhere in the event code to place it. >> That's nastier from an ABI change point of view. >> > -- > 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 > -- 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
