On 10/24/2011 04:25 PM, Jonathan Cameron wrote: > On 10/24/11 14:47, Lars-Peter Clausen wrote: >> Hi, >> >> Some chips generate events which don't really map to a channel, but are >> rather chip global. For example over-temperature events. > That one is a channel. >> Do you think this is something we should add support for or should we rather >> use a dummy channel, which doesn't report any actual values, for propagating >> the event? > Yup, have a temp channel for that one. Conceptually you might have two chips > that are otherwise identical but one has a readable temp channel, the other > doesn't. Userspace that is interested only in events won't care about > this difference. Also we want to report what the conditions are as if it were > a channel we could read. We want to know at what temperature this occurs. Ok, what should a read on such a channel return, an error value or just an dummy value? > [...] >> >> My idea for supporting channel-less events is to add a event_mask to struct >> iio_info, which would be used just like a channels event_mask, but there >> would be no index for the sysfs attributes and for events we would set the >> event number to 0xffff. > Could you give more examples? The temp one to my mind definitely needs a > channel, perhaps others do not? I am not against in principal but not > yet certain exactly when this would make sense... over-temperature is the only one i've seen so far. but other could be under-current or voltage for the whole chip. Thanks - Lars -- 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
