Multi-bit access
fpagliughi opened this issue · 4 comments
Hi! Do you have a plan, in the near future, to implement the access of multiple bits simultaneously? If not, do you want me to take a crack at it? I'm going to need this within the next few weeks.
Turns out the initial need was mainly to be able to add individual input bit monitoring to an app that was already using poll() for a number of other non-GPIO file handles. This was solved pretty easily with #4
I hadn't seen it documented, but apparently the line event handle can also be used to read the current value of the bit. So it would be great to add a get_value(&self) to the LineEventHandle implementation.
And, finally, the actual multi-bit access might be implemented with a Lines (plural) struct. It would mimic the Line struct, but take a slice/array/Vec of offsets and values for each call where the Line struct only takes or returns a single value.
Down the road adding support for handles/events over multiple lines will definitely be desired. It doesn't fit a lot of use cases as all the lines need to be configured the same way (this is a limitation of the kernel) but does have some nice performance benefits in some specific cases so it is something we'll want to do eventually.
Probably once #8 lands the next focus will be getting a release out and seeing about moving things to the rust-embedded org and getting feedback on ergonomics so we can get any breaking changes in early.
That sounds great. I've made some progress on the multi-line stuff, and might have something as early as next week. But I agree that we shouldn't hold up what we have already for a release. The multi-line stuff can come in later as v0.2 or beyond.
Done in PR #10.