new: Support for linux Industrial I/O (iio)

[ubergesundheit]

Do you plan to add support for interfacing with devices through the Industrial I/O linux subsystem? It features many device drivers already baked into the linux kernel (see here for a list).

I would very much like the idea of using go for reading values from sensors connected through iio.

[maruel]

I wasn't aware so there's no plan. :) If RPi's can get recent drivers (as many seem to have been touched in the past year), it would be interesting.

I looked on a RPi3, ODROID and x64 host running Ubuntu 16.04 and failed to see /sys/bus/iio, as documented athttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/ABI/testing/sysfs-bus-iio. It seems like a device tree overlay is needed, which is non-trivial for users.

If this ever to work out, the plan would be to create a package periph.io/x/periph/host/iio, have it query with whatever interface and populate what is available here.

[ubergesundheit]

Thank you for your answer. You are right that the interface is not easily enabled. On rasperry pi devices one must configure the dtoverlays in the /boot/config.txt file to enable the devices.

Do you have any tips for implementing the periph.io/x/periph/host/iiopackage? Would it use host/fs?

[maruel]

host/fs exists to enable unit testing so it's a good idea to use it for this reason, but it's not an hard requirement.

You could start in experimental/host/iio and start to work iteratively from there, and then once it's deemed stable enough we can move it back as host/iio. So if you want to commit to implement at least code to have a functional baseline, I'm fine with you start contributing into experimental. You may also want to do an initial prototype on a private branch if you want, just to weed out the very initial key design elements. It may be challenging to design especially as I think you may need to create a "registry of devices found". It's as you prefer.

As part of this task, another important point will be to document how to enable it on https://github.com/periph/website, not sure where exactly yet.

Note that this code could live in a separate repository just fine too. Periph is intentionally designed to allow that. It depends on how much velocity you want to have when pushing code.

[maruel]

Ported to periph/host#45.