Re: Kernel wishlist item: Better IIO API

[Bastien Nocera <hadess@hadess.net>]

On Wed, 2014-10-29 at 18:21 +0100, Lars-Peter Clausen wrote:
> On 10/29/2014 03:30 PM, Bastien Nocera wrote:
> > Hey,
> >
> > I've posted this a couple of days ago:
> > http://www.hadess.net/2014/10/a-gnome-kernel-wishlist.html
> > along with a mail to LKML:
> > http://thread.gmane.org/gmane.linux.kernel/1810083
> >
> > I've recently added to my list an item about IIO:
> > https://wiki.gnome.org/BastienNocera/KernelWishlist
> >
> > Are there any plans for a better API for the IIO subsystem? The API
> > might be good enough to drive from shell scripts, or helpers that only
> > need to work with one variant of a device, but my attempts at trying to
> > use the IIO subsystem to provide an accelerometer to do automatic
> > display rotation[1] showed that the API is really cumbersome.
> >
> > The code I wrote spends most of its time creating sysfs paths, reading
> > values in different formats, and mangling filenames[2].
> >
> > Is an ioctl-based API planned? Something where I could get/set
> > structures to gather metadata about the device, and set it up easily, so
> > reading data from it is easier?
> 
> No, unfortunately not and I'm not sure if such a ABI would be accepted if 
> proposed.

Why not?

> But checkout libiio[1][2], it hides the details of the sysfs file manipulation.

I'm not sure that's any better unfortunately. I've certainly tried to do
that already in my code, but that doesn't change that the user-space API
is barely usable.

Cheers

> [1] https://github.com/analogdevicesinc/libiio
> [2] http://analogdevicesinc.github.io/libiio/