On Mon, Oct 23, 2023, at 15:30, Balas, Eliza wrote: >> -----Original Message----- >> Cvetic <dragan.cvetic@xxxxxxx>; Arnd Bergmann <arnd@xxxxxxxx> >> Subject: Re: [PATCH v3 2/2] drivers: misc: adi-axi-tdd: Add TDD engine >> > > > Since the device is not an iio device, using an iio function would be confusing. >> > > >> > > Why isn't this an iio device? >> > >> > The device is not registered into the IIO device tree, >> > and does not rely on IIO kernel APIs. >> > Even though there are a few attributes that resemble the >> > ones from iio, and the sysfs structure is similar, >> > this is not an IIO device. >> > In the previous patch versions 1 and 2 we concluded >> > that this device fits better in the misc subsystem. >> >> Ok, can you point to that in the changelog where the IIO maintainer >> agreed that this doesn't fit into that subsystem? >> > This was one of the discussions from previous v2 : > https://lore.kernel.org/all/5b6318f16799e6e2575fe541e83e42e0afebe6cf.camel@xxxxxxxxx/ > > I will add it to the changelog the next time I submit the patches. It sounds like Jonathan wasn't quite sure either here, and I would still argue (as I did in that thread), that drivers/iio is probably a better option than drivers/misc. In particular, you mention that you actually make this device appear as an IIO device to user space using the "iio-fake" hack. I can see that IIO is not a perfect fit if this is the only device of its kind, but going that way anyway avoids a number of problems by reusing infrastructure for the IIO ABI and serialization with in-kernel users, as well as giving you the option of adding other compatible drivers later. Arnd
