Re: [PATCH 3/3] iio: wrapper: unit-converter: new driver

From: Peter Rosin
Date: Tue Mar 27 2018 - 09:32:28 EST


On 2018-03-27 15:22, Jonathan Cameron wrote:
> On Tue, 27 Mar 2018 09:42:40 +0200
> Peter Rosin <peda@xxxxxxxxxx> wrote:
>> On 2018-03-24 15:03, Jonathan Cameron wrote:
>>> On Mon, 19 Mar 2018 18:02:46 +0100
>>> Peter Rosin <peda@xxxxxxxxxx> wrote:
>>>> + if (iio_channel_has_info(pchan, IIO_CHAN_INFO_RAW))
>>>> + chan->info_mask_separate |= BIT(IIO_CHAN_INFO_RAW);
>>> if the parent doesn't support RAW, is there a lot of point in carrying on?
>>
>> Nope, better to error out I suppose. But I'm not familiar with channels
>> without RAW, what alternatives are there anyway?
>
> Potentially _PROCESSED though that will need somewhat different handling.
> A nasty trick for that might be to map it to RAW and then have the SCALE
> reflect the divider circuit scale only.

Hmm, I think a lot of things might assume RAW to be a pure integer, and
maybe they are even correct to do so? So yes, that seems nasty indeed...

> It's perfectly possible to have channels with neither _RAW or _PROCESSED
> but I suspect we don't care about them here.
>
> There might be an application that needs to do buffered data flows in the
> long run, but we can figure out how to do that when one exists.
>
> It won't be a huge amount more than you have here, though we might need
> a trigger pass through as well to allow you to set the trigger for
> the front end and having it automatically applied to the backend.

Yes, this is the same for the iio-mux. I don't need it, I in fact need
very little bandwidth for these things. Someone with an itch will have
to fill in the buffer/trigger handling...

Cheers,
Peter