Re: Ideas about an analog-to-digital converter API

[Ken Hornstein <kenh%cmf.nrl.navy.mil@localhost>]

>On Wed, Dec 31, 2008 at 06:16:28PM -0500, Ken Hornstein wrote:
>> I've been thinking about writing a driver for the A/D converter hardware
>> in one of the ARM boxes that I have.  I have the documentation, and writing
>> that driver looks relatively straightforward.  But ... what I am having
>> a problem with is: what should the userspace API look like?
>
>audio(4) may do.

You know, I should have said something about that ...

Yes, I know that an audio recorder is an A/D converter.  And I did look
at the audio interface.  But ... it's not a good fit, for a couple of
reasons:

- audio(4) is complicated.  It has a lot of stuff in it.  This complexity
  makes it a lot of work to do what I would think are relatively simple
  A/D operations.
- It doesn't have the functionality to support the features of some A/D
  converter hardware.  E.g, there isn't a way to select the analog input
  range.  You could overload some stuff in the current audio interface,
  but it just ... feels awkward.

--Ken