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Date: Mon, 1 Dec 2008 19:41:36 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Jonathan Cameron <jic23@cam.ac.uk>
Cc: LKML <linux-kernel@vger.kernel.org>, Dmitry Torokhov <dtor@mail.ru>,
       David Brownell <david-b@pacbell.net>, Jean Delvare <khali@linux-fr.org>,
       Ben Nizette <bn@niasdigital.com>, Jonathan Cameron <jic23@cam.ac.uk>,
       LM Sensors <lm-sensors@lm-sensors.org>,
       spi-devel-general@lists.sourceforge.net
Subject: Re: [Industrial I/O] [0/13] RFC: IIO v3 patchset
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> have both functions. The sort of devices we are talking typically
> communicate over I2C or SPI buses though drivers for rs232 devices etc are
> definitely on the cards. Basically we are interested in devices where direct
> memory mapped access is not possible.

We have I2C and SPI drivers so I assume you will use the lower layers of
the stacks to do this ?

> For discussion of why these don't fit within existing subsystems see 
> http://lkml.org/lkml/2008/5/20/135 and the rest of the associated thread.

I don't see much there which says why you can't unify all this in a user
space library.

For RS232/423/.. devices you can go this path if you want (but I would
keep it all in userspace anyway) as you can use a line discipline to sit
on top of the port and provide another interface (eg the way PPP does)