On Thu, Nov 06, 2014 at 12:02:49AM +0400, Dmitry Eremin-Solenikov wrote:

2014-11-03 16:41 GMT+03:00 Linus Walleij [off-list ref]:

quoted

The point is still the same: no unrelated code in drivers/mfd,
then either use IIO DAC as a middle layer or sink the DAC handling
into respective subdriver, i.e. push it into the backlight or
volume directly then.

The problem is that the DAC is equally used by backlight and by sound
device (WIP).
What about true i2c device driver sitting in drivers/misc and exporting a regmap
of 2 8-bit registers?

If it can just export registers that sounds like a MFD.  If it needs to
export functionality then like Linus says the IIO subsystem abstracts
DACs.