[PATCH 4/4] ASoC: wm8904: add DMIC support

[Pierluigi Passaro]

> > Just for my understanding, are you suggesting to set a device tree
> > property to force a fixed behavior in the driver ?

> Yes.

Why should we use a fixed behavior ?

> > WM8904 allows using both a DMIC and LINEIN, switching between one or
> > the other and this is how we currently use it.
> > Why the user should not be allowed to switch between DMIC and LINEIN ?

> The device shares pins between the line inputs and the DMIC inputs so at
> least some of the configuration is going to be determinted at system
> design time, that will fix the usable values of at least one of the
> controls which ought to be reflected in the runtime behaviour.

In our design we use:
- pin 1: DMIC_CLK
- pin 24: LINEIN2R
- pin 26: LINEIN2L
- pin 27: DMIC_DATA
we have no pins shared among DMIC and LINEIN.
We have several customer switching between DMIC and LINEIN at runtime.

> Please fix your mail client to word wrap within paragraphs at something
> substantially less than 80 columns.  Doing this makes your messages much
> easier to read and reply to.

I beg your pardon: it should be fixed now.