On Thu, Oct 24, 2013 at 06:17:59PM +0100, Mark Rutland wrote:
> On Fri, Oct 04, 2013 at 01:04:41AM +0100, Kuninori Morimoto wrote:

> > +- simple-audio,card-name           : simple-audio card name

> What's this used for?

This serves two useful functions.  One is that this is used for display
to users so they have a friendly name for the sound card (it is
relatively common to have multiple sound cards in the system).  The
other is that it is essentially a compatibility string for configuration
- you get a lot of sound devices that are electrically identical and
hence look the same from a driver point of view but due different
physical form factors should be configured differently.

> > +- format                           : specific format if needed, see below
> > +- frame-master                             : frame master
> > +- bitclock-master                  : bitclock master
> > +- bitclock-inversion                       : clock inversion
> > +- frame-inversion                  : frame inversion

> What do these mean? Repeating the name without a dash is completely unhelpful.
> Describe what these imply.

These are all boolean propeties.  The meanings should be obvious or at
least very easily discoverable to anyone with any familiarity with audio
hardware; if you can understand what to do with them they should be OK.

> > +- clocks                           : phandle for system clock rate

> Just one clock?

This is a limitation from the simple card, anything that needs more
complex clocking should be using a different binding.

> > +- system-clock-frequency           : system clock rate
> > +                                     it will overwrite clocks's rate

> This seems very odd.

> Why do you want to overwrite a clock's rate?

It's relatively common to derive the audio clock from a general purpose
programmable clock which needs to be configured appropriately for use.

> > +simple-audio,format
> > +   "i2s"
> > +   "right_j"
> > +   "left_j"
> > +   "dsp_a"
> > +   "dsp_b"
> > +   "ac97"
> > +   "pdm"
> > +   "msb"
> > +   "lsb"

> What do these mean? Why are they not described when the property was defined 
> above?

This is another one where the names should be clear for people familiar
with the hardware, they're well known terms.

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