Audio codec device tree entries

[Grant Likely]

On 10/24/07, Timur Tabi <timur at freescale.com> wrote:
> Jon Smirl wrote:
>
> > I see your point about putting the child node onto the control bus.
> > ac97 is both a control and data bus. For the i2s case the child should
> > go onto the i2c bus.
>
> I know AC97 is *also* a control bus, but treating I2S and AC97 differently is
> bad, IMHO.  If you're going to put the child node in the AC97 node, you should
> also put it in the I2S node.

They *are* different.  The choice you're making is whether or not you
keep them similar in the control path or the data path; but you still
have to choose.

>
> The 8610 has an SSI that can operate as either AC97 or I2S.  If I want to switch
> from AC97 to I2S, I should not have to move the child node out of the AC97 node.
>   I should instead just add an I2C node and point to it.

But you need a different codec node regardless.  The board/system will
in the vast majority of cases designed to only use AC97 or only use
I2S.  It's not moving a node.  It's deleting an ac97 codec node and
adding an i2s codec node.

Besides; correctness is more important that how many device tree
changes need to be made to go from one board design to another.

Cheers,
g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
grant.likely at secretlab.ca
(403) 399-0195