Re: [PATCH] ASoC: fsl-asoc-card: add wm8960 support

[Shawn Guo <shawnguo@kernel.org>]

On Fri, Aug 14, 2015 at 02:22:53AM -0700, Nicolin Chen wrote:
> I have to add Shawn for help :)
> 
> On Fri, Aug 14, 2015 at 03:38:16PM +0800, Zidan Wang wrote:
> 
> > ccm ----->1------------------>2<------------>3
> > 	  |                   |
> >     	  |                   |		
> > 	  4 SAIx MCLK1        5 SAIx MCLK2
> > 
> > If this bit is set, the clock route is ccm->1->2->3, 2 to 5 is disconnect.
> > If this bit is clear, the clock route is 3->2->5, 1 to 2 is disconnect.
> 
> @Shawn
> 
> Suppose 1 and 2 are clock MUXs that we can't specifically touch
> via registers. And 3 is an IO PAD that can either output a clock
> from CCM or input a clock from an external source outside SoC.
> Both 4 and 5 are two clock sources for one single SAI, SAI2 for
> example.
> 
> There is a bit in the GPR register to control above routes. And
> my question is where should be the best place to put this bit.

If this route selection is a decision of board design, it should fit
device tree quite well.  As the platform maintainer, I surely hope we
can handle this in audio driver.  But if there is really no place better
than platform code to handle it, I can accept it.

Shawn

> 
> Apparently it's outside the CCM and SAI, not to mention it is
> hard to relate this bit to this ASoC dai-link driver which's
> supposed to solve problems between the SAI and CODECs.
> 
> Thanks
> Nicolin