Re: [PATCH] ASoC - Add support for upto 16 channels on OMAP MCBSP

[Liam Girdwood <lrg@slimlogic.co.uk>]

On Fri, 2009-11-06 at 13:20 +0000, Mark Brown wrote:
> On Thu, Nov 05, 2009 at 08:08:30PM +0000, Liam Girdwood wrote:
> > On Thu, 2009-11-05 at 21:28 +0200, Jarkko Nikula wrote:
> 
> > > Would be nice if both the divider and frame size are calculated
> > > dynamically based on CLKSRG frequency and sample rate.
> 
> > This does sound like a useful feature and should probably exist in
> > soc-core for other platforms too.
> 
> A lot of drivers would probably have trouble using this due to the
> number of different constraints in the dividers that can be set up that
> random hardware has - it'd probably take more effort to finesse things
> than it's worth - but a utility function for mostly unconstrained
> hardware would be good.

I was thinking more generic here. e.g. additions to soc.h :-

static inline int snd_soc_get_framesize(int clock, struct snd_pcm_hw_params *params);

A caller could vary clock based upon it's divider options. Error would
be returned if there was not enough bandwidth.

and

static inline int snd_soc_get_divider(int clock, struct snd_pcm_hw_params *params);

This would return the integer divider required or bandwidth error.

and

static inline int snd_soc_get_min_clock(struct snd_pcm_hw_params *params);

return min bit clock required for params.

Liam