[alsa-devel] [PATCH] ASoC: fsl_sai: Implement set_bclk_ratio

[Daniel Baluta]

On Wed, Sep 11, 2019 at 2:01 PM Mark Brown <broonie at kernel.org> wrote:
>
> On Thu, Sep 05, 2019 at 06:29:39PM -0700, Nicolin Chen wrote:
> > On Sat, Aug 31, 2019 at 12:59:10AM +0300, Daniel Baluta wrote:
>
> > > This is to allow machine drivers to set a certain bitclk rate
> > > which might not be exactly rate * frame size.
>
> > Just a quick thought of mine: slot_width and slots could be
> > set via set_dai_tdm_slot() actually, while set_bclk_ratio()
> > would override that one with your change. I'm not sure which
> > one could be more important...so would you mind elaborating
> > your use case?
>
> The reason we have both operations is partly that some hardware
> can configure the ratio but not do TDM and partly that setting
> TDM slots forces us to configure the slot size depending on the
> current stream configuration while just setting the ratio means
> we can just fix the configuration once.  I'd say it's just a user
> error to try to do both simultaneously.

Yes, exactly. We wanted to have a better control of bclk freq.
Sorry for the late answer, I'm traveling.