Re: [PATCH] ASoC: cpcap: Implement set_tdm_slot for voice call support

[Tony Lindgren <tony@atomide.com>]

* Mark Brown <broonie@kernel.org> [200218 17:43]:
> On Tue, Feb 18, 2020 at 06:06:28PM +0100, Sebastian Reichel wrote:
> 
> > simple-graph-card is the current machine driver. We might have to
> > introduce a Droid 4 specific driver instead. I used simple(-graph)-card
> > instead of introducing a new driver, since the setup was simple enough
> > without modem and bluetooth. The simple card was perfect to test the CPCAP
> > codec driver. The TDM things might be complex enough to create
> > a new machine driver (as I mentioned in the original patchset
> > adding CPCAP codec support).
> 
> I tend to agree here, phones are generally one of the most complicated
> classes of system for clocking and interconnects and the CODECs they use
> often the most complex too so they're really stretching the generic
> cards.  It'd be nice to be able to handle things with generic cards but
> it's likely you'll run into issues that it'd be unreasonable to force
> you to address for system enablement.  OTOH if you manage to get one of
> the generic cards working well that'd be excellent!

Well to me it seems that we just already have all the data needed with
the graph binding and snd-soc-audio-graph-card + codec2codec support.

I don't think we have cases where the cpcap codec is not the master,
so as long as the cpcap codec knows what's going on then there
may not be a need for machine driver.

I guess the the bluetooth to modem path is the one to check to see
what provides the clocks..

Regards,

Tony