[PATCH 4/4] dt-bindings: sound: intel,keembay-i2s: Add channel-max property

[Sit, Michael Wei Hong]

> -----Original Message-----
> From: Mark Brown <broonie at kernel.org>
> Sent: Monday, 3 August, 2020 6:49 PM
> To: Sit, Michael Wei Hong <michael.wei.hong.sit at intel.com>
> Cc: alsa-devel at alsa-project.org; tiwai at suse.com; pierre-
> louis.bossart at linux.intel.com; Rojewski, Cezary
> <cezary.rojewski at intel.com>; Shevchenko, Andriy
> <andriy.shevchenko at intel.com>; liam.r.girdwood at linux.intel.com;
> Sia, Jee Heng <jee.heng.sia at intel.com>
> Subject: Re: [PATCH 4/4] dt-bindings: sound: intel,keembay-i2s: Add
> channel-max property
> 
> On Mon, Aug 03, 2020 at 01:59:10AM +0000, Sit, Michael Wei Hong
> wrote:
> > > On Thu, Jul 30, 2020 at 01:53:19PM +0800, Michael Sit Wei Hong
> wrote:
> 
> > > > Add a property that configures the interface to the desired max
> > > > number of capture channels. The platform may have multiple
> > > > interfaces with different number of capture channels.
> 
> > > Why?  None of the other platforms which support many
> channels need
> > > this defining and the constraint code and/or machine driver
> would
> > > normally be where this would be handled.
> 
> > The platform uses the audio-graph-card to create the dai-links,
> and doesn't use a specific machine driver code.
> 
> The audio-graph-card is very flexible and if it doesn't support
> something which it is useful to configure per platform then that's
> the place to add the extension, not some DAI specific driver.
> 
> > The platform also has 2 different interfaces which have different
> supported max-channels.
> > Using this value in the device-tree to determine the maximum
> supported channel of the interface.
> 
> These should have different compatible strings, there are likely
> further differences between them (even if they are not currently
> documented).
> 
The 2 different I2S ports are from the same SoC which supports different
number of channels, do we need different compatible strings for this?
Considering the only difference is the maximum supported channels is 8 and 2?

> Please fix your mail client to word wrap within paragraphs at
> something substantially less than 80 columns.  Doing this makes
> your messages much easier to read and reply to.