Re: [PATCH 1/3] ASoC: dt-bindings: mediatek: mt8192: Add i2s-share properties

[Jiaxin Yu <jiaxin.yu@mediatek.com>]

On Wed, 2022-05-04 at 15:38 -0500, Rob Herring wrote:
> On Fri, Apr 29, 2022 at 04:30:37PM -0400, Nícolas F. R. A. Prado
> wrote:
> > The Mediatek AFE PCM controller for MT8192 allows sharing of an I2S
> > bus
> > between two busses. Add a pattern for these properties in the
> > dt-binding.
> > 
> > Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
> > 
> > ---
> > 
> >  Documentation/devicetree/bindings/sound/mt8192-afe-pcm.yaml | 5
> > +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/sound/mt8192-afe-
> > pcm.yaml b/Documentation/devicetree/bindings/sound/mt8192-afe-
> > pcm.yaml
> > index 7a25bc9b8060..5b03c8dbf318 100644
> > --- a/Documentation/devicetree/bindings/sound/mt8192-afe-pcm.yaml
> > +++ b/Documentation/devicetree/bindings/sound/mt8192-afe-pcm.yaml
> > @@ -54,6 +54,11 @@ properties:
> >        - const: aud_infra_clk
> >        - const: aud_infra_26m_clk
> >  
> > +patternProperties:
> > +  "^i2s[0-35-9]-share$":
> > +    description: Name of the I2S bus that is shared with this bus
> > +    pattern: "^I2S[0-35-9]$"
> 
> Why not a phandle to the the other bus? That would be the DT way to
> do 
> it. But I'm not sure I really understand who is sharing what here.
> 
I can explain the usage of this property. The I2S interface of MT8192
only have 3 pins [bit clock/ frame clock/ data in(or out)]. So if we
want use them as normal I2S that has 4 pins [bit clock/ frame clock/
data in/ data out], we need to combine two MT8192 I2S interface to use.
But we need to specify whose clock they use. E.g. "i2s9-share =
"I2S8"".

> > +
> >  required:
> >    - compatible
> >    - interrupts
> > -- 
> > 2.36.0
> > 
> >