Re: [PATCH v1 1/4] ASoC: dt-bindings: qcom,q6apm-lpass-dais: Document DAI subnode

[Mohammad Rafi Shaik]

On 3/10/2026 1:25 AM, Dmitry Baryshkov wrote:
> On Mon, Mar 09, 2026 at 04:42:57PM +0530, Mohammad Rafi Shaik wrote:
> > Extend the qcom,q6apm-lpass-dais device tree binding to explicitly
> > describe Digital Audio Interface (DAI) child nodes.
> >
> > Add #address-cells and #size-cells to allow representation of multiple
> > DAI instances as child nodes, and define a dai@<id> pattern to document
> > per-DAI properties such as the interface ID and associated clocks.
>
> Is there a physical device being represented by this DAI subnode?

No, the dai@<id> subnode does not represent a separate physical device.
It models an individual LPASS/Q6DSP DAI hw interface instance (for 
example, primary mi2s, secondary mi2s, etc.), so that per‑DAI resources 
and configuration can be described.

Per‑port description is required because different DAIs may need 
different clock inputs (MCLK, BCLK, ECLK) and can be wired differently 
depending on the board design. By representing each DAI instance as a 
child node, the relevant clocks can be bound to the specific DAI port 
that uses them.

Thus, the subnode is used to describe the resources and configuration of 
a DAI hw instance, not a standalone physical device.

> > Qualcomm platforms like talos integrate third-party audio codecs or use
> > different external audio paths. These designs often require additional
> > configuration such as explicit MI2S MCLK settings for audio to work.
> >
> > Co-developed-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Mohammad Rafi Shaik <mohammad.rafi.shaik@xxxxxxxxxxxxxxxx>
> > ---
> >   .../bindings/sound/qcom,q6apm-lpass-dais.yaml | 41 ++++++++++++++++++-
> >   1 file changed, 40 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/sound/qcom,q6apm-lpass-dais.yaml b/Documentation/devicetree/bindings/sound/qcom,q6apm-lpass-dais.yaml
> > index 2fb95544d..1d770cbcb 100644
> > --- a/Documentation/devicetree/bindings/sound/qcom,q6apm-lpass-dais.yaml
> > +++ b/Documentation/devicetree/bindings/sound/qcom,q6apm-lpass-dais.yaml
> > @@ -21,6 +21,34 @@ properties:
> >     '#sound-dai-cells':
> >       const: 1
> >   
> > +  '#address-cells':
> > +    const: 1
> > +
> > +  '#size-cells':
> > +    const: 0
> > +
> > +# Digital Audio Interfaces
> > +patternProperties:
> > +  '^dai@[0-9]+$':
> > +    type: object
> > +    description:
> > +      Q6DSP Digital Audio Interfaces.
> > +
> > +    properties:
> > +      reg:
> > +        description:
> > +          Digital Audio Interface ID
> > +
> > +      clocks:
> > +        minItems: 1
> > +        maxItems: 3
> > +
> > +      clock-names:
> > +        minItems: 1
> > +        maxItems: 3
> > +
> > +    additionalProperties: false
> > +
> >   required:
> >     - compatible
> >     - '#sound-dai-cells'
> > @@ -29,7 +57,18 @@ unevaluatedProperties: false
> >   
> >   examples:
> >     - |
> > -    dais {
> > +    #include <dt-bindings/sound/qcom,q6afe.h>
> > +
> > +    bedais {
> >           compatible = "qcom,q6apm-lpass-dais";
> >           #sound-dai-cells = <1>;
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        dai@16 {
>
> What is @16 in this case? What kind of address or ID correspondings to
> the PRIMARY_MI2S_RX?

yes, The @16 value corresponds to the LPASS/Q6DSP DAI ID for 
PRIMARY_MI2S_RX.

(defined in : 
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git/tree/include/dt-bindings/sound/qcom,q6dsp-lpass-ports.h)

Best Regards,
Rafi.

> > +           reg = <PRIMARY_MI2S_RX>;
> > +           clocks = <&q6prmcc LPASS_CLK_ID_MCLK_1
> > +                              LPASS_CLK_ATTRIBUTE_COUPLE_NO>;
> > +           clock-names = "mclk";
> > +        };
> >       };
> > --
> > 2.34.1