Re: [PATCH v5 23/32] ASoC: dt-bindings: Add Q6USB backend

[Wesley Cheng <quic_wcheng@quicinc.com>]

Hi Rob,

On 8/31/2023 10:29 AM, Rob Herring wrote:
> On Tue, Aug 29, 2023 at 02:06:48PM -0700, Wesley Cheng wrote:
>> Add a dt-binding to describe the definition of enabling the Q6 USB backend
>> device for audio offloading.  The node carries information, which is passed
>> along to the QC USB SND class driver counterpart.  These parameters will be
>> utilized during QMI stream enable requests.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>   .../bindings/sound/qcom,q6usb-dais.yaml       | 53 +++++++++++++++++++
> 
> filename should match the compatible.
> 

Got it.

>>   1 file changed, 53 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/sound/qcom,q6usb-dais.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/sound/qcom,q6usb-dais.yaml b/Documentation/devicetree/bindings/sound/qcom,q6usb-dais.yaml
>> new file mode 100644
>> index 000000000000..72254d7e70d2
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/sound/qcom,q6usb-dais.yaml
>> @@ -0,0 +1,53 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/sound/qcom,q6usb-dais.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Qualcomm ASoC DPCM USB backend DAI
>> +
>> +maintainers:
>> +  - Wesley Cheng <quic_wcheng@quicinc.com>
>> +
>> +description:
>> +  The USB port is a supported AFE path on the Q6 DSP.  This ASoC DPCM
>> +  backend DAI will communicate the required settings to initialize the
>> +  XHCI host controller properly for enabling the offloaded audio stream.
>> +  Parameters defined under this node will carry settings, which will be
>> +  passed along during the QMI stream enable request and configuration of
>> +  the XHCI host controller.
>> +
>> +allOf:
>> +  - $ref: dai-common.yaml#
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - qcom,q6usb
>> +
>> +  iommus:
>> +    maxItems: 1
>> +
>> +  "#sound-dai-cells":
>> +    const: 1
>> +
>> +  qcom,usb-audio-intr-num:
>> +    description:
>> +      Desired XHCI interrupter number to use.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
> 
> This is the range as num-hc-interrupters, right?
> 
> Perhaps this should also be uint16 and limited to 1024 (or 8).
> 

True, will change that accordingly.

> But why does this need to be in DT? Can't the OS just pick one to
> assign? (the description should answer this)
> 

Intention of this is because the user of the secondary interrupter ring 
is listening to a particular event ring.  For example, the audio DSP 
would only work on interrupter ring#2 for SM8350, but can possibly 
differ on other platforms.

Thanks
Wesley Cheng