Add an example on enabling of USB offload for the Q6DSP.  The routing can
be done by the mixer, which can pass the multimedia stream to the USB
backend.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 .../devicetree/bindings/sound/qcom,sm8250.yaml    | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml b/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml
index 262de7a60a73..13145e010ddf 100644
--- a/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml
+++ b/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml
@@ -220,6 +220,21 @@ examples:
                 sound-dai = <&vamacro 0>;
             };
         };
+
+        usb-dai-link {
+            link-name = "USB Playback";
+            cpu {
+                sound-dai = <&q6afedai USB_RX>;
+            };
+
+            codec {
+                sound-dai = <&usbdai USB_RX>;
+            };
+
+            platform {
+                sound-dai = <&q6routing>;
+            };
+        };
     };
 
   - |

On 09/03/2023 00:57, Wesley Cheng wrote:
> Add an example on enabling of USB offload for the Q6DSP.  The routing can
> be done by the mixer, which can pass the multimedia stream to the USB
> backend.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

You still miss binding change to APR/GPR. Where is the USB DAI going to sit?



Best regards,
Krzysztof

Hi Krzysztof,

On 3/10/2023 12:56 AM, Krzysztof Kozlowski wrote:
> On 09/03/2023 00:57, Wesley Cheng wrote:
>> Add an example on enabling of USB offload for the Q6DSP.  The routing can
>> be done by the mixer, which can pass the multimedia stream to the USB
>> backend.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> 
> 
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> 
> You still miss binding change to APR/GPR. Where is the USB DAI going to sit?
> 

My initial idea is to have it as part of the q6afe APR node (as a 
child).  It would need to issues some transactions over APR to the Q6AFE 
port on the audio DSP, which was the main reason for this.

Something like:

q6afe: apr-service@4 {
	compatible = "qcom,q6afe";
	reg = <APR_SVC_AFE>;
	q6afedai: dais {
		compatible = "qcom,q6afe-dais";
		#address-cells = <1>;
		#size-cells = <0>;
		#sound-dai-cells = <1>;
	};
...
	usbdai: usbd {
		compatible = "qcom,q6usb";
		#sound-dai-cells = <1>;
		iommus = <&apps_smmu 0x180f 0x0>;
		qcom,usb-audio-stream-id = <0xf>;
		qcom,usb-audio-intr-num = <2>;
	};
};

I think the only modification I would probably make is to have an 
example of how to add the q6usb node to enable the audio offloading.

Thanks,
Wesley Cheng

> 
> 
> Best regards,
> Krzysztof
>