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Message-ID: <dea0a69e-7c5d-07ad-48da-71d19a7f75e0@quicinc.com>
Date:   Thu, 22 Jun 2023 17:51:51 -0700
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Subject: Re: [PATCH v3 21/28] ASoC: dt-bindings: Update example for enabling
 USB offload on SM8250
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To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        <srinivas.kandagatla@linaro.org>, <mathias.nyman@intel.com>,
        <perex@perex.cz>, <broonie@kernel.org>, <lgirdwood@gmail.com>,
        <krzysztof.kozlowski+dt@linaro.org>, <agross@kernel.org>,
        <Thinh.Nguyen@synopsys.com>, <bgoswami@quicinc.com>,
        <andersson@kernel.org>, <robh+dt@kernel.org>,
        <gregkh@linuxfoundation.org>, <tiwai@suse.com>
CC:     <linux-kernel@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <alsa-devel@alsa-project.org>, <devicetree@vger.kernel.org>,
        <linux-usb@vger.kernel.org>, <quic_jackp@quicinc.com>,
        <quic_plai@quicinc.com>
References: <20230308235751.495-1-quic_wcheng@quicinc.com>
 <20230308235751.495-22-quic_wcheng@quicinc.com>
 <87f20b22-6305-7590-1dbf-014b5898b15c@linaro.org>
From:   Wesley Cheng <quic_wcheng@quicinc.com>
In-Reply-To: <87f20b22-6305-7590-1dbf-014b5898b15c@linaro.org>
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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
>