Re: [PATCH 4/5] ASoC: dt-bindings: qcom: Document qcom,msm8916-qdsp6-sndcard compatible

Rob Herring
2021-12-13T20:24:36Z

On Thu, 02 Dec 2021 15:55:04 +0100, Stephan Gerhold wrote:
> There are two possible audio setups on MSM8916/APQ8016: Normally the audio
> is routed through the audio/modem DSP (covered by the qdsp6 driver). During
> upstreaming for the DragonBoard 410c it was decided to bypass it and
> instead talk directly to the audio controller using the "lpass" driver.
>
> Bypassing the DSP gives more control about the audio configuration but limits
> the functionality: For example, routing audio through the audio/modem DSP is
> strictly required for voice call audio. Also, without the special changes in
> the DB410c firmware other MSM8916 devices can only use the bypass as long as
> the modem DSP is not started. Otherwise, the firmware will assume control of
> the LPASS hardware block and audio is no longer functional.
>
> Add support for using the DSP audio setup instead using a new
> "qcom,msm8916-qdsp6-sndcard" compatible. It is basically a mixture of
> the apq8016-sbc-sndcard and the newer sm8250-sndcard, which uses
> indirect QDSP6 DAI links instead of the direct LPASS DAI links.
>
> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
> ---
> .../bindings/sound/qcom,sm8250.yaml | 42 +++++++++++++++++++
> 1 file changed, 42 insertions(+)
>

Reviewed-by: Rob Herring <robh@kernel.org>