Re: [PATCHv3 RESEND 10/10] ASoC: dt-bindings: fsl-asoc-card: add compatible for generic codec

From: Rob Herring
Date: Wed Dec 20 2023 - 17:26:03 EST


On Mon, Dec 18, 2023 at 01:40:58PM +0100, Elinor Montmasson wrote:
> Add documentation about new dts bindings following new support
> for compatible "fsl,imx-audio-generic".
>
> Some CPU DAI don't require a real audio codec. The new compatible
> "fsl,imx-audio-generic" allows using the driver with codec drivers
> SPDIF DIT and SPDIF DIR as dummy codecs.
> It also allows using not pre-configured audio codecs which
> don't require specific control through a codec driver.
>
> The new dts properties give the possibility to set some parameters
> about the CPU DAI usually set through the codec configuration.
>
> Signed-off-by: Elinor Montmasson <elinor.montmasson@xxxxxxxxxxxxxxxxxxxx>
> Co-authored-by: Philip-Dylan Gleonec <philip-dylan.gleonec@xxxxxxxxxxxxxxxxxxxx>
> ---
> .../bindings/sound/fsl-asoc-card.txt | 28 ++++++++++++++++++-
> 1 file changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/sound/fsl-asoc-card.txt b/Documentation/devicetree/bindings/sound/fsl-asoc-card.txt
> index 4e8dbc5abfd1..f137ef2154e3 100644
> --- a/Documentation/devicetree/bindings/sound/fsl-asoc-card.txt
> +++ b/Documentation/devicetree/bindings/sound/fsl-asoc-card.txt
> @@ -17,6 +17,9 @@ Note: The card is initially designed for those sound cards who use AC'97, I2S
> and PCM DAI formats. However, it'll be also possible to support those non
> AC'97/I2S/PCM type sound cards, such as S/PDIF audio and HDMI audio, as
> long as the driver has been properly upgraded.
> + To use CPU DAIs that do not require a codec such as an S/PDIF controller,
> + or to use a DAI to output or capture raw I2S/TDM data, you can
> + use the compatible "fsl,imx-audio-generic".
>
>
> The compatible list for this generic sound card currently:
> @@ -48,6 +51,8 @@ The compatible list for this generic sound card currently:
>
> "fsl,imx-audio-nau8822"
>
> + "fsl,imx-audio-generic"
> +
> Required properties:
>
> - compatible : Contains one of entries in the compatible list.
> @@ -56,7 +61,11 @@ Required properties:
>
> - audio-cpu : The phandle of an CPU DAI controller
>
> - - audio-codec : The phandle of an audio codec
> + - audio-codec : The phandle of an audio codec.
> + If using the "fsl,imx-audio-generic" compatible,
> + give instead a pair of phandles with the
> + spdif_transmitter first (driver SPDIF DIT) and the
> + spdif_receiver second (driver SPDIF DIR).
>
> Optional properties:
>
> @@ -87,6 +96,23 @@ Optional properties:
> - frame-inversion : dai-link uses frame clock inversion, for details see simple-card.yaml.
> - bitclock-inversion : dai-link uses bit clock inversion, for details see simple-card.yaml.
> - mclk-id : main clock id, specific for each card configuration.
> + For multi-codec configurations, an array of ids can be
> + given, one for each codec.
> +
> +Optional, relevant only with the "fsl,imx-audio-generic" compatible:
> +
> + - cpu-slot-width : Indicates a specific TDM slot width in bits.
> + - cpu-slot-num : Indicates a specific number of TDM slots per frame.

Pretty sure I've seen other bindings with TDM slot properties. A sign we
need something common if we don't already have something.

> +
> + - cpu-sysclk-freq-rx : Frequency of the CPU DAI sys clock for Rx.
> + - cpu-sysclk-freq-tx : Frequency of the CPU DAI sys clock for Tx.
> +
> + - cpu-sysclk-dir-rx-out : Boolean property. Specifies sys clock direction
> + as 'out' on initialization for Rx.
> + If not set, default direction is 'in'.
> + - cpu-sysclk-dir-tx-out : Boolean property. Specifies sys clock direction
> + as 'out' on initialization for Tx.
> + If not set, default direction is 'in'.

Looks like clock stuff. Use the clock binding.

Rob