Subject: Re: [PATCH v2 3/7] ASoC: dt-bindings: fsl_rpmsg: Add binding doc for rpmsg cpu dai driver

From: Rob Herring <[email-masked]>
Date: Wed, 10 Feb 2021 16:12:52 -0600

On Sun, Feb 07, 2021 at 06:23:51PM +0800, Shengjiu Wang wrote:
> fsl_rpmsg cpu dai driver is driver for rpmsg audio, which is mainly used
> for getting the user's configuration from device tree and configure the
> clocks which is used by Cortex-M core. So in this document define the
> needed property.
> 
> Signed-off-by: Shengjiu Wang <[email-masked]>
> ---
>  .../devicetree/bindings/sound/fsl,rpmsg.yaml  | 80 +++++++++++++++++++
>  1 file changed, 80 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/sound/fsl,rpmsg.yaml
> 
> diff --git a/Documentation/devicetree/bindings/sound/fsl,rpmsg.yaml b/Documentation/devicetree/bindings/sound/fsl,rpmsg.yaml
> new file mode 100644
> index 000000000000..2d3ce10d42fc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/sound/fsl,rpmsg.yaml
> @@ -0,0 +1,80 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/sound/fsl,rpmsg.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP Audio RPMSG CPU DAI Controller
> +
> +maintainers:
> +  - Shengjiu Wang <[email-masked]>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - fsl,imx7ulp-rpmsg
> +      - fsl,imx8mn-rpmsg
> +      - fsl,imx8mm-rpmsg
> +      - fsl,imx8mp-rpmsg

rpmsg is a protocol. What's the h/w block?

> +
> +  clocks:
> +    items:
> +      - description: Peripheral clock for register access
> +      - description: Master clock
> +      - description: DMA clock for DMA register access
> +      - description: Parent clock for multiple of 8kHz sample rates
> +      - description: Parent clock for multiple of 11kHz sample rates
> +    minItems: 5
> +
> +  clock-names:
> +    items:
> +      - const: ipg
> +      - const: mclk
> +      - const: dma
> +      - const: pll8k
> +      - const: pll11k
> +    minItems: 5
> +
> +  power-domains:
> +    maxItems: 1
> +
> +  fsl,audioindex:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: instance index for rpmsg image
> +
> +  fsl,version:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: rpmsg image version index

What are these 2 used for?

> +
> +  fsl,buffer-size:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: pre allocate dma buffer size
> +
> +  fsl,enable-lpa:
> +    $ref: /schemas/types.yaml#/definitions/flag
> +    description: enable low power audio path.
> +
> +  fsl,codec-type:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: Sometimes the codec is registered by
> +                 driver not the device tree, this items
> +                 can be used to distinguish codecs

0-2^32 are valid values?

> +
> +required:
> +  - compatible
> +  - fsl,audioindex
> +  - fsl,version
> +  - fsl,buffer-size
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    rpmsg_audio: rpmsg_audio {
> +        compatible = "fsl,imx8mn-rpmsg";
> +        fsl,audioindex = <0> ;
> +        fsl,version = <2>;
> +        fsl,buffer-size = <0x6000000>;
> +        fsl,enable-lpa;
> +        status = "okay";

Don't show status in examples.

> +    };
> -- 
> 2.27.0