[v2,7/7] ASoC: dt-bindings: imx-rpmsg: Add binding doc for rpmsg machine driver

Imx-rpmsg is a new added machine driver for supporting audio on Cortex-M
core. The Cortex-M core will control the audio interface, DMA and audio
codec, setup the pipeline, the audio driver on Cortex-A core side is just
to communitcate with M core, it is a virtual sound card and don't touch
the hardware.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 .../bindings/sound/imx-audio-rpmsg.yaml       | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sound/imx-audio-rpmsg.yaml

On Sun, Feb 07, 2021 at 06:23:55PM +0800, Shengjiu Wang wrote:
> Imx-rpmsg is a new added machine driver for supporting audio on Cortex-M
> core. The Cortex-M core will control the audio interface, DMA and audio
> codec, setup the pipeline, the audio driver on Cortex-A core side is just
> to communitcate with M core, it is a virtual sound card and don't touch
> the hardware.

I don't understand why there are 2 nodes for this other than you happen 
to want to split this into 2 Linux drivers. It's 1 h/w thing. 

> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> ---
>  .../bindings/sound/imx-audio-rpmsg.yaml       | 48 +++++++++++++++++++
>  1 file changed, 48 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/sound/imx-audio-rpmsg.yaml
> 
> diff --git a/Documentation/devicetree/bindings/sound/imx-audio-rpmsg.yaml b/Documentation/devicetree/bindings/sound/imx-audio-rpmsg.yaml
> new file mode 100644
> index 000000000000..b941aeb80678
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/sound/imx-audio-rpmsg.yaml
> @@ -0,0 +1,48 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/sound/imx-audio-rpmsg.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP i.MX audio complex with rpmsg
> +
> +maintainers:
> +  - Shengjiu Wang <shengjiu.wang@nxp.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - fsl,imx-audio-rpmsg
> +
> +  model:
> +    $ref: /schemas/types.yaml#/definitions/string
> +    description: User specified audio sound card name
> +
> +  audio-cpu:
> +    description: The phandle of an CPU DAI controller
> +
> +  rpmsg-out:
> +    description: |
> +      This is a boolean property. If present, the transmitting function
> +      will be enabled,
> +
> +  rpmsg-in:
> +    description: |
> +      This is a boolean property. If present, the receiving function
> +      will be enabled.
> +
> +required:
> +  - compatible
> +  - model
> +  - audio-cpu
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    sound-rpmsg {
> +        compatible = "fsl,imx-audio-rpmsg";
> +        model = "ak4497-audio";
> +        audio-cpu = <&rpmsg_audio>;
> +        rpmsg-out;
> +    };
> -- 
> 2.27.0
>

On Thu, Feb 11, 2021 at 6:18 AM Rob Herring <robh@kernel.org> wrote:
>
> On Sun, Feb 07, 2021 at 06:23:55PM +0800, Shengjiu Wang wrote:
> > Imx-rpmsg is a new added machine driver for supporting audio on Cortex-M
> > core. The Cortex-M core will control the audio interface, DMA and audio
> > codec, setup the pipeline, the audio driver on Cortex-A core side is just
> > to communitcate with M core, it is a virtual sound card and don't touch
> > the hardware.
>
> I don't understand why there are 2 nodes for this other than you happen
> to want to split this into 2 Linux drivers. It's 1 h/w thing.

This one is for the sound card machine driver.  Another one is
for the sound card cpu dai driver. so there are 2 nodes.

>
> >
> > Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> > ---
> >  .../bindings/sound/imx-audio-rpmsg.yaml       | 48 +++++++++++++++++++
> >  1 file changed, 48 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/sound/imx-audio-rpmsg.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/sound/imx-audio-rpmsg.yaml b/Documentation/devicetree/bindings/sound/imx-audio-rpmsg.yaml
> > new file mode 100644
> > index 000000000000..b941aeb80678
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/sound/imx-audio-rpmsg.yaml
> > @@ -0,0 +1,48 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/sound/imx-audio-rpmsg.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: NXP i.MX audio complex with rpmsg
> > +
> > +maintainers:
> > +  - Shengjiu Wang <shengjiu.wang@nxp.com>
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - fsl,imx-audio-rpmsg
> > +
> > +  model:
> > +    $ref: /schemas/types.yaml#/definitions/string
> > +    description: User specified audio sound card name
> > +
> > +  audio-cpu:
> > +    description: The phandle of an CPU DAI controller
> > +
> > +  rpmsg-out:
> > +    description: |
> > +      This is a boolean property. If present, the transmitting function
> > +      will be enabled,
> > +
> > +  rpmsg-in:
> > +    description: |
> > +      This is a boolean property. If present, the receiving function
> > +      will be enabled.
> > +
> > +required:
> > +  - compatible
> > +  - model
> > +  - audio-cpu
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    sound-rpmsg {
> > +        compatible = "fsl,imx-audio-rpmsg";
> > +        model = "ak4497-audio";
> > +        audio-cpu = <&rpmsg_audio>;
> > +        rpmsg-out;
> > +    };
> > --
> > 2.27.0
> >

On Thu, Feb 18, 2021 at 1:23 AM Shengjiu Wang <shengjiu.wang@gmail.com> wrote:
>
> On Thu, Feb 11, 2021 at 6:18 AM Rob Herring <robh@kernel.org> wrote:
> >
> > On Sun, Feb 07, 2021 at 06:23:55PM +0800, Shengjiu Wang wrote:
> > > Imx-rpmsg is a new added machine driver for supporting audio on Cortex-M
> > > core. The Cortex-M core will control the audio interface, DMA and audio
> > > codec, setup the pipeline, the audio driver on Cortex-A core side is just
> > > to communitcate with M core, it is a virtual sound card and don't touch
> > > the hardware.
> >
> > I don't understand why there are 2 nodes for this other than you happen
> > to want to split this into 2 Linux drivers. It's 1 h/w thing.
>
> This one is for the sound card machine driver.  Another one is
> for the sound card cpu dai driver. so there are 2 nodes.

You are explaining this to me in terms of drivers. Explain it in terms
of h/w blocks.

Rob

Hi

On Fri, Mar 5, 2021 at 4:05 AM Rob Herring <robh@kernel.org> wrote:
>
> On Thu, Feb 18, 2021 at 1:23 AM Shengjiu Wang <shengjiu.wang@gmail.com> wrote:
> >
> > On Thu, Feb 11, 2021 at 6:18 AM Rob Herring <robh@kernel.org> wrote:
> > >
> > > On Sun, Feb 07, 2021 at 06:23:55PM +0800, Shengjiu Wang wrote:
> > > > Imx-rpmsg is a new added machine driver for supporting audio on Cortex-M
> > > > core. The Cortex-M core will control the audio interface, DMA and audio
> > > > codec, setup the pipeline, the audio driver on Cortex-A core side is just
> > > > to communitcate with M core, it is a virtual sound card and don't touch
> > > > the hardware.
> > >
> > > I don't understand why there are 2 nodes for this other than you happen
> > > to want to split this into 2 Linux drivers. It's 1 h/w thing.
> >
> > This one is for the sound card machine driver.  Another one is
> > for the sound card cpu dai driver. so there are 2 nodes.
>
> You are explaining this to me in terms of drivers. Explain it in terms
> of h/w blocks.
>

Yes, there is only 1 h/w block, which is (MU) message unit

As the sound card needs a cpu dai node and sound card node,
so from the driver's perspective, I use two nodes.

Seems It is hard to only use one node for my case.
or do you have any suggestions?

Best regards
Wang shengjiu