Hi Rob,
On Tue, 20 Jun 2023 10:45:21 -0600 Rob Herring robh@kernel.org wrote:
On Thu, Jun 15, 2023 at 05:26:20PM +0200, Herve Codina wrote:
The additional-devs subnode allows to declared some virtual devices as sound card children. These virtual devices can then be used by the sound card and so be present in the audio path.
The first virtual device supported is the audio IIO auxiliary device in order to support an IIO device as an audio auxiliary device.
Signed-off-by: Herve Codina herve.codina@bootlin.com
.../bindings/sound/simple-card.yaml | 53 +++++++++++++++++++ 1 file changed, 53 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/simple-card.yaml b/Documentation/devicetree/bindings/sound/simple-card.yaml index b05e05c81cc4..59ac2d1d1ccf 100644 --- a/Documentation/devicetree/bindings/sound/simple-card.yaml +++ b/Documentation/devicetree/bindings/sound/simple-card.yaml @@ -148,6 +148,15 @@ definitions: required: - sound-dai
- additional-devs:
- type: object
- description:
Additional devices used by the simple audio card.- patternProperties:
'^iio-aux(-.+)?$':type: object$ref: audio-iio-aux.yaml#properties: compatible: contains: @@ -187,6 +196,8 @@ properties: $ref: "#/definitions/mclk-fs" simple-audio-card,aux-devs: $ref: "#/definitions/aux-devs"
- simple-audio-card,additional-devs:
- $ref: "#/definitions/additional-devs"
Why do you need this under the card node? Can't you just use the existing aux-devs?
aux-devs is a phandle array referencing auxiliary devices. I cannot define a node with just aux-devs, just reference.
I need device auxiliary devices that are not defined somewhere else in the DT.
A SPI amplifier is defined as a subnode of a SPI controler. But my IIO/ASoC virtual devices are not defined under some hardware bus. I need to define them here, as a simple-audio-card subnode.
Several subnodes are already defined for a simple-audio-card subnode for other purpose.
Instead of having virtual device nodes directly as chidren mixed with the other purpose nodes of the simple-audio-card, I group them under the additional-devs node in order to ease evolution and maintenance.
Best regards, Hervé
simple-audio-card,convert-rate: $ref: "#/definitions/convert-rate" simple-audio-card,convert-channels: @@ -359,6 +370,48 @@ examples: }; };
+# -------------------- +# route audio to/from a codec through an amplifier +# designed with a potentiometer driven by IIO: +# --------------------
- |
- sound {
compatible = "simple-audio-card";simple-audio-card,aux-devs = <&_in>, <&_out>;simple-audio-card,routing ="CODEC LEFTIN", "AMP_IN LEFT OUT","CODEC RIGHTIN", "AMP_IN RIGHT OUT","AMP_OUT LEFT IN", "CODEC LEFTOUT","AMP_OUT RIGHT IN", "CODEC RIGHTOUT";simple-audio-card,additional-devs {amp_out: iio-aux-out {compatible = "audio-iio-aux";io-channels = <&pot_out 0>, <&pot_out 1>;io-channel-names = "LEFT", "RIGHT";snd-control-invert-range = <1 1>;sound-name-prefix = "AMP_OUT";};amp_in: iio_aux-in {compatible = "audio-iio-aux";io-channels = <&pot_in 0>, <&pot_in 1>;io-channel-names = "LEFT", "RIGHT";sound-name-prefix = "AMP_IN";};};simple-audio-card,cpu {sound-dai = <&cpu>;};simple-audio-card,codec {sound-dai = <&codec>;clocks = <&clocks>;};- };
# -------------------- # Sampling Rate Conversion
# --------------------
2.40.1