Hi Rob, On Tue, 25 Apr 2023 12:30:29 -0500 Rob Herring <robh@xxxxxxxxxx> wrote: > On Fri, Apr 21, 2023 at 02:41:19PM +0200, Herve Codina wrote: > > Industrial I/O devices can be present in the audio path. > > These devices needs to be viewed as audio components in order to be > > fully integrated in the audio path. > > > > simple-iio-aux allows to consider these Industrial I/O devices as > > auxliary audio devices. > > What makes it simple? Any binding called simple or generic is a trigger > for me. Best to avoid those terms. :) I choose simple-iio-aux because some simple-* already exists. For instance simple-audio-amplifier or simple-audio-mux. Do you prefer audio-iio-aux ? Let me know if I should change. > > Examples of devices would be useful here. > > > > > Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx> > > --- > > .../bindings/sound/simple-iio-aux.yaml | 65 +++++++++++++++++++ > > 1 file changed, 65 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/sound/simple-iio-aux.yaml > > > > diff --git a/Documentation/devicetree/bindings/sound/simple-iio-aux.yaml b/Documentation/devicetree/bindings/sound/simple-iio-aux.yaml > > new file mode 100644 > > index 000000000000..fab128fce4fc > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/sound/simple-iio-aux.yaml > > @@ -0,0 +1,65 @@ > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/sound/simple-iio-aux.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: Simple IIO auxiliary > > + > > +maintainers: > > + - Herve Codina <herve.codina@xxxxxxxxxxx> > > + > > +description: | > > Don't need '|' Will be fixed. > > > + Auxiliary device based on Industrial I/O device channels > > + > > +allOf: > > + - $ref: /schemas/iio/iio-consumer.yaml > > You don't need to reference consumer schemas. Right, will be removed. > > > + - $ref: dai-common.yaml# > > + > > +properties: > > + compatible: > > + const: simple-iio-aux > > + > > + io-channels: > > + description: > > + Industrial I/O device channels used > > + > > + io-channel-names: > > + description: > > + Industrial I/O channel names related to io-channels. > > + These names are used to provides sound controls, widgets and routes names. > > + > > + invert: > > Property names should globally only have 1 type definition. This is > generic enough I'd be concerned that's not the case. What do you mean ? > > > + $ref: /schemas/types.yaml#/definitions/uint32-array > > + description: | > > + A list of 0/1 flags defining whether or not the related channel is > > + inverted > > + items: > > + enum: [0, 1] > > + default: 0 > > + description: | > > + Invert the sound control value compared to the IIO channel raw value. > > + - 1: The related sound control value is inverted meaning that the > > + minimum sound control value correspond to the maximum IIO channel > > + raw value and the maximum sound control value correspond to the > > + minimum IIO channel raw value. > > + - 0: The related sound control value is not inverted meaning that the > > + minimum (resp maximum) sound control value correspond to the > > + minimum (resp maximum) IIO channel raw value. > > + > > +required: > > + - compatible > > + - io-channels > > + - io-channel-names > > + > > +unevaluatedProperties: false > > + > > +examples: > > + - | > > + aux { > > + compatible = "simple-iio-aux"; > > + io-channels = <&iio 0>, <&iio 1>, <&iio 2>, <&iio 3>; > > + io-channel-names = "CH0", "CH1", "CH2", "CH3"; > > Not really useful names. Do you have a real example? As Mark said, for IIO channel, using CHx makes sense. See below, I provide a full example. > > > + /* Invert CH1 and CH2 */ > > + invert = <0 1 1>; > > IMO, invert should be same length as io-channels. I will update. Related to this topic, when I wrote this binding, I wanted to add some rules/constraints in order to: - Have this property optional - If present, force to have as many items in the invert array as the number of items present in the io-channels array. I never succeed in writing the constraint for the invert property. It should be possible (it is done for some 'foo' 'foo-names' pair such as clocks). Can you tell me if possible in my case and give me some pointers ? > > > + }; > > How do support multiple instances? Say you have 2 sound cards (or 1 > sound card with multiple audio paths) each with different sets of IIO > channels associated with it. You'd need a link to each 'aux' node. Why > not just add io-channels to the sound card nodes directly? That's > already just a virtual, top-level container node grouping all the > components. I don't see why we need another virtual node grouping a > subset of them. I don't see what you mean. I use a simple-audio-card and here is a full example using several instances: spi { #address-cells = <1>; #size-cells = <0>; /* potentiometers present in an input amplifier design */ pot_in: potentiometer@0 { compatible = "foo,xxx"; reg = <0>; #io-channel-cells = <1>; }; /* potentiometers present in an output amplifier design */ pot_out: potentiometer@1 { compatible = "foo,xxx"; reg = <1>; #io-channel-cells = <1>; }; /* A codec */ codec: codec@2 { compatible = "bar,yyy"; reg = <2>; sound-name-prefix = "CODEC"; }; }; amp_out: aux-out { compatible = "simple-iio-aux"; io-channels = <&pot_out 0>, <&pot_out 1>, io-channel-names = "CH0", "CH1"; invert = <1 1>; sound-name-prefix = "AMP_OUT"; }; amp_in: aux-in { compatible = "simple-iio-aux"; io-channels = <&pot_in 0>, <&pot_in 1>; io-channel-names = "CH0", "CH1"; sound-name-prefix = "AMP_IN"; }; sound { compatible = "simple-audio-card"; #address-cells = <1>; #size-cells = <0>; simple-audio-card,name = "My Sound Card"; simple-audio-card,aux-devs = <&_in>, <&_out>; simple-audio-card,routing = "CODEC IN0", "AMP_IN CH0 OUT", "CODEC IN1", "AMP_IN CH1 OUT", "AMP_OUT CH0 IN", "CODEC OUT0", "AMP_OUT CH1 IN", "CODEC OUT1", simple-audio-card,dai-link@0 { ... }; }; Best regards, Hervé -- Hervé Codina, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
