On Thu, 23 Mar 2023 08:31:28 +0100 Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote: > On 23/03/2023 08:27, Herve Codina wrote: > > Hi Krzysztof > > > > On Wed, 22 Mar 2023 22:59:37 +0100 > > Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote: > > > >> On 22/03/2023 14:46, Herve Codina wrote: > >>> The Lantiq PEF2256 is a framer and line interface component designed to > >>> fulfill all required interfacing between an analog E1/T1/J1 line and the > >>> digital PCM system highway/H.100 bus. > >>> > >>> The codec support allows to use some of the PCM system highway > >>> time-slots as audio channels to transport audio data over the E1/T1/J1 > >>> lines. > >>> > >>> Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx> > >>> --- > >>> .../bindings/sound/lantiq,pef2256-codec.yaml | 54 +++++++++++++++++++ > >>> 1 file changed, 54 insertions(+) > >>> create mode 100644 Documentation/devicetree/bindings/sound/lantiq,pef2256-codec.yaml > >>> > >>> diff --git a/Documentation/devicetree/bindings/sound/lantiq,pef2256-codec.yaml b/Documentation/devicetree/bindings/sound/lantiq,pef2256-codec.yaml > >>> new file mode 100644 > >>> index 000000000000..da35b70cda99 > >>> --- /dev/null > >>> +++ b/Documentation/devicetree/bindings/sound/lantiq,pef2256-codec.yaml > >>> @@ -0,0 +1,54 @@ > >>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > >>> +%YAML 1.2 > >>> +--- > >>> +$id: http://devicetree.org/schemas/sound/lantiq,pef2256-codec.yaml# > >>> +$schema: http://devicetree.org/meta-schemas/core.yaml# > >>> + > >>> +title: Lantiq PEF2256 codec > >>> + > >>> +maintainers: > >>> + - Herve Codina <herve.codina@xxxxxxxxxxx> > >>> + > >>> +description: | > >>> + Codec support for PEF2256. > >>> + > >>> + The Lantiq PEF2256, also known as Infineon PEF2256 or FALC56, is a framer and > >>> + line interface component designed to fulfill all required interfacing between > >>> + an analog E1/T1/J1 line and the digital PCM system highway/H.100 bus. > >>> + > >>> + The codec support allows to use some of the PCM system highway time-slots as > >>> + audio channels to transport audio data over the E1/T1/J1 lines. > >>> + > >>> + The time-slots used by the codec must be set and so, the properties > >>> + 'dai-tdm-slot-num', 'dai-tdm-slot-width', 'dai-tdm-slot-tx-mask' and > >>> + 'dai-tdm-slot-rx-mask' must be present in the ALSA sound card node for > >>> + sub-nodes that involve the codec. The codec uses 8bit time-slots. > >>> + 'dai-tdm-tdm-slot-with' must be set to 8. > >>> + The tx and rx masks define the PEF2256 time-slots assigned to the codec. > >>> + > >>> + The PEF2256 codec node should be a child of a PEF2256 node. > >>> + Refer to the bindings described in > >>> + Documentation/devicetree/bindings/mfd/lantiq,pef2256.yaml > >>> + > >>> +allOf: > >>> + - $ref: dai-common.yaml# > >>> + > >>> +properties: > >>> + compatible: > >>> + const: lantiq,pef2256-codec > >>> + > >>> + '#sound-dai-cells': > >>> + const: 0 > >> > >> You do not have here any resources, so the entire binding can be dropped > >> and merged into the parent. > >> > >> Best regards, > >> Krzysztof > >> > > > > Ok, > > Do you expect all these properties (except compatible) merged at the parent > > You have only two properties here - dai cells and name-prefix... > > > level or may I keep a child node with these properties including the > > compatible property (ie. yaml file merge). > > I was thinking that these should be merged into parent because usually > you do not need child node for this. However now I started to think how > the codec driver would look like. Essentially the parent MFD driver > would need to register dais... > There is also something specific to audio, the slots definition 'dai-tdm-slot-tx-mask' and 'dai-tdm-slot-rx-mask'. These slots definitions are set at the ALSA sound card sub-nodes. So, I can have multiple codec in the PEF2256. For instance: framer { compatible = "lantiq,pef2256", "simple-mfd"; ... pef2256_codec0: codec0 { compatible = "lantiq,pef2256-codec"; #sound-dai-cells = <0>; }; pef2256_codec1: codec1 { compatible = "lantiq,pef2256-codec"; #sound-dai-cells = <0>; }; }; sound { compatible = "simple-audio-card"; #address-cells = <1>; #size-cells = <0>; simple-audio-card,dai-link@0 { /* CPU DAI1 - pef2256 codec 1 */ reg = <0>; cpu { sound-dai = <&cpu_dai1>; }; codec { sound-dai = <&pef2256_codec0>; dai-tdm-slot-num = <4>; dai-tdm-slot-width = <8>; /* TS 2, 3, 4, 5 */ dai-tdm-slot-tx-mask = <0 1 1 1 1>; dai-tdm-slot-rx-mask = <0 1 1 1 1>; }; simple-audio-card,dai-link@1 { /* CPU DAI2 - pef2256 codec 2 */ reg = <1>; cpu { sound-dai = <&cpu_dai2>; }; codec { sound-dai = <&pef2256_codec1>; dai-tdm-slot-num = <4>; dai-tdm-slot-width = <8>; /* TS 6, 7, 8, 9 */ dai-tdm-slot-tx-mask = <0 0 0 0 0 1 1 1 1>; dai-tdm-slot-rx-mask = <0 0 0 0 0 1 1 1 1>; }; }; }; To solve this, I can use #sound-dai-cells = <1>; but this will complicate the driver itself and is it really needed ? Having "simple-mfd" dans sub-nodes keep all things simple. Regards, Hervé -- Hervé Codina, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
