54e49a3c9d
Merge series from Elinor Montmasson <elinor.montmasson@savoirfairelinux.com>: This is a series of patches aiming to make the machine driver `fsl-asoc-card` compatible with S/PDIF controllers on imx boards. The main goal is to allow the use of S/PDIF controllers with ASRC modules. The `imx-spdif` machine driver already has specific support for S/PDIF controllers but doesn't support using an ASRC with it. However, the `fsl-asoc-card` machine driver has the necessary code to create a sound card which can use an ASRC module. It is then possible to extend the support for S/PDIF audio cards by merging the `imx-spdif` driver into `fsl-asoc-card`. The first three patches adapt the `fsl-asoc-card` driver to support multiple codec use cases. The driver can get 2 codec phandles from the device tree, and codec-related variables are doubled. `for_each_codecs` macros are also used when possible to ease adding other multi-codec use cases in the future. It makes possible to use the two S/PDIF dummy codec drivers `spdif_receiver` and `spdif_transmitter` instead of `snd-soc-dummy`, which was used in `imx-spdif`. The fourth patch merges the S/PDIF support from `imx-spdif` to `fsl-asoc-card`. `fsl-asoc-card` offers the same functionalities as `imx-spdif` did, but this merge also extends the S/PDIF support with the possibility of using an ASRC. Compatible "fsl,imx-audio-spdif" is kept, but `fsl-asoc-card` uses different DT properties compared to `imx-spdif`: * The "spdif-controller" property from `imx-spdif` is named "audio-cpu" in `fsl-asoc-card`. * `fsl-asoc-card` uses codecs explicitly declared in DT with "audio-codec". With an S/PDIF, codec drivers `spdif_transmitter` and `spdif_receiver` should be used. Driver `imx-spdif` used instead the dummy codec and a pair of boolean properties, "spdif-in" and "spdif-out". Backward compatibility is therefore implemented in `fsl-asoc-card`. However, it is recommended to use the new properties when needed. Especially, declaring and using S/PDIF transmitter and/or receiver nodes is better than using the dummy codec. The last three patches update the device tree bindings of `fsl-asoc-card` and update all in-tree device trees to use the `fsl-asoc-card` properties. Note that as the old properties are still supported: * previous versions of in-tree device trees are still supported. * out-of-tree device trees are still supported. This series of patches was successfully built for arm64 and x86 on top of the latest "for-next" branch of the ASoC git tree on the 26th of June 2024. These modifications have also been tested on an i.MX8MN evaluation board with a linux kernel RT v6.1.26-rt8.
Linux kernel
============
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