ASoC: fsl-asoc-card: add S/PDIF controller support

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.

Documentation/devicetree/bindings/sound/fsl,imx-audio-spdif.yaml

-# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
-%YAML 1.2
----
-$id: http://devicetree.org/schemas/sound/fsl,imx-audio-spdif.yaml#
-$schema: http://devicetree.org/meta-schemas/core.yaml#
-
-title: Freescale i.MX audio complex with S/PDIF transceiver
-
-maintainers:
-  - Shengjiu Wang <shengjiu.wang@nxp.com>
-
-properties:
-  compatible:
-    oneOf:
-      - items:
-          - enum:
-              - fsl,imx-sabreauto-spdif
-              - fsl,imx6sx-sdb-spdif
-          - const: fsl,imx-audio-spdif
-      - enum:
-          - fsl,imx-audio-spdif
-
-  model:
-    $ref: /schemas/types.yaml#/definitions/string
-    description: User specified audio sound card name
-
-  spdif-controller:
-    $ref: /schemas/types.yaml#/definitions/phandle
-    description: The phandle of the i.MX S/PDIF controller
-
-  spdif-out:
-    type: boolean
-    description:
-      If present, the transmitting function of S/PDIF will be enabled,
-      indicating there's a physical S/PDIF out connector or jack on the
-      board or it's connecting to some other IP block, such as an HDMI
-      encoder or display-controller.
-
-  spdif-in:
-    type: boolean
-    description:
-      If present, the receiving function of S/PDIF will be enabled,
-      indicating there is a physical S/PDIF in connector/jack on the board.
-
-required:
-  - compatible
-  - model
-  - spdif-controller
-
-anyOf:
-  - required:
-      - spdif-in
-  - required:
-      - spdif-out
-
-additionalProperties: false
-
-examples:
-  - |
-    sound-spdif {
-        compatible = "fsl,imx-audio-spdif";
-        model = "imx-spdif";
-        spdif-controller = <&spdif>;
-        spdif-out;
-        spdif-in;
-    };

Documentation/devicetree/bindings/sound/fsl-asoc-card.yaml

@@ -65,6 +65,11 @@ properties:
               - fsl,imx-audio-sgtl5000
               - fsl,imx-audio-wm8960
               - fsl,imx-audio-wm8962
+      - items:
+          - enum:
+              - fsl,imx-sabreauto-spdif
+              - fsl,imx6sx-sdb-spdif
+          - const: fsl,imx-audio-spdif
       - items:
           - enum:
               - fsl,imx-audio-ac97
@@ -81,6 +86,7 @@ properties:
               - fsl,imx-audio-wm8960
               - fsl,imx-audio-wm8962
               - fsl,imx-audio-wm8958
+              - fsl,imx-audio-spdif
 
   model:
     $ref: /schemas/types.yaml#/definitions/string
@@ -93,8 +99,15 @@ properties:
       need to add ASRC support via DPCM.
 
   audio-codec:
-    $ref: /schemas/types.yaml#/definitions/phandle
-    description: The phandle of an audio codec
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description: |
+      The phandle of an audio codec.
+      With "fsl,imx-audio-spdif", either SPDIF audio codec spdif_transmitter,
+      spdif_receiver or both.
+    minItems: 1
+    maxItems: 2
+    items:
+      maxItems: 1
 
   audio-cpu:
     $ref: /schemas/types.yaml#/definitions/phandle
@@ -150,8 +163,10 @@ properties:
     description: dai-link uses bit clock inversion.
 
   mclk-id:
-    $ref: /schemas/types.yaml#/definitions/uint32
-    description: main clock id, specific for each card configuration.
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    description: Main clock id for each codec, specific for each card configuration.
+    minItems: 1
+    maxItems: 2
 
   mux-int-port:
     $ref: /schemas/types.yaml#/definitions/uint32
@@ -167,6 +182,27 @@ properties:
     $ref: /schemas/types.yaml#/definitions/phandle
     description: The phandle of an CPU DAI controller
 
+  spdif-controller:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    deprecated: true
+    description: The phandle of an S/PDIF CPU DAI controller.
+
+  spdif-out:
+    type: boolean
+    deprecated: true
+    description: |
+      If present, the transmitting function of S/PDIF will be enabled,
+      indicating there's a physical S/PDIF out connector or jack on the
+      board or it's connecting to some other IP block, such as an HDMI
+      encoder or display-controller.
+
+  spdif-in:
+    type: boolean
+    deprecated: true
+    description: |
+      If present, the receiving function of S/PDIF will be enabled,
+      indicating there is a physical S/PDIF in connector/jack on the board.
+
 required:
   - compatible
   - model
@@ -195,3 +231,12 @@ examples:
              "AIN2L", "Line In Jack",
              "AIN2R", "Line In Jack";
     };
+
+  - |
+    sound-spdif-asrc {
+        compatible = "fsl,imx-audio-spdif";
+        model = "spdif-asrc-audio";
+        audio-cpu = <&spdif>;
+        audio-asrc = <&easrc>;
+        audio-codec = <&spdifdit>, <&spdifdir>;
+    };

arch/arm/configs/imx_v6_v7_defconfig

@@ -311,7 +311,6 @@ CONFIG_SND_IMX_SOC=y
 CONFIG_SND_SOC_EUKREA_TLV320=y
 CONFIG_SND_SOC_IMX_ES8328=y
 CONFIG_SND_SOC_IMX_SGTL5000=y
-CONFIG_SND_SOC_IMX_SPDIF=y
 CONFIG_SND_SOC_FSL_ASOC_CARD=y
 CONFIG_SND_SOC_AC97_CODEC=y
 CONFIG_SND_SOC_CS42XX8_I2C=y

arch/arm64/configs/defconfig

@@ -940,7 +940,6 @@ CONFIG_SND_SOC_FSL_MICFIL=m
 CONFIG_SND_SOC_FSL_EASRC=m
 CONFIG_SND_IMX_SOC=m
 CONFIG_SND_SOC_IMX_SGTL5000=m
-CONFIG_SND_SOC_IMX_SPDIF=m
 CONFIG_SND_SOC_FSL_ASOC_CARD=m
 CONFIG_SND_SOC_IMX_AUDMIX=m
 CONFIG_SND_SOC_MT8183=m

sound/soc/fsl/Kconfig

@@ -303,15 +303,6 @@ config SND_SOC_IMX_SGTL5000
 	  SND_SOC_FSL_ASOC_CARD and SND_SOC_SGTL5000 to use the newer
 	  driver.
 
-config SND_SOC_IMX_SPDIF
-	tristate "SoC Audio support for i.MX boards with S/PDIF"
-	select SND_SOC_IMX_PCM_DMA
-	select SND_SOC_FSL_SPDIF
-	help
-	  SoC Audio support for i.MX boards with S/PDIF
-	  Say Y if you want to add support for SoC audio on an i.MX board with
-	  a S/DPDIF.
-
 config SND_SOC_FSL_ASOC_CARD
 	tristate "Generic ASoC Sound Card with ASRC support"
 	depends on OF && I2C
@@ -323,6 +314,7 @@ config SND_SOC_FSL_ASOC_CARD
 	select SND_SOC_FSL_ESAI
 	select SND_SOC_FSL_SAI
 	select SND_SOC_FSL_SSI
+	select SND_SOC_FSL_SPDIF
 	select SND_SOC_TLV320AIC31XX
 	select SND_SOC_WM8994
 	select MFD_WM8994

sound/soc/fsl/Makefile

@@ -67,7 +67,6 @@ obj-$(CONFIG_SND_SOC_IMX_PCM_RPMSG) += imx-pcm-rpmsg.o
 snd-soc-eukrea-tlv320-y := eukrea-tlv320.o
 snd-soc-imx-es8328-y := imx-es8328.o
 snd-soc-imx-sgtl5000-y := imx-sgtl5000.o
-snd-soc-imx-spdif-y := imx-spdif.o
 snd-soc-imx-audmix-y := imx-audmix.o
 snd-soc-imx-hdmi-y := imx-hdmi.o
 snd-soc-imx-rpmsg-y := imx-rpmsg.o
@@ -76,7 +75,6 @@ snd-soc-imx-card-y := imx-card.o
 obj-$(CONFIG_SND_SOC_EUKREA_TLV320) += snd-soc-eukrea-tlv320.o
 obj-$(CONFIG_SND_SOC_IMX_ES8328) += snd-soc-imx-es8328.o
 obj-$(CONFIG_SND_SOC_IMX_SGTL5000) += snd-soc-imx-sgtl5000.o
-obj-$(CONFIG_SND_SOC_IMX_SPDIF) += snd-soc-imx-spdif.o
 obj-$(CONFIG_SND_SOC_IMX_AUDMIX) += snd-soc-imx-audmix.o
 obj-$(CONFIG_SND_SOC_IMX_HDMI) += snd-soc-imx-hdmi.o
 obj-$(CONFIG_SND_SOC_IMX_RPMSG) += snd-soc-imx-rpmsg.o

sound/soc/fsl/fsl-asoc-card.c

@@ -99,7 +99,7 @@ struct fsl_asoc_card_priv {
 	struct simple_util_jack hp_jack;
 	struct simple_util_jack mic_jack;
 	struct platform_device *pdev;
-	struct codec_priv codec_priv;
+	struct codec_priv codec_priv[2];
 	struct cpu_priv cpu_priv;
 	struct snd_soc_card card;
 	u8 streams;
@@ -172,10 +172,12 @@ static int fsl_asoc_card_hw_params(struct snd_pcm_substream *substream,
 	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 	struct fsl_asoc_card_priv *priv = snd_soc_card_get_drvdata(rtd->card);
 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
-	struct codec_priv *codec_priv = &priv->codec_priv;
+	struct codec_priv *codec_priv;
+	struct snd_soc_dai *codec_dai;
 	struct cpu_priv *cpu_priv = &priv->cpu_priv;
 	struct device *dev = rtd->card->dev;
 	unsigned int pll_out;
+	int codec_idx;
 	int ret;
 
 	priv->sample_rate = params_rate(params);
@@ -208,28 +210,32 @@ static int fsl_asoc_card_hw_params(struct snd_pcm_substream *substream,
 	}
 
 	/* Specific configuration for PLL */
-	if (codec_priv->pll_id >= 0 && codec_priv->fll_id >= 0) {
-		if (priv->sample_format == SNDRV_PCM_FORMAT_S24_LE)
-			pll_out = priv->sample_rate * 384;
-		else
-			pll_out = priv->sample_rate * 256;
+	for_each_rtd_codec_dais(rtd, codec_idx, codec_dai) {
+		codec_priv = &priv->codec_priv[codec_idx];
 
-		ret = snd_soc_dai_set_pll(snd_soc_rtd_to_codec(rtd, 0),
-					  codec_priv->pll_id,
-					  codec_priv->mclk_id,
-					  codec_priv->mclk_freq, pll_out);
-		if (ret) {
-			dev_err(dev, "failed to start FLL: %d\n", ret);
-			goto fail;
-		}
+		if (codec_priv->pll_id >= 0 && codec_priv->fll_id >= 0) {
+			if (priv->sample_format == SNDRV_PCM_FORMAT_S24_LE)
+				pll_out = priv->sample_rate * 384;
+			else
+				pll_out = priv->sample_rate * 256;
 
-		ret = snd_soc_dai_set_sysclk(snd_soc_rtd_to_codec(rtd, 0),
-					     codec_priv->fll_id,
-					     pll_out, SND_SOC_CLOCK_IN);
+			ret = snd_soc_dai_set_pll(codec_dai,
+						codec_priv->pll_id,
+						codec_priv->mclk_id,
+						codec_priv->mclk_freq, pll_out);
+			if (ret) {
+				dev_err(dev, "failed to start FLL: %d\n", ret);
+				goto fail;
+			}
 
-		if (ret && ret != -ENOTSUPP) {
-			dev_err(dev, "failed to set SYSCLK: %d\n", ret);
-			goto fail;
+			ret = snd_soc_dai_set_sysclk(codec_dai,
+						codec_priv->fll_id,
+						pll_out, SND_SOC_CLOCK_IN);
+
+			if (ret && ret != -ENOTSUPP) {
+				dev_err(dev, "failed to set SYSCLK: %d\n", ret);
+				goto fail;
+			}
 		}
 	}
 
@@ -244,28 +250,34 @@ static int fsl_asoc_card_hw_free(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 	struct fsl_asoc_card_priv *priv = snd_soc_card_get_drvdata(rtd->card);
-	struct codec_priv *codec_priv = &priv->codec_priv;
+	struct codec_priv *codec_priv;
+	struct snd_soc_dai *codec_dai;
 	struct device *dev = rtd->card->dev;
+	int codec_idx;
 	int ret;
 
 	priv->streams &= ~BIT(substream->stream);
 
-	if (!priv->streams && codec_priv->pll_id >= 0 && codec_priv->fll_id >= 0) {
-		/* Force freq to be free_freq to avoid error message in codec */
-		ret = snd_soc_dai_set_sysclk(snd_soc_rtd_to_codec(rtd, 0),
-					     codec_priv->mclk_id,
-					     codec_priv->free_freq,
-					     SND_SOC_CLOCK_IN);
-		if (ret) {
-			dev_err(dev, "failed to switch away from FLL: %d\n", ret);
-			return ret;
-		}
+	for_each_rtd_codec_dais(rtd, codec_idx, codec_dai) {
+		codec_priv = &priv->codec_priv[codec_idx];
 
-		ret = snd_soc_dai_set_pll(snd_soc_rtd_to_codec(rtd, 0),
-					  codec_priv->pll_id, 0, 0, 0);
-		if (ret && ret != -ENOTSUPP) {
-			dev_err(dev, "failed to stop FLL: %d\n", ret);
-			return ret;
+		if (!priv->streams && codec_priv->pll_id >= 0 && codec_priv->fll_id >= 0) {
+			/* Force freq to be free_freq to avoid error message in codec */
+			ret = snd_soc_dai_set_sysclk(codec_dai,
+						codec_priv->mclk_id,
+						codec_priv->free_freq,
+						SND_SOC_CLOCK_IN);
+			if (ret) {
+				dev_err(dev, "failed to switch away from FLL: %d\n", ret);
+				return ret;
+			}
+
+			ret = snd_soc_dai_set_pll(codec_dai,
+						codec_priv->pll_id, 0, 0, 0);
+			if (ret && ret != -ENOTSUPP) {
+				dev_err(dev, "failed to stop FLL: %d\n", ret);
+				return ret;
+			}
 		}
 	}
 
@@ -296,7 +308,7 @@ static int be_hw_params_fixup(struct snd_soc_pcm_runtime *rtd,
 
 SND_SOC_DAILINK_DEFS(hifi,
 	DAILINK_COMP_ARRAY(COMP_EMPTY()),
-	DAILINK_COMP_ARRAY(COMP_EMPTY()),
+	DAILINK_COMP_ARRAY(COMP_EMPTY(), COMP_EMPTY()),
 	DAILINK_COMP_ARRAY(COMP_EMPTY()));
 
 SND_SOC_DAILINK_DEFS(hifi_fe,
@@ -306,7 +318,7 @@ SND_SOC_DAILINK_DEFS(hifi_fe,
 
 SND_SOC_DAILINK_DEFS(hifi_be,
 	DAILINK_COMP_ARRAY(COMP_EMPTY()),
-	DAILINK_COMP_ARRAY(COMP_EMPTY()));
+	DAILINK_COMP_ARRAY(COMP_EMPTY(), COMP_EMPTY()));
 
 static const struct snd_soc_dai_link fsl_asoc_card_dai[] = {
 	/* Default ASoC DAI Link*/
@@ -465,6 +477,75 @@ static int fsl_asoc_card_audmux_init(struct device_node *np,
 	return 0;
 }
 
+static int fsl_asoc_card_spdif_init(struct device_node *codec_np[],
+				    struct device_node *cpu_np,
+				    const char *codec_dai_name[],
+				    struct fsl_asoc_card_priv *priv)
+{
+	struct device *dev = &priv->pdev->dev;
+	struct device_node *np = dev->of_node;
+
+	if (!of_node_name_eq(cpu_np, "spdif")) {
+		dev_err(dev, "CPU phandle invalid, should be an SPDIF device\n");
+		return -EINVAL;
+	}
+
+	priv->dai_link[0].playback_only = true;
+	priv->dai_link[0].capture_only = true;
+
+	for (int i = 0; i < 2; i++) {
+		if (!codec_np[i])
+			break;
+
+		if (of_device_is_compatible(codec_np[i], "linux,spdif-dit")) {
+			priv->dai_link[0].capture_only = false;
+			codec_dai_name[i] = "dit-hifi";
+		} else if (of_device_is_compatible(codec_np[i], "linux,spdif-dir")) {
+			priv->dai_link[0].playback_only = false;
+			codec_dai_name[i] = "dir-hifi";
+		}
+	}
+
+	// Old SPDIF DT binding
+	if (!codec_np[0]) {
+		codec_dai_name[0] = snd_soc_dummy_dlc.dai_name;
+		if (of_property_read_bool(np, "spdif-out"))
+			priv->dai_link[0].capture_only = false;
+		if (of_property_read_bool(np, "spdif-in"))
+			priv->dai_link[0].playback_only = false;
+	}
+
+	if (priv->dai_link[0].playback_only && priv->dai_link[0].capture_only) {
+		dev_err(dev, "no enabled S/PDIF DAI link\n");
+		return -EINVAL;
+	}
+
+	if (priv->dai_link[0].playback_only) {
+		priv->dai_link[1].dpcm_capture = false;
+		priv->dai_link[2].dpcm_capture = false;
+		priv->card.dapm_routes = audio_map_tx;
+		priv->card.num_dapm_routes = ARRAY_SIZE(audio_map_tx);
+	} else if (priv->dai_link[0].capture_only) {
+		priv->dai_link[1].dpcm_playback = false;
+		priv->dai_link[2].dpcm_playback = false;
+		priv->card.dapm_routes = audio_map_rx;
+		priv->card.num_dapm_routes = ARRAY_SIZE(audio_map_rx);
+	}
+
+	// No DAPM routes with old bindings and dummy codec
+	if (!codec_np[0]) {
+		priv->card.dapm_routes = NULL;
+		priv->card.num_dapm_routes = 0;
+	}
+
+	if (codec_np[0] && codec_np[1]) {
+		priv->dai_link[0].num_codecs = 2;
+		priv->dai_link[2].num_codecs = 2;
+	}
+
+	return 0;
+}
+
 static int hp_jack_event(struct notifier_block *nb, unsigned long event,
 			 void *data)
 {
@@ -504,9 +585,10 @@ static int fsl_asoc_card_late_probe(struct snd_soc_card *card)
 	struct fsl_asoc_card_priv *priv = snd_soc_card_get_drvdata(card);
 	struct snd_soc_pcm_runtime *rtd = list_first_entry(
 			&card->rtd_list, struct snd_soc_pcm_runtime, list);
-	struct snd_soc_dai *codec_dai = snd_soc_rtd_to_codec(rtd, 0);
-	struct codec_priv *codec_priv = &priv->codec_priv;
+	struct snd_soc_dai *codec_dai;
+	struct codec_priv *codec_priv;
 	struct device *dev = card->dev;
+	int codec_idx;
 	int ret;
 
 	if (fsl_asoc_card_is_ac97(priv)) {
@@ -526,32 +608,39 @@ static int fsl_asoc_card_late_probe(struct snd_soc_card *card)
 		return 0;
 	}
 
-	ret = snd_soc_dai_set_sysclk(codec_dai, codec_priv->mclk_id,
-				     codec_priv->mclk_freq, SND_SOC_CLOCK_IN);
-	if (ret && ret != -ENOTSUPP) {
-		dev_err(dev, "failed to set sysclk in %s\n", __func__);
-		return ret;
-	}
+	for_each_rtd_codec_dais(rtd, codec_idx, codec_dai) {
+		codec_priv = &priv->codec_priv[codec_idx];
 
-	if (!IS_ERR_OR_NULL(codec_priv->mclk))
-		clk_prepare_enable(codec_priv->mclk);
+		ret = snd_soc_dai_set_sysclk(codec_dai, codec_priv->mclk_id,
+					codec_priv->mclk_freq, SND_SOC_CLOCK_IN);
+		if (ret && ret != -ENOTSUPP) {
+			dev_err(dev, "failed to set sysclk in %s\n", __func__);
+			return ret;
+		}
+
+		if (!IS_ERR_OR_NULL(codec_priv->mclk))
+			clk_prepare_enable(codec_priv->mclk);
+	}
 
 	return 0;
 }
 
 static int fsl_asoc_card_probe(struct platform_device *pdev)
 {
-	struct device_node *cpu_np, *codec_np, *asrc_np;
+	struct device_node *cpu_np, *asrc_np;
+	struct snd_soc_dai_link_component *codec_comp;
+	struct device_node *codec_np[2];
 	struct device_node *np = pdev->dev.of_node;
 	struct platform_device *asrc_pdev = NULL;
 	struct device_node *bitclkprovider = NULL;
 	struct device_node *frameprovider = NULL;
 	struct platform_device *cpu_pdev;
 	struct fsl_asoc_card_priv *priv;
-	struct device *codec_dev = NULL;
-	const char *codec_dai_name;
-	const char *codec_dev_name;
+	struct device *codec_dev[2] = { NULL, NULL };
+	const char *codec_dai_name[2];
+	const char *codec_dev_name[2];
 	u32 asrc_fmt = 0;
+	int codec_idx;
 	u32 width;
 	int ret;
 
@@ -562,9 +651,11 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 	priv->pdev = pdev;
 
 	cpu_np = of_parse_phandle(np, "audio-cpu", 0);
-	/* Give a chance to old DT binding */
+	/* Give a chance to old DT bindings */
 	if (!cpu_np)
 		cpu_np = of_parse_phandle(np, "ssi-controller", 0);
+	if (!cpu_np)
+		cpu_np = of_parse_phandle(np, "spdif-controller", 0);
 	if (!cpu_np) {
 		dev_err(&pdev->dev, "CPU phandle missing or invalid\n");
 		ret = -EINVAL;
@@ -578,21 +669,25 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 		goto fail;
 	}
 
-	codec_np = of_parse_phandle(np, "audio-codec", 0);
-	if (codec_np) {
-		struct platform_device *codec_pdev;
-		struct i2c_client *codec_i2c;
+	codec_np[0] = of_parse_phandle(np, "audio-codec", 0);
+	codec_np[1] = of_parse_phandle(np, "audio-codec", 1);
 
-		codec_i2c = of_find_i2c_device_by_node(codec_np);
-		if (codec_i2c) {
-			codec_dev = &codec_i2c->dev;
-			codec_dev_name = codec_i2c->name;
-		}
-		if (!codec_dev) {
-			codec_pdev = of_find_device_by_node(codec_np);
-			if (codec_pdev) {
-				codec_dev = &codec_pdev->dev;
-				codec_dev_name = codec_pdev->name;
+	for (codec_idx = 0; codec_idx < 2; codec_idx++) {
+		if (codec_np[codec_idx]) {
+			struct platform_device *codec_pdev;
+			struct i2c_client *codec_i2c;
+
+			codec_i2c = of_find_i2c_device_by_node(codec_np[codec_idx]);
+			if (codec_i2c) {
+				codec_dev[codec_idx] = &codec_i2c->dev;
+				codec_dev_name[codec_idx] = codec_i2c->name;
+			}
+			if (!codec_dev[codec_idx]) {
+				codec_pdev = of_find_device_by_node(codec_np[codec_idx]);
+				if (codec_pdev) {
+					codec_dev[codec_idx] = &codec_pdev->dev;
+					codec_dev_name[codec_idx] = codec_pdev->name;
+				}
 			}
 		}
 	}
@@ -602,12 +697,14 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 		asrc_pdev = of_find_device_by_node(asrc_np);
 
 	/* Get the MCLK rate only, and leave it controlled by CODEC drivers */
-	if (codec_dev) {
-		struct clk *codec_clk = clk_get(codec_dev, NULL);
+	for (codec_idx = 0; codec_idx < 2; codec_idx++) {
+		if (codec_dev[codec_idx]) {
+			struct clk *codec_clk = clk_get(codec_dev[codec_idx], NULL);
 
-		if (!IS_ERR(codec_clk)) {
-			priv->codec_priv.mclk_freq = clk_get_rate(codec_clk);
-			clk_put(codec_clk);
+			if (!IS_ERR(codec_clk)) {
+				priv->codec_priv[codec_idx].mclk_freq = clk_get_rate(codec_clk);
+				clk_put(codec_clk);
+			}
 		}
 	}
 
@@ -620,36 +717,40 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 
 	memcpy(priv->dai_link, fsl_asoc_card_dai,
 	       sizeof(struct snd_soc_dai_link) * ARRAY_SIZE(priv->dai_link));
+	priv->dai_link[0].num_codecs = 1;
+	priv->dai_link[2].num_codecs = 1;
 
 	priv->card.dapm_routes = audio_map;
 	priv->card.num_dapm_routes = ARRAY_SIZE(audio_map);
 	priv->card.driver_name = DRIVER_NAME;
 
-	priv->codec_priv.fll_id = -1;
-	priv->codec_priv.pll_id = -1;
+	for (codec_idx = 0; codec_idx < 2; codec_idx++) {
+		priv->codec_priv[codec_idx].fll_id = -1;
+		priv->codec_priv[codec_idx].pll_id = -1;
+	}
 
 	/* Diversify the card configurations */
 	if (of_device_is_compatible(np, "fsl,imx-audio-cs42888")) {
-		codec_dai_name = "cs42888";
-		priv->cpu_priv.sysclk_freq[TX] = priv->codec_priv.mclk_freq;
-		priv->cpu_priv.sysclk_freq[RX] = priv->codec_priv.mclk_freq;
+		codec_dai_name[0] = "cs42888";
+		priv->cpu_priv.sysclk_freq[TX] = priv->codec_priv[0].mclk_freq;
+		priv->cpu_priv.sysclk_freq[RX] = priv->codec_priv[0].mclk_freq;
 		priv->cpu_priv.sysclk_dir[TX] = SND_SOC_CLOCK_OUT;
 		priv->cpu_priv.sysclk_dir[RX] = SND_SOC_CLOCK_OUT;
 		priv->cpu_priv.slot_width = 32;
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBC_CFC;
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-cs427x")) {
-		codec_dai_name = "cs4271-hifi";
-		priv->codec_priv.mclk_id = CS427x_SYSCLK_MCLK;
+		codec_dai_name[0] = "cs4271-hifi";
+		priv->codec_priv[0].mclk_id = CS427x_SYSCLK_MCLK;
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBP_CFP;
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-sgtl5000")) {
-		codec_dai_name = "sgtl5000";
-		priv->codec_priv.mclk_id = SGTL5000_SYSCLK;
+		codec_dai_name[0] = "sgtl5000";
+		priv->codec_priv[0].mclk_id = SGTL5000_SYSCLK;
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBP_CFP;
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-tlv320aic32x4")) {
-		codec_dai_name = "tlv320aic32x4-hifi";
+		codec_dai_name[0] = "tlv320aic32x4-hifi";
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBP_CFP;
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-tlv320aic31xx")) {
-		codec_dai_name = "tlv320dac31xx-hifi";
+		codec_dai_name[0] = "tlv320dac31xx-hifi";
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBS_CFS;
 		priv->dai_link[1].dpcm_capture = 0;
 		priv->dai_link[2].dpcm_capture = 0;
@@ -658,23 +759,23 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 		priv->card.dapm_routes = audio_map_tx;
 		priv->card.num_dapm_routes = ARRAY_SIZE(audio_map_tx);
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-wm8962")) {
-		codec_dai_name = "wm8962";
-		priv->codec_priv.mclk_id = WM8962_SYSCLK_MCLK;
-		priv->codec_priv.fll_id = WM8962_SYSCLK_FLL;
-		priv->codec_priv.pll_id = WM8962_FLL;
+		codec_dai_name[0] = "wm8962";
+		priv->codec_priv[0].mclk_id = WM8962_SYSCLK_MCLK;
+		priv->codec_priv[0].fll_id = WM8962_SYSCLK_FLL;
+		priv->codec_priv[0].pll_id = WM8962_FLL;
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBP_CFP;
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-wm8960")) {
-		codec_dai_name = "wm8960-hifi";
-		priv->codec_priv.fll_id = WM8960_SYSCLK_AUTO;
-		priv->codec_priv.pll_id = WM8960_SYSCLK_AUTO;
+		codec_dai_name[0] = "wm8960-hifi";
+		priv->codec_priv[0].fll_id = WM8960_SYSCLK_AUTO;
+		priv->codec_priv[0].pll_id = WM8960_SYSCLK_AUTO;
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBP_CFP;
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-ac97")) {
-		codec_dai_name = "ac97-hifi";
+		codec_dai_name[0] = "ac97-hifi";
 		priv->dai_fmt = SND_SOC_DAIFMT_AC97;
 		priv->card.dapm_routes = audio_map_ac97;
 		priv->card.num_dapm_routes = ARRAY_SIZE(audio_map_ac97);
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-mqs")) {
-		codec_dai_name = "fsl-mqs-dai";
+		codec_dai_name[0] = "fsl-mqs-dai";
 		priv->dai_fmt = SND_SOC_DAIFMT_LEFT_J |
 				SND_SOC_DAIFMT_CBC_CFC |
 				SND_SOC_DAIFMT_NB_NF;
@@ -683,7 +784,7 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 		priv->card.dapm_routes = audio_map_tx;
 		priv->card.num_dapm_routes = ARRAY_SIZE(audio_map_tx);
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-wm8524")) {
-		codec_dai_name = "wm8524-hifi";
+		codec_dai_name[0] = "wm8524-hifi";
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBC_CFC;
 		priv->dai_link[1].dpcm_capture = 0;
 		priv->dai_link[2].dpcm_capture = 0;
@@ -691,33 +792,37 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 		priv->card.dapm_routes = audio_map_tx;
 		priv->card.num_dapm_routes = ARRAY_SIZE(audio_map_tx);
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-si476x")) {
-		codec_dai_name = "si476x-codec";
+		codec_dai_name[0] = "si476x-codec";
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBC_CFC;
 		priv->card.dapm_routes = audio_map_rx;
 		priv->card.num_dapm_routes = ARRAY_SIZE(audio_map_rx);
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-wm8958")) {
-		codec_dai_name = "wm8994-aif1";
+		codec_dai_name[0] = "wm8994-aif1";
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBP_CFP;
-		priv->codec_priv.mclk_id = WM8994_FLL_SRC_MCLK1;
-		priv->codec_priv.fll_id = WM8994_SYSCLK_FLL1;
-		priv->codec_priv.pll_id = WM8994_FLL1;
-		priv->codec_priv.free_freq = priv->codec_priv.mclk_freq;
+		priv->codec_priv[0].mclk_id = WM8994_FLL_SRC_MCLK1;
+		priv->codec_priv[0].fll_id = WM8994_SYSCLK_FLL1;
+		priv->codec_priv[0].pll_id = WM8994_FLL1;
+		priv->codec_priv[0].free_freq = priv->codec_priv[0].mclk_freq;
 		priv->card.dapm_routes = NULL;
 		priv->card.num_dapm_routes = 0;
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-nau8822")) {
-		codec_dai_name = "nau8822-hifi";
-		priv->codec_priv.mclk_id = NAU8822_CLK_MCLK;
-		priv->codec_priv.fll_id = NAU8822_CLK_PLL;
-		priv->codec_priv.pll_id = NAU8822_CLK_PLL;
+		codec_dai_name[0] = "nau8822-hifi";
+		priv->codec_priv[0].mclk_id = NAU8822_CLK_MCLK;
+		priv->codec_priv[0].fll_id = NAU8822_CLK_PLL;
+		priv->codec_priv[0].pll_id = NAU8822_CLK_PLL;
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBM_CFM;
-		if (codec_dev)
-			priv->codec_priv.mclk = devm_clk_get(codec_dev, NULL);
+		if (codec_dev[0])
+			priv->codec_priv[0].mclk = devm_clk_get(codec_dev[0], NULL);
 	} else if (of_device_is_compatible(np, "fsl,imx-audio-wm8904")) {
-		codec_dai_name = "wm8904-hifi";
-		priv->codec_priv.mclk_id = WM8904_FLL_MCLK;
-		priv->codec_priv.fll_id = WM8904_CLK_FLL;
-		priv->codec_priv.pll_id = WM8904_FLL_MCLK;
+		codec_dai_name[0] = "wm8904-hifi";
+		priv->codec_priv[0].mclk_id = WM8904_FLL_MCLK;
+		priv->codec_priv[0].fll_id = WM8904_CLK_FLL;
+		priv->codec_priv[0].pll_id = WM8904_FLL_MCLK;
 		priv->dai_fmt |= SND_SOC_DAIFMT_CBP_CFP;
+	} else if (of_device_is_compatible(np, "fsl,imx-audio-spdif")) {
+		ret = fsl_asoc_card_spdif_init(codec_np, cpu_np, codec_dai_name, priv);
+		if (ret)
+			goto asrc_fail;
 	} else {
 		dev_err(&pdev->dev, "unknown Device Tree compatible\n");
 		ret = -EINVAL;
@@ -728,18 +833,30 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 	 * Allow setting mclk-id from the device-tree node. Otherwise, the
 	 * default value for each card configuration is used.
 	 */
-	of_property_read_u32(np, "mclk-id", &priv->codec_priv.mclk_id);
+	for_each_link_codecs((&(priv->dai_link[0])), codec_idx, codec_comp) {
+		of_property_read_u32_index(np, "mclk-id", codec_idx,
+					&priv->codec_priv[codec_idx].mclk_id);
+	}
 
 	/* Format info from DT is optional. */
 	snd_soc_daifmt_parse_clock_provider_as_phandle(np, NULL, &bitclkprovider, &frameprovider);
 	if (bitclkprovider || frameprovider) {
 		unsigned int daifmt = snd_soc_daifmt_parse_format(np, NULL);
+		bool codec_bitclkprovider = false;
+		bool codec_frameprovider = false;
+
+		for_each_link_codecs((&(priv->dai_link[0])), codec_idx, codec_comp) {
+			if (bitclkprovider && codec_np[codec_idx] == bitclkprovider)
+				codec_bitclkprovider = true;
+			if (frameprovider && codec_np[codec_idx] == frameprovider)
+				codec_frameprovider = true;
+		}
 
-		if (codec_np == bitclkprovider)
-			daifmt |= (codec_np == frameprovider) ?
+		if (codec_bitclkprovider)
+			daifmt |= (codec_frameprovider) ?
 				SND_SOC_DAIFMT_CBP_CFP : SND_SOC_DAIFMT_CBP_CFC;
 		else
-			daifmt |= (codec_np == frameprovider) ?
+			daifmt |= (codec_frameprovider) ?
 				SND_SOC_DAIFMT_CBC_CFP : SND_SOC_DAIFMT_CBC_CFC;
 
 		/* Override dai_fmt with value from DT */
@@ -755,7 +872,8 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 	of_node_put(bitclkprovider);
 	of_node_put(frameprovider);
 
-	if (!fsl_asoc_card_is_ac97(priv) && !codec_dev) {
+	if (!fsl_asoc_card_is_ac97(priv) && !codec_dev[0]
+	    && codec_dai_name[0] != snd_soc_dummy_dlc.dai_name) {
 		dev_dbg(&pdev->dev, "failed to find codec device\n");
 		ret = -EPROBE_DEFER;
 		goto asrc_fail;
@@ -794,7 +912,7 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 	ret = snd_soc_of_parse_card_name(&priv->card, "model");
 	if (ret) {
 		snprintf(priv->name, sizeof(priv->name), "%s-audio",
-			 fsl_asoc_card_is_ac97(priv) ? "ac97" : codec_dev_name);
+			 fsl_asoc_card_is_ac97(priv) ? "ac97" : codec_dev_name[0]);
 		priv->card.name = priv->name;
 	}
 	priv->card.dai_link = priv->dai_link;
@@ -816,11 +934,19 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 
 	/* Normal DAI Link */
 	priv->dai_link[0].cpus->of_node = cpu_np;
-	priv->dai_link[0].codecs->dai_name = codec_dai_name;
+	for_each_link_codecs((&(priv->dai_link[0])), codec_idx, codec_comp) {
+		codec_comp->dai_name = codec_dai_name[codec_idx];
+	}
+
+	// Old SPDIF DT binding support
+	if (codec_dai_name[0] == snd_soc_dummy_dlc.dai_name)
+		priv->dai_link[0].codecs[0].name = snd_soc_dummy_dlc.name;
 
-	if (!fsl_asoc_card_is_ac97(priv))
-		priv->dai_link[0].codecs->of_node = codec_np;
-	else {
+	if (!fsl_asoc_card_is_ac97(priv)) {
+		for_each_link_codecs((&(priv->dai_link[0])), codec_idx, codec_comp) {
+			codec_comp->of_node = codec_np[codec_idx];
+		}
+	} else {
 		u32 idx;
 
 		ret = of_property_read_u32(cpu_np, "cell-index", &idx);
@@ -830,11 +956,11 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 			goto asrc_fail;
 		}
 
-		priv->dai_link[0].codecs->name =
+		priv->dai_link[0].codecs[0].name =
 				devm_kasprintf(&pdev->dev, GFP_KERNEL,
 					       "ac97-codec.%u",
 					       (unsigned int)idx);
-		if (!priv->dai_link[0].codecs->name) {
+		if (!priv->dai_link[0].codecs[0].name) {
 			ret = -ENOMEM;
 			goto asrc_fail;
 		}
@@ -848,10 +974,11 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 		/* DPCM DAI Links only if ASRC exists */
 		priv->dai_link[1].cpus->of_node = asrc_np;
 		priv->dai_link[1].platforms->of_node = asrc_np;
-		priv->dai_link[2].codecs->dai_name = codec_dai_name;
-		priv->dai_link[2].codecs->of_node = codec_np;
-		priv->dai_link[2].codecs->name =
-				priv->dai_link[0].codecs->name;
+		for_each_link_codecs((&(priv->dai_link[2])), codec_idx, codec_comp) {
+			codec_comp->dai_name = priv->dai_link[0].codecs[codec_idx].dai_name;
+			codec_comp->of_node = priv->dai_link[0].codecs[codec_idx].of_node;
+			codec_comp->name = priv->dai_link[0].codecs[codec_idx].name;
+		}
 		priv->dai_link[2].cpus->of_node = cpu_np;
 		priv->dai_link[2].dai_fmt = priv->dai_fmt;
 		priv->card.num_links = 3;
@@ -921,7 +1048,8 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 
 asrc_fail:
 	of_node_put(asrc_np);
-	of_node_put(codec_np);
+	of_node_put(codec_np[0]);
+	of_node_put(codec_np[1]);
 	put_device(&cpu_pdev->dev);
 fail:
 	of_node_put(cpu_np);
@@ -944,6 +1072,7 @@ static const struct of_device_id fsl_asoc_card_dt_ids[] = {
 	{ .compatible = "fsl,imx-audio-wm8958", },
 	{ .compatible = "fsl,imx-audio-nau8822", },
 	{ .compatible = "fsl,imx-audio-wm8904", },
+	{ .compatible = "fsl,imx-audio-spdif", },
 	{}
 };
 MODULE_DEVICE_TABLE(of, fsl_asoc_card_dt_ids);

sound/soc/fsl/imx-spdif.c

-// SPDX-License-Identifier: GPL-2.0+
-//
-// Copyright (C) 2013 Freescale Semiconductor, Inc.
-
-#include <linux/module.h>
-#include <linux/of_platform.h>
-#include <sound/soc.h>
-
-struct imx_spdif_data {
-	struct snd_soc_dai_link dai;
-	struct snd_soc_card card;
-};
-
-static int imx_spdif_audio_probe(struct platform_device *pdev)
-{
-	struct device_node *spdif_np, *np = pdev->dev.of_node;
-	struct imx_spdif_data *data;
-	struct snd_soc_dai_link_component *comp;
-	int ret = 0;
-
-	spdif_np = of_parse_phandle(np, "spdif-controller", 0);
-	if (!spdif_np) {
-		dev_err(&pdev->dev, "failed to find spdif-controller\n");
-		ret = -EINVAL;
-		goto end;
-	}
-
-	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-	comp = devm_kzalloc(&pdev->dev, sizeof(*comp), GFP_KERNEL);
-	if (!data || !comp) {
-		ret = -ENOMEM;
-		goto end;
-	}
-
-	/*
-	 * CPU == Platform
-	 * platform is using soc-generic-dmaengine-pcm
-	 */
-	data->dai.cpus		=
-	data->dai.platforms	= comp;
-	data->dai.codecs	= &snd_soc_dummy_dlc;
-
-	data->dai.num_cpus	= 1;
-	data->dai.num_codecs	= 1;
-	data->dai.num_platforms	= 1;
-
-	data->dai.name = "S/PDIF PCM";
-	data->dai.stream_name = "S/PDIF PCM";
-	data->dai.cpus->of_node = spdif_np;
-	data->dai.playback_only = true;
-	data->dai.capture_only = true;
-
-	if (of_property_read_bool(np, "spdif-out"))
-		data->dai.capture_only = false;
-
-	if (of_property_read_bool(np, "spdif-in"))
-		data->dai.playback_only = false;
-
-	if (data->dai.playback_only && data->dai.capture_only) {
-		dev_err(&pdev->dev, "no enabled S/PDIF DAI link\n");
-		goto end;
-	}
-
-	data->card.dev = &pdev->dev;
-	data->card.dai_link = &data->dai;
-	data->card.num_links = 1;
-	data->card.owner = THIS_MODULE;
-
-	ret = snd_soc_of_parse_card_name(&data->card, "model");
-	if (ret)
-		goto end;
-
-	ret = devm_snd_soc_register_card(&pdev->dev, &data->card);
-	if (ret)
-		dev_err_probe(&pdev->dev, ret, "snd_soc_register_card failed\n");
-
-end:
-	of_node_put(spdif_np);
-
-	return ret;
-}
-
-static const struct of_device_id imx_spdif_dt_ids[] = {
-	{ .compatible = "fsl,imx-audio-spdif", },
-	{ /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, imx_spdif_dt_ids);
-
-static struct platform_driver imx_spdif_driver = {
-	.driver = {
-		.name = "imx-spdif",
-		.pm = &snd_soc_pm_ops,
-		.of_match_table = imx_spdif_dt_ids,
-	},
-	.probe = imx_spdif_audio_probe,
-};
-
-module_platform_driver(imx_spdif_driver);
-
-MODULE_AUTHOR("Freescale Semiconductor, Inc.");
-MODULE_DESCRIPTION("Freescale i.MX S/PDIF machine driver");
-MODULE_LICENSE("GPL v2");
-MODULE_ALIAS("platform:imx-spdif");