ASoC: sof-function-topology-lib: add echo reference topology support

The Loopback_Virtual DAI link is for echo reference. We can load the
corresponding echo reference topology if the Loopback_Virtual DAI link
is created.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>

Author: bardliao

sound/soc/intel/common/sof-function-topology-lib.c

@@ -19,6 +19,7 @@ enum tplg_device_id {
 	TPLG_DEVICE_SDCA_MIC,
 	TPLG_DEVICE_INTEL_PCH_DMIC,
 	TPLG_DEVICE_HDMI,
+	TPLG_DEVICE_LOOPBACK_VIRTUAL,
 	TPLG_DEVICE_MAX
 };
 
@@ -54,6 +55,7 @@ int sof_sdw_get_tplg_files(struct snd_soc_card *card, const struct snd_soc_acpi_
 		if (strstr(dai_link->name, "SimpleJack")) {
 			tplg_dev = TPLG_DEVICE_SDCA_JACK;
 			tplg_dev_name = "sdca-jack";
+
 		} else if (strstr(dai_link->name, "SmartAmp")) {
 			tplg_dev = TPLG_DEVICE_SDCA_AMP;
 			tplg_dev_name = devm_kasprintf(card->dev, GFP_KERNEL,
@@ -81,7 +83,29 @@ int sof_sdw_get_tplg_files(struct snd_soc_card *card, const struct snd_soc_acpi_
 		} else if (strstr(dai_link->name, "iDisp")) {
 			tplg_dev = TPLG_DEVICE_HDMI;
 			tplg_dev_name = "hdmi-pcm5";
-
+		} else if (strstr(dai_link->name, "Loopback_Virtual")) {
+			/*
+			 * Loopback_Virtual is always the last DAI link, that's why we can check
+			 * tplg_mask to know whether the jack or amp DAI link exists, and select
+			 * the echo reference topology accordingly.
+			 */
+			switch (tplg_mask & (BIT(TPLG_DEVICE_SDCA_JACK) | BIT(TPLG_DEVICE_SDCA_AMP))) {
+			case BIT(TPLG_DEVICE_SDCA_JACK):
+				tplg_dev_name = "sdca-jack-ref";
+				break;
+			case BIT(TPLG_DEVICE_SDCA_AMP):
+				tplg_dev_name = "sdca-amp-ref";
+				break;
+			case (BIT(TPLG_DEVICE_SDCA_JACK) | BIT(TPLG_DEVICE_SDCA_AMP)):
+				tplg_dev_name = "sdca-jack-amp-ref";
+				break;
+			default: /* No jack or amp */
+				dev_dbg(card->dev,
+					"tplg_mask %#lx, No echo referrence is required\n",
+					tplg_mask);
+				continue;
+			}
+			tplg_dev = TPLG_DEVICE_LOOPBACK_VIRTUAL;
 		} else {
 			/* The dai link is not supported by separated tplg yet */
 			dev_dbg(card->dev,
@@ -109,6 +133,11 @@ int sof_sdw_get_tplg_files(struct snd_soc_card *card, const struct snd_soc_acpi_
 								 prefix, platform,
 								 tplg_dev_name, dai_link->id);
 			break;
+		case TPLG_DEVICE_LOOPBACK_VIRTUAL:
+			(*tplg_files)[tplg_num] = devm_kasprintf(card->dev, GFP_KERNEL,
+								 "%s/sof-%s.tplg",
+								 prefix, tplg_dev_name);
+			break;
 		default:
 			(*tplg_files)[tplg_num] = devm_kasprintf(card->dev, GFP_KERNEL,
 								 "%s/sof-%s-id%d.tplg",