ASoC: mediatek: common: add soundcard driver common code

Add common code to support of_node of codec parsing, so codec phandle
can be assigned by sound-dai in dts.
Signed-off-by: Trevor Wu <trevor.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230116034131.23943-12-trevor.wu@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/mediatek/common/Makefile

 # SPDX-License-Identifier: GPL-2.0
 # platform driver
-snd-soc-mtk-common-objs := mtk-afe-platform-driver.o mtk-afe-fe-dai.o mtk-dsp-sof-common.o
+snd-soc-mtk-common-objs := mtk-afe-platform-driver.o mtk-afe-fe-dai.o mtk-dsp-sof-common.o mtk-soundcard-driver.o
 obj-$(CONFIG_SND_SOC_MEDIATEK) += snd-soc-mtk-common.o
 
 obj-$(CONFIG_SND_SOC_MTK_BTCVSD) += mtk-btcvsd.o

sound/soc/mediatek/common/mtk-soundcard-driver.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * mtk-soundcard-driver.c  --  MediaTek soundcard driver common
+ *
+ * Copyright (c) 2022 MediaTek Inc.
+ * Author: Trevor Wu <trevor.wu@mediatek.com>
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <sound/soc.h>
+
+#include "mtk-soundcard-driver.h"
+
+static int set_card_codec_info(struct snd_soc_card *card,
+			       struct device_node *sub_node,
+			       struct snd_soc_dai_link *dai_link)
+{
+	struct device *dev = card->dev;
+	struct device_node *codec_node;
+	int ret;
+
+	codec_node = of_get_child_by_name(sub_node, "codec");
+	if (!codec_node)
+		return -EINVAL;
+
+	/* set card codec info */
+	ret = snd_soc_of_get_dai_link_codecs(dev, codec_node, dai_link);
+
+	of_node_put(codec_node);
+
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "%s: codec dai not found\n",
+				     dai_link->name);
+
+	return 0;
+}
+
+int parse_dai_link_info(struct snd_soc_card *card)
+{
+	struct device *dev = card->dev;
+	struct device_node *sub_node;
+	struct snd_soc_dai_link *dai_link;
+	const char *dai_link_name;
+	int ret, i;
+
+	/* Loop over all the dai link sub nodes */
+	for_each_available_child_of_node(dev->of_node, sub_node) {
+		if (of_property_read_string(sub_node, "link-name",
+					    &dai_link_name))
+			return -EINVAL;
+
+		for_each_card_prelinks(card, i, dai_link) {
+			if (!strcmp(dai_link_name, dai_link->name))
+				break;
+		}
+
+		if (i >= card->num_links)
+			return -EINVAL;
+
+		ret = set_card_codec_info(card, sub_node, dai_link);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(parse_dai_link_info);
+
+void clean_card_reference(struct snd_soc_card *card)
+{
+	struct snd_soc_dai_link *dai_link;
+	int i;
+
+	/* release codec reference gotten by set_card_codec_info */
+	for_each_card_prelinks(card, i, dai_link)
+		snd_soc_of_put_dai_link_codecs(dai_link);
+}
+EXPORT_SYMBOL_GPL(clean_card_reference);

sound/soc/mediatek/common/mtk-soundcard-driver.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * mtk-soundcard-driver.h  --  MediaTek soundcard driver common definition
+ *
+ * Copyright (c) 2022 MediaTek Inc.
+ * Author: Trevor Wu <trevor.wu@mediatek.com>
+ */
+
+#ifndef _MTK_SOUNDCARD_DRIVER_H_
+#define _MTK_SOUNDCARD_DRIVER_H_
+
+int parse_dai_link_info(struct snd_soc_card *card);
+void clean_card_reference(struct snd_soc_card *card);
+#endif