ASoC: loongson: Add Loongson ASoC Sound Card Support

The Loongson ASoC Sound Card is a general ASoC DAI Link driver that
can be used for Loongson CPU DAI drivers and external CODECs.

The driver supports the use of ACPI table to describe device resources.
On loongson 7axxx platforms, the audio device is an ACPI device.

Signed-off-by: Yingkun Meng <mengyingkun@loongson.cn>
Link: https://lore.kernel.org/r/20230614122240.3402762-1-mengyingkun@loongson.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/loongson/Kconfig

@@ -13,4 +13,14 @@ config SND_SOC_LOONGSON_I2S_PCI
 	  The controller is found in loongson bridge chips or SoCs,
 	  and work as a PCI device.
 
+config SND_SOC_LOONGSON_CARD
+	tristate "Loongson Sound Card Driver"
+	select SND_SOC_LOONGSON_I2S_PCI
+	help
+	  Say Y or M if you want to add support for SoC audio using
+	  loongson I2S controller.
+
+	  The driver add support for ALSA SoC Audio support using
+	  loongson I2S controller.
+
 endmenu

sound/soc/loongson/Makefile

@@ -2,3 +2,7 @@
 #Platform Support
 snd-soc-loongson-i2s-pci-objs := loongson_i2s_pci.o loongson_i2s.o loongson_dma.o
 obj-$(CONFIG_SND_SOC_LOONGSON_I2S_PCI) += snd-soc-loongson-i2s-pci.o
+
+#Machine Support
+snd-soc-loongson-card-objs := loongson_card.o
+obj-$(CONFIG_SND_SOC_LOONGSON_CARD) += snd-soc-loongson-card.o

sound/soc/loongson/loongson_card.c

@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Loongson ASoC Audio Machine driver
+//
+// Copyright (C) 2023 Loongson Technology Corporation Limited
+// Author: Yingkun Meng <mengyingkun@loongson.cn>
+//
+
+#include <linux/module.h>
+#include <sound/soc.h>
+#include <sound/soc-acpi.h>
+#include <linux/acpi.h>
+#include <linux/pci.h>
+#include <sound/pcm_params.h>
+
+static char codec_name[SND_ACPI_I2C_ID_LEN];
+
+struct loongson_card_data {
+	struct snd_soc_card snd_card;
+	unsigned int mclk_fs;
+};
+
+static int loongson_card_hw_params(struct snd_pcm_substream *substream,
+				   struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
+	struct snd_soc_dai *codec_dai = asoc_rtd_to_codec(rtd, 0);
+	struct loongson_card_data *ls_card = snd_soc_card_get_drvdata(rtd->card);
+	int ret, mclk;
+
+	if (ls_card->mclk_fs) {
+		mclk = ls_card->mclk_fs * params_rate(params);
+		ret = snd_soc_dai_set_sysclk(cpu_dai, 0, mclk,
+					     SND_SOC_CLOCK_OUT);
+		if (ret < 0) {
+			dev_err(codec_dai->dev, "cpu_dai clock not set\n");
+			return ret;
+		}
+
+		ret = snd_soc_dai_set_sysclk(codec_dai, 0, mclk,
+					     SND_SOC_CLOCK_IN);
+		if (ret < 0) {
+			dev_err(codec_dai->dev, "codec_dai clock not set\n");
+			return ret;
+		}
+	}
+	return 0;
+}
+
+static const struct snd_soc_ops loongson_ops = {
+	.hw_params = loongson_card_hw_params,
+};
+
+SND_SOC_DAILINK_DEFS(analog,
+	DAILINK_COMP_ARRAY(COMP_CPU("loongson-i2s")),
+	DAILINK_COMP_ARRAY(COMP_EMPTY()),
+	DAILINK_COMP_ARRAY(COMP_EMPTY()));
+
+static struct snd_soc_dai_link loongson_dai_links[] = {
+	{
+		.name = "Loongson Audio Port",
+		.stream_name = "Loongson Audio",
+		.dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_IB_NF
+			| SND_SOC_DAIFMT_CBC_CFC,
+		SND_SOC_DAILINK_REG(analog),
+		.ops = &loongson_ops,
+	},
+};
+
+static int loongson_card_parse_acpi(struct loongson_card_data *data)
+{
+	struct snd_soc_card *card = &data->snd_card;
+	struct fwnode_handle *fwnode = card->dev->fwnode;
+	struct fwnode_reference_args args;
+	const char *codec_dai_name;
+	struct acpi_device *adev;
+	struct device *phy_dev;
+	int ret, i;
+
+	/* fixup platform name based on reference node */
+	memset(&args, 0, sizeof(args));
+	ret = acpi_node_get_property_reference(fwnode, "cpu", 0, &args);
+	if (ACPI_FAILURE(ret) || !is_acpi_device_node(args.fwnode)) {
+		dev_err(card->dev, "No matching phy in ACPI table\n");
+		return ret;
+	}
+	adev = to_acpi_device_node(args.fwnode);
+	phy_dev = acpi_get_first_physical_node(adev);
+	if (!phy_dev)
+		return -EPROBE_DEFER;
+	for (i = 0; i < card->num_links; i++)
+		loongson_dai_links[i].platforms->name = dev_name(phy_dev);
+
+	/* fixup codec name based on reference node */
+	memset(&args, 0, sizeof(args));
+	ret = acpi_node_get_property_reference(fwnode, "codec", 0, &args);
+	if (ACPI_FAILURE(ret) || !is_acpi_device_node(args.fwnode)) {
+		dev_err(card->dev, "No matching phy in ACPI table\n");
+		return ret;
+	}
+	adev = to_acpi_device_node(args.fwnode);
+	snprintf(codec_name, sizeof(codec_name), "i2c-%s", acpi_dev_name(adev));
+	for (i = 0; i < card->num_links; i++)
+		loongson_dai_links[i].codecs->name = codec_name;
+
+	device_property_read_string(card->dev, "codec-dai-name",
+				    &codec_dai_name);
+	for (i = 0; i < card->num_links; i++)
+		loongson_dai_links[i].codecs->dai_name = codec_dai_name;
+
+	return 0;
+}
+
+static int loongson_card_parse_of(struct loongson_card_data *data)
+{
+	const char *cpu_dai_name, *codec_dai_name;
+	struct device_node *cpu, *codec;
+	struct snd_soc_card *card = &data->snd_card;
+	struct device *dev = card->dev;
+	struct of_phandle_args args;
+	int ret, i;
+
+	cpu = of_get_child_by_name(dev->of_node, "cpu");
+	if (!cpu) {
+		dev_err(dev, "platform property missing or invalid\n");
+		return -EINVAL;
+	}
+	codec = of_get_child_by_name(dev->of_node, "codec");
+	if (!codec) {
+		dev_err(dev, "audio-codec property missing or invalid\n");
+		ret = -EINVAL;
+		goto err;
+	}
+
+	ret = of_parse_phandle_with_args(cpu, "sound-dai",
+					 "#sound-dai-cells", 0, &args);
+	if (ret) {
+		dev_err(dev, "codec node missing #sound-dai-cells\n");
+		goto err;
+	}
+	for (i = 0; i < card->num_links; i++)
+		loongson_dai_links[i].cpus->of_node = args.np;
+
+	ret = of_parse_phandle_with_args(codec, "sound-dai",
+					 "#sound-dai-cells", 0, &args);
+	if (ret) {
+		dev_err(dev, "codec node missing #sound-dai-cells\n");
+		goto err;
+	}
+	for (i = 0; i < card->num_links; i++)
+		loongson_dai_links[i].codecs->of_node = args.np;
+
+	snd_soc_of_get_dai_name(cpu, &cpu_dai_name);
+	snd_soc_of_get_dai_name(codec, &codec_dai_name);
+	for (i = 0; i < card->num_links; i++) {
+		loongson_dai_links[i].cpus->dai_name = cpu_dai_name;
+		loongson_dai_links[i].codecs->dai_name = codec_dai_name;
+	}
+	of_node_put(cpu);
+	of_node_put(codec);
+
+	return 0;
+
+err:
+	of_node_put(cpu);
+	of_node_put(codec);
+	return ret;
+}
+
+static int loongson_asoc_card_probe(struct platform_device *pdev)
+{
+	struct loongson_card_data *ls_priv;
+	struct snd_soc_card *card;
+	int ret;
+
+	ls_priv = devm_kzalloc(&pdev->dev, sizeof(*ls_priv), GFP_KERNEL);
+	if (!ls_priv)
+		return -ENOMEM;
+
+	card = &ls_priv->snd_card;
+
+	card->dev = &pdev->dev;
+	card->owner = THIS_MODULE;
+	card->dai_link = loongson_dai_links;
+	card->num_links = ARRAY_SIZE(loongson_dai_links);
+	snd_soc_card_set_drvdata(card, ls_priv);
+
+	ret = device_property_read_string(&pdev->dev, "model", &card->name);
+	if (ret) {
+		dev_err(&pdev->dev, "Error parsing card name: %d\n", ret);
+		return ret;
+	}
+	ret = device_property_read_u32(&pdev->dev, "mclk-fs", &ls_priv->mclk_fs);
+	if (ret) {
+		dev_err(&pdev->dev, "Error parsing mclk-fs: %d\n", ret);
+		return ret;
+	}
+
+	if (has_acpi_companion(&pdev->dev))
+		ret = loongson_card_parse_acpi(ls_priv);
+	else
+		ret = loongson_card_parse_of(ls_priv);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_snd_soc_register_card(&pdev->dev, card);
+
+	return ret;
+}
+
+static const struct of_device_id loongson_asoc_dt_ids[] = {
+	{ .compatible = "loongson,ls-audio-card" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, loongson_asoc_dt_ids);
+
+static struct platform_driver loongson_audio_driver = {
+	.probe = loongson_asoc_card_probe,
+	.driver = {
+		.name = "loongson-asoc-card",
+		.pm = &snd_soc_pm_ops,
+		.of_match_table = of_match_ptr(loongson_asoc_dt_ids),
+	},
+};
+module_platform_driver(loongson_audio_driver);
+
+MODULE_DESCRIPTION("Loongson ASoc Sound Card driver");
+MODULE_AUTHOR("Loongson Technology Corporation Limited");
+MODULE_LICENSE("GPL");