TDA4VM: How add new snd card in linux?

/*
 * dummy_codec.c  --  dummy audio codec
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/clk.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <sound/soc.h>
#include <sound/pcm.h>
#include <sound/initval.h>

struct a2b_net_cfg {
	int id;
};

struct dummy_codec_priv {
	struct snd_soc_codec *codec;
	struct a2b_net_cfg a2b_cfg;
};

static int dummy_codec_startup(struct snd_pcm_substream *substream,
			       struct snd_soc_dai *dai)
{
	return 0;
}

static void dummy_codec_shutdown(struct snd_pcm_substream *substream,
				 struct snd_soc_dai *dai)
{
    return;
}

static struct snd_soc_dai_ops dummy_codec_dai_ops = {
	.startup	= dummy_codec_startup,
	.shutdown	= dummy_codec_shutdown,
};

static struct snd_soc_dai_driver a2b_dai[] = {
	{
		.name = "a2b-codec-0",
		.playback = {
			.stream_name = "a2b Playback",
			.channels_min = 2,
			.channels_max = 32,
			.rates = SNDRV_PCM_RATE_8000_192000,
			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
					SNDRV_PCM_FMTBIT_S20_3LE |
					SNDRV_PCM_FMTBIT_S24_LE |
					SNDRV_PCM_FMTBIT_S32_LE),
		},
		.capture = {
			.stream_name = "a2b Capture",
			.channels_min = 2,
			.channels_max = 32,
			.rates = SNDRV_PCM_RATE_8000_192000,
			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
					SNDRV_PCM_FMTBIT_S20_3LE |
					SNDRV_PCM_FMTBIT_S24_LE |
					SNDRV_PCM_FMTBIT_S32_LE),
		},
		.ops = &dummy_codec_dai_ops,
	},
	{
		.name = "a2b-codec-1",
		.playback = {
			.stream_name = "a2b Playback",
			.channels_min = 2,
			.channels_max = 32,
			.rates = SNDRV_PCM_RATE_8000_192000,
			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
					SNDRV_PCM_FMTBIT_S20_3LE |
					SNDRV_PCM_FMTBIT_S24_LE |
					SNDRV_PCM_FMTBIT_S32_LE),
		},
		.capture = {
			.stream_name = "a2b Capture",
			.channels_min = 2,
			.channels_max = 32,
			.rates = SNDRV_PCM_RATE_8000_192000,
			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
					SNDRV_PCM_FMTBIT_S20_3LE |
					SNDRV_PCM_FMTBIT_S24_LE |
					SNDRV_PCM_FMTBIT_S32_LE),
		},
		.ops = &dummy_codec_dai_ops,
	},
	{
		.name = "a2b-codec-2",
		.playback = {
			.stream_name = "a2b Playback",
			.channels_min = 2,
			.channels_max = 32,
			.rates = SNDRV_PCM_RATE_8000_192000,
			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
					SNDRV_PCM_FMTBIT_S20_3LE |
					SNDRV_PCM_FMTBIT_S24_LE |
					SNDRV_PCM_FMTBIT_S32_LE),
		},
		.capture = {
			.stream_name = "a2b Capture",
			.channels_min = 2,
			.channels_max = 32,
			.rates = SNDRV_PCM_RATE_8000_192000,
			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
					SNDRV_PCM_FMTBIT_S20_3LE |
					SNDRV_PCM_FMTBIT_S24_LE |
					SNDRV_PCM_FMTBIT_S32_LE),
		},
		.ops = &dummy_codec_dai_ops,
	},
    {
    	.name = "fpga-codec-0",
		.playback = {
			.stream_name = "fpga Playback",
			.channels_min = 2,
			.channels_max = 32,
			.rates = SNDRV_PCM_RATE_8000_192000,
			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
					SNDRV_PCM_FMTBIT_S20_3LE |
					SNDRV_PCM_FMTBIT_S24_LE |
					SNDRV_PCM_FMTBIT_S32_LE),
		},
		.capture = {
			.stream_name = "fpga Capture",
			.channels_min = 2,
			.channels_max = 32,
			.rates = SNDRV_PCM_RATE_8000_192000,
			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
					SNDRV_PCM_FMTBIT_S20_3LE |
					SNDRV_PCM_FMTBIT_S24_LE |
					SNDRV_PCM_FMTBIT_S32_LE),
		},
		.ops = &dummy_codec_dai_ops,
    },
    {
    	.name = "fpga-codec-1",
		.playback = {
			.stream_name = "fpga Playback",
			.channels_min = 2,
			.channels_max = 32,
			.rates = SNDRV_PCM_RATE_8000_192000,
			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
					SNDRV_PCM_FMTBIT_S20_3LE |
					SNDRV_PCM_FMTBIT_S24_LE |
					SNDRV_PCM_FMTBIT_S32_LE),
		},
		.capture = {
			.stream_name = "fpga Capture",
			.channels_min = 2,
			.channels_max = 32,
			.rates = SNDRV_PCM_RATE_8000_192000,
			.formats = (SNDRV_PCM_FMTBIT_S16_LE |
					SNDRV_PCM_FMTBIT_S20_3LE |
					SNDRV_PCM_FMTBIT_S24_LE |
					SNDRV_PCM_FMTBIT_S32_LE),
		},
		.ops = &dummy_codec_dai_ops,
    }
};

static struct snd_soc_component_driver soc_a2b_codec = {
	.name = "a2b-codec",
};

static int autox_dummy_codec_probe(struct platform_device *pdev)
{
	struct dummy_codec_priv *codec_priv = NULL;
	struct device_node *np = pdev->dev.of_node;
	int ret, val;

	codec_priv = devm_kzalloc(&pdev->dev, sizeof(*codec_priv),
				  GFP_KERNEL);
	if (!codec_priv)
		return -ENOMEM;
	platform_set_drvdata(pdev, codec_priv);

	if (np != NULL) {
		ret = of_property_read_u32(np, "id", &val);
		if (ret >= 0 && val>=0 && val < ARRAY_SIZE(a2b_dai))
			codec_priv->a2b_cfg.id = val;
		else {
			dev_warn(&pdev->dev, "Unable to get id\n");
		}
	}

	return devm_snd_soc_register_component(&pdev->dev, &soc_a2b_codec,
				      &a2b_dai[codec_priv->a2b_cfg.id], 1);
}

static int autox_dummy_codec_remove(struct platform_device *pdev)
{
	return 0;
}

static const struct of_device_id autox_dummy_codec_of_match[] = {
	{ .compatible = "autox,a2b-codec", },
	{},
};
MODULE_DEVICE_TABLE(of, autox_dummy_codec_of_match);

static struct platform_driver autox_dummy_codec_driver = {
	.driver = {
		.name = "A2B-codec",
		.of_match_table = of_match_ptr(autox_dummy_codec_of_match),
	},
	.probe = autox_dummy_codec_probe,
	.remove = autox_dummy_codec_remove,
};

module_platform_driver(autox_dummy_codec_driver);

MODULE_AUTHOR("Eason <zhanxingzhou@autox.ai>");
MODULE_DESCRIPTION("autox Dummy Codec Driver");
MODULE_LICENSE("GPL v2");