---

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/of_device.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <linux/version.h>

#define NS4168_RATES SNDRV_PCM_RATE_8000_48000

#define NS4168_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE)

struct ns4168_priv {
	int sysclk;
};

/* DAPM виджеты для моно-усилителя */
static const struct snd_soc_dapm_widget ns4168_dapm_widgets[] = {
	SND_SOC_DAPM_DAC("DAC", "Playback", SND_SOC_NOPM, 0, 0),
	SND_SOC_DAPM_OUTPUT("MONOOUT"),
};

static const struct snd_soc_dapm_route ns4168_dapm_routes[] = {
	{ "MONOOUT", NULL, "DAC" },
};

static int ns4168_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *dai)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	static struct snd_pcm_hw_constraint_list constraint_rates;
	static u32 support_rates[] = {8000, 16000, 32000, 44100, 48000};
	int ret;

	constraint_rates.list = support_rates;
	constraint_rates.count = ARRAY_SIZE(support_rates);
	ret = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, &constraint_rates);
	if (ret)
		return ret;

	return 0;
}

static int ns4168_set_fmt(struct snd_soc_dai *codec_dai, unsigned int fmt)
{
	fmt &= (SND_SOC_DAIFMT_FORMAT_MASK | SND_SOC_DAIFMT_INV_MASK |
		SND_SOC_DAIFMT_MASTER_MASK);

	/* Разрешаем работу в I2S и в честном однослотовом DSP_A (PCM) режиме */
	if (fmt != (SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF | SND_SOC_DAIFMT_CBS_CFS) &&
	    fmt != (SND_SOC_DAIFMT_DSP_A | SND_SOC_DAIFMT_NB_NF | SND_SOC_DAIFMT_CBS_CFS)) {
		dev_err(codec_dai->dev, "Invalid DAI format\n");
		return -EINVAL;
	}

	return 0;
}

static const struct snd_soc_dai_ops ns4168_dai_ops = {
	.startup	= ns4168_startup,
	.set_fmt	= ns4168_set_fmt,
};

static struct snd_soc_dai_driver ns4168_dai = {
	.name = "ns4168-hifi",
	.playback = {
		.stream_name = "Playback",
		.channels_min = 1,          /* Разрешаем честный 1 канал (Моно) */
		.channels_max = 2,          /* Максимум 2 для совместимости */
		.rates = NS4168_RATES,
		.formats = NS4168_FORMATS,
	},
	.ops = &ns4168_dai_ops,
};

static const struct snd_soc_component_driver soc_component_dev_ns4168 = {
	.dapm_widgets		= ns4168_dapm_widgets,
	.num_dapm_widgets	= ARRAY_SIZE(ns4168_dapm_widgets),
	.dapm_routes		= ns4168_dapm_routes,
	.num_dapm_routes	= ARRAY_SIZE(ns4168_dapm_routes),
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 19, 154)
	.idle_bias_on		= 1,
	.use_pmdown_time	= 1,
	.endianness		= 1,
	.legacy_dai_naming	= 1,
#endif
};

static const struct of_device_id ns4168_of_match[] = {
	{ .compatible = "fsl,ns4168" },
	{ /* sentinel*/ }
};
MODULE_DEVICE_TABLE(of, ns4168_of_match);

static int ns4168_codec_probe(struct platform_device *pdev)
{
	struct ns4168_priv *ns4168;

	ns4168 = devm_kzalloc(&pdev->dev, sizeof(struct ns4168_priv), GFP_KERNEL);
	if (ns4168 == NULL)
		return -ENOMEM;
	platform_set_drvdata(pdev, ns4168);

	return devm_snd_soc_register_component(&pdev->dev,
			&soc_component_dev_ns4168, &ns4168_dai, 1);
}

static struct platform_driver ns4168_codec_driver = {
	.probe		= ns4168_codec_probe,
	.driver		= {
		.name	= "ns4168-codec",
		.of_match_table = ns4168_of_match,
	},
};
module_platform_driver(ns4168_codec_driver);

MODULE_DESCRIPTION("ASoC NS4168 Mono Amplifier Driver");
MODULE_AUTHOR("Vovan");
MODULE_LICENSE("GPL");