midas_wm1811.c

// SPDX-License-Identifier: GPL-2.0+
//
// Midas audio support
//
// Copyright (C) 2018 Simon Shields <[email protected]>
// Copyright (C) 2020 Samsung Electronics Co., Ltd.

#include <linux/clk.h>
#include <linux/gpio/consumer.h>
#include <linux/iio/consumer.h>
#include <linux/mfd/wm8994/registers.h>
#include <linux/input-event-codes.h>
#include <linux/module.h>
#include <linux/of.h>
#include <sound/jack.h>
#include <sound/soc.h>
#include <sound/soc-dapm.h>

#include "i2s.h"
#include "../codecs/wm8994.h"

/*
 * The MCLK1 clock source is XCLKOUT with its mux set to the external fixed rate
 * oscillator (XXTI).
 */
#define MCLK1_RATE 24000000U
#define MCLK2_RATE 32768U
#define DEFAULT_FLL1_RATE 11289600U

struct midas_priv {
	struct gpio_desc *gpio_fm_sel;
	struct gpio_desc *gpio_lineout_sel;
	struct gpio_desc *gpio_headset_detect;
	struct gpio_desc *gpio_headset_key;
	struct iio_channel *adc_headset_detect;
	unsigned int fll1_rate;

	struct snd_soc_jack headset_jack;
};

static struct snd_soc_jack_pin headset_jack_pins[] = {
	{
		.pin = "Headphone",
		.mask = SND_JACK_HEADPHONE,
	},
	{
		.pin = "Headset Mic",
		.mask = SND_JACK_MICROPHONE,
	},
};

/*
 * min_mv/max_mv values in this struct are set up based on DT values.
 */
static struct snd_soc_jack_zone headset_jack_zones[] = {
	{ .jack_type = SND_JACK_HEADPHONE, },
	{ .jack_type = SND_JACK_HEADSET, },
	{ .jack_type = SND_JACK_HEADPHONE, },
};

/*
 * This is used for manual detection in headset_key_check, we reuse the
 * structure since it's convenient.
 *
 * min_mv/max_mv values in this struct are set up based on DT values.
 */
static struct snd_soc_jack_zone headset_key_zones[] = {
	{ .jack_type = SND_JACK_BTN_0, },  /* Media */
	{ .jack_type = SND_JACK_BTN_1, },  /* Volume Up */
	{ .jack_type = SND_JACK_BTN_2, },  /* Volume Down */
};

static int headset_jack_check(void *data)
{
	struct snd_soc_component *codec = data;
	struct snd_soc_dapm_context *dapm = snd_soc_component_get_dapm(codec);
	struct midas_priv *priv = snd_soc_card_get_drvdata(codec->card);
	int adc, ret;
	int jack_type = 0;

	if (!gpiod_get_value_cansleep(priv->gpio_headset_detect))
		return 0;

	/* Enable headset mic bias regulator so that the ADC reading works */
	ret = snd_soc_dapm_force_enable_pin(dapm, "headset-mic-bias");
	if (ret < 0) {
		pr_err("%s: Failed to enable headset mic bias regulator (%d), assuming headphones\n",
		       __func__, ret);
		return SND_JACK_HEADPHONE;
	}
	snd_soc_dapm_sync(dapm);

	/* Sleep for a small amount of time to get the value to stabilize */
	msleep(20);

	ret = iio_read_channel_processed(priv->adc_headset_detect, &adc);
	if (ret) {
		pr_err("%s: Failed to read ADC (%d), assuming headphones\n",
		       __func__, ret);
		jack_type = SND_JACK_HEADPHONE;
		goto out;
	}
	pr_debug("%s: ADC value is %d\n", __func__, adc);

	jack_type = snd_soc_jack_get_type(&priv->headset_jack, adc);

out:
	ret = snd_soc_dapm_disable_pin(dapm, "headset-mic-bias");
	if (ret < 0)
		pr_err("%s: Failed to disable headset mic bias regulator (%d)\n",
		       __func__, ret);
	snd_soc_dapm_sync(dapm);

	return jack_type;
}

static int headset_key_check(void *data)
{
	struct snd_soc_component *codec = data;
	struct midas_priv *priv = snd_soc_card_get_drvdata(codec->card);
	int adc, i, ret;

	if (!gpiod_get_value_cansleep(priv->gpio_headset_key))
		return 0;

	/* Filter out keypresses when 4 pole jack not detected */
	if (!(priv->headset_jack.status & SND_JACK_MICROPHONE))
		return 0;

	ret = iio_read_channel_processed(priv->adc_headset_detect, &adc);
	if (ret) {
		pr_err("%s: Failed to read ADC (%d), can't detect key type\n",
		       __func__, ret);
		return 0;
	}
	pr_debug("%s: ADC value is %d\n", __func__, adc);

	for (i = 0; i < ARRAY_SIZE(headset_key_zones); i++) {
		if (adc >= headset_key_zones[i].min_mv &&
		    adc <= headset_key_zones[i].max_mv) {
			return headset_key_zones[i].jack_type;
		}
	}

	return 0;
}

static struct snd_soc_jack_gpio headset_gpio[] = {
	{
		.name = "Headset Jack",
		.report = SND_JACK_HEADSET,
		.debounce_time = 150,
		.jack_status_check = headset_jack_check,
	},
	{
		.name = "Headset Key",
		.report = SND_JACK_BTN_0 | SND_JACK_BTN_1 | SND_JACK_BTN_2,
		.debounce_time = 30,
		.jack_status_check = headset_key_check,
	},
};

static int midas_start_fll1(struct snd_soc_pcm_runtime *rtd, unsigned int rate)
{
	struct snd_soc_card *card = rtd->card;
	struct midas_priv *priv = snd_soc_card_get_drvdata(card);
	struct snd_soc_dai *aif1_dai = snd_soc_rtd_to_codec(rtd, 0);
	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
	int ret;

	if (!rate)
		rate = priv->fll1_rate;
	/*
	 * If no new rate is requested, set FLL1 to a sane default for jack
	 * detection.
	 */
	if (!rate)
		rate = DEFAULT_FLL1_RATE;

	if (rate != priv->fll1_rate && priv->fll1_rate) {
		/* while reconfiguring, switch to MCLK2 for SYSCLK */
		ret = snd_soc_dai_set_sysclk(aif1_dai, WM8994_SYSCLK_MCLK2,
					     MCLK2_RATE, SND_SOC_CLOCK_IN);
		if (ret < 0) {
			dev_err(card->dev, "Unable to switch to MCLK2: %d\n", ret);
			return ret;
		}
	}

	ret = snd_soc_dai_set_pll(aif1_dai, WM8994_FLL1, WM8994_FLL_SRC_MCLK1,
				  MCLK1_RATE, rate);
	if (ret < 0) {
		dev_err(card->dev, "Failed to set FLL1 rate: %d\n", ret);
		return ret;
	}
	priv->fll1_rate = rate;

	ret = snd_soc_dai_set_sysclk(aif1_dai, WM8994_SYSCLK_FLL1,
				     priv->fll1_rate, SND_SOC_CLOCK_IN);
	if (ret < 0) {
		dev_err(card->dev, "Failed to set SYSCLK source: %d\n", ret);
		return ret;
	}

	ret = snd_soc_dai_set_sysclk(cpu_dai, SAMSUNG_I2S_OPCLK, 0,
				     SAMSUNG_I2S_OPCLK_PCLK);
	if (ret < 0) {
		dev_err(card->dev, "Failed to set OPCLK source: %d\n", ret);
		return ret;
	}

	return 0;
}

static int midas_stop_fll1(struct snd_soc_pcm_runtime *rtd)
{
	struct snd_soc_card *card = rtd->card;
	struct midas_priv *priv = snd_soc_card_get_drvdata(card);
	struct snd_soc_dai *aif1_dai = snd_soc_rtd_to_codec(rtd, 0);
	int ret;

	ret = snd_soc_dai_set_sysclk(aif1_dai, WM8994_SYSCLK_MCLK2,
				     MCLK2_RATE, SND_SOC_CLOCK_IN);
	if (ret < 0) {
		dev_err(card->dev, "Unable to switch to MCLK2: %d\n", ret);
		return ret;
	}

	ret = snd_soc_dai_set_pll(aif1_dai, WM8994_FLL1, 0, 0, 0);
	if (ret < 0) {
		dev_err(card->dev, "Unable to stop FLL1: %d\n", ret);
		return ret;
	}

	priv->fll1_rate = 0;

	return 0;
}

static int midas_aif1_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
	unsigned int pll_out;

	/* AIF1CLK should be at least 3MHz for "optimal performance" */
	if (params_rate(params) == 8000 || params_rate(params) == 11025)
		pll_out = params_rate(params) * 512;
	else
		pll_out = params_rate(params) * 256;

	return midas_start_fll1(rtd, pll_out);
}

static const struct snd_soc_ops midas_aif1_ops = {
	.hw_params = midas_aif1_hw_params,
};

/*
 * We only have a single external speaker, so mix stereo data
 * to a single mono stream.
 */
static int midas_ext_spkmode(struct snd_soc_dapm_widget *w,
			     struct snd_kcontrol *kcontrol, int event)
{
	struct snd_soc_component *codec = snd_soc_dapm_to_component(w->dapm);
	int ret = 0;

	switch (event) {
	case SND_SOC_DAPM_PRE_PMU:
		ret = snd_soc_component_update_bits(codec, WM8994_SPKOUT_MIXERS,
				  WM8994_SPKMIXR_TO_SPKOUTL_MASK,
				  WM8994_SPKMIXR_TO_SPKOUTL);
		break;
	case SND_SOC_DAPM_POST_PMD:
		ret = snd_soc_component_update_bits(codec, WM8994_SPKOUT_MIXERS,
				  WM8994_SPKMIXR_TO_SPKOUTL_MASK,
				  0);
		break;
	}

	return ret;
}

static int midas_fm_set(struct snd_soc_dapm_widget *w,
			struct snd_kcontrol *kcontrol, int event)
{
	struct snd_soc_card *card = w->dapm->card;
	struct midas_priv *priv = snd_soc_card_get_drvdata(card);

	if (!priv->gpio_fm_sel)
		return 0;

	switch (event) {
	case SND_SOC_DAPM_PRE_PMU:
		gpiod_set_value_cansleep(priv->gpio_fm_sel, 1);
		break;
	case SND_SOC_DAPM_POST_PMD:
		gpiod_set_value_cansleep(priv->gpio_fm_sel, 0);
		break;
	}

	return 0;
}

static int midas_line_set(struct snd_soc_dapm_widget *w,
			  struct snd_kcontrol *kcontrol, int event)
{
	struct snd_soc_card *card = w->dapm->card;
	struct midas_priv *priv = snd_soc_card_get_drvdata(card);

	if (!priv->gpio_lineout_sel)
		return 0;

	switch (event) {
	case SND_SOC_DAPM_PRE_PMU:
		gpiod_set_value_cansleep(priv->gpio_lineout_sel, 1);
		break;
	case SND_SOC_DAPM_POST_PMD:
		gpiod_set_value_cansleep(priv->gpio_lineout_sel, 0);
		break;
	}

	return 0;
}

static const struct snd_kcontrol_new midas_controls[] = {
	SOC_DAPM_PIN_SWITCH("HP"),

	SOC_DAPM_PIN_SWITCH("SPK"),
	SOC_DAPM_PIN_SWITCH("RCV"),

	SOC_DAPM_PIN_SWITCH("LINE"),
	SOC_DAPM_PIN_SWITCH("HDMI"),

	SOC_DAPM_PIN_SWITCH("Main Mic"),
	SOC_DAPM_PIN_SWITCH("Sub Mic"),
	SOC_DAPM_PIN_SWITCH("Headset Mic"),

	SOC_DAPM_PIN_SWITCH("FM In"),
};

static const struct snd_soc_dapm_widget midas_dapm_widgets[] = {
	SND_SOC_DAPM_HP("HP", NULL),

	SND_SOC_DAPM_SPK("SPK", midas_ext_spkmode),
	SND_SOC_DAPM_SPK("RCV", NULL),

	/* FIXME: toggle MAX77693 on i9300/i9305 */
	SND_SOC_DAPM_LINE("LINE", midas_line_set),
	SND_SOC_DAPM_LINE("HDMI", NULL),
	SND_SOC_DAPM_LINE("FM In", midas_fm_set),

	SND_SOC_DAPM_HP("Headphone", NULL),
	SND_SOC_DAPM_MIC("Headset Mic", NULL),
	SND_SOC_DAPM_REGULATOR_SUPPLY("headset-mic-bias", 0, 0),
	SND_SOC_DAPM_MIC("Main Mic", NULL),
	SND_SOC_DAPM_REGULATOR_SUPPLY("mic-bias", 0, 0),
	SND_SOC_DAPM_MIC("Sub Mic", NULL),
	SND_SOC_DAPM_REGULATOR_SUPPLY("submic-bias", 0, 0),
};

/* Default routing; supplemented by audio-routing DT property */
static const struct snd_soc_dapm_route midas_dapm_routes[] = {
	/* Bind microphones with their respective regulator supplies */
	{"Main Mic", NULL, "mic-bias"},
	{"Sub Mic", NULL, "submic-bias"},
	{"Headset Mic", NULL, "headset-mic-bias"},
};

static int midas_set_bias_level(struct snd_soc_card *card,
				struct snd_soc_dapm_context *dapm,
				enum snd_soc_bias_level level)
{
	struct snd_soc_pcm_runtime *rtd = snd_soc_get_pcm_runtime(card,
						  &card->dai_link[0]);
	struct snd_soc_dai *aif1_dai = snd_soc_rtd_to_codec(rtd, 0);

	if (dapm->dev != aif1_dai->dev)
		return 0;

	switch (level) {
	case SND_SOC_BIAS_STANDBY:
		return midas_stop_fll1(rtd);
	case SND_SOC_BIAS_PREPARE:
		return midas_start_fll1(rtd, 0);
	default:
		break;
	}

	return 0;
}

static int midas_late_probe(struct snd_soc_card *card)
{
	struct snd_soc_pcm_runtime *rtd = snd_soc_get_pcm_runtime(card,
							&card->dai_link[0]);
	struct snd_soc_dai *aif1_dai = snd_soc_rtd_to_codec(rtd, 0);
	struct midas_priv *priv = snd_soc_card_get_drvdata(card);
	int ret;

	/* Use MCLK2 as SYSCLK for boot */
	ret = snd_soc_dai_set_sysclk(aif1_dai, WM8994_SYSCLK_MCLK2, MCLK2_RATE,
				     SND_SOC_CLOCK_IN);
	if (ret < 0) {
		dev_err(aif1_dai->dev, "Failed to switch to MCLK2: %d\n", ret);
		return ret;
	}

	if (!priv->gpio_headset_detect) {
		ret = snd_soc_card_jack_new_pins(card, "Headset",
				 SND_JACK_HEADSET | SND_JACK_MECHANICAL |
				 SND_JACK_BTN_0 | SND_JACK_BTN_1 |
				 SND_JACK_BTN_2 | SND_JACK_BTN_3 |
				 SND_JACK_BTN_4 | SND_JACK_BTN_5,
				 &priv->headset_jack,
				 headset_jack_pins,
				 ARRAY_SIZE(headset_jack_pins));
		if (ret)
			return ret;

		wm8958_mic_detect(aif1_dai->component, &priv->headset_jack,
				  NULL, NULL, NULL, NULL);
	} else {
		/* Some devices (n8000, t310) use a GPIO to detect the jack. */
		ret = snd_soc_card_jack_new_pins(card, "Headset",
				SND_JACK_HEADSET | SND_JACK_BTN_0 |
				SND_JACK_BTN_1 | SND_JACK_BTN_2,
				&priv->headset_jack,
				headset_jack_pins,
				ARRAY_SIZE(headset_jack_pins));
		if (ret) {
			dev_err(card->dev,
				"Failed to set up headset pins: %d\n", ret);
			return ret;
		}

		ret = snd_soc_jack_add_zones(&priv->headset_jack,
				ARRAY_SIZE(headset_jack_zones),
				headset_jack_zones);
		if (ret) {
			dev_err(card->dev,
				"Failed to set up headset zones: %d\n", ret);
			return ret;
		}

		headset_gpio[0].data = aif1_dai->component;
		headset_gpio[0].desc = priv->gpio_headset_detect;

		headset_gpio[1].data = aif1_dai->component;
		headset_gpio[1].desc = priv->gpio_headset_key;

		snd_jack_set_key(priv->headset_jack.jack,
				 SND_JACK_BTN_0, KEY_MEDIA);
		snd_jack_set_key(priv->headset_jack.jack,
				 SND_JACK_BTN_1, KEY_VOLUMEUP);
		snd_jack_set_key(priv->headset_jack.jack,
				 SND_JACK_BTN_2, KEY_VOLUMEDOWN);

		ret = snd_soc_jack_add_gpios(&priv->headset_jack,
				ARRAY_SIZE(headset_gpio),
				headset_gpio);
		if (ret)
			dev_err(card->dev,
				"Failed to set up headset jack GPIOs: %d\n",
				ret);

		return ret;
	}

	return 0;
}

static struct snd_soc_dai_driver midas_ext_dai[] = {
	{
		.name = "Voice call",
		.playback = {
			.channels_min = 1,
			.channels_max = 2,
			.rate_min = 8000,
			.rate_max = 16000,
			.rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000),
			.formats = SNDRV_PCM_FMTBIT_S16_LE,
		},
		.capture = {
			.channels_min = 1,
			.channels_max = 2,
			.rate_min = 8000,
			.rate_max = 16000,
			.rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000),
			.formats = SNDRV_PCM_FMTBIT_S16_LE,
		},
	},
	{
		.name = "Bluetooth",
		.playback = {
			.channels_min = 1,
			.channels_max = 2,
			.rate_min = 8000,
			.rate_max = 16000,
			.rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000),
			.formats = SNDRV_PCM_FMTBIT_S16_LE,
		},
		.capture = {
			.channels_min = 1,
			.channels_max = 2,
			.rate_min = 8000,
			.rate_max = 16000,
			.rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000),
			.formats = SNDRV_PCM_FMTBIT_S16_LE,
		},
	},
};

static const struct snd_soc_component_driver midas_component = {
	.name	= "midas-audio",
};

SND_SOC_DAILINK_DEFS(wm1811_hifi,
	DAILINK_COMP_ARRAY(COMP_EMPTY()),
	DAILINK_COMP_ARRAY(COMP_CODEC(NULL, "wm8994-aif1")),
	DAILINK_COMP_ARRAY(COMP_EMPTY()));

SND_SOC_DAILINK_DEFS(wm1811_voice,
	DAILINK_COMP_ARRAY(COMP_EMPTY()),
	DAILINK_COMP_ARRAY(COMP_CODEC(NULL, "wm8994-aif2")),
	DAILINK_COMP_ARRAY(COMP_EMPTY()));

SND_SOC_DAILINK_DEFS(wm1811_bt,
	DAILINK_COMP_ARRAY(COMP_EMPTY()),
	DAILINK_COMP_ARRAY(COMP_CODEC(NULL, "wm8994-aif3")),
	DAILINK_COMP_ARRAY(COMP_EMPTY()));

static struct snd_soc_dai_link midas_dai[] = {
	{
		.name = "WM8994 AIF1",
		.stream_name = "HiFi Primary",
		.ops = &midas_aif1_ops,
		.dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
			SND_SOC_DAIFMT_CBP_CFP,
		SND_SOC_DAILINK_REG(wm1811_hifi),
	}, {
		.name = "WM1811 Voice",
		.stream_name = "Voice call",
		.ignore_suspend = 1,
		SND_SOC_DAILINK_REG(wm1811_voice),
	}, {
		.name = "WM1811 BT",
		.stream_name = "Bluetooth",
		.ignore_suspend = 1,
		SND_SOC_DAILINK_REG(wm1811_bt),
	},
};

static struct snd_soc_card midas_card = {
	.name = "Midas WM1811",
	.owner = THIS_MODULE,

	.dai_link = midas_dai,
	.num_links = ARRAY_SIZE(midas_dai),
	.controls = midas_controls,
	.num_controls = ARRAY_SIZE(midas_controls),
	.dapm_widgets = midas_dapm_widgets,
	.num_dapm_widgets = ARRAY_SIZE(midas_dapm_widgets),
	.dapm_routes = midas_dapm_routes,
	.num_dapm_routes = ARRAY_SIZE(midas_dapm_routes),

	.set_bias_level = midas_set_bias_level,
	.late_probe = midas_late_probe,
};

static int midas_probe(struct platform_device *pdev)
{
	struct device_node *cpu_dai_node = NULL, *codec_dai_node = NULL;
	struct device_node *cpu = NULL, *codec = NULL;
	struct snd_soc_card *card = &midas_card;
	struct device *dev = &pdev->dev;
	static struct snd_soc_dai_link *dai_link;
	enum iio_chan_type channel_type;
	u32 fourpole_threshold[2];
	u32 button_threshold[3];
	struct midas_priv *priv;
	int ret, i;

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	snd_soc_card_set_drvdata(card, priv);
	card->dev = dev;

	priv->gpio_fm_sel = devm_gpiod_get_optional(dev, "fm-sel", GPIOD_OUT_HIGH);
	if (IS_ERR(priv->gpio_fm_sel))
		return dev_err_probe(dev, PTR_ERR(priv->gpio_fm_sel),
				     "Failed to get FM selection GPIO\n");

	priv->gpio_lineout_sel = devm_gpiod_get_optional(dev, "lineout-sel",
						    GPIOD_OUT_HIGH);
	if (IS_ERR(priv->gpio_lineout_sel))
		return dev_err_probe(dev, PTR_ERR(priv->gpio_lineout_sel),
				     "Failed to get line out selection GPIO\n");

	priv->gpio_headset_detect = devm_gpiod_get_optional(dev,
				"headset-detect", GPIOD_IN);
	if (IS_ERR(priv->gpio_headset_detect))
		return dev_err_probe(dev, PTR_ERR(priv->gpio_headset_detect),
				     "Failed to get headset jack detect GPIO\n");

	if (priv->gpio_headset_detect) {
		priv->adc_headset_detect = devm_iio_channel_get(dev,
							"headset-detect");
		if (IS_ERR(priv->adc_headset_detect))
			return dev_err_probe(dev,
					     PTR_ERR(priv->adc_headset_detect),
					     "Failed to get ADC channel\n");

		ret = iio_get_channel_type(priv->adc_headset_detect,
					   &channel_type);
		if (ret) {
			dev_err(dev, "Failed to get ADC channel type\n");
			return ret;
		}

		if (channel_type != IIO_VOLTAGE) {
			dev_err(dev, "ADC channel is not voltage\n");
			return -EINVAL;
		}

		priv->gpio_headset_key = devm_gpiod_get(dev, "headset-key",
							GPIOD_IN);
		if (IS_ERR(priv->gpio_headset_key))
			return dev_err_probe(dev,
					     PTR_ERR(priv->gpio_headset_key),
					     "Failed to get headset key GPIO\n");

		ret = of_property_read_u32_array(dev->of_node,
				"samsung,headset-4pole-threshold-microvolt",
				fourpole_threshold,
				ARRAY_SIZE(fourpole_threshold));
		if (ret) {
			dev_err(dev, "Failed to get 4-pole jack detection threshold\n");
			return ret;
		}

		if (fourpole_threshold[0] > fourpole_threshold[1]) {
			dev_err(dev, "Invalid 4-pole jack detection threshold value\n");
			return -EINVAL;
		}

		headset_jack_zones[0].max_mv = (fourpole_threshold[0]);
		headset_jack_zones[1].min_mv = (fourpole_threshold[0] + 1);

		headset_jack_zones[1].max_mv = (fourpole_threshold[1]);
		headset_jack_zones[2].min_mv = (fourpole_threshold[1] + 1);

		ret = of_property_read_u32_array(dev->of_node,
				"samsung,headset-button-threshold-microvolt",
				button_threshold,
				ARRAY_SIZE(button_threshold));
		if (ret) {
			dev_err(dev, "Failed to get headset button detection threshold\n");
			return ret;
		}

		if (button_threshold[0] > button_threshold[1] ||
		    button_threshold[1] > button_threshold[2]) {
			dev_err(dev, "Invalid headset button detection threshold value\n");
			return -EINVAL;
		}

		for (i = 0; i < 3; i++) {
			if (i != 0 && button_threshold[i] <= 0) {
				dev_err(dev, "Invalid headset button detection threshold value\n");
				return -EINVAL;
			}

			headset_key_zones[i].min_mv = button_threshold[i];

			if (i == 2)
				headset_key_zones[i].max_mv = UINT_MAX;
			else
				headset_key_zones[i].max_mv = \
						(button_threshold[i+1] - 1);
		}
	}

	ret = snd_soc_of_parse_card_name(card, "model");
	if (ret < 0) {
		dev_err(dev, "Card name is not specified\n");
		return ret;
	}

	ret = snd_soc_of_parse_audio_routing(card, "audio-routing");
	if (ret < 0) {
		/* Backwards compatible way */
		ret = snd_soc_of_parse_audio_routing(card, "samsung,audio-routing");
		if (ret < 0) {
			dev_err(dev, "Audio routing invalid/unspecified\n");
			return ret;
		}
	}

	cpu = of_get_child_by_name(dev->of_node, "cpu");
	if (!cpu)
		return -EINVAL;

	codec = of_get_child_by_name(dev->of_node, "codec");
	if (!codec) {
		of_node_put(cpu);
		return -EINVAL;
	}

	cpu_dai_node = of_parse_phandle(cpu, "sound-dai", 0);
	of_node_put(cpu);
	if (!cpu_dai_node) {
		dev_err(dev, "parsing cpu/sound-dai failed\n");
		of_node_put(codec);
		return -EINVAL;
	}

	codec_dai_node = of_parse_phandle(codec, "sound-dai", 0);
	of_node_put(codec);
	if (!codec_dai_node) {
		dev_err(dev, "audio-codec property invalid/missing\n");
		ret = -EINVAL;
		goto put_cpu_dai_node;
	}

	for_each_card_prelinks(card, i, dai_link) {
		dai_link->codecs->of_node = codec_dai_node;
		dai_link->cpus->of_node = cpu_dai_node;
		dai_link->platforms->of_node = cpu_dai_node;
	}

	ret = devm_snd_soc_register_component(dev, &midas_component,
			midas_ext_dai, ARRAY_SIZE(midas_ext_dai));
	if (ret < 0) {
		dev_err(dev, "Failed to register component: %d\n", ret);
		goto put_codec_dai_node;
	}

	ret = devm_snd_soc_register_card(dev, card);
	if (ret < 0) {
		dev_err(dev, "Failed to register card: %d\n", ret);
		goto put_codec_dai_node;
	}

	return 0;

put_codec_dai_node:
	of_node_put(codec_dai_node);
put_cpu_dai_node:
	of_node_put(cpu_dai_node);
	return ret;
}

static const struct of_device_id midas_of_match[] = {
	{ .compatible = "samsung,midas-audio" },
	{ },
};
MODULE_DEVICE_TABLE(of, midas_of_match);

static struct platform_driver midas_driver = {
	.driver = {
		.name = "midas-audio",
		.of_match_table = midas_of_match,
		.pm = &snd_soc_pm_ops,
	},
	.probe = midas_probe,
};
module_platform_driver(midas_driver);

MODULE_AUTHOR("Simon Shields <[email protected]>");
MODULE_DESCRIPTION("ASoC support for Midas");
MODULE_LICENSE("GPL v2");