sound/soc/codecs/max98373-i2c.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 // Copyright (c) 2017, Maxim Integrated

 #include <linux/acpi.h>
 #include <linux/delay.h>
 #include <linux/gpio.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/pm.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/cdev.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
 #include <sound/tlv.h>
 #include "max98373.h"

 static const u32 max98373_i2c_cache_reg[] = {
 	MAX98373_R2054_MEAS_ADC_PVDD_CH_READBACK,
 	MAX98373_R2055_MEAS_ADC_THERM_CH_READBACK,
 	MAX98373_R20B6_BDE_CUR_STATE_READBACK,
 };

 static struct reg_default max98373_reg[] = {
 	{MAX98373_R2000_SW_RESET, 0x00},
 	{MAX98373_R2001_INT_RAW1, 0x00},
 	{MAX98373_R2002_INT_RAW2, 0x00},
 	{MAX98373_R2003_INT_RAW3, 0x00},
 	{MAX98373_R2004_INT_STATE1, 0x00},
 	{MAX98373_R2005_INT_STATE2, 0x00},
 	{MAX98373_R2006_INT_STATE3, 0x00},
 	{MAX98373_R2007_INT_FLAG1, 0x00},
 	{MAX98373_R2008_INT_FLAG2, 0x00},
 	{MAX98373_R2009_INT_FLAG3, 0x00},
 	{MAX98373_R200A_INT_EN1, 0x00},
 	{MAX98373_R200B_INT_EN2, 0x00},
 	{MAX98373_R200C_INT_EN3, 0x00},
 	{MAX98373_R200D_INT_FLAG_CLR1, 0x00},
 	{MAX98373_R200E_INT_FLAG_CLR2, 0x00},
 	{MAX98373_R200F_INT_FLAG_CLR3, 0x00},
 	{MAX98373_R2010_IRQ_CTRL, 0x00},
 	{MAX98373_R2014_THERM_WARN_THRESH, 0x10},
 	{MAX98373_R2015_THERM_SHDN_THRESH, 0x27},
 	{MAX98373_R2016_THERM_HYSTERESIS, 0x01},
 	{MAX98373_R2017_THERM_FOLDBACK_SET, 0xC0},
 	{MAX98373_R2018_THERM_FOLDBACK_EN, 0x00},
 	{MAX98373_R201E_PIN_DRIVE_STRENGTH, 0x55},
 	{MAX98373_R2020_PCM_TX_HIZ_EN_1, 0xFE},
 	{MAX98373_R2021_PCM_TX_HIZ_EN_2, 0xFF},
 	{MAX98373_R2022_PCM_TX_SRC_1, 0x00},
 	{MAX98373_R2023_PCM_TX_SRC_2, 0x00},
 	{MAX98373_R2024_PCM_DATA_FMT_CFG, 0xC0},
 	{MAX98373_R2025_AUDIO_IF_MODE, 0x00},
 	{MAX98373_R2026_PCM_CLOCK_RATIO, 0x04},
 	{MAX98373_R2027_PCM_SR_SETUP_1, 0x08},
 	{MAX98373_R2028_PCM_SR_SETUP_2, 0x88},
 	{MAX98373_R2029_PCM_TO_SPK_MONO_MIX_1, 0x00},
 	{MAX98373_R202A_PCM_TO_SPK_MONO_MIX_2, 0x00},
 	{MAX98373_R202B_PCM_RX_EN, 0x00},
 	{MAX98373_R202C_PCM_TX_EN, 0x00},
 	{MAX98373_R202E_ICC_RX_CH_EN_1, 0x00},
 	{MAX98373_R202F_ICC_RX_CH_EN_2, 0x00},
 	{MAX98373_R2030_ICC_TX_HIZ_EN_1, 0xFF},
 	{MAX98373_R2031_ICC_TX_HIZ_EN_2, 0xFF},
 	{MAX98373_R2032_ICC_LINK_EN_CFG, 0x30},
 	{MAX98373_R2034_ICC_TX_CNTL, 0x00},
 	{MAX98373_R2035_ICC_TX_EN, 0x00},
 	{MAX98373_R2036_SOUNDWIRE_CTRL, 0x05},
 	{MAX98373_R203D_AMP_DIG_VOL_CTRL, 0x00},
 	{MAX98373_R203E_AMP_PATH_GAIN, 0x08},
 	{MAX98373_R203F_AMP_DSP_CFG, 0x02},
 	{MAX98373_R2040_TONE_GEN_CFG, 0x00},
 	{MAX98373_R2041_AMP_CFG, 0x03},
 	{MAX98373_R2042_AMP_EDGE_RATE_CFG, 0x00},
 	{MAX98373_R2043_AMP_EN, 0x00},
 	{MAX98373_R2046_IV_SENSE_ADC_DSP_CFG, 0x04},
 	{MAX98373_R2047_IV_SENSE_ADC_EN, 0x00},
 	{MAX98373_R2051_MEAS_ADC_SAMPLING_RATE, 0x00},
 	{MAX98373_R2052_MEAS_ADC_PVDD_FLT_CFG, 0x00},
 	{MAX98373_R2053_MEAS_ADC_THERM_FLT_CFG, 0x00},
 	{MAX98373_R2054_MEAS_ADC_PVDD_CH_READBACK, 0x00},
 	{MAX98373_R2055_MEAS_ADC_THERM_CH_READBACK, 0x00},
 	{MAX98373_R2056_MEAS_ADC_PVDD_CH_EN, 0x00},
 	{MAX98373_R2090_BDE_LVL_HOLD, 0x00},
 	{MAX98373_R2091_BDE_GAIN_ATK_REL_RATE, 0x00},
 	{MAX98373_R2092_BDE_CLIPPER_MODE, 0x00},
 	{MAX98373_R2097_BDE_L1_THRESH, 0x00},
 	{MAX98373_R2098_BDE_L2_THRESH, 0x00},
 	{MAX98373_R2099_BDE_L3_THRESH, 0x00},
 	{MAX98373_R209A_BDE_L4_THRESH, 0x00},
 	{MAX98373_R209B_BDE_THRESH_HYST, 0x00},
 	{MAX98373_R20A8_BDE_L1_CFG_1, 0x00},
 	{MAX98373_R20A9_BDE_L1_CFG_2, 0x00},
 	{MAX98373_R20AA_BDE_L1_CFG_3, 0x00},
 	{MAX98373_R20AB_BDE_L2_CFG_1, 0x00},
 	{MAX98373_R20AC_BDE_L2_CFG_2, 0x00},
 	{MAX98373_R20AD_BDE_L2_CFG_3, 0x00},
 	{MAX98373_R20AE_BDE_L3_CFG_1, 0x00},
 	{MAX98373_R20AF_BDE_L3_CFG_2, 0x00},
 	{MAX98373_R20B0_BDE_L3_CFG_3, 0x00},
 	{MAX98373_R20B1_BDE_L4_CFG_1, 0x00},
 	{MAX98373_R20B2_BDE_L4_CFG_2, 0x00},
 	{MAX98373_R20B3_BDE_L4_CFG_3, 0x00},
 	{MAX98373_R20B4_BDE_INFINITE_HOLD_RELEASE, 0x00},
 	{MAX98373_R20B5_BDE_EN, 0x00},
 	{MAX98373_R20B6_BDE_CUR_STATE_READBACK, 0x00},
 	{MAX98373_R20D1_DHT_CFG, 0x01},
 	{MAX98373_R20D2_DHT_ATTACK_CFG, 0x02},
 	{MAX98373_R20D3_DHT_RELEASE_CFG, 0x03},
 	{MAX98373_R20D4_DHT_EN, 0x00},
 	{MAX98373_R20E0_LIMITER_THRESH_CFG, 0x00},
 	{MAX98373_R20E1_LIMITER_ATK_REL_RATES, 0x00},
 	{MAX98373_R20E2_LIMITER_EN, 0x00},
 	{MAX98373_R20FE_DEVICE_AUTO_RESTART_CFG, 0x00},
 	{MAX98373_R20FF_GLOBAL_SHDN, 0x00},
 	{MAX98373_R21FF_REV_ID, 0x42},
 };

 static int max98373_dai_set_fmt(struct snd_soc_dai *codec_dai, unsigned int fmt)
 {
 	struct snd_soc_component *component = codec_dai->component;
 	struct max98373_priv *max98373 = snd_soc_component_get_drvdata(component);
 	unsigned int format = 0;
 	unsigned int invert = 0;

 	dev_dbg(component->dev, "%s: fmt 0x%08X\n", __func__, fmt);

 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
 	case SND_SOC_DAIFMT_NB_NF:
 		break;
 	case SND_SOC_DAIFMT_IB_NF:
 		invert = MAX98373_PCM_MODE_CFG_PCM_BCLKEDGE;
 		break;
 	default:
 		dev_err(component->dev, "DAI invert mode unsupported\n");
 		return -EINVAL;
 	}

 	regmap_update_bits(max98373->regmap,
 			   MAX98373_R2026_PCM_CLOCK_RATIO,
 			   MAX98373_PCM_MODE_CFG_PCM_BCLKEDGE,
 			   invert);

 	/* interface format */
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_I2S:
 		format = MAX98373_PCM_FORMAT_I2S;
 		break;
 	case SND_SOC_DAIFMT_LEFT_J:
 		format = MAX98373_PCM_FORMAT_LJ;
 		break;
 	case SND_SOC_DAIFMT_DSP_A:
 		format = MAX98373_PCM_FORMAT_TDM_MODE1;
 		break;
 	case SND_SOC_DAIFMT_DSP_B:
 		format = MAX98373_PCM_FORMAT_TDM_MODE0;
 		break;
 	default:
 		return -EINVAL;
 	}

 	regmap_update_bits(max98373->regmap,
 			   MAX98373_R2024_PCM_DATA_FMT_CFG,
 			   MAX98373_PCM_MODE_CFG_FORMAT_MASK,
 			   format << MAX98373_PCM_MODE_CFG_FORMAT_SHIFT);

 	return 0;
 }

 /* BCLKs per LRCLK */
 static const int bclk_sel_table[] = {
 	32, 48, 64, 96, 128, 192, 256, 384, 512, 320,
 };

 static int max98373_get_bclk_sel(int bclk)
 {
 	int i;
 	/* match BCLKs per LRCLK */
 	for (i = 0; i < ARRAY_SIZE(bclk_sel_table); i++) {
 		if (bclk_sel_table[i] == bclk)
 			return i + 2;
 	}
 	return 0;
 }

 static int max98373_set_clock(struct snd_soc_component *component,
 			      struct snd_pcm_hw_params *params)
 {
 	struct max98373_priv *max98373 = snd_soc_component_get_drvdata(component);
 	/* BCLK/LRCLK ratio calculation */
 	int blr_clk_ratio = params_channels(params) * max98373->ch_size;
 	int value;

 	if (!max98373->tdm_mode) {
 		/* BCLK configuration */
 		value = max98373_get_bclk_sel(blr_clk_ratio);
 		if (!value) {
 			dev_err(component->dev, "format unsupported %d\n",
 				params_format(params));
 			return -EINVAL;
 		}

 		regmap_update_bits(max98373->regmap,
 				   MAX98373_R2026_PCM_CLOCK_RATIO,
 				   MAX98373_PCM_CLK_SETUP_BSEL_MASK,
 				   value);
 	}
 	return 0;
 }

 static int max98373_dai_hw_params(struct snd_pcm_substream *substream,
 				  struct snd_pcm_hw_params *params,
 				  struct snd_soc_dai *dai)
 {
 	struct snd_soc_component *component = dai->component;
 	struct max98373_priv *max98373 = snd_soc_component_get_drvdata(component);
 	unsigned int sampling_rate = 0;
 	unsigned int chan_sz = 0;

 	/* pcm mode configuration */
 	switch (snd_pcm_format_width(params_format(params))) {
 	case 16:
 		chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_16;
 		break;
 	case 24:
 		chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_24;
 		break;
 	case 32:
 		chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_32;
 		break;
 	default:
 		dev_err(component->dev, "format unsupported %d\n",
 			params_format(params));
 		goto err;
 	}

 	max98373->ch_size = snd_pcm_format_width(params_format(params));

 	regmap_update_bits(max98373->regmap,
 			   MAX98373_R2024_PCM_DATA_FMT_CFG,
 			   MAX98373_PCM_MODE_CFG_CHANSZ_MASK, chan_sz);

 	dev_dbg(component->dev, "format supported %d",
 		params_format(params));

 	/* sampling rate configuration */
 	switch (params_rate(params)) {
 	case 8000:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_8000;
 		break;
 	case 11025:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_11025;
 		break;
 	case 12000:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_12000;
 		break;
 	case 16000:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_16000;
 		break;
 	case 22050:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_22050;
 		break;
 	case 24000:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_24000;
 		break;
 	case 32000:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_32000;
 		break;
 	case 44100:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_44100;
 		break;
 	case 48000:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_48000;
 		break;
 	case 88200:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_88200;
 		break;
 	case 96000:
 		sampling_rate = MAX98373_PCM_SR_SET1_SR_96000;
 		break;
 	default:
 		dev_err(component->dev, "rate %d not supported\n",
 			params_rate(params));
 		goto err;
 	}

 	/* set DAI_SR to correct LRCLK frequency */
 	regmap_update_bits(max98373->regmap,
 			   MAX98373_R2027_PCM_SR_SETUP_1,
 			   MAX98373_PCM_SR_SET1_SR_MASK,
 			   sampling_rate);
 	regmap_update_bits(max98373->regmap,
 			   MAX98373_R2028_PCM_SR_SETUP_2,
 			   MAX98373_PCM_SR_SET2_SR_MASK,
 			   sampling_rate << MAX98373_PCM_SR_SET2_SR_SHIFT);

 	/* set sampling rate of IV */
 	if (max98373->interleave_mode &&
 	    sampling_rate > MAX98373_PCM_SR_SET1_SR_16000)
 		regmap_update_bits(max98373->regmap,
 				   MAX98373_R2028_PCM_SR_SETUP_2,
 				   MAX98373_PCM_SR_SET2_IVADC_SR_MASK,
 				   sampling_rate - 3);
 	else
 		regmap_update_bits(max98373->regmap,
 				   MAX98373_R2028_PCM_SR_SETUP_2,
 				   MAX98373_PCM_SR_SET2_IVADC_SR_MASK,
 				   sampling_rate);

 	return max98373_set_clock(component, params);
 err:
 	return -EINVAL;
 }

 static int max98373_dai_tdm_slot(struct snd_soc_dai *dai,
 				 unsigned int tx_mask, unsigned int rx_mask,
 				 int slots, int slot_width)
 {
 	struct snd_soc_component *component = dai->component;
 	struct max98373_priv *max98373 = snd_soc_component_get_drvdata(component);
 	int bsel = 0;
 	unsigned int chan_sz = 0;
 	unsigned int mask;
 	int x, slot_found;

 	if (!tx_mask && !rx_mask && !slots && !slot_width)
 		max98373->tdm_mode = false;
 	else
 		max98373->tdm_mode = true;

 	/* BCLK configuration */
 	bsel = max98373_get_bclk_sel(slots * slot_width);
 	if (bsel == 0) {
 		dev_err(component->dev, "BCLK %d not supported\n",
 			slots * slot_width);
 		return -EINVAL;
 	}

 	regmap_update_bits(max98373->regmap,
 			   MAX98373_R2026_PCM_CLOCK_RATIO,
 			   MAX98373_PCM_CLK_SETUP_BSEL_MASK,
 			   bsel);

 	/* Channel size configuration */
 	switch (slot_width) {
 	case 16:
 		chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_16;
 		break;
 	case 24:
 		chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_24;
 		break;
 	case 32:
 		chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_32;
 		break;
 	default:
 		dev_err(component->dev, "format unsupported %d\n",
 			slot_width);
 		return -EINVAL;
 	}

 	regmap_update_bits(max98373->regmap,
 			   MAX98373_R2024_PCM_DATA_FMT_CFG,
 			   MAX98373_PCM_MODE_CFG_CHANSZ_MASK, chan_sz);

 	/* Rx slot configuration */
 	slot_found = 0;
 	mask = rx_mask;
 	for (x = 0 ; x < 16 ; x++, mask >>= 1) {
 		if (mask & 0x1) {
 			if (slot_found == 0)
 				regmap_update_bits(max98373->regmap,
 						   MAX98373_R2029_PCM_TO_SPK_MONO_MIX_1,
 						   MAX98373_PCM_TO_SPK_CH0_SRC_MASK, x);
 			else
 				regmap_write(max98373->regmap,
 					     MAX98373_R202A_PCM_TO_SPK_MONO_MIX_2,
 					     x);
 			slot_found++;
 			if (slot_found > 1)
 				break;
 		}
 	}

 	/* Tx slot Hi-Z configuration */
 	regmap_write(max98373->regmap,
 		     MAX98373_R2020_PCM_TX_HIZ_EN_1,
 		     ~tx_mask & 0xFF);
 	regmap_write(max98373->regmap,
 		     MAX98373_R2021_PCM_TX_HIZ_EN_2,
 		     (~tx_mask & 0xFF00) >> 8);

 	return 0;
 }

 #define MAX98373_RATES SNDRV_PCM_RATE_8000_96000

 #define MAX98373_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | \
 	SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)

 static const struct snd_soc_dai_ops max98373_dai_ops = {
 	.set_fmt = max98373_dai_set_fmt,
 	.hw_params = max98373_dai_hw_params,
 	.set_tdm_slot = max98373_dai_tdm_slot,
 };

 static bool max98373_readable_register(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case MAX98373_R2000_SW_RESET:
 	case MAX98373_R2001_INT_RAW1 ... MAX98373_R200C_INT_EN3:
 	case MAX98373_R2010_IRQ_CTRL:
 	case MAX98373_R2014_THERM_WARN_THRESH
 		... MAX98373_R2018_THERM_FOLDBACK_EN:
 	case MAX98373_R201E_PIN_DRIVE_STRENGTH
 		... MAX98373_R2036_SOUNDWIRE_CTRL:
 	case MAX98373_R203D_AMP_DIG_VOL_CTRL ... MAX98373_R2043_AMP_EN:
 	case MAX98373_R2046_IV_SENSE_ADC_DSP_CFG
 		... MAX98373_R2047_IV_SENSE_ADC_EN:
 	case MAX98373_R2051_MEAS_ADC_SAMPLING_RATE
 		... MAX98373_R2056_MEAS_ADC_PVDD_CH_EN:
 	case MAX98373_R2090_BDE_LVL_HOLD ... MAX98373_R2092_BDE_CLIPPER_MODE:
 	case MAX98373_R2097_BDE_L1_THRESH
 		... MAX98373_R209B_BDE_THRESH_HYST:
 	case MAX98373_R20A8_BDE_L1_CFG_1 ... MAX98373_R20B3_BDE_L4_CFG_3:
 	case MAX98373_R20B5_BDE_EN ... MAX98373_R20B6_BDE_CUR_STATE_READBACK:
 	case MAX98373_R20D1_DHT_CFG ... MAX98373_R20D4_DHT_EN:
 	case MAX98373_R20E0_LIMITER_THRESH_CFG ... MAX98373_R20E2_LIMITER_EN:
 	case MAX98373_R20FE_DEVICE_AUTO_RESTART_CFG
 		... MAX98373_R20FF_GLOBAL_SHDN:
 	case MAX98373_R21FF_REV_ID:
 		return true;
 	default:
 		return false;
 	}
 };

 static bool max98373_volatile_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case MAX98373_R2000_SW_RESET ... MAX98373_R2009_INT_FLAG3:
 	case MAX98373_R2054_MEAS_ADC_PVDD_CH_READBACK:
 	case MAX98373_R2055_MEAS_ADC_THERM_CH_READBACK:
 	case MAX98373_R20B6_BDE_CUR_STATE_READBACK:
 	case MAX98373_R20FF_GLOBAL_SHDN:
 	case MAX98373_R21FF_REV_ID:
 		return true;
 	default:
 		return false;
 	}
 }

 static struct snd_soc_dai_driver max98373_dai[] = {
 	{
 		.name = "max98373-aif1",
 		.playback = {
 			.stream_name = "HiFi Playback",
 			.channels_min = 1,
 			.channels_max = 2,
 			.rates = MAX98373_RATES,
 			.formats = MAX98373_FORMATS,
 		},
 		.capture = {
 			.stream_name = "HiFi Capture",
 			.channels_min = 1,
 			.channels_max = 2,
 			.rates = MAX98373_RATES,
 			.formats = MAX98373_FORMATS,
 		},
 		.ops = &max98373_dai_ops,
 	}
 };

 #ifdef CONFIG_PM_SLEEP
 static int max98373_suspend(struct device *dev)
 {
 	struct max98373_priv *max98373 = dev_get_drvdata(dev);
 	int i;

 	/* cache feedback register values before suspend */
 	for (i = 0; i < max98373->cache_num; i++)
 		regmap_read(max98373->regmap, max98373->cache[i].reg, &max98373->cache[i].val);

 	regcache_cache_only(max98373->regmap, true);
 	regcache_mark_dirty(max98373->regmap);
 	return 0;
 }

 static int max98373_resume(struct device *dev)
 {
 	struct max98373_priv *max98373 = dev_get_drvdata(dev);

 	regcache_cache_only(max98373->regmap, false);
 	max98373_reset(max98373, dev);
 	regcache_sync(max98373->regmap);
 	return 0;
 }
 #endif

 static const struct dev_pm_ops max98373_pm = {
 	SET_SYSTEM_SLEEP_PM_OPS(max98373_suspend, max98373_resume)
 };

 static const struct regmap_config max98373_regmap = {
 	.reg_bits = 16,
 	.val_bits = 8,
 	.max_register = MAX98373_R21FF_REV_ID,
 	.reg_defaults  = max98373_reg,
 	.num_reg_defaults = ARRAY_SIZE(max98373_reg),
 	.readable_reg = max98373_readable_register,
 	.volatile_reg = max98373_volatile_reg,
 	.cache_type = REGCACHE_RBTREE,
 };

 static int max98373_i2c_probe(struct i2c_client *i2c)
 {
 	int ret = 0;
 	int reg = 0;
 	int i;
 	struct max98373_priv *max98373 = NULL;

 	max98373 = devm_kzalloc(&i2c->dev, sizeof(*max98373), GFP_KERNEL);

 	if (!max98373) {
 		ret = -ENOMEM;
 		return ret;
 	}
 	i2c_set_clientdata(i2c, max98373);

 	/* update interleave mode info */
 	if (device_property_read_bool(&i2c->dev, "maxim,interleave_mode"))
 		max98373->interleave_mode = true;
 	else
 		max98373->interleave_mode = false;

 	/* regmap initialization */
 	max98373->regmap = devm_regmap_init_i2c(i2c, &max98373_regmap);
 	if (IS_ERR(max98373->regmap)) {
 		ret = PTR_ERR(max98373->regmap);
 		dev_err(&i2c->dev,
 			"Failed to allocate regmap: %d\n", ret);
 		return ret;
 	}

 	max98373->cache_num = ARRAY_SIZE(max98373_i2c_cache_reg);
 	max98373->cache = devm_kcalloc(&i2c->dev, max98373->cache_num,
 				       sizeof(*max98373->cache),
 				       GFP_KERNEL);
 	if (!max98373->cache) {
 		ret = -ENOMEM;
 		return ret;
 	}

 	for (i = 0; i < max98373->cache_num; i++)
 		max98373->cache[i].reg = max98373_i2c_cache_reg[i];

 	/* voltage/current slot & gpio configuration */
 	max98373_slot_config(&i2c->dev, max98373);

 	/* Power on device */
 	if (gpio_is_valid(max98373->reset_gpio)) {
 		ret = devm_gpio_request(&i2c->dev, max98373->reset_gpio,
 					"MAX98373_RESET");
 		if (ret) {
 			dev_err(&i2c->dev, "%s: Failed to request gpio %d\n",
 				__func__, max98373->reset_gpio);
 			return -EINVAL;
 		}
 		gpio_direction_output(max98373->reset_gpio, 0);
 		msleep(50);
 		gpio_direction_output(max98373->reset_gpio, 1);
 		msleep(20);
 	}

 	/* Check Revision ID */
 	ret = regmap_read(max98373->regmap,
 			  MAX98373_R21FF_REV_ID, &reg);
 	if (ret < 0) {
 		dev_err(&i2c->dev,
 			"Failed to read: 0x%02X\n", MAX98373_R21FF_REV_ID);
 		return ret;
 	}
 	dev_info(&i2c->dev, "MAX98373 revisionID: 0x%02X\n", reg);

 	/* codec registration */
 	ret = devm_snd_soc_register_component(&i2c->dev, &soc_codec_dev_max98373,
 					      max98373_dai, ARRAY_SIZE(max98373_dai));
 	if (ret < 0)
 		dev_err(&i2c->dev, "Failed to register codec: %d\n", ret);

 	return ret;
 }

 static const struct i2c_device_id max98373_i2c_id[] = {
 	{ "max98373", 0},
 	{ },
 };

 MODULE_DEVICE_TABLE(i2c, max98373_i2c_id);

 #if defined(CONFIG_OF)
 static const struct of_device_id max98373_of_match[] = {
 	{ .compatible = "maxim,max98373", },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, max98373_of_match);
 #endif

 #ifdef CONFIG_ACPI
 static const struct acpi_device_id max98373_acpi_match[] = {
 	{ "MX98373", 0 },
 	{},
 };
 MODULE_DEVICE_TABLE(acpi, max98373_acpi_match);
 #endif

 static struct i2c_driver max98373_i2c_driver = {
 	.driver = {
 		.name = "max98373",
 		.of_match_table = of_match_ptr(max98373_of_match),
 		.acpi_match_table = ACPI_PTR(max98373_acpi_match),
 		.pm = &max98373_pm,
 	},
 	.probe = max98373_i2c_probe,
 	.id_table = max98373_i2c_id,
 };

 module_i2c_driver(max98373_i2c_driver)

 MODULE_DESCRIPTION("ALSA SoC MAX98373 driver");
 MODULE_AUTHOR("Ryan Lee <ryans.lee@maximintegrated.com>");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0
	// Copyright (c) 2017, Maxim Integrated

	#include <linux/acpi.h>
	#include <linux/delay.h>
	#include <linux/gpio.h>
	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/mod_devicetable.h>
	#include <linux/of.h>
	#include <linux/of_gpio.h>
	#include <linux/pm.h>
	#include <linux/regmap.h>
	#include <linux/slab.h>
	#include <linux/cdev.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include <sound/soc.h>
	#include <sound/tlv.h>
	#include "max98373.h"

	static const u32 max98373_i2c_cache_reg[] = {
	MAX98373_R2054_MEAS_ADC_PVDD_CH_READBACK,
	MAX98373_R2055_MEAS_ADC_THERM_CH_READBACK,
	MAX98373_R20B6_BDE_CUR_STATE_READBACK,
	};

	static struct reg_default max98373_reg[] = {
	{MAX98373_R2000_SW_RESET, 0x00},
	{MAX98373_R2001_INT_RAW1, 0x00},
	{MAX98373_R2002_INT_RAW2, 0x00},
	{MAX98373_R2003_INT_RAW3, 0x00},
	{MAX98373_R2004_INT_STATE1, 0x00},
	{MAX98373_R2005_INT_STATE2, 0x00},
	{MAX98373_R2006_INT_STATE3, 0x00},
	{MAX98373_R2007_INT_FLAG1, 0x00},
	{MAX98373_R2008_INT_FLAG2, 0x00},
	{MAX98373_R2009_INT_FLAG3, 0x00},
	{MAX98373_R200A_INT_EN1, 0x00},
	{MAX98373_R200B_INT_EN2, 0x00},
	{MAX98373_R200C_INT_EN3, 0x00},
	{MAX98373_R200D_INT_FLAG_CLR1, 0x00},
	{MAX98373_R200E_INT_FLAG_CLR2, 0x00},
	{MAX98373_R200F_INT_FLAG_CLR3, 0x00},
	{MAX98373_R2010_IRQ_CTRL, 0x00},
	{MAX98373_R2014_THERM_WARN_THRESH, 0x10},
	{MAX98373_R2015_THERM_SHDN_THRESH, 0x27},
	{MAX98373_R2016_THERM_HYSTERESIS, 0x01},
	{MAX98373_R2017_THERM_FOLDBACK_SET, 0xC0},
	{MAX98373_R2018_THERM_FOLDBACK_EN, 0x00},
	{MAX98373_R201E_PIN_DRIVE_STRENGTH, 0x55},
	{MAX98373_R2020_PCM_TX_HIZ_EN_1, 0xFE},
	{MAX98373_R2021_PCM_TX_HIZ_EN_2, 0xFF},
	{MAX98373_R2022_PCM_TX_SRC_1, 0x00},
	{MAX98373_R2023_PCM_TX_SRC_2, 0x00},
	{MAX98373_R2024_PCM_DATA_FMT_CFG, 0xC0},
	{MAX98373_R2025_AUDIO_IF_MODE, 0x00},
	{MAX98373_R2026_PCM_CLOCK_RATIO, 0x04},
	{MAX98373_R2027_PCM_SR_SETUP_1, 0x08},
	{MAX98373_R2028_PCM_SR_SETUP_2, 0x88},
	{MAX98373_R2029_PCM_TO_SPK_MONO_MIX_1, 0x00},
	{MAX98373_R202A_PCM_TO_SPK_MONO_MIX_2, 0x00},
	{MAX98373_R202B_PCM_RX_EN, 0x00},
	{MAX98373_R202C_PCM_TX_EN, 0x00},
	{MAX98373_R202E_ICC_RX_CH_EN_1, 0x00},
	{MAX98373_R202F_ICC_RX_CH_EN_2, 0x00},
	{MAX98373_R2030_ICC_TX_HIZ_EN_1, 0xFF},
	{MAX98373_R2031_ICC_TX_HIZ_EN_2, 0xFF},
	{MAX98373_R2032_ICC_LINK_EN_CFG, 0x30},
	{MAX98373_R2034_ICC_TX_CNTL, 0x00},
	{MAX98373_R2035_ICC_TX_EN, 0x00},
	{MAX98373_R2036_SOUNDWIRE_CTRL, 0x05},
	{MAX98373_R203D_AMP_DIG_VOL_CTRL, 0x00},
	{MAX98373_R203E_AMP_PATH_GAIN, 0x08},
	{MAX98373_R203F_AMP_DSP_CFG, 0x02},
	{MAX98373_R2040_TONE_GEN_CFG, 0x00},
	{MAX98373_R2041_AMP_CFG, 0x03},
	{MAX98373_R2042_AMP_EDGE_RATE_CFG, 0x00},
	{MAX98373_R2043_AMP_EN, 0x00},
	{MAX98373_R2046_IV_SENSE_ADC_DSP_CFG, 0x04},
	{MAX98373_R2047_IV_SENSE_ADC_EN, 0x00},
	{MAX98373_R2051_MEAS_ADC_SAMPLING_RATE, 0x00},
	{MAX98373_R2052_MEAS_ADC_PVDD_FLT_CFG, 0x00},
	{MAX98373_R2053_MEAS_ADC_THERM_FLT_CFG, 0x00},
	{MAX98373_R2054_MEAS_ADC_PVDD_CH_READBACK, 0x00},
	{MAX98373_R2055_MEAS_ADC_THERM_CH_READBACK, 0x00},
	{MAX98373_R2056_MEAS_ADC_PVDD_CH_EN, 0x00},
	{MAX98373_R2090_BDE_LVL_HOLD, 0x00},
	{MAX98373_R2091_BDE_GAIN_ATK_REL_RATE, 0x00},
	{MAX98373_R2092_BDE_CLIPPER_MODE, 0x00},
	{MAX98373_R2097_BDE_L1_THRESH, 0x00},
	{MAX98373_R2098_BDE_L2_THRESH, 0x00},
	{MAX98373_R2099_BDE_L3_THRESH, 0x00},
	{MAX98373_R209A_BDE_L4_THRESH, 0x00},
	{MAX98373_R209B_BDE_THRESH_HYST, 0x00},
	{MAX98373_R20A8_BDE_L1_CFG_1, 0x00},
	{MAX98373_R20A9_BDE_L1_CFG_2, 0x00},
	{MAX98373_R20AA_BDE_L1_CFG_3, 0x00},
	{MAX98373_R20AB_BDE_L2_CFG_1, 0x00},
	{MAX98373_R20AC_BDE_L2_CFG_2, 0x00},
	{MAX98373_R20AD_BDE_L2_CFG_3, 0x00},
	{MAX98373_R20AE_BDE_L3_CFG_1, 0x00},
	{MAX98373_R20AF_BDE_L3_CFG_2, 0x00},
	{MAX98373_R20B0_BDE_L3_CFG_3, 0x00},
	{MAX98373_R20B1_BDE_L4_CFG_1, 0x00},
	{MAX98373_R20B2_BDE_L4_CFG_2, 0x00},
	{MAX98373_R20B3_BDE_L4_CFG_3, 0x00},
	{MAX98373_R20B4_BDE_INFINITE_HOLD_RELEASE, 0x00},
	{MAX98373_R20B5_BDE_EN, 0x00},
	{MAX98373_R20B6_BDE_CUR_STATE_READBACK, 0x00},
	{MAX98373_R20D1_DHT_CFG, 0x01},
	{MAX98373_R20D2_DHT_ATTACK_CFG, 0x02},
	{MAX98373_R20D3_DHT_RELEASE_CFG, 0x03},
	{MAX98373_R20D4_DHT_EN, 0x00},
	{MAX98373_R20E0_LIMITER_THRESH_CFG, 0x00},
	{MAX98373_R20E1_LIMITER_ATK_REL_RATES, 0x00},
	{MAX98373_R20E2_LIMITER_EN, 0x00},
	{MAX98373_R20FE_DEVICE_AUTO_RESTART_CFG, 0x00},
	{MAX98373_R20FF_GLOBAL_SHDN, 0x00},
	{MAX98373_R21FF_REV_ID, 0x42},
	};

	static int max98373_dai_set_fmt(struct snd_soc_dai *codec_dai, unsigned int fmt)
	{
	struct snd_soc_component *component = codec_dai->component;
	struct max98373_priv *max98373 = snd_soc_component_get_drvdata(component);
	unsigned int format = 0;
	unsigned int invert = 0;

	dev_dbg(component->dev, "%s: fmt 0x%08X\n", __func__, fmt);

	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
	case SND_SOC_DAIFMT_NB_NF:
	break;
	case SND_SOC_DAIFMT_IB_NF:
	invert = MAX98373_PCM_MODE_CFG_PCM_BCLKEDGE;
	break;
	default:
	dev_err(component->dev, "DAI invert mode unsupported\n");
	return -EINVAL;
	}

	regmap_update_bits(max98373->regmap,
	MAX98373_R2026_PCM_CLOCK_RATIO,
	MAX98373_PCM_MODE_CFG_PCM_BCLKEDGE,
	invert);

	/* interface format */
	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
	format = MAX98373_PCM_FORMAT_I2S;
	break;
	case SND_SOC_DAIFMT_LEFT_J:
	format = MAX98373_PCM_FORMAT_LJ;
	break;
	case SND_SOC_DAIFMT_DSP_A:
	format = MAX98373_PCM_FORMAT_TDM_MODE1;
	break;
	case SND_SOC_DAIFMT_DSP_B:
	format = MAX98373_PCM_FORMAT_TDM_MODE0;
	break;
	default:
	return -EINVAL;
	}

	regmap_update_bits(max98373->regmap,
	MAX98373_R2024_PCM_DATA_FMT_CFG,
	MAX98373_PCM_MODE_CFG_FORMAT_MASK,
	format << MAX98373_PCM_MODE_CFG_FORMAT_SHIFT);

	return 0;
	}

	/* BCLKs per LRCLK */
	static const int bclk_sel_table[] = {
	32, 48, 64, 96, 128, 192, 256, 384, 512, 320,
	};

	static int max98373_get_bclk_sel(int bclk)
	{
	int i;
	/* match BCLKs per LRCLK */
	for (i = 0; i < ARRAY_SIZE(bclk_sel_table); i++) {
	if (bclk_sel_table[i] == bclk)
	return i + 2;
	}
	return 0;
	}

	static int max98373_set_clock(struct snd_soc_component *component,
	struct snd_pcm_hw_params *params)
	{
	struct max98373_priv *max98373 = snd_soc_component_get_drvdata(component);
	/* BCLK/LRCLK ratio calculation */
	int blr_clk_ratio = params_channels(params) * max98373->ch_size;
	int value;

	if (!max98373->tdm_mode) {
	/* BCLK configuration */
	value = max98373_get_bclk_sel(blr_clk_ratio);
	if (!value) {
	dev_err(component->dev, "format unsupported %d\n",
	params_format(params));
	return -EINVAL;
	}

	regmap_update_bits(max98373->regmap,
	MAX98373_R2026_PCM_CLOCK_RATIO,
	MAX98373_PCM_CLK_SETUP_BSEL_MASK,
	value);
	}
	return 0;
	}

	static int max98373_dai_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params,
	struct snd_soc_dai *dai)
	{
	struct snd_soc_component *component = dai->component;
	struct max98373_priv *max98373 = snd_soc_component_get_drvdata(component);
	unsigned int sampling_rate = 0;
	unsigned int chan_sz = 0;

	/* pcm mode configuration */
	switch (snd_pcm_format_width(params_format(params))) {
	case 16:
	chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_16;
	break;
	case 24:
	chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_24;
	break;
	case 32:
	chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_32;
	break;
	default:
	dev_err(component->dev, "format unsupported %d\n",
	params_format(params));
	goto err;
	}

	max98373->ch_size = snd_pcm_format_width(params_format(params));

	regmap_update_bits(max98373->regmap,
	MAX98373_R2024_PCM_DATA_FMT_CFG,
	MAX98373_PCM_MODE_CFG_CHANSZ_MASK, chan_sz);

	dev_dbg(component->dev, "format supported %d",
	params_format(params));

	/* sampling rate configuration */
	switch (params_rate(params)) {
	case 8000:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_8000;
	break;
	case 11025:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_11025;
	break;
	case 12000:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_12000;
	break;
	case 16000:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_16000;
	break;
	case 22050:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_22050;
	break;
	case 24000:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_24000;
	break;
	case 32000:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_32000;
	break;
	case 44100:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_44100;
	break;
	case 48000:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_48000;
	break;
	case 88200:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_88200;
	break;
	case 96000:
	sampling_rate = MAX98373_PCM_SR_SET1_SR_96000;
	break;
	default:
	dev_err(component->dev, "rate %d not supported\n",
	params_rate(params));
	goto err;
	}

	/* set DAI_SR to correct LRCLK frequency */
	regmap_update_bits(max98373->regmap,
	MAX98373_R2027_PCM_SR_SETUP_1,
	MAX98373_PCM_SR_SET1_SR_MASK,
	sampling_rate);
	regmap_update_bits(max98373->regmap,
	MAX98373_R2028_PCM_SR_SETUP_2,
	MAX98373_PCM_SR_SET2_SR_MASK,
	sampling_rate << MAX98373_PCM_SR_SET2_SR_SHIFT);

	/* set sampling rate of IV */
	if (max98373->interleave_mode &&
	sampling_rate > MAX98373_PCM_SR_SET1_SR_16000)
	regmap_update_bits(max98373->regmap,
	MAX98373_R2028_PCM_SR_SETUP_2,
	MAX98373_PCM_SR_SET2_IVADC_SR_MASK,
	sampling_rate - 3);
	else
	regmap_update_bits(max98373->regmap,
	MAX98373_R2028_PCM_SR_SETUP_2,
	MAX98373_PCM_SR_SET2_IVADC_SR_MASK,
	sampling_rate);

	return max98373_set_clock(component, params);
	err:
	return -EINVAL;
	}

	static int max98373_dai_tdm_slot(struct snd_soc_dai *dai,
	unsigned int tx_mask, unsigned int rx_mask,
	int slots, int slot_width)
	{
	struct snd_soc_component *component = dai->component;
	struct max98373_priv *max98373 = snd_soc_component_get_drvdata(component);
	int bsel = 0;
	unsigned int chan_sz = 0;
	unsigned int mask;
	int x, slot_found;

	if (!tx_mask && !rx_mask && !slots && !slot_width)
	max98373->tdm_mode = false;
	else
	max98373->tdm_mode = true;

	/* BCLK configuration */
	bsel = max98373_get_bclk_sel(slots * slot_width);
	if (bsel == 0) {
	dev_err(component->dev, "BCLK %d not supported\n",
	slots * slot_width);
	return -EINVAL;
	}

	regmap_update_bits(max98373->regmap,
	MAX98373_R2026_PCM_CLOCK_RATIO,
	MAX98373_PCM_CLK_SETUP_BSEL_MASK,
	bsel);

	/* Channel size configuration */
	switch (slot_width) {
	case 16:
	chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_16;
	break;
	case 24:
	chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_24;
	break;
	case 32:
	chan_sz = MAX98373_PCM_MODE_CFG_CHANSZ_32;
	break;
	default:
	dev_err(component->dev, "format unsupported %d\n",
	slot_width);
	return -EINVAL;
	}

	regmap_update_bits(max98373->regmap,
	MAX98373_R2024_PCM_DATA_FMT_CFG,
	MAX98373_PCM_MODE_CFG_CHANSZ_MASK, chan_sz);

	/* Rx slot configuration */
	slot_found = 0;
	mask = rx_mask;
	for (x = 0 ; x < 16 ; x++, mask >>= 1) {
	if (mask & 0x1) {
	if (slot_found == 0)
	regmap_update_bits(max98373->regmap,
	MAX98373_R2029_PCM_TO_SPK_MONO_MIX_1,
	MAX98373_PCM_TO_SPK_CH0_SRC_MASK, x);
	else
	regmap_write(max98373->regmap,
	MAX98373_R202A_PCM_TO_SPK_MONO_MIX_2,
	x);
	slot_found++;
	if (slot_found > 1)
	break;
	}
	}

	/* Tx slot Hi-Z configuration */
	regmap_write(max98373->regmap,
	MAX98373_R2020_PCM_TX_HIZ_EN_1,
	~tx_mask & 0xFF);
	regmap_write(max98373->regmap,
	MAX98373_R2021_PCM_TX_HIZ_EN_2,
	(~tx_mask & 0xFF00) >> 8);

	return 0;
	}

	#define MAX98373_RATES SNDRV_PCM_RATE_8000_96000

	#define MAX98373_FORMATS (SNDRV_PCM_FMTBIT_S16_LE \| \
	SNDRV_PCM_FMTBIT_S24_LE \| SNDRV_PCM_FMTBIT_S32_LE)

	static const struct snd_soc_dai_ops max98373_dai_ops = {
	.set_fmt = max98373_dai_set_fmt,
	.hw_params = max98373_dai_hw_params,
	.set_tdm_slot = max98373_dai_tdm_slot,
	};

	static bool max98373_readable_register(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case MAX98373_R2000_SW_RESET:
	case MAX98373_R2001_INT_RAW1 ... MAX98373_R200C_INT_EN3:
	case MAX98373_R2010_IRQ_CTRL:
	case MAX98373_R2014_THERM_WARN_THRESH
	... MAX98373_R2018_THERM_FOLDBACK_EN:
	case MAX98373_R201E_PIN_DRIVE_STRENGTH
	... MAX98373_R2036_SOUNDWIRE_CTRL:
	case MAX98373_R203D_AMP_DIG_VOL_CTRL ... MAX98373_R2043_AMP_EN:
	case MAX98373_R2046_IV_SENSE_ADC_DSP_CFG
	... MAX98373_R2047_IV_SENSE_ADC_EN:
	case MAX98373_R2051_MEAS_ADC_SAMPLING_RATE
	... MAX98373_R2056_MEAS_ADC_PVDD_CH_EN:
	case MAX98373_R2090_BDE_LVL_HOLD ... MAX98373_R2092_BDE_CLIPPER_MODE:
	case MAX98373_R2097_BDE_L1_THRESH
	... MAX98373_R209B_BDE_THRESH_HYST:
	case MAX98373_R20A8_BDE_L1_CFG_1 ... MAX98373_R20B3_BDE_L4_CFG_3:
	case MAX98373_R20B5_BDE_EN ... MAX98373_R20B6_BDE_CUR_STATE_READBACK:
	case MAX98373_R20D1_DHT_CFG ... MAX98373_R20D4_DHT_EN:
	case MAX98373_R20E0_LIMITER_THRESH_CFG ... MAX98373_R20E2_LIMITER_EN:
	case MAX98373_R20FE_DEVICE_AUTO_RESTART_CFG
	... MAX98373_R20FF_GLOBAL_SHDN:
	case MAX98373_R21FF_REV_ID:
	return true;
	default:
	return false;
	}
	};

	static bool max98373_volatile_reg(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case MAX98373_R2000_SW_RESET ... MAX98373_R2009_INT_FLAG3:
	case MAX98373_R2054_MEAS_ADC_PVDD_CH_READBACK:
	case MAX98373_R2055_MEAS_ADC_THERM_CH_READBACK:
	case MAX98373_R20B6_BDE_CUR_STATE_READBACK:
	case MAX98373_R20FF_GLOBAL_SHDN:
	case MAX98373_R21FF_REV_ID:
	return true;
	default:
	return false;
	}
	}

	static struct snd_soc_dai_driver max98373_dai[] = {
	{
	.name = "max98373-aif1",
	.playback = {
	.stream_name = "HiFi Playback",
	.channels_min = 1,
	.channels_max = 2,
	.rates = MAX98373_RATES,
	.formats = MAX98373_FORMATS,
	},
	.capture = {
	.stream_name = "HiFi Capture",
	.channels_min = 1,
	.channels_max = 2,
	.rates = MAX98373_RATES,
	.formats = MAX98373_FORMATS,
	},
	.ops = &max98373_dai_ops,
	}
	};

	#ifdef CONFIG_PM_SLEEP
	static int max98373_suspend(struct device *dev)
	{
	struct max98373_priv *max98373 = dev_get_drvdata(dev);
	int i;

	/* cache feedback register values before suspend */
	for (i = 0; i < max98373->cache_num; i++)
	regmap_read(max98373->regmap, max98373->cache[i].reg, &max98373->cache[i].val);

	regcache_cache_only(max98373->regmap, true);
	regcache_mark_dirty(max98373->regmap);
	return 0;
	}

	static int max98373_resume(struct device *dev)
	{
	struct max98373_priv *max98373 = dev_get_drvdata(dev);

	regcache_cache_only(max98373->regmap, false);
	max98373_reset(max98373, dev);
	regcache_sync(max98373->regmap);
	return 0;
	}
	#endif

	static const struct dev_pm_ops max98373_pm = {
	SET_SYSTEM_SLEEP_PM_OPS(max98373_suspend, max98373_resume)
	};

	static const struct regmap_config max98373_regmap = {
	.reg_bits = 16,
	.val_bits = 8,
	.max_register = MAX98373_R21FF_REV_ID,
	.reg_defaults = max98373_reg,
	.num_reg_defaults = ARRAY_SIZE(max98373_reg),
	.readable_reg = max98373_readable_register,
	.volatile_reg = max98373_volatile_reg,
	.cache_type = REGCACHE_RBTREE,
	};

	static int max98373_i2c_probe(struct i2c_client *i2c)
	{
	int ret = 0;
	int reg = 0;
	int i;
	struct max98373_priv *max98373 = NULL;

	max98373 = devm_kzalloc(&i2c->dev, sizeof(*max98373), GFP_KERNEL);

	if (!max98373) {
	ret = -ENOMEM;
	return ret;
	}
	i2c_set_clientdata(i2c, max98373);

	/* update interleave mode info */
	if (device_property_read_bool(&i2c->dev, "maxim,interleave_mode"))
	max98373->interleave_mode = true;
	else
	max98373->interleave_mode = false;

	/* regmap initialization */
	max98373->regmap = devm_regmap_init_i2c(i2c, &max98373_regmap);
	if (IS_ERR(max98373->regmap)) {
	ret = PTR_ERR(max98373->regmap);
	dev_err(&i2c->dev,
	"Failed to allocate regmap: %d\n", ret);
	return ret;
	}

	max98373->cache_num = ARRAY_SIZE(max98373_i2c_cache_reg);
	max98373->cache = devm_kcalloc(&i2c->dev, max98373->cache_num,
	sizeof(*max98373->cache),
	GFP_KERNEL);
	if (!max98373->cache) {
	ret = -ENOMEM;
	return ret;
	}

	for (i = 0; i < max98373->cache_num; i++)
	max98373->cache[i].reg = max98373_i2c_cache_reg[i];

	/* voltage/current slot & gpio configuration */
	max98373_slot_config(&i2c->dev, max98373);

	/* Power on device */
	if (gpio_is_valid(max98373->reset_gpio)) {
	ret = devm_gpio_request(&i2c->dev, max98373->reset_gpio,
	"MAX98373_RESET");
	if (ret) {
	dev_err(&i2c->dev, "%s: Failed to request gpio %d\n",
	__func__, max98373->reset_gpio);
	return -EINVAL;
	}
	gpio_direction_output(max98373->reset_gpio, 0);
	msleep(50);
	gpio_direction_output(max98373->reset_gpio, 1);
	msleep(20);
	}

	/* Check Revision ID */
	ret = regmap_read(max98373->regmap,
	MAX98373_R21FF_REV_ID, &reg);
	if (ret < 0) {
	dev_err(&i2c->dev,
	"Failed to read: 0x%02X\n", MAX98373_R21FF_REV_ID);
	return ret;
	}
	dev_info(&i2c->dev, "MAX98373 revisionID: 0x%02X\n", reg);

	/* codec registration */
	ret = devm_snd_soc_register_component(&i2c->dev, &soc_codec_dev_max98373,
	max98373_dai, ARRAY_SIZE(max98373_dai));
	if (ret < 0)
	dev_err(&i2c->dev, "Failed to register codec: %d\n", ret);

	return ret;
	}

	static const struct i2c_device_id max98373_i2c_id[] = {
	{ "max98373", 0},
	{ },
	};

	MODULE_DEVICE_TABLE(i2c, max98373_i2c_id);

	#if defined(CONFIG_OF)
	static const struct of_device_id max98373_of_match[] = {
	{ .compatible = "maxim,max98373", },
	{ }
	};
	MODULE_DEVICE_TABLE(of, max98373_of_match);
	#endif

	#ifdef CONFIG_ACPI
	static const struct acpi_device_id max98373_acpi_match[] = {
	{ "MX98373", 0 },
	{},
	};
	MODULE_DEVICE_TABLE(acpi, max98373_acpi_match);
	#endif

	static struct i2c_driver max98373_i2c_driver = {
	.driver = {
	.name = "max98373",
	.of_match_table = of_match_ptr(max98373_of_match),
	.acpi_match_table = ACPI_PTR(max98373_acpi_match),
	.pm = &max98373_pm,
	},
	.probe = max98373_i2c_probe,
	.id_table = max98373_i2c_id,
	};

	module_i2c_driver(max98373_i2c_driver)

	MODULE_DESCRIPTION("ALSA SoC MAX98373 driver");
	MODULE_AUTHOR("Ryan Lee <ryans.lee@maximintegrated.com>");
	MODULE_LICENSE("GPL");