sound/soc/codecs/ntp8835.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Driver for the NTP8835/NTP8835C Audio Amplifiers
  *
  * Copyright (c) 2024, SaluteDevices. All Rights Reserved.
  *
  * Author: Igor Prusov <ivprusov@salutedevices.com>
  */

 #include <linux/kernel.h>
 #include <linux/clk.h>
 #include <linux/bits.h>
 #include <linux/reset.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/regmap.h>

 #include <sound/initval.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
 #include <sound/soc-component.h>
 #include <sound/tlv.h>

 #include "ntpfw.h"

 #define NTP8835_FORMATS     (SNDRV_PCM_FMTBIT_S16_LE | \
 			     SNDRV_PCM_FMTBIT_S20_3LE | \
 			     SNDRV_PCM_FMTBIT_S24_LE | \
 			     SNDRV_PCM_FMTBIT_S32_LE)

 #define NTP8835_INPUT_FMT			0x0
 #define  NTP8835_INPUT_FMT_MASTER_MODE		BIT(0)
 #define  NTP8835_INPUT_FMT_GSA_MODE		BIT(1)
 #define NTP8835_GSA_FMT				0x1
 #define  NTP8835_GSA_BS_MASK			GENMASK(3, 2)
 #define  NTP8835_GSA_BS(x)			((x) << 2)
 #define  NTP8835_GSA_RIGHT_J			BIT(0)
 #define  NTP8835_GSA_LSB			BIT(1)
 #define NTP8835_MCLK_FREQ_CTRL			0x2
 #define  NTP8835_MCLK_FREQ_MCF			GENMASK(1, 0)
 #define NTP8835_SOFT_MUTE			0x26
 #define  NTP8835_SOFT_MUTE_SM1			BIT(0)
 #define  NTP8835_SOFT_MUTE_SM2			BIT(1)
 #define  NTP8835_SOFT_MUTE_SM3			BIT(2)
 #define NTP8835_PWM_SWITCH			0x27
 #define  NTP8835_PWM_SWITCH_POF1		BIT(0)
 #define  NTP8835_PWM_SWITCH_POF2		BIT(1)
 #define  NTP8835_PWM_SWITCH_POF3		BIT(2)
 #define NTP8835_PWM_MASK_CTRL0			0x28
 #define  NTP8835_PWM_MASK_CTRL0_OUT_LOW		BIT(1)
 #define  NTP8835_PWM_MASK_CTRL0_FPMLD		BIT(2)
 #define NTP8835_MASTER_VOL			0x2e
 #define NTP8835_CHNL_A_VOL			0x2f
 #define NTP8835_CHNL_B_VOL			0x30
 #define NTP8835_CHNL_C_VOL			0x31
 #define REG_MAX					NTP8835_CHNL_C_VOL

 #define NTP8835_FW_NAME				"eq_8835.bin"
 #define NTP8835_FW_MAGIC			0x38383335	/* "8835" */

 struct ntp8835_priv {
 	struct i2c_client *i2c;
 	struct reset_control *reset;
 	unsigned int format;
 	struct clk *mclk;
 	unsigned int mclk_rate;
 };

 static const DECLARE_TLV_DB_RANGE(ntp8835_vol_scale,
 	0, 1, TLV_DB_SCALE_ITEM(-15000, 0, 0),
 	2, 6, TLV_DB_SCALE_ITEM(-15000, 1000, 0),
 	7, 0xff, TLV_DB_SCALE_ITEM(-10000, 50, 0),
 );

 static int ntp8835_mute_info(struct snd_kcontrol *kcontrol,
 			     struct snd_ctl_elem_info *uinfo)
 {
 	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
 	uinfo->access =
 		(SNDRV_CTL_ELEM_ACCESS_TLV_READ | SNDRV_CTL_ELEM_ACCESS_READWRITE);
 	uinfo->count = 1;

 	uinfo->value.integer.min = 0;
 	uinfo->value.integer.max = 1;
 	uinfo->value.integer.step = 1;

 	return 0;
 }

 static int ntp8835_mute_get(struct snd_kcontrol *kcontrol,
 			    struct snd_ctl_elem_value *ucontrol)
 {
 	struct snd_soc_component *component = snd_soc_kcontrol_component(kcontrol);
 	unsigned int val;

 	val = snd_soc_component_read(component, NTP8835_SOFT_MUTE);

 	ucontrol->value.integer.value[0] = val ? 0 : 1;
 	return 0;
 }

 static int ntp8835_mute_put(struct snd_kcontrol *kcontrol,
 			    struct snd_ctl_elem_value *ucontrol)
 {
 	struct snd_soc_component *component = snd_soc_kcontrol_component(kcontrol);
 	unsigned int val;

 	val = ucontrol->value.integer.value[0] ? 0 : 7;

 	snd_soc_component_write(component, NTP8835_SOFT_MUTE, val);

 	return 0;
 }

 static const struct snd_kcontrol_new ntp8835_vol_control[] = {
 	SOC_SINGLE_TLV("Playback Volume", NTP8835_MASTER_VOL, 0,
 		       0xff, 0, ntp8835_vol_scale),
 	{
 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 		.name = "Playback Switch",
 		.info = ntp8835_mute_info,
 		.access = SNDRV_CTL_ELEM_ACCESS_TLV_READ | SNDRV_CTL_ELEM_ACCESS_READWRITE,
 		.get = ntp8835_mute_get,
 		.put = ntp8835_mute_put,
 	},
 };

 static void ntp8835_reset_gpio(struct ntp8835_priv *ntp8835)
 {
 	/*
 	 * Proper initialization sequence for NTP835 amplifier requires driving
 	 * /RESET signal low during power up for at least 0.1us. The sequence is,
 	 * according to NTP8835 datasheet, 6.2 Timing Sequence (recommended):
 	 * Deassert for T2 >= 1ms...
 	 */
 	reset_control_deassert(ntp8835->reset);
 	fsleep(1000);

 	/* ...Assert for T3 >= 0.1us... */
 	reset_control_assert(ntp8835->reset);
 	fsleep(1);

 	/* ...Deassert, and wait for T4 >= 0.5ms before sound on sequence. */
 	reset_control_deassert(ntp8835->reset);
 	fsleep(500);
 }

 static const struct reg_sequence ntp8835_sound_on[] = {
 	{ NTP8835_PWM_MASK_CTRL0,	NTP8835_PWM_MASK_CTRL0_FPMLD },
 	{ NTP8835_PWM_SWITCH,		0x00 },
 	{ NTP8835_SOFT_MUTE,		0x00 },
 };

 static const struct reg_sequence ntp8835_sound_off[] = {
 	{ NTP8835_SOFT_MUTE,		NTP8835_SOFT_MUTE_SM1 |
 					NTP8835_SOFT_MUTE_SM2 |
 					NTP8835_SOFT_MUTE_SM3 },

 	{ NTP8835_PWM_SWITCH,		NTP8835_PWM_SWITCH_POF1 |
 					NTP8835_PWM_SWITCH_POF2 |
 					NTP8835_PWM_SWITCH_POF3 },

 	{ NTP8835_PWM_MASK_CTRL0,	NTP8835_PWM_MASK_CTRL0_OUT_LOW |
 					NTP8835_PWM_MASK_CTRL0_FPMLD },
 };

 static int ntp8835_load_firmware(struct ntp8835_priv *ntp8835)
 {
 	int ret;

 	ret = ntpfw_load(ntp8835->i2c, NTP8835_FW_NAME, NTP8835_FW_MAGIC);
 	if (ret == -ENOENT) {
 		dev_warn_once(&ntp8835->i2c->dev,
 			      "Could not find firmware %s\n", NTP8835_FW_NAME);
 		return 0;
 	}

 	return ret;
 }

 static int ntp8835_snd_suspend(struct snd_soc_component *component)
 {
 	struct ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);

 	regcache_cache_only(component->regmap, true);

 	regmap_multi_reg_write_bypassed(component->regmap,
 					ntp8835_sound_off,
 					ARRAY_SIZE(ntp8835_sound_off));

 	/*
 	 * According to NTP8835 datasheet, 6.2 Timing Sequence (recommended):
 	 * wait after sound off for T6 >= 0.5ms
 	 */
 	fsleep(500);
 	reset_control_assert(ntp8835->reset);

 	regcache_mark_dirty(component->regmap);
 	clk_disable_unprepare(ntp8835->mclk);

 	return 0;
 }

 static int ntp8835_snd_resume(struct snd_soc_component *component)
 {
 	struct ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);
 	int ret;

 	ntp8835_reset_gpio(ntp8835);
 	ret = clk_prepare_enable(ntp8835->mclk);
 	if (ret)
 		return ret;

 	regmap_multi_reg_write_bypassed(component->regmap,
 					ntp8835_sound_on,
 					ARRAY_SIZE(ntp8835_sound_on));

 	ret = ntp8835_load_firmware(ntp8835);
 	if (ret) {
 		dev_err(&ntp8835->i2c->dev, "Failed to load firmware\n");
 		return ret;
 	}

 	regcache_cache_only(component->regmap, false);
 	snd_soc_component_cache_sync(component);

 	return 0;
 }

 static int ntp8835_probe(struct snd_soc_component *component)
 {
 	int ret;
 	struct ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);
 	struct device *dev = component->dev;

 	ret = snd_soc_add_component_controls(component, ntp8835_vol_control,
 					     ARRAY_SIZE(ntp8835_vol_control));
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to add controls\n");

 	ret = ntp8835_load_firmware(ntp8835);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to load firmware\n");

 	return 0;
 }

 static const struct snd_soc_dapm_widget ntp8835_dapm_widgets[] = {
 	SND_SOC_DAPM_DAC("AIFIN", "Playback", SND_SOC_NOPM, 0, 0),

 	SND_SOC_DAPM_OUTPUT("OUT1"),
 	SND_SOC_DAPM_OUTPUT("OUT2"),
 	SND_SOC_DAPM_OUTPUT("OUT3"),
 };

 static const struct snd_soc_dapm_route ntp8835_dapm_routes[] = {
 	{ "OUT1", NULL, "AIFIN" },
 	{ "OUT2", NULL, "AIFIN" },
 	{ "OUT3", NULL, "AIFIN" },
 };

 static int ntp8835_set_component_sysclk(struct snd_soc_component *component,
 				       int clk_id, int source,
 				       unsigned int freq, int dir)
 {
 	struct ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);

 	switch (freq) {
 	case 12288000:
 	case 24576000:
 	case 18432000:
 		ntp8835->mclk_rate = freq;
 		break;
 	default:
 		ntp8835->mclk_rate = 0;
 		dev_err(component->dev, "Unsupported MCLK value: %u", freq);
 		return -EINVAL;
 	}

 	return 0;
 }

 static const struct snd_soc_component_driver soc_component_ntp8835 = {
 	.probe = ntp8835_probe,
 	.suspend = ntp8835_snd_suspend,
 	.resume = ntp8835_snd_resume,
 	.dapm_widgets = ntp8835_dapm_widgets,
 	.num_dapm_widgets = ARRAY_SIZE(ntp8835_dapm_widgets),
 	.dapm_routes = ntp8835_dapm_routes,
 	.num_dapm_routes = ARRAY_SIZE(ntp8835_dapm_routes),
 	.set_sysclk = ntp8835_set_component_sysclk,
 };

 static int ntp8835_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 ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);
 	unsigned int input_fmt = 0;
 	unsigned int gsa_fmt = 0;
 	unsigned int gsa_fmt_mask;
 	unsigned int mcf;
 	int ret;

 	switch (ntp8835->mclk_rate) {
 	case 12288000:
 		mcf = 0;
 		break;
 	case 24576000:
 		mcf = 1;
 		break;
 	case 18432000:
 		mcf = 2;
 		break;
 	default:
 		return -EINVAL;
 	}

 	ret = snd_soc_component_update_bits(component, NTP8835_MCLK_FREQ_CTRL,
 					    NTP8835_MCLK_FREQ_MCF, mcf);
 	if (ret)
 		return ret;

 	switch (ntp8835->format) {
 	case SND_SOC_DAIFMT_I2S:
 		break;
 	case SND_SOC_DAIFMT_RIGHT_J:
 		input_fmt |= NTP8835_INPUT_FMT_GSA_MODE;
 		gsa_fmt |= NTP8835_GSA_RIGHT_J;
 		break;
 	case SND_SOC_DAIFMT_LEFT_J:
 		input_fmt |= NTP8835_INPUT_FMT_GSA_MODE;
 		break;
 	}

 	ret = snd_soc_component_update_bits(component, NTP8835_INPUT_FMT,
 					    NTP8835_INPUT_FMT_MASTER_MODE |
 					    NTP8835_INPUT_FMT_GSA_MODE,
 					    input_fmt);

 	if (!(input_fmt & NTP8835_INPUT_FMT_GSA_MODE) || ret < 0)
 		return ret;

 	switch (params_width(params)) {
 	case 24:
 		gsa_fmt |= NTP8835_GSA_BS(0);
 		break;
 	case 20:
 		gsa_fmt |= NTP8835_GSA_BS(1);
 		break;
 	case 18:
 		gsa_fmt |= NTP8835_GSA_BS(2);
 		break;
 	case 16:
 		gsa_fmt |= NTP8835_GSA_BS(3);
 		break;
 	default:
 		return -EINVAL;
 	}

 	gsa_fmt_mask = NTP8835_GSA_BS_MASK |
 		       NTP8835_GSA_RIGHT_J |
 		       NTP8835_GSA_LSB;
 	return snd_soc_component_update_bits(component, NTP8835_GSA_FMT,
 					     gsa_fmt_mask, gsa_fmt);
 }

 static int ntp8835_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 {
 	struct snd_soc_component *component = dai->component;
 	struct ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);

 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_I2S:
 	case SND_SOC_DAIFMT_RIGHT_J:
 	case SND_SOC_DAIFMT_LEFT_J:
 		ntp8835->format = fmt & SND_SOC_DAIFMT_FORMAT_MASK;
 		break;
 	default:
 		return -EINVAL;
 	}
 	return 0;
 };

 static const struct snd_soc_dai_ops ntp8835_dai_ops = {
 	.hw_params = ntp8835_hw_params,
 	.set_fmt = ntp8835_set_fmt,
 };

 static struct snd_soc_dai_driver ntp8835_dai = {
 	.name = "ntp8835-amplifier",
 	.playback = {
 		.stream_name = "Playback",
 		.channels_min = 1,
 		.channels_max = 3,
 		.rates = SNDRV_PCM_RATE_8000_192000,
 		.formats = NTP8835_FORMATS,
 	},
 	.ops = &ntp8835_dai_ops,
 };

 static const struct regmap_config ntp8835_regmap = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.max_register = REG_MAX,
 	.cache_type = REGCACHE_MAPLE,
 };

 static int ntp8835_i2c_probe(struct i2c_client *i2c)
 {
 	struct ntp8835_priv *ntp8835;
 	struct regmap *regmap;
 	int ret;

 	ntp8835 = devm_kzalloc(&i2c->dev, sizeof(*ntp8835), GFP_KERNEL);
 	if (!ntp8835)
 		return -ENOMEM;

 	ntp8835->i2c = i2c;

 	ntp8835->reset = devm_reset_control_get_shared(&i2c->dev, NULL);
 	if (IS_ERR(ntp8835->reset))
 		return dev_err_probe(&i2c->dev, PTR_ERR(ntp8835->reset),
 				     "Failed to get reset\n");

 	ret = reset_control_deassert(ntp8835->reset);
 	if (ret)
 		return dev_err_probe(&i2c->dev, ret,
 				     "Failed to deassert reset\n");

 	dev_set_drvdata(&i2c->dev, ntp8835);

 	ntp8835_reset_gpio(ntp8835);

 	regmap = devm_regmap_init_i2c(i2c, &ntp8835_regmap);
 	if (IS_ERR(regmap))
 		return dev_err_probe(&i2c->dev, PTR_ERR(regmap),
 				     "Failed to allocate regmap\n");

 	ret = devm_snd_soc_register_component(&i2c->dev, &soc_component_ntp8835,
 					      &ntp8835_dai, 1);
 	if (ret)
 		return dev_err_probe(&i2c->dev, ret,
 				     "Failed to register component\n");

 	ntp8835->mclk = devm_clk_get_enabled(&i2c->dev, "mclk");
 	if (IS_ERR(ntp8835->mclk))
 		return dev_err_probe(&i2c->dev, PTR_ERR(ntp8835->mclk), "failed to get mclk\n");

 	return 0;
 }

 static const struct i2c_device_id ntp8835_i2c_id[] = {
 	{ "ntp8835" },
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, ntp8835_i2c_id);

 static const struct of_device_id ntp8835_of_match[] = {
 	{.compatible = "neofidelity,ntp8835",},
 	{}
 };
 MODULE_DEVICE_TABLE(of, ntp8835_of_match);

 static struct i2c_driver ntp8835_i2c_driver = {
 	.probe = ntp8835_i2c_probe,
 	.id_table = ntp8835_i2c_id,
 	.driver = {
 		.name = "ntp8835",
 		.of_match_table = ntp8835_of_match,
 	},
 };
 module_i2c_driver(ntp8835_i2c_driver);

 MODULE_AUTHOR("Igor Prusov <ivprusov@salutedevices.com>");
 MODULE_DESCRIPTION("NTP8835 Audio Amplifier Driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Driver for the NTP8835/NTP8835C Audio Amplifiers
	*
	* Copyright (c) 2024, SaluteDevices. All Rights Reserved.
	*
	* Author: Igor Prusov <ivprusov@salutedevices.com>
	*/

	#include <linux/kernel.h>
	#include <linux/clk.h>
	#include <linux/bits.h>
	#include <linux/reset.h>
	#include <linux/init.h>
	#include <linux/i2c.h>
	#include <linux/regmap.h>

	#include <sound/initval.h>
	#include <sound/core.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include <sound/soc.h>
	#include <sound/soc-component.h>
	#include <sound/tlv.h>

	#include "ntpfw.h"

	#define NTP8835_FORMATS (SNDRV_PCM_FMTBIT_S16_LE \| \
	SNDRV_PCM_FMTBIT_S20_3LE \| \
	SNDRV_PCM_FMTBIT_S24_LE \| \
	SNDRV_PCM_FMTBIT_S32_LE)

	#define NTP8835_INPUT_FMT 0x0
	#define NTP8835_INPUT_FMT_MASTER_MODE BIT(0)
	#define NTP8835_INPUT_FMT_GSA_MODE BIT(1)
	#define NTP8835_GSA_FMT 0x1
	#define NTP8835_GSA_BS_MASK GENMASK(3, 2)
	#define NTP8835_GSA_BS(x) ((x) << 2)
	#define NTP8835_GSA_RIGHT_J BIT(0)
	#define NTP8835_GSA_LSB BIT(1)
	#define NTP8835_MCLK_FREQ_CTRL 0x2
	#define NTP8835_MCLK_FREQ_MCF GENMASK(1, 0)
	#define NTP8835_SOFT_MUTE 0x26
	#define NTP8835_SOFT_MUTE_SM1 BIT(0)
	#define NTP8835_SOFT_MUTE_SM2 BIT(1)
	#define NTP8835_SOFT_MUTE_SM3 BIT(2)
	#define NTP8835_PWM_SWITCH 0x27
	#define NTP8835_PWM_SWITCH_POF1 BIT(0)
	#define NTP8835_PWM_SWITCH_POF2 BIT(1)
	#define NTP8835_PWM_SWITCH_POF3 BIT(2)
	#define NTP8835_PWM_MASK_CTRL0 0x28
	#define NTP8835_PWM_MASK_CTRL0_OUT_LOW BIT(1)
	#define NTP8835_PWM_MASK_CTRL0_FPMLD BIT(2)
	#define NTP8835_MASTER_VOL 0x2e
	#define NTP8835_CHNL_A_VOL 0x2f
	#define NTP8835_CHNL_B_VOL 0x30
	#define NTP8835_CHNL_C_VOL 0x31
	#define REG_MAX NTP8835_CHNL_C_VOL

	#define NTP8835_FW_NAME "eq_8835.bin"
	#define NTP8835_FW_MAGIC 0x38383335 /* "8835" */

	struct ntp8835_priv {
	struct i2c_client *i2c;
	struct reset_control *reset;
	unsigned int format;
	struct clk *mclk;
	unsigned int mclk_rate;
	};

	static const DECLARE_TLV_DB_RANGE(ntp8835_vol_scale,
	0, 1, TLV_DB_SCALE_ITEM(-15000, 0, 0),
	2, 6, TLV_DB_SCALE_ITEM(-15000, 1000, 0),
	7, 0xff, TLV_DB_SCALE_ITEM(-10000, 50, 0),
	);

	static int ntp8835_mute_info(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_info *uinfo)
	{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
	uinfo->access =
	(SNDRV_CTL_ELEM_ACCESS_TLV_READ \| SNDRV_CTL_ELEM_ACCESS_READWRITE);
	uinfo->count = 1;

	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 1;
	uinfo->value.integer.step = 1;

	return 0;
	}

	static int ntp8835_mute_get(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_value *ucontrol)
	{
	struct snd_soc_component *component = snd_soc_kcontrol_component(kcontrol);
	unsigned int val;

	val = snd_soc_component_read(component, NTP8835_SOFT_MUTE);

	ucontrol->value.integer.value[0] = val ? 0 : 1;
	return 0;
	}

	static int ntp8835_mute_put(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_value *ucontrol)
	{
	struct snd_soc_component *component = snd_soc_kcontrol_component(kcontrol);
	unsigned int val;

	val = ucontrol->value.integer.value[0] ? 0 : 7;

	snd_soc_component_write(component, NTP8835_SOFT_MUTE, val);

	return 0;
	}

	static const struct snd_kcontrol_new ntp8835_vol_control[] = {
	SOC_SINGLE_TLV("Playback Volume", NTP8835_MASTER_VOL, 0,
	0xff, 0, ntp8835_vol_scale),
	{
	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
	.name = "Playback Switch",
	.info = ntp8835_mute_info,
	.access = SNDRV_CTL_ELEM_ACCESS_TLV_READ \| SNDRV_CTL_ELEM_ACCESS_READWRITE,
	.get = ntp8835_mute_get,
	.put = ntp8835_mute_put,
	},
	};

	static void ntp8835_reset_gpio(struct ntp8835_priv *ntp8835)
	{
	/*
	* Proper initialization sequence for NTP835 amplifier requires driving
	* /RESET signal low during power up for at least 0.1us. The sequence is,
	* according to NTP8835 datasheet, 6.2 Timing Sequence (recommended):
	* Deassert for T2 >= 1ms...
	*/
	reset_control_deassert(ntp8835->reset);
	fsleep(1000);

	/* ...Assert for T3 >= 0.1us... */
	reset_control_assert(ntp8835->reset);
	fsleep(1);

	/* ...Deassert, and wait for T4 >= 0.5ms before sound on sequence. */
	reset_control_deassert(ntp8835->reset);
	fsleep(500);
	}

	static const struct reg_sequence ntp8835_sound_on[] = {
	{ NTP8835_PWM_MASK_CTRL0, NTP8835_PWM_MASK_CTRL0_FPMLD },
	{ NTP8835_PWM_SWITCH, 0x00 },
	{ NTP8835_SOFT_MUTE, 0x00 },
	};

	static const struct reg_sequence ntp8835_sound_off[] = {
	{ NTP8835_SOFT_MUTE, NTP8835_SOFT_MUTE_SM1 \|
	NTP8835_SOFT_MUTE_SM2 \|
	NTP8835_SOFT_MUTE_SM3 },

	{ NTP8835_PWM_SWITCH, NTP8835_PWM_SWITCH_POF1 \|
	NTP8835_PWM_SWITCH_POF2 \|
	NTP8835_PWM_SWITCH_POF3 },

	{ NTP8835_PWM_MASK_CTRL0, NTP8835_PWM_MASK_CTRL0_OUT_LOW \|
	NTP8835_PWM_MASK_CTRL0_FPMLD },
	};

	static int ntp8835_load_firmware(struct ntp8835_priv *ntp8835)
	{
	int ret;

	ret = ntpfw_load(ntp8835->i2c, NTP8835_FW_NAME, NTP8835_FW_MAGIC);
	if (ret == -ENOENT) {
	dev_warn_once(&ntp8835->i2c->dev,
	"Could not find firmware %s\n", NTP8835_FW_NAME);
	return 0;
	}

	return ret;
	}

	static int ntp8835_snd_suspend(struct snd_soc_component *component)
	{
	struct ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);

	regcache_cache_only(component->regmap, true);

	regmap_multi_reg_write_bypassed(component->regmap,
	ntp8835_sound_off,
	ARRAY_SIZE(ntp8835_sound_off));

	/*
	* According to NTP8835 datasheet, 6.2 Timing Sequence (recommended):
	* wait after sound off for T6 >= 0.5ms
	*/
	fsleep(500);
	reset_control_assert(ntp8835->reset);

	regcache_mark_dirty(component->regmap);
	clk_disable_unprepare(ntp8835->mclk);

	return 0;
	}

	static int ntp8835_snd_resume(struct snd_soc_component *component)
	{
	struct ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);
	int ret;

	ntp8835_reset_gpio(ntp8835);
	ret = clk_prepare_enable(ntp8835->mclk);
	if (ret)
	return ret;

	regmap_multi_reg_write_bypassed(component->regmap,
	ntp8835_sound_on,
	ARRAY_SIZE(ntp8835_sound_on));

	ret = ntp8835_load_firmware(ntp8835);
	if (ret) {
	dev_err(&ntp8835->i2c->dev, "Failed to load firmware\n");
	return ret;
	}

	regcache_cache_only(component->regmap, false);
	snd_soc_component_cache_sync(component);

	return 0;
	}

	static int ntp8835_probe(struct snd_soc_component *component)
	{
	int ret;
	struct ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);
	struct device *dev = component->dev;

	ret = snd_soc_add_component_controls(component, ntp8835_vol_control,
	ARRAY_SIZE(ntp8835_vol_control));
	if (ret)
	return dev_err_probe(dev, ret, "Failed to add controls\n");

	ret = ntp8835_load_firmware(ntp8835);
	if (ret)
	return dev_err_probe(dev, ret, "Failed to load firmware\n");

	return 0;
	}

	static const struct snd_soc_dapm_widget ntp8835_dapm_widgets[] = {
	SND_SOC_DAPM_DAC("AIFIN", "Playback", SND_SOC_NOPM, 0, 0),

	SND_SOC_DAPM_OUTPUT("OUT1"),
	SND_SOC_DAPM_OUTPUT("OUT2"),
	SND_SOC_DAPM_OUTPUT("OUT3"),
	};

	static const struct snd_soc_dapm_route ntp8835_dapm_routes[] = {
	{ "OUT1", NULL, "AIFIN" },
	{ "OUT2", NULL, "AIFIN" },
	{ "OUT3", NULL, "AIFIN" },
	};

	static int ntp8835_set_component_sysclk(struct snd_soc_component *component,
	int clk_id, int source,
	unsigned int freq, int dir)
	{
	struct ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);

	switch (freq) {
	case 12288000:
	case 24576000:
	case 18432000:
	ntp8835->mclk_rate = freq;
	break;
	default:
	ntp8835->mclk_rate = 0;
	dev_err(component->dev, "Unsupported MCLK value: %u", freq);
	return -EINVAL;
	}

	return 0;
	}

	static const struct snd_soc_component_driver soc_component_ntp8835 = {
	.probe = ntp8835_probe,
	.suspend = ntp8835_snd_suspend,
	.resume = ntp8835_snd_resume,
	.dapm_widgets = ntp8835_dapm_widgets,
	.num_dapm_widgets = ARRAY_SIZE(ntp8835_dapm_widgets),
	.dapm_routes = ntp8835_dapm_routes,
	.num_dapm_routes = ARRAY_SIZE(ntp8835_dapm_routes),
	.set_sysclk = ntp8835_set_component_sysclk,
	};

	static int ntp8835_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 ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);
	unsigned int input_fmt = 0;
	unsigned int gsa_fmt = 0;
	unsigned int gsa_fmt_mask;
	unsigned int mcf;
	int ret;

	switch (ntp8835->mclk_rate) {
	case 12288000:
	mcf = 0;
	break;
	case 24576000:
	mcf = 1;
	break;
	case 18432000:
	mcf = 2;
	break;
	default:
	return -EINVAL;
	}

	ret = snd_soc_component_update_bits(component, NTP8835_MCLK_FREQ_CTRL,
	NTP8835_MCLK_FREQ_MCF, mcf);
	if (ret)
	return ret;

	switch (ntp8835->format) {
	case SND_SOC_DAIFMT_I2S:
	break;
	case SND_SOC_DAIFMT_RIGHT_J:
	input_fmt \|= NTP8835_INPUT_FMT_GSA_MODE;
	gsa_fmt \|= NTP8835_GSA_RIGHT_J;
	break;
	case SND_SOC_DAIFMT_LEFT_J:
	input_fmt \|= NTP8835_INPUT_FMT_GSA_MODE;
	break;
	}

	ret = snd_soc_component_update_bits(component, NTP8835_INPUT_FMT,
	NTP8835_INPUT_FMT_MASTER_MODE \|
	NTP8835_INPUT_FMT_GSA_MODE,
	input_fmt);

	if (!(input_fmt & NTP8835_INPUT_FMT_GSA_MODE) \|\| ret < 0)
	return ret;

	switch (params_width(params)) {
	case 24:
	gsa_fmt \|= NTP8835_GSA_BS(0);
	break;
	case 20:
	gsa_fmt \|= NTP8835_GSA_BS(1);
	break;
	case 18:
	gsa_fmt \|= NTP8835_GSA_BS(2);
	break;
	case 16:
	gsa_fmt \|= NTP8835_GSA_BS(3);
	break;
	default:
	return -EINVAL;
	}

	gsa_fmt_mask = NTP8835_GSA_BS_MASK \|
	NTP8835_GSA_RIGHT_J \|
	NTP8835_GSA_LSB;
	return snd_soc_component_update_bits(component, NTP8835_GSA_FMT,
	gsa_fmt_mask, gsa_fmt);
	}

	static int ntp8835_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
	{
	struct snd_soc_component *component = dai->component;
	struct ntp8835_priv *ntp8835 = snd_soc_component_get_drvdata(component);

	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
	case SND_SOC_DAIFMT_RIGHT_J:
	case SND_SOC_DAIFMT_LEFT_J:
	ntp8835->format = fmt & SND_SOC_DAIFMT_FORMAT_MASK;
	break;
	default:
	return -EINVAL;
	}
	return 0;
	};

	static const struct snd_soc_dai_ops ntp8835_dai_ops = {
	.hw_params = ntp8835_hw_params,
	.set_fmt = ntp8835_set_fmt,
	};

	static struct snd_soc_dai_driver ntp8835_dai = {
	.name = "ntp8835-amplifier",
	.playback = {
	.stream_name = "Playback",
	.channels_min = 1,
	.channels_max = 3,
	.rates = SNDRV_PCM_RATE_8000_192000,
	.formats = NTP8835_FORMATS,
	},
	.ops = &ntp8835_dai_ops,
	};

	static const struct regmap_config ntp8835_regmap = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = REG_MAX,
	.cache_type = REGCACHE_MAPLE,
	};

	static int ntp8835_i2c_probe(struct i2c_client *i2c)
	{
	struct ntp8835_priv *ntp8835;
	struct regmap *regmap;
	int ret;

	ntp8835 = devm_kzalloc(&i2c->dev, sizeof(*ntp8835), GFP_KERNEL);
	if (!ntp8835)
	return -ENOMEM;

	ntp8835->i2c = i2c;

	ntp8835->reset = devm_reset_control_get_shared(&i2c->dev, NULL);
	if (IS_ERR(ntp8835->reset))
	return dev_err_probe(&i2c->dev, PTR_ERR(ntp8835->reset),
	"Failed to get reset\n");

	ret = reset_control_deassert(ntp8835->reset);
	if (ret)
	return dev_err_probe(&i2c->dev, ret,
	"Failed to deassert reset\n");

	dev_set_drvdata(&i2c->dev, ntp8835);

	ntp8835_reset_gpio(ntp8835);

	regmap = devm_regmap_init_i2c(i2c, &ntp8835_regmap);
	if (IS_ERR(regmap))
	return dev_err_probe(&i2c->dev, PTR_ERR(regmap),
	"Failed to allocate regmap\n");

	ret = devm_snd_soc_register_component(&i2c->dev, &soc_component_ntp8835,
	&ntp8835_dai, 1);
	if (ret)
	return dev_err_probe(&i2c->dev, ret,
	"Failed to register component\n");

	ntp8835->mclk = devm_clk_get_enabled(&i2c->dev, "mclk");
	if (IS_ERR(ntp8835->mclk))
	return dev_err_probe(&i2c->dev, PTR_ERR(ntp8835->mclk), "failed to get mclk\n");

	return 0;
	}

	static const struct i2c_device_id ntp8835_i2c_id[] = {
	{ "ntp8835" },
	{}
	};
	MODULE_DEVICE_TABLE(i2c, ntp8835_i2c_id);

	static const struct of_device_id ntp8835_of_match[] = {
	{.compatible = "neofidelity,ntp8835",},
	{}
	};
	MODULE_DEVICE_TABLE(of, ntp8835_of_match);

	static struct i2c_driver ntp8835_i2c_driver = {
	.probe = ntp8835_i2c_probe,
	.id_table = ntp8835_i2c_id,
	.driver = {
	.name = "ntp8835",
	.of_match_table = ntp8835_of_match,
	},
	};
	module_i2c_driver(ntp8835_i2c_driver);

	MODULE_AUTHOR("Igor Prusov <ivprusov@salutedevices.com>");
	MODULE_DESCRIPTION("NTP8835 Audio Amplifier Driver");
	MODULE_LICENSE("GPL");