ASoC: ak5558: Add support for AK5558 ADC driver

AK5558 is a 32-bit, 768 kHZ sampling, differential input ADC
for digital audio systems.

Datasheet is available at:

https://www.akm.com/akm/en/file/datasheet/AK5558VN.pdf

Initial patch includes support for normal and TDM modes.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Junichi Wakasugi <wakasugi.jb@om.asahi-kasei.co.jp>
[initial coding for 3.18 kernel]
Signed-off-by: Mihai Serban <mihai.serban@nxp.com>
[cleanups and porting to 4.9 kernel]
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
[tdm support]
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
[pm support, cleanups and porting to latest kernel]
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/ak5558.c b/sound/soc/codecs/ak5558.c
new file mode 100644
index 0000000..225173f
--- /dev/null
+++ b/sound/soc/codecs/ak5558.c
@@ -0,0 +1,417 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Audio driver for AK5558 ADC
+ *
+ * Copyright (C) 2015 Asahi Kasei Microdevices Corporation
+ * Copyright 2018 NXP
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/soc-dapm.h>
+#include <sound/tlv.h>
+
+#include "ak5558.h"
+
+/* AK5558 Codec Private Data */
+struct ak5558_priv {
+	struct snd_soc_codec codec;
+	struct regmap *regmap;
+	struct i2c_client *i2c;
+	struct gpio_desc *reset_gpiod; /* Reset & Power down GPIO */
+	int slots;
+	int slot_width;
+};
+
+/* ak5558 register cache & default register settings */
+static const struct reg_default ak5558_reg[] = {
+	{ 0x0, 0xFF },	/*	0x00	AK5558_00_POWER_MANAGEMENT1	*/
+	{ 0x1, 0x01 },	/*	0x01	AK5558_01_POWER_MANAGEMENT2	*/
+	{ 0x2, 0x01 },	/*	0x02	AK5558_02_CONTROL1		*/
+	{ 0x3, 0x00 },	/*	0x03	AK5558_03_CONTROL2		*/
+	{ 0x4, 0x00 },	/*	0x04	AK5558_04_CONTROL3		*/
+	{ 0x5, 0x00 }	/*	0x05	AK5558_05_DSD			*/
+};
+
+static const char * const mono_texts[] = {
+	"8 Slot", "2 Slot", "4 Slot", "1 Slot",
+};
+
+static const struct soc_enum ak5558_mono_enum[] = {
+	SOC_ENUM_SINGLE(AK5558_01_POWER_MANAGEMENT2, 1,
+			ARRAY_SIZE(mono_texts), mono_texts),
+};
+
+static const char * const digfil_texts[] = {
+	"Sharp Roll-Off", "Show Roll-Off",
+	"Short Delay Sharp Roll-Off", "Short Delay Show Roll-Off",
+};
+
+static const struct soc_enum ak5558_adcset_enum[] = {
+	SOC_ENUM_SINGLE(AK5558_04_CONTROL3, 0,
+			ARRAY_SIZE(digfil_texts), digfil_texts),
+};
+
+static const struct snd_kcontrol_new ak5558_snd_controls[] = {
+	SOC_ENUM("AK5558 Monaural Mode", ak5558_mono_enum[0]),
+	SOC_ENUM("AK5558 Digital Filter", ak5558_adcset_enum[0]),
+};
+
+static const struct snd_soc_dapm_widget ak5558_dapm_widgets[] = {
+	/* Analog Input */
+	SND_SOC_DAPM_INPUT("AIN1"),
+	SND_SOC_DAPM_INPUT("AIN2"),
+	SND_SOC_DAPM_INPUT("AIN3"),
+	SND_SOC_DAPM_INPUT("AIN4"),
+	SND_SOC_DAPM_INPUT("AIN5"),
+	SND_SOC_DAPM_INPUT("AIN6"),
+	SND_SOC_DAPM_INPUT("AIN7"),
+	SND_SOC_DAPM_INPUT("AIN8"),
+
+	SND_SOC_DAPM_ADC("ADC Ch1", NULL, AK5558_00_POWER_MANAGEMENT1, 0, 0),
+	SND_SOC_DAPM_ADC("ADC Ch2", NULL, AK5558_00_POWER_MANAGEMENT1, 1, 0),
+	SND_SOC_DAPM_ADC("ADC Ch3", NULL, AK5558_00_POWER_MANAGEMENT1, 2, 0),
+	SND_SOC_DAPM_ADC("ADC Ch4", NULL, AK5558_00_POWER_MANAGEMENT1, 3, 0),
+	SND_SOC_DAPM_ADC("ADC Ch5", NULL, AK5558_00_POWER_MANAGEMENT1, 4, 0),
+	SND_SOC_DAPM_ADC("ADC Ch6", NULL, AK5558_00_POWER_MANAGEMENT1, 5, 0),
+	SND_SOC_DAPM_ADC("ADC Ch7", NULL, AK5558_00_POWER_MANAGEMENT1, 6, 0),
+	SND_SOC_DAPM_ADC("ADC Ch8", NULL, AK5558_00_POWER_MANAGEMENT1, 7, 0),
+
+	SND_SOC_DAPM_AIF_OUT("SDTO", "Capture", 0, SND_SOC_NOPM, 0, 0),
+};
+
+static const struct snd_soc_dapm_route ak5558_intercon[] = {
+	{"ADC Ch1", NULL, "AIN1"},
+	{"SDTO", NULL, "ADC Ch1"},
+
+	{"ADC Ch2", NULL, "AIN2"},
+	{"SDTO", NULL, "ADC Ch2"},
+
+	{"ADC Ch3", NULL, "AIN3"},
+	{"SDTO", NULL, "ADC Ch3"},
+
+	{"ADC Ch4", NULL, "AIN4"},
+	{"SDTO", NULL, "ADC Ch4"},
+
+	{"ADC Ch5", NULL, "AIN5"},
+	{"SDTO", NULL, "ADC Ch5"},
+
+	{"ADC Ch6", NULL, "AIN6"},
+	{"SDTO", NULL, "ADC Ch6"},
+
+	{"ADC Ch7", NULL, "AIN7"},
+	{"SDTO", NULL, "ADC Ch7"},
+
+	{"ADC Ch8", NULL, "AIN8"},
+	{"SDTO", NULL, "ADC Ch8"},
+};
+
+static int ak5558_set_mcki(struct snd_soc_codec *codec)
+{
+	return snd_soc_update_bits(codec, AK5558_02_CONTROL1, AK5558_CKS,
+				   AK5558_CKS_AUTO);
+}
+
+static int ak5558_hw_params(struct snd_pcm_substream *substream,
+			    struct snd_pcm_hw_params *params,
+			    struct snd_soc_dai *dai)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	struct ak5558_priv *ak5558 = snd_soc_codec_get_drvdata(codec);
+	u8 bits;
+	int pcm_width = max(params_physical_width(params), ak5558->slot_width);
+
+	/* set master/slave audio interface */
+	bits = snd_soc_read(codec, AK5558_02_CONTROL1);
+	bits &= ~AK5558_BITS;
+
+	switch (pcm_width) {
+	case 16:
+		bits |= AK5558_DIF_24BIT_MODE;
+		break;
+	case 32:
+		bits |= AK5558_DIF_32BIT_MODE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	snd_soc_update_bits(codec, AK5558_02_CONTROL1, AK5558_BITS, bits);
+
+	return 0;
+}
+
+static int ak5558_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	u8 format;
+
+	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBS_CFS:
+		break;
+	case SND_SOC_DAIFMT_CBM_CFM:
+		break;
+	case SND_SOC_DAIFMT_CBS_CFM:
+	case SND_SOC_DAIFMT_CBM_CFS:
+	default:
+		dev_err(dai->dev, "Clock mode unsupported");
+		return -EINVAL;
+	}
+
+	/* set master/slave audio interface */
+	format = snd_soc_read(codec, AK5558_02_CONTROL1);
+	format &= ~AK5558_DIF;
+
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		format |= AK5558_DIF_I2S_MODE;
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		format |= AK5558_DIF_MSB_MODE;
+		break;
+	case SND_SOC_DAIFMT_DSP_B:
+		format |= AK5558_DIF_MSB_MODE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	snd_soc_update_bits(codec, AK5558_02_CONTROL1, AK5558_DIF, format);
+
+	return 0;
+}
+
+static int ak5558_set_tdm_slot(struct snd_soc_dai *dai, unsigned int tx_mask,
+			       unsigned int rx_mask, int slots,
+			       int slot_width)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	struct ak5558_priv *ak5558 = snd_soc_codec_get_drvdata(codec);
+	int tdm_mode;
+
+	ak5558->slots = slots;
+	ak5558->slot_width = slot_width;
+
+	switch (slots * slot_width) {
+	case 128:
+		tdm_mode = AK5558_MODE_TDM128;
+		break;
+	case 256:
+		tdm_mode = AK5558_MODE_TDM256;
+		break;
+	case 512:
+		tdm_mode = AK5558_MODE_TDM512;
+		break;
+	default:
+		tdm_mode = AK5558_MODE_NORMAL;
+		break;
+	}
+
+	snd_soc_update_bits(codec, AK5558_03_CONTROL2, AK5558_MODE_BITS,
+			    tdm_mode);
+	return 0;
+}
+
+#define AK5558_FORMATS	(SNDRV_PCM_FMTBIT_S16_LE |\
+			 SNDRV_PCM_FMTBIT_S24_LE |\
+			 SNDRV_PCM_FMTBIT_S32_LE)
+
+static const unsigned int ak5558_rates[] = {
+	8000, 11025,  16000, 22050,
+	32000, 44100, 48000, 88200,
+	96000, 176400, 192000, 352800,
+	384000, 705600, 768000, 1411200,
+	2822400,
+};
+
+static const struct snd_pcm_hw_constraint_list ak5558_rate_constraints = {
+	.count = ARRAY_SIZE(ak5558_rates),
+	.list = ak5558_rates,
+};
+
+static int ak5558_startup(struct snd_pcm_substream *substream,
+			  struct snd_soc_dai *dai)
+{
+	return snd_pcm_hw_constraint_list(substream->runtime, 0,
+					  SNDRV_PCM_HW_PARAM_RATE,
+					  &ak5558_rate_constraints);
+}
+
+static struct snd_soc_dai_ops ak5558_dai_ops = {
+	.startup        = ak5558_startup,
+	.hw_params	= ak5558_hw_params,
+
+	.set_fmt	= ak5558_set_dai_fmt,
+	.set_tdm_slot   = ak5558_set_tdm_slot,
+};
+
+static struct snd_soc_dai_driver ak5558_dai = {
+	.name = "ak5558-aif",
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 1,
+		.channels_max = 8,
+		.rates = SNDRV_PCM_RATE_KNOT,
+		.formats = AK5558_FORMATS,
+	},
+	.ops = &ak5558_dai_ops,
+};
+
+static void ak5558_power_off(struct ak5558_priv *ak5558)
+{
+	if (!ak5558->reset_gpiod)
+		return;
+
+	gpiod_set_value_cansleep(ak5558->reset_gpiod, 0);
+	usleep_range(1000, 2000);
+}
+
+static void ak5558_power_on(struct ak5558_priv *ak5558)
+{
+	if (!ak5558->reset_gpiod)
+		return;
+
+	gpiod_set_value_cansleep(ak5558->reset_gpiod, 1);
+	usleep_range(1000, 2000);
+}
+
+static int ak5558_probe(struct snd_soc_codec *codec)
+{
+	struct ak5558_priv *ak5558 = snd_soc_codec_get_drvdata(codec);
+
+	ak5558_power_on(ak5558);
+	return ak5558_set_mcki(codec);
+}
+
+static int ak5558_remove(struct snd_soc_codec *codec)
+{
+	struct ak5558_priv *ak5558 = snd_soc_codec_get_drvdata(codec);
+
+	ak5558_power_off(ak5558);
+
+	return 0;
+}
+
+static int __maybe_unused ak5558_runtime_suspend(struct device *dev)
+{
+	struct ak5558_priv *ak5558 = dev_get_drvdata(dev);
+
+	regcache_cache_only(ak5558->regmap, true);
+	ak5558_power_off(ak5558);
+
+	return 0;
+}
+
+static int __maybe_unused ak5558_runtime_resume(struct device *dev)
+{
+	struct ak5558_priv *ak5558 = dev_get_drvdata(dev);
+
+	ak5558_power_off(ak5558);
+	ak5558_power_on(ak5558);
+
+	regcache_cache_only(ak5558->regmap, false);
+	regcache_mark_dirty(ak5558->regmap);
+
+	return regcache_sync(ak5558->regmap);
+}
+
+const struct dev_pm_ops ak5558_pm = {
+	SET_RUNTIME_PM_OPS(ak5558_runtime_suspend, ak5558_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+};
+
+struct snd_soc_codec_driver soc_codec_dev_ak5558 = {
+	.probe = ak5558_probe,
+	.remove = ak5558_remove,
+
+	.component_driver = {
+		.controls = ak5558_snd_controls,
+		.num_controls = ARRAY_SIZE(ak5558_snd_controls),
+		.dapm_widgets = ak5558_dapm_widgets,
+		.num_dapm_widgets = ARRAY_SIZE(ak5558_dapm_widgets),
+		.dapm_routes = ak5558_intercon,
+		.num_dapm_routes = ARRAY_SIZE(ak5558_intercon),
+	},
+};
+
+static const struct regmap_config ak5558_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = AK5558_05_DSD,
+	.reg_defaults = ak5558_reg,
+	.num_reg_defaults = ARRAY_SIZE(ak5558_reg),
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static int ak5558_i2c_probe(struct i2c_client *i2c)
+{
+	struct ak5558_priv *ak5558;
+	int ret = 0;
+
+	ak5558 = devm_kzalloc(&i2c->dev, sizeof(*ak5558), GFP_KERNEL);
+	if (!ak5558)
+		return -ENOMEM;
+
+	ak5558->regmap = devm_regmap_init_i2c(i2c, &ak5558_regmap);
+	if (IS_ERR(ak5558->regmap))
+		return PTR_ERR(ak5558->regmap);
+
+	i2c_set_clientdata(i2c, ak5558);
+	ak5558->i2c = i2c;
+
+	ak5558->reset_gpiod = devm_gpiod_get_optional(&i2c->dev, "reset",
+						      GPIOD_OUT_LOW);
+	if (IS_ERR(ak5558->reset_gpiod))
+		return PTR_ERR(ak5558->reset_gpiod);
+
+	ret = snd_soc_register_codec(&i2c->dev, &soc_codec_dev_ak5558,
+				     &ak5558_dai, 1);
+	if (ret)
+		return ret;
+
+	pm_runtime_enable(&i2c->dev);
+
+	return 0;
+}
+
+static int ak5558_i2c_remove(struct i2c_client *i2c)
+{
+	snd_soc_unregister_codec(&i2c->dev);
+	pm_runtime_disable(&i2c->dev);
+
+	return 0;
+}
+
+static const struct of_device_id ak5558_i2c_dt_ids[] = {
+	{ .compatible = "asahi-kasei,ak5558"},
+	{ }
+};
+
+static struct i2c_driver ak5558_i2c_driver = {
+	.driver = {
+		.name = "ak5558",
+		.of_match_table = of_match_ptr(ak5558_i2c_dt_ids),
+		.pm = &ak5558_pm,
+	},
+	.probe_new = ak5558_i2c_probe,
+	.remove = ak5558_i2c_remove,
+};
+
+module_i2c_driver(ak5558_i2c_driver);
+
+MODULE_AUTHOR("Junichi Wakasugi <wakasugi.jb@om.asahi-kasei.co.jp>");
+MODULE_AUTHOR("Mihai Serban <mihai.serban@nxp.com>");
+MODULE_DESCRIPTION("ASoC AK5558 ADC driver");
+MODULE_LICENSE("GPL v2");