v4.19.13 snapshot.
diff --git a/sound/soc/codecs/ak4104.c b/sound/soc/codecs/ak4104.c
new file mode 100644
index 0000000..32bc545
--- /dev/null
+++ b/sound/soc/codecs/ak4104.c
@@ -0,0 +1,356 @@
+/*
+ * AK4104 ALSA SoC (ASoC) driver
+ *
+ * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/regulator/consumer.h>
+#include <sound/asoundef.h>
+#include <sound/core.h>
+#include <sound/soc.h>
+#include <sound/initval.h>
+
+/* AK4104 registers addresses */
+#define AK4104_REG_CONTROL1		0x00
+#define AK4104_REG_RESERVED		0x01
+#define AK4104_REG_CONTROL2		0x02
+#define AK4104_REG_TX			0x03
+#define AK4104_REG_CHN_STATUS(x)	((x) + 0x04)
+#define AK4104_NUM_REGS			10
+
+#define AK4104_REG_MASK			0x1f
+#define AK4104_READ			0xc0
+#define AK4104_WRITE			0xe0
+#define AK4104_RESERVED_VAL		0x5b
+
+/* Bit masks for AK4104 registers */
+#define AK4104_CONTROL1_RSTN		(1 << 0)
+#define AK4104_CONTROL1_PW		(1 << 1)
+#define AK4104_CONTROL1_DIF0		(1 << 2)
+#define AK4104_CONTROL1_DIF1		(1 << 3)
+
+#define AK4104_CONTROL2_SEL0		(1 << 0)
+#define AK4104_CONTROL2_SEL1		(1 << 1)
+#define AK4104_CONTROL2_MODE		(1 << 2)
+
+#define AK4104_TX_TXE			(1 << 0)
+#define AK4104_TX_V			(1 << 1)
+
+struct ak4104_private {
+	struct regmap *regmap;
+	struct regulator *regulator;
+};
+
+static const struct snd_soc_dapm_widget ak4104_dapm_widgets[] = {
+SND_SOC_DAPM_PGA("TXE", AK4104_REG_TX, AK4104_TX_TXE, 0, NULL, 0),
+
+SND_SOC_DAPM_OUTPUT("TX"),
+};
+
+static const struct snd_soc_dapm_route ak4104_dapm_routes[] = {
+	{ "TXE", NULL, "Playback" },
+	{ "TX", NULL, "TXE" },
+};
+
+static int ak4104_set_dai_fmt(struct snd_soc_dai *codec_dai,
+			      unsigned int format)
+{
+	struct snd_soc_component *component = codec_dai->component;
+	struct ak4104_private *ak4104 = snd_soc_component_get_drvdata(component);
+	int val = 0;
+	int ret;
+
+	/* set DAI format */
+	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_RIGHT_J:
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		val |= AK4104_CONTROL1_DIF0;
+		break;
+	case SND_SOC_DAIFMT_I2S:
+		val |= AK4104_CONTROL1_DIF0 | AK4104_CONTROL1_DIF1;
+		break;
+	default:
+		dev_err(component->dev, "invalid dai format\n");
+		return -EINVAL;
+	}
+
+	/* This device can only be slave */
+	if ((format & SND_SOC_DAIFMT_MASTER_MASK) != SND_SOC_DAIFMT_CBS_CFS)
+		return -EINVAL;
+
+	ret = regmap_update_bits(ak4104->regmap, AK4104_REG_CONTROL1,
+				 AK4104_CONTROL1_DIF0 | AK4104_CONTROL1_DIF1,
+				 val);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ak4104_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 ak4104_private *ak4104 = snd_soc_component_get_drvdata(component);
+	int ret, val = 0;
+
+	/* set the IEC958 bits: consumer mode, no copyright bit */
+	val |= IEC958_AES0_CON_NOT_COPYRIGHT;
+	regmap_write(ak4104->regmap, AK4104_REG_CHN_STATUS(0), val);
+
+	val = 0;
+
+	switch (params_rate(params)) {
+	case 22050:
+		val |= IEC958_AES3_CON_FS_22050;
+		break;
+	case 24000:
+		val |= IEC958_AES3_CON_FS_24000;
+		break;
+	case 32000:
+		val |= IEC958_AES3_CON_FS_32000;
+		break;
+	case 44100:
+		val |= IEC958_AES3_CON_FS_44100;
+		break;
+	case 48000:
+		val |= IEC958_AES3_CON_FS_48000;
+		break;
+	case 88200:
+		val |= IEC958_AES3_CON_FS_88200;
+		break;
+	case 96000:
+		val |= IEC958_AES3_CON_FS_96000;
+		break;
+	case 176400:
+		val |= IEC958_AES3_CON_FS_176400;
+		break;
+	case 192000:
+		val |= IEC958_AES3_CON_FS_192000;
+		break;
+	default:
+		dev_err(component->dev, "unsupported sampling rate\n");
+		return -EINVAL;
+	}
+
+	ret = regmap_write(ak4104->regmap, AK4104_REG_CHN_STATUS(3), val);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops ak4101_dai_ops = {
+	.hw_params = ak4104_hw_params,
+	.set_fmt = ak4104_set_dai_fmt,
+};
+
+static struct snd_soc_dai_driver ak4104_dai = {
+	.name = "ak4104-hifi",
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 |
+			 SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
+			 SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 |
+			 SNDRV_PCM_RATE_176400 | SNDRV_PCM_RATE_192000,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE  |
+			   SNDRV_PCM_FMTBIT_S24_3LE |
+			   SNDRV_PCM_FMTBIT_S24_LE
+	},
+	.ops = &ak4101_dai_ops,
+};
+
+static int ak4104_probe(struct snd_soc_component *component)
+{
+	struct ak4104_private *ak4104 = snd_soc_component_get_drvdata(component);
+	int ret;
+
+	ret = regulator_enable(ak4104->regulator);
+	if (ret < 0) {
+		dev_err(component->dev, "Unable to enable regulator: %d\n", ret);
+		return ret;
+	}
+
+	/* set power-up and non-reset bits */
+	ret = regmap_update_bits(ak4104->regmap, AK4104_REG_CONTROL1,
+				 AK4104_CONTROL1_PW | AK4104_CONTROL1_RSTN,
+				 AK4104_CONTROL1_PW | AK4104_CONTROL1_RSTN);
+	if (ret < 0)
+		goto exit_disable_regulator;
+
+	/* enable transmitter */
+	ret = regmap_update_bits(ak4104->regmap, AK4104_REG_TX,
+				 AK4104_TX_TXE, AK4104_TX_TXE);
+	if (ret < 0)
+		goto exit_disable_regulator;
+
+	return 0;
+
+exit_disable_regulator:
+	regulator_disable(ak4104->regulator);
+	return ret;
+}
+
+static void ak4104_remove(struct snd_soc_component *component)
+{
+	struct ak4104_private *ak4104 = snd_soc_component_get_drvdata(component);
+
+	regmap_update_bits(ak4104->regmap, AK4104_REG_CONTROL1,
+			   AK4104_CONTROL1_PW | AK4104_CONTROL1_RSTN, 0);
+	regulator_disable(ak4104->regulator);
+}
+
+#ifdef CONFIG_PM
+static int ak4104_soc_suspend(struct snd_soc_component *component)
+{
+	struct ak4104_private *priv = snd_soc_component_get_drvdata(component);
+
+	regulator_disable(priv->regulator);
+
+	return 0;
+}
+
+static int ak4104_soc_resume(struct snd_soc_component *component)
+{
+	struct ak4104_private *priv = snd_soc_component_get_drvdata(component);
+	int ret;
+
+	ret = regulator_enable(priv->regulator);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+#else
+#define ak4104_soc_suspend	NULL
+#define ak4104_soc_resume	NULL
+#endif /* CONFIG_PM */
+
+static const struct snd_soc_component_driver soc_component_device_ak4104 = {
+	.probe			= ak4104_probe,
+	.remove			= ak4104_remove,
+	.suspend		= ak4104_soc_suspend,
+	.resume			= ak4104_soc_resume,
+	.dapm_widgets		= ak4104_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(ak4104_dapm_widgets),
+	.dapm_routes		= ak4104_dapm_routes,
+	.num_dapm_routes	= ARRAY_SIZE(ak4104_dapm_routes),
+	.idle_bias_on		= 1,
+	.use_pmdown_time	= 1,
+	.endianness		= 1,
+	.non_legacy_dai_naming	= 1,
+};
+
+static const struct regmap_config ak4104_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = AK4104_NUM_REGS - 1,
+	.read_flag_mask = AK4104_READ,
+	.write_flag_mask = AK4104_WRITE,
+
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static int ak4104_spi_probe(struct spi_device *spi)
+{
+	struct device_node *np = spi->dev.of_node;
+	struct ak4104_private *ak4104;
+	unsigned int val;
+	int ret;
+
+	spi->bits_per_word = 8;
+	spi->mode = SPI_MODE_0;
+	ret = spi_setup(spi);
+	if (ret < 0)
+		return ret;
+
+	ak4104 = devm_kzalloc(&spi->dev, sizeof(struct ak4104_private),
+			      GFP_KERNEL);
+	if (ak4104 == NULL)
+		return -ENOMEM;
+
+	ak4104->regulator = devm_regulator_get(&spi->dev, "vdd");
+	if (IS_ERR(ak4104->regulator)) {
+		ret = PTR_ERR(ak4104->regulator);
+		dev_err(&spi->dev, "Unable to get Vdd regulator: %d\n", ret);
+		return ret;
+	}
+
+	ak4104->regmap = devm_regmap_init_spi(spi, &ak4104_regmap);
+	if (IS_ERR(ak4104->regmap)) {
+		ret = PTR_ERR(ak4104->regmap);
+		return ret;
+	}
+
+	if (np) {
+		enum of_gpio_flags flags;
+		int gpio = of_get_named_gpio_flags(np, "reset-gpio", 0, &flags);
+
+		if (gpio_is_valid(gpio)) {
+			ret = devm_gpio_request_one(&spi->dev, gpio,
+				     flags & OF_GPIO_ACTIVE_LOW ?
+					GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH,
+				     "ak4104 reset");
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	/* read the 'reserved' register - according to the datasheet, it
+	 * should contain 0x5b. Not a good way to verify the presence of
+	 * the device, but there is no hardware ID register. */
+	ret = regmap_read(ak4104->regmap, AK4104_REG_RESERVED, &val);
+	if (ret != 0)
+		return ret;
+	if (val != AK4104_RESERVED_VAL)
+		return -ENODEV;
+
+	spi_set_drvdata(spi, ak4104);
+
+	ret = devm_snd_soc_register_component(&spi->dev,
+			&soc_component_device_ak4104, &ak4104_dai, 1);
+	return ret;
+}
+
+static const struct of_device_id ak4104_of_match[] = {
+	{ .compatible = "asahi-kasei,ak4104", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ak4104_of_match);
+
+static const struct spi_device_id ak4104_id_table[] = {
+	{ "ak4104", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ak4104_id_table);
+
+static struct spi_driver ak4104_spi_driver = {
+	.driver  = {
+		.name   = "ak4104",
+		.of_match_table = ak4104_of_match,
+	},
+	.id_table = ak4104_id_table,
+	.probe  = ak4104_spi_probe,
+};
+
+module_spi_driver(ak4104_spi_driver);
+
+MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
+MODULE_DESCRIPTION("Asahi Kasei AK4104 ALSA SoC driver");
+MODULE_LICENSE("GPL");
+