v4.19.13 snapshot.
diff --git a/sound/soc/codecs/wm8728.c b/sound/soc/codecs/wm8728.c
new file mode 100644
index 0000000..839aee3
--- /dev/null
+++ b/sound/soc/codecs/wm8728.c
@@ -0,0 +1,351 @@
+/*
+ * wm8728.c  --  WM8728 ALSA SoC Audio driver
+ *
+ * Copyright 2008 Wolfson Microelectronics plc
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/pm.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/of_device.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/initval.h>
+#include <sound/tlv.h>
+
+#include "wm8728.h"
+
+/*
+ * We can't read the WM8728 register space so we cache them instead.
+ * Note that the defaults here aren't the physical defaults, we latch
+ * the volume update bits, mute the output and enable infinite zero
+ * detect.
+ */
+static const struct reg_default wm8728_reg_defaults[] = {
+	{ 0, 0x1ff },
+	{ 1, 0x1ff },
+	{ 2, 0x001 },
+	{ 3, 0x100 },
+};
+
+/* codec private data */
+struct wm8728_priv {
+	struct regmap *regmap;
+};
+
+static const DECLARE_TLV_DB_SCALE(wm8728_tlv, -12750, 50, 1);
+
+static const struct snd_kcontrol_new wm8728_snd_controls[] = {
+
+SOC_DOUBLE_R_TLV("Digital Playback Volume", WM8728_DACLVOL, WM8728_DACRVOL,
+		 0, 255, 0, wm8728_tlv),
+
+SOC_SINGLE("Deemphasis", WM8728_DACCTL, 1, 1, 0),
+};
+
+/*
+ * DAPM controls.
+ */
+static const struct snd_soc_dapm_widget wm8728_dapm_widgets[] = {
+SND_SOC_DAPM_DAC("DAC", "HiFi Playback", SND_SOC_NOPM, 0, 0),
+SND_SOC_DAPM_OUTPUT("VOUTL"),
+SND_SOC_DAPM_OUTPUT("VOUTR"),
+};
+
+static const struct snd_soc_dapm_route wm8728_intercon[] = {
+	{"VOUTL", NULL, "DAC"},
+	{"VOUTR", NULL, "DAC"},
+};
+
+static int wm8728_mute(struct snd_soc_dai *dai, int mute)
+{
+	struct snd_soc_component *component = dai->component;
+	u16 mute_reg = snd_soc_component_read32(component, WM8728_DACCTL);
+
+	if (mute)
+		snd_soc_component_write(component, WM8728_DACCTL, mute_reg | 1);
+	else
+		snd_soc_component_write(component, WM8728_DACCTL, mute_reg & ~1);
+
+	return 0;
+}
+
+static int wm8728_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;
+	u16 dac = snd_soc_component_read32(component, WM8728_DACCTL);
+
+	dac &= ~0x18;
+
+	switch (params_width(params)) {
+	case 16:
+		break;
+	case 20:
+		dac |= 0x10;
+		break;
+	case 24:
+		dac |= 0x08;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	snd_soc_component_write(component, WM8728_DACCTL, dac);
+
+	return 0;
+}
+
+static int wm8728_set_dai_fmt(struct snd_soc_dai *codec_dai,
+		unsigned int fmt)
+{
+	struct snd_soc_component *component = codec_dai->component;
+	u16 iface = snd_soc_component_read32(component, WM8728_IFCTL);
+
+	/* Currently only I2S is supported by the driver, though the
+	 * hardware is more flexible.
+	 */
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		iface |= 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* The hardware only support full slave mode */
+	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBS_CFS:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_NB_NF:
+		iface &= ~0x22;
+		break;
+	case SND_SOC_DAIFMT_IB_NF:
+		iface |=  0x20;
+		iface &= ~0x02;
+		break;
+	case SND_SOC_DAIFMT_NB_IF:
+		iface |= 0x02;
+		iface &= ~0x20;
+		break;
+	case SND_SOC_DAIFMT_IB_IF:
+		iface |= 0x22;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	snd_soc_component_write(component, WM8728_IFCTL, iface);
+	return 0;
+}
+
+static int wm8728_set_bias_level(struct snd_soc_component *component,
+				 enum snd_soc_bias_level level)
+{
+	struct wm8728_priv *wm8728 = snd_soc_component_get_drvdata(component);
+	u16 reg;
+
+	switch (level) {
+	case SND_SOC_BIAS_ON:
+	case SND_SOC_BIAS_PREPARE:
+	case SND_SOC_BIAS_STANDBY:
+		if (snd_soc_component_get_bias_level(component) == SND_SOC_BIAS_OFF) {
+			/* Power everything up... */
+			reg = snd_soc_component_read32(component, WM8728_DACCTL);
+			snd_soc_component_write(component, WM8728_DACCTL, reg & ~0x4);
+
+			/* ..then sync in the register cache. */
+			regcache_sync(wm8728->regmap);
+		}
+		break;
+
+	case SND_SOC_BIAS_OFF:
+		reg = snd_soc_component_read32(component, WM8728_DACCTL);
+		snd_soc_component_write(component, WM8728_DACCTL, reg | 0x4);
+		break;
+	}
+	return 0;
+}
+
+#define WM8728_RATES (SNDRV_PCM_RATE_8000_192000)
+
+#define WM8728_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE |\
+	SNDRV_PCM_FMTBIT_S24_LE)
+
+static const struct snd_soc_dai_ops wm8728_dai_ops = {
+	.hw_params	= wm8728_hw_params,
+	.digital_mute	= wm8728_mute,
+	.set_fmt	= wm8728_set_dai_fmt,
+};
+
+static struct snd_soc_dai_driver wm8728_dai = {
+	.name = "wm8728-hifi",
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = WM8728_RATES,
+		.formats = WM8728_FORMATS,
+	},
+	.ops = &wm8728_dai_ops,
+};
+
+static const struct snd_soc_component_driver soc_component_dev_wm8728 = {
+	.set_bias_level		= wm8728_set_bias_level,
+	.controls		= wm8728_snd_controls,
+	.num_controls		= ARRAY_SIZE(wm8728_snd_controls),
+	.dapm_widgets		= wm8728_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(wm8728_dapm_widgets),
+	.dapm_routes		= wm8728_intercon,
+	.num_dapm_routes	= ARRAY_SIZE(wm8728_intercon),
+	.suspend_bias_off	= 1,
+	.idle_bias_on		= 1,
+	.use_pmdown_time	= 1,
+	.endianness		= 1,
+	.non_legacy_dai_naming	= 1,
+};
+
+static const struct of_device_id wm8728_of_match[] = {
+	{ .compatible = "wlf,wm8728", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, wm8728_of_match);
+
+static const struct regmap_config wm8728_regmap = {
+	.reg_bits = 7,
+	.val_bits = 9,
+	.max_register = WM8728_IFCTL,
+
+	.reg_defaults = wm8728_reg_defaults,
+	.num_reg_defaults = ARRAY_SIZE(wm8728_reg_defaults),
+	.cache_type = REGCACHE_RBTREE,
+};
+
+#if defined(CONFIG_SPI_MASTER)
+static int wm8728_spi_probe(struct spi_device *spi)
+{
+	struct wm8728_priv *wm8728;
+	int ret;
+
+	wm8728 = devm_kzalloc(&spi->dev, sizeof(struct wm8728_priv),
+			      GFP_KERNEL);
+	if (wm8728 == NULL)
+		return -ENOMEM;
+
+	wm8728->regmap = devm_regmap_init_spi(spi, &wm8728_regmap);
+	if (IS_ERR(wm8728->regmap))
+		return PTR_ERR(wm8728->regmap);
+
+	spi_set_drvdata(spi, wm8728);
+
+	ret = devm_snd_soc_register_component(&spi->dev,
+			&soc_component_dev_wm8728, &wm8728_dai, 1);
+
+	return ret;
+}
+
+static struct spi_driver wm8728_spi_driver = {
+	.driver = {
+		.name	= "wm8728",
+		.of_match_table = wm8728_of_match,
+	},
+	.probe		= wm8728_spi_probe,
+};
+#endif /* CONFIG_SPI_MASTER */
+
+#if IS_ENABLED(CONFIG_I2C)
+static int wm8728_i2c_probe(struct i2c_client *i2c,
+			    const struct i2c_device_id *id)
+{
+	struct wm8728_priv *wm8728;
+	int ret;
+
+	wm8728 = devm_kzalloc(&i2c->dev, sizeof(struct wm8728_priv),
+			      GFP_KERNEL);
+	if (wm8728 == NULL)
+		return -ENOMEM;
+
+	wm8728->regmap = devm_regmap_init_i2c(i2c, &wm8728_regmap);
+	if (IS_ERR(wm8728->regmap))
+		return PTR_ERR(wm8728->regmap);
+
+	i2c_set_clientdata(i2c, wm8728);
+
+	ret =  devm_snd_soc_register_component(&i2c->dev,
+			&soc_component_dev_wm8728, &wm8728_dai, 1);
+
+	return ret;
+}
+
+static const struct i2c_device_id wm8728_i2c_id[] = {
+	{ "wm8728", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, wm8728_i2c_id);
+
+static struct i2c_driver wm8728_i2c_driver = {
+	.driver = {
+		.name = "wm8728",
+		.of_match_table = wm8728_of_match,
+	},
+	.probe =    wm8728_i2c_probe,
+	.id_table = wm8728_i2c_id,
+};
+#endif
+
+static int __init wm8728_modinit(void)
+{
+	int ret = 0;
+#if IS_ENABLED(CONFIG_I2C)
+	ret = i2c_add_driver(&wm8728_i2c_driver);
+	if (ret != 0) {
+		printk(KERN_ERR "Failed to register wm8728 I2C driver: %d\n",
+		       ret);
+	}
+#endif
+#if defined(CONFIG_SPI_MASTER)
+	ret = spi_register_driver(&wm8728_spi_driver);
+	if (ret != 0) {
+		printk(KERN_ERR "Failed to register wm8728 SPI driver: %d\n",
+		       ret);
+	}
+#endif
+	return ret;
+}
+module_init(wm8728_modinit);
+
+static void __exit wm8728_exit(void)
+{
+#if IS_ENABLED(CONFIG_I2C)
+	i2c_del_driver(&wm8728_i2c_driver);
+#endif
+#if defined(CONFIG_SPI_MASTER)
+	spi_unregister_driver(&wm8728_spi_driver);
+#endif
+}
+module_exit(wm8728_exit);
+
+MODULE_DESCRIPTION("ASoC WM8728 driver");
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_LICENSE("GPL");