Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 766 insertions, 0 deletions

diff --git a/kernel/sound/soc/codecs/cs4270.c b/kernel/sound/soc/codecs/cs4270.c
new file mode 100644
index 000000000..e6d4ff9fd
--- /dev/null
+++ b/kernel/sound/soc/codecs/cs4270.c
@@ -0,0 +1,766 @@
+/*
+ * CS4270 ALSA SoC (ASoC) codec driver
+ *
+ * Author: Timur Tabi <timur@freescale.com>
+ *
+ * Copyright 2007-2009 Freescale Semiconductor, Inc.  This file is licensed
+ * under the terms of the GNU General Public License version 2.  This
+ * program is licensed "as is" without any warranty of any kind, whether
+ * express or implied.
+ *
+ * This is an ASoC device driver for the Cirrus Logic CS4270 codec.
+ *
+ * Current features/limitations:
+ *
+ * - Software mode is supported.  Stand-alone mode is not supported.
+ * - Only I2C is supported, not SPI
+ * - Support for master and slave mode
+ * - The machine driver's 'startup' function must call
+ *   cs4270_set_dai_sysclk() with the value of MCLK.
+ * - Only I2S and left-justified modes are supported
+ * - Power management is supported
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <sound/soc.h>
+#include <sound/initval.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/regulator/consumer.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+
+/*
+ * The codec isn't really big-endian or little-endian, since the I2S
+ * interface requires data to be sent serially with the MSbit first.
+ * However, to support BE and LE I2S devices, we specify both here.  That
+ * way, ALSA will always match the bit patterns.
+ */
+#define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | \
+			SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_S16_BE  | \
+			SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \
+			SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \
+			SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
+			SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
+
+/* CS4270 registers addresses */
+#define CS4270_CHIPID	0x01	/* Chip ID */
+#define CS4270_PWRCTL	0x02	/* Power Control */
+#define CS4270_MODE	0x03	/* Mode Control */
+#define CS4270_FORMAT	0x04	/* Serial Format, ADC/DAC Control */
+#define CS4270_TRANS	0x05	/* Transition Control */
+#define CS4270_MUTE	0x06	/* Mute Control */
+#define CS4270_VOLA	0x07	/* DAC Channel A Volume Control */
+#define CS4270_VOLB	0x08	/* DAC Channel B Volume Control */
+
+#define CS4270_FIRSTREG	0x01
+#define CS4270_LASTREG	0x08
+#define CS4270_NUMREGS	(CS4270_LASTREG - CS4270_FIRSTREG + 1)
+#define CS4270_I2C_INCR	0x80
+
+/* Bit masks for the CS4270 registers */
+#define CS4270_CHIPID_ID	0xF0
+#define CS4270_CHIPID_REV	0x0F
+#define CS4270_PWRCTL_FREEZE	0x80
+#define CS4270_PWRCTL_PDN_ADC	0x20
+#define CS4270_PWRCTL_PDN_DAC	0x02
+#define CS4270_PWRCTL_PDN	0x01
+#define CS4270_PWRCTL_PDN_ALL	\
+	(CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)
+#define CS4270_MODE_SPEED_MASK	0x30
+#define CS4270_MODE_1X		0x00
+#define CS4270_MODE_2X		0x10
+#define CS4270_MODE_4X		0x20
+#define CS4270_MODE_SLAVE	0x30
+#define CS4270_MODE_DIV_MASK	0x0E
+#define CS4270_MODE_DIV1	0x00
+#define CS4270_MODE_DIV15	0x02
+#define CS4270_MODE_DIV2	0x04
+#define CS4270_MODE_DIV3	0x06
+#define CS4270_MODE_DIV4	0x08
+#define CS4270_MODE_POPGUARD	0x01
+#define CS4270_FORMAT_FREEZE_A	0x80
+#define CS4270_FORMAT_FREEZE_B	0x40
+#define CS4270_FORMAT_LOOPBACK	0x20
+#define CS4270_FORMAT_DAC_MASK	0x18
+#define CS4270_FORMAT_DAC_LJ	0x00
+#define CS4270_FORMAT_DAC_I2S	0x08
+#define CS4270_FORMAT_DAC_RJ16	0x18
+#define CS4270_FORMAT_DAC_RJ24	0x10
+#define CS4270_FORMAT_ADC_MASK	0x01
+#define CS4270_FORMAT_ADC_LJ	0x00
+#define CS4270_FORMAT_ADC_I2S	0x01
+#define CS4270_TRANS_ONE_VOL	0x80
+#define CS4270_TRANS_SOFT	0x40
+#define CS4270_TRANS_ZERO	0x20
+#define CS4270_TRANS_INV_ADC_A	0x08
+#define CS4270_TRANS_INV_ADC_B	0x10
+#define CS4270_TRANS_INV_DAC_A	0x02
+#define CS4270_TRANS_INV_DAC_B	0x04
+#define CS4270_TRANS_DEEMPH	0x01
+#define CS4270_MUTE_AUTO	0x20
+#define CS4270_MUTE_ADC_A	0x08
+#define CS4270_MUTE_ADC_B	0x10
+#define CS4270_MUTE_POLARITY	0x04
+#define CS4270_MUTE_DAC_A	0x01
+#define CS4270_MUTE_DAC_B	0x02
+
+/* Power-on default values for the registers
+ *
+ * This array contains the power-on default values of the registers, with the
+ * exception of the "CHIPID" register (01h).  The lower four bits of that
+ * register contain the hardware revision, so it is treated as volatile.
+ */
+static const struct reg_default cs4270_reg_defaults[] = {
+	{ 2, 0x00 },
+	{ 3, 0x30 },
+	{ 4, 0x00 },
+	{ 5, 0x60 },
+	{ 6, 0x20 },
+	{ 7, 0x00 },
+	{ 8, 0x00 },
+};
+
+static const char *supply_names[] = {
+	"va", "vd", "vlc"
+};
+
+/* Private data for the CS4270 */
+struct cs4270_private {
+	struct regmap *regmap;
+	unsigned int mclk; /* Input frequency of the MCLK pin */
+	unsigned int mode; /* The mode (I2S or left-justified) */
+	unsigned int slave_mode;
+	unsigned int manual_mute;
+
+	/* power domain regulators */
+	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
+};
+
+static const struct snd_soc_dapm_widget cs4270_dapm_widgets[] = {
+SND_SOC_DAPM_INPUT("AINL"),
+SND_SOC_DAPM_INPUT("AINR"),
+
+SND_SOC_DAPM_OUTPUT("AOUTL"),
+SND_SOC_DAPM_OUTPUT("AOUTR"),
+};
+
+static const struct snd_soc_dapm_route cs4270_dapm_routes[] = {
+	{ "Capture", NULL, "AINA" },
+	{ "Capture", NULL, "AINB" },
+
+	{ "AOUTA", NULL, "Playback" },
+	{ "AOUTB", NULL, "Playback" },
+};
+
+/**
+ * struct cs4270_mode_ratios - clock ratio tables
+ * @ratio: the ratio of MCLK to the sample rate
+ * @speed_mode: the Speed Mode bits to set in the Mode Control register for
+ *              this ratio
+ * @mclk: the Ratio Select bits to set in the Mode Control register for this
+ *        ratio
+ *
+ * The data for this chart is taken from Table 5 of the CS4270 reference
+ * manual.
+ *
+ * This table is used to determine how to program the Mode Control register.
+ * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
+ * rates the CS4270 currently supports.
+ *
+ * @speed_mode is the corresponding bit pattern to be written to the
+ * MODE bits of the Mode Control Register
+ *
+ * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of
+ * the Mode Control Register.
+ *
+ * In situations where a single ratio is represented by multiple speed
+ * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
+ * double-speed instead of quad-speed.  However, the CS4270 errata states
+ * that divide-By-1.5 can cause failures, so we avoid that mode where
+ * possible.
+ *
+ * Errata: There is an errata for the CS4270 where divide-by-1.5 does not
+ * work if Vd is 3.3V.  If this effects you, select the
+ * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
+ * never select any sample rates that require divide-by-1.5.
+ */
+struct cs4270_mode_ratios {
+	unsigned int ratio;
+	u8 speed_mode;
+	u8 mclk;
+};
+
+static struct cs4270_mode_ratios cs4270_mode_ratios[] = {
+	{64, CS4270_MODE_4X, CS4270_MODE_DIV1},
+#ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
+	{96, CS4270_MODE_4X, CS4270_MODE_DIV15},
+#endif
+	{128, CS4270_MODE_2X, CS4270_MODE_DIV1},
+	{192, CS4270_MODE_4X, CS4270_MODE_DIV3},
+	{256, CS4270_MODE_1X, CS4270_MODE_DIV1},
+	{384, CS4270_MODE_2X, CS4270_MODE_DIV3},
+	{512, CS4270_MODE_1X, CS4270_MODE_DIV2},
+	{768, CS4270_MODE_1X, CS4270_MODE_DIV3},
+	{1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
+};
+
+/* The number of MCLK/LRCK ratios supported by the CS4270 */
+#define NUM_MCLK_RATIOS		ARRAY_SIZE(cs4270_mode_ratios)
+
+static bool cs4270_reg_is_readable(struct device *dev, unsigned int reg)
+{
+	return (reg >= CS4270_FIRSTREG) && (reg <= CS4270_LASTREG);
+}
+
+static bool cs4270_reg_is_volatile(struct device *dev, unsigned int reg)
+{
+	/* Unreadable registers are considered volatile */
+	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
+		return 1;
+
+	return reg == CS4270_CHIPID;
+}
+
+/**
+ * cs4270_set_dai_sysclk - determine the CS4270 samples rates.
+ * @codec_dai: the codec DAI
+ * @clk_id: the clock ID (ignored)
+ * @freq: the MCLK input frequency
+ * @dir: the clock direction (ignored)
+ *
+ * This function is used to tell the codec driver what the input MCLK
+ * frequency is.
+ *
+ * The value of MCLK is used to determine which sample rates are supported
+ * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
+ * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
+ *
+ * This function calculates the nine ratios and determines which ones match
+ * a standard sample rate.  If there's a match, then it is added to the list
+ * of supported sample rates.
+ *
+ * This function must be called by the machine driver's 'startup' function,
+ * otherwise the list of supported sample rates will not be available in
+ * time for ALSA.
+ *
+ * For setups with variable MCLKs, pass 0 as 'freq' argument. This will cause
+ * theoretically possible sample rates to be enabled. Call it again with a
+ * proper value set one the external clock is set (most probably you would do
+ * that from a machine's driver 'hw_param' hook.
+ */
+static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
+				 int clk_id, unsigned int freq, int dir)
+{
+	struct snd_soc_codec *codec = codec_dai->codec;
+	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
+
+	cs4270->mclk = freq;
+	return 0;
+}
+
+/**
+ * cs4270_set_dai_fmt - configure the codec for the selected audio format
+ * @codec_dai: the codec DAI
+ * @format: a SND_SOC_DAIFMT_x value indicating the data format
+ *
+ * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
+ * codec accordingly.
+ *
+ * Currently, this function only supports SND_SOC_DAIFMT_I2S and
+ * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
+ * data for playback only, but ASoC currently does not support different
+ * formats for playback vs. record.
+ */
+static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
+			      unsigned int format)
+{
+	struct snd_soc_codec *codec = codec_dai->codec;
+	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
+
+	/* set DAI format */
+	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+	case SND_SOC_DAIFMT_LEFT_J:
+		cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
+		break;
+	default:
+		dev_err(codec->dev, "invalid dai format\n");
+		return -EINVAL;
+	}
+
+	/* set master/slave audio interface */
+	switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBS_CFS:
+		cs4270->slave_mode = 1;
+		break;
+	case SND_SOC_DAIFMT_CBM_CFM:
+		cs4270->slave_mode = 0;
+		break;
+	default:
+		/* all other modes are unsupported by the hardware */
+		dev_err(codec->dev, "Unknown master/slave configuration\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * cs4270_hw_params - program the CS4270 with the given hardware parameters.
+ * @substream: the audio stream
+ * @params: the hardware parameters to set
+ * @dai: the SOC DAI (ignored)
+ *
+ * This function programs the hardware with the values provided.
+ * Specifically, the sample rate and the data format.
+ *
+ * The .ops functions are used to provide board-specific data, like input
+ * frequencies, to this driver.  This function takes that information,
+ * combines it with the hardware parameters provided, and programs the
+ * hardware accordingly.
+ */
+static int cs4270_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 cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
+	int ret;
+	unsigned int i;
+	unsigned int rate;
+	unsigned int ratio;
+	int reg;
+
+	/* Figure out which MCLK/LRCK ratio to use */
+
+	rate = params_rate(params);	/* Sampling rate, in Hz */
+	ratio = cs4270->mclk / rate;	/* MCLK/LRCK ratio */
+
+	for (i = 0; i < NUM_MCLK_RATIOS; i++) {
+		if (cs4270_mode_ratios[i].ratio == ratio)
+			break;
+	}
+
+	if (i == NUM_MCLK_RATIOS) {
+		/* We did not find a matching ratio */
+		dev_err(codec->dev, "could not find matching ratio\n");
+		return -EINVAL;
+	}
+
+	/* Set the sample rate */
+
+	reg = snd_soc_read(codec, CS4270_MODE);
+	reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
+	reg |= cs4270_mode_ratios[i].mclk;
+
+	if (cs4270->slave_mode)
+		reg |= CS4270_MODE_SLAVE;
+	else
+		reg |= cs4270_mode_ratios[i].speed_mode;
+
+	ret = snd_soc_write(codec, CS4270_MODE, reg);
+	if (ret < 0) {
+		dev_err(codec->dev, "i2c write failed\n");
+		return ret;
+	}
+
+	/* Set the DAI format */
+
+	reg = snd_soc_read(codec, CS4270_FORMAT);
+	reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
+
+	switch (cs4270->mode) {
+	case SND_SOC_DAIFMT_I2S:
+		reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
+		break;
+	default:
+		dev_err(codec->dev, "unknown dai format\n");
+		return -EINVAL;
+	}
+
+	ret = snd_soc_write(codec, CS4270_FORMAT, reg);
+	if (ret < 0) {
+		dev_err(codec->dev, "i2c write failed\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+/**
+ * cs4270_dai_mute - enable/disable the CS4270 external mute
+ * @dai: the SOC DAI
+ * @mute: 0 = disable mute, 1 = enable mute
+ *
+ * This function toggles the mute bits in the MUTE register.  The CS4270's
+ * mute capability is intended for external muting circuitry, so if the
+ * board does not have the MUTEA or MUTEB pins connected to such circuitry,
+ * then this function will do nothing.
+ */
+static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
+	int reg6;
+
+	reg6 = snd_soc_read(codec, CS4270_MUTE);
+
+	if (mute)
+		reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
+	else {
+		reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
+		reg6 |= cs4270->manual_mute;
+	}
+
+	return snd_soc_write(codec, CS4270_MUTE, reg6);
+}
+
+/**
+ * cs4270_soc_put_mute - put callback for the 'Master Playback switch'
+ * 			 alsa control.
+ * @kcontrol: mixer control
+ * @ucontrol: control element information
+ *
+ * This function basically passes the arguments on to the generic
+ * snd_soc_put_volsw() function and saves the mute information in
+ * our private data structure. This is because we want to prevent
+ * cs4270_dai_mute() neglecting the user's decision to manually
+ * mute the codec's output.
+ *
+ * Returns 0 for success.
+ */
+static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
+	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
+	int left = !ucontrol->value.integer.value[0];
+	int right = !ucontrol->value.integer.value[1];
+
+	cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |
+			      (right ? CS4270_MUTE_DAC_B : 0);
+
+	return snd_soc_put_volsw(kcontrol, ucontrol);
+}
+
+/* A list of non-DAPM controls that the CS4270 supports */
+static const struct snd_kcontrol_new cs4270_snd_controls[] = {
+	SOC_DOUBLE_R("Master Playback Volume",
+		CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),
+	SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),
+	SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),
+	SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),
+	SOC_SINGLE("De-emphasis filter", CS4270_TRANS, 0, 1, 0),
+	SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),
+	SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),
+	SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),
+	SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,
+		snd_soc_get_volsw, cs4270_soc_put_mute),
+};
+
+static const struct snd_soc_dai_ops cs4270_dai_ops = {
+	.hw_params	= cs4270_hw_params,
+	.set_sysclk	= cs4270_set_dai_sysclk,
+	.set_fmt	= cs4270_set_dai_fmt,
+	.digital_mute	= cs4270_dai_mute,
+};
+
+static struct snd_soc_dai_driver cs4270_dai = {
+	.name = "cs4270-hifi",
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.rate_min = 4000,
+		.rate_max = 216000,
+		.formats = CS4270_FORMATS,
+	},
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.rate_min = 4000,
+		.rate_max = 216000,
+		.formats = CS4270_FORMATS,
+	},
+	.ops = &cs4270_dai_ops,
+};
+
+/**
+ * cs4270_probe - ASoC probe function
+ * @pdev: platform device
+ *
+ * This function is called when ASoC has all the pieces it needs to
+ * instantiate a sound driver.
+ */
+static int cs4270_probe(struct snd_soc_codec *codec)
+{
+	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
+	int ret;
+
+	/* Disable auto-mute.  This feature appears to be buggy.  In some
+	 * situations, auto-mute will not deactivate when it should, so we want
+	 * this feature disabled by default.  An application (e.g. alsactl) can
+	 * re-enabled it by using the controls.
+	 */
+	ret = snd_soc_update_bits(codec, CS4270_MUTE, CS4270_MUTE_AUTO, 0);
+	if (ret < 0) {
+		dev_err(codec->dev, "i2c write failed\n");
+		return ret;
+	}
+
+	/* Disable automatic volume control.  The hardware enables, and it
+	 * causes volume change commands to be delayed, sometimes until after
+	 * playback has started.  An application (e.g. alsactl) can
+	 * re-enabled it by using the controls.
+	 */
+	ret = snd_soc_update_bits(codec, CS4270_TRANS,
+		CS4270_TRANS_SOFT | CS4270_TRANS_ZERO, 0);
+	if (ret < 0) {
+		dev_err(codec->dev, "i2c write failed\n");
+		return ret;
+	}
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
+				    cs4270->supplies);
+
+	return ret;
+}
+
+/**
+ * cs4270_remove - ASoC remove function
+ * @pdev: platform device
+ *
+ * This function is the counterpart to cs4270_probe().
+ */
+static int cs4270_remove(struct snd_soc_codec *codec)
+{
+	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
+
+	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
+
+	return 0;
+};
+
+#ifdef CONFIG_PM
+
+/* This suspend/resume implementation can handle both - a simple standby
+ * where the codec remains powered, and a full suspend, where the voltage
+ * domain the codec is connected to is teared down and/or any other hardware
+ * reset condition is asserted.
+ *
+ * The codec's own power saving features are enabled in the suspend callback,
+ * and all registers are written back to the hardware when resuming.
+ */
+
+static int cs4270_soc_suspend(struct snd_soc_codec *codec)
+{
+	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
+	int reg, ret;
+
+	reg = snd_soc_read(codec, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;
+	if (reg < 0)
+		return reg;
+
+	ret = snd_soc_write(codec, CS4270_PWRCTL, reg);
+	if (ret < 0)
+		return ret;
+
+	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies),
+			       cs4270->supplies);
+
+	return 0;
+}
+
+static int cs4270_soc_resume(struct snd_soc_codec *codec)
+{
+	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
+	int reg, ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
+				    cs4270->supplies);
+	if (ret != 0)
+		return ret;
+
+	/* In case the device was put to hard reset during sleep, we need to
+	 * wait 500ns here before any I2C communication. */
+	ndelay(500);
+
+	/* first restore the entire register cache ... */
+	regcache_sync(cs4270->regmap);
+
+	/* ... then disable the power-down bits */
+	reg = snd_soc_read(codec, CS4270_PWRCTL);
+	reg &= ~CS4270_PWRCTL_PDN_ALL;
+
+	return snd_soc_write(codec, CS4270_PWRCTL, reg);
+}
+#else
+#define cs4270_soc_suspend	NULL
+#define cs4270_soc_resume	NULL
+#endif /* CONFIG_PM */
+
+/*
+ * ASoC codec driver structure
+ */
+static const struct snd_soc_codec_driver soc_codec_device_cs4270 = {
+	.probe =		cs4270_probe,
+	.remove =		cs4270_remove,
+	.suspend =		cs4270_soc_suspend,
+	.resume =		cs4270_soc_resume,
+
+	.controls =		cs4270_snd_controls,
+	.num_controls =		ARRAY_SIZE(cs4270_snd_controls),
+	.dapm_widgets =		cs4270_dapm_widgets,
+	.num_dapm_widgets =	ARRAY_SIZE(cs4270_dapm_widgets),
+	.dapm_routes =		cs4270_dapm_routes,
+	.num_dapm_routes =	ARRAY_SIZE(cs4270_dapm_routes),
+};
+
+/*
+ * cs4270_of_match - the device tree bindings
+ */
+static const struct of_device_id cs4270_of_match[] = {
+	{ .compatible = "cirrus,cs4270", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, cs4270_of_match);
+
+static const struct regmap_config cs4270_regmap = {
+	.reg_bits =		8,
+	.val_bits =		8,
+	.max_register =		CS4270_LASTREG,
+	.reg_defaults =		cs4270_reg_defaults,
+	.num_reg_defaults =	ARRAY_SIZE(cs4270_reg_defaults),
+	.cache_type =		REGCACHE_RBTREE,
+
+	.readable_reg =		cs4270_reg_is_readable,
+	.volatile_reg =		cs4270_reg_is_volatile,
+};
+
+/**
+ * cs4270_i2c_probe - initialize the I2C interface of the CS4270
+ * @i2c_client: the I2C client object
+ * @id: the I2C device ID (ignored)
+ *
+ * This function is called whenever the I2C subsystem finds a device that
+ * matches the device ID given via a prior call to i2c_add_driver().
+ */
+static int cs4270_i2c_probe(struct i2c_client *i2c_client,
+	const struct i2c_device_id *id)
+{
+	struct device_node *np = i2c_client->dev.of_node;
+	struct cs4270_private *cs4270;
+	unsigned int val;
+	int ret, i;
+
+	cs4270 = devm_kzalloc(&i2c_client->dev, sizeof(struct cs4270_private),
+			      GFP_KERNEL);
+	if (!cs4270)
+		return -ENOMEM;
+
+	/* get the power supply regulators */
+	for (i = 0; i < ARRAY_SIZE(supply_names); i++)
+		cs4270->supplies[i].supply = supply_names[i];
+
+	ret = devm_regulator_bulk_get(&i2c_client->dev,
+				      ARRAY_SIZE(cs4270->supplies),
+				      cs4270->supplies);
+	if (ret < 0)
+		return ret;
+
+	/* See if we have a way to bring the codec out of reset */
+	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(&i2c_client->dev, gpio,
+				     flags & OF_GPIO_ACTIVE_LOW ?
+					GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH,
+				     "cs4270 reset");
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	cs4270->regmap = devm_regmap_init_i2c(i2c_client, &cs4270_regmap);
+	if (IS_ERR(cs4270->regmap))
+		return PTR_ERR(cs4270->regmap);
+
+	/* Verify that we have a CS4270 */
+	ret = regmap_read(cs4270->regmap, CS4270_CHIPID, &val);
+	if (ret < 0) {
+		dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",
+		       i2c_client->addr);
+		return ret;
+	}
+	/* The top four bits of the chip ID should be 1100. */
+	if ((val & 0xF0) != 0xC0) {
+		dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",
+		       i2c_client->addr);
+		return -ENODEV;
+	}
+
+	dev_info(&i2c_client->dev, "found device at i2c address %X\n",
+		i2c_client->addr);
+	dev_info(&i2c_client->dev, "hardware revision %X\n", val & 0xF);
+
+	i2c_set_clientdata(i2c_client, cs4270);
+
+	ret = snd_soc_register_codec(&i2c_client->dev,
+			&soc_codec_device_cs4270, &cs4270_dai, 1);
+	return ret;
+}
+
+/**
+ * cs4270_i2c_remove - remove an I2C device
+ * @i2c_client: the I2C client object
+ *
+ * This function is the counterpart to cs4270_i2c_probe().
+ */
+static int cs4270_i2c_remove(struct i2c_client *i2c_client)
+{
+	snd_soc_unregister_codec(&i2c_client->dev);
+	return 0;
+}
+
+/*
+ * cs4270_id - I2C device IDs supported by this driver
+ */
+static const struct i2c_device_id cs4270_id[] = {
+	{"cs4270", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, cs4270_id);
+
+/*
+ * cs4270_i2c_driver - I2C device identification
+ *
+ * This structure tells the I2C subsystem how to identify and support a
+ * given I2C device type.
+ */
+static struct i2c_driver cs4270_i2c_driver = {
+	.driver = {
+		.name = "cs4270",
+		.owner = THIS_MODULE,
+		.of_match_table = cs4270_of_match,
+	},
+	.id_table = cs4270_id,
+	.probe = cs4270_i2c_probe,
+	.remove = cs4270_i2c_remove,
+};
+
+module_i2c_driver(cs4270_i2c_driver);
+
+MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
+MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
+MODULE_LICENSE("GPL");