[ALSA] ASoC codecs: WM8731 support

This patch adds ASoC support for the WM8731 codec.
Supported features:-
 o Capture/Playback/Sidetone/Bypass.
 o 16 & 24 bit audio.
 o 8k - 96k sample rates.
 o DAPM.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

3 files changed, 831 insertions, 0 deletions

diff --git a/include/linux/i2c-id.h b/include/linux/i2c-id.h
index d38778f2fbec..01e98c2a9618 100644
--- a/include/linux/i2c-id.h
+++ b/include/linux/i2c-id.h
@@ -115,6 +115,7 @@
 #define I2C_DRIVERID_KS0127	86	/* Samsung ks0127 video decoder */
 #define I2C_DRIVERID_TLV320AIC23B 87	/* TI TLV320AIC23B audio codec  */
 #define I2C_DRIVERID_ISL1208	88	/* Intersil ISL1208 RTC		*/
+#define I2C_DRIVERID_WM8731		89	/* Wolfson WM8731 audio codec */
 
 #define I2C_DRIVERID_I2CDEV	900
 #define I2C_DRIVERID_ARP        902    /* SMBus ARP Client              */
diff --git a/sound/soc/codecs/wm8731.c b/sound/soc/codecs/wm8731.c
new file mode 100644
index 000000000000..cd0ece650f31
--- /dev/null
+++ b/sound/soc/codecs/wm8731.c
@@ -0,0 +1,789 @@
+/*
+ * wm8731.c  --  WM8731 ALSA SoC Audio driver
+ *
+ * Copyright 2005 Openedhand Ltd.
+ *
+ * Author: Richard Purdie <richard@openedhand.com>
+ *
+ * Based on wm8753.c by Liam Girdwood
+ *
+ * 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 <sound/driver.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/soc-dapm.h>
+#include <sound/initval.h>
+
+#include "wm8731.h"
+
+#define AUDIO_NAME "wm8731"
+#define WM8731_VERSION "0.12"
+
+/*
+ * Debug
+ */
+
+#define WM8731_DEBUG 0
+
+#ifdef WM8731_DEBUG
+#define dbg(format, arg...) \
+	printk(KERN_DEBUG AUDIO_NAME ": " format "\n" , ## arg)
+#else
+#define dbg(format, arg...) do {} while (0)
+#endif
+#define err(format, arg...) \
+	printk(KERN_ERR AUDIO_NAME ": " format "\n" , ## arg)
+#define info(format, arg...) \
+	printk(KERN_INFO AUDIO_NAME ": " format "\n" , ## arg)
+#define warn(format, arg...) \
+	printk(KERN_WARNING AUDIO_NAME ": " format "\n" , ## arg)
+
+struct snd_soc_codec_device soc_codec_dev_wm8731;
+
+/*
+ * wm8731 register cache
+ * We can't read the WM8731 register space when we are
+ * using 2 wire for device control, so we cache them instead.
+ * There is no point in caching the reset register
+ */
+static const u16 wm8731_reg[WM8731_CACHEREGNUM] = {
+    0x0097, 0x0097, 0x0079, 0x0079,
+    0x000a, 0x0008, 0x009f, 0x000a,
+    0x0000, 0x0000
+};
+
+#define WM8731_DAIFMT \
+	(SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_LEFT_J | SND_SOC_DAIFMT_RIGHT_J | \
+	SND_SOC_DAIFMT_NB_NF | SND_SOC_DAIFMT_NB_IF | SND_SOC_DAIFMT_IB_NF | \
+	SND_SOC_DAIFMT_IB_IF)
+
+#define WM8731_DIR \
+	(SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE)
+
+#define WM8731_RATES \
+	(SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 | SNDRV_PCM_RATE_16000 | \
+	SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | \
+	SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000)
+
+#define WM8731_HIFI_BITS \
+	(SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE | \
+	SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)
+
+static struct snd_soc_dai_mode wm8731_modes[] = {
+	/* codec frame and clock master modes */
+	/* 8k */
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_8000, WM8731_DIR, 0,
+		1536, SND_SOC_FSB(64)},
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_8000, WM8731_DIR, 0,
+		2304, SND_SOC_FSB(64)},
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_8000, WM8731_DIR, 0,
+		1408, SND_SOC_FSB(64)},
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_8000, WM8731_DIR, 0,
+		2112, SND_SOC_FSB(64)},
+
+	/* 32k */
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_32000, WM8731_DIR, 0,
+		384, SND_SOC_FSB(64)},
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_32000, WM8731_DIR, 0,
+		576, SND_SOC_FSB(64)},
+
+	/* 44.1k & 48k */
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
+		WM8731_DIR, 0, 256, SND_SOC_FSB(64)},
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
+		WM8731_DIR, 0, 384, SND_SOC_FSB(64)},
+
+	/* 88.2 & 96k */
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000,
+		WM8731_DIR, 0, 128, SND_SOC_FSB(64)},
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000,
+		WM8731_DIR, 0, 192, SND_SOC_FSB(64)},
+
+
+	/* USB codec frame and clock master modes */
+	/* 8k */
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_8000, WM8731_DIR,
+		SND_SOC_DAI_BFS_DIV, 1500, SND_SOC_FSBD(1)},
+
+	/* 44.1k */
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_44100, WM8731_DIR,
+		SND_SOC_DAI_BFS_DIV, 272, SND_SOC_FSBD(1)},
+
+	/* 48k */
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_48000, WM8731_DIR,
+		SND_SOC_DAI_BFS_DIV, 250, SND_SOC_FSBD(1)},
+
+	/* 88.2k */
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_88200, WM8731_DIR,
+		SND_SOC_DAI_BFS_DIV, 136, SND_SOC_FSBD(1)},
+
+	/* 96k */
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, SNDRV_PCM_RATE_96000, WM8731_DIR,
+		SND_SOC_DAI_BFS_DIV, 125, SND_SOC_FSBD(1)},
+
+	/* codec frame and clock slave modes */
+	{WM8731_DAIFMT | SND_SOC_DAIFMT_CBS_CFS, SND_SOC_DAITDM_LRDW(0,0),
+		WM8731_HIFI_BITS, WM8731_RATES, WM8731_DIR, SND_SOC_DAI_BFS_DIV,
+		SND_SOC_FS_ALL, SND_SOC_FSBD_ALL},
+};
+
+/*
+ * read wm8731 register cache
+ */
+static inline unsigned int wm8731_read_reg_cache(struct snd_soc_codec *codec,
+	unsigned int reg)
+{
+	u16 *cache = codec->reg_cache;
+	if (reg == WM8731_RESET)
+		return 0;
+	if (reg >= WM8731_CACHEREGNUM)
+		return -1;
+	return cache[reg];
+}
+
+/*
+ * write wm8731 register cache
+ */
+static inline void wm8731_write_reg_cache(struct snd_soc_codec *codec,
+	u16 reg, unsigned int value)
+{
+	u16 *cache = codec->reg_cache;
+	if (reg >= WM8731_CACHEREGNUM)
+		return;
+	cache[reg] = value;
+}
+
+/*
+ * write to the WM8731 register space
+ */
+static int wm8731_write(struct snd_soc_codec *codec, unsigned int reg,
+	unsigned int value)
+{
+	u8 data[2];
+
+	/* data is
+	 *   D15..D9 WM8731 register offset
+	 *   D8...D0 register data
+	 */
+	data[0] = (reg << 1) | ((value >> 8) & 0x0001);
+	data[1] = value & 0x00ff;
+
+	wm8731_write_reg_cache (codec, reg, value);
+	if (codec->hw_write(codec->control_data, data, 2) == 2)
+		return 0;
+	else
+		return -EIO;
+}
+
+#define wm8731_reset(c)	wm8731_write(c, WM8731_RESET, 0)
+
+static const char *wm8731_input_select[] = {"Line In", "Mic"};
+static const char *wm8731_deemph[] = {"None", "32Khz", "44.1Khz", "48Khz"};
+
+static const struct soc_enum wm8731_enum[] = {
+	SOC_ENUM_SINGLE(WM8731_APANA, 2, 2, wm8731_input_select),
+	SOC_ENUM_SINGLE(WM8731_APDIGI, 1, 4, wm8731_deemph),
+};
+
+static const struct snd_kcontrol_new wm8731_snd_controls[] = {
+
+SOC_DOUBLE_R("Playback Volume", WM8731_LOUT1V, WM8731_ROUT1V, 0, 127, 0),
+SOC_DOUBLE_R("Playback ZC Switch", WM8731_LOUT1V, WM8731_ROUT1V, 7, 1, 0),
+
+SOC_DOUBLE_R("Capture Volume", WM8731_LINVOL, WM8731_RINVOL, 0, 31, 0),
+SOC_DOUBLE_R("Line Capture Switch", WM8731_LINVOL, WM8731_RINVOL, 7, 1, 1),
+
+SOC_SINGLE("Mic Boost (+20dB)", WM8731_APANA, 0, 1, 0),
+SOC_SINGLE("Capture Mic Switch", WM8731_APANA, 1, 1, 1),
+
+SOC_SINGLE("Sidetone Playback Volume", WM8731_APANA, 6, 3, 1),
+
+SOC_SINGLE("ADC High Pass Filter Switch", WM8731_APDIGI, 0, 1, 1),
+SOC_SINGLE("Store DC Offset Switch", WM8731_APDIGI, 4, 1, 0),
+
+SOC_ENUM("Playback De-emphasis", wm8731_enum[1]),
+};
+
+/* add non dapm controls */
+static int wm8731_add_controls(struct snd_soc_codec *codec)
+{
+	int err, i;
+
+	for (i = 0; i < ARRAY_SIZE(wm8731_snd_controls); i++) {
+		if ((err = snd_ctl_add(codec->card,
+				snd_soc_cnew(&wm8731_snd_controls[i],codec, NULL))) < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+/* Output Mixer */
+static const struct snd_kcontrol_new wm8731_output_mixer_controls[] = {
+SOC_DAPM_SINGLE("Line Bypass Switch", WM8731_APANA, 3, 1, 0),
+SOC_DAPM_SINGLE("Mic Sidetone Switch", WM8731_APANA, 5, 1, 0),
+SOC_DAPM_SINGLE("HiFi Playback Switch", WM8731_APANA, 4, 1, 0),
+};
+
+/* Input mux */
+static const struct snd_kcontrol_new wm8731_input_mux_controls =
+SOC_DAPM_ENUM("Input Select", wm8731_enum[0]);
+
+static const struct snd_soc_dapm_widget wm8731_dapm_widgets[] = {
+SND_SOC_DAPM_MIXER("Output Mixer", WM8731_PWR, 4, 1,
+	&wm8731_output_mixer_controls[0],
+	ARRAY_SIZE(wm8731_output_mixer_controls)),
+SND_SOC_DAPM_DAC("DAC", "HiFi Playback", WM8731_PWR, 3, 1),
+SND_SOC_DAPM_OUTPUT("LOUT"),
+SND_SOC_DAPM_OUTPUT("LHPOUT"),
+SND_SOC_DAPM_OUTPUT("ROUT"),
+SND_SOC_DAPM_OUTPUT("RHPOUT"),
+SND_SOC_DAPM_ADC("ADC", "HiFi Capture", WM8731_PWR, 2, 1),
+SND_SOC_DAPM_MUX("Input Mux", SND_SOC_NOPM, 0, 0, &wm8731_input_mux_controls),
+SND_SOC_DAPM_PGA("Line Input", WM8731_PWR, 0, 1, NULL, 0),
+SND_SOC_DAPM_MICBIAS("Mic Bias", WM8731_PWR, 1, 1),
+SND_SOC_DAPM_INPUT("MICIN"),
+SND_SOC_DAPM_INPUT("RLINEIN"),
+SND_SOC_DAPM_INPUT("LLINEIN"),
+};
+
+static const char *intercon[][3] = {
+	/* output mixer */
+	{"Output Mixer", "Line Bypass Switch", "Line Input"},
+	{"Output Mixer", "HiFi Playback Switch", "DAC"},
+	{"Output Mixer", "Mic Sidetone Switch", "Mic Bias"},
+
+	/* outputs */
+	{"RHPOUT", NULL, "Output Mixer"},
+	{"ROUT", NULL, "Output Mixer"},
+	{"LHPOUT", NULL, "Output Mixer"},
+	{"LOUT", NULL, "Output Mixer"},
+
+	/* input mux */
+	{"Input Mux", "Line In", "Line Input"},
+	{"Input Mux", "Mic", "Mic Bias"},
+	{"ADC", NULL, "Input Mux"},
+
+	/* inputs */
+	{"Line Input", NULL, "LLINEIN"},
+	{"Line Input", NULL, "RLINEIN"},
+	{"Mic Bias", NULL, "MICIN"},
+
+	/* terminator */
+	{NULL, NULL, NULL},
+};
+
+static int wm8731_add_widgets(struct snd_soc_codec *codec)
+{
+	int i;
+
+	for(i = 0; i < ARRAY_SIZE(wm8731_dapm_widgets); i++) {
+		snd_soc_dapm_new_control(codec, &wm8731_dapm_widgets[i]);
+	}
+
+	/* set up audio path interconnects */
+	for(i = 0; intercon[i][0] != NULL; i++) {
+		snd_soc_dapm_connect_input(codec, intercon[i][0],
+			intercon[i][1], intercon[i][2]);
+	}
+
+	snd_soc_dapm_new_widgets(codec);
+	return 0;
+}
+
+struct _coeff_div {
+	u32 mclk;
+	u32 rate;
+	u16 fs;
+	u8 sr:4;
+	u8 bosr:1;
+	u8 usb:1;
+};
+
+/* codec mclk clock divider coefficients */
+static const struct _coeff_div coeff_div[] = {
+	/* 48k */
+	{12288000, 48000, 256, 0x0, 0x0, 0x0},
+	{18432000, 48000, 384, 0x0, 0x1, 0x0},
+	{12000000, 48000, 250, 0x0, 0x0, 0x1},
+
+	/* 32k */
+	{12288000, 32000, 384, 0x6, 0x0, 0x0},
+	{18432000, 32000, 576, 0x6, 0x1, 0x0},
+
+	/* 8k */
+	{12288000, 8000, 1536, 0x3, 0x0, 0x0},
+	{18432000, 8000, 2304, 0x3, 0x1, 0x0},
+	{11289600, 8000, 1408, 0xb, 0x0, 0x0},
+	{16934400, 8000, 2112, 0xb, 0x1, 0x0},
+	{12000000, 8000, 1500, 0x3, 0x0, 0x1},
+
+	/* 96k */
+	{12288000, 96000, 128, 0x7, 0x0, 0x0},
+	{18432000, 96000, 192, 0x7, 0x1, 0x0},
+	{12000000, 96000, 125, 0x7, 0x0, 0x1},
+
+	/* 44.1k */
+	{11289600, 44100, 256, 0x8, 0x0, 0x0},
+	{16934400, 44100, 384, 0x8, 0x1, 0x0},
+	{12000000, 44100, 272, 0x8, 0x1, 0x1},
+
+	/* 88.2k */
+	{11289600, 88200, 128, 0xf, 0x0, 0x0},
+	{16934400, 88200, 192, 0xf, 0x1, 0x0},
+	{12000000, 88200, 136, 0xf, 0x1, 0x1},
+};
+
+static inline int get_coeff(int mclk, int rate)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(coeff_div); i++) {
+		if (coeff_div[i].rate == rate && coeff_div[i].mclk == mclk)
+			return i;
+	}
+	return 0;
+}
+
+/* WM8731 supports numerous clocks per sample rate */
+static unsigned int wm8731_config_sysclk(struct snd_soc_codec_dai *dai,
+	struct snd_soc_clock_info *info, unsigned int clk)
+{
+	dai->mclk = 0;
+
+	/* check that the calculated FS and rate actually match a clock from
+	 * the machine driver */
+	if (info->fs * info->rate == clk)
+		dai->mclk = clk;
+
+	return dai->mclk;
+}
+
+static int wm8731_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_device *socdev = rtd->socdev;
+	struct snd_soc_codec *codec = socdev->codec;
+	u16 iface = 0, srate;
+	int i = get_coeff(rtd->codec_dai->mclk,
+		snd_soc_get_rate(rtd->codec_dai->dai_runtime.pcmrate));
+
+	/* set master/slave audio interface */
+	switch (rtd->codec_dai->dai_runtime.fmt & SND_SOC_DAIFMT_CLOCK_MASK) {
+	case SND_SOC_DAIFMT_CBM_CFM:
+		iface |= 0x0040;
+		break;
+	case SND_SOC_DAIFMT_CBS_CFS:
+		break;
+	}
+	srate = (coeff_div[i].sr << 2) |
+		(coeff_div[i].bosr << 1) | coeff_div[i].usb;
+	wm8731_write(codec, WM8731_SRATE, srate);
+
+	/* interface format */
+	switch (rtd->codec_dai->dai_runtime.fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		iface |= 0x0002;
+		break;
+	case SND_SOC_DAIFMT_RIGHT_J:
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		iface |= 0x0001;
+		break;
+	case SND_SOC_DAIFMT_DSP_A:
+		iface |= 0x0003;
+		break;
+	case SND_SOC_DAIFMT_DSP_B:
+		iface |= 0x0013;
+		break;
+	}
+
+	/* bit size */
+	switch (rtd->codec_dai->dai_runtime.pcmfmt) {
+	case SNDRV_PCM_FMTBIT_S16_LE:
+		break;
+	case SNDRV_PCM_FMTBIT_S20_3LE:
+		iface |= 0x0004;
+		break;
+	case SNDRV_PCM_FMTBIT_S24_LE:
+		iface |= 0x0008;
+		break;
+	case SNDRV_PCM_FMTBIT_S32_LE:
+		iface |= 0x000c;
+		break;
+	}
+
+	/* clock inversion */
+	switch (rtd->codec_dai->dai_runtime.fmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_NB_NF:
+		break;
+	case SND_SOC_DAIFMT_IB_IF:
+		iface |= 0x0090;
+		break;
+	case SND_SOC_DAIFMT_IB_NF:
+		iface |= 0x0080;
+		break;
+	case SND_SOC_DAIFMT_NB_IF:
+		iface |= 0x0010;
+		break;
+	}
+
+	/* set iface */
+	wm8731_write(codec, WM8731_IFACE, iface);
+
+	/* set active */
+	wm8731_write(codec, WM8731_ACTIVE, 0x0001);
+	return 0;
+}
+
+static void wm8731_shutdown(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_device *socdev = rtd->socdev;
+	struct snd_soc_codec *codec = socdev->codec;
+
+	/* deactivate */
+	if (!codec->active) {
+		udelay(50);
+		wm8731_write(codec, WM8731_ACTIVE, 0x0);
+	}
+}
+
+static int wm8731_mute(struct snd_soc_codec *codec,
+	struct snd_soc_codec_dai *dai, int mute)
+{
+	u16 mute_reg = wm8731_read_reg_cache(codec, WM8731_APDIGI) & 0xfff7;
+	if (mute)
+		wm8731_write(codec, WM8731_APDIGI, mute_reg | 0x8);
+	else
+		wm8731_write(codec, WM8731_APDIGI, mute_reg);
+	return 0;
+}
+
+static int wm8731_dapm_event(struct snd_soc_codec *codec, int event)
+{
+	u16 reg = wm8731_read_reg_cache(codec, WM8731_PWR) & 0xff7f;
+
+	switch (event) {
+	case SNDRV_CTL_POWER_D0: /* full On */
+		/* vref/mid, osc on, dac unmute */
+		wm8731_write(codec, WM8731_PWR, reg);
+		break;
+	case SNDRV_CTL_POWER_D1: /* partial On */
+	case SNDRV_CTL_POWER_D2: /* partial On */
+		break;
+	case SNDRV_CTL_POWER_D3hot: /* Off, with power */
+		/* everything off except vref/vmid, */
+		wm8731_write(codec, WM8731_PWR, reg | 0x0040);
+		break;
+	case SNDRV_CTL_POWER_D3cold: /* Off, without power */
+		/* everything off, dac mute, inactive */
+		wm8731_write(codec, WM8731_ACTIVE, 0x0);
+		wm8731_write(codec, WM8731_PWR, 0xffff);
+		break;
+	}
+	codec->dapm_state = event;
+	return 0;
+}
+
+struct snd_soc_codec_dai wm8731_dai = {
+	.name = "WM8731",
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 1,
+		.channels_max = 2,
+	},
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 1,
+		.channels_max = 2,
+	},
+	.config_sysclk = wm8731_config_sysclk,
+	.digital_mute = wm8731_mute,
+	.ops = {
+		.prepare = wm8731_pcm_prepare,
+		.shutdown = wm8731_shutdown,
+	},
+	.caps = {
+		.num_modes = ARRAY_SIZE(wm8731_modes),
+		.mode = wm8731_modes,
+	},
+};
+EXPORT_SYMBOL_GPL(wm8731_dai);
+
+static int wm8731_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+	struct snd_soc_codec *codec = socdev->codec;
+
+	wm8731_write(codec, WM8731_ACTIVE, 0x0);
+	wm8731_dapm_event(codec, SNDRV_CTL_POWER_D3cold);
+	return 0;
+}
+
+static int wm8731_resume(struct platform_device *pdev)
+{
+	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+	struct snd_soc_codec *codec = socdev->codec;
+	int i;
+	u8 data[2];
+	u16 *cache = codec->reg_cache;
+
+	/* Sync reg_cache with the hardware */
+	for (i = 0; i < ARRAY_SIZE(wm8731_reg); i++) {
+		data[0] = (i << 1) | ((cache[i] >> 8) & 0x0001);
+		data[1] = cache[i] & 0x00ff;
+		codec->hw_write(codec->control_data, data, 2);
+	}
+	wm8731_dapm_event(codec, SNDRV_CTL_POWER_D3hot);
+	wm8731_dapm_event(codec, codec->suspend_dapm_state);
+	return 0;
+}
+
+/*
+ * initialise the WM8731 driver
+ * register the mixer and dsp interfaces with the kernel
+ */
+static int wm8731_init(struct snd_soc_device *socdev)
+{
+	struct snd_soc_codec *codec = socdev->codec;
+	int reg, ret = 0;
+
+	codec->name = "WM8731";
+	codec->owner = THIS_MODULE;
+	codec->read = wm8731_read_reg_cache;
+	codec->write = wm8731_write;
+	codec->dapm_event = wm8731_dapm_event;
+	codec->dai = &wm8731_dai;
+	codec->num_dai = 1;
+	codec->reg_cache_size = ARRAY_SIZE(wm8731_reg);
+
+	codec->reg_cache =
+			kzalloc(sizeof(u16) * ARRAY_SIZE(wm8731_reg), GFP_KERNEL);
+	if (codec->reg_cache == NULL)
+		return -ENOMEM;
+	memcpy(codec->reg_cache,
+		wm8731_reg, sizeof(u16) * ARRAY_SIZE(wm8731_reg));
+	codec->reg_cache_size = sizeof(u16) * ARRAY_SIZE(wm8731_reg);
+
+	wm8731_reset(codec);
+
+	/* register pcms */
+	ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
+	if (ret < 0) {
+		kfree(codec->reg_cache);
+		return ret;
+	}
+
+	/* power on device */
+	wm8731_dapm_event(codec, SNDRV_CTL_POWER_D3hot);
+
+	/* set the update bits */
+	reg = wm8731_read_reg_cache(codec, WM8731_LOUT1V);
+	wm8731_write(codec, WM8731_LOUT1V, reg | 0x0100);
+	reg = wm8731_read_reg_cache(codec, WM8731_ROUT1V);
+	wm8731_write(codec, WM8731_ROUT1V, reg | 0x0100);
+	reg = wm8731_read_reg_cache(codec, WM8731_LINVOL);
+	wm8731_write(codec, WM8731_LINVOL, reg | 0x0100);
+	reg = wm8731_read_reg_cache(codec, WM8731_RINVOL);
+	wm8731_write(codec, WM8731_RINVOL, reg | 0x0100);
+
+	wm8731_add_controls(codec);
+	wm8731_add_widgets(codec);
+	ret = snd_soc_register_card(socdev);
+	if (ret < 0) {
+		snd_soc_free_pcms(socdev);
+		snd_soc_dapm_free(socdev);
+	}
+
+	return ret;
+}
+
+static struct snd_soc_device *wm8731_socdev;
+
+#if defined (CONFIG_I2C) || defined (CONFIG_I2C_MODULE)
+
+/*
+ * WM8731 2 wire address is determined by GPIO5
+ * state during powerup.
+ *    low  = 0x1a
+ *    high = 0x1b
+ */
+static unsigned short normal_i2c[] = { 0, I2C_CLIENT_END };
+
+/* Magic definition of all other variables and things */
+I2C_CLIENT_INSMOD;
+
+static struct i2c_driver wm8731_i2c_driver;
+static struct i2c_client client_template;
+
+/* If the i2c layer weren't so broken, we could pass this kind of data
+   around */
+
+static int wm8731_codec_probe(struct i2c_adapter *adap, int addr, int kind)
+{
+	struct snd_soc_device *socdev = wm8731_socdev;
+	struct wm8731_setup_data *setup = socdev->codec_data;
+	struct snd_soc_codec *codec = socdev->codec;
+	struct i2c_client *i2c;
+	int ret;
+
+	if (addr != setup->i2c_address)
+		return -ENODEV;
+
+	client_template.adapter = adap;
+	client_template.addr = addr;
+
+	i2c = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
+	if (i2c == NULL) {
+		kfree(codec);
+		return -ENOMEM;
+	}
+	memcpy(i2c, &client_template, sizeof(struct i2c_client));
+	i2c_set_clientdata(i2c, codec);
+	codec->control_data = i2c;
+
+	ret = i2c_attach_client(i2c);
+	if (ret < 0) {
+		err("failed to attach codec at addr %x\n", addr);
+		goto err;
+	}
+
+	ret = wm8731_init(socdev);
+	if (ret < 0) {
+		err("failed to initialise WM8731\n");
+		goto err;
+	}
+	return ret;
+
+err:
+	kfree(codec);
+	kfree(i2c);
+	return ret;
+}
+
+static int wm8731_i2c_detach(struct i2c_client *client)
+{
+	struct snd_soc_codec* codec = i2c_get_clientdata(client);
+	i2c_detach_client(client);
+	kfree(codec->reg_cache);
+	kfree(client);
+	return 0;
+}
+
+static int wm8731_i2c_attach(struct i2c_adapter *adap)
+{
+	return i2c_probe(adap, &addr_data, wm8731_codec_probe);
+}
+
+/* corgi i2c codec control layer */
+static struct i2c_driver wm8731_i2c_driver = {
+	.driver = {
+		.name = "WM8731 I2C Codec",
+		.owner = THIS_MODULE,
+	},
+	.id =             I2C_DRIVERID_WM8731,
+	.attach_adapter = wm8731_i2c_attach,
+	.detach_client =  wm8731_i2c_detach,
+	.command =        NULL,
+};
+
+static struct i2c_client client_template = {
+	.name =   "WM8731",
+	.driver = &wm8731_i2c_driver,
+};
+#endif
+
+static int wm8731_probe(struct platform_device *pdev)
+{
+	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+	struct wm8731_setup_data *setup;
+	struct snd_soc_codec *codec;
+	int ret = 0;
+
+	info("WM8731 Audio Codec %s", WM8731_VERSION);
+
+	setup = socdev->codec_data;
+	codec = kzalloc(sizeof(struct snd_soc_codec), GFP_KERNEL);
+	if (codec == NULL)
+		return -ENOMEM;
+
+	socdev->codec = codec;
+	mutex_init(&codec->mutex);
+	INIT_LIST_HEAD(&codec->dapm_widgets);
+	INIT_LIST_HEAD(&codec->dapm_paths);
+
+	wm8731_socdev = socdev;
+#if defined (CONFIG_I2C) || defined (CONFIG_I2C_MODULE)
+	if (setup->i2c_address) {
+		normal_i2c[0] = setup->i2c_address;
+		codec->hw_write = (hw_write_t)i2c_master_send;
+		ret = i2c_add_driver(&wm8731_i2c_driver);
+		if (ret != 0)
+			printk(KERN_ERR "can't add i2c driver");
+	}
+#else
+	/* Add other interfaces here */
+#endif
+	return ret;
+}
+
+/* power down chip */
+static int wm8731_remove(struct platform_device *pdev)
+{
+	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+	struct snd_soc_codec *codec = socdev->codec;
+
+	if (codec->control_data)
+		wm8731_dapm_event(codec, SNDRV_CTL_POWER_D3cold);
+
+	snd_soc_free_pcms(socdev);
+	snd_soc_dapm_free(socdev);
+#if defined (CONFIG_I2C) || defined (CONFIG_I2C_MODULE)
+	i2c_del_driver(&wm8731_i2c_driver);
+#endif
+	kfree(codec);
+
+	return 0;
+}
+
+struct snd_soc_codec_device soc_codec_dev_wm8731 = {
+	.probe = 	wm8731_probe,
+	.remove = 	wm8731_remove,
+	.suspend = 	wm8731_suspend,
+	.resume =	wm8731_resume,
+};
+
+EXPORT_SYMBOL_GPL(soc_codec_dev_wm8731);
+
+MODULE_DESCRIPTION("ASoC WM8731 driver");
+MODULE_AUTHOR("Richard Purdie");
+MODULE_LICENSE("GPL");
diff --git a/sound/soc/codecs/wm8731.h b/sound/soc/codecs/wm8731.h
new file mode 100644
index 000000000000..8fa0f53bef1c
--- /dev/null
+++ b/sound/soc/codecs/wm8731.h
@@ -0,0 +1,41 @@
+/*
+ * wm8731.h  --  WM8731 Soc Audio driver
+ *
+ * Copyright 2005 Openedhand Ltd.
+ *
+ * Author: Richard Purdie <richard@openedhand.com>
+ *
+ * Based on wm8753.h
+ *
+ * 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.
+ */
+
+#ifndef _WM8731_H
+#define _WM8731_H
+
+/* WM8731 register space */
+
+#define WM8731_LINVOL   0x00
+#define WM8731_RINVOL   0x01
+#define WM8731_LOUT1V   0x02
+#define WM8731_ROUT1V   0x03
+#define WM8731_APANA    0x04
+#define WM8731_APDIGI   0x05
+#define WM8731_PWR      0x06
+#define WM8731_IFACE    0x07
+#define WM8731_SRATE    0x08
+#define WM8731_ACTIVE   0x09
+#define WM8731_RESET	0x0f
+
+#define WM8731_CACHEREGNUM 	10
+
+struct wm8731_setup_data {
+	unsigned short i2c_address;
+};
+
+extern struct snd_soc_codec_dai wm8731_dai;
+extern struct snd_soc_codec_device soc_codec_dev_wm8731;
+
+#endif