ALSA: ASoC: Add AK4535 driver

The AK4535 codec is included in some HP iPAQ systems.

This driver was originally written by Richard Purdie and with some bug
fixes from Milan Plzik.  While out of tree it has also had some
mechanical updates for new APIs and current best practices from Liam
Girdwood, Graeme Gregory and Mark Brown.
Signed-off-by: Richard Purdie <richard@openedhand.com>
Signed-off-by: Milan Plzik <milan.plzik@gmail.com>
Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Graeme Gregory <gg@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/soc/codecs/Kconfig

@@ -2,6 +2,9 @@ config SND_SOC_AC97_CODEC
 	tristate
 	select SND_AC97_CODEC
 
+config SND_SOC_AK4535
+	tristate
+
 config SND_SOC_UDA1380
         tristate
 

sound/soc/codecs/Makefile

 snd-soc-ac97-objs := ac97.o
+snd-soc-ak4535-objs := ak4535.o
 snd-soc-uda1380-objs := uda1380.o
 snd-soc-wm8510-objs := wm8510.o
 snd-soc-wm8731-objs := wm8731.o
@@ -11,6 +12,7 @@ snd-soc-cs4270-objs := cs4270.o
 snd-soc-tlv320aic3x-objs := tlv320aic3x.o
 
 obj-$(CONFIG_SND_SOC_AC97_CODEC)	+= snd-soc-ac97.o
+obj-$(CONFIG_SND_SOC_AK4535)	+= snd-soc-ak4535.o
 obj-$(CONFIG_SND_SOC_UDA1380)	+= snd-soc-uda1380.o
 obj-$(CONFIG_SND_SOC_WM8510)	+= snd-soc-wm8510.o
 obj-$(CONFIG_SND_SOC_WM8731)	+= snd-soc-wm8731.o

sound/soc/codecs/ak4535.c

+/*
+ * ak4535.c  --  AK4535 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/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 "ak4535.h"
+
+#define AUDIO_NAME "ak4535"
+#define AK4535_VERSION "0.3"
+
+struct snd_soc_codec_device soc_codec_dev_ak4535;
+
+/* codec private data */
+struct ak4535_priv {
+	unsigned int sysclk;
+};
+
+/*
+ * ak4535 register cache
+ */
+static const u16 ak4535_reg[AK4535_CACHEREGNUM] = {
+    0x0000, 0x0080, 0x0000, 0x0003,
+    0x0002, 0x0000, 0x0011, 0x0001,
+    0x0000, 0x0040, 0x0036, 0x0010,
+    0x0000, 0x0000, 0x0057, 0x0000,
+};
+
+/*
+ * read ak4535 register cache
+ */
+static inline unsigned int ak4535_read_reg_cache(struct snd_soc_codec *codec,
+	unsigned int reg)
+{
+	u16 *cache = codec->reg_cache;
+	if (reg >= AK4535_CACHEREGNUM)
+		return -1;
+	return cache[reg];
+}
+
+static inline unsigned int ak4535_read(struct snd_soc_codec *codec,
+	unsigned int reg)
+{
+	u8 data;
+	data = reg;
+
+	if (codec->hw_write(codec->control_data, &data, 1) != 1)
+		return -EIO;
+
+	if (codec->hw_read(codec->control_data, &data, 1) != 1)
+		return -EIO;
+
+	return data;
+};
+
+/*
+ * write ak4535 register cache
+ */
+static inline void ak4535_write_reg_cache(struct snd_soc_codec *codec,
+	u16 reg, unsigned int value)
+{
+	u16 *cache = codec->reg_cache;
+	if (reg >= AK4535_CACHEREGNUM)
+		return;
+	cache[reg] = value;
+}
+
+/*
+ * write to the AK4535 register space
+ */
+static int ak4535_write(struct snd_soc_codec *codec, unsigned int reg,
+	unsigned int value)
+{
+	u8 data[2];
+
+	/* data is
+	 *   D15..D8 AK4535 register offset
+	 *   D7...D0 register data
+	 */
+	data[0] = reg & 0xff;
+	data[1] = value & 0xff;
+
+	ak4535_write_reg_cache(codec, reg, value);
+	if (codec->hw_write(codec->control_data, data, 2) == 2)
+		return 0;
+	else
+		return -EIO;
+}
+
+static int ak4535_sync(struct snd_soc_codec *codec)
+{
+	u16 *cache = codec->reg_cache;
+	int i, r = 0;
+
+	for (i = 0; i < AK4535_CACHEREGNUM; i++)
+		r |= ak4535_write(codec, i, cache[i]);
+
+	return r;
+};
+
+static const char *ak4535_mono_gain[] = {"+6dB", "-17dB"};
+static const char *ak4535_mono_out[] = {"(L + R)/2", "Hi-Z"};
+static const char *ak4535_hp_out[] = {"Stereo", "Mono"};
+static const char *ak4535_deemp[] = {"44.1kHz", "Off", "48kHz", "32kHz"};
+static const char *ak4535_mic_select[] = {"Internal", "External"};
+
+static const struct soc_enum ak4535_enum[] = {
+	SOC_ENUM_SINGLE(AK4535_SIG1, 7, 2, ak4535_mono_gain),
+	SOC_ENUM_SINGLE(AK4535_SIG1, 6, 2, ak4535_mono_out),
+	SOC_ENUM_SINGLE(AK4535_MODE2, 2, 2, ak4535_hp_out),
+	SOC_ENUM_SINGLE(AK4535_DAC, 0, 4, ak4535_deemp),
+	SOC_ENUM_SINGLE(AK4535_MIC, 1, 2, ak4535_mic_select),
+};
+
+static const struct snd_kcontrol_new ak4535_snd_controls[] = {
+	SOC_SINGLE("ALC2 Switch", AK4535_SIG1, 1, 1, 0),
+	SOC_ENUM("Mono 1 Output", ak4535_enum[1]),
+	SOC_ENUM("Mono 1 Gain", ak4535_enum[0]),
+	SOC_ENUM("Headphone Output", ak4535_enum[2]),
+	SOC_ENUM("Playback Deemphasis", ak4535_enum[3]),
+	SOC_SINGLE("Bass Volume", AK4535_DAC, 2, 3, 0),
+	SOC_SINGLE("Mic Boost (+20dB) Switch", AK4535_MIC, 0, 1, 0),
+	SOC_ENUM("Mic Select", ak4535_enum[4]),
+	SOC_SINGLE("ALC Operation Time", AK4535_TIMER, 0, 3, 0),
+	SOC_SINGLE("ALC Recovery Time", AK4535_TIMER, 2, 3, 0),
+	SOC_SINGLE("ALC ZC Time", AK4535_TIMER, 4, 3, 0),
+	SOC_SINGLE("ALC 1 Switch", AK4535_ALC1, 5, 1, 0),
+	SOC_SINGLE("ALC 2 Switch", AK4535_ALC1, 6, 1, 0),
+	SOC_SINGLE("ALC Volume", AK4535_ALC2, 0, 127, 0),
+	SOC_SINGLE("Capture Volume", AK4535_PGA, 0, 127, 0),
+	SOC_SINGLE("Left Playback Volume", AK4535_LATT, 0, 127, 1),
+	SOC_SINGLE("Right Playback Volume", AK4535_RATT, 0, 127, 1),
+	SOC_SINGLE("AUX Bypass Volume", AK4535_VOL, 0, 15, 0),
+	SOC_SINGLE("Mic Sidetone Volume", AK4535_VOL, 4, 7, 0),
+};
+
+/* add non dapm controls */
+static int ak4535_add_controls(struct snd_soc_codec *codec)
+{
+	int err, i;
+
+	for (i = 0; i < ARRAY_SIZE(ak4535_snd_controls); i++) {
+		err = snd_ctl_add(codec->card,
+			snd_soc_cnew(&ak4535_snd_controls[i], codec, NULL));
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+/* Mono 1 Mixer */
+static const struct snd_kcontrol_new ak4535_mono1_mixer_controls[] = {
+	SOC_DAPM_SINGLE("Mic Sidetone Switch", AK4535_SIG1, 4, 1, 0),
+	SOC_DAPM_SINGLE("Mono Playback Switch", AK4535_SIG1, 5, 1, 0),
+};
+
+/* Stereo Mixer */
+static const struct snd_kcontrol_new ak4535_stereo_mixer_controls[] = {
+	SOC_DAPM_SINGLE("Mic Sidetone Switch", AK4535_SIG2, 4, 1, 0),
+	SOC_DAPM_SINGLE("Playback Switch", AK4535_SIG2, 7, 1, 0),
+	SOC_DAPM_SINGLE("Aux Bypass Switch", AK4535_SIG2, 5, 1, 0),
+};
+
+/* Input Mixer */
+static const struct snd_kcontrol_new ak4535_input_mixer_controls[] = {
+	SOC_DAPM_SINGLE("Mic Capture Switch", AK4535_MIC, 2, 1, 0),
+	SOC_DAPM_SINGLE("Aux Capture Switch", AK4535_MIC, 5, 1, 0),
+};
+
+/* Input mux */
+static const struct snd_kcontrol_new ak4535_input_mux_control =
+	SOC_DAPM_ENUM("Input Select", ak4535_enum[4]);
+
+/* HP L switch */
+static const struct snd_kcontrol_new ak4535_hpl_control =
+	SOC_DAPM_SINGLE("Switch", AK4535_SIG2, 1, 1, 1);
+
+/* HP R switch */
+static const struct snd_kcontrol_new ak4535_hpr_control =
+	SOC_DAPM_SINGLE("Switch", AK4535_SIG2, 0, 1, 1);
+
+/* mono 2 switch */
+static const struct snd_kcontrol_new ak4535_mono2_control =
+	SOC_DAPM_SINGLE("Switch", AK4535_SIG1, 0, 1, 0);
+
+/* Line out switch */
+static const struct snd_kcontrol_new ak4535_line_control =
+	SOC_DAPM_SINGLE("Switch", AK4535_SIG2, 6, 1, 0);
+
+/* ak4535 dapm widgets */
+static const struct snd_soc_dapm_widget ak4535_dapm_widgets[] = {
+	SND_SOC_DAPM_MIXER("Stereo Mixer", SND_SOC_NOPM, 0, 0,
+		&ak4535_stereo_mixer_controls[0],
+		ARRAY_SIZE(ak4535_stereo_mixer_controls)),
+	SND_SOC_DAPM_MIXER("Mono1 Mixer", SND_SOC_NOPM, 0, 0,
+		&ak4535_mono1_mixer_controls[0],
+		ARRAY_SIZE(ak4535_mono1_mixer_controls)),
+	SND_SOC_DAPM_MIXER("Input Mixer", SND_SOC_NOPM, 0, 0,
+		&ak4535_input_mixer_controls[0],
+		ARRAY_SIZE(ak4535_input_mixer_controls)),
+	SND_SOC_DAPM_MUX("Input Mux", SND_SOC_NOPM, 0, 0,
+		&ak4535_input_mux_control),
+	SND_SOC_DAPM_DAC("DAC", "Playback", AK4535_PM2, 0, 0),
+	SND_SOC_DAPM_SWITCH("Mono 2 Enable", SND_SOC_NOPM, 0, 0,
+		&ak4535_mono2_control),
+	/* speaker powersave bit */
+	SND_SOC_DAPM_PGA("Speaker Enable", AK4535_MODE2, 0, 0, NULL, 0),
+	SND_SOC_DAPM_SWITCH("Line Out Enable", SND_SOC_NOPM, 0, 0,
+		&ak4535_line_control),
+	SND_SOC_DAPM_SWITCH("Left HP Enable", SND_SOC_NOPM, 0, 0,
+		&ak4535_hpl_control),
+	SND_SOC_DAPM_SWITCH("Right HP Enable", SND_SOC_NOPM, 0, 0,
+		&ak4535_hpr_control),
+	SND_SOC_DAPM_OUTPUT("LOUT"),
+	SND_SOC_DAPM_OUTPUT("HPL"),
+	SND_SOC_DAPM_OUTPUT("ROUT"),
+	SND_SOC_DAPM_OUTPUT("HPR"),
+	SND_SOC_DAPM_OUTPUT("SPP"),
+	SND_SOC_DAPM_OUTPUT("SPN"),
+	SND_SOC_DAPM_OUTPUT("MOUT1"),
+	SND_SOC_DAPM_OUTPUT("MOUT2"),
+	SND_SOC_DAPM_OUTPUT("MICOUT"),
+	SND_SOC_DAPM_ADC("ADC", "Capture", AK4535_PM1, 0, 0),
+	SND_SOC_DAPM_PGA("Spk Amp", AK4535_PM2, 3, 0, NULL, 0),
+	SND_SOC_DAPM_PGA("HP R Amp", AK4535_PM2, 1, 0, NULL, 0),
+	SND_SOC_DAPM_PGA("HP L Amp", AK4535_PM2, 2, 0, NULL, 0),
+	SND_SOC_DAPM_PGA("Mic", AK4535_PM1, 1, 0, NULL, 0),
+	SND_SOC_DAPM_PGA("Line Out", AK4535_PM1, 4, 0, NULL, 0),
+	SND_SOC_DAPM_PGA("Mono Out", AK4535_PM1, 3, 0, NULL, 0),
+	SND_SOC_DAPM_PGA("AUX In", AK4535_PM1, 2, 0, NULL, 0),
+
+	SND_SOC_DAPM_MICBIAS("Mic Int Bias", AK4535_MIC, 3, 0),
+	SND_SOC_DAPM_MICBIAS("Mic Ext Bias", AK4535_MIC, 4, 0),
+	SND_SOC_DAPM_INPUT("MICIN"),
+	SND_SOC_DAPM_INPUT("MICEXT"),
+	SND_SOC_DAPM_INPUT("AUX"),
+	SND_SOC_DAPM_INPUT("MIN"),
+	SND_SOC_DAPM_INPUT("AIN"),
+};
+
+static const struct snd_soc_dapm_route audio_map[] = {
+	/*stereo mixer */
+	{"Stereo Mixer", "Playback Switch", "DAC"},
+	{"Stereo Mixer", "Mic Sidetone Switch", "Mic"},
+	{"Stereo Mixer", "Aux Bypass Switch", "AUX In"},
+
+	/* mono1 mixer */
+	{"Mono1 Mixer", "Mic Sidetone Switch", "Mic"},
+	{"Mono1 Mixer", "Mono Playback Switch", "DAC"},
+
+	/* Mic */
+	{"Mic", NULL, "AIN"},
+	{"Input Mux", "Internal", "Mic Int Bias"},
+	{"Input Mux", "External", "Mic Ext Bias"},
+	{"Mic Int Bias", NULL, "MICIN"},
+	{"Mic Ext Bias", NULL, "MICEXT"},
+	{"MICOUT", NULL, "Input Mux"},
+
+	/* line out */
+	{"LOUT", NULL, "Line Out Enable"},
+	{"ROUT", NULL, "Line Out Enable"},
+	{"Line Out Enable", "Switch", "Line Out"},
+	{"Line Out", NULL, "Stereo Mixer"},
+
+	/* mono1 out */
+	{"MOUT1", NULL, "Mono Out"},
+	{"Mono Out", NULL, "Mono1 Mixer"},
+
+	/* left HP */
+	{"HPL", NULL, "Left HP Enable"},
+	{"Left HP Enable", "Switch", "HP L Amp"},
+	{"HP L Amp", NULL, "Stereo Mixer"},
+
+	/* right HP */
+	{"HPR", NULL, "Right HP Enable"},
+	{"Right HP Enable", "Switch", "HP R Amp"},
+	{"HP R Amp", NULL, "Stereo Mixer"},
+
+	/* speaker */
+	{"SPP", NULL, "Speaker Enable"},
+	{"SPN", NULL, "Speaker Enable"},
+	{"Speaker Enable", "Switch", "Spk Amp"},
+	{"Spk Amp", NULL, "MIN"},
+
+	/* mono 2 */
+	{"MOUT2", NULL, "Mono 2 Enable"},
+	{"Mono 2 Enable", "Switch", "Stereo Mixer"},
+
+	/* Aux In */
+	{"Aux In", NULL, "AUX"},
+
+	/* ADC */
+	{"ADC", NULL, "Input Mixer"},
+	{"Input Mixer", "Mic Capture Switch", "Mic"},
+	{"Input Mixer", "Aux Capture Switch", "Aux In"},
+};
+
+static int ak4535_add_widgets(struct snd_soc_codec *codec)
+{
+	snd_soc_dapm_new_controls(codec, ak4535_dapm_widgets,
+				  ARRAY_SIZE(ak4535_dapm_widgets));
+
+	snd_soc_dapm_add_routes(codec, audio_map, ARRAY_SIZE(audio_map));
+
+	snd_soc_dapm_new_widgets(codec);
+	return 0;
+}
+
+static int ak4535_set_dai_sysclk(struct snd_soc_codec_dai *codec_dai,
+	int clk_id, unsigned int freq, int dir)
+{
+	struct snd_soc_codec *codec = codec_dai->codec;
+	struct ak4535_priv *ak4535 = codec->private_data;
+
+	ak4535->sysclk = freq;
+	return 0;
+}
+
+static int ak4535_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_device *socdev = rtd->socdev;
+	struct snd_soc_codec *codec = socdev->codec;
+	struct ak4535_priv *ak4535 = codec->private_data;
+	u8 mode2 = ak4535_read_reg_cache(codec, AK4535_MODE2) & ~(0x3 << 5);
+	int rate = params_rate(params), fs = 256;
+
+	if (rate)
+		fs = ak4535->sysclk / rate;
+
+	/* set fs */
+	switch (fs) {
+	case 1024:
+		mode2 |= (0x2 << 5);
+		break;
+	case 512:
+		mode2 |= (0x1 << 5);
+		break;
+	case 256:
+		break;
+	}
+
+	/* set rate */
+	ak4535_write(codec, AK4535_MODE2, mode2);
+	return 0;
+}
+
+static int ak4535_set_dai_fmt(struct snd_soc_codec_dai *codec_dai,
+		unsigned int fmt)
+{
+	struct snd_soc_codec *codec = codec_dai->codec;
+	u8 mode1 = 0;
+
+	/* interface format */
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		mode1 = 0x0002;
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		mode1 = 0x0001;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* use 32 fs for BCLK to save power */
+	mode1 |= 0x4;
+
+	ak4535_write(codec, AK4535_MODE1, mode1);
+	return 0;
+}
+
+static int ak4535_mute(struct snd_soc_codec_dai *dai, int mute)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	u16 mute_reg = ak4535_read_reg_cache(codec, AK4535_DAC) & 0xffdf;
+	if (!mute)
+		ak4535_write(codec, AK4535_DAC, mute_reg);
+	else
+		ak4535_write(codec, AK4535_DAC, mute_reg | 0x20);
+	return 0;
+}
+
+static int ak4535_set_bias_level(struct snd_soc_codec *codec,
+	enum snd_soc_bias_level level)
+{
+	u16 i;
+
+	switch (level) {
+	case SND_SOC_BIAS_ON:
+		ak4535_mute(codec->dai, 0);
+		break;
+	case SND_SOC_BIAS_PREPARE:
+		ak4535_mute(codec->dai, 1);
+		break;
+	case SND_SOC_BIAS_STANDBY:
+		i = ak4535_read_reg_cache(codec, AK4535_PM1);
+		ak4535_write(codec, AK4535_PM1, i | 0x80);
+		i = ak4535_read_reg_cache(codec, AK4535_PM2);
+		ak4535_write(codec, AK4535_PM2, i & (~0x80));
+		break;
+	case SND_SOC_BIAS_OFF:
+		i = ak4535_read_reg_cache(codec, AK4535_PM1);
+		ak4535_write(codec, AK4535_PM1, i & (~0x80));
+		break;
+	}
+	codec->bias_level = level;
+	return 0;
+}
+
+#define AK4535_RATES (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |\
+		SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050 |\
+		SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000)
+
+struct snd_soc_codec_dai ak4535_dai = {
+	.name = "AK4535",
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 1,
+		.channels_max = 2,
+		.rates = AK4535_RATES,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE,},
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 1,
+		.channels_max = 2,
+		.rates = AK4535_RATES,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE,},
+	.ops = {
+		.hw_params = ak4535_hw_params,
+	},
+	.dai_ops = {
+		.set_fmt = ak4535_set_dai_fmt,
+		.digital_mute = ak4535_mute,
+		.set_sysclk = ak4535_set_dai_sysclk,
+	},
+};
+EXPORT_SYMBOL_GPL(ak4535_dai);
+
+static int ak4535_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;
+
+	ak4535_set_bias_level(codec, SND_SOC_BIAS_OFF);
+	return 0;
+}
+
+static int ak4535_resume(struct platform_device *pdev)
+{
+	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+	struct snd_soc_codec *codec = socdev->codec;
+	ak4535_sync(codec);
+	ak4535_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
+	ak4535_set_bias_level(codec, codec->suspend_bias_level);
+	return 0;
+}
+
+/*
+ * initialise the AK4535 driver
+ * register the mixer and dsp interfaces with the kernel
+ */
+static int ak4535_init(struct snd_soc_device *socdev)
+{
+	struct snd_soc_codec *codec = socdev->codec;
+	int ret = 0;
+
+	codec->name = "AK4535";
+	codec->owner = THIS_MODULE;
+	codec->read = ak4535_read_reg_cache;
+	codec->write = ak4535_write;
+	codec->set_bias_level = ak4535_set_bias_level;
+	codec->dai = &ak4535_dai;
+	codec->num_dai = 1;
+	codec->reg_cache_size = ARRAY_SIZE(ak4535_reg);
+	codec->reg_cache = kmemdup(ak4535_reg, sizeof(ak4535_reg), GFP_KERNEL);
+
+	if (codec->reg_cache == NULL)
+		return -ENOMEM;
+
+	/* register pcms */
+	ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
+	if (ret < 0) {
+		printk(KERN_ERR "ak4535: failed to create pcms\n");
+		goto pcm_err;
+	}
+
+	/* power on device */
+	ak4535_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
+
+	ak4535_add_controls(codec);
+	ak4535_add_widgets(codec);
+	ret = snd_soc_register_card(socdev);
+	if (ret < 0) {
+		printk(KERN_ERR "ak4535: failed to register card\n");
+		goto card_err;
+	}
+
+	return ret;
+
+card_err:
+	snd_soc_free_pcms(socdev);
+	snd_soc_dapm_free(socdev);
+pcm_err:
+	kfree(codec->reg_cache);
+
+	return ret;
+}
+
+static struct snd_soc_device *ak4535_socdev;
+
+#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
+
+#define I2C_DRIVERID_AK4535 0xfefe /* liam -  need a proper id */
+
+static unsigned short normal_i2c[] = { 0, I2C_CLIENT_END };
+
+/* Magic definition of all other variables and things */
+I2C_CLIENT_INSMOD;
+
+static struct i2c_driver ak4535_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 ak4535_codec_probe(struct i2c_adapter *adap, int addr, int kind)
+{
+	struct snd_soc_device *socdev = ak4535_socdev;
+	struct ak4535_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 = kmemdup(&client_template, sizeof(client_template), GFP_KERNEL);
+	if (i2c == NULL) {
+		kfree(codec);
+		return -ENOMEM;
+	}
+	i2c_set_clientdata(i2c, codec);
+	codec->control_data = i2c;
+
+	ret = i2c_attach_client(i2c);
+	if (ret < 0) {
+		printk(KERN_ERR "failed to attach codec at addr %x\n", addr);
+		goto err;
+	}
+
+	ret = ak4535_init(socdev);
+	if (ret < 0) {
+		printk(KERN_ERR "failed to initialise AK4535\n");
+		goto err;
+	}
+	return ret;
+
+err:
+	kfree(codec);
+	kfree(i2c);
+	return ret;
+}
+
+static int ak4535_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 ak4535_i2c_attach(struct i2c_adapter *adap)
+{
+	return i2c_probe(adap, &addr_data, ak4535_codec_probe);
+}
+
+/* corgi i2c codec control layer */
+static struct i2c_driver ak4535_i2c_driver = {
+	.driver = {
+		.name = "AK4535 I2C Codec",
+		.owner = THIS_MODULE,
+	},
+	.id =             I2C_DRIVERID_AK4535,
+	.attach_adapter = ak4535_i2c_attach,
+	.detach_client =  ak4535_i2c_detach,
+	.command =        NULL,
+};
+
+static struct i2c_client client_template = {
+	.name =   "AK4535",
+	.driver = &ak4535_i2c_driver,
+};
+#endif
+
+static int ak4535_probe(struct platform_device *pdev)
+{
+	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+	struct ak4535_setup_data *setup;
+	struct snd_soc_codec *codec;
+	struct ak4535_priv *ak4535;
+	int ret = 0;
+
+	printk(KERN_INFO "AK4535 Audio Codec %s", AK4535_VERSION);
+
+	setup = socdev->codec_data;
+	codec = kzalloc(sizeof(struct snd_soc_codec), GFP_KERNEL);
+	if (codec == NULL)
+		return -ENOMEM;
+
+	ak4535 = kzalloc(sizeof(struct ak4535_priv), GFP_KERNEL);
+	if (ak4535 == NULL) {
+		kfree(codec);
+		return -ENOMEM;
+	}
+
+	codec->private_data = ak4535;
+	socdev->codec = codec;
+	mutex_init(&codec->mutex);
+	INIT_LIST_HEAD(&codec->dapm_widgets);
+	INIT_LIST_HEAD(&codec->dapm_paths);
+
+	ak4535_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;
+		codec->hw_read = (hw_read_t)i2c_master_recv;
+		ret = i2c_add_driver(&ak4535_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 ak4535_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)
+		ak4535_set_bias_level(codec, SND_SOC_BIAS_OFF);
+
+	snd_soc_free_pcms(socdev);
+	snd_soc_dapm_free(socdev);
+#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
+	i2c_del_driver(&ak4535_i2c_driver);
+#endif
+	kfree(codec->private_data);
+	kfree(codec);
+
+	return 0;
+}
+
+struct snd_soc_codec_device soc_codec_dev_ak4535 = {
+	.probe = 	ak4535_probe,
+	.remove = 	ak4535_remove,
+	.suspend = 	ak4535_suspend,
+	.resume =	ak4535_resume,
+};
+EXPORT_SYMBOL_GPL(soc_codec_dev_ak4535);
+
+MODULE_DESCRIPTION("Soc AK4535 driver");
+MODULE_AUTHOR("Richard Purdie");
+MODULE_LICENSE("GPL");

sound/soc/codecs/ak4535.h

+/*
+ * ak4535.h  --  AK4535 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 _AK4535_H
+#define _AK4535_H
+
+/* AK4535 register space */
+
+#define AK4535_PM1		0x0
+#define AK4535_PM2		0x1
+#define AK4535_SIG1		0x2
+#define AK4535_SIG2		0x3
+#define AK4535_MODE1		0x4
+#define AK4535_MODE2		0x5
+#define AK4535_DAC		0x6
+#define AK4535_MIC		0x7
+#define AK4535_TIMER		0x8
+#define AK4535_ALC1		0x9
+#define AK4535_ALC2		0xa
+#define AK4535_PGA		0xb
+#define AK4535_LATT		0xc
+#define AK4535_RATT		0xd
+#define AK4535_VOL		0xe
+#define AK4535_STATUS		0xf
+
+#define AK4535_CACHEREGNUM 	0x10
+
+struct ak4535_setup_data {
+	unsigned short i2c_address;
+};
+
+extern struct snd_soc_codec_dai ak4535_dai;
+extern struct snd_soc_codec_device soc_codec_dev_ak4535;
+
+#endif