ASoC: Add WM8776 CODEC driver

The WM8776 is a high performance, stereo audio CODEC with five channel
input selector. The WM8776 is ideal for surround sound processing
applications for home hi-fi, DVD-RW and other audio visual equipment.

This driver implements support for most WM8776 features - currently the
ADC automatic level control/limiter functionality is omitted.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 781 insertions, 0 deletions

diff --git a/sound/soc/codecs/wm8776.c b/sound/soc/codecs/wm8776.c
new file mode 100644
index 000000000000..ee12bf824a40
--- /dev/null
+++ b/sound/soc/codecs/wm8776.c
@@ -0,0 +1,781 @@
+/*
+ * wm8776.c  --  WM8776 ALSA SoC Audio driver
+ *
+ * Copyright 2009 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.
+ *
+ * TODO: Input ALC/limiter support
+ */
+
+#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/spi/spi.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 <sound/tlv.h>
+
+#include "wm8776.h"
+
+static struct snd_soc_codec *wm8776_codec;
+struct snd_soc_codec_device soc_codec_dev_wm8776;
+
+/* codec private data */
+struct wm8776_priv {
+        struct snd_soc_codec codec;
+        u16 reg_cache[WM8776_CACHEREGNUM];
+        int sysclk[2];
+};
+
+#ifdef CONFIG_SPI_MASTER
+static int wm8776_spi_write(struct spi_device *spi, const char *data, int len);
+#endif
+
+static const u16 wm8776_reg[WM8776_CACHEREGNUM] = {
+        0x79, 0x79, 0x79, 0xff, 0xff,  /* 4 */
+        0xff, 0x00, 0x90, 0x00, 0x00,  /* 9 */
+        0x22, 0x22, 0x22, 0x08, 0xcf,  /* 14 */
+        0xcf, 0x7b, 0x00, 0x32, 0x00,  /* 19 */
+        0xa6, 0x01, 0x01
+};
+
+/*
+ * read wm8776 register cache
+ */
+static inline unsigned int wm8776_read_reg_cache(struct snd_soc_codec *codec,
+        unsigned int reg)
+{
+        u16 *cache = codec->reg_cache;
+        if (reg >= WM8776_CACHEREGNUM)
+                return -1;
+        return cache[reg];
+}
+
+/*
+ * write wm8776 register cache
+ */
+static inline void wm8776_write_reg_cache(struct snd_soc_codec *codec,
+                                          u16 reg, unsigned int value)
+{
+        u16 *cache = codec->reg_cache;
+        if (reg >= WM8776_CACHEREGNUM)
+                return;
+        cache[reg] = value;
+}
+
+/*
+ * write to the WM8776 register space
+ */
+static int wm8776_write(struct snd_soc_codec *codec, unsigned int reg,
+        unsigned int value)
+{
+        u8 data[2];
+
+        data[0] = (reg << 1) | ((value >> 8) & 0x0001);
+        data[1] = value & 0x00ff;
+
+        wm8776_write_reg_cache(codec, reg, value);
+        if (codec->hw_write(codec->control_data, data, 2) == 2)
+                return 0;
+        else
+                return -EIO;
+}
+
+static int wm8776_reset(struct snd_soc_codec *codec)
+{
+        return wm8776_write(codec, WM8776_RESET, 0);
+}
+
+static const DECLARE_TLV_DB_SCALE(hp_tlv, -12100, 100, 1);
+static const DECLARE_TLV_DB_SCALE(dac_tlv, -12750, 50, 1);
+static const DECLARE_TLV_DB_SCALE(adc_tlv, -10350, 50, 1);
+
+static const struct snd_kcontrol_new wm8776_snd_controls[] = {
+SOC_DOUBLE_R_TLV("Headphone Playback Volume", WM8776_HPLVOL, WM8776_HPRVOL,
+                 0, 127, 0, hp_tlv),
+SOC_DOUBLE_R_TLV("Digital Playback Volume", WM8776_DACLVOL, WM8776_DACRVOL,
+                 0, 255, 0, dac_tlv),
+SOC_SINGLE("Digital Playback ZC Switch", WM8776_DACCTRL1, 0, 1, 0),
+
+SOC_SINGLE("Deemphasis Switch", WM8776_DACCTRL2, 0, 1, 0),
+
+SOC_DOUBLE_R_TLV("Capture Volume", WM8776_ADCLVOL, WM8776_ADCRVOL,
+                 0, 255, 0, adc_tlv),
+SOC_DOUBLE("Capture Switch", WM8776_ADCMUX, 7, 6, 1, 1),
+SOC_DOUBLE_R("Capture ZC Switch", WM8776_ADCLVOL, WM8776_ADCRVOL, 8, 1, 0),
+SOC_SINGLE("Capture HPF Switch", WM8776_ADCIFCTRL, 8, 1, 1),
+};
+
+static const struct snd_kcontrol_new inmix_controls[] = {
+SOC_DAPM_SINGLE("AIN1 Switch", WM8776_ADCMUX, 0, 1, 0),
+SOC_DAPM_SINGLE("AIN2 Switch", WM8776_ADCMUX, 1, 1, 0),
+SOC_DAPM_SINGLE("AIN3 Switch", WM8776_ADCMUX, 2, 1, 0),
+SOC_DAPM_SINGLE("AIN4 Switch", WM8776_ADCMUX, 3, 1, 0),
+SOC_DAPM_SINGLE("AIN5 Switch", WM8776_ADCMUX, 4, 1, 0),
+};
+
+static const struct snd_kcontrol_new outmix_controls[] = {
+SOC_DAPM_SINGLE("DAC Switch", WM8776_OUTMUX, 0, 1, 0),
+SOC_DAPM_SINGLE("AUX Switch", WM8776_OUTMUX, 1, 1, 0),
+SOC_DAPM_SINGLE("Bypass Switch", WM8776_OUTMUX, 2, 1, 0),
+};
+
+static const struct snd_soc_dapm_widget wm8776_dapm_widgets[] = {
+SND_SOC_DAPM_INPUT("AUX"),
+SND_SOC_DAPM_INPUT("AUX"),
+
+SND_SOC_DAPM_INPUT("AIN1"),
+SND_SOC_DAPM_INPUT("AIN2"),
+SND_SOC_DAPM_INPUT("AIN3"),
+SND_SOC_DAPM_INPUT("AIN4"),
+SND_SOC_DAPM_INPUT("AIN5"),
+
+SND_SOC_DAPM_MIXER("Input Mixer", WM8776_PWRDOWN, 6, 1,
+                   inmix_controls, ARRAY_SIZE(inmix_controls)),
+
+SND_SOC_DAPM_ADC("ADC", "Capture", WM8776_PWRDOWN, 1, 1),
+SND_SOC_DAPM_DAC("DAC", "Playback", WM8776_PWRDOWN, 2, 1),
+
+SND_SOC_DAPM_MIXER("Output Mixer", SND_SOC_NOPM, 0, 0,
+                   outmix_controls, ARRAY_SIZE(outmix_controls)),
+
+SND_SOC_DAPM_PGA("Headphone PGA", WM8776_PWRDOWN, 3, 1, NULL, 0),
+
+SND_SOC_DAPM_OUTPUT("VOUT"),
+
+SND_SOC_DAPM_OUTPUT("HPOUTL"),
+SND_SOC_DAPM_OUTPUT("HPOUTR"),
+};
+
+static const struct snd_soc_dapm_route routes[] = {
+        { "Input Mixer", "AIN1 Switch", "AIN1" },
+        { "Input Mixer", "AIN2 Switch", "AIN2" },
+        { "Input Mixer", "AIN3 Switch", "AIN3" },
+        { "Input Mixer", "AIN4 Switch", "AIN4" },
+        { "Input Mixer", "AIN5 Switch", "AIN5" },
+
+        { "ADC", NULL, "Input Mixer" },
+
+        { "Output Mixer", "DAC Switch", "DAC" },
+        { "Output Mixer", "AUX Switch", "AUX" },
+        { "Output Mixer", "Bypass Switch", "Input Mixer" },
+
+        { "VOUT", NULL, "Output Mixer" },
+
+        { "Headphone PGA", NULL, "Output Mixer" },
+
+        { "HPOUTL", NULL, "Headphone PGA" },
+        { "HPOUTR", NULL, "Headphone PGA" },
+};
+
+static int wm8776_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+        struct snd_soc_codec *codec = dai->codec;
+        int reg, iface, master;
+
+        switch (dai->id) {
+        case WM8776_DAI_DAC:
+                reg = WM8776_DACIFCTRL;
+                master = 0x80;
+                break;
+        case WM8776_DAI_ADC:
+                reg = WM8776_ADCIFCTRL;
+                master = 0x100;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        iface = 0;
+
+        switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+        case SND_SOC_DAIFMT_CBM_CFM:
+                break;
+        case SND_SOC_DAIFMT_CBS_CFS:
+                master = 0;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        switch (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;
+                /* FIXME: CHECK A/B */
+        case SND_SOC_DAIFMT_DSP_A:
+                iface |= 0x0003;
+                break;
+        case SND_SOC_DAIFMT_DSP_B:
+                iface |= 0x0007;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+        case SND_SOC_DAIFMT_NB_NF:
+                break;
+        case SND_SOC_DAIFMT_IB_IF:
+                iface |= 0x00c;
+                break;
+        case SND_SOC_DAIFMT_IB_NF:
+                iface |= 0x008;
+                break;
+        case SND_SOC_DAIFMT_NB_IF:
+                iface |= 0x004;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        /* Finally, write out the values */
+        snd_soc_update_bits(codec, reg, 0xf, iface);
+        snd_soc_update_bits(codec, WM8776_MSTRCTRL, 0x180, master);
+
+        return 0;
+}
+
+static int mclk_ratios[] = {
+        128,
+        192,
+        256,
+        384,
+        512,
+        768,
+};
+
+static int wm8776_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 wm8776_priv *wm8776 = codec->private_data;
+        int iface_reg, iface;
+        int ratio_shift, master;
+        int i;
+
+        iface = 0;
+
+        switch (dai->id) {
+        case WM8776_DAI_DAC:
+                iface_reg = WM8776_DACIFCTRL;
+                master = 0x80;
+                ratio_shift = 4;
+                break;
+        case WM8776_DAI_ADC:
+                iface_reg = WM8776_ADCIFCTRL;
+                master = 0x100;
+                ratio_shift = 0;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+
+        /* Set word length */
+        switch (params_format(params)) {
+        case SNDRV_PCM_FORMAT_S16_LE:
+                break;
+        case SNDRV_PCM_FORMAT_S20_3LE:
+                iface |= 0x10;
+                break;
+        case SNDRV_PCM_FORMAT_S24_LE:
+                iface |= 0x20;
+                break;
+        case SNDRV_PCM_FORMAT_S32_LE:
+                iface |= 0x30;
+                break;
+        }
+
+        /* Only need to set MCLK/LRCLK ratio if we're master */
+        if (snd_soc_read(codec, WM8776_MSTRCTRL) & master) {
+                for (i = 0; i < ARRAY_SIZE(mclk_ratios); i++) {
+                        if (wm8776->sysclk[dai->id] / params_rate(params)
+                            == mclk_ratios[i])
+                                break;
+                }
+
+                if (i == ARRAY_SIZE(mclk_ratios)) {
+                        dev_err(codec->dev,
+                                "Unable to configure MCLK ratio %d/%d\n",
+                                wm8776->sysclk[dai->id], params_rate(params));
+                        return -EINVAL;
+                }
+
+                dev_dbg(codec->dev, "MCLK is %dfs\n", mclk_ratios[i]);
+
+                snd_soc_update_bits(codec, WM8776_MSTRCTRL,
+                                    0x7 << ratio_shift, i << ratio_shift);
+        } else {
+                dev_dbg(codec->dev, "DAI in slave mode\n");
+        }
+
+        snd_soc_update_bits(codec, iface_reg, 0x30, iface);
+
+        return 0;
+}
+
+static int wm8776_mute(struct snd_soc_dai *dai, int mute)
+{
+        struct snd_soc_codec *codec = dai->codec;
+
+        return snd_soc_write(codec, WM8776_DACMUTE, !!mute);
+}
+
+static int wm8776_set_sysclk(struct snd_soc_dai *dai,
+                             int clk_id, unsigned int freq, int dir)
+{
+        struct snd_soc_codec *codec = dai->codec;
+        struct wm8776_priv *wm8776 = codec->private_data;
+
+        BUG_ON(dai->id >= ARRAY_SIZE(wm8776->sysclk));
+
+        wm8776->sysclk[dai->id] = freq;
+
+        return 0;
+}
+
+static int wm8776_set_bias_level(struct snd_soc_codec *codec,
+                                 enum snd_soc_bias_level level)
+{
+        switch (level) {
+        case SND_SOC_BIAS_ON:
+                break;
+        case SND_SOC_BIAS_PREPARE:
+                break;
+        case SND_SOC_BIAS_STANDBY:
+                if (codec->bias_level == SND_SOC_BIAS_OFF) {
+                        /* Disable the global powerdown; DAPM does the rest */
+                        snd_soc_update_bits(codec, WM8776_PWRDOWN, 1, 0);
+                }
+
+                break;
+        case SND_SOC_BIAS_OFF:
+                snd_soc_update_bits(codec, WM8776_PWRDOWN, 1, 1);
+                break;
+        }
+
+        codec->bias_level = level;
+        return 0;
+}
+
+#define WM8776_RATES (SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |\
+                      SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 |\
+                      SNDRV_PCM_RATE_96000)
+
+
+#define WM8776_FORMATS (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_ops wm8776_dac_ops = {
+        .digital_mute   = wm8776_mute,
+        .hw_params      = wm8776_hw_params,
+        .set_fmt        = wm8776_set_fmt,
+        .set_sysclk     = wm8776_set_sysclk,
+};
+
+static struct snd_soc_dai_ops wm8776_adc_ops = {
+        .hw_params      = wm8776_hw_params,
+        .set_fmt        = wm8776_set_fmt,
+        .set_sysclk     = wm8776_set_sysclk,
+};
+
+struct snd_soc_dai wm8776_dai[] = {
+        {
+                .name = "WM8776 Playback",
+                .id = WM8776_DAI_DAC,
+                .playback = {
+                        .stream_name = "Playback",
+                        .channels_min = 2,
+                        .channels_max = 2,
+                        .rates = WM8776_RATES,
+                        .formats = WM8776_FORMATS,
+                },
+                .ops = &wm8776_dac_ops,
+        },
+        {
+                .name = "WM8776 Capture",
+                .id = WM8776_DAI_ADC,
+                .capture = {
+                        .stream_name = "Capture",
+                        .channels_min = 2,
+                        .channels_max = 2,
+                        .rates = WM8776_RATES,
+                        .formats = WM8776_FORMATS,
+                },
+                .ops = &wm8776_adc_ops,
+        },
+};
+EXPORT_SYMBOL_GPL(wm8776_dai);
+
+#ifdef CONFIG_PM
+static int wm8776_suspend(struct platform_device *pdev, pm_message_t state)
+{
+        struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+        struct snd_soc_codec *codec = socdev->card->codec;
+
+        wm8776_set_bias_level(codec, SND_SOC_BIAS_OFF);
+
+        return 0;
+}
+
+static int wm8776_resume(struct platform_device *pdev)
+{
+        struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+        struct snd_soc_codec *codec = socdev->card->codec;
+        int i;
+        u8 data[2];
+        u16 *cache = codec->reg_cache;
+
+        /* Sync reg_cache with the hardware */
+        for (i = 0; i < ARRAY_SIZE(wm8776_reg); i++) {
+                data[0] = (i << 1) | ((cache[i] >> 8) & 0x0001);
+                data[1] = cache[i] & 0x00ff;
+                codec->hw_write(codec->control_data, data, 2);
+        }
+
+        wm8776_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
+
+        return 0;
+}
+#else
+#define wm8776_suspend NULL
+#define wm8776_resume NULL
+#endif
+
+static int wm8776_probe(struct platform_device *pdev)
+{
+        struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+        struct snd_soc_codec *codec;
+        int ret = 0;
+
+        if (wm8776_codec == NULL) {
+                dev_err(&pdev->dev, "Codec device not registered\n");
+                return -ENODEV;
+        }
+
+        socdev->card->codec = wm8776_codec;
+        codec = wm8776_codec;
+
+        /* register pcms */
+        ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
+        if (ret < 0) {
+                dev_err(codec->dev, "failed to create pcms: %d\n", ret);
+                goto pcm_err;
+        }
+
+        snd_soc_add_controls(codec, wm8776_snd_controls,
+                             ARRAY_SIZE(wm8776_snd_controls));
+        snd_soc_dapm_new_controls(codec, wm8776_dapm_widgets,
+                                  ARRAY_SIZE(wm8776_dapm_widgets));
+        snd_soc_dapm_add_routes(codec, routes, ARRAY_SIZE(routes));
+
+        ret = snd_soc_init_card(socdev);
+        if (ret < 0) {
+                dev_err(codec->dev, "failed to register card: %d\n", ret);
+                goto card_err;
+        }
+
+        return ret;
+
+card_err:
+        snd_soc_free_pcms(socdev);
+        snd_soc_dapm_free(socdev);
+pcm_err:
+        return ret;
+}
+
+/* power down chip */
+static int wm8776_remove(struct platform_device *pdev)
+{
+        struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+
+        snd_soc_free_pcms(socdev);
+        snd_soc_dapm_free(socdev);
+
+        return 0;
+}
+
+struct snd_soc_codec_device soc_codec_dev_wm8776 = {
+        .probe =        wm8776_probe,
+        .remove =       wm8776_remove,
+        .suspend =      wm8776_suspend,
+        .resume =       wm8776_resume,
+};
+EXPORT_SYMBOL_GPL(soc_codec_dev_wm8776);
+
+static int wm8776_register(struct wm8776_priv *wm8776)
+{
+        int ret, i;
+        struct snd_soc_codec *codec = &wm8776->codec;
+
+        if (wm8776_codec) {
+                dev_err(codec->dev, "Another WM8776 is registered\n");
+                ret = -EINVAL;
+                goto err;
+        }
+
+        mutex_init(&codec->mutex);
+        INIT_LIST_HEAD(&codec->dapm_widgets);
+        INIT_LIST_HEAD(&codec->dapm_paths);
+
+        codec->private_data = wm8776;
+        codec->name = "WM8776";
+        codec->owner = THIS_MODULE;
+        codec->read = wm8776_read_reg_cache;
+        codec->write = wm8776_write;
+        codec->bias_level = SND_SOC_BIAS_OFF;
+        codec->set_bias_level = wm8776_set_bias_level;
+        codec->dai = wm8776_dai;
+        codec->num_dai = ARRAY_SIZE(wm8776_dai);
+        codec->reg_cache_size = WM8776_CACHEREGNUM;
+        codec->reg_cache = &wm8776->reg_cache;
+
+        memcpy(codec->reg_cache, wm8776_reg, sizeof(wm8776_reg));
+
+        for (i = 0; i < ARRAY_SIZE(wm8776_dai); i++)
+                wm8776_dai[i].dev = codec->dev;
+
+        ret = wm8776_reset(codec);
+        if (ret < 0) {
+                dev_err(codec->dev, "Failed to issue reset: %d\n", ret);
+                goto err;
+        }
+
+        wm8776_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
+
+        /* Latch the update bits; right channel only since we always
+         * update both. */
+        snd_soc_update_bits(codec, WM8776_HPRVOL, 0x100, 0x100);
+        snd_soc_update_bits(codec, WM8776_DACRVOL, 0x100, 0x100);
+
+        wm8776_codec = codec;
+
+        ret = snd_soc_register_codec(codec);
+        if (ret != 0) {
+                dev_err(codec->dev, "Failed to register codec: %d\n", ret);
+                goto err;
+        }
+
+        ret = snd_soc_register_dais(wm8776_dai, ARRAY_SIZE(wm8776_dai));
+        if (ret != 0) {
+                dev_err(codec->dev, "Failed to register DAIs: %d\n", ret);
+                goto err_codec;
+        }
+
+        return 0;
+
+err_codec:
+        snd_soc_unregister_codec(codec);
+err:
+        kfree(wm8776);
+        return ret;
+}
+
+static void wm8776_unregister(struct wm8776_priv *wm8776)
+{
+        wm8776_set_bias_level(&wm8776->codec, SND_SOC_BIAS_OFF);
+        snd_soc_unregister_dais(wm8776_dai, ARRAY_SIZE(wm8776_dai));
+        snd_soc_unregister_codec(&wm8776->codec);
+        kfree(wm8776);
+        wm8776_codec = NULL;
+}
+
+#if defined(CONFIG_SPI_MASTER)
+static int wm8776_spi_write(struct spi_device *spi, const char *data, int len)
+{
+        struct spi_transfer t;
+        struct spi_message m;
+        u8 msg[2];
+
+        if (len <= 0)
+                return 0;
+
+        msg[0] = data[0];
+        msg[1] = data[1];
+
+        spi_message_init(&m);
+        memset(&t, 0, (sizeof t));
+
+        t.tx_buf = &msg[0];
+        t.len = len;
+
+        spi_message_add_tail(&t, &m);
+        spi_sync(spi, &m);
+
+        return len;
+}
+
+static int __devinit wm8776_spi_probe(struct spi_device *spi)
+{
+        struct snd_soc_codec *codec;
+        struct wm8776_priv *wm8776;
+
+        wm8776 = kzalloc(sizeof(struct wm8776_priv), GFP_KERNEL);
+        if (wm8776 == NULL)
+                return -ENOMEM;
+
+        codec = &wm8776->codec;
+        codec->control_data = spi;
+        codec->hw_write = (hw_write_t)wm8776_spi_write;
+        codec->dev = &spi->dev;
+
+        dev_set_drvdata(&spi->dev, wm8776);
+
+        return wm8776_register(wm8776);
+}
+
+static int __devexit wm8776_spi_remove(struct spi_device *spi)
+{
+        struct wm8776_priv *wm8776 = dev_get_drvdata(&spi->dev);
+
+        wm8776_unregister(wm8776);
+
+        return 0;
+}
+
+#ifdef CONFIG_PM
+static int wm8776_spi_suspend(struct spi_device *spi, pm_message_t msg)
+{
+        return snd_soc_suspend_device(&spi->dev);
+}
+
+static int wm8776_spi_resume(struct spi_device *spi)
+{
+        return snd_soc_resume_device(&spi->dev);
+}
+#else
+#define wm8776_spi_suspend NULL
+#define wm8776_spi_resume NULL
+#endif
+
+static struct spi_driver wm8776_spi_driver = {
+        .driver = {
+                .name   = "wm8776",
+                .bus    = &spi_bus_type,
+                .owner  = THIS_MODULE,
+        },
+        .probe          = wm8776_spi_probe,
+        .suspend        = wm8776_spi_suspend,
+        .resume         = wm8776_spi_resume,
+        .remove         = __devexit_p(wm8776_spi_remove),
+};
+#endif /* CONFIG_SPI_MASTER */
+
+#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
+static __devinit int wm8776_i2c_probe(struct i2c_client *i2c,
+                                      const struct i2c_device_id *id)
+{
+        struct wm8776_priv *wm8776;
+        struct snd_soc_codec *codec;
+
+        wm8776 = kzalloc(sizeof(struct wm8776_priv), GFP_KERNEL);
+        if (wm8776 == NULL)
+                return -ENOMEM;
+
+        codec = &wm8776->codec;
+        codec->hw_write = (hw_write_t)i2c_master_send;
+
+        i2c_set_clientdata(i2c, wm8776);
+        codec->control_data = i2c;
+
+        codec->dev = &i2c->dev;
+
+        return wm8776_register(wm8776);
+}
+
+static __devexit int wm8776_i2c_remove(struct i2c_client *client)
+{
+        struct wm8776_priv *wm8776 = i2c_get_clientdata(client);
+        wm8776_unregister(wm8776);
+        return 0;
+}
+
+#ifdef CONFIG_PM
+static int wm8776_i2c_suspend(struct i2c_client *i2c, pm_message_t msg)
+{
+        return snd_soc_suspend_device(&i2c->dev);
+}
+
+static int wm8776_i2c_resume(struct i2c_client *i2c)
+{
+        return snd_soc_resume_device(&i2c->dev);
+}
+#else
+#define wm8776_i2c_suspend NULL
+#define wm8776_i2c_resume NULL
+#endif
+
+static const struct i2c_device_id wm8776_i2c_id[] = {
+        { "wm8776", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, wm8776_i2c_id);
+
+static struct i2c_driver wm8776_i2c_driver = {
+        .driver = {
+                .name = "wm8776",
+                .owner = THIS_MODULE,
+        },
+        .probe =    wm8776_i2c_probe,
+        .remove =   __devexit_p(wm8776_i2c_remove),
+        .suspend =  wm8776_i2c_suspend,
+        .resume =   wm8776_i2c_resume,
+        .id_table = wm8776_i2c_id,
+};
+#endif
+
+static int __init wm8776_modinit(void)
+{
+        int ret;
+#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
+        ret = i2c_add_driver(&wm8776_i2c_driver);
+        if (ret != 0) {
+                printk(KERN_ERR "Failed to register WM8776 I2C driver: %d\n",
+                       ret);
+        }
+#endif
+#if defined(CONFIG_SPI_MASTER)
+        ret = spi_register_driver(&wm8776_spi_driver);
+        if (ret != 0) {
+                printk(KERN_ERR "Failed to register WM8776 SPI driver: %d\n",
+                       ret);
+        }
+#endif
+        return 0;
+}
+module_init(wm8776_modinit);
+
+static void __exit wm8776_exit(void)
+{
+#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
+        i2c_del_driver(&wm8776_i2c_driver);
+#endif
+#if defined(CONFIG_SPI_MASTER)
+        spi_unregister_driver(&wm8776_spi_driver);
+#endif
+}
+module_exit(wm8776_exit);
+
+MODULE_DESCRIPTION("ASoC WM8776 driver");
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_LICENSE("GPL");