wm8974.c

Go to the documentation of this file.

/*
 * wm8974.c  --  WM8974 ALSA Soc Audio driver
 *
 * Copyright 2006-2009 Wolfson Microelectronics PLC.
 *
 * Author: Liam Girdwood <[email protected]>
 *
 * 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/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/initval.h>
#include <sound/tlv.h>

#include "wm8974.h"

static const u16 wm8974_reg[WM8974_CACHEREGNUM] = {
    0x0000, 0x0000, 0x0000, 0x0000,
    0x0050, 0x0000, 0x0140, 0x0000,
    0x0000, 0x0000, 0x0000, 0x00ff,
    0x0000, 0x0000, 0x0100, 0x00ff,
    0x0000, 0x0000, 0x012c, 0x002c,
    0x002c, 0x002c, 0x002c, 0x0000,
    0x0032, 0x0000, 0x0000, 0x0000,
    0x0000, 0x0000, 0x0000, 0x0000,
    0x0038, 0x000b, 0x0032, 0x0000,
    0x0008, 0x000c, 0x0093, 0x00e9,
    0x0000, 0x0000, 0x0000, 0x0000,
    0x0003, 0x0010, 0x0000, 0x0000,
    0x0000, 0x0002, 0x0000, 0x0000,
    0x0000, 0x0000, 0x0039, 0x0000,
    0x0000,
};

#define WM8974_POWER1_BIASEN  0x08
#define WM8974_POWER1_BUFIOEN 0x04

#define wm8974_reset(c) snd_soc_write(c, WM8974_RESET, 0)

static const char *wm8974_companding[] = {"Off", "NC", "u-law", "A-law" };
static const char *wm8974_deemp[] = {"None", "32kHz", "44.1kHz", "48kHz" };
static const char *wm8974_eqmode[] = {"Capture", "Playback" };
static const char *wm8974_bw[] = {"Narrow", "Wide" };
static const char *wm8974_eq1[] = {"80Hz", "105Hz", "135Hz", "175Hz" };
static const char *wm8974_eq2[] = {"230Hz", "300Hz", "385Hz", "500Hz" };
static const char *wm8974_eq3[] = {"650Hz", "850Hz", "1.1kHz", "1.4kHz" };
static const char *wm8974_eq4[] = {"1.8kHz", "2.4kHz", "3.2kHz", "4.1kHz" };
static const char *wm8974_eq5[] = {"5.3kHz", "6.9kHz", "9kHz", "11.7kHz" };
static const char *wm8974_alc[] = {"ALC", "Limiter" };

static const struct soc_enum wm8974_enum[] = {
    SOC_ENUM_SINGLE(WM8974_COMP, 1, 4, wm8974_companding), /* adc */
    SOC_ENUM_SINGLE(WM8974_COMP, 3, 4, wm8974_companding), /* dac */
    SOC_ENUM_SINGLE(WM8974_DAC,  4, 4, wm8974_deemp),
    SOC_ENUM_SINGLE(WM8974_EQ1,  8, 2, wm8974_eqmode),

    SOC_ENUM_SINGLE(WM8974_EQ1,  5, 4, wm8974_eq1),
    SOC_ENUM_SINGLE(WM8974_EQ2,  8, 2, wm8974_bw),
    SOC_ENUM_SINGLE(WM8974_EQ2,  5, 4, wm8974_eq2),
    SOC_ENUM_SINGLE(WM8974_EQ3,  8, 2, wm8974_bw),

    SOC_ENUM_SINGLE(WM8974_EQ3,  5, 4, wm8974_eq3),
    SOC_ENUM_SINGLE(WM8974_EQ4,  8, 2, wm8974_bw),
    SOC_ENUM_SINGLE(WM8974_EQ4,  5, 4, wm8974_eq4),
    SOC_ENUM_SINGLE(WM8974_EQ5,  8, 2, wm8974_bw),

    SOC_ENUM_SINGLE(WM8974_EQ5,  5, 4, wm8974_eq5),
    SOC_ENUM_SINGLE(WM8974_ALC3,  8, 2, wm8974_alc),
};

static const char *wm8974_auxmode_text[] = { "Buffer", "Mixer" };

static const struct soc_enum wm8974_auxmode =
    SOC_ENUM_SINGLE(WM8974_INPUT,  3, 2, wm8974_auxmode_text);

static const DECLARE_TLV_DB_SCALE(digital_tlv, -12750, 50, 1);
static const DECLARE_TLV_DB_SCALE(eq_tlv, -1200, 100, 0);
static const DECLARE_TLV_DB_SCALE(inpga_tlv, -1200, 75, 0);
static const DECLARE_TLV_DB_SCALE(spk_tlv, -5700, 100, 0);

static const struct snd_kcontrol_new wm8974_snd_controls[] = {

SOC_SINGLE("Digital Loopback Switch", WM8974_COMP, 0, 1, 0),

SOC_ENUM("DAC Companding", wm8974_enum[1]),
SOC_ENUM("ADC Companding", wm8974_enum[0]),

SOC_ENUM("Playback De-emphasis", wm8974_enum[2]),
SOC_SINGLE("DAC Inversion Switch", WM8974_DAC, 0, 1, 0),

SOC_SINGLE_TLV("PCM Volume", WM8974_DACVOL, 0, 255, 0, digital_tlv),

SOC_SINGLE("High Pass Filter Switch", WM8974_ADC, 8, 1, 0),
SOC_SINGLE("High Pass Cut Off", WM8974_ADC, 4, 7, 0),
SOC_SINGLE("ADC Inversion Switch", WM8974_ADC, 0, 1, 0),

SOC_SINGLE_TLV("Capture Volume", WM8974_ADCVOL,  0, 255, 0, digital_tlv),

SOC_ENUM("Equaliser Function", wm8974_enum[3]),
SOC_ENUM("EQ1 Cut Off", wm8974_enum[4]),
SOC_SINGLE_TLV("EQ1 Volume", WM8974_EQ1,  0, 24, 1, eq_tlv),

SOC_ENUM("Equaliser EQ2 Bandwith", wm8974_enum[5]),
SOC_ENUM("EQ2 Cut Off", wm8974_enum[6]),
SOC_SINGLE_TLV("EQ2 Volume", WM8974_EQ2,  0, 24, 1, eq_tlv),

SOC_ENUM("Equaliser EQ3 Bandwith", wm8974_enum[7]),
SOC_ENUM("EQ3 Cut Off", wm8974_enum[8]),
SOC_SINGLE_TLV("EQ3 Volume", WM8974_EQ3,  0, 24, 1, eq_tlv),

SOC_ENUM("Equaliser EQ4 Bandwith", wm8974_enum[9]),
SOC_ENUM("EQ4 Cut Off", wm8974_enum[10]),
SOC_SINGLE_TLV("EQ4 Volume", WM8974_EQ4,  0, 24, 1, eq_tlv),

SOC_ENUM("Equaliser EQ5 Bandwith", wm8974_enum[11]),
SOC_ENUM("EQ5 Cut Off", wm8974_enum[12]),
SOC_SINGLE_TLV("EQ5 Volume", WM8974_EQ5,  0, 24, 1, eq_tlv),

SOC_SINGLE("DAC Playback Limiter Switch", WM8974_DACLIM1,  8, 1, 0),
SOC_SINGLE("DAC Playback Limiter Decay", WM8974_DACLIM1,  4, 15, 0),
SOC_SINGLE("DAC Playback Limiter Attack", WM8974_DACLIM1,  0, 15, 0),

SOC_SINGLE("DAC Playback Limiter Threshold", WM8974_DACLIM2,  4, 7, 0),
SOC_SINGLE("DAC Playback Limiter Boost", WM8974_DACLIM2,  0, 15, 0),

SOC_SINGLE("ALC Enable Switch", WM8974_ALC1,  8, 1, 0),
SOC_SINGLE("ALC Capture Max Gain", WM8974_ALC1,  3, 7, 0),
SOC_SINGLE("ALC Capture Min Gain", WM8974_ALC1,  0, 7, 0),

SOC_SINGLE("ALC Capture ZC Switch", WM8974_ALC2,  8, 1, 0),
SOC_SINGLE("ALC Capture Hold", WM8974_ALC2,  4, 7, 0),
SOC_SINGLE("ALC Capture Target", WM8974_ALC2,  0, 15, 0),

SOC_ENUM("ALC Capture Mode", wm8974_enum[13]),
SOC_SINGLE("ALC Capture Decay", WM8974_ALC3,  4, 15, 0),
SOC_SINGLE("ALC Capture Attack", WM8974_ALC3,  0, 15, 0),

SOC_SINGLE("ALC Capture Noise Gate Switch", WM8974_NGATE,  3, 1, 0),
SOC_SINGLE("ALC Capture Noise Gate Threshold", WM8974_NGATE,  0, 7, 0),

SOC_SINGLE("Capture PGA ZC Switch", WM8974_INPPGA,  7, 1, 0),
SOC_SINGLE_TLV("Capture PGA Volume", WM8974_INPPGA,  0, 63, 0, inpga_tlv),

SOC_SINGLE("Speaker Playback ZC Switch", WM8974_SPKVOL,  7, 1, 0),
SOC_SINGLE("Speaker Playback Switch", WM8974_SPKVOL,  6, 1, 1),
SOC_SINGLE_TLV("Speaker Playback Volume", WM8974_SPKVOL,  0, 63, 0, spk_tlv),

SOC_ENUM("Aux Mode", wm8974_auxmode),

SOC_SINGLE("Capture Boost(+20dB)", WM8974_ADCBOOST,  8, 1, 0),
SOC_SINGLE("Mono Playback Switch", WM8974_MONOMIX, 6, 1, 1),

/* DAC / ADC oversampling */
SOC_SINGLE("DAC 128x Oversampling Switch", WM8974_DAC, 8, 1, 0),
SOC_SINGLE("ADC 128x Oversampling Switch", WM8974_ADC, 8, 1, 0),
};

/* Speaker Output Mixer */
static const struct snd_kcontrol_new wm8974_speaker_mixer_controls[] = {
SOC_DAPM_SINGLE("Line Bypass Switch", WM8974_SPKMIX, 1, 1, 0),
SOC_DAPM_SINGLE("Aux Playback Switch", WM8974_SPKMIX, 5, 1, 0),
SOC_DAPM_SINGLE("PCM Playback Switch", WM8974_SPKMIX, 0, 1, 0),
};

/* Mono Output Mixer */
static const struct snd_kcontrol_new wm8974_mono_mixer_controls[] = {
SOC_DAPM_SINGLE("Line Bypass Switch", WM8974_MONOMIX, 1, 1, 0),
SOC_DAPM_SINGLE("Aux Playback Switch", WM8974_MONOMIX, 2, 1, 0),
SOC_DAPM_SINGLE("PCM Playback Switch", WM8974_MONOMIX, 0, 1, 0),
};

/* Boost mixer */
static const struct snd_kcontrol_new wm8974_boost_mixer[] = {
SOC_DAPM_SINGLE("Aux Switch", WM8974_INPPGA, 6, 1, 0),
};

/* Input PGA */
static const struct snd_kcontrol_new wm8974_inpga[] = {
SOC_DAPM_SINGLE("Aux Switch", WM8974_INPUT, 2, 1, 0),
SOC_DAPM_SINGLE("MicN Switch", WM8974_INPUT, 1, 1, 0),
SOC_DAPM_SINGLE("MicP Switch", WM8974_INPUT, 0, 1, 0),
};

/* AUX Input boost vol */
static const struct snd_kcontrol_new wm8974_aux_boost_controls =
SOC_DAPM_SINGLE("Aux Volume", WM8974_ADCBOOST, 0, 7, 0);

/* Mic Input boost vol */
static const struct snd_kcontrol_new wm8974_mic_boost_controls =
SOC_DAPM_SINGLE("Mic Volume", WM8974_ADCBOOST, 4, 7, 0);

static const struct snd_soc_dapm_widget wm8974_dapm_widgets[] = {
SND_SOC_DAPM_MIXER("Speaker Mixer", WM8974_POWER3, 2, 0,
    &wm8974_speaker_mixer_controls[0],
    ARRAY_SIZE(wm8974_speaker_mixer_controls)),
SND_SOC_DAPM_MIXER("Mono Mixer", WM8974_POWER3, 3, 0,
    &wm8974_mono_mixer_controls[0],
    ARRAY_SIZE(wm8974_mono_mixer_controls)),
SND_SOC_DAPM_DAC("DAC", "HiFi Playback", WM8974_POWER3, 0, 0),
SND_SOC_DAPM_ADC("ADC", "HiFi Capture", WM8974_POWER2, 0, 0),
SND_SOC_DAPM_PGA("Aux Input", WM8974_POWER1, 6, 0, NULL, 0),
SND_SOC_DAPM_PGA("SpkN Out", WM8974_POWER3, 5, 0, NULL, 0),
SND_SOC_DAPM_PGA("SpkP Out", WM8974_POWER3, 6, 0, NULL, 0),
SND_SOC_DAPM_PGA("Mono Out", WM8974_POWER3, 7, 0, NULL, 0),

SND_SOC_DAPM_MIXER("Input PGA", WM8974_POWER2, 2, 0, wm8974_inpga,
           ARRAY_SIZE(wm8974_inpga)),
SND_SOC_DAPM_MIXER("Boost Mixer", WM8974_POWER2, 4, 0,
           wm8974_boost_mixer, ARRAY_SIZE(wm8974_boost_mixer)),

SND_SOC_DAPM_SUPPLY("Mic Bias", WM8974_POWER1, 4, 0, NULL, 0),

SND_SOC_DAPM_INPUT("MICN"),
SND_SOC_DAPM_INPUT("MICP"),
SND_SOC_DAPM_INPUT("AUX"),
SND_SOC_DAPM_OUTPUT("MONOOUT"),
SND_SOC_DAPM_OUTPUT("SPKOUTP"),
SND_SOC_DAPM_OUTPUT("SPKOUTN"),
};

static const struct snd_soc_dapm_route wm8974_dapm_routes[] = {
    /* Mono output mixer */
    {"Mono Mixer", "PCM Playback Switch", "DAC"},
    {"Mono Mixer", "Aux Playback Switch", "Aux Input"},
    {"Mono Mixer", "Line Bypass Switch", "Boost Mixer"},

    /* Speaker output mixer */
    {"Speaker Mixer", "PCM Playback Switch", "DAC"},
    {"Speaker Mixer", "Aux Playback Switch", "Aux Input"},
    {"Speaker Mixer", "Line Bypass Switch", "Boost Mixer"},

    /* Outputs */
    {"Mono Out", NULL, "Mono Mixer"},
    {"MONOOUT", NULL, "Mono Out"},
    {"SpkN Out", NULL, "Speaker Mixer"},
    {"SpkP Out", NULL, "Speaker Mixer"},
    {"SPKOUTN", NULL, "SpkN Out"},
    {"SPKOUTP", NULL, "SpkP Out"},

    /* Boost Mixer */
    {"ADC", NULL, "Boost Mixer"},
    {"Boost Mixer", "Aux Switch", "Aux Input"},
    {"Boost Mixer", NULL, "Input PGA"},
    {"Boost Mixer", NULL, "MICP"},

    /* Input PGA */
    {"Input PGA", "Aux Switch", "Aux Input"},
    {"Input PGA", "MicN Switch", "MICN"},
    {"Input PGA", "MicP Switch", "MICP"},

    /* Inputs */
    {"Aux Input", NULL, "AUX"},
};

struct pll_ {
    unsigned int pre_div:1;
    unsigned int n:4;
    unsigned int k;
};

/* The size in bits of the pll divide multiplied by 10
 * to allow rounding later */
#define FIXED_PLL_SIZE ((1 << 24) * 10)

static void pll_factors(struct pll_ *pll_div,
            unsigned int target, unsigned int source)
{
    unsigned long long Kpart;
    unsigned int K, Ndiv, Nmod;

    /* There is a fixed divide by 4 in the output path */
    target *= 4;

    Ndiv = target / source;
    if (Ndiv < 6) {
        source /= 2;
        pll_div->pre_div = 1;
        Ndiv = target / source;
    } else
        pll_div->pre_div = 0;

    if ((Ndiv < 6) || (Ndiv > 12))
        printk(KERN_WARNING
            "WM8974 N value %u outwith recommended range!\n",
            Ndiv);

    pll_div->n = Ndiv;
    Nmod = target % source;
    Kpart = FIXED_PLL_SIZE * (long long)Nmod;

    do_div(Kpart, source);

    K = Kpart & 0xFFFFFFFF;

    /* Check if we need to round */
    if ((K % 10) >= 5)
        K += 5;

    /* Move down to proper range now rounding is done */
    K /= 10;

    pll_div->k = K;
}

static int wm8974_set_dai_pll(struct snd_soc_dai *codec_dai, int pll_id,
        int source, unsigned int freq_in, unsigned int freq_out)
{
    struct snd_soc_codec *codec = codec_dai->codec;
    struct pll_ pll_div;
    u16 reg;

    if (freq_in == 0 || freq_out == 0) {
        /* Clock CODEC directly from MCLK */
        reg = snd_soc_read(codec, WM8974_CLOCK);
        snd_soc_write(codec, WM8974_CLOCK, reg & 0x0ff);

        /* Turn off PLL */
        reg = snd_soc_read(codec, WM8974_POWER1);
        snd_soc_write(codec, WM8974_POWER1, reg & 0x1df);
        return 0;
    }

    pll_factors(&pll_div, freq_out, freq_in);

    snd_soc_write(codec, WM8974_PLLN, (pll_div.pre_div << 4) | pll_div.n);
    snd_soc_write(codec, WM8974_PLLK1, pll_div.k >> 18);
    snd_soc_write(codec, WM8974_PLLK2, (pll_div.k >> 9) & 0x1ff);
    snd_soc_write(codec, WM8974_PLLK3, pll_div.k & 0x1ff);
    reg = snd_soc_read(codec, WM8974_POWER1);
    snd_soc_write(codec, WM8974_POWER1, reg | 0x020);

    /* Run CODEC from PLL instead of MCLK */
    reg = snd_soc_read(codec, WM8974_CLOCK);
    snd_soc_write(codec, WM8974_CLOCK, reg | 0x100);

    return 0;
}

/*
 * Configure WM8974 clock dividers.
 */
static int wm8974_set_dai_clkdiv(struct snd_soc_dai *codec_dai,
        int div_id, int div)
{
    struct snd_soc_codec *codec = codec_dai->codec;
    u16 reg;

    switch (div_id) {
    case WM8974_OPCLKDIV:
        reg = snd_soc_read(codec, WM8974_GPIO) & 0x1cf;
        snd_soc_write(codec, WM8974_GPIO, reg | div);
        break;
    case WM8974_MCLKDIV:
        reg = snd_soc_read(codec, WM8974_CLOCK) & 0x11f;
        snd_soc_write(codec, WM8974_CLOCK, reg | div);
        break;
    case WM8974_BCLKDIV:
        reg = snd_soc_read(codec, WM8974_CLOCK) & 0x1e3;
        snd_soc_write(codec, WM8974_CLOCK, reg | div);
        break;
    default:
        return -EINVAL;
    }

    return 0;
}

static int wm8974_set_dai_fmt(struct snd_soc_dai *codec_dai,
        unsigned int fmt)
{
    struct snd_soc_codec *codec = codec_dai->codec;
    u16 iface = 0;
    u16 clk = snd_soc_read(codec, WM8974_CLOCK) & 0x1fe;

    /* set master/slave audio interface */
    switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
    case SND_SOC_DAIFMT_CBM_CFM:
        clk |= 0x0001;
        break;
    case SND_SOC_DAIFMT_CBS_CFS:
        break;
    default:
        return -EINVAL;
    }

    /* interface format */
    switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
    case SND_SOC_DAIFMT_I2S:
        iface |= 0x0010;
        break;
    case SND_SOC_DAIFMT_RIGHT_J:
        break;
    case SND_SOC_DAIFMT_LEFT_J:
        iface |= 0x0008;
        break;
    case SND_SOC_DAIFMT_DSP_A:
        iface |= 0x00018;
        break;
    default:
        return -EINVAL;
    }

    /* clock inversion */
    switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
    case SND_SOC_DAIFMT_NB_NF:
        break;
    case SND_SOC_DAIFMT_IB_IF:
        iface |= 0x0180;
        break;
    case SND_SOC_DAIFMT_IB_NF:
        iface |= 0x0100;
        break;
    case SND_SOC_DAIFMT_NB_IF:
        iface |= 0x0080;
        break;
    default:
        return -EINVAL;
    }

    snd_soc_write(codec, WM8974_IFACE, iface);
    snd_soc_write(codec, WM8974_CLOCK, clk);
    return 0;
}

static int wm8974_pcm_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;
    u16 iface = snd_soc_read(codec, WM8974_IFACE) & 0x19f;
    u16 adn = snd_soc_read(codec, WM8974_ADD) & 0x1f1;

    /* bit size */
    switch (params_format(params)) {
    case SNDRV_PCM_FORMAT_S16_LE:
        break;
    case SNDRV_PCM_FORMAT_S20_3LE:
        iface |= 0x0020;
        break;
    case SNDRV_PCM_FORMAT_S24_LE:
        iface |= 0x0040;
        break;
    case SNDRV_PCM_FORMAT_S32_LE:
        iface |= 0x0060;
        break;
    }

    /* filter coefficient */
    switch (params_rate(params)) {
    case 8000:
        adn |= 0x5 << 1;
        break;
    case 11025:
        adn |= 0x4 << 1;
        break;
    case 16000:
        adn |= 0x3 << 1;
        break;
    case 22050:
        adn |= 0x2 << 1;
        break;
    case 32000:
        adn |= 0x1 << 1;
        break;
    case 44100:
    case 48000:
        break;
    }

    snd_soc_write(codec, WM8974_IFACE, iface);
    snd_soc_write(codec, WM8974_ADD, adn);
    return 0;
}

static int wm8974_mute(struct snd_soc_dai *dai, int mute)
{
    struct snd_soc_codec *codec = dai->codec;
    u16 mute_reg = snd_soc_read(codec, WM8974_DAC) & 0xffbf;

    if (mute)
        snd_soc_write(codec, WM8974_DAC, mute_reg | 0x40);
    else
        snd_soc_write(codec, WM8974_DAC, mute_reg);
    return 0;
}

/* liam need to make this lower power with dapm */
static int wm8974_set_bias_level(struct snd_soc_codec *codec,
    enum snd_soc_bias_level level)
{
    u16 power1 = snd_soc_read(codec, WM8974_POWER1) & ~0x3;

    switch (level) {
    case SND_SOC_BIAS_ON:
    case SND_SOC_BIAS_PREPARE:
        power1 |= 0x1;  /* VMID 50k */
        snd_soc_write(codec, WM8974_POWER1, power1);
        break;

    case SND_SOC_BIAS_STANDBY:
        power1 |= WM8974_POWER1_BIASEN | WM8974_POWER1_BUFIOEN;

        if (codec->dapm.bias_level == SND_SOC_BIAS_OFF) {
            snd_soc_cache_sync(codec);

            /* Initial cap charge at VMID 5k */
            snd_soc_write(codec, WM8974_POWER1, power1 | 0x3);
            mdelay(100);
        }

        power1 |= 0x2;  /* VMID 500k */
        snd_soc_write(codec, WM8974_POWER1, power1);
        break;

    case SND_SOC_BIAS_OFF:
        snd_soc_write(codec, WM8974_POWER1, 0);
        snd_soc_write(codec, WM8974_POWER2, 0);
        snd_soc_write(codec, WM8974_POWER3, 0);
        break;
    }

    codec->dapm.bias_level = level;
    return 0;
}

#define WM8974_RATES (SNDRV_PCM_RATE_8000_48000)

#define WM8974_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE |\
    SNDRV_PCM_FMTBIT_S24_LE)

static const struct snd_soc_dai_ops wm8974_ops = {
    .hw_params = wm8974_pcm_hw_params,
    .digital_mute = wm8974_mute,
    .set_fmt = wm8974_set_dai_fmt,
    .set_clkdiv = wm8974_set_dai_clkdiv,
    .set_pll = wm8974_set_dai_pll,
};

static struct snd_soc_dai_driver wm8974_dai = {
    .name = "wm8974-hifi",
    .playback = {
        .stream_name = "Playback",
        .channels_min = 1,
        .channels_max = 2,   /* Only 1 channel of data */
        .rates = WM8974_RATES,
        .formats = WM8974_FORMATS,},
    .capture = {
        .stream_name = "Capture",
        .channels_min = 1,
        .channels_max = 2,   /* Only 1 channel of data */
        .rates = WM8974_RATES,
        .formats = WM8974_FORMATS,},
    .ops = &wm8974_ops,
    .symmetric_rates = 1,
};

static int wm8974_suspend(struct snd_soc_codec *codec)
{
    wm8974_set_bias_level(codec, SND_SOC_BIAS_OFF);
    return 0;
}

static int wm8974_resume(struct snd_soc_codec *codec)
{
    wm8974_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
    return 0;
}

static int wm8974_probe(struct snd_soc_codec *codec)
{
    int ret = 0;

    ret = snd_soc_codec_set_cache_io(codec, 7, 9, SND_SOC_I2C);
    if (ret < 0) {
        dev_err(codec->dev, "Failed to set cache I/O: %d\n", ret);
        return ret;
    }

    ret = wm8974_reset(codec);
    if (ret < 0) {
        dev_err(codec->dev, "Failed to issue reset\n");
        return ret;
    }

    wm8974_set_bias_level(codec, SND_SOC_BIAS_STANDBY);

    return ret;
}

/* power down chip */
static int wm8974_remove(struct snd_soc_codec *codec)
{
    wm8974_set_bias_level(codec, SND_SOC_BIAS_OFF);
    return 0;
}

static struct snd_soc_codec_driver soc_codec_dev_wm8974 = {
    .probe =    wm8974_probe,
    .remove =   wm8974_remove,
    .suspend =  wm8974_suspend,
    .resume =   wm8974_resume,
    .set_bias_level = wm8974_set_bias_level,
    .reg_cache_size = ARRAY_SIZE(wm8974_reg),
    .reg_word_size = sizeof(u16),
    .reg_cache_default = wm8974_reg,

    .controls = wm8974_snd_controls,
    .num_controls = ARRAY_SIZE(wm8974_snd_controls),
    .dapm_widgets = wm8974_dapm_widgets,
    .num_dapm_widgets = ARRAY_SIZE(wm8974_dapm_widgets),
    .dapm_routes = wm8974_dapm_routes,
    .num_dapm_routes = ARRAY_SIZE(wm8974_dapm_routes),
};

static __devinit int wm8974_i2c_probe(struct i2c_client *i2c,
                      const struct i2c_device_id *id)
{
    int ret;

    ret = snd_soc_register_codec(&i2c->dev,
            &soc_codec_dev_wm8974, &wm8974_dai, 1);

    return ret;
}

static __devexit int wm8974_i2c_remove(struct i2c_client *client)
{
    snd_soc_unregister_codec(&client->dev);

    return 0;
}

static const struct i2c_device_id wm8974_i2c_id[] = {
    { "wm8974", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, wm8974_i2c_id);

static struct i2c_driver wm8974_i2c_driver = {
    .driver = {
        .name = "wm8974",
        .owner = THIS_MODULE,
    },
    .probe =    wm8974_i2c_probe,
    .remove =   __devexit_p(wm8974_i2c_remove),
    .id_table = wm8974_i2c_id,
};

module_i2c_driver(wm8974_i2c_driver);

MODULE_DESCRIPTION("ASoC WM8974 driver");
MODULE_AUTHOR("Liam Girdwood");
MODULE_LICENSE("GPL");