/*
   * wm8974.c  --  WM8974 ALSA Soc Audio driver
   *

   * Copyright 2006-2009 Wolfson Microelectronics PLC.

   *

   * Author: Liam Girdwood <Liam.Girdwood@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.
   */
  
  #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

  struct wm8974_priv {

  	enum snd_soc_control_type control_type;

  };

  #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 audio_map[] = {
  	/* 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"},

  };
  
  static int wm8974_add_widgets(struct snd_soc_codec *codec)
  {

  	struct snd_soc_dapm_context *dapm = &codec->dapm;

  	snd_soc_dapm_new_controls(dapm, wm8974_dapm_widgets,
  				  ARRAY_SIZE(wm8974_dapm_widgets));
  	snd_soc_dapm_add_routes(dapm, audio_map, ARRAY_SIZE(audio_map));

  	return 0;
  }
  
  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!
  ",

  			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
  ", ret);
  		return ret;

  	}

  	ret = wm8974_reset(codec);

  	if (ret < 0) {

  		dev_err(codec->dev, "Failed to issue reset
  ");
  		return ret;

  	}

  	wm8974_set_bias_level(codec, SND_SOC_BIAS_STANDBY);

  	snd_soc_add_controls(codec, wm8974_snd_controls,
  			     ARRAY_SIZE(wm8974_snd_controls));

  	wm8974_add_widgets(codec);

  	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,

  };

  #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)

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

  {

  	struct wm8974_priv *wm8974;

  	int ret;

  	wm8974 = kzalloc(sizeof(struct wm8974_priv), GFP_KERNEL);
  	if (wm8974 == NULL)

  		return -ENOMEM;

  	i2c_set_clientdata(i2c, wm8974);

  	ret = snd_soc_register_codec(&i2c->dev,
  			&soc_codec_dev_wm8974, &wm8974_dai, 1);
  	if (ret < 0)
  		kfree(wm8974);
  	return ret;

  }

  static __devexit int wm8974_i2c_remove(struct i2c_client *client)
  {

  	snd_soc_unregister_codec(&client->dev);
  	kfree(i2c_get_clientdata(client));

  	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,

  };

  #endif

  
  static int __init wm8974_modinit(void)
  {

  	int ret = 0;
  #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
  	ret = i2c_add_driver(&wm8974_i2c_driver);
  	if (ret != 0) {
  		printk(KERN_ERR "Failed to register wm8974 I2C driver: %d
  ",
  		       ret);
  	}
  #endif
  	return ret;

  }
  module_init(wm8974_modinit);
  
  static void __exit wm8974_exit(void)
  {

  #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)

  	i2c_del_driver(&wm8974_i2c_driver);

  #endif

  }
  module_exit(wm8974_exit);
  
  MODULE_DESCRIPTION("ASoC WM8974 driver");
  MODULE_AUTHOR("Liam Girdwood");
  MODULE_LICENSE("GPL");