wm8940.c

/*
 * wm8940.c  --  WM8940 ALSA Soc Audio driver
 *
 * Author: Jonathan Cameron <jic23@cam.ac.uk>
 *
 * Based on wm8510.c
 *    Copyright  2006 Wolfson Microelectronics PLC.
 *    Author:  Liam Girdwood <lrg@slimlogic.co.uk>
 *
 * 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.
 *
 * Not currently handled:
 * Notch filter control
 * AUXMode (inverting vs mixer)
 * No means to obtain current gain if alc enabled.
 * No use made of gpio
 * Fast VMID discharge for power down
 * Soft Start
 * DLR and ALR Swaps not enabled
 * Digital Sidetone not supported
 */
#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/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 "wm8940.h"

struct wm8940_priv {
	unsigned int sysclk;
	u16 reg_cache[WM8940_CACHEREGNUM];
	struct snd_soc_codec codec;
};

static u16 wm8940_reg_defaults[] = {
	0x8940, /* Soft Reset */
	0x0000, /* Power 1 */
	0x0000, /* Power 2 */
	0x0000, /* Power 3 */
	0x0010, /* Interface Control */
	0x0000, /* Companding Control */
	0x0140, /* Clock Control */
	0x0000, /* Additional Controls */
	0x0000, /* GPIO Control */
	0x0002, /* Auto Increment Control */
	0x0000, /* DAC Control */
	0x00FF, /* DAC Volume */
	0,
	0,
	0x0100, /* ADC Control */
	0x00FF, /* ADC Volume */
	0x0000, /* Notch Filter 1 Control 1 */
	0x0000, /* Notch Filter 1 Control 2 */
	0x0000, /* Notch Filter 2 Control 1 */
	0x0000, /* Notch Filter 2 Control 2 */
	0x0000, /* Notch Filter 3 Control 1 */
	0x0000, /* Notch Filter 3 Control 2 */
	0x0000, /* Notch Filter 4 Control 1 */
	0x0000, /* Notch Filter 4 Control 2 */
	0x0032, /* DAC Limit Control 1 */
	0x0000, /* DAC Limit Control 2 */
	0,
	0,
	0,
	0,
	0,
	0,
	0x0038, /* ALC Control 1 */
	0x000B, /* ALC Control 2 */
	0x0032, /* ALC Control 3 */
	0x0000, /* Noise Gate */
	0x0041, /* PLLN */
	0x000C, /* PLLK1 */
	0x0093, /* PLLK2 */
	0x00E9, /* PLLK3 */
	0,
	0,
	0x0030, /* ALC Control 4 */
	0,
	0x0002, /* Input Control */
	0x0050, /* PGA Gain */
	0,
	0x0002, /* ADC Boost Control */
	0,
	0x0002, /* Output Control */
	0x0000, /* Speaker Mixer Control */
	0,
	0,
	0,
	0x0079, /* Speaker Volume */
	0,
	0x0000, /* Mono Mixer Control */
};

static inline unsigned int wm8940_read_reg_cache(struct snd_soc_codec *codec,
						 unsigned int reg)
{
	u16 *cache = codec->reg_cache;

	if (reg >= ARRAY_SIZE(wm8940_reg_defaults))
		return -1;

	return cache[reg];
}

static inline int wm8940_write_reg_cache(struct snd_soc_codec *codec,
					  u16 reg, unsigned int value)
{
	u16 *cache = codec->reg_cache;

	if (reg >= ARRAY_SIZE(wm8940_reg_defaults))
		return -1;

	cache[reg] = value;

	return 0;
}

static int wm8940_write(struct snd_soc_codec *codec, unsigned int reg,
			unsigned int value)
{
	int ret;
	u8 data[3] = { reg,
		       (value & 0xff00) >> 8,
		       (value & 0x00ff)
	};

	wm8940_write_reg_cache(codec, reg, value);

	ret = codec->hw_write(codec->control_data, data, 3);

	if (ret < 0)
		return ret;
	else if (ret != 3)
		return -EIO;
	return 0;
}

static const char *wm8940_companding[] = { "Off", "NC", "u-law", "A-law" };
static const struct soc_enum wm8940_adc_companding_enum
= SOC_ENUM_SINGLE(WM8940_COMPANDINGCTL, 1, 4, wm8940_companding);
static const struct soc_enum wm8940_dac_companding_enum
= SOC_ENUM_SINGLE(WM8940_COMPANDINGCTL, 3, 4, wm8940_companding);

static const char *wm8940_alc_mode_text[] = {"ALC", "Limiter"};
static const struct soc_enum wm8940_alc_mode_enum
= SOC_ENUM_SINGLE(WM8940_ALC3, 8, 2, wm8940_alc_mode_text);

static const char *wm8940_mic_bias_level_text[] = {"0.9", "0.65"};
static const struct soc_enum wm8940_mic_bias_level_enum
= SOC_ENUM_SINGLE(WM8940_INPUTCTL, 8, 2, wm8940_mic_bias_level_text);

static const char *wm8940_filter_mode_text[] = {"Audio", "Application"};
static const struct soc_enum wm8940_filter_mode_enum
= SOC_ENUM_SINGLE(WM8940_ADC, 7, 2, wm8940_filter_mode_text);

DECLARE_TLV_DB_SCALE(wm8940_spk_vol_tlv, -5700, 100, 1);
DECLARE_TLV_DB_SCALE(wm8940_att_tlv, -1000, 1000, 0);
DECLARE_TLV_DB_SCALE(wm8940_pga_vol_tlv, -1200, 75, 0);
DECLARE_TLV_DB_SCALE(wm8940_alc_min_tlv, -1200, 600, 0);
DECLARE_TLV_DB_SCALE(wm8940_alc_max_tlv, 675, 600, 0);
DECLARE_TLV_DB_SCALE(wm8940_alc_tar_tlv, -2250, 50, 0);
DECLARE_TLV_DB_SCALE(wm8940_lim_boost_tlv, 0, 100, 0);
DECLARE_TLV_DB_SCALE(wm8940_lim_thresh_tlv, -600, 100, 0);
DECLARE_TLV_DB_SCALE(wm8940_adc_tlv, -12750, 50, 1);
DECLARE_TLV_DB_SCALE(wm8940_capture_boost_vol_tlv, 0, 2000, 0);

static const struct snd_kcontrol_new wm8940_snd_controls[] = {
	SOC_SINGLE("Digital Loopback Switch", WM8940_COMPANDINGCTL,
		   6, 1, 0),
	SOC_ENUM("DAC Companding", wm8940_dac_companding_enum),
	SOC_ENUM("ADC Companding", wm8940_adc_companding_enum),

	SOC_ENUM("ALC Mode", wm8940_alc_mode_enum),
	SOC_SINGLE("ALC Switch", WM8940_ALC1, 8, 1, 0),
	SOC_SINGLE_TLV("ALC Capture Max Gain", WM8940_ALC1,
		       3, 7, 1, wm8940_alc_max_tlv),
	SOC_SINGLE_TLV("ALC Capture Min Gain", WM8940_ALC1,
		       0, 7, 0, wm8940_alc_min_tlv),
	SOC_SINGLE_TLV("ALC Capture Target", WM8940_ALC2,
		       0, 14, 0, wm8940_alc_tar_tlv),
	SOC_SINGLE("ALC Capture Hold", WM8940_ALC2, 4, 10, 0),
	SOC_SINGLE("ALC Capture Decay", WM8940_ALC3, 4, 10, 0),
	SOC_SINGLE("ALC Capture Attach", WM8940_ALC3, 0, 10, 0),
	SOC_SINGLE("ALC ZC Switch", WM8940_ALC4, 1, 1, 0),
	SOC_SINGLE("ALC Capture Noise Gate Switch", WM8940_NOISEGATE,
		   3, 1, 0),
	SOC_SINGLE("ALC Capture Noise Gate Threshold", WM8940_NOISEGATE,
		   0, 7, 0),

	SOC_SINGLE("DAC Playback Limiter Switch", WM8940_DACLIM1, 8, 1, 0),
	SOC_SINGLE("DAC Playback Limiter Attack", WM8940_DACLIM1, 0, 9, 0),
	SOC_SINGLE("DAC Playback Limiter Decay", WM8940_DACLIM1, 4, 11, 0),
	SOC_SINGLE_TLV("DAC Playback Limiter Threshold", WM8940_DACLIM2,
		       4, 9, 1, wm8940_lim_thresh_tlv),
	SOC_SINGLE_TLV("DAC Playback Limiter Boost", WM8940_DACLIM2,
		       0, 12, 0, wm8940_lim_boost_tlv),

	SOC_SINGLE("Capture PGA ZC Switch", WM8940_PGAGAIN, 7, 1, 0),
	SOC_SINGLE_TLV("Capture PGA Volume", WM8940_PGAGAIN,
		       0, 63, 0, wm8940_pga_vol_tlv),
	SOC_SINGLE_TLV("Digital Playback Volume", WM8940_DACVOL,
		       0, 255, 0, wm8940_adc_tlv),
	SOC_SINGLE_TLV("Digital Capture Volume", WM8940_ADCVOL,
		       0, 255, 0, wm8940_adc_tlv),
	SOC_ENUM("Mic Bias Level", wm8940_mic_bias_level_enum),
	SOC_SINGLE_TLV("Capture Boost Volue", WM8940_ADCBOOST,
		       8, 1, 0, wm8940_capture_boost_vol_tlv),
	SOC_SINGLE_TLV("Speaker Playback Volume", WM8940_SPKVOL,
		       0, 63, 0, wm8940_spk_vol_tlv),
	SOC_SINGLE("Speaker Playback Switch", WM8940_SPKVOL,  6, 1, 1),

	SOC_SINGLE_TLV("Speaker Mixer Line Bypass Volume", WM8940_SPKVOL,
		       8, 1, 1, wm8940_att_tlv),
	SOC_SINGLE("Speaker Playback ZC Switch", WM8940_SPKVOL, 7, 1, 0),

	SOC_SINGLE("Mono Out Switch", WM8940_MONOMIX, 6, 1, 1),
	SOC_SINGLE_TLV("Mono Mixer Line Bypass Volume", WM8940_MONOMIX,
		       7, 1, 1, wm8940_att_tlv),

	SOC_SINGLE("High Pass Filter Switch", WM8940_ADC, 8, 1, 0),
	SOC_ENUM("High Pass Filter Mode", wm8940_filter_mode_enum),
	SOC_SINGLE("High Pass Filter Cut Off", WM8940_ADC, 4, 7, 0),
	SOC_SINGLE("ADC Inversion Switch", WM8940_ADC, 0, 1, 0),
	SOC_SINGLE("DAC Inversion Switch", WM8940_DAC, 0, 1, 0),
	SOC_SINGLE("DAC Auto Mute Switch", WM8940_DAC, 2, 1, 0),
	SOC_SINGLE("ZC Timeout Clock Switch", WM8940_ADDCNTRL, 0, 1, 0),
};

static const struct snd_kcontrol_new wm8940_speaker_mixer_controls[] = {
	SOC_DAPM_SINGLE("Line Bypass Switch", WM8940_SPKMIX, 1, 1, 0),
	SOC_DAPM_SINGLE("Aux Playback Switch", WM8940_SPKMIX, 5, 1, 0),
	SOC_DAPM_SINGLE("PCM Playback Switch", WM8940_SPKMIX, 0, 1, 0),
};

static const struct snd_kcontrol_new wm8940_mono_mixer_controls[] = {
	SOC_DAPM_SINGLE("Line Bypass Switch", WM8940_MONOMIX, 1, 1, 0),
	SOC_DAPM_SINGLE("Aux Playback Switch", WM8940_MONOMIX, 2, 1, 0),
	SOC_DAPM_SINGLE("PCM Playback Switch", WM8940_MONOMIX, 0, 1, 0),
};

DECLARE_TLV_DB_SCALE(wm8940_boost_vol_tlv, -1500, 300, 1);
static const struct snd_kcontrol_new wm8940_input_boost_controls[] = {
	SOC_DAPM_SINGLE("Mic PGA Switch", WM8940_PGAGAIN, 6, 1, 1),
	SOC_DAPM_SINGLE_TLV("Aux Volume", WM8940_ADCBOOST,
			    0, 7, 0, wm8940_boost_vol_tlv),
	SOC_DAPM_SINGLE_TLV("Mic Volume", WM8940_ADCBOOST,
			    4, 7, 0, wm8940_boost_vol_tlv),
};

static const struct snd_kcontrol_new wm8940_micpga_controls[] = {
	SOC_DAPM_SINGLE("AUX Switch", WM8940_INPUTCTL, 2, 1, 0),
	SOC_DAPM_SINGLE("MICP Switch", WM8940_INPUTCTL, 0, 1, 0),
	SOC_DAPM_SINGLE("MICN Switch", WM8940_INPUTCTL, 1, 1, 0),
};

static const struct snd_soc_dapm_widget wm8940_dapm_widgets[] = {
	SND_SOC_DAPM_MIXER("Speaker Mixer", WM8940_POWER3, 2, 0,
			   &wm8940_speaker_mixer_controls[0],
			   ARRAY_SIZE(wm8940_speaker_mixer_controls)),
	SND_SOC_DAPM_MIXER("Mono Mixer", WM8940_POWER3, 3, 0,
			   &wm8940_mono_mixer_controls[0],
			   ARRAY_SIZE(wm8940_mono_mixer_controls)),
	SND_SOC_DAPM_DAC("DAC", "HiFi Playback", WM8940_POWER3, 0, 0),

	SND_SOC_DAPM_PGA("SpkN Out", WM8940_POWER3, 5, 0, NULL, 0),
	SND_SOC_DAPM_PGA("SpkP Out", WM8940_POWER3, 6, 0, NULL, 0),
	SND_SOC_DAPM_PGA("Mono Out", WM8940_POWER3, 7, 0, NULL, 0),
	SND_SOC_DAPM_OUTPUT("MONOOUT"),
	SND_SOC_DAPM_OUTPUT("SPKOUTP"),
	SND_SOC_DAPM_OUTPUT("SPKOUTN"),

	SND_SOC_DAPM_PGA("Aux Input", WM8940_POWER1, 6, 0, NULL, 0),
	SND_SOC_DAPM_ADC("ADC", "HiFi Capture", WM8940_POWER2, 0, 0),
	SND_SOC_DAPM_MIXER("Mic PGA", WM8940_POWER2, 2, 0,
			   &wm8940_micpga_controls[0],
			   ARRAY_SIZE(wm8940_micpga_controls)),
	SND_SOC_DAPM_MIXER("Boost Mixer", WM8940_POWER2, 4, 0,
			   &wm8940_input_boost_controls[0],
			   ARRAY_SIZE(wm8940_input_boost_controls)),
	SND_SOC_DAPM_MICBIAS("Mic Bias", WM8940_POWER1, 4, 0),

	SND_SOC_DAPM_INPUT("MICN"),
	SND_SOC_DAPM_INPUT("MICP"),
	SND_SOC_DAPM_INPUT("AUX"),
};

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"},

	/*  Microphone PGA */
	{"Mic PGA", "MICN Switch", "MICN"},
	{"Mic PGA", "MICP Switch", "MICP"},
	{"Mic PGA", "AUX Switch", "AUX"},

	/* Boost Mixer */
	{"Boost Mixer", "Mic PGA Switch", "Mic PGA"},
	{"Boost Mixer", "Mic Volume",  "MICP"},
	{"Boost Mixer", "Aux Volume", "Aux Input"},

	{"ADC", NULL, "Boost Mixer"},
};

static int wm8940_add_widgets(struct snd_soc_codec *codec)
{
	int ret;

	ret = snd_soc_dapm_new_controls(codec, wm8940_dapm_widgets,
					ARRAY_SIZE(wm8940_dapm_widgets));
	if (ret)
		goto error_ret;
	ret = snd_soc_dapm_add_routes(codec, audio_map, ARRAY_SIZE(audio_map));
	if (ret)
		goto error_ret;
	ret = snd_soc_dapm_new_widgets(codec);

error_ret:
	return ret;
}

#define wm8940_reset(c) wm8940_write(c, WM8940_SOFTRESET, 0);

static int wm8940_set_dai_fmt(struct snd_soc_dai *codec_dai,
			      unsigned int fmt)
{
	struct snd_soc_codec *codec = codec_dai->codec;
	u16 iface = wm8940_read_reg_cache(codec, WM8940_IFACE) & 0xFE67;
	u16 clk = wm8940_read_reg_cache(codec, WM8940_CLOCK) & 0x1fe;

	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBM_CFM:
		clk |= 1;
		break;
	case SND_SOC_DAIFMT_CBS_CFS:
		break;
	default:
		return -EINVAL;
	}
	wm8940_write(codec, WM8940_CLOCK, clk);

	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
		iface |= (2 << 3);
		break;
	case SND_SOC_DAIFMT_LEFT_J:
		iface |= (1 << 3);
		break;
	case SND_SOC_DAIFMT_RIGHT_J:
		break;
	case SND_SOC_DAIFMT_DSP_A:
		iface |= (3 << 3);
		break;
	case SND_SOC_DAIFMT_DSP_B:
		iface |= (3 << 3) | (1 << 7);
		break;
	}

	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
	case SND_SOC_DAIFMT_NB_NF:
		break;
	case SND_SOC_DAIFMT_NB_IF:
		iface |= (1 << 7);
		break;
	case SND_SOC_DAIFMT_IB_NF:
		iface |= (1 << 8);
		break;
	case SND_SOC_DAIFMT_IB_IF:
		iface |= (1 << 8) | (1 << 7);
		break;
	}

	wm8940_write(codec, WM8940_IFACE, iface);

	return 0;
}

static int wm8940_i2s_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params,
				struct snd_soc_dai *dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_device *socdev = rtd->socdev;
	struct snd_soc_codec *codec = socdev->card->codec;
	u16 iface = wm8940_read_reg_cache(codec, WM8940_IFACE) & 0xFD9F;
	u16 addcntrl = wm8940_read_reg_cache(codec, WM8940_ADDCNTRL) & 0xFFF1;
	u16 companding =  wm8940_read_reg_cache(codec,
						WM8940_COMPANDINGCTL) & 0xFFDF;
	int ret;

	/* LoutR control */
	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE
	    && params_channels(params) == 2)
		iface |= (1 << 9);

	switch (params_rate(params)) {
	case SNDRV_PCM_RATE_8000:
		addcntrl |= (0x5 << 1);
		break;
	case SNDRV_PCM_RATE_11025:
		addcntrl |= (0x4 << 1);
		break;
	case SNDRV_PCM_RATE_16000:
		addcntrl |= (0x3 << 1);
		break;
	case SNDRV_PCM_RATE_22050:
		addcntrl |= (0x2 << 1);
		break;
	case SNDRV_PCM_RATE_32000:
		addcntrl |= (0x1 << 1);
		break;
	case SNDRV_PCM_RATE_44100:
	case SNDRV_PCM_RATE_48000:
		break;
	}
	ret = wm8940_write(codec, WM8940_ADDCNTRL, addcntrl);
	if (ret)
		goto error_ret;

	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S8:
		companding = companding | (1 << 5);
		break;
	case SNDRV_PCM_FORMAT_S16_LE:
		break;
	case SNDRV_PCM_FORMAT_S20_3LE:
		iface |= (1 << 5);
		break;
	case SNDRV_PCM_FORMAT_S24_LE:
		iface |= (2 << 5);
		break;
	case SNDRV_PCM_FORMAT_S32_LE:
		iface |= (3 << 5);
		break;
	}
	ret = wm8940_write(codec, WM8940_COMPANDINGCTL, companding);
	if (ret)
		goto error_ret;
	ret = wm8940_write(codec, WM8940_IFACE, iface);

error_ret:
	return ret;
}

static int wm8940_mute(struct snd_soc_dai *dai, int mute)
{
	struct snd_soc_codec *codec = dai->codec;
	u16 mute_reg = wm8940_read_reg_cache(codec, WM8940_DAC) & 0xffbf;

	if (mute)
		mute_reg |= 0x40;

	return wm8940_write(codec, WM8940_DAC, mute_reg);
}

static int wm8940_set_bias_level(struct snd_soc_codec *codec,
				 enum snd_soc_bias_level level)
{
	u16 val;
	u16 pwr_reg = wm8940_read_reg_cache(codec, WM8940_POWER1) & 0x1F0;
	int ret = 0;

	switch (level) {
	case SND_SOC_BIAS_ON:
		/* ensure bufioen and biasen */
		pwr_reg |= (1 << 2) | (1 << 3);
		/* Enable thermal shutdown */
		val = wm8940_read_reg_cache(codec, WM8940_OUTPUTCTL);
		ret = wm8940_write(codec, WM8940_OUTPUTCTL, val | 0x2);
		if (ret)
			break;
		/* set vmid to 75k */
		ret = wm8940_write(codec, WM8940_POWER1, pwr_reg | 0x1);
		break;
	case SND_SOC_BIAS_PREPARE:
		/* ensure bufioen and biasen */
		pwr_reg |= (1 << 2) | (1 << 3);
		ret = wm8940_write(codec, WM8940_POWER1, pwr_reg | 0x1);
		break;
	case SND_SOC_BIAS_STANDBY:
		/* ensure bufioen and biasen */
		pwr_reg |= (1 << 2) | (1 << 3);
		/* set vmid to 300k for standby */
		ret = wm8940_write(codec, WM8940_POWER1, pwr_reg | 0x2);
		break;
	case SND_SOC_BIAS_OFF:
		ret = wm8940_write(codec, WM8940_POWER1, pwr_reg);
		break;
	}

	return ret;
}

struct pll_ {
	unsigned int pre_scale:2;
	unsigned int n:4;
	unsigned int k;
};

static struct pll_ pll_div;

/* 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(unsigned int target, unsigned int source)
{
	unsigned long long Kpart;
	unsigned int K, Ndiv, Nmod;
	/* The left shift ist to avoid accuracy loss when right shifting */
	Ndiv = target / source;

	if (Ndiv > 12) {
		source <<= 1;
		/* Multiply by 2 */
		pll_div.pre_scale = 0;
		Ndiv = target / source;
	} else if (Ndiv < 3) {
		source >>= 2;
		/* Divide by 4 */
		pll_div.pre_scale = 3;
		Ndiv = target / source;
	} else if (Ndiv < 6) {
		source >>= 1;
		/* divide by 2 */
		pll_div.pre_scale = 2;
		Ndiv = target / source;
	} else
		pll_div.pre_scale = 1;

	if ((Ndiv < 6) || (Ndiv > 12))
		printk(KERN_WARNING
			"WM8940 N value %d outwith recommended range!d\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;
}

/* Untested at the moment */
static int wm8940_set_dai_pll(struct snd_soc_dai *codec_dai,
		int pll_id, unsigned int freq_in, unsigned int freq_out)
{
	struct snd_soc_codec *codec = codec_dai->codec;
	u16 reg;

	/* Turn off PLL */
	reg = wm8940_read_reg_cache(codec, WM8940_POWER1);
	wm8940_write(codec, WM8940_POWER1, reg & 0x1df);

	if (freq_in == 0 || freq_out == 0) {
		/* Clock CODEC directly from MCLK */
		reg = wm8940_read_reg_cache(codec, WM8940_CLOCK);
		wm8940_write(codec, WM8940_CLOCK, reg & 0x0ff);
		/* Pll power down */
		wm8940_write(codec, WM8940_PLLN, (1 << 7));
		return 0;
	}

	/* Pll is followed by a frequency divide by 4 */
	pll_factors(freq_out*4, freq_in);
	if (pll_div.k)
		wm8940_write(codec, WM8940_PLLN,
			     (pll_div.pre_scale << 4) | pll_div.n | (1 << 6));
	else /* No factional component */
		wm8940_write(codec, WM8940_PLLN,
			     (pll_div.pre_scale << 4) | pll_div.n);
	wm8940_write(codec, WM8940_PLLK1, pll_div.k >> 18);
	wm8940_write(codec, WM8940_PLLK2, (pll_div.k >> 9) & 0x1ff);
	wm8940_write(codec, WM8940_PLLK3, pll_div.k & 0x1ff);
	/* Enable the PLL */
	reg = wm8940_read_reg_cache(codec, WM8940_POWER1);
	wm8940_write(codec, WM8940_POWER1, reg | 0x020);

	/* Run CODEC from PLL instead of MCLK */
	reg = wm8940_read_reg_cache(codec, WM8940_CLOCK);
	wm8940_write(codec, WM8940_CLOCK, reg | 0x100);

	return 0;
}

static int wm8940_set_dai_sysclk(struct snd_soc_dai *codec_dai,
				 int clk_id, unsigned int freq, int dir)
{
	struct snd_soc_codec *codec = codec_dai->codec;
	struct wm8940_priv *wm8940 = codec->private_data;

	switch (freq) {
	case 11289600:
	case 12000000:
	case 12288000:
	case 16934400:
	case 18432000:
		wm8940->sysclk = freq;
		return 0;
	}
	return -EINVAL;
}

static int wm8940_set_dai_clkdiv(struct snd_soc_dai *codec_dai,
				 int div_id, int div)
{
	struct snd_soc_codec *codec = codec_dai->codec;
	u16 reg;
	int ret = 0;

	switch (div_id) {
	case WM8940_BCLKDIV:
		reg = wm8940_read_reg_cache(codec, WM8940_CLOCK) & 0xFFEF3;
		ret = wm8940_write(codec, WM8940_CLOCK, reg | (div << 2));
		break;
	case WM8940_MCLKDIV:
		reg = wm8940_read_reg_cache(codec, WM8940_CLOCK) & 0xFF1F;
		ret = wm8940_write(codec, WM8940_CLOCK, reg | (div << 5));
		break;
	case WM8940_OPCLKDIV:
		reg = wm8940_read_reg_cache(codec, WM8940_ADDCNTRL) & 0xFFCF;
		ret = wm8940_write(codec, WM8940_ADDCNTRL, reg | (div << 4));
		break;
	}
	return ret;
}

#define WM8940_RATES SNDRV_PCM_RATE_8000_48000

#define WM8940_FORMATS (SNDRV_PCM_FMTBIT_S8 |				\
			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 wm8940_dai_ops = {
	.hw_params = wm8940_i2s_hw_params,
	.set_sysclk = wm8940_set_dai_sysclk,
	.digital_mute = wm8940_mute,
	.set_fmt = wm8940_set_dai_fmt,
	.set_clkdiv = wm8940_set_dai_clkdiv,
	.set_pll = wm8940_set_dai_pll,
};

struct snd_soc_dai wm8940_dai = {
	.name = "WM8940",
	.playback = {
		.stream_name = "Playback",
		.channels_min = 1,
		.channels_max = 2,
		.rates = WM8940_RATES,
		.formats = WM8940_FORMATS,
	},
	.capture = {
		.stream_name = "Capture",
		.channels_min = 1,
		.channels_max = 2,
		.rates = WM8940_RATES,
		.formats = WM8940_FORMATS,
	},
	.ops = &wm8940_dai_ops,
	.symmetric_rates = 1,
};
EXPORT_SYMBOL_GPL(wm8940_dai);

static int wm8940_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;

	return wm8940_set_bias_level(codec, SND_SOC_BIAS_OFF);
}

static int wm8940_resume(struct platform_device *pdev)
{
	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
	struct snd_soc_codec *codec = socdev->card->codec;
	int i;
	int ret;
	u8 data[3];
	u16 *cache = codec->reg_cache;

	/* Sync reg_cache with the hardware
	 * Could use auto incremented writes to speed this up
	 */
	for (i = 0; i < ARRAY_SIZE(wm8940_reg_defaults); i++) {
		data[0] = i;
		data[1] = (cache[i] & 0xFF00) >> 8;
		data[2] = cache[i] & 0x00FF;
		ret = codec->hw_write(codec->control_data, data, 3);
		if (ret < 0)
			goto error_ret;
		else if (ret != 3) {
			ret = -EIO;
			goto error_ret;
		}
	}
	ret = wm8940_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
	if (ret)
		goto error_ret;
	ret = wm8940_set_bias_level(codec, codec->suspend_bias_level);

error_ret:
	return ret;
}

static struct snd_soc_codec *wm8940_codec;

static int wm8940_probe(struct platform_device *pdev)
{
	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
	struct snd_soc_codec *codec;

	int ret = 0;

	if (wm8940_codec == NULL) {
		dev_err(&pdev->dev, "Codec device not registered\n");
		return -ENODEV;
	}

	socdev->card->codec = wm8940_codec;
	codec = wm8940_codec;

	mutex_init(&codec->mutex);
	/* 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;
	}

	ret = snd_soc_add_controls(codec, wm8940_snd_controls,
			     ARRAY_SIZE(wm8940_snd_controls));
	if (ret)
		goto error_free_pcms;
	ret = wm8940_add_widgets(codec);
	if (ret)
		goto error_free_pcms;

	ret = snd_soc_init_card(socdev);
	if (ret < 0) {
		dev_err(codec->dev, "failed to register card: %d\n", ret);
		goto error_free_pcms;
	}

	return ret;

error_free_pcms:
	snd_soc_free_pcms(socdev);
	snd_soc_dapm_free(socdev);
pcm_err:
	return ret;
}

static int wm8940_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_wm8940 = {
	.probe = wm8940_probe,
	.remove = wm8940_remove,
	.suspend = wm8940_suspend,
	.resume = wm8940_resume,
};
EXPORT_SYMBOL_GPL(soc_codec_dev_wm8940);

static int wm8940_register(struct wm8940_priv *wm8940)
{
	struct wm8940_setup_data *pdata = wm8940->codec.dev->platform_data;
	struct snd_soc_codec *codec = &wm8940->codec;
	int ret;
	u16 reg;
	if (wm8940_codec) {
		dev_err(codec->dev, "Another WM8940 is registered\n");
		return -EINVAL;
	}

	INIT_LIST_HEAD(&codec->dapm_widgets);
	INIT_LIST_HEAD(&codec->dapm_paths);

	codec->private_data = wm8940;
	codec->name = "WM8940";
	codec->owner = THIS_MODULE;
	codec->read = wm8940_read_reg_cache;
	codec->write = wm8940_write;
	codec->bias_level = SND_SOC_BIAS_OFF;
	codec->set_bias_level = wm8940_set_bias_level;
	codec->dai = &wm8940_dai;
	codec->num_dai = 1;
	codec->reg_cache_size = ARRAY_SIZE(wm8940_reg_defaults);
	codec->reg_cache = &wm8940->reg_cache;

	memcpy(codec->reg_cache, wm8940_reg_defaults,
	       sizeof(wm8940_reg_defaults));

	ret = wm8940_reset(codec);
	if (ret < 0) {
		dev_err(codec->dev, "Failed to issue reset\n");
		return ret;
	}

	wm8940_dai.dev = codec->dev;

	wm8940_set_bias_level(codec, SND_SOC_BIAS_STANDBY);

	ret = wm8940_write(codec, WM8940_POWER1, 0x180);
	if (ret < 0)
		return ret;

	if (!pdata)
		dev_warn(codec->dev, "No platform data supplied\n");
	else {
		reg = wm8940_read_reg_cache(codec, WM8940_OUTPUTCTL);
		ret = wm8940_write(codec, WM8940_OUTPUTCTL, reg | pdata->vroi);
		if (ret < 0)
			return ret;
	}


	wm8940_codec = codec;

	ret = snd_soc_register_codec(codec);
	if (ret) {
		dev_err(codec->dev, "Failed to register codec: %d\n", ret);
		return ret;
	}

	ret = snd_soc_register_dai(&wm8940_dai);
	if (ret) {
		dev_err(codec->dev, "Failed to register DAI: %d\n", ret);
		snd_soc_unregister_codec(codec);
		return ret;
	}

	return 0;
}

static void wm8940_unregister(struct wm8940_priv *wm8940)
{
	wm8940_set_bias_level(&wm8940->codec, SND_SOC_BIAS_OFF);
	snd_soc_unregister_dai(&wm8940_dai);
	snd_soc_unregister_codec(&wm8940->codec);
	kfree(wm8940);
	wm8940_codec = NULL;
}

static int wm8940_i2c_probe(struct i2c_client *i2c,
			    const struct i2c_device_id *id)
{
	struct wm8940_priv *wm8940;
	struct snd_soc_codec *codec;

	wm8940 = kzalloc(sizeof *wm8940, GFP_KERNEL);
	if (wm8940 == NULL)
		return -ENOMEM;

	codec = &wm8940->codec;
	codec->hw_write = (hw_write_t)i2c_master_send;
	i2c_set_clientdata(i2c, wm8940);
	codec->control_data = i2c;
	codec->dev = &i2c->dev;

	return wm8940_register(wm8940);
}

static int wm8940_i2c_remove(struct i2c_client *client)
{
	struct wm8940_priv *wm8940 = i2c_get_clientdata(client);

	wm8940_unregister(wm8940);

	return 0;
}

static const struct i2c_device_id wm8940_i2c_id[] = {
	{ "wm8940", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, wm8940_i2c_id);

static struct i2c_driver wm8940_i2c_driver = {
	.driver = {
		.name = "WM8940 I2C Codec",
		.owner = THIS_MODULE,
	},
	.probe = wm8940_i2c_probe,
	.remove = __devexit_p(wm8940_i2c_remove),
	.id_table = wm8940_i2c_id,
};

static int __init wm8940_modinit(void)
{
	int ret;

	ret = i2c_add_driver(&wm8940_i2c_driver);
	if (ret)
		printk(KERN_ERR "Failed to register WM8940 I2C driver: %d\n",
		       ret);
	return ret;
}
module_init(wm8940_modinit);

static void __exit wm8940_exit(void)
{
	i2c_del_driver(&wm8940_i2c_driver);
}
module_exit(wm8940_exit);

MODULE_DESCRIPTION("ASoC WM8940 driver");
MODULE_AUTHOR("Jonathan Cameron");
MODULE_LICENSE("GPL");