sound/soc/codecs/cx20442.c - kernel/bruno - Git at Google

 /*
  * cx20442.c  --  CX20442 ALSA Soc Audio driver
  *
  * Copyright 2009 Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
  *
  * Initially based on sound/soc/codecs/wm8400.c
  * Copyright 2008, 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 as published by the
  *  Free Software Foundation;  either version 2 of the  License, or (at your
  *  option) any later version.
  */

 #include <linux/tty.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/regulator/consumer.h>

 #include <sound/core.h>
 #include <sound/initval.h>
 #include <sound/soc.h>

 #include "cx20442.h"


 struct cx20442_priv {
 	void *control_data;
 	struct regulator *por;
 };

 #define CX20442_PM		0x0

 #define CX20442_TELIN		0
 #define CX20442_TELOUT		1
 #define CX20442_MIC		2
 #define CX20442_SPKOUT		3
 #define CX20442_AGC		4

 static const struct snd_soc_dapm_widget cx20442_dapm_widgets[] = {
 	SND_SOC_DAPM_OUTPUT("TELOUT"),
 	SND_SOC_DAPM_OUTPUT("SPKOUT"),
 	SND_SOC_DAPM_OUTPUT("AGCOUT"),

 	SND_SOC_DAPM_MIXER("SPKOUT Mixer", SND_SOC_NOPM, 0, 0, NULL, 0),

 	SND_SOC_DAPM_PGA("TELOUT Amp", CX20442_PM, CX20442_TELOUT, 0, NULL, 0),
 	SND_SOC_DAPM_PGA("SPKOUT Amp", CX20442_PM, CX20442_SPKOUT, 0, NULL, 0),
 	SND_SOC_DAPM_PGA("SPKOUT AGC", CX20442_PM, CX20442_AGC, 0, NULL, 0),

 	SND_SOC_DAPM_DAC("DAC", "Playback", SND_SOC_NOPM, 0, 0),
 	SND_SOC_DAPM_ADC("ADC", "Capture", SND_SOC_NOPM, 0, 0),

 	SND_SOC_DAPM_MIXER("Input Mixer", SND_SOC_NOPM, 0, 0, NULL, 0),

 	SND_SOC_DAPM_MICBIAS("TELIN Bias", CX20442_PM, CX20442_TELIN, 0),
 	SND_SOC_DAPM_MICBIAS("MIC Bias", CX20442_PM, CX20442_MIC, 0),

 	SND_SOC_DAPM_PGA("MIC AGC", CX20442_PM, CX20442_AGC, 0, NULL, 0),

 	SND_SOC_DAPM_INPUT("TELIN"),
 	SND_SOC_DAPM_INPUT("MIC"),
 	SND_SOC_DAPM_INPUT("AGCIN"),
 };

 static const struct snd_soc_dapm_route cx20442_audio_map[] = {
 	{"TELOUT", NULL, "TELOUT Amp"},

 	{"SPKOUT", NULL, "SPKOUT Mixer"},
 	{"SPKOUT Mixer", NULL, "SPKOUT Amp"},

 	{"TELOUT Amp", NULL, "DAC"},
 	{"SPKOUT Amp", NULL, "DAC"},

 	{"SPKOUT Mixer", NULL, "SPKOUT AGC"},
 	{"SPKOUT AGC", NULL, "AGCIN"},

 	{"AGCOUT", NULL, "MIC AGC"},
 	{"MIC AGC", NULL, "MIC"},

 	{"MIC Bias", NULL, "MIC"},
 	{"Input Mixer", NULL, "MIC Bias"},

 	{"TELIN Bias", NULL, "TELIN"},
 	{"Input Mixer", NULL, "TELIN Bias"},

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

 static unsigned int cx20442_read_reg_cache(struct snd_soc_codec *codec,
 							unsigned int reg)
 {
 	u8 *reg_cache = codec->reg_cache;

 	if (reg >= codec->driver->reg_cache_size)
 		return -EINVAL;

 	return reg_cache[reg];
 }

 enum v253_vls {
 	V253_VLS_NONE = 0,
 	V253_VLS_T,
 	V253_VLS_L,
 	V253_VLS_LT,
 	V253_VLS_S,
 	V253_VLS_ST,
 	V253_VLS_M,
 	V253_VLS_MST,
 	V253_VLS_S1,
 	V253_VLS_S1T,
 	V253_VLS_MS1T,
 	V253_VLS_M1,
 	V253_VLS_M1ST,
 	V253_VLS_M1S1T,
 	V253_VLS_H,
 	V253_VLS_HT,
 	V253_VLS_MS,
 	V253_VLS_MS1,
 	V253_VLS_M1S,
 	V253_VLS_M1S1,
 	V253_VLS_TEST,
 };

 static int cx20442_pm_to_v253_vls(u8 value)
 {
 	switch (value & ~(1 << CX20442_AGC)) {
 	case 0:
 		return V253_VLS_T;
 	case (1 << CX20442_SPKOUT):
 	case (1 << CX20442_MIC):
 	case (1 << CX20442_SPKOUT) | (1 << CX20442_MIC):
 		return V253_VLS_M1S1;
 	case (1 << CX20442_TELOUT):
 	case (1 << CX20442_TELIN):
 	case (1 << CX20442_TELOUT) | (1 << CX20442_TELIN):
 		return V253_VLS_L;
 	case (1 << CX20442_TELOUT) | (1 << CX20442_MIC):
 		return V253_VLS_NONE;
 	}
 	return -EINVAL;
 }
 static int cx20442_pm_to_v253_vsp(u8 value)
 {
 	switch (value & ~(1 << CX20442_AGC)) {
 	case (1 << CX20442_SPKOUT):
 	case (1 << CX20442_MIC):
 	case (1 << CX20442_SPKOUT) | (1 << CX20442_MIC):
 		return (bool)(value & (1 << CX20442_AGC));
 	}
 	return (value & (1 << CX20442_AGC)) ? -EINVAL : 0;
 }

 static int cx20442_write(struct snd_soc_codec *codec, unsigned int reg,
 							unsigned int value)
 {
 	struct cx20442_priv *cx20442 = snd_soc_codec_get_drvdata(codec);
 	u8 *reg_cache = codec->reg_cache;
 	int vls, vsp, old, len;
 	char buf[18];

 	if (reg >= codec->driver->reg_cache_size)
 		return -EINVAL;

 	/* hw_write and control_data pointers required for talking to the modem
 	 * are expected to be set by the line discipline initialization code */
 	if (!codec->hw_write || !cx20442->control_data)
 		return -EIO;

 	old = reg_cache[reg];
 	reg_cache[reg] = value;

 	vls = cx20442_pm_to_v253_vls(value);
 	if (vls < 0)
 		return vls;

 	vsp = cx20442_pm_to_v253_vsp(value);
 	if (vsp < 0)
 		return vsp;

 	if ((vls == V253_VLS_T) ||
 			(vls == cx20442_pm_to_v253_vls(old))) {
 		if (vsp == cx20442_pm_to_v253_vsp(old))
 			return 0;
 		len = snprintf(buf, ARRAY_SIZE(buf), "at+vsp=%d\r", vsp);
 	} else if (vsp == cx20442_pm_to_v253_vsp(old))
 		len = snprintf(buf, ARRAY_SIZE(buf), "at+vls=%d\r", vls);
 	else
 		len = snprintf(buf, ARRAY_SIZE(buf),
 					"at+vls=%d;+vsp=%d\r", vls, vsp);

 	if (unlikely(len > (ARRAY_SIZE(buf) - 1)))
 		return -ENOMEM;

 	dev_dbg(codec->dev, "%s: %s\n", __func__, buf);
 	if (codec->hw_write(cx20442->control_data, buf, len) != len)
 		return -EIO;

 	return 0;
 }


 /*
  * Line discpline related code
  *
  * Any of the callback functions below can be used in two ways:
  * 1) registerd by a machine driver as one of line discipline operations,
  * 2) called from a machine's provided line discipline callback function
  *    in case when extra machine specific code must be run as well.
  */

 /* Modem init: echo off, digital speaker off, quiet off, voice mode */
 static const char *v253_init = "ate0m0q0+fclass=8\r";

 /* Line discipline .open() */
 static int v253_open(struct tty_struct *tty)
 {
 	int ret, len = strlen(v253_init);

 	/* Doesn't make sense without write callback */
 	if (!tty->ops->write)
 		return -EINVAL;

 	/* Won't work if no codec pointer has been passed by a card driver */
 	if (!tty->disc_data)
 		return -ENODEV;

 	if (tty->ops->write(tty, v253_init, len) != len) {
 		ret = -EIO;
 		goto err;
 	}
 	/* Actual setup will be performed after the modem responds. */
 	return 0;
 err:
 	tty->disc_data = NULL;
 	return ret;
 }

 /* Line discipline .close() */
 static void v253_close(struct tty_struct *tty)
 {
 	struct snd_soc_codec *codec = tty->disc_data;
 	struct cx20442_priv *cx20442;

 	tty->disc_data = NULL;

 	if (!codec)
 		return;

 	cx20442 = snd_soc_codec_get_drvdata(codec);

 	/* Prevent the codec driver from further accessing the modem */
 	codec->hw_write = NULL;
 	cx20442->control_data = NULL;
 	codec->component.card->pop_time = 0;
 }

 /* Line discipline .hangup() */
 static int v253_hangup(struct tty_struct *tty)
 {
 	v253_close(tty);
 	return 0;
 }

 /* Line discipline .receive_buf() */
 static void v253_receive(struct tty_struct *tty,
 				const unsigned char *cp, char *fp, int count)
 {
 	struct snd_soc_codec *codec = tty->disc_data;
 	struct cx20442_priv *cx20442;

 	if (!codec)
 		return;

 	cx20442 = snd_soc_codec_get_drvdata(codec);

 	if (!cx20442->control_data) {
 		/* First modem response, complete setup procedure */

 		/* Set up codec driver access to modem controls */
 		cx20442->control_data = tty;
 		codec->hw_write = (hw_write_t)tty->ops->write;
 		codec->component.card->pop_time = 1;
 	}
 }

 /* Line discipline .write_wakeup() */
 static void v253_wakeup(struct tty_struct *tty)
 {
 }

 struct tty_ldisc_ops v253_ops = {
 	.magic = TTY_LDISC_MAGIC,
 	.name = "cx20442",
 	.owner = THIS_MODULE,
 	.open = v253_open,
 	.close = v253_close,
 	.hangup = v253_hangup,
 	.receive_buf = v253_receive,
 	.write_wakeup = v253_wakeup,
 };
 EXPORT_SYMBOL_GPL(v253_ops);


 /*
  * Codec DAI
  */

 static struct snd_soc_dai_driver cx20442_dai = {
 	.name = "cx20442-voice",
 	.playback = {
 		.stream_name = "Playback",
 		.channels_min = 1,
 		.channels_max = 1,
 		.rates = SNDRV_PCM_RATE_8000,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
 	},
 	.capture = {
 		.stream_name = "Capture",
 		.channels_min = 1,
 		.channels_max = 1,
 		.rates = SNDRV_PCM_RATE_8000,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
 	},
 };

 static int cx20442_set_bias_level(struct snd_soc_codec *codec,
 		enum snd_soc_bias_level level)
 {
 	struct cx20442_priv *cx20442 = snd_soc_codec_get_drvdata(codec);
 	int err = 0;

 	switch (level) {
 	case SND_SOC_BIAS_PREPARE:
 		if (snd_soc_codec_get_bias_level(codec) != SND_SOC_BIAS_STANDBY)
 			break;
 		if (IS_ERR(cx20442->por))
 			err = PTR_ERR(cx20442->por);
 		else
 			err = regulator_enable(cx20442->por);
 		break;
 	case SND_SOC_BIAS_STANDBY:
 		if (snd_soc_codec_get_bias_level(codec) != SND_SOC_BIAS_PREPARE)
 			break;
 		if (IS_ERR(cx20442->por))
 			err = PTR_ERR(cx20442->por);
 		else
 			err = regulator_disable(cx20442->por);
 		break;
 	default:
 		break;
 	}

 	return err;
 }

 static int cx20442_codec_probe(struct snd_soc_codec *codec)
 {
 	struct cx20442_priv *cx20442;

 	cx20442 = kzalloc(sizeof(struct cx20442_priv), GFP_KERNEL);
 	if (cx20442 == NULL)
 		return -ENOMEM;

 	cx20442->por = regulator_get(codec->dev, "POR");
 	if (IS_ERR(cx20442->por))
 		dev_warn(codec->dev, "failed to get the regulator");
 	cx20442->control_data = NULL;

 	snd_soc_codec_set_drvdata(codec, cx20442);
 	codec->hw_write = NULL;
 	codec->component.card->pop_time = 0;

 	return 0;
 }

 /* power down chip */
 static int cx20442_codec_remove(struct snd_soc_codec *codec)
 {
 	struct cx20442_priv *cx20442 = snd_soc_codec_get_drvdata(codec);

 	if (cx20442->control_data) {
 		struct tty_struct *tty = cx20442->control_data;
 		tty_hangup(tty);
 	}

 	if (!IS_ERR(cx20442->por)) {
 		/* should be already in STANDBY, hence disabled */
 		regulator_put(cx20442->por);
 	}

 	snd_soc_codec_set_drvdata(codec, NULL);
 	kfree(cx20442);
 	return 0;
 }

 static const u8 cx20442_reg;

 static struct snd_soc_codec_driver cx20442_codec_dev = {
 	.probe = 	cx20442_codec_probe,
 	.remove = 	cx20442_codec_remove,
 	.set_bias_level = cx20442_set_bias_level,
 	.reg_cache_default = &cx20442_reg,
 	.reg_cache_size = 1,
 	.reg_word_size = sizeof(u8),
 	.read = cx20442_read_reg_cache,
 	.write = cx20442_write,
 	.dapm_widgets = cx20442_dapm_widgets,
 	.num_dapm_widgets = ARRAY_SIZE(cx20442_dapm_widgets),
 	.dapm_routes = cx20442_audio_map,
 	.num_dapm_routes = ARRAY_SIZE(cx20442_audio_map),
 };

 static int cx20442_platform_probe(struct platform_device *pdev)
 {
 	return snd_soc_register_codec(&pdev->dev,
 			&cx20442_codec_dev, &cx20442_dai, 1);
 }

 static int cx20442_platform_remove(struct platform_device *pdev)
 {
 	snd_soc_unregister_codec(&pdev->dev);
 	return 0;
 }

 static struct platform_driver cx20442_platform_driver = {
 	.driver = {
 		.name = "cx20442-codec",
 		},
 	.probe = cx20442_platform_probe,
 	.remove = cx20442_platform_remove,
 };

 module_platform_driver(cx20442_platform_driver);

 MODULE_DESCRIPTION("ASoC CX20442-11 voice modem codec driver");
 MODULE_AUTHOR("Janusz Krzysztofik");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:cx20442-codec");
	/*
	* cx20442.c -- CX20442 ALSA Soc Audio driver
	*
	* Copyright 2009 Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
	*
	* Initially based on sound/soc/codecs/wm8400.c
	* Copyright 2008, 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 as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*/

	#include <linux/tty.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/regulator/consumer.h>

	#include <sound/core.h>
	#include <sound/initval.h>
	#include <sound/soc.h>

	#include "cx20442.h"


	struct cx20442_priv {
	void *control_data;
	struct regulator *por;
	};

	#define CX20442_PM 0x0

	#define CX20442_TELIN 0
	#define CX20442_TELOUT 1
	#define CX20442_MIC 2
	#define CX20442_SPKOUT 3
	#define CX20442_AGC 4

	static const struct snd_soc_dapm_widget cx20442_dapm_widgets[] = {
	SND_SOC_DAPM_OUTPUT("TELOUT"),
	SND_SOC_DAPM_OUTPUT("SPKOUT"),
	SND_SOC_DAPM_OUTPUT("AGCOUT"),

	SND_SOC_DAPM_MIXER("SPKOUT Mixer", SND_SOC_NOPM, 0, 0, NULL, 0),

	SND_SOC_DAPM_PGA("TELOUT Amp", CX20442_PM, CX20442_TELOUT, 0, NULL, 0),
	SND_SOC_DAPM_PGA("SPKOUT Amp", CX20442_PM, CX20442_SPKOUT, 0, NULL, 0),
	SND_SOC_DAPM_PGA("SPKOUT AGC", CX20442_PM, CX20442_AGC, 0, NULL, 0),

	SND_SOC_DAPM_DAC("DAC", "Playback", SND_SOC_NOPM, 0, 0),
	SND_SOC_DAPM_ADC("ADC", "Capture", SND_SOC_NOPM, 0, 0),

	SND_SOC_DAPM_MIXER("Input Mixer", SND_SOC_NOPM, 0, 0, NULL, 0),

	SND_SOC_DAPM_MICBIAS("TELIN Bias", CX20442_PM, CX20442_TELIN, 0),
	SND_SOC_DAPM_MICBIAS("MIC Bias", CX20442_PM, CX20442_MIC, 0),

	SND_SOC_DAPM_PGA("MIC AGC", CX20442_PM, CX20442_AGC, 0, NULL, 0),

	SND_SOC_DAPM_INPUT("TELIN"),
	SND_SOC_DAPM_INPUT("MIC"),
	SND_SOC_DAPM_INPUT("AGCIN"),
	};

	static const struct snd_soc_dapm_route cx20442_audio_map[] = {
	{"TELOUT", NULL, "TELOUT Amp"},

	{"SPKOUT", NULL, "SPKOUT Mixer"},
	{"SPKOUT Mixer", NULL, "SPKOUT Amp"},

	{"TELOUT Amp", NULL, "DAC"},
	{"SPKOUT Amp", NULL, "DAC"},

	{"SPKOUT Mixer", NULL, "SPKOUT AGC"},
	{"SPKOUT AGC", NULL, "AGCIN"},

	{"AGCOUT", NULL, "MIC AGC"},
	{"MIC AGC", NULL, "MIC"},

	{"MIC Bias", NULL, "MIC"},
	{"Input Mixer", NULL, "MIC Bias"},

	{"TELIN Bias", NULL, "TELIN"},
	{"Input Mixer", NULL, "TELIN Bias"},

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

	static unsigned int cx20442_read_reg_cache(struct snd_soc_codec *codec,
	unsigned int reg)
	{
	u8 *reg_cache = codec->reg_cache;

	if (reg >= codec->driver->reg_cache_size)
	return -EINVAL;

	return reg_cache[reg];
	}

	enum v253_vls {
	V253_VLS_NONE = 0,
	V253_VLS_T,
	V253_VLS_L,
	V253_VLS_LT,
	V253_VLS_S,
	V253_VLS_ST,
	V253_VLS_M,
	V253_VLS_MST,
	V253_VLS_S1,
	V253_VLS_S1T,
	V253_VLS_MS1T,
	V253_VLS_M1,
	V253_VLS_M1ST,
	V253_VLS_M1S1T,
	V253_VLS_H,
	V253_VLS_HT,
	V253_VLS_MS,
	V253_VLS_MS1,
	V253_VLS_M1S,
	V253_VLS_M1S1,
	V253_VLS_TEST,
	};

	static int cx20442_pm_to_v253_vls(u8 value)
	{
	switch (value & ~(1 << CX20442_AGC)) {
	case 0:
	return V253_VLS_T;
	case (1 << CX20442_SPKOUT):
	case (1 << CX20442_MIC):
	case (1 << CX20442_SPKOUT) \| (1 << CX20442_MIC):
	return V253_VLS_M1S1;
	case (1 << CX20442_TELOUT):
	case (1 << CX20442_TELIN):
	case (1 << CX20442_TELOUT) \| (1 << CX20442_TELIN):
	return V253_VLS_L;
	case (1 << CX20442_TELOUT) \| (1 << CX20442_MIC):
	return V253_VLS_NONE;
	}
	return -EINVAL;
	}
	static int cx20442_pm_to_v253_vsp(u8 value)
	{
	switch (value & ~(1 << CX20442_AGC)) {
	case (1 << CX20442_SPKOUT):
	case (1 << CX20442_MIC):
	case (1 << CX20442_SPKOUT) \| (1 << CX20442_MIC):
	return (bool)(value & (1 << CX20442_AGC));
	}
	return (value & (1 << CX20442_AGC)) ? -EINVAL : 0;
	}

	static int cx20442_write(struct snd_soc_codec *codec, unsigned int reg,
	unsigned int value)
	{
	struct cx20442_priv *cx20442 = snd_soc_codec_get_drvdata(codec);
	u8 *reg_cache = codec->reg_cache;
	int vls, vsp, old, len;
	char buf[18];

	if (reg >= codec->driver->reg_cache_size)
	return -EINVAL;

	/* hw_write and control_data pointers required for talking to the modem
	* are expected to be set by the line discipline initialization code */
	if (!codec->hw_write \|\| !cx20442->control_data)
	return -EIO;

	old = reg_cache[reg];
	reg_cache[reg] = value;

	vls = cx20442_pm_to_v253_vls(value);
	if (vls < 0)
	return vls;

	vsp = cx20442_pm_to_v253_vsp(value);
	if (vsp < 0)
	return vsp;

	if ((vls == V253_VLS_T) \|\|
	(vls == cx20442_pm_to_v253_vls(old))) {
	if (vsp == cx20442_pm_to_v253_vsp(old))
	return 0;
	len = snprintf(buf, ARRAY_SIZE(buf), "at+vsp=%d\r", vsp);
	} else if (vsp == cx20442_pm_to_v253_vsp(old))
	len = snprintf(buf, ARRAY_SIZE(buf), "at+vls=%d\r", vls);
	else
	len = snprintf(buf, ARRAY_SIZE(buf),
	"at+vls=%d;+vsp=%d\r", vls, vsp);

	if (unlikely(len > (ARRAY_SIZE(buf) - 1)))
	return -ENOMEM;

	dev_dbg(codec->dev, "%s: %s\n", __func__, buf);
	if (codec->hw_write(cx20442->control_data, buf, len) != len)
	return -EIO;

	return 0;
	}


	/*
	* Line discpline related code
	*
	* Any of the callback functions below can be used in two ways:
	* 1) registerd by a machine driver as one of line discipline operations,
	* 2) called from a machine's provided line discipline callback function
	* in case when extra machine specific code must be run as well.
	*/

	/* Modem init: echo off, digital speaker off, quiet off, voice mode */
	static const char *v253_init = "ate0m0q0+fclass=8\r";

	/* Line discipline .open() */
	static int v253_open(struct tty_struct *tty)
	{
	int ret, len = strlen(v253_init);

	/* Doesn't make sense without write callback */
	if (!tty->ops->write)
	return -EINVAL;

	/* Won't work if no codec pointer has been passed by a card driver */
	if (!tty->disc_data)
	return -ENODEV;

	if (tty->ops->write(tty, v253_init, len) != len) {
	ret = -EIO;
	goto err;
	}
	/* Actual setup will be performed after the modem responds. */
	return 0;
	err:
	tty->disc_data = NULL;
	return ret;
	}

	/* Line discipline .close() */
	static void v253_close(struct tty_struct *tty)
	{
	struct snd_soc_codec *codec = tty->disc_data;
	struct cx20442_priv *cx20442;

	tty->disc_data = NULL;

	if (!codec)
	return;

	cx20442 = snd_soc_codec_get_drvdata(codec);

	/* Prevent the codec driver from further accessing the modem */
	codec->hw_write = NULL;
	cx20442->control_data = NULL;
	codec->component.card->pop_time = 0;
	}

	/* Line discipline .hangup() */
	static int v253_hangup(struct tty_struct *tty)
	{
	v253_close(tty);
	return 0;
	}

	/* Line discipline .receive_buf() */
	static void v253_receive(struct tty_struct *tty,
	const unsigned char cp, char fp, int count)
	{
	struct snd_soc_codec *codec = tty->disc_data;
	struct cx20442_priv *cx20442;

	if (!codec)
	return;

	cx20442 = snd_soc_codec_get_drvdata(codec);

	if (!cx20442->control_data) {
	/* First modem response, complete setup procedure */

	/* Set up codec driver access to modem controls */
	cx20442->control_data = tty;
	codec->hw_write = (hw_write_t)tty->ops->write;
	codec->component.card->pop_time = 1;
	}
	}

	/* Line discipline .write_wakeup() */
	static void v253_wakeup(struct tty_struct *tty)
	{
	}

	struct tty_ldisc_ops v253_ops = {
	.magic = TTY_LDISC_MAGIC,
	.name = "cx20442",
	.owner = THIS_MODULE,
	.open = v253_open,
	.close = v253_close,
	.hangup = v253_hangup,
	.receive_buf = v253_receive,
	.write_wakeup = v253_wakeup,
	};
	EXPORT_SYMBOL_GPL(v253_ops);


	/*
	* Codec DAI
	*/

	static struct snd_soc_dai_driver cx20442_dai = {
	.name = "cx20442-voice",
	.playback = {
	.stream_name = "Playback",
	.channels_min = 1,
	.channels_max = 1,
	.rates = SNDRV_PCM_RATE_8000,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,
	},
	.capture = {
	.stream_name = "Capture",
	.channels_min = 1,
	.channels_max = 1,
	.rates = SNDRV_PCM_RATE_8000,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,
	},
	};

	static int cx20442_set_bias_level(struct snd_soc_codec *codec,
	enum snd_soc_bias_level level)
	{
	struct cx20442_priv *cx20442 = snd_soc_codec_get_drvdata(codec);
	int err = 0;

	switch (level) {
	case SND_SOC_BIAS_PREPARE:
	if (snd_soc_codec_get_bias_level(codec) != SND_SOC_BIAS_STANDBY)
	break;
	if (IS_ERR(cx20442->por))
	err = PTR_ERR(cx20442->por);
	else
	err = regulator_enable(cx20442->por);
	break;
	case SND_SOC_BIAS_STANDBY:
	if (snd_soc_codec_get_bias_level(codec) != SND_SOC_BIAS_PREPARE)
	break;
	if (IS_ERR(cx20442->por))
	err = PTR_ERR(cx20442->por);
	else
	err = regulator_disable(cx20442->por);
	break;
	default:
	break;
	}

	return err;
	}

	static int cx20442_codec_probe(struct snd_soc_codec *codec)
	{
	struct cx20442_priv *cx20442;

	cx20442 = kzalloc(sizeof(struct cx20442_priv), GFP_KERNEL);
	if (cx20442 == NULL)
	return -ENOMEM;

	cx20442->por = regulator_get(codec->dev, "POR");
	if (IS_ERR(cx20442->por))
	dev_warn(codec->dev, "failed to get the regulator");
	cx20442->control_data = NULL;

	snd_soc_codec_set_drvdata(codec, cx20442);
	codec->hw_write = NULL;
	codec->component.card->pop_time = 0;

	return 0;
	}

	/* power down chip */
	static int cx20442_codec_remove(struct snd_soc_codec *codec)
	{
	struct cx20442_priv *cx20442 = snd_soc_codec_get_drvdata(codec);

	if (cx20442->control_data) {
	struct tty_struct *tty = cx20442->control_data;
	tty_hangup(tty);
	}

	if (!IS_ERR(cx20442->por)) {
	/* should be already in STANDBY, hence disabled */
	regulator_put(cx20442->por);
	}

	snd_soc_codec_set_drvdata(codec, NULL);
	kfree(cx20442);
	return 0;
	}

	static const u8 cx20442_reg;

	static struct snd_soc_codec_driver cx20442_codec_dev = {
	.probe = cx20442_codec_probe,
	.remove = cx20442_codec_remove,
	.set_bias_level = cx20442_set_bias_level,
	.reg_cache_default = &cx20442_reg,
	.reg_cache_size = 1,
	.reg_word_size = sizeof(u8),
	.read = cx20442_read_reg_cache,
	.write = cx20442_write,
	.dapm_widgets = cx20442_dapm_widgets,
	.num_dapm_widgets = ARRAY_SIZE(cx20442_dapm_widgets),
	.dapm_routes = cx20442_audio_map,
	.num_dapm_routes = ARRAY_SIZE(cx20442_audio_map),
	};

	static int cx20442_platform_probe(struct platform_device *pdev)
	{
	return snd_soc_register_codec(&pdev->dev,
	&cx20442_codec_dev, &cx20442_dai, 1);
	}

	static int cx20442_platform_remove(struct platform_device *pdev)
	{
	snd_soc_unregister_codec(&pdev->dev);
	return 0;
	}

	static struct platform_driver cx20442_platform_driver = {
	.driver = {
	.name = "cx20442-codec",
	},
	.probe = cx20442_platform_probe,
	.remove = cx20442_platform_remove,
	};

	module_platform_driver(cx20442_platform_driver);

	MODULE_DESCRIPTION("ASoC CX20442-11 voice modem codec driver");
	MODULE_AUTHOR("Janusz Krzysztofik");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:cx20442-codec");