/*
   * 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
  ", __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->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->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 (codec->dapm.bias_level != 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 (codec->dapm.bias_level != SND_SOC_BIAS_PREPARE)
  			break;
  		if (IS_ERR(cx20442->por))
  			err = PTR_ERR(cx20442->por);
  		else
  			err = regulator_disable(cx20442->por);
  		break;
  	default:
  		break;
  	}
  	if (!err)
  		codec->dapm.bias_level = level;
  
  	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->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 __exit 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",
  		.owner = THIS_MODULE,
  		},
  	.probe = cx20442_platform_probe,
  	.remove = __exit_p(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");