/*
   * ams-delta.c  --  SoC audio for Amstrad E3 (Delta) videophone
   *
   * Copyright (C) 2009 Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
   *
   * Initially based on sound/soc/omap/osk5912.x
   * Copyright (C) 2008 Mistral Solutions
   *
   * 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.
   *
   * This program is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
   * 02110-1301 USA
   *
   */
  
  #include <linux/gpio.h>
  #include <linux/spinlock.h>
  #include <linux/tty.h>
  #include <linux/module.h>
  
  #include <sound/soc.h>
  #include <sound/jack.h>
  
  #include <asm/mach-types.h>
  
  #include <mach/board-ams-delta.h>
  #include <linux/platform_data/asoc-ti-mcbsp.h>
  
  #include "omap-mcbsp.h"
  #include "../codecs/cx20442.h"
  
  
  /* Board specific DAPM widgets */
  static const struct snd_soc_dapm_widget ams_delta_dapm_widgets[] = {
  	/* Handset */
  	SND_SOC_DAPM_MIC("Mouthpiece", NULL),
  	SND_SOC_DAPM_HP("Earpiece", NULL),
  	/* Handsfree/Speakerphone */
  	SND_SOC_DAPM_MIC("Microphone", NULL),
  	SND_SOC_DAPM_SPK("Speaker", NULL),
  };
  
  /* How they are connected to codec pins */
  static const struct snd_soc_dapm_route ams_delta_audio_map[] = {
  	{"TELIN", NULL, "Mouthpiece"},
  	{"Earpiece", NULL, "TELOUT"},
  
  	{"MIC", NULL, "Microphone"},
  	{"Speaker", NULL, "SPKOUT"},
  };
  
  /*
   * Controls, functional after the modem line discipline is activated.
   */
  
  /* Virtual switch: audio input/output constellations */
  static const char *ams_delta_audio_mode[] =
  	{"Mixed", "Handset", "Handsfree", "Speakerphone"};
  
  /* Selection <-> pin translation */
  #define AMS_DELTA_MOUTHPIECE	0
  #define AMS_DELTA_EARPIECE	1
  #define AMS_DELTA_MICROPHONE	2
  #define AMS_DELTA_SPEAKER	3
  #define AMS_DELTA_AGC		4
  
  #define AMS_DELTA_MIXED		((1 << AMS_DELTA_EARPIECE) | \
  						(1 << AMS_DELTA_MICROPHONE))
  #define AMS_DELTA_HANDSET	((1 << AMS_DELTA_MOUTHPIECE) | \
  						(1 << AMS_DELTA_EARPIECE))
  #define AMS_DELTA_HANDSFREE	((1 << AMS_DELTA_MICROPHONE) | \
  						(1 << AMS_DELTA_SPEAKER))
  #define AMS_DELTA_SPEAKERPHONE	(AMS_DELTA_HANDSFREE | (1 << AMS_DELTA_AGC))
  
  static const unsigned short ams_delta_audio_mode_pins[] = {
  	AMS_DELTA_MIXED,
  	AMS_DELTA_HANDSET,
  	AMS_DELTA_HANDSFREE,
  	AMS_DELTA_SPEAKERPHONE,
  };
  
  static unsigned short ams_delta_audio_agc;
  
  static int ams_delta_set_audio_mode(struct snd_kcontrol *kcontrol,
  					struct snd_ctl_elem_value *ucontrol)
  {
  	struct snd_soc_codec *codec =  snd_kcontrol_chip(kcontrol);
  	struct snd_soc_dapm_context *dapm = &codec->dapm;
  	struct soc_enum *control = (struct soc_enum *)kcontrol->private_value;
  	unsigned short pins;
  	int pin, changed = 0;
  
  	/* Refuse any mode changes if we are not able to control the codec. */
  	if (!codec->hw_write)
  		return -EUNATCH;
  
  	if (ucontrol->value.enumerated.item[0] >= control->max)
  		return -EINVAL;
  
  	mutex_lock(&codec->mutex);
  
  	/* Translate selection to bitmap */
  	pins = ams_delta_audio_mode_pins[ucontrol->value.enumerated.item[0]];
  
  	/* Setup pins after corresponding bits if changed */
  	pin = !!(pins & (1 << AMS_DELTA_MOUTHPIECE));
  	if (pin != snd_soc_dapm_get_pin_status(dapm, "Mouthpiece")) {
  		changed = 1;
  		if (pin)
  			snd_soc_dapm_enable_pin(dapm, "Mouthpiece");
  		else
  			snd_soc_dapm_disable_pin(dapm, "Mouthpiece");
  	}
  	pin = !!(pins & (1 << AMS_DELTA_EARPIECE));
  	if (pin != snd_soc_dapm_get_pin_status(dapm, "Earpiece")) {
  		changed = 1;
  		if (pin)
  			snd_soc_dapm_enable_pin(dapm, "Earpiece");
  		else
  			snd_soc_dapm_disable_pin(dapm, "Earpiece");
  	}
  	pin = !!(pins & (1 << AMS_DELTA_MICROPHONE));
  	if (pin != snd_soc_dapm_get_pin_status(dapm, "Microphone")) {
  		changed = 1;
  		if (pin)
  			snd_soc_dapm_enable_pin(dapm, "Microphone");
  		else
  			snd_soc_dapm_disable_pin(dapm, "Microphone");
  	}
  	pin = !!(pins & (1 << AMS_DELTA_SPEAKER));
  	if (pin != snd_soc_dapm_get_pin_status(dapm, "Speaker")) {
  		changed = 1;
  		if (pin)
  			snd_soc_dapm_enable_pin(dapm, "Speaker");
  		else
  			snd_soc_dapm_disable_pin(dapm, "Speaker");
  	}
  	pin = !!(pins & (1 << AMS_DELTA_AGC));
  	if (pin != ams_delta_audio_agc) {
  		ams_delta_audio_agc = pin;
  		changed = 1;
  		if (pin)
  			snd_soc_dapm_enable_pin(dapm, "AGCIN");
  		else
  			snd_soc_dapm_disable_pin(dapm, "AGCIN");
  	}
  	if (changed)
  		snd_soc_dapm_sync(dapm);
  
  	mutex_unlock(&codec->mutex);
  
  	return changed;
  }
  
  static int ams_delta_get_audio_mode(struct snd_kcontrol *kcontrol,
  					struct snd_ctl_elem_value *ucontrol)
  {
  	struct snd_soc_codec *codec =  snd_kcontrol_chip(kcontrol);
  	struct snd_soc_dapm_context *dapm = &codec->dapm;
  	unsigned short pins, mode;
  
  	pins = ((snd_soc_dapm_get_pin_status(dapm, "Mouthpiece") <<
  							AMS_DELTA_MOUTHPIECE) |
  			(snd_soc_dapm_get_pin_status(dapm, "Earpiece") <<
  							AMS_DELTA_EARPIECE));
  	if (pins)
  		pins |= (snd_soc_dapm_get_pin_status(dapm, "Microphone") <<
  							AMS_DELTA_MICROPHONE);
  	else
  		pins = ((snd_soc_dapm_get_pin_status(dapm, "Microphone") <<
  							AMS_DELTA_MICROPHONE) |
  			(snd_soc_dapm_get_pin_status(dapm, "Speaker") <<
  							AMS_DELTA_SPEAKER) |
  			(ams_delta_audio_agc << AMS_DELTA_AGC));
  
  	for (mode = 0; mode < ARRAY_SIZE(ams_delta_audio_mode); mode++)
  		if (pins == ams_delta_audio_mode_pins[mode])
  			break;
  
  	if (mode >= ARRAY_SIZE(ams_delta_audio_mode))
  		return -EINVAL;
  
  	ucontrol->value.enumerated.item[0] = mode;
  
  	return 0;
  }
  
  static const struct soc_enum ams_delta_audio_enum[] = {
  	SOC_ENUM_SINGLE_EXT(ARRAY_SIZE(ams_delta_audio_mode),
  						ams_delta_audio_mode),
  };
  
  static const struct snd_kcontrol_new ams_delta_audio_controls[] = {
  	SOC_ENUM_EXT("Audio Mode", ams_delta_audio_enum[0],
  			ams_delta_get_audio_mode, ams_delta_set_audio_mode),
  };
  
  /* Hook switch */
  static struct snd_soc_jack ams_delta_hook_switch;
  static struct snd_soc_jack_gpio ams_delta_hook_switch_gpios[] = {
  	{
  		.gpio = 4,
  		.name = "hook_switch",
  		.report = SND_JACK_HEADSET,
  		.invert = 1,
  		.debounce_time = 150,
  	}
  };
  
  /* After we are able to control the codec over the modem,
   * the hook switch can be used for dynamic DAPM reconfiguration. */
  static struct snd_soc_jack_pin ams_delta_hook_switch_pins[] = {
  	/* Handset */
  	{
  		.pin = "Mouthpiece",
  		.mask = SND_JACK_MICROPHONE,
  	},
  	{
  		.pin = "Earpiece",
  		.mask = SND_JACK_HEADPHONE,
  	},
  	/* Handsfree */
  	{
  		.pin = "Microphone",
  		.mask = SND_JACK_MICROPHONE,
  		.invert = 1,
  	},
  	{
  		.pin = "Speaker",
  		.mask = SND_JACK_HEADPHONE,
  		.invert = 1,
  	},
  };
  
  
  /*
   * Modem line discipline, required for making above controls functional.
   * Activated from userspace with ldattach, possibly invoked from udev rule.
   */
  
  /* To actually apply any modem controlled configuration changes to the codec,
   * we must connect codec DAI pins to the modem for a moment.  Be careful not
   * to interfere with our digital mute function that shares the same hardware. */
  static struct timer_list cx81801_timer;
  static bool cx81801_cmd_pending;
  static bool ams_delta_muted;
  static DEFINE_SPINLOCK(ams_delta_lock);
  
  static void cx81801_timeout(unsigned long data)
  {
  	int muted;
  
  	spin_lock(&ams_delta_lock);
  	cx81801_cmd_pending = 0;
  	muted = ams_delta_muted;
  	spin_unlock(&ams_delta_lock);
  
  	/* Reconnect the codec DAI back from the modem to the CPU DAI
  	 * only if digital mute still off */
  	if (!muted)
  		ams_delta_latch2_write(AMS_DELTA_LATCH2_MODEM_CODEC, 0);
  }
  
  /*
   * Used for passing a codec structure pointer
   * from the board initialization code to the tty line discipline.
   */
  static struct snd_soc_codec *cx20442_codec;
  
  /* Line discipline .open() */
  static int cx81801_open(struct tty_struct *tty)
  {
  	int ret;
  
  	if (!cx20442_codec)
  		return -ENODEV;
  
  	/*
  	 * Pass the codec structure pointer for use by other ldisc callbacks,
  	 * both the card and the codec specific parts.
  	 */
  	tty->disc_data = cx20442_codec;
  
  	ret = v253_ops.open(tty);
  
  	if (ret < 0)
  		tty->disc_data = NULL;
  
  	return ret;
  }
  
  /* Line discipline .close() */
  static void cx81801_close(struct tty_struct *tty)
  {
  	struct snd_soc_codec *codec = tty->disc_data;
  	struct snd_soc_dapm_context *dapm = &codec->dapm;
  
  	del_timer_sync(&cx81801_timer);
  
  	/* Prevent the hook switch from further changing the DAPM pins */
  	INIT_LIST_HEAD(&ams_delta_hook_switch.pins);
  
  	if (!codec)
  		return;
  
  	v253_ops.close(tty);
  
  	/* Revert back to default audio input/output constellation */
  	snd_soc_dapm_disable_pin(dapm, "Mouthpiece");
  	snd_soc_dapm_enable_pin(dapm, "Earpiece");
  	snd_soc_dapm_enable_pin(dapm, "Microphone");
  	snd_soc_dapm_disable_pin(dapm, "Speaker");
  	snd_soc_dapm_disable_pin(dapm, "AGCIN");
  	snd_soc_dapm_sync(dapm);
  }
  
  /* Line discipline .hangup() */
  static int cx81801_hangup(struct tty_struct *tty)
  {
  	cx81801_close(tty);
  	return 0;
  }
  
  /* Line discipline .receive_buf() */
  static void cx81801_receive(struct tty_struct *tty,
  				const unsigned char *cp, char *fp, int count)
  {
  	struct snd_soc_codec *codec = tty->disc_data;
  	const unsigned char *c;
  	int apply, ret;
  
  	if (!codec)
  		return;
  
  	if (!codec->hw_write) {
  		/* First modem response, complete setup procedure */
  
  		/* Initialize timer used for config pulse generation */
  		setup_timer(&cx81801_timer, cx81801_timeout, 0);
  
  		v253_ops.receive_buf(tty, cp, fp, count);
  
  		/* Link hook switch to DAPM pins */
  		ret = snd_soc_jack_add_pins(&ams_delta_hook_switch,
  					ARRAY_SIZE(ams_delta_hook_switch_pins),
  					ams_delta_hook_switch_pins);
  		if (ret)
  			dev_warn(codec->dev,
  				"Failed to link hook switch to DAPM pins, "
  				"will continue with hook switch unlinked.
  ");
  
  		return;
  	}
  
  	v253_ops.receive_buf(tty, cp, fp, count);
  
  	for (c = &cp[count - 1]; c >= cp; c--) {
  		if (*c != '\r')
  			continue;
  		/* Complete modem response received, apply config to codec */
  
  		spin_lock_bh(&ams_delta_lock);
  		mod_timer(&cx81801_timer, jiffies + msecs_to_jiffies(150));
  		apply = !ams_delta_muted && !cx81801_cmd_pending;
  		cx81801_cmd_pending = 1;
  		spin_unlock_bh(&ams_delta_lock);
  
  		/* Apply config pulse by connecting the codec to the modem
  		 * if not already done */
  		if (apply)
  			ams_delta_latch2_write(AMS_DELTA_LATCH2_MODEM_CODEC,
  						AMS_DELTA_LATCH2_MODEM_CODEC);
  		break;
  	}
  }
  
  /* Line discipline .write_wakeup() */
  static void cx81801_wakeup(struct tty_struct *tty)
  {
  	v253_ops.write_wakeup(tty);
  }
  
  static struct tty_ldisc_ops cx81801_ops = {
  	.magic = TTY_LDISC_MAGIC,
  	.name = "cx81801",
  	.owner = THIS_MODULE,
  	.open = cx81801_open,
  	.close = cx81801_close,
  	.hangup = cx81801_hangup,
  	.receive_buf = cx81801_receive,
  	.write_wakeup = cx81801_wakeup,
  };
  
  
  /*
   * Even if not very useful, the sound card can still work without any of the
   * above functonality activated.  You can still control its audio input/output
   * constellation and speakerphone gain from userspace by issuing AT commands
   * over the modem port.
   */
  
  static int ams_delta_hw_params(struct snd_pcm_substream *substream,
  			 struct snd_pcm_hw_params *params)
  {
  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
  
  	/* Set cpu DAI configuration */
  	return snd_soc_dai_set_fmt(rtd->cpu_dai,
  				   SND_SOC_DAIFMT_DSP_A |
  				   SND_SOC_DAIFMT_NB_NF |
  				   SND_SOC_DAIFMT_CBM_CFM);
  }
  
  static struct snd_soc_ops ams_delta_ops = {
  	.hw_params = ams_delta_hw_params,
  };
  
  
  /* Digital mute implemented using modem/CPU multiplexer.
   * Shares hardware with codec config pulse generation */
  static bool ams_delta_muted = 1;
  
  static int ams_delta_digital_mute(struct snd_soc_dai *dai, int mute)
  {
  	int apply;
  
  	if (ams_delta_muted == mute)
  		return 0;
  
  	spin_lock_bh(&ams_delta_lock);
  	ams_delta_muted = mute;
  	apply = !cx81801_cmd_pending;
  	spin_unlock_bh(&ams_delta_lock);
  
  	if (apply)
  		ams_delta_latch2_write(AMS_DELTA_LATCH2_MODEM_CODEC,
  				mute ? AMS_DELTA_LATCH2_MODEM_CODEC : 0);
  	return 0;
  }
  
  /* Our codec DAI probably doesn't have its own .ops structure */
  static const struct snd_soc_dai_ops ams_delta_dai_ops = {
  	.digital_mute = ams_delta_digital_mute,
  };
  
  /* Will be used if the codec ever has its own digital_mute function */
  static int ams_delta_startup(struct snd_pcm_substream *substream)
  {
  	return ams_delta_digital_mute(NULL, 0);
  }
  
  static void ams_delta_shutdown(struct snd_pcm_substream *substream)
  {
  	ams_delta_digital_mute(NULL, 1);
  }
  
  
  /*
   * Card initialization
   */
  
  static int ams_delta_cx20442_init(struct snd_soc_pcm_runtime *rtd)
  {
  	struct snd_soc_codec *codec = rtd->codec;
  	struct snd_soc_dapm_context *dapm = &codec->dapm;
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  	struct snd_soc_card *card = rtd->card;
  	int ret;
  	/* Codec is ready, now add/activate board specific controls */
  
  	/* Store a pointer to the codec structure for tty ldisc use */
  	cx20442_codec = codec;
  
  	/* Set up digital mute if not provided by the codec */
  	if (!codec_dai->driver->ops) {
  		codec_dai->driver->ops = &ams_delta_dai_ops;
  	} else {
  		ams_delta_ops.startup = ams_delta_startup;
  		ams_delta_ops.shutdown = ams_delta_shutdown;
  	}
  
  	/* Add hook switch - can be used to control the codec from userspace
  	 * even if line discipline fails */
  	ret = snd_soc_jack_new(rtd->codec, "hook_switch",
  				SND_JACK_HEADSET, &ams_delta_hook_switch);
  	if (ret)
  		dev_warn(card->dev,
  				"Failed to allocate resources for hook switch, "
  				"will continue without one.
  ");
  	else {
  		ret = snd_soc_jack_add_gpios(&ams_delta_hook_switch,
  					ARRAY_SIZE(ams_delta_hook_switch_gpios),
  					ams_delta_hook_switch_gpios);
  		if (ret)
  			dev_warn(card->dev,
  				"Failed to set up hook switch GPIO line, "
  				"will continue with hook switch inactive.
  ");
  	}
  
  	/* Register optional line discipline for over the modem control */
  	ret = tty_register_ldisc(N_V253, &cx81801_ops);
  	if (ret) {
  		dev_warn(card->dev,
  				"Failed to register line discipline, "
  				"will continue without any controls.
  ");
  		return 0;
  	}
  
  	/* Add board specific DAPM widgets and routes */
  	ret = snd_soc_dapm_new_controls(dapm, ams_delta_dapm_widgets,
  					ARRAY_SIZE(ams_delta_dapm_widgets));
  	if (ret) {
  		dev_warn(card->dev,
  				"Failed to register DAPM controls, "
  				"will continue without any.
  ");
  		return 0;
  	}
  
  	ret = snd_soc_dapm_add_routes(dapm, ams_delta_audio_map,
  					ARRAY_SIZE(ams_delta_audio_map));
  	if (ret) {
  		dev_warn(card->dev,
  				"Failed to set up DAPM routes, "
  				"will continue with codec default map.
  ");
  		return 0;
  	}
  
  	/* Set up initial pin constellation */
  	snd_soc_dapm_disable_pin(dapm, "Mouthpiece");
  	snd_soc_dapm_enable_pin(dapm, "Earpiece");
  	snd_soc_dapm_enable_pin(dapm, "Microphone");
  	snd_soc_dapm_disable_pin(dapm, "Speaker");
  	snd_soc_dapm_disable_pin(dapm, "AGCIN");
  	snd_soc_dapm_disable_pin(dapm, "AGCOUT");
  
  	/* Add virtual switch */
  	ret = snd_soc_add_codec_controls(codec, ams_delta_audio_controls,
  					ARRAY_SIZE(ams_delta_audio_controls));
  	if (ret)
  		dev_warn(card->dev,
  				"Failed to register audio mode control, "
  				"will continue without it.
  ");
  
  	return 0;
  }
  
  /* DAI glue - connects codec <--> CPU */
  static struct snd_soc_dai_link ams_delta_dai_link = {
  	.name = "CX20442",
  	.stream_name = "CX20442",
  	.cpu_dai_name = "omap-mcbsp.1",
  	.codec_dai_name = "cx20442-voice",
  	.init = ams_delta_cx20442_init,
  	.platform_name = "omap-pcm-audio",
  	.codec_name = "cx20442-codec",
  	.ops = &ams_delta_ops,
  };
  
  /* Audio card driver */
  static struct snd_soc_card ams_delta_audio_card = {
  	.name = "AMS_DELTA",
  	.owner = THIS_MODULE,
  	.dai_link = &ams_delta_dai_link,
  	.num_links = 1,
  };
  
  /* Module init/exit */
  static int ams_delta_probe(struct platform_device *pdev)
  {
  	struct snd_soc_card *card = &ams_delta_audio_card;
  	int ret;
  
  	card->dev = &pdev->dev;
  
  	ret = snd_soc_register_card(card);
  	if (ret) {
  		dev_err(&pdev->dev, "snd_soc_register_card failed (%d)
  ", ret);
  		card->dev = NULL;
  		return ret;
  	}
  	return 0;
  }
  
  static int ams_delta_remove(struct platform_device *pdev)
  {
  	struct snd_soc_card *card = platform_get_drvdata(pdev);
  
  	if (tty_unregister_ldisc(N_V253) != 0)
  		dev_warn(&pdev->dev,
  			"failed to unregister V253 line discipline
  ");
  
  	snd_soc_jack_free_gpios(&ams_delta_hook_switch,
  			ARRAY_SIZE(ams_delta_hook_switch_gpios),
  			ams_delta_hook_switch_gpios);
  
  	snd_soc_unregister_card(card);
  	card->dev = NULL;
  	return 0;
  }
  
  #define DRV_NAME "ams-delta-audio"
  
  static struct platform_driver ams_delta_driver = {
  	.driver = {
  		.name = DRV_NAME,
  		.owner = THIS_MODULE,
  	},
  	.probe = ams_delta_probe,
  	.remove = ams_delta_remove,
  };
  
  module_platform_driver(ams_delta_driver);
  
  MODULE_AUTHOR("Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>");
  MODULE_DESCRIPTION("ALSA SoC driver for Amstrad E3 (Delta) videophone");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:" DRV_NAME);