/*
 * 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 {
        struct tty_struct *tty;
        struct regulator *por;
        u8 reg_cache;
};

#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_component *component,
                                           unsigned int reg)
{
        struct cx20442_priv *cx20442 = snd_soc_component_get_drvdata(component);

        if (reg >= 1)
                return -EINVAL;

        return cx20442->reg_cache;
}

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_component *component, unsigned int reg,
                                                        unsigned int value)
{
        struct cx20442_priv *cx20442 = snd_soc_component_get_drvdata(component);
        int vls, vsp, old, len;
        char buf[18];

        if (reg >= 1)
                return -EINVAL;

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

        old = cx20442->reg_cache;
        cx20442->reg_cache = 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(component->dev, "%s: %s\n", __func__, buf);
        if (cx20442->tty->ops->write(cx20442->tty, 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;

        tty->receive_room = 16;
        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_component *component = tty->disc_data;
        struct cx20442_priv *cx20442;

        tty->disc_data = NULL;

        if (!component)
                return;

        cx20442 = snd_soc_component_get_drvdata(component);

        /* Prevent the codec driver from further accessing the modem */
        cx20442->tty = NULL;
        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_component *component = tty->disc_data;
        struct cx20442_priv *cx20442;

        if (!component)
                return;

        cx20442 = snd_soc_component_get_drvdata(component);

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

                /* Set up codec driver access to modem controls */
                cx20442->tty = tty;
                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_component *component,
                enum snd_soc_bias_level level)
{
        struct cx20442_priv *cx20442 = snd_soc_component_get_drvdata(component);
        int err = 0;

        switch (level) {
        case SND_SOC_BIAS_PREPARE:
                if (snd_soc_component_get_bias_level(component) != 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_component_get_bias_level(component) != 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_component_probe(struct snd_soc_component *component)
{
        struct cx20442_priv *cx20442;

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

        cx20442->por = regulator_get(component->dev, "POR");
        if (IS_ERR(cx20442->por)) {
                int err = PTR_ERR(cx20442->por);

                dev_warn(component->dev, "failed to get POR supply (%d)", err);
                /*
                 * When running on a non-dt platform and requested regulator
                 * is not available, regulator_get() never returns
                 * -EPROBE_DEFER as it is not able to justify if the regulator
                 * may still appear later.  On the other hand, the board can
                 * still set full constraints flag at late_initcall in order
                 * to instruct regulator_get() to return a dummy one if
                 * sufficient.  Hence, if we get -ENODEV here, let's convert
                 * it to -EPROBE_DEFER and wait for the board to decide or
                 * let Deferred Probe infrastructure handle this error.
                 */
                if (err == -ENODEV)
                        err = -EPROBE_DEFER;
                kfree(cx20442);
                return err;
        }

        cx20442->tty = NULL;

        snd_soc_component_set_drvdata(component, cx20442);
        component->card->pop_time = 0;

        return 0;
}

/* power down chip */
static void cx20442_component_remove(struct snd_soc_component *component)
{
        struct cx20442_priv *cx20442 = snd_soc_component_get_drvdata(component);

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

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

        snd_soc_component_set_drvdata(component, NULL);
        kfree(cx20442);
}

static const struct snd_soc_component_driver cx20442_component_dev = {
        .probe                  = cx20442_component_probe,
        .remove                 = cx20442_component_remove,
        .set_bias_level         = cx20442_set_bias_level,
        .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),
        .idle_bias_on           = 1,
        .use_pmdown_time        = 1,
        .endianness             = 1,
        .non_legacy_dai_naming  = 1,
};

static int cx20442_platform_probe(struct platform_device *pdev)
{
        return devm_snd_soc_register_component(&pdev->dev,
                        &cx20442_component_dev, &cx20442_dai, 1);
}

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

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");