cx20442.c

Go to the documentation of this file.

/*
 * cx20442.c  --  CX20442 ALSA Soc Audio driver
 *
 * Copyright 2009 Janusz Krzysztofik <[email protected]>
 *
 * Initially based on sound/soc/codecs/wm8400.c
 * Copyright 2008, 2009 Wolfson Microelectronics PLC.
 * Author: Mark Brown <[email protected]>
 *
 *  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->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");