ams-delta.c

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/*
 * ams-delta.c  --  SoC audio for Amstrad E3 (Delta) videophone
 *
 * Copyright (C) 2009 Janusz Krzysztofik <[email protected]>
 *
 * 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 "omap-pcm.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.\n");

        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.\n");
    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.\n");
    }

    /* 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.\n");
        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.\n");
        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.\n");
        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.\n");

    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 __devinit 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)\n", ret);
        card->dev = NULL;
        return ret;
    }
    return 0;
}

static int __devexit 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\n");

    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 = __devexit_p(ams_delta_remove),
};

module_platform_driver(ams_delta_driver);

MODULE_AUTHOR("Janusz Krzysztofik <[email protected]>");
MODULE_DESCRIPTION("ALSA SoC driver for Amstrad E3 (Delta) videophone");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);