lm4857.c

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/*
 * LM4857 AMP driver
 *
 * Copyright 2007 Wolfson Microelectronics PLC.
 * Author: Graeme Gregory
 *         [email protected]
 * Copyright 2011 Lars-Peter Clausen <[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/init.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>

#include <sound/core.h>
#include <sound/soc.h>
#include <sound/tlv.h>

struct lm4857 {
    struct i2c_client *i2c;
    uint8_t mode;
};

static const uint8_t lm4857_default_regs[] = {
    0x00, 0x00, 0x00, 0x00,
};

/* The register offsets in the cache array */
#define LM4857_MVOL 0
#define LM4857_LVOL 1
#define LM4857_RVOL 2
#define LM4857_CTRL 3

/* the shifts required to set these bits */
#define LM4857_3D 5
#define LM4857_WAKEUP 5
#define LM4857_EPGAIN 4

static int lm4857_write(struct snd_soc_codec *codec, unsigned int reg,
        unsigned int value)
{
    uint8_t data;
    int ret;

    ret = snd_soc_cache_write(codec, reg, value);
    if (ret < 0)
        return ret;

    data = (reg << 6) | value;
    ret = i2c_master_send(codec->control_data, &data, 1);
    if (ret != 1) {
        dev_err(codec->dev, "Failed to write register: %d\n", ret);
        return ret;
    }

    return 0;
}

static unsigned int lm4857_read(struct snd_soc_codec *codec,
        unsigned int reg)
{
    unsigned int val;
    int ret;

    ret = snd_soc_cache_read(codec, reg, &val);
    if (ret)
        return -1;

    return val;
}

static int lm4857_get_mode(struct snd_kcontrol *kcontrol,
    struct snd_ctl_elem_value *ucontrol)
{
    struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
    struct lm4857 *lm4857 = snd_soc_codec_get_drvdata(codec);

    ucontrol->value.integer.value[0] = lm4857->mode;

    return 0;
}

static int lm4857_set_mode(struct snd_kcontrol *kcontrol,
    struct snd_ctl_elem_value *ucontrol)
{
    struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
    struct lm4857 *lm4857 = snd_soc_codec_get_drvdata(codec);
    uint8_t value = ucontrol->value.integer.value[0];

    lm4857->mode = value;

    if (codec->dapm.bias_level == SND_SOC_BIAS_ON)
        snd_soc_update_bits(codec, LM4857_CTRL, 0x0F, value + 6);

    return 1;
}

static int lm4857_set_bias_level(struct snd_soc_codec *codec,
                 enum snd_soc_bias_level level)
{
    struct lm4857 *lm4857 = snd_soc_codec_get_drvdata(codec);

    switch (level) {
    case SND_SOC_BIAS_ON:
        snd_soc_update_bits(codec, LM4857_CTRL, 0x0F, lm4857->mode + 6);
        break;
    case SND_SOC_BIAS_STANDBY:
        snd_soc_update_bits(codec, LM4857_CTRL, 0x0F, 0);
        break;
    default:
        break;
    }

    codec->dapm.bias_level = level;

    return 0;
}

static const char *lm4857_mode[] = {
    "Earpiece",
    "Loudspeaker",
    "Loudspeaker + Headphone",
    "Headphone",
};

static const struct soc_enum lm4857_mode_enum =
    SOC_ENUM_SINGLE_EXT(ARRAY_SIZE(lm4857_mode), lm4857_mode);

static const struct snd_soc_dapm_widget lm4857_dapm_widgets[] = {
    SND_SOC_DAPM_INPUT("IN"),

    SND_SOC_DAPM_OUTPUT("LS"),
    SND_SOC_DAPM_OUTPUT("HP"),
    SND_SOC_DAPM_OUTPUT("EP"),
};

static const DECLARE_TLV_DB_SCALE(stereo_tlv, -4050, 150, 0);
static const DECLARE_TLV_DB_SCALE(mono_tlv, -3450, 150, 0);

static const struct snd_kcontrol_new lm4857_controls[] = {
    SOC_SINGLE_TLV("Left Playback Volume", LM4857_LVOL, 0, 31, 0,
        stereo_tlv),
    SOC_SINGLE_TLV("Right Playback Volume", LM4857_RVOL, 0, 31, 0,
        stereo_tlv),
    SOC_SINGLE_TLV("Mono Playback Volume", LM4857_MVOL, 0, 31, 0,
        mono_tlv),
    SOC_SINGLE("Spk 3D Playback Switch", LM4857_LVOL, LM4857_3D, 1, 0),
    SOC_SINGLE("HP 3D Playback Switch", LM4857_RVOL, LM4857_3D, 1, 0),
    SOC_SINGLE("Fast Wakeup Playback Switch", LM4857_CTRL,
        LM4857_WAKEUP, 1, 0),
    SOC_SINGLE("Earpiece 6dB Playback Switch", LM4857_CTRL,
        LM4857_EPGAIN, 1, 0),

    SOC_ENUM_EXT("Mode", lm4857_mode_enum,
        lm4857_get_mode, lm4857_set_mode),
};

/* There is a demux between the input signal and the output signals.
 * Currently there is no easy way to model it in ASoC and since it does not make
 * much of a difference in practice simply connect the input direclty to the
 * outputs. */
static const struct snd_soc_dapm_route lm4857_routes[] = {
    {"LS", NULL, "IN"},
    {"HP", NULL, "IN"},
    {"EP", NULL, "IN"},
};

static int lm4857_probe(struct snd_soc_codec *codec)
{
    struct lm4857 *lm4857 = snd_soc_codec_get_drvdata(codec);
    struct snd_soc_dapm_context *dapm = &codec->dapm;
    int ret;

    codec->control_data = lm4857->i2c;

    ret = snd_soc_add_codec_controls(codec, lm4857_controls,
            ARRAY_SIZE(lm4857_controls));
    if (ret)
        return ret;

    ret = snd_soc_dapm_new_controls(dapm, lm4857_dapm_widgets,
            ARRAY_SIZE(lm4857_dapm_widgets));
    if (ret)
        return ret;

    ret = snd_soc_dapm_add_routes(dapm, lm4857_routes,
            ARRAY_SIZE(lm4857_routes));
    if (ret)
        return ret;

    snd_soc_dapm_new_widgets(dapm);

    return 0;
}

static struct snd_soc_codec_driver soc_codec_dev_lm4857 = {
    .write = lm4857_write,
    .read = lm4857_read,
    .probe = lm4857_probe,
    .reg_cache_size = ARRAY_SIZE(lm4857_default_regs),
    .reg_word_size = sizeof(uint8_t),
    .reg_cache_default = lm4857_default_regs,
    .set_bias_level = lm4857_set_bias_level,
};

static int __devinit lm4857_i2c_probe(struct i2c_client *i2c,
    const struct i2c_device_id *id)
{
    struct lm4857 *lm4857;
    int ret;

    lm4857 = devm_kzalloc(&i2c->dev, sizeof(*lm4857), GFP_KERNEL);
    if (!lm4857)
        return -ENOMEM;

    i2c_set_clientdata(i2c, lm4857);

    lm4857->i2c = i2c;

    ret = snd_soc_register_codec(&i2c->dev, &soc_codec_dev_lm4857, NULL, 0);

    return ret;
}

static int __devexit lm4857_i2c_remove(struct i2c_client *i2c)
{
    snd_soc_unregister_codec(&i2c->dev);
    return 0;
}

static const struct i2c_device_id lm4857_i2c_id[] = {
    { "lm4857", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, lm4857_i2c_id);

static struct i2c_driver lm4857_i2c_driver = {
    .driver = {
        .name = "lm4857",
        .owner = THIS_MODULE,
    },
    .probe = lm4857_i2c_probe,
    .remove = __devexit_p(lm4857_i2c_remove),
    .id_table = lm4857_i2c_id,
};

module_i2c_driver(lm4857_i2c_driver);

MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>");
MODULE_DESCRIPTION("LM4857 amplifier driver");
MODULE_LICENSE("GPL");