ak4104.c

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/*
 * AK4104 ALSA SoC (ASoC) driver
 *
 * Copyright (c) 2009 Daniel Mack <[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/module.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/soc.h>
#include <sound/initval.h>
#include <linux/spi/spi.h>
#include <sound/asoundef.h>

/* AK4104 registers addresses */
#define AK4104_REG_CONTROL1     0x00
#define AK4104_REG_RESERVED     0x01
#define AK4104_REG_CONTROL2     0x02
#define AK4104_REG_TX           0x03
#define AK4104_REG_CHN_STATUS(x)    ((x) + 0x04)
#define AK4104_NUM_REGS         10

#define AK4104_REG_MASK         0x1f
#define AK4104_READ         0xc0
#define AK4104_WRITE            0xe0
#define AK4104_RESERVED_VAL     0x5b

/* Bit masks for AK4104 registers */
#define AK4104_CONTROL1_RSTN        (1 << 0)
#define AK4104_CONTROL1_PW      (1 << 1)
#define AK4104_CONTROL1_DIF0        (1 << 2)
#define AK4104_CONTROL1_DIF1        (1 << 3)

#define AK4104_CONTROL2_SEL0        (1 << 0)
#define AK4104_CONTROL2_SEL1        (1 << 1)
#define AK4104_CONTROL2_MODE        (1 << 2)

#define AK4104_TX_TXE           (1 << 0)
#define AK4104_TX_V         (1 << 1)

#define DRV_NAME "ak4104-codec"

struct ak4104_private {
    struct regmap *regmap;
};

static int ak4104_set_dai_fmt(struct snd_soc_dai *codec_dai,
                  unsigned int format)
{
    struct snd_soc_codec *codec = codec_dai->codec;
    int val = 0;
    int ret;

    /* set DAI format */
    switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
    case SND_SOC_DAIFMT_RIGHT_J:
        break;
    case SND_SOC_DAIFMT_LEFT_J:
        val |= AK4104_CONTROL1_DIF0;
        break;
    case SND_SOC_DAIFMT_I2S:
        val |= AK4104_CONTROL1_DIF0 | AK4104_CONTROL1_DIF1;
        break;
    default:
        dev_err(codec->dev, "invalid dai format\n");
        return -EINVAL;
    }

    /* This device can only be slave */
    if ((format & SND_SOC_DAIFMT_MASTER_MASK) != SND_SOC_DAIFMT_CBS_CFS)
        return -EINVAL;

    ret = snd_soc_update_bits(codec, AK4104_REG_CONTROL1,
                  AK4104_CONTROL1_DIF0 | AK4104_CONTROL1_DIF1,
                  val);
    if (ret < 0)
        return ret;

    return 0;
}

static int ak4104_hw_params(struct snd_pcm_substream *substream,
                struct snd_pcm_hw_params *params,
                struct snd_soc_dai *dai)
{
    struct snd_soc_codec *codec = dai->codec;
    int val = 0;

    /* set the IEC958 bits: consumer mode, no copyright bit */
    val |= IEC958_AES0_CON_NOT_COPYRIGHT;
    snd_soc_write(codec, AK4104_REG_CHN_STATUS(0), val);

    val = 0;

    switch (params_rate(params)) {
    case 44100:
        val |= IEC958_AES3_CON_FS_44100;
        break;
    case 48000:
        val |= IEC958_AES3_CON_FS_48000;
        break;
    case 32000:
        val |= IEC958_AES3_CON_FS_32000;
        break;
    default:
        dev_err(codec->dev, "unsupported sampling rate\n");
        return -EINVAL;
    }

    return snd_soc_write(codec, AK4104_REG_CHN_STATUS(3), val);
}

static const struct snd_soc_dai_ops ak4101_dai_ops = {
    .hw_params = ak4104_hw_params,
    .set_fmt = ak4104_set_dai_fmt,
};

static struct snd_soc_dai_driver ak4104_dai = {
    .name = "ak4104-hifi",
    .playback = {
        .stream_name = "Playback",
        .channels_min = 2,
        .channels_max = 2,
        .rates = SNDRV_PCM_RATE_8000_192000,
        .formats = SNDRV_PCM_FMTBIT_S16_LE  |
               SNDRV_PCM_FMTBIT_S24_3LE |
               SNDRV_PCM_FMTBIT_S24_LE
    },
    .ops = &ak4101_dai_ops,
};

static int ak4104_probe(struct snd_soc_codec *codec)
{
    struct ak4104_private *ak4104 = snd_soc_codec_get_drvdata(codec);
    int ret;

    codec->control_data = ak4104->regmap;
    ret = snd_soc_codec_set_cache_io(codec, 8, 8, SND_SOC_REGMAP);
    if (ret != 0)
        return ret;

    /* set power-up and non-reset bits */
    ret = snd_soc_update_bits(codec, AK4104_REG_CONTROL1,
                  AK4104_CONTROL1_PW | AK4104_CONTROL1_RSTN,
                  AK4104_CONTROL1_PW | AK4104_CONTROL1_RSTN);
    if (ret < 0)
        return ret;

    /* enable transmitter */
    ret = snd_soc_update_bits(codec, AK4104_REG_TX,
                  AK4104_TX_TXE, AK4104_TX_TXE);
    if (ret < 0)
        return ret;

    return 0;
}

static int ak4104_remove(struct snd_soc_codec *codec)
{
    snd_soc_update_bits(codec, AK4104_REG_CONTROL1,
                AK4104_CONTROL1_PW | AK4104_CONTROL1_RSTN, 0);

    return 0;
}

static struct snd_soc_codec_driver soc_codec_device_ak4104 = {
    .probe =    ak4104_probe,
    .remove =   ak4104_remove,
};

static const struct regmap_config ak4104_regmap = {
    .reg_bits = 8,
    .val_bits = 8,

    .max_register = AK4104_NUM_REGS - 1,
    .read_flag_mask = AK4104_READ,
    .write_flag_mask = AK4104_WRITE,

    .cache_type = REGCACHE_RBTREE,
};

static int ak4104_spi_probe(struct spi_device *spi)
{
    struct ak4104_private *ak4104;
    unsigned int val;
    int ret;

    spi->bits_per_word = 8;
    spi->mode = SPI_MODE_0;
    ret = spi_setup(spi);
    if (ret < 0)
        return ret;

    ak4104 = devm_kzalloc(&spi->dev, sizeof(struct ak4104_private),
                  GFP_KERNEL);
    if (ak4104 == NULL)
        return -ENOMEM;

    ak4104->regmap = regmap_init_spi(spi, &ak4104_regmap);
    if (IS_ERR(ak4104->regmap)) {
        ret = PTR_ERR(ak4104->regmap);
        return ret;
    }

    /* read the 'reserved' register - according to the datasheet, it
     * should contain 0x5b. Not a good way to verify the presence of
     * the device, but there is no hardware ID register. */
    ret = regmap_read(ak4104->regmap, AK4104_REG_RESERVED, &val);
    if (ret != 0)
        goto err;
    if (val != AK4104_RESERVED_VAL) {
        ret = -ENODEV;
        goto err;
    }

    spi_set_drvdata(spi, ak4104);

    ret = snd_soc_register_codec(&spi->dev,
            &soc_codec_device_ak4104, &ak4104_dai, 1);
    if (ret != 0)
        goto err;

    return 0;

err:
    regmap_exit(ak4104->regmap);
    return ret;
}

static int __devexit ak4104_spi_remove(struct spi_device *spi)
{
    struct ak4104_private *ak4101 = spi_get_drvdata(spi);
    regmap_exit(ak4101->regmap);
    snd_soc_unregister_codec(&spi->dev);
    return 0;
}

static struct spi_driver ak4104_spi_driver = {
    .driver  = {
        .name   = DRV_NAME,
        .owner  = THIS_MODULE,
    },
    .probe  = ak4104_spi_probe,
    .remove = __devexit_p(ak4104_spi_remove),
};

module_spi_driver(ak4104_spi_driver);

MODULE_AUTHOR("Daniel Mack <[email protected]>");
MODULE_DESCRIPTION("Asahi Kasei AK4104 ALSA SoC driver");
MODULE_LICENSE("GPL");