ak4114.c

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/*
 *  Routines for control of the AK4114 via I2C and 4-wire serial interface
 *  IEC958 (S/PDIF) receiver by Asahi Kasei
 *  Copyright (c) by Jaroslav Kysela <[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.
 *
 *   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/pcm.h>
#include <sound/ak4114.h>
#include <sound/asoundef.h>
#include <sound/info.h>

MODULE_AUTHOR("Jaroslav Kysela <[email protected]>");
MODULE_DESCRIPTION("AK4114 IEC958 (S/PDIF) receiver by Asahi Kasei");
MODULE_LICENSE("GPL");

#define AK4114_ADDR         0x00 /* fixed address */

static void ak4114_stats(struct work_struct *work);
static void ak4114_init_regs(struct ak4114 *chip);

static void reg_write(struct ak4114 *ak4114, unsigned char reg, unsigned char val)
{
    ak4114->write(ak4114->private_data, reg, val);
    if (reg <= AK4114_REG_INT1_MASK)
        ak4114->regmap[reg] = val;
    else if (reg >= AK4114_REG_TXCSB0 && reg <= AK4114_REG_TXCSB4)
        ak4114->txcsb[reg-AK4114_REG_TXCSB0] = val;
}

static inline unsigned char reg_read(struct ak4114 *ak4114, unsigned char reg)
{
    return ak4114->read(ak4114->private_data, reg);
}

#if 0
static void reg_dump(struct ak4114 *ak4114)
{
    int i;

    printk(KERN_DEBUG "AK4114 REG DUMP:\n");
    for (i = 0; i < 0x20; i++)
        printk(KERN_DEBUG "reg[%02x] = %02x (%02x)\n", i, reg_read(ak4114, i), i < sizeof(ak4114->regmap) ? ak4114->regmap[i] : 0);
}
#endif

static void snd_ak4114_free(struct ak4114 *chip)
{
    chip->init = 1; /* don't schedule new work */
    mb();
    cancel_delayed_work_sync(&chip->work);
    kfree(chip);
}

static int snd_ak4114_dev_free(struct snd_device *device)
{
    struct ak4114 *chip = device->device_data;
    snd_ak4114_free(chip);
    return 0;
}

int snd_ak4114_create(struct snd_card *card,
              ak4114_read_t *read, ak4114_write_t *write,
              const unsigned char pgm[7], const unsigned char txcsb[5],
              void *private_data, struct ak4114 **r_ak4114)
{
    struct ak4114 *chip;
    int err = 0;
    unsigned char reg;
    static struct snd_device_ops ops = {
        .dev_free =     snd_ak4114_dev_free,
    };

    chip = kzalloc(sizeof(*chip), GFP_KERNEL);
    if (chip == NULL)
        return -ENOMEM;
    spin_lock_init(&chip->lock);
    chip->card = card;
    chip->read = read;
    chip->write = write;
    chip->private_data = private_data;
    INIT_DELAYED_WORK(&chip->work, ak4114_stats);

    for (reg = 0; reg < 7; reg++)
        chip->regmap[reg] = pgm[reg];
    for (reg = 0; reg < 5; reg++)
        chip->txcsb[reg] = txcsb[reg];

    ak4114_init_regs(chip);

    chip->rcs0 = reg_read(chip, AK4114_REG_RCS0) & ~(AK4114_QINT | AK4114_CINT);
    chip->rcs1 = reg_read(chip, AK4114_REG_RCS1);

    if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0)
        goto __fail;

    if (r_ak4114)
        *r_ak4114 = chip;
    return 0;

      __fail:
    snd_ak4114_free(chip);
    return err < 0 ? err : -EIO;
}

void snd_ak4114_reg_write(struct ak4114 *chip, unsigned char reg, unsigned char mask, unsigned char val)
{
    if (reg <= AK4114_REG_INT1_MASK)
        reg_write(chip, reg, (chip->regmap[reg] & ~mask) | val);
    else if (reg >= AK4114_REG_TXCSB0 && reg <= AK4114_REG_TXCSB4)
        reg_write(chip, reg,
              (chip->txcsb[reg-AK4114_REG_TXCSB0] & ~mask) | val);
}

static void ak4114_init_regs(struct ak4114 *chip)
{
    unsigned char old = chip->regmap[AK4114_REG_PWRDN], reg;

    /* bring the chip to reset state and powerdown state */
    reg_write(chip, AK4114_REG_PWRDN, old & ~(AK4114_RST|AK4114_PWN));
    udelay(200);
    /* release reset, but leave powerdown */
    reg_write(chip, AK4114_REG_PWRDN, (old | AK4114_RST) & ~AK4114_PWN);
    udelay(200);
    for (reg = 1; reg < 7; reg++)
        reg_write(chip, reg, chip->regmap[reg]);
    for (reg = 0; reg < 5; reg++)
        reg_write(chip, reg + AK4114_REG_TXCSB0, chip->txcsb[reg]);
    /* release powerdown, everything is initialized now */
    reg_write(chip, AK4114_REG_PWRDN, old | AK4114_RST | AK4114_PWN);
}

void snd_ak4114_reinit(struct ak4114 *chip)
{
    chip->init = 1;
    mb();
    flush_delayed_work(&chip->work);
    ak4114_init_regs(chip);
    /* bring up statistics / event queing */
    chip->init = 0;
    if (chip->kctls[0])
        schedule_delayed_work(&chip->work, HZ / 10);
}

static unsigned int external_rate(unsigned char rcs1)
{
    switch (rcs1 & (AK4114_FS0|AK4114_FS1|AK4114_FS2|AK4114_FS3)) {
    case AK4114_FS_32000HZ: return 32000;
    case AK4114_FS_44100HZ: return 44100;
    case AK4114_FS_48000HZ: return 48000;
    case AK4114_FS_88200HZ: return 88200;
    case AK4114_FS_96000HZ: return 96000;
    case AK4114_FS_176400HZ: return 176400;
    case AK4114_FS_192000HZ: return 192000;
    default:        return 0;
    }
}

static int snd_ak4114_in_error_info(struct snd_kcontrol *kcontrol,
                    struct snd_ctl_elem_info *uinfo)
{
    uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
    uinfo->count = 1;
    uinfo->value.integer.min = 0;
    uinfo->value.integer.max = LONG_MAX;
    return 0;
}

static int snd_ak4114_in_error_get(struct snd_kcontrol *kcontrol,
                   struct snd_ctl_elem_value *ucontrol)
{
    struct ak4114 *chip = snd_kcontrol_chip(kcontrol);
    long *ptr;

    spin_lock_irq(&chip->lock);
    ptr = (long *)(((char *)chip) + kcontrol->private_value);
    ucontrol->value.integer.value[0] = *ptr;
    *ptr = 0;
    spin_unlock_irq(&chip->lock);
    return 0;
}

#define snd_ak4114_in_bit_info      snd_ctl_boolean_mono_info

static int snd_ak4114_in_bit_get(struct snd_kcontrol *kcontrol,
                 struct snd_ctl_elem_value *ucontrol)
{
    struct ak4114 *chip = snd_kcontrol_chip(kcontrol);
    unsigned char reg = kcontrol->private_value & 0xff;
    unsigned char bit = (kcontrol->private_value >> 8) & 0xff;
    unsigned char inv = (kcontrol->private_value >> 31) & 1;

    ucontrol->value.integer.value[0] = ((reg_read(chip, reg) & (1 << bit)) ? 1 : 0) ^ inv;
    return 0;
}

static int snd_ak4114_rate_info(struct snd_kcontrol *kcontrol,
                struct snd_ctl_elem_info *uinfo)
{
    uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
    uinfo->count = 1;
    uinfo->value.integer.min = 0;
    uinfo->value.integer.max = 192000;
    return 0;
}

static int snd_ak4114_rate_get(struct snd_kcontrol *kcontrol,
                   struct snd_ctl_elem_value *ucontrol)
{
    struct ak4114 *chip = snd_kcontrol_chip(kcontrol);

    ucontrol->value.integer.value[0] = external_rate(reg_read(chip, AK4114_REG_RCS1));
    return 0;
}

static int snd_ak4114_spdif_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
{
    uinfo->type = SNDRV_CTL_ELEM_TYPE_IEC958;
    uinfo->count = 1;
    return 0;
}

static int snd_ak4114_spdif_get(struct snd_kcontrol *kcontrol,
                struct snd_ctl_elem_value *ucontrol)
{
    struct ak4114 *chip = snd_kcontrol_chip(kcontrol);
    unsigned i;

    for (i = 0; i < AK4114_REG_RXCSB_SIZE; i++)
        ucontrol->value.iec958.status[i] = reg_read(chip, AK4114_REG_RXCSB0 + i);
    return 0;
}

static int snd_ak4114_spdif_playback_get(struct snd_kcontrol *kcontrol,
                     struct snd_ctl_elem_value *ucontrol)
{
    struct ak4114 *chip = snd_kcontrol_chip(kcontrol);
    unsigned i;

    for (i = 0; i < AK4114_REG_TXCSB_SIZE; i++)
        ucontrol->value.iec958.status[i] = chip->txcsb[i];
    return 0;
}

static int snd_ak4114_spdif_playback_put(struct snd_kcontrol *kcontrol,
                     struct snd_ctl_elem_value *ucontrol)
{
    struct ak4114 *chip = snd_kcontrol_chip(kcontrol);
    unsigned i;

    for (i = 0; i < AK4114_REG_TXCSB_SIZE; i++)
        reg_write(chip, AK4114_REG_TXCSB0 + i, ucontrol->value.iec958.status[i]);
    return 0;
}

static int snd_ak4114_spdif_mask_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
{
    uinfo->type = SNDRV_CTL_ELEM_TYPE_IEC958;
    uinfo->count = 1;
    return 0;
}

static int snd_ak4114_spdif_mask_get(struct snd_kcontrol *kcontrol,
                      struct snd_ctl_elem_value *ucontrol)
{
    memset(ucontrol->value.iec958.status, 0xff, AK4114_REG_RXCSB_SIZE);
    return 0;
}

static int snd_ak4114_spdif_pinfo(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
{
    uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
    uinfo->value.integer.min = 0;
    uinfo->value.integer.max = 0xffff;
    uinfo->count = 4;
    return 0;
}

static int snd_ak4114_spdif_pget(struct snd_kcontrol *kcontrol,
                 struct snd_ctl_elem_value *ucontrol)
{
    struct ak4114 *chip = snd_kcontrol_chip(kcontrol);
    unsigned short tmp;

    ucontrol->value.integer.value[0] = 0xf8f2;
    ucontrol->value.integer.value[1] = 0x4e1f;
    tmp = reg_read(chip, AK4114_REG_Pc0) | (reg_read(chip, AK4114_REG_Pc1) << 8);
    ucontrol->value.integer.value[2] = tmp;
    tmp = reg_read(chip, AK4114_REG_Pd0) | (reg_read(chip, AK4114_REG_Pd1) << 8);
    ucontrol->value.integer.value[3] = tmp;
    return 0;
}

static int snd_ak4114_spdif_qinfo(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
{
    uinfo->type = SNDRV_CTL_ELEM_TYPE_BYTES;
    uinfo->count = AK4114_REG_QSUB_SIZE;
    return 0;
}

static int snd_ak4114_spdif_qget(struct snd_kcontrol *kcontrol,
                 struct snd_ctl_elem_value *ucontrol)
{
    struct ak4114 *chip = snd_kcontrol_chip(kcontrol);
    unsigned i;

    for (i = 0; i < AK4114_REG_QSUB_SIZE; i++)
        ucontrol->value.bytes.data[i] = reg_read(chip, AK4114_REG_QSUB_ADDR + i);
    return 0;
}

/* Don't forget to change AK4114_CONTROLS define!!! */
static struct snd_kcontrol_new snd_ak4114_iec958_controls[] = {
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 Parity Errors",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_in_error_info,
    .get =      snd_ak4114_in_error_get,
    .private_value = offsetof(struct ak4114, parity_errors),
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 V-Bit Errors",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_in_error_info,
    .get =      snd_ak4114_in_error_get,
    .private_value = offsetof(struct ak4114, v_bit_errors),
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 C-CRC Errors",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_in_error_info,
    .get =      snd_ak4114_in_error_get,
    .private_value = offsetof(struct ak4114, ccrc_errors),
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 Q-CRC Errors",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_in_error_info,
    .get =      snd_ak4114_in_error_get,
    .private_value = offsetof(struct ak4114, qcrc_errors),
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 External Rate",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_rate_info,
    .get =      snd_ak4114_rate_get,
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     SNDRV_CTL_NAME_IEC958("",PLAYBACK,MASK),
    .access =   SNDRV_CTL_ELEM_ACCESS_READ,
    .info =     snd_ak4114_spdif_mask_info,
    .get =      snd_ak4114_spdif_mask_get,
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     SNDRV_CTL_NAME_IEC958("",PLAYBACK,DEFAULT),
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_spdif_info,
    .get =      snd_ak4114_spdif_playback_get,
    .put =      snd_ak4114_spdif_playback_put,
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     SNDRV_CTL_NAME_IEC958("",CAPTURE,MASK),
    .access =   SNDRV_CTL_ELEM_ACCESS_READ,
    .info =     snd_ak4114_spdif_mask_info,
    .get =      snd_ak4114_spdif_mask_get,
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     SNDRV_CTL_NAME_IEC958("",CAPTURE,DEFAULT),
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_spdif_info,
    .get =      snd_ak4114_spdif_get,
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 Preamble Capture Default",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_spdif_pinfo,
    .get =      snd_ak4114_spdif_pget,
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 Q-subcode Capture Default",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_spdif_qinfo,
    .get =      snd_ak4114_spdif_qget,
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 Audio",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_in_bit_info,
    .get =      snd_ak4114_in_bit_get,
    .private_value = (1<<31) | (1<<8) | AK4114_REG_RCS0,
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 Non-PCM Bitstream",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_in_bit_info,
    .get =      snd_ak4114_in_bit_get,
    .private_value = (6<<8) | AK4114_REG_RCS0,
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 DTS Bitstream",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_in_bit_info,
    .get =      snd_ak4114_in_bit_get,
    .private_value = (3<<8) | AK4114_REG_RCS0,
},
{
    .iface =    SNDRV_CTL_ELEM_IFACE_PCM,
    .name =     "IEC958 PPL Lock Status",
    .access =   SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
    .info =     snd_ak4114_in_bit_info,
    .get =      snd_ak4114_in_bit_get,
    .private_value = (1<<31) | (4<<8) | AK4114_REG_RCS0,
}
};


static void snd_ak4114_proc_regs_read(struct snd_info_entry *entry,
        struct snd_info_buffer *buffer)
{
    struct ak4114 *ak4114 = entry->private_data;
    int reg, val;
    /* all ak4114 registers 0x00 - 0x1f */
    for (reg = 0; reg < 0x20; reg++) {
        val = reg_read(ak4114, reg);
        snd_iprintf(buffer, "0x%02x = 0x%02x\n", reg, val);
    }
}

static void snd_ak4114_proc_init(struct ak4114 *ak4114)
{
    struct snd_info_entry *entry;
    if (!snd_card_proc_new(ak4114->card, "ak4114", &entry))
        snd_info_set_text_ops(entry, ak4114, snd_ak4114_proc_regs_read);
}

int snd_ak4114_build(struct ak4114 *ak4114,
             struct snd_pcm_substream *ply_substream,
             struct snd_pcm_substream *cap_substream)
{
    struct snd_kcontrol *kctl;
    unsigned int idx;
    int err;

    if (snd_BUG_ON(!cap_substream))
        return -EINVAL;
    ak4114->playback_substream = ply_substream;
    ak4114->capture_substream = cap_substream;
    for (idx = 0; idx < AK4114_CONTROLS; idx++) {
        kctl = snd_ctl_new1(&snd_ak4114_iec958_controls[idx], ak4114);
        if (kctl == NULL)
            return -ENOMEM;
        if (strstr(kctl->id.name, "Playback")) {
            if (ply_substream == NULL) {
                snd_ctl_free_one(kctl);
                ak4114->kctls[idx] = NULL;
                continue;
            }
            kctl->id.device = ply_substream->pcm->device;
            kctl->id.subdevice = ply_substream->number;
        } else {
            kctl->id.device = cap_substream->pcm->device;
            kctl->id.subdevice = cap_substream->number;
        }
        err = snd_ctl_add(ak4114->card, kctl);
        if (err < 0)
            return err;
        ak4114->kctls[idx] = kctl;
    }
    snd_ak4114_proc_init(ak4114);
    /* trigger workq */
    schedule_delayed_work(&ak4114->work, HZ / 10);
    return 0;
}

/* notify kcontrols if any parameters are changed */
static void ak4114_notify(struct ak4114 *ak4114,
              unsigned char rcs0, unsigned char rcs1,
              unsigned char c0, unsigned char c1)
{
    if (!ak4114->kctls[0])
        return;

    if (rcs0 & AK4114_PAR)
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[0]->id);
    if (rcs0 & AK4114_V)
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[1]->id);
    if (rcs1 & AK4114_CCRC)
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[2]->id);
    if (rcs1 & AK4114_QCRC)
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[3]->id);

    /* rate change */
    if (c1 & 0xf0)
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[4]->id);

    if ((c0 & AK4114_PEM) | (c0 & AK4114_CINT))
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[9]->id);
    if (c0 & AK4114_QINT)
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[10]->id);

    if (c0 & AK4114_AUDION)
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[11]->id);
    if (c0 & AK4114_AUTO)
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[12]->id);
    if (c0 & AK4114_DTSCD)
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[13]->id);
    if (c0 & AK4114_UNLCK)
        snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
                   &ak4114->kctls[14]->id);
}

int snd_ak4114_external_rate(struct ak4114 *ak4114)
{
    unsigned char rcs1;

    rcs1 = reg_read(ak4114, AK4114_REG_RCS1);
    return external_rate(rcs1);
}

int snd_ak4114_check_rate_and_errors(struct ak4114 *ak4114, unsigned int flags)
{
    struct snd_pcm_runtime *runtime = ak4114->capture_substream ? ak4114->capture_substream->runtime : NULL;
    unsigned long _flags;
    int res = 0;
    unsigned char rcs0, rcs1;
    unsigned char c0, c1;

    rcs1 = reg_read(ak4114, AK4114_REG_RCS1);
    if (flags & AK4114_CHECK_NO_STAT)
        goto __rate;
    rcs0 = reg_read(ak4114, AK4114_REG_RCS0);
    spin_lock_irqsave(&ak4114->lock, _flags);
    if (rcs0 & AK4114_PAR)
        ak4114->parity_errors++;
    if (rcs1 & AK4114_V)
        ak4114->v_bit_errors++;
    if (rcs1 & AK4114_CCRC)
        ak4114->ccrc_errors++;
    if (rcs1 & AK4114_QCRC)
        ak4114->qcrc_errors++;
    c0 = (ak4114->rcs0 & (AK4114_QINT | AK4114_CINT | AK4114_PEM | AK4114_AUDION | AK4114_AUTO | AK4114_UNLCK)) ^
                     (rcs0 & (AK4114_QINT | AK4114_CINT | AK4114_PEM | AK4114_AUDION | AK4114_AUTO | AK4114_UNLCK));
    c1 = (ak4114->rcs1 & 0xf0) ^ (rcs1 & 0xf0);
    ak4114->rcs0 = rcs0 & ~(AK4114_QINT | AK4114_CINT);
    ak4114->rcs1 = rcs1;
    spin_unlock_irqrestore(&ak4114->lock, _flags);

    ak4114_notify(ak4114, rcs0, rcs1, c0, c1);
    if (ak4114->change_callback && (c0 | c1) != 0)
        ak4114->change_callback(ak4114, c0, c1);

      __rate:
    /* compare rate */
    res = external_rate(rcs1);
    if (!(flags & AK4114_CHECK_NO_RATE) && runtime && runtime->rate != res) {
        snd_pcm_stream_lock_irqsave(ak4114->capture_substream, _flags);
        if (snd_pcm_running(ak4114->capture_substream)) {
            // printk(KERN_DEBUG "rate changed (%i <- %i)\n", runtime->rate, res);
            snd_pcm_stop(ak4114->capture_substream, SNDRV_PCM_STATE_DRAINING);
            res = 1;
        }
        snd_pcm_stream_unlock_irqrestore(ak4114->capture_substream, _flags);
    }
    return res;
}

static void ak4114_stats(struct work_struct *work)
{
    struct ak4114 *chip = container_of(work, struct ak4114, work.work);

    if (!chip->init)
        snd_ak4114_check_rate_and_errors(chip, chip->check_flags);

    schedule_delayed_work(&chip->work, HZ / 10);
}

EXPORT_SYMBOL(snd_ak4114_create);
EXPORT_SYMBOL(snd_ak4114_reg_write);
EXPORT_SYMBOL(snd_ak4114_reinit);
EXPORT_SYMBOL(snd_ak4114_build);
EXPORT_SYMBOL(snd_ak4114_external_rate);
EXPORT_SYMBOL(snd_ak4114_check_rate_and_errors);