/*
 * Apple Onboard Audio driver for tas codec
 *
 * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
 *
 * GPL v2, can be found in COPYING.
 *
 * Open questions:
 *  - How to distinguish between 3004 and versions?
 *
 * FIXMEs:
 *  - This codec driver doesn't honour the 'connected'
 *    property of the aoa_codec struct, hence if
 *    it is used in machines where not everything is
 *    connected it will display wrong mixer elements.
 *  - Driver assumes that the microphone is always
 *    monaureal and connected to the right channel of
 *    the input. This should also be a codec-dependent
 *    flag, maybe the codec should have 3 different
 *    bits for the three different possibilities how
 *    it can be hooked up...
 *    But as long as I don't see any hardware hooked
 *    up that way...
 *  - As Apple notes in their code, the tas3004 seems
 *    to delay the right channel by one sample. You can
 *    see this when for example recording stereo in
 *    audacity, or recording the tas output via cable
 *    on another machine (use a sinus generator or so).
 *    I tried programming the BiQuads but couldn't
 *    make the delay work, maybe someone can read the
 *    datasheet and fix it. The relevant Apple comment
 *    is in AppleTAS3004Audio.cpp lines 1637 ff. Note
 *    that their comment describing how they program
 *    the filters sucks...
 *
 * Other things:
 *  - this should actually register *two* aoa_codec
 *    structs since it has two inputs. Then it must
 *    use the prepare callback to forbid running the
 *    secondary output on a different clock.
 *    Also, whatever bus knows how to do this must
 *    provide two soundbus_dev devices and the fabric
 *    must be able to link them correctly.
 *
 *    I don't even know if Apple ever uses the second
 *    port on the tas3004 though, I don't think their
 *    i2s controllers can even do it. OTOH, they all
 *    derive the clocks from common clocks, so it
 *    might just be possible. The framework allows the
 *    codec to refine the transfer_info items in the
 *    usable callback, so we can simply remove the
 *    rates the second instance is not using when it
 *    actually is in use.
 *    Maybe we'll need to make the sound busses have
 *    a 'clock group id' value so the codec can
 *    determine if the two outputs can be driven at
 *    the same time. But that is likely overkill, up
 *    to the fabric to not link them up incorrectly,
 *    and up to the hardware designer to not wire
 *    them up in some weird unusable way.
 */
#include <stddef.h>
#include <linux/i2c.h>
#include <asm/pmac_low_i2c.h>
#include <asm/prom.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/mutex.h>

MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("tas codec driver for snd-aoa");

#include "tas.h"
#include "tas-gain-table.h"
#include "tas-basstreble.h"
#include "../aoa.h"
#include "../soundbus/soundbus.h"

#define PFX "snd-aoa-codec-tas: "


struct tas {
        struct aoa_codec        codec;
        struct i2c_client       *i2c;
        u32                     mute_l:1, mute_r:1 ,
                                controls_created:1 ,
                                drc_enabled:1,
                                hw_enabled:1;
        u8                      cached_volume_l, cached_volume_r;
        u8                      mixer_l[3], mixer_r[3];
        u8                      bass, treble;
        u8                      acr;
        int                     drc_range;
        /* protects hardware access against concurrency from
         * userspace when hitting controls and during
         * codec init/suspend/resume */
        struct mutex            mtx;
};

static int tas_reset_init(struct tas *tas);

static struct tas *codec_to_tas(struct aoa_codec *codec)
{
        return container_of(codec, struct tas, codec);
}

static inline int tas_write_reg(struct tas *tas, u8 reg, u8 len, u8 *data)
{
        if (len == 1)
                return i2c_smbus_write_byte_data(tas->i2c, reg, *data);
        else
                return i2c_smbus_write_i2c_block_data(tas->i2c, reg, len, data);
}

static void tas3004_set_drc(struct tas *tas)
{
        unsigned char val[6];

        if (tas->drc_enabled)
                val[0] = 0x50; /* 3:1 above threshold */
        else
                val[0] = 0x51; /* disabled */
        val[1] = 0x02; /* 1:1 below threshold */
        if (tas->drc_range > 0xef)
                val[2] = 0xef;
        else if (tas->drc_range < 0)
                val[2] = 0x00;
        else
                val[2] = tas->drc_range;
        val[3] = 0xb0;
        val[4] = 0x60;
        val[5] = 0xa0;

        tas_write_reg(tas, TAS_REG_DRC, 6, val);
}

static void tas_set_treble(struct tas *tas)
{
        u8 tmp;

        tmp = tas3004_treble(tas->treble);
        tas_write_reg(tas, TAS_REG_TREBLE, 1, &tmp);
}

static void tas_set_bass(struct tas *tas)
{
        u8 tmp;

        tmp = tas3004_bass(tas->bass);
        tas_write_reg(tas, TAS_REG_BASS, 1, &tmp);
}

static void tas_set_volume(struct tas *tas)
{
        u8 block[6];
        int tmp;
        u8 left, right;

        left = tas->cached_volume_l;
        right = tas->cached_volume_r;

        if (left > 177) left = 177;
        if (right > 177) right = 177;

        if (tas->mute_l) left = 0;
        if (tas->mute_r) right = 0;

        /* analysing the volume and mixer tables shows
         * that they are similar enough when we shift
         * the mixer table down by 4 bits. The error
         * is miniscule, in just one item the error
         * is 1, at a value of 0x07f17b (mixer table
         * value is 0x07f17a) */
        tmp = tas_gaintable[left];
        block[0] = tmp>>20;
        block[1] = tmp>>12;
        block[2] = tmp>>4;
        tmp = tas_gaintable[right];
        block[3] = tmp>>20;
        block[4] = tmp>>12;
        block[5] = tmp>>4;
        tas_write_reg(tas, TAS_REG_VOL, 6, block);
}

static void tas_set_mixer(struct tas *tas)
{
        u8 block[9];
        int tmp, i;
        u8 val;

        for (i=0;i<3;i++) {
                val = tas->mixer_l[i];
                if (val > 177) val = 177;
                tmp = tas_gaintable[val];
                block[3*i+0] = tmp>>16;
                block[3*i+1] = tmp>>8;
                block[3*i+2] = tmp;
        }
        tas_write_reg(tas, TAS_REG_LMIX, 9, block);

        for (i=0;i<3;i++) {
                val = tas->mixer_r[i];
                if (val > 177) val = 177;
                tmp = tas_gaintable[val];
                block[3*i+0] = tmp>>16;
                block[3*i+1] = tmp>>8;
                block[3*i+2] = tmp;
        }
        tas_write_reg(tas, TAS_REG_RMIX, 9, block);
}

/* alsa stuff */

static int tas_dev_register(struct snd_device *dev)
{
        return 0;
}

static struct snd_device_ops ops = {
        .dev_register = tas_dev_register,
};

static int tas_snd_vol_info(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_info *uinfo)
{
        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
        uinfo->count = 2;
        uinfo->value.integer.min = 0;
        uinfo->value.integer.max = 177;
        return 0;
}

static int tas_snd_vol_get(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        mutex_lock(&tas->mtx);
        ucontrol->value.integer.value[0] = tas->cached_volume_l;
        ucontrol->value.integer.value[1] = tas->cached_volume_r;
        mutex_unlock(&tas->mtx);
        return 0;
}

static int tas_snd_vol_put(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        if (ucontrol->value.integer.value[0] < 0 ||
            ucontrol->value.integer.value[0] > 177)
                return -EINVAL;
        if (ucontrol->value.integer.value[1] < 0 ||
            ucontrol->value.integer.value[1] > 177)
                return -EINVAL;

        mutex_lock(&tas->mtx);
        if (tas->cached_volume_l == ucontrol->value.integer.value[0]
         && tas->cached_volume_r == ucontrol->value.integer.value[1]) {
                mutex_unlock(&tas->mtx);
                return 0;
        }

        tas->cached_volume_l = ucontrol->value.integer.value[0];
        tas->cached_volume_r = ucontrol->value.integer.value[1];
        if (tas->hw_enabled)
                tas_set_volume(tas);
        mutex_unlock(&tas->mtx);
        return 1;
}

static struct snd_kcontrol_new volume_control = {
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
        .name = "Master Playback Volume",
        .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
        .info = tas_snd_vol_info,
        .get = tas_snd_vol_get,
        .put = tas_snd_vol_put,
};

#define tas_snd_mute_info       snd_ctl_boolean_stereo_info

static int tas_snd_mute_get(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        mutex_lock(&tas->mtx);
        ucontrol->value.integer.value[0] = !tas->mute_l;
        ucontrol->value.integer.value[1] = !tas->mute_r;
        mutex_unlock(&tas->mtx);
        return 0;
}

static int tas_snd_mute_put(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        mutex_lock(&tas->mtx);
        if (tas->mute_l == !ucontrol->value.integer.value[0]
         && tas->mute_r == !ucontrol->value.integer.value[1]) {
                mutex_unlock(&tas->mtx);
                return 0;
        }

        tas->mute_l = !ucontrol->value.integer.value[0];
        tas->mute_r = !ucontrol->value.integer.value[1];
        if (tas->hw_enabled)
                tas_set_volume(tas);
        mutex_unlock(&tas->mtx);
        return 1;
}

static struct snd_kcontrol_new mute_control = {
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
        .name = "Master Playback Switch",
        .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
        .info = tas_snd_mute_info,
        .get = tas_snd_mute_get,
        .put = tas_snd_mute_put,
};

static int tas_snd_mixer_info(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_info *uinfo)
{
        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
        uinfo->count = 2;
        uinfo->value.integer.min = 0;
        uinfo->value.integer.max = 177;
        return 0;
}

static int tas_snd_mixer_get(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);
        int idx = kcontrol->private_value;

        mutex_lock(&tas->mtx);
        ucontrol->value.integer.value[0] = tas->mixer_l[idx];
        ucontrol->value.integer.value[1] = tas->mixer_r[idx];
        mutex_unlock(&tas->mtx);

        return 0;
}

static int tas_snd_mixer_put(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);
        int idx = kcontrol->private_value;

        mutex_lock(&tas->mtx);
        if (tas->mixer_l[idx] == ucontrol->value.integer.value[0]
         && tas->mixer_r[idx] == ucontrol->value.integer.value[1]) {
                mutex_unlock(&tas->mtx);
                return 0;
        }

        tas->mixer_l[idx] = ucontrol->value.integer.value[0];
        tas->mixer_r[idx] = ucontrol->value.integer.value[1];

        if (tas->hw_enabled)
                tas_set_mixer(tas);
        mutex_unlock(&tas->mtx);
        return 1;
}

#define MIXER_CONTROL(n,descr,idx)                      \
static struct snd_kcontrol_new n##_control = {          \
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,            \
        .name = descr " Playback Volume",               \
        .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,      \
        .info = tas_snd_mixer_info,                     \
        .get = tas_snd_mixer_get,                       \
        .put = tas_snd_mixer_put,                       \
        .private_value = idx,                           \
}

MIXER_CONTROL(pcm1, "PCM", 0);
MIXER_CONTROL(monitor, "Monitor", 2);

static int tas_snd_drc_range_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 = TAS3004_DRC_MAX;
        return 0;
}

static int tas_snd_drc_range_get(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        mutex_lock(&tas->mtx);
        ucontrol->value.integer.value[0] = tas->drc_range;
        mutex_unlock(&tas->mtx);
        return 0;
}

static int tas_snd_drc_range_put(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        if (ucontrol->value.integer.value[0] < 0 ||
            ucontrol->value.integer.value[0] > TAS3004_DRC_MAX)
                return -EINVAL;

        mutex_lock(&tas->mtx);
        if (tas->drc_range == ucontrol->value.integer.value[0]) {
                mutex_unlock(&tas->mtx);
                return 0;
        }

        tas->drc_range = ucontrol->value.integer.value[0];
        if (tas->hw_enabled)
                tas3004_set_drc(tas);
        mutex_unlock(&tas->mtx);
        return 1;
}

static struct snd_kcontrol_new drc_range_control = {
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
        .name = "DRC Range",
        .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
        .info = tas_snd_drc_range_info,
        .get = tas_snd_drc_range_get,
        .put = tas_snd_drc_range_put,
};

#define tas_snd_drc_switch_info         snd_ctl_boolean_mono_info

static int tas_snd_drc_switch_get(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        mutex_lock(&tas->mtx);
        ucontrol->value.integer.value[0] = tas->drc_enabled;
        mutex_unlock(&tas->mtx);
        return 0;
}

static int tas_snd_drc_switch_put(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        mutex_lock(&tas->mtx);
        if (tas->drc_enabled == ucontrol->value.integer.value[0]) {
                mutex_unlock(&tas->mtx);
                return 0;
        }

        tas->drc_enabled = !!ucontrol->value.integer.value[0];
        if (tas->hw_enabled)
                tas3004_set_drc(tas);
        mutex_unlock(&tas->mtx);
        return 1;
}

static struct snd_kcontrol_new drc_switch_control = {
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
        .name = "DRC Range Switch",
        .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
        .info = tas_snd_drc_switch_info,
        .get = tas_snd_drc_switch_get,
        .put = tas_snd_drc_switch_put,
};

static int tas_snd_capture_source_info(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_info *uinfo)
{
        static char *texts[] = { "Line-In", "Microphone" };

        uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
        uinfo->count = 1;
        uinfo->value.enumerated.items = 2;
        if (uinfo->value.enumerated.item > 1)
                uinfo->value.enumerated.item = 1;
        strcpy(uinfo->value.enumerated.name, texts[uinfo->value.enumerated.item]);
        return 0;
}

static int tas_snd_capture_source_get(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        mutex_lock(&tas->mtx);
        ucontrol->value.enumerated.item[0] = !!(tas->acr & TAS_ACR_INPUT_B);
        mutex_unlock(&tas->mtx);
        return 0;
}

static int tas_snd_capture_source_put(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);
        int oldacr;

        if (ucontrol->value.enumerated.item[0] > 1)
                return -EINVAL;
        mutex_lock(&tas->mtx);
        oldacr = tas->acr;

        /*
         * Despite what the data sheet says in one place, the
         * TAS_ACR_B_MONAUREAL bit forces mono output even when
         * input A (line in) is selected.
         */
        tas->acr &= ~(TAS_ACR_INPUT_B | TAS_ACR_B_MONAUREAL);
        if (ucontrol->value.enumerated.item[0])
                tas->acr |= TAS_ACR_INPUT_B | TAS_ACR_B_MONAUREAL |
                      TAS_ACR_B_MON_SEL_RIGHT;
        if (oldacr == tas->acr) {
                mutex_unlock(&tas->mtx);
                return 0;
        }
        if (tas->hw_enabled)
                tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr);
        mutex_unlock(&tas->mtx);
        return 1;
}

static struct snd_kcontrol_new capture_source_control = {
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
        /* If we name this 'Input Source', it properly shows up in
         * alsamixer as a selection, * but it's shown under the
         * 'Playback' category.
         * If I name it 'Capture Source', it shows up in strange
         * ways (two bools of which one can be selected at a
         * time) but at least it's shown in the 'Capture'
         * category.
         * I was told that this was due to backward compatibility,
         * but I don't understand then why the mangling is *not*
         * done when I name it "Input Source".....
         */
        .name = "Capture Source",
        .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
        .info = tas_snd_capture_source_info,
        .get = tas_snd_capture_source_get,
        .put = tas_snd_capture_source_put,
};

static int tas_snd_treble_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 = TAS3004_TREBLE_MIN;
        uinfo->value.integer.max = TAS3004_TREBLE_MAX;
        return 0;
}

static int tas_snd_treble_get(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        mutex_lock(&tas->mtx);
        ucontrol->value.integer.value[0] = tas->treble;
        mutex_unlock(&tas->mtx);
        return 0;
}

static int tas_snd_treble_put(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        if (ucontrol->value.integer.value[0] < TAS3004_TREBLE_MIN ||
            ucontrol->value.integer.value[0] > TAS3004_TREBLE_MAX)
                return -EINVAL;
        mutex_lock(&tas->mtx);
        if (tas->treble == ucontrol->value.integer.value[0]) {
                mutex_unlock(&tas->mtx);
                return 0;
        }

        tas->treble = ucontrol->value.integer.value[0];
        if (tas->hw_enabled)
                tas_set_treble(tas);
        mutex_unlock(&tas->mtx);
        return 1;
}

static struct snd_kcontrol_new treble_control = {
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
        .name = "Treble",
        .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
        .info = tas_snd_treble_info,
        .get = tas_snd_treble_get,
        .put = tas_snd_treble_put,
};

static int tas_snd_bass_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 = TAS3004_BASS_MIN;
        uinfo->value.integer.max = TAS3004_BASS_MAX;
        return 0;
}

static int tas_snd_bass_get(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        mutex_lock(&tas->mtx);
        ucontrol->value.integer.value[0] = tas->bass;
        mutex_unlock(&tas->mtx);
        return 0;
}

static int tas_snd_bass_put(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct tas *tas = snd_kcontrol_chip(kcontrol);

        if (ucontrol->value.integer.value[0] < TAS3004_BASS_MIN ||
            ucontrol->value.integer.value[0] > TAS3004_BASS_MAX)
                return -EINVAL;
        mutex_lock(&tas->mtx);
        if (tas->bass == ucontrol->value.integer.value[0]) {
                mutex_unlock(&tas->mtx);
                return 0;
        }

        tas->bass = ucontrol->value.integer.value[0];
        if (tas->hw_enabled)
                tas_set_bass(tas);
        mutex_unlock(&tas->mtx);
        return 1;
}

static struct snd_kcontrol_new bass_control = {
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
        .name = "Bass",
        .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
        .info = tas_snd_bass_info,
        .get = tas_snd_bass_get,
        .put = tas_snd_bass_put,
};

static struct transfer_info tas_transfers[] = {
        {
                /* input */
                .formats = SNDRV_PCM_FMTBIT_S16_BE | SNDRV_PCM_FMTBIT_S24_BE,
                .rates = SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
                .transfer_in = 1,
        },
        {
                /* output */
                .formats = SNDRV_PCM_FMTBIT_S16_BE | SNDRV_PCM_FMTBIT_S24_BE,
                .rates = SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
                .transfer_in = 0,
        },
        {}
};

static int tas_usable(struct codec_info_item *cii,
                      struct transfer_info *ti,
                      struct transfer_info *out)
{
        return 1;
}

static int tas_reset_init(struct tas *tas)
{
        u8 tmp;

        tas->codec.gpio->methods->all_amps_off(tas->codec.gpio);
        msleep(5);
        tas->codec.gpio->methods->set_hw_reset(tas->codec.gpio, 0);
        msleep(5);
        tas->codec.gpio->methods->set_hw_reset(tas->codec.gpio, 1);
        msleep(20);
        tas->codec.gpio->methods->set_hw_reset(tas->codec.gpio, 0);
        msleep(10);
        tas->codec.gpio->methods->all_amps_restore(tas->codec.gpio);

        tmp = TAS_MCS_SCLK64 | TAS_MCS_SPORT_MODE_I2S | TAS_MCS_SPORT_WL_24BIT;
        if (tas_write_reg(tas, TAS_REG_MCS, 1, &tmp))
                goto outerr;

        tas->acr |= TAS_ACR_ANALOG_PDOWN;
        if (tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr))
                goto outerr;

        tmp = 0;
        if (tas_write_reg(tas, TAS_REG_MCS2, 1, &tmp))
                goto outerr;

        tas3004_set_drc(tas);

        /* Set treble & bass to 0dB */
        tas->treble = TAS3004_TREBLE_ZERO;
        tas->bass = TAS3004_BASS_ZERO;
        tas_set_treble(tas);
        tas_set_bass(tas);

        tas->acr &= ~TAS_ACR_ANALOG_PDOWN;
        if (tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr))
                goto outerr;

        return 0;
 outerr:
        return -ENODEV;
}

static int tas_switch_clock(struct codec_info_item *cii, enum clock_switch clock)
{
        struct tas *tas = cii->codec_data;

        switch(clock) {
        case CLOCK_SWITCH_PREPARE_SLAVE:
                /* Clocks are going away, mute mute mute */
                tas->codec.gpio->methods->all_amps_off(tas->codec.gpio);
                tas->hw_enabled = 0;
                break;
        case CLOCK_SWITCH_SLAVE:
                /* Clocks are back, re-init the codec */
                mutex_lock(&tas->mtx);
                tas_reset_init(tas);
                tas_set_volume(tas);
                tas_set_mixer(tas);
                tas->hw_enabled = 1;
                tas->codec.gpio->methods->all_amps_restore(tas->codec.gpio);
                mutex_unlock(&tas->mtx);
                break;
        default:
                /* doesn't happen as of now */
                return -EINVAL;
        }
        return 0;
}

#ifdef CONFIG_PM
/* we are controlled via i2c and assume that is always up
 * If that wasn't the case, we'd have to suspend once
 * our i2c device is suspended, and then take note of that! */
static int tas_suspend(struct tas *tas)
{
        mutex_lock(&tas->mtx);
        tas->hw_enabled = 0;
        tas->acr |= TAS_ACR_ANALOG_PDOWN;
        tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr);
        mutex_unlock(&tas->mtx);
        return 0;
}

static int tas_resume(struct tas *tas)
{
        /* reset codec */
        mutex_lock(&tas->mtx);
        tas_reset_init(tas);
        tas_set_volume(tas);
        tas_set_mixer(tas);
        tas->hw_enabled = 1;
        mutex_unlock(&tas->mtx);
        return 0;
}

static int _tas_suspend(struct codec_info_item *cii, pm_message_t state)
{
        return tas_suspend(cii->codec_data);
}

static int _tas_resume(struct codec_info_item *cii)
{
        return tas_resume(cii->codec_data);
}
#else /* CONFIG_PM */
#define _tas_suspend    NULL
#define _tas_resume     NULL
#endif /* CONFIG_PM */

static struct codec_info tas_codec_info = {
        .transfers = tas_transfers,
        /* in theory, we can drive it at 512 too...
         * but so far the framework doesn't allow
         * for that and I don't see much point in it. */
        .sysclock_factor = 256,
        /* same here, could be 32 for just one 16 bit format */
        .bus_factor = 64,
        .owner = THIS_MODULE,
        .usable = tas_usable,
        .switch_clock = tas_switch_clock,
        .suspend = _tas_suspend,
        .resume = _tas_resume,
};

static int tas_init_codec(struct aoa_codec *codec)
{
        struct tas *tas = codec_to_tas(codec);
        int err;

        if (!tas->codec.gpio || !tas->codec.gpio->methods) {
                printk(KERN_ERR PFX "gpios not assigned!!\n");
                return -EINVAL;
        }

        mutex_lock(&tas->mtx);
        if (tas_reset_init(tas)) {
                printk(KERN_ERR PFX "tas failed to initialise\n");
                mutex_unlock(&tas->mtx);
                return -ENXIO;
        }
        tas->hw_enabled = 1;
        mutex_unlock(&tas->mtx);

        if (tas->codec.soundbus_dev->attach_codec(tas->codec.soundbus_dev,
                                                   aoa_get_card(),
                                                   &tas_codec_info, tas)) {
                printk(KERN_ERR PFX "error attaching tas to soundbus\n");
                return -ENODEV;
        }

        if (aoa_snd_device_new(SNDRV_DEV_LOWLEVEL, tas, &ops)) {
                printk(KERN_ERR PFX "failed to create tas snd device!\n");
                return -ENODEV;
        }
        err = aoa_snd_ctl_add(snd_ctl_new1(&volume_control, tas));
        if (err)
                goto error;

        err = aoa_snd_ctl_add(snd_ctl_new1(&mute_control, tas));
        if (err)
                goto error;

        err = aoa_snd_ctl_add(snd_ctl_new1(&pcm1_control, tas));
        if (err)
                goto error;

        err = aoa_snd_ctl_add(snd_ctl_new1(&monitor_control, tas));
        if (err)
                goto error;

        err = aoa_snd_ctl_add(snd_ctl_new1(&capture_source_control, tas));
        if (err)
                goto error;

        err = aoa_snd_ctl_add(snd_ctl_new1(&drc_range_control, tas));
        if (err)
                goto error;

        err = aoa_snd_ctl_add(snd_ctl_new1(&drc_switch_control, tas));
        if (err)
                goto error;

        err = aoa_snd_ctl_add(snd_ctl_new1(&treble_control, tas));
        if (err)
                goto error;

        err = aoa_snd_ctl_add(snd_ctl_new1(&bass_control, tas));
        if (err)
                goto error;

        return 0;
 error:
        tas->codec.soundbus_dev->detach_codec(tas->codec.soundbus_dev, tas);
        snd_device_free(aoa_get_card(), tas);
        return err;
}

static void tas_exit_codec(struct aoa_codec *codec)
{
        struct tas *tas = codec_to_tas(codec);

        if (!tas->codec.soundbus_dev)
                return;
        tas->codec.soundbus_dev->detach_codec(tas->codec.soundbus_dev, tas);
}


static int tas_create(struct i2c_adapter *adapter,
                       struct device_node *node,
                       int addr)
{
        struct i2c_board_info info;
        struct i2c_client *client;

        memset(&info, 0, sizeof(struct i2c_board_info));
        strlcpy(info.type, "aoa_codec_tas", I2C_NAME_SIZE);
        info.addr = addr;
        info.platform_data = node;

        client = i2c_new_device(adapter, &info);
        if (!client)
                return -ENODEV;
        /*
         * We know the driver is already loaded, so the device should be
         * already bound. If not it means binding failed, and then there
         * is no point in keeping the device instantiated.
         */
        if (!client->driver) {
                i2c_unregister_device(client);
                return -ENODEV;
        }

        /*
         * Let i2c-core delete that device on driver removal.
         * This is safe because i2c-core holds the core_lock mutex for us.
         */
        list_add_tail(&client->detected, &client->driver->clients);
        return 0;
}

static int tas_i2c_probe(struct i2c_client *client,
                         const struct i2c_device_id *id)
{
        struct device_node *node = client->dev.platform_data;
        struct tas *tas;

        tas = kzalloc(sizeof(struct tas), GFP_KERNEL);

        if (!tas)
                return -ENOMEM;

        mutex_init(&tas->mtx);
        tas->i2c = client;
        i2c_set_clientdata(client, tas);

        /* seems that half is a saner default */
        tas->drc_range = TAS3004_DRC_MAX / 2;

        strlcpy(tas->codec.name, "tas", MAX_CODEC_NAME_LEN);
        tas->codec.owner = THIS_MODULE;
        tas->codec.init = tas_init_codec;
        tas->codec.exit = tas_exit_codec;
        tas->codec.node = of_node_get(node);

        if (aoa_codec_register(&tas->codec)) {
                goto fail;
        }
        printk(KERN_DEBUG
               "snd-aoa-codec-tas: tas found, addr 0x%02x on %s\n",
               (unsigned int)client->addr, node->full_name);
        return 0;
 fail:
        mutex_destroy(&tas->mtx);
        kfree(tas);
        return -EINVAL;
}

static int tas_i2c_attach(struct i2c_adapter *adapter)
{
        struct device_node *busnode, *dev = NULL;
        struct pmac_i2c_bus *bus;

        bus = pmac_i2c_adapter_to_bus(adapter);
        if (bus == NULL)
                return -ENODEV;
        busnode = pmac_i2c_get_bus_node(bus);

        while ((dev = of_get_next_child(busnode, dev)) != NULL) {
                if (of_device_is_compatible(dev, "tas3004")) {
                        const u32 *addr;
                        printk(KERN_DEBUG PFX "found tas3004\n");
                        addr = of_get_property(dev, "reg", NULL);
                        if (!addr)
                                continue;
                        return tas_create(adapter, dev, ((*addr) >> 1) & 0x7f);
                }
                /* older machines have no 'codec' node with a 'compatible'
                 * property that says 'tas3004', they just have a 'deq'
                 * node without any such property... */
                if (strcmp(dev->name, "deq") == 0) {
                        const u32 *_addr;
                        u32 addr;
                        printk(KERN_DEBUG PFX "found 'deq' node\n");
                        _addr = of_get_property(dev, "i2c-address", NULL);
                        if (!_addr)
                                continue;
                        addr = ((*_addr) >> 1) & 0x7f;
                        /* now, if the address doesn't match any of the two
                         * that a tas3004 can have, we cannot handle this.
                         * I doubt it ever happens but hey. */
                        if (addr != 0x34 && addr != 0x35)
                                continue;
                        return tas_create(adapter, dev, addr);
                }
        }
        return -ENODEV;
}

static int tas_i2c_remove(struct i2c_client *client)
{
        struct tas *tas = i2c_get_clientdata(client);
        u8 tmp = TAS_ACR_ANALOG_PDOWN;

        aoa_codec_unregister(&tas->codec);
        of_node_put(tas->codec.node);

        /* power down codec chip */
        tas_write_reg(tas, TAS_REG_ACR, 1, &tmp);

        mutex_destroy(&tas->mtx);
        kfree(tas);
        return 0;
}

static const struct i2c_device_id tas_i2c_id[] = {
        { "aoa_codec_tas", 0 },
        { }
};

static struct i2c_driver tas_driver = {
        .driver = {
                .name = "aoa_codec_tas",
                .owner = THIS_MODULE,
        },
        .attach_adapter = tas_i2c_attach,
        .probe = tas_i2c_probe,
        .remove = tas_i2c_remove,
        .id_table = tas_i2c_id,
};

static int __init tas_init(void)
{
        return i2c_add_driver(&tas_driver);
}

static void __exit tas_exit(void)
{
        i2c_del_driver(&tas_driver);
}

module_init(tas_init);
module_exit(tas_exit);