/*
 *   ALSA Driver for the PT2258 volume controller.
 *
 *      Copyright (c) 2006  Jochen Voss <voss@seehuhn.de>
 *
 *   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 <sound/core.h>
#include <sound/control.h>
#include <sound/tlv.h>
#include <sound/i2c.h>
#include <sound/pt2258.h>
#include <linux/module.h>

MODULE_AUTHOR("Jochen Voss <voss@seehuhn.de>");
MODULE_DESCRIPTION("PT2258 volume controller (Princeton Technology Corp.)");
MODULE_LICENSE("GPL");

#define PT2258_CMD_RESET 0xc0
#define PT2258_CMD_UNMUTE 0xf8
#define PT2258_CMD_MUTE 0xf9

static const unsigned char pt2258_channel_code[12] = {
        0x80, 0x90,             /* channel 1: -10dB, -1dB */
        0x40, 0x50,             /* channel 2: -10dB, -1dB */
        0x00, 0x10,             /* channel 3: -10dB, -1dB */
        0x20, 0x30,             /* channel 4: -10dB, -1dB */
        0x60, 0x70,             /* channel 5: -10dB, -1dB */
        0xa0, 0xb0              /* channel 6: -10dB, -1dB */
};

int snd_pt2258_reset(struct snd_pt2258 *pt)
{
        unsigned char bytes[2];
        int i;

        /* reset chip */
        bytes[0] = PT2258_CMD_RESET;
        snd_i2c_lock(pt->i2c_bus);
        if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 1) != 1)
                goto __error;
        snd_i2c_unlock(pt->i2c_bus);

        /* mute all channels */
        pt->mute = 1;
        bytes[0] = PT2258_CMD_MUTE;
        snd_i2c_lock(pt->i2c_bus);
        if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 1) != 1)
                goto __error;
        snd_i2c_unlock(pt->i2c_bus);

        /* set all channels to 0dB */
        for (i = 0; i < 6; ++i)
                pt->volume[i] = 0;
        bytes[0] = 0xd0;
        bytes[1] = 0xe0;
        snd_i2c_lock(pt->i2c_bus);
        if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 2) != 2)
                goto __error;
        snd_i2c_unlock(pt->i2c_bus);

        return 0;

      __error:
        snd_i2c_unlock(pt->i2c_bus);
        snd_printk(KERN_ERR "PT2258 reset failed\n");
        return -EIO;
}

static int pt2258_stereo_volume_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 = 79;
        return 0;
}

static int pt2258_stereo_volume_get(struct snd_kcontrol *kcontrol,
                                    struct snd_ctl_elem_value *ucontrol)
{
        struct snd_pt2258 *pt = kcontrol->private_data;
        int base = kcontrol->private_value;

        /* chip does not support register reads */
        ucontrol->value.integer.value[0] = 79 - pt->volume[base];
        ucontrol->value.integer.value[1] = 79 - pt->volume[base + 1];
        return 0;
}

static int pt2258_stereo_volume_put(struct snd_kcontrol *kcontrol,
                                    struct snd_ctl_elem_value *ucontrol)
{
        struct snd_pt2258 *pt = kcontrol->private_data;
        int base = kcontrol->private_value;
        unsigned char bytes[2];
        int val0, val1;

        val0 = 79 - ucontrol->value.integer.value[0];
        val1 = 79 - ucontrol->value.integer.value[1];
        if (val0 < 0 || val0 > 79 || val1 < 0 || val1 > 79)
                return -EINVAL;
        if (val0 == pt->volume[base] && val1 == pt->volume[base + 1])
                return 0;

        pt->volume[base] = val0;
        bytes[0] = pt2258_channel_code[2 * base] | (val0 / 10);
        bytes[1] = pt2258_channel_code[2 * base + 1] | (val0 % 10);
        snd_i2c_lock(pt->i2c_bus);
        if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 2) != 2)
                goto __error;
        snd_i2c_unlock(pt->i2c_bus);

        pt->volume[base + 1] = val1;
        bytes[0] = pt2258_channel_code[2 * base + 2] | (val1 / 10);
        bytes[1] = pt2258_channel_code[2 * base + 3] | (val1 % 10);
        snd_i2c_lock(pt->i2c_bus);
        if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 2) != 2)
                goto __error;
        snd_i2c_unlock(pt->i2c_bus);

        return 1;

      __error:
        snd_i2c_unlock(pt->i2c_bus);
        snd_printk(KERN_ERR "PT2258 access failed\n");
        return -EIO;
}

#define pt2258_switch_info      snd_ctl_boolean_mono_info

static int pt2258_switch_get(struct snd_kcontrol *kcontrol,
                             struct snd_ctl_elem_value *ucontrol)
{
        struct snd_pt2258 *pt = kcontrol->private_data;

        ucontrol->value.integer.value[0] = !pt->mute;
        return 0;
}

static int pt2258_switch_put(struct snd_kcontrol *kcontrol,
                             struct snd_ctl_elem_value *ucontrol)
{
        struct snd_pt2258 *pt = kcontrol->private_data;
        unsigned char bytes[2];
        int val;

        val = !ucontrol->value.integer.value[0];
        if (pt->mute == val)
                return 0;

        pt->mute = val;
        bytes[0] = val ? PT2258_CMD_MUTE : PT2258_CMD_UNMUTE;
        snd_i2c_lock(pt->i2c_bus);
        if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 1) != 1)
                goto __error;
        snd_i2c_unlock(pt->i2c_bus);

        return 1;

      __error:
        snd_i2c_unlock(pt->i2c_bus);
        snd_printk(KERN_ERR "PT2258 access failed 2\n");
        return -EIO;
}

static const DECLARE_TLV_DB_SCALE(pt2258_db_scale, -7900, 100, 0);

int snd_pt2258_build_controls(struct snd_pt2258 *pt)
{
        struct snd_kcontrol_new knew;
        char *names[3] = {
                "Mic Loopback Playback Volume",
                "Line Loopback Playback Volume",
                "CD Loopback Playback Volume"
        };
        int i, err;

        for (i = 0; i < 3; ++i) {
                memset(&knew, 0, sizeof(knew));
                knew.name = names[i];
                knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
                knew.count = 1;
                knew.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
                    SNDRV_CTL_ELEM_ACCESS_TLV_READ;
                knew.private_value = 2 * i;
                knew.info = pt2258_stereo_volume_info;
                knew.get = pt2258_stereo_volume_get;
                knew.put = pt2258_stereo_volume_put;
                knew.tlv.p = pt2258_db_scale;

                err = snd_ctl_add(pt->card, snd_ctl_new1(&knew, pt));
                if (err < 0)
                        return err;
        }

        memset(&knew, 0, sizeof(knew));
        knew.name = "Loopback Switch";
        knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
        knew.info = pt2258_switch_info;
        knew.get = pt2258_switch_get;
        knew.put = pt2258_switch_put;
        knew.access = 0;
        err = snd_ctl_add(pt->card, snd_ctl_new1(&knew, pt));
        if (err < 0)
                return err;

        return 0;
}

EXPORT_SYMBOL(snd_pt2258_reset);
EXPORT_SYMBOL(snd_pt2258_build_controls);