/*
 * tlv320aic23b - driver version 0.0.1
 *
 * Copyright (C) 2006 Scott Alfter <salfter@ssai.us>
 *
 * Based on wm8775 driver
 *
 * Copyright (C) 2004 Ulf Eklund <ivtv at eklund.to>
 * Copyright (C) 2005 Hans Verkuil <hverkuil@xs4all.nl>
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/ioctl.h>
#include <asm/uaccess.h>
#include <linux/i2c.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>

MODULE_DESCRIPTION("tlv320aic23b driver");
MODULE_AUTHOR("Scott Alfter, Ulf Eklund, Hans Verkuil");
MODULE_LICENSE("GPL");


/* ----------------------------------------------------------------------- */

struct tlv320aic23b_state {
        struct v4l2_subdev sd;
        u8 muted;
};

static inline struct tlv320aic23b_state *to_state(struct v4l2_subdev *sd)
{
        return container_of(sd, struct tlv320aic23b_state, sd);
}

static int tlv320aic23b_write(struct v4l2_subdev *sd, int reg, u16 val)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int i;

        if ((reg < 0 || reg > 9) && (reg != 15)) {
                v4l2_err(sd, "Invalid register R%d\n", reg);
                return -1;
        }

        for (i = 0; i < 3; i++)
                if (i2c_smbus_write_byte_data(client,
                                (reg << 1) | (val >> 8), val & 0xff) == 0)
                        return 0;
        v4l2_err(sd, "I2C: cannot write %03x to register R%d\n", val, reg);
        return -1;
}

static int tlv320aic23b_s_clock_freq(struct v4l2_subdev *sd, u32 freq)
{
        switch (freq) {
        case 32000: /* set sample rate to 32 kHz */
                tlv320aic23b_write(sd, 8, 0x018);
                break;
        case 44100: /* set sample rate to 44.1 kHz */
                tlv320aic23b_write(sd, 8, 0x022);
                break;
        case 48000: /* set sample rate to 48 kHz */
                tlv320aic23b_write(sd, 8, 0x000);
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static int tlv320aic23b_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
{
        struct tlv320aic23b_state *state = to_state(sd);

        if (ctrl->id != V4L2_CID_AUDIO_MUTE)
                return -EINVAL;
        ctrl->value = state->muted;
        return 0;
}

static int tlv320aic23b_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
{
        struct tlv320aic23b_state *state = to_state(sd);

        if (ctrl->id != V4L2_CID_AUDIO_MUTE)
                return -EINVAL;
        state->muted = ctrl->value;
        tlv320aic23b_write(sd, 0, 0x180); /* mute both channels */
        /* set gain on both channels to +3.0 dB */
        if (!state->muted)
                tlv320aic23b_write(sd, 0, 0x119);
        return 0;
}

static int tlv320aic23b_log_status(struct v4l2_subdev *sd)
{
        struct tlv320aic23b_state *state = to_state(sd);

        v4l2_info(sd, "Input: %s\n", state->muted ? "muted" : "active");
        return 0;
}

/* ----------------------------------------------------------------------- */

static const struct v4l2_subdev_core_ops tlv320aic23b_core_ops = {
        .log_status = tlv320aic23b_log_status,
        .g_ctrl = tlv320aic23b_g_ctrl,
        .s_ctrl = tlv320aic23b_s_ctrl,
};

static const struct v4l2_subdev_audio_ops tlv320aic23b_audio_ops = {
        .s_clock_freq = tlv320aic23b_s_clock_freq,
};

static const struct v4l2_subdev_ops tlv320aic23b_ops = {
        .core = &tlv320aic23b_core_ops,
        .audio = &tlv320aic23b_audio_ops,
};

/* ----------------------------------------------------------------------- */

/* i2c implementation */

/*
 * Generic i2c probe
 * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
 */

static int tlv320aic23b_probe(struct i2c_client *client,
                              const struct i2c_device_id *id)
{
        struct tlv320aic23b_state *state;
        struct v4l2_subdev *sd;

        /* Check if the adapter supports the needed features */
        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -EIO;

        v4l_info(client, "chip found @ 0x%x (%s)\n",
                        client->addr << 1, client->adapter->name);

        state = kzalloc(sizeof(struct tlv320aic23b_state), GFP_KERNEL);
        if (state == NULL)
                return -ENOMEM;
        sd = &state->sd;
        v4l2_i2c_subdev_init(sd, client, &tlv320aic23b_ops);
        state->muted = 0;

        /* Initialize tlv320aic23b */

        /* RESET */
        tlv320aic23b_write(sd, 15, 0x000);
        /* turn off DAC & mic input */
        tlv320aic23b_write(sd, 6, 0x00A);
        /* left-justified, 24-bit, master mode */
        tlv320aic23b_write(sd, 7, 0x049);
        /* set gain on both channels to +3.0 dB */
        tlv320aic23b_write(sd, 0, 0x119);
        /* set sample rate to 48 kHz */
        tlv320aic23b_write(sd, 8, 0x000);
        /* activate digital interface */
        tlv320aic23b_write(sd, 9, 0x001);
        return 0;
}

static int tlv320aic23b_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);

        v4l2_device_unregister_subdev(sd);
        kfree(to_state(sd));
        return 0;
}

/* ----------------------------------------------------------------------- */

static const struct i2c_device_id tlv320aic23b_id[] = {
        { "tlv320aic23b", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, tlv320aic23b_id);

static struct i2c_driver tlv320aic23b_driver = {
        .driver = {
                .owner  = THIS_MODULE,
                .name   = "tlv320aic23b",
        },
        .probe          = tlv320aic23b_probe,
        .remove         = tlv320aic23b_remove,
        .id_table       = tlv320aic23b_id,
};

static __init int init_tlv320aic23b(void)
{
        return i2c_add_driver(&tlv320aic23b_driver);
}

static __exit void exit_tlv320aic23b(void)
{
        i2c_del_driver(&tlv320aic23b_driver);
}

module_init(init_tlv320aic23b);
module_exit(exit_tlv320aic23b);