/*
 * MFD driver for twl4030 codec submodule
 *
 * Author:      Peter Ujfalusi <peter.ujfalusi@nokia.com>
 *
 * Copyright:   (C) 2009 Nokia Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/platform_device.h>
#include <linux/i2c/twl.h>
#include <linux/mfd/core.h>
#include <linux/mfd/twl4030-codec.h>

#define TWL4030_CODEC_CELLS     2

static struct platform_device *twl4030_codec_dev;

struct twl4030_codec_resource {
        int request_count;
        u8 reg;
        u8 mask;
};

struct twl4030_codec {
        unsigned int audio_mclk;
        struct mutex mutex;
        struct twl4030_codec_resource resource[TWL4030_CODEC_RES_MAX];
        struct mfd_cell cells[TWL4030_CODEC_CELLS];
};

/*
 * Modify the resource, the function returns the content of the register
 * after the modification.
 */
static int twl4030_codec_set_resource(enum twl4030_codec_res id, int enable)
{
        struct twl4030_codec *codec = platform_get_drvdata(twl4030_codec_dev);
        u8 val;

        twl_i2c_read_u8(TWL4030_MODULE_AUDIO_VOICE, &val,
                        codec->resource[id].reg);

        if (enable)
                val |= codec->resource[id].mask;
        else
                val &= ~codec->resource[id].mask;

        twl_i2c_write_u8(TWL4030_MODULE_AUDIO_VOICE,
                                        val, codec->resource[id].reg);

        return val;
}

static inline int twl4030_codec_get_resource(enum twl4030_codec_res id)
{
        struct twl4030_codec *codec = platform_get_drvdata(twl4030_codec_dev);
        u8 val;

        twl_i2c_read_u8(TWL4030_MODULE_AUDIO_VOICE, &val,
                        codec->resource[id].reg);

        return val;
}

/*
 * Enable the resource.
 * The function returns with error or the content of the register
 */
int twl4030_codec_enable_resource(enum twl4030_codec_res id)
{
        struct twl4030_codec *codec = platform_get_drvdata(twl4030_codec_dev);
        int val;

        if (id >= TWL4030_CODEC_RES_MAX) {
                dev_err(&twl4030_codec_dev->dev,
                                "Invalid resource ID (%u)\n", id);
                return -EINVAL;
        }

        mutex_lock(&codec->mutex);
        if (!codec->resource[id].request_count)
                /* Resource was disabled, enable it */
                val = twl4030_codec_set_resource(id, 1);
        else
                val = twl4030_codec_get_resource(id);

        codec->resource[id].request_count++;
        mutex_unlock(&codec->mutex);

        return val;
}
EXPORT_SYMBOL_GPL(twl4030_codec_enable_resource);

/*
 * Disable the resource.
 * The function returns with error or the content of the register
 */
int twl4030_codec_disable_resource(unsigned id)
{
        struct twl4030_codec *codec = platform_get_drvdata(twl4030_codec_dev);
        int val;

        if (id >= TWL4030_CODEC_RES_MAX) {
                dev_err(&twl4030_codec_dev->dev,
                                "Invalid resource ID (%u)\n", id);
                return -EINVAL;
        }

        mutex_lock(&codec->mutex);
        if (!codec->resource[id].request_count) {
                dev_err(&twl4030_codec_dev->dev,
                        "Resource has been disabled already (%u)\n", id);
                mutex_unlock(&codec->mutex);
                return -EPERM;
        }
        codec->resource[id].request_count--;

        if (!codec->resource[id].request_count)
                /* Resource can be disabled now */
                val = twl4030_codec_set_resource(id, 0);
        else
                val = twl4030_codec_get_resource(id);

        mutex_unlock(&codec->mutex);

        return val;
}
EXPORT_SYMBOL_GPL(twl4030_codec_disable_resource);

unsigned int twl4030_codec_get_mclk(void)
{
        struct twl4030_codec *codec = platform_get_drvdata(twl4030_codec_dev);

        return codec->audio_mclk;
}
EXPORT_SYMBOL_GPL(twl4030_codec_get_mclk);

static int __devinit twl4030_codec_probe(struct platform_device *pdev)
{
        struct twl4030_codec *codec;
        struct twl4030_codec_data *pdata = pdev->dev.platform_data;
        struct mfd_cell *cell = NULL;
        int ret, childs = 0;
        u8 val;

        if (!pdata) {
                dev_err(&pdev->dev, "Platform data is missing\n");
                return -EINVAL;
        }

        /* Configure APLL_INFREQ and disable APLL if enabled */
        val = 0;
        switch (pdata->audio_mclk) {
        case 19200000:
                val |= TWL4030_APLL_INFREQ_19200KHZ;
                break;
        case 26000000:
                val |= TWL4030_APLL_INFREQ_26000KHZ;
                break;
        case 38400000:
                val |= TWL4030_APLL_INFREQ_38400KHZ;
                break;
        default:
                dev_err(&pdev->dev, "Invalid audio_mclk\n");
                return -EINVAL;
        }
        twl_i2c_write_u8(TWL4030_MODULE_AUDIO_VOICE,
                                        val, TWL4030_REG_APLL_CTL);

        codec = kzalloc(sizeof(struct twl4030_codec), GFP_KERNEL);
        if (!codec)
                return -ENOMEM;

        platform_set_drvdata(pdev, codec);

        twl4030_codec_dev = pdev;
        mutex_init(&codec->mutex);
        codec->audio_mclk = pdata->audio_mclk;

        /* Codec power */
        codec->resource[TWL4030_CODEC_RES_POWER].reg = TWL4030_REG_CODEC_MODE;
        codec->resource[TWL4030_CODEC_RES_POWER].mask = TWL4030_CODECPDZ;

        /* PLL */
        codec->resource[TWL4030_CODEC_RES_APLL].reg = TWL4030_REG_APLL_CTL;
        codec->resource[TWL4030_CODEC_RES_APLL].mask = TWL4030_APLL_EN;

        if (pdata->audio) {
                cell = &codec->cells[childs];
                cell->name = "twl4030-codec";
                cell->mfd_data = pdata->audio;
                childs++;
        }
        if (pdata->vibra) {
                cell = &codec->cells[childs];
                cell->name = "twl4030-vibra";
                cell->mfd_data = pdata->vibra;
                childs++;
        }

        if (childs)
                ret = mfd_add_devices(&pdev->dev, pdev->id, codec->cells,
                                      childs, NULL, 0);
        else {
                dev_err(&pdev->dev, "No platform data found for childs\n");
                ret = -ENODEV;
        }

        if (!ret)
                return 0;

        platform_set_drvdata(pdev, NULL);
        kfree(codec);
        twl4030_codec_dev = NULL;
        return ret;
}

static int __devexit twl4030_codec_remove(struct platform_device *pdev)
{
        struct twl4030_codec *codec = platform_get_drvdata(pdev);

        mfd_remove_devices(&pdev->dev);
        platform_set_drvdata(pdev, NULL);
        kfree(codec);
        twl4030_codec_dev = NULL;

        return 0;
}

MODULE_ALIAS("platform:twl4030-audio");

static struct platform_driver twl4030_codec_driver = {
        .probe          = twl4030_codec_probe,
        .remove         = __devexit_p(twl4030_codec_remove),
        .driver         = {
                .owner  = THIS_MODULE,
                .name   = "twl4030-audio",
        },
};

static int __devinit twl4030_codec_init(void)
{
        return platform_driver_register(&twl4030_codec_driver);
}
module_init(twl4030_codec_init);

static void __devexit twl4030_codec_exit(void)
{
        platform_driver_unregister(&twl4030_codec_driver);
}
module_exit(twl4030_codec_exit);

MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@nokia.com>");
MODULE_LICENSE("GPL");