/*
 * Core driver for TPS61050/61052 boost converters, used for while LED
 * driving, audio power amplification, white LED flash, and generic
 * boost conversion. Additionally it provides a 1-bit GPIO pin (out or in)
 * and a flash synchronization pin to synchronize flash events when used as
 * flashgun.
 *
 * Copyright (C) 2011 ST-Ericsson SA
 * Written on behalf of Linaro for ST-Ericsson
 *
 * Author: Linus Walleij <linus.walleij@linaro.org>
 *
 * License terms: GNU General Public License (GPL) version 2
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/gpio.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/regulator/driver.h>
#include <linux/mfd/core.h>
#include <linux/mfd/tps6105x.h>

int tps6105x_set(struct tps6105x *tps6105x, u8 reg, u8 value)
{
        int ret;

        ret = mutex_lock_interruptible(&tps6105x->lock);
        if (ret)
                return ret;
        ret = i2c_smbus_write_byte_data(tps6105x->client, reg, value);
        mutex_unlock(&tps6105x->lock);
        if (ret < 0)
                return ret;

        return 0;
}
EXPORT_SYMBOL(tps6105x_set);

int tps6105x_get(struct tps6105x *tps6105x, u8 reg, u8 *buf)
{
        int ret;

        ret = mutex_lock_interruptible(&tps6105x->lock);
        if (ret)
                return ret;
        ret = i2c_smbus_read_byte_data(tps6105x->client, reg);
        mutex_unlock(&tps6105x->lock);
        if (ret < 0)
                return ret;

        *buf = ret;
        return 0;
}
EXPORT_SYMBOL(tps6105x_get);

/*
 * Masks off the bits in the mask and sets the bits in the bitvalues
 * parameter in one atomic operation
 */
int tps6105x_mask_and_set(struct tps6105x *tps6105x, u8 reg,
                          u8 bitmask, u8 bitvalues)
{
        int ret;
        u8 regval;

        ret = mutex_lock_interruptible(&tps6105x->lock);
        if (ret)
                return ret;
        ret = i2c_smbus_read_byte_data(tps6105x->client, reg);
        if (ret < 0)
                goto fail;
        regval = ret;
        regval = (~bitmask & regval) | (bitmask & bitvalues);
        ret = i2c_smbus_write_byte_data(tps6105x->client, reg, regval);
fail:
        mutex_unlock(&tps6105x->lock);
        if (ret < 0)
                return ret;

        return 0;
}
EXPORT_SYMBOL(tps6105x_mask_and_set);

static int __devinit tps6105x_startup(struct tps6105x *tps6105x)
{
        int ret;
        u8 regval;

        ret = tps6105x_get(tps6105x, TPS6105X_REG_0, &regval);
        if (ret)
                return ret;
        switch (regval >> TPS6105X_REG0_MODE_SHIFT) {
        case TPS6105X_REG0_MODE_SHUTDOWN:
                dev_info(&tps6105x->client->dev,
                         "TPS6105x found in SHUTDOWN mode\n");
                break;
        case TPS6105X_REG0_MODE_TORCH:
                dev_info(&tps6105x->client->dev,
                         "TPS6105x found in TORCH mode\n");
                break;
        case TPS6105X_REG0_MODE_TORCH_FLASH:
                dev_info(&tps6105x->client->dev,
                         "TPS6105x found in FLASH mode\n");
                break;
        case TPS6105X_REG0_MODE_VOLTAGE:
                dev_info(&tps6105x->client->dev,
                         "TPS6105x found in VOLTAGE mode\n");
                break;
        default:
                break;
        }

        return ret;
}

/*
 * MFD cells - we have one cell which is selected operation
 * mode, and we always have a GPIO cell.
 */
static struct mfd_cell tps6105x_cells[] = {
        {
                /* name will be runtime assigned */
                .id = -1,
        },
        {
                .name = "tps6105x-gpio",
                .id = -1,
        },
};

static int __devinit tps6105x_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
{
        struct tps6105x                 *tps6105x;
        struct tps6105x_platform_data   *pdata;
        int ret;
        int i;

        tps6105x = kmalloc(sizeof(*tps6105x), GFP_KERNEL);
        if (!tps6105x)
                return -ENOMEM;

        i2c_set_clientdata(client, tps6105x);
        tps6105x->client = client;
        pdata = client->dev.platform_data;
        tps6105x->pdata = pdata;
        mutex_init(&tps6105x->lock);

        ret = tps6105x_startup(tps6105x);
        if (ret) {
                dev_err(&client->dev, "chip initialization failed\n");
                goto fail;
        }

        /* Remove warning texts when you implement new cell drivers */
        switch (pdata->mode) {
        case TPS6105X_MODE_SHUTDOWN:
                dev_info(&client->dev,
                         "present, not used for anything, only GPIO\n");
                break;
        case TPS6105X_MODE_TORCH:
                tps6105x_cells[0].name = "tps6105x-leds";
                dev_warn(&client->dev,
                         "torch mode is unsupported\n");
                break;
        case TPS6105X_MODE_TORCH_FLASH:
                tps6105x_cells[0].name = "tps6105x-flash";
                dev_warn(&client->dev,
                         "flash mode is unsupported\n");
                break;
        case TPS6105X_MODE_VOLTAGE:
                tps6105x_cells[0].name ="tps6105x-regulator";
                break;
        default:
                break;
        }

        /* Set up and register the platform devices. */
        for (i = 0; i < ARRAY_SIZE(tps6105x_cells); i++) {
                /* One state holder for all drivers, this is simple */
                tps6105x_cells[i].platform_data = tps6105x;
                tps6105x_cells[i].pdata_size = sizeof(*tps6105x);
        }

        ret = mfd_add_devices(&client->dev, 0, tps6105x_cells,
                              ARRAY_SIZE(tps6105x_cells), NULL, 0, NULL);
        if (ret)
                goto fail;

        return 0;

fail:
        kfree(tps6105x);
        return ret;
}

static int __devexit tps6105x_remove(struct i2c_client *client)
{
        struct tps6105x *tps6105x = i2c_get_clientdata(client);

        mfd_remove_devices(&client->dev);

        /* Put chip in shutdown mode */
        tps6105x_mask_and_set(tps6105x, TPS6105X_REG_0,
                TPS6105X_REG0_MODE_MASK,
                TPS6105X_MODE_SHUTDOWN << TPS6105X_REG0_MODE_SHIFT);

        kfree(tps6105x);
        return 0;
}

static const struct i2c_device_id tps6105x_id[] = {
        { "tps61050", 0 },
        { "tps61052", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, tps6105x_id);

static struct i2c_driver tps6105x_driver = {
        .driver = {
                .name   = "tps6105x",
        },
        .probe          = tps6105x_probe,
        .remove         = __devexit_p(tps6105x_remove),
        .id_table       = tps6105x_id,
};

static int __init tps6105x_init(void)
{
        return i2c_add_driver(&tps6105x_driver);
}
subsys_initcall(tps6105x_init);

static void __exit tps6105x_exit(void)
{
        i2c_del_driver(&tps6105x_driver);
}
module_exit(tps6105x_exit);

MODULE_AUTHOR("Linus Walleij");
MODULE_DESCRIPTION("TPS6105x White LED Boost Converter Driver");
MODULE_LICENSE("GPL v2");