ad7879-i2c.c

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/*
 * AD7879-1/AD7889-1 touchscreen (I2C bus)
 *
 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/input.h>    /* BUS_I2C */
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/pm.h>

#include "ad7879.h"

#define AD7879_DEVID        0x79    /* AD7879-1/AD7889-1 */

/* All registers are word-sized.
 * AD7879 uses a high-byte first convention.
 */
static int ad7879_i2c_read(struct device *dev, u8 reg)
{
    struct i2c_client *client = to_i2c_client(dev);

    return i2c_smbus_read_word_swapped(client, reg);
}

static int ad7879_i2c_multi_read(struct device *dev,
                 u8 first_reg, u8 count, u16 *buf)
{
    struct i2c_client *client = to_i2c_client(dev);
    u8 idx;

    i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf);

    for (idx = 0; idx < count; ++idx)
        buf[idx] = swab16(buf[idx]);

    return 0;
}

static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
{
    struct i2c_client *client = to_i2c_client(dev);

    return i2c_smbus_write_word_swapped(client, reg, val);
}

static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
    .bustype    = BUS_I2C,
    .read       = ad7879_i2c_read,
    .multi_read = ad7879_i2c_multi_read,
    .write      = ad7879_i2c_write,
};

static int __devinit ad7879_i2c_probe(struct i2c_client *client,
                      const struct i2c_device_id *id)
{
    struct ad7879 *ts;

    if (!i2c_check_functionality(client->adapter,
                     I2C_FUNC_SMBUS_WORD_DATA)) {
        dev_err(&client->dev, "SMBUS Word Data not Supported\n");
        return -EIO;
    }

    ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
              &ad7879_i2c_bus_ops);
    if (IS_ERR(ts))
        return PTR_ERR(ts);

    i2c_set_clientdata(client, ts);

    return 0;
}

static int __devexit ad7879_i2c_remove(struct i2c_client *client)
{
    struct ad7879 *ts = i2c_get_clientdata(client);

    ad7879_remove(ts);

    return 0;
}

static const struct i2c_device_id ad7879_id[] = {
    { "ad7879", 0 },
    { "ad7889", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, ad7879_id);

static struct i2c_driver ad7879_i2c_driver = {
    .driver = {
        .name   = "ad7879",
        .owner  = THIS_MODULE,
        .pm = &ad7879_pm_ops,
    },
    .probe      = ad7879_i2c_probe,
    .remove     = __devexit_p(ad7879_i2c_remove),
    .id_table   = ad7879_id,
};

module_i2c_driver(ad7879_i2c_driver);

MODULE_AUTHOR("Michael Hennerich <[email protected]>");
MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
MODULE_LICENSE("GPL");