Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

[mirror_ubuntu-artful-kernel.git] / drivers / input / touchscreen / ad7879.c

/*
 * Copyright (C) 2008-2009 Michael Hennerich, Analog Devices Inc.
 *
 * Description: AD7879/AD7889 based touchscreen, and GPIO driver
 *              (I2C/SPI Interface)
 *
 * Bugs:        Enter bugs at http://blackfin.uclinux.org/
 *
 * 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, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * History:
 * Copyright (c) 2005 David Brownell
 * Copyright (c) 2006 Nokia Corporation
 * Various changes: Imre Deak <imre.deak@nokia.com>
 *
 * Using code from:
 *  - corgi_ts.c
 *      Copyright (C) 2004-2005 Richard Purdie
 *  - omap_ts.[hc], ads7846.h, ts_osk.c
 *      Copyright (C) 2002 MontaVista Software
 *      Copyright (C) 2004 Texas Instruments
 *      Copyright (C) 2005 Dirk Behme
 *  - ad7877.c
 *      Copyright (C) 2006-2008 Analog Devices Inc.
 */

#include <linux/device.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/spi/spi.h>
#include <linux/i2c.h>

#include <linux/spi/ad7879.h>

#define AD7879_REG_ZEROS                0
#define AD7879_REG_CTRL1                1
#define AD7879_REG_CTRL2                2
#define AD7879_REG_CTRL3                3
#define AD7879_REG_AUX1HIGH             4
#define AD7879_REG_AUX1LOW              5
#define AD7879_REG_TEMP1HIGH            6
#define AD7879_REG_TEMP1LOW             7
#define AD7879_REG_XPLUS                8
#define AD7879_REG_YPLUS                9
#define AD7879_REG_Z1                   10
#define AD7879_REG_Z2                   11
#define AD7879_REG_AUXVBAT              12
#define AD7879_REG_TEMP                 13
#define AD7879_REG_REVID                14

/* Control REG 1 */
#define AD7879_TMR(x)                   ((x & 0xFF) << 0)
#define AD7879_ACQ(x)                   ((x & 0x3) << 8)
#define AD7879_MODE_NOC                 (0 << 10)       /* Do not convert */
#define AD7879_MODE_SCC                 (1 << 10)       /* Single channel conversion */
#define AD7879_MODE_SEQ0                (2 << 10)       /* Sequence 0 in Slave Mode */
#define AD7879_MODE_SEQ1                (3 << 10)       /* Sequence 1 in Master Mode */
#define AD7879_MODE_INT                 (1 << 15)       /* PENIRQ disabled INT enabled */

/* Control REG 2 */
#define AD7879_FCD(x)                   ((x & 0x3) << 0)
#define AD7879_RESET                    (1 << 4)
#define AD7879_MFS(x)                   ((x & 0x3) << 5)
#define AD7879_AVG(x)                   ((x & 0x3) << 7)
#define AD7879_SER                      (1 << 9)        /* non-differential */
#define AD7879_DFR                      (0 << 9)        /* differential */
#define AD7879_GPIOPOL                  (1 << 10)
#define AD7879_GPIODIR                  (1 << 11)
#define AD7879_GPIO_DATA                (1 << 12)
#define AD7879_GPIO_EN                  (1 << 13)
#define AD7879_PM(x)                    ((x & 0x3) << 14)
#define AD7879_PM_SHUTDOWN              (0)
#define AD7879_PM_DYN                   (1)
#define AD7879_PM_FULLON                (2)

/* Control REG 3 */
#define AD7879_TEMPMASK_BIT             (1<<15)
#define AD7879_AUXVBATMASK_BIT          (1<<14)
#define AD7879_INTMODE_BIT              (1<<13)
#define AD7879_GPIOALERTMASK_BIT        (1<<12)
#define AD7879_AUXLOW_BIT               (1<<11)
#define AD7879_AUXHIGH_BIT              (1<<10)
#define AD7879_TEMPLOW_BIT              (1<<9)
#define AD7879_TEMPHIGH_BIT             (1<<8)
#define AD7879_YPLUS_BIT                (1<<7)
#define AD7879_XPLUS_BIT                (1<<6)
#define AD7879_Z1_BIT                   (1<<5)
#define AD7879_Z2_BIT                   (1<<4)
#define AD7879_AUX_BIT                  (1<<3)
#define AD7879_VBAT_BIT                 (1<<2)
#define AD7879_TEMP_BIT                 (1<<1)

enum {
        AD7879_SEQ_XPOS  = 0,
        AD7879_SEQ_YPOS  = 1,
        AD7879_SEQ_Z1    = 2,
        AD7879_SEQ_Z2    = 3,
        AD7879_NR_SENSE  = 4,
};

#define MAX_12BIT                       ((1<<12)-1)
#define TS_PEN_UP_TIMEOUT               msecs_to_jiffies(50)

#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
#define AD7879_DEVID            0x7A
typedef struct spi_device       bus_device;
#elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE)
#define AD7879_DEVID            0x79
typedef struct i2c_client       bus_device;
#endif

struct ad7879 {
        bus_device              *bus;
        struct input_dev        *input;
        struct work_struct      work;
        struct timer_list       timer;

        struct mutex            mutex;
        unsigned                disabled:1;     /* P: mutex */

#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
        struct spi_message      msg;
        struct spi_transfer     xfer[AD7879_NR_SENSE + 1];
        u16                     cmd;
#endif
        u16                     conversion_data[AD7879_NR_SENSE];
        char                    phys[32];
        u8                      first_conversion_delay;
        u8                      acquisition_time;
        u8                      averaging;
        u8                      pen_down_acc_interval;
        u8                      median;
        u16                     x_plate_ohms;
        u16                     pressure_max;
        u16                     gpio_init;
        u16                     cmd_crtl1;
        u16                     cmd_crtl2;
        u16                     cmd_crtl3;
        unsigned                gpio:1;
};

static int ad7879_read(bus_device *, u8);
static int ad7879_write(bus_device *, u8, u16);
static void ad7879_collect(struct ad7879 *);

static void ad7879_report(struct ad7879 *ts)
{
        struct input_dev *input_dev = ts->input;
        unsigned Rt;
        u16 x, y, z1, z2;

        x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
        y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
        z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
        z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;

        /*
         * The samples processed here are already preprocessed by the AD7879.
         * The preprocessing function consists of a median and an averaging filter.
         * The combination of these two techniques provides a robust solution,
         * discarding the spurious noise in the signal and keeping only the data of interest.
         * The size of both filters is programmable. (dev.platform_data, see linux/spi/ad7879.h)
         * Other user-programmable conversion controls include variable acquisition time,
         * and first conversion delay. Up to 16 averages can be taken per conversion.
         */

        if (likely(x && z1)) {
                /* compute touch pressure resistance using equation #1 */
                Rt = (z2 - z1) * x * ts->x_plate_ohms;
                Rt /= z1;
                Rt = (Rt + 2047) >> 12;

                input_report_abs(input_dev, ABS_X, x);
                input_report_abs(input_dev, ABS_Y, y);
                input_report_abs(input_dev, ABS_PRESSURE, Rt);
                input_sync(input_dev);
        }
}

static void ad7879_work(struct work_struct *work)
{
        struct ad7879 *ts = container_of(work, struct ad7879, work);

        /* use keventd context to read the result registers */
        ad7879_collect(ts);
        ad7879_report(ts);
        mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
}

static void ad7879_ts_event_release(struct ad7879 *ts)
{
        struct input_dev *input_dev = ts->input;

        input_report_abs(input_dev, ABS_PRESSURE, 0);
        input_sync(input_dev);
}

static void ad7879_timer(unsigned long handle)
{
        struct ad7879 *ts = (void *)handle;

        ad7879_ts_event_release(ts);
}

static irqreturn_t ad7879_irq(int irq, void *handle)
{
        struct ad7879 *ts = handle;

        /* The repeated conversion sequencer controlled by TMR kicked off too fast.
         * We ignore the last and process the sample sequence currently in the queue.
         * It can't be older than 9.4ms
         */

        if (!work_pending(&ts->work))
                schedule_work(&ts->work);

        return IRQ_HANDLED;
}

static void ad7879_setup(struct ad7879 *ts)
{
        ts->cmd_crtl3 = AD7879_YPLUS_BIT |
                        AD7879_XPLUS_BIT |
                        AD7879_Z2_BIT |
                        AD7879_Z1_BIT |
                        AD7879_TEMPMASK_BIT |
                        AD7879_AUXVBATMASK_BIT |
                        AD7879_GPIOALERTMASK_BIT;

        ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
                        AD7879_AVG(ts->averaging) |
                        AD7879_MFS(ts->median) |
                        AD7879_FCD(ts->first_conversion_delay) |
                        ts->gpio_init;

        ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
                        AD7879_ACQ(ts->acquisition_time) |
                        AD7879_TMR(ts->pen_down_acc_interval);

        ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
        ad7879_write(ts->bus, AD7879_REG_CTRL3, ts->cmd_crtl3);
        ad7879_write(ts->bus, AD7879_REG_CTRL1, ts->cmd_crtl1);
}

static void ad7879_disable(struct ad7879 *ts)
{
        mutex_lock(&ts->mutex);

        if (!ts->disabled) {

                ts->disabled = 1;
                disable_irq(ts->bus->irq);

                cancel_work_sync(&ts->work);

                if (del_timer_sync(&ts->timer))
                        ad7879_ts_event_release(ts);

                ad7879_write(ts->bus, AD7879_REG_CTRL2,
                             AD7879_PM(AD7879_PM_SHUTDOWN));
        }

        mutex_unlock(&ts->mutex);
}

static void ad7879_enable(struct ad7879 *ts)
{
        mutex_lock(&ts->mutex);

        if (ts->disabled) {
                ad7879_setup(ts);
                ts->disabled = 0;
                enable_irq(ts->bus->irq);
        }

        mutex_unlock(&ts->mutex);
}

static ssize_t ad7879_disable_show(struct device *dev,
                                     struct device_attribute *attr, char *buf)
{
        struct ad7879 *ts = dev_get_drvdata(dev);

        return sprintf(buf, "%u\n", ts->disabled);
}

static ssize_t ad7879_disable_store(struct device *dev,
                                     struct device_attribute *attr,
                                     const char *buf, size_t count)
{
        struct ad7879 *ts = dev_get_drvdata(dev);
        unsigned long val;
        int error;

        error = strict_strtoul(buf, 10, &val);
        if (error)
                return error;

        if (val)
                ad7879_disable(ts);
        else
                ad7879_enable(ts);

        return count;
}

static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);

static ssize_t ad7879_gpio_show(struct device *dev,
                                     struct device_attribute *attr, char *buf)
{
        struct ad7879 *ts = dev_get_drvdata(dev);

        return sprintf(buf, "%u\n", ts->gpio);
}

static ssize_t ad7879_gpio_store(struct device *dev,
                                     struct device_attribute *attr,
                                     const char *buf, size_t count)
{
        struct ad7879 *ts = dev_get_drvdata(dev);
        unsigned long val;
        int error;

        error = strict_strtoul(buf, 10, &val);
        if (error)
                return error;

        mutex_lock(&ts->mutex);
        ts->gpio = !!val;
        error = ad7879_write(ts->bus, AD7879_REG_CTRL2,
                           ts->gpio ?
                                ts->cmd_crtl2 & ~AD7879_GPIO_DATA :
                                ts->cmd_crtl2 | AD7879_GPIO_DATA);
        mutex_unlock(&ts->mutex);

        return error ? : count;
}

static DEVICE_ATTR(gpio, 0664, ad7879_gpio_show, ad7879_gpio_store);

static struct attribute *ad7879_attributes[] = {
        &dev_attr_disable.attr,
        &dev_attr_gpio.attr,
        NULL
};

static const struct attribute_group ad7879_attr_group = {
        .attrs = ad7879_attributes,
};

static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
{
        struct input_dev *input_dev;
        struct ad7879_platform_data *pdata = bus->dev.platform_data;
        int err;
        u16 revid;

        if (!bus->irq) {
                dev_err(&bus->dev, "no IRQ?\n");
                return -ENODEV;
        }

        if (!pdata) {
                dev_err(&bus->dev, "no platform data?\n");
                return -ENODEV;
        }

        input_dev = input_allocate_device();
        if (!input_dev)
                return -ENOMEM;

        ts->input = input_dev;

        setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
        INIT_WORK(&ts->work, ad7879_work);
        mutex_init(&ts->mutex);

        ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
        ts->pressure_max = pdata->pressure_max ? : ~0;

        ts->first_conversion_delay = pdata->first_conversion_delay;
        ts->acquisition_time = pdata->acquisition_time;
        ts->averaging = pdata->averaging;
        ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
        ts->median = pdata->median;

        if (pdata->gpio_output)
                ts->gpio_init = AD7879_GPIO_EN |
                                (pdata->gpio_default ? 0 : AD7879_GPIO_DATA);
        else
                ts->gpio_init = AD7879_GPIO_EN | AD7879_GPIODIR;

        snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&bus->dev));

        input_dev->name = "AD7879 Touchscreen";
        input_dev->phys = ts->phys;
        input_dev->dev.parent = &bus->dev;

        __set_bit(EV_ABS, input_dev->evbit);
        __set_bit(ABS_X, input_dev->absbit);
        __set_bit(ABS_Y, input_dev->absbit);
        __set_bit(ABS_PRESSURE, input_dev->absbit);

        input_set_abs_params(input_dev, ABS_X,
                        pdata->x_min ? : 0,
                        pdata->x_max ? : MAX_12BIT,
                        0, 0);
        input_set_abs_params(input_dev, ABS_Y,
                        pdata->y_min ? : 0,
                        pdata->y_max ? : MAX_12BIT,
                        0, 0);
        input_set_abs_params(input_dev, ABS_PRESSURE,
                        pdata->pressure_min, pdata->pressure_max, 0, 0);

        err = ad7879_write(bus, AD7879_REG_CTRL2, AD7879_RESET);

        if (err < 0) {
                dev_err(&bus->dev, "Failed to write %s\n", input_dev->name);
                goto err_free_mem;
        }

        revid = ad7879_read(bus, AD7879_REG_REVID);

        if ((revid & 0xFF) != AD7879_DEVID) {
                dev_err(&bus->dev, "Failed to probe %s\n", input_dev->name);
                err = -ENODEV;
                goto err_free_mem;
        }

        ad7879_setup(ts);

        err = request_irq(bus->irq, ad7879_irq,
                          IRQF_TRIGGER_FALLING, bus->dev.driver->name, ts);

        if (err) {
                dev_err(&bus->dev, "irq %d busy?\n", bus->irq);
                goto err_free_mem;
        }

        err = sysfs_create_group(&bus->dev.kobj, &ad7879_attr_group);
        if (err)
                goto err_free_irq;

        err = input_register_device(input_dev);
        if (err)
                goto err_remove_attr;

        dev_info(&bus->dev, "Rev.%d touchscreen, irq %d\n",
                 revid >> 8, bus->irq);

        return 0;

err_remove_attr:
        sysfs_remove_group(&bus->dev.kobj, &ad7879_attr_group);
err_free_irq:
        free_irq(bus->irq, ts);
err_free_mem:
        input_free_device(input_dev);

        return err;
}

static int __devexit ad7879_destroy(bus_device *bus, struct ad7879 *ts)
{
        ad7879_disable(ts);
        sysfs_remove_group(&ts->bus->dev.kobj, &ad7879_attr_group);
        free_irq(ts->bus->irq, ts);
        input_unregister_device(ts->input);
        dev_dbg(&bus->dev, "unregistered touchscreen\n");

        return 0;
}

#ifdef CONFIG_PM
static int ad7879_suspend(bus_device *bus, pm_message_t message)
{
        struct ad7879 *ts = dev_get_drvdata(&bus->dev);

        ad7879_disable(ts);

        return 0;
}

static int ad7879_resume(bus_device *bus)
{
        struct ad7879 *ts = dev_get_drvdata(&bus->dev);

        ad7879_enable(ts);

        return 0;
}
#else
#define ad7879_suspend NULL
#define ad7879_resume  NULL
#endif

#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
#define MAX_SPI_FREQ_HZ         5000000
#define AD7879_CMD_MAGIC        0xE000
#define AD7879_CMD_READ         (1 << 10)
#define AD7879_WRITECMD(reg)    (AD7879_CMD_MAGIC | (reg & 0xF))
#define AD7879_READCMD(reg)     (AD7879_CMD_MAGIC | AD7879_CMD_READ | (reg & 0xF))

struct ser_req {
        u16                     command;
        u16                     data;
        struct spi_message      msg;
        struct spi_transfer     xfer[2];
};

/*
 * ad7879_read/write are only used for initial setup and for sysfs controls.
 * The main traffic is done in ad7879_collect().
 */

static int ad7879_read(struct spi_device *spi, u8 reg)
{
        struct ser_req *req;
        int status, ret;

        req = kzalloc(sizeof *req, GFP_KERNEL);
        if (!req)
                return -ENOMEM;

        spi_message_init(&req->msg);

        req->command = (u16) AD7879_READCMD(reg);
        req->xfer[0].tx_buf = &req->command;
        req->xfer[0].len = 2;

        req->xfer[1].rx_buf = &req->data;
        req->xfer[1].len = 2;

        spi_message_add_tail(&req->xfer[0], &req->msg);
        spi_message_add_tail(&req->xfer[1], &req->msg);

        status = spi_sync(spi, &req->msg);
        ret = status ? : req->data;

        kfree(req);

        return ret;
}

static int ad7879_write(struct spi_device *spi, u8 reg, u16 val)
{
        struct ser_req *req;
        int status;

        req = kzalloc(sizeof *req, GFP_KERNEL);
        if (!req)
                return -ENOMEM;

        spi_message_init(&req->msg);

        req->command = (u16) AD7879_WRITECMD(reg);
        req->xfer[0].tx_buf = &req->command;
        req->xfer[0].len = 2;

        req->data = val;
        req->xfer[1].tx_buf = &req->data;
        req->xfer[1].len = 2;

        spi_message_add_tail(&req->xfer[0], &req->msg);
        spi_message_add_tail(&req->xfer[1], &req->msg);

        status = spi_sync(spi, &req->msg);

        kfree(req);

        return status;
}

static void ad7879_collect(struct ad7879 *ts)
{
        int status = spi_sync(ts->bus, &ts->msg);

        if (status)
                dev_err(&ts->bus->dev, "spi_sync --> %d\n", status);
}

static void ad7879_setup_ts_def_msg(struct ad7879 *ts)
{
        struct spi_message *m;
        int i;

        ts->cmd = (u16) AD7879_READCMD(AD7879_REG_XPLUS);

        m = &ts->msg;
        spi_message_init(m);
        ts->xfer[0].tx_buf = &ts->cmd;
        ts->xfer[0].len = 2;

        spi_message_add_tail(&ts->xfer[0], m);

        for (i = 0; i < AD7879_NR_SENSE; i++) {
                ts->xfer[i + 1].rx_buf = &ts->conversion_data[i];
                ts->xfer[i + 1].len = 2;
                spi_message_add_tail(&ts->xfer[i + 1], m);
        }
}

static int __devinit ad7879_probe(struct spi_device *spi)
{
        struct ad7879 *ts;
        int error;

        /* don't exceed max specified SPI CLK frequency */
        if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
                dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
                return -EINVAL;
        }

        ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
        if (!ts)
                return -ENOMEM;

        dev_set_drvdata(&spi->dev, ts);
        ts->bus = spi;

        ad7879_setup_ts_def_msg(ts);

        error = ad7879_construct(spi, ts);
        if (error) {
                dev_set_drvdata(&spi->dev, NULL);
                kfree(ts);
        }

        return error;
}

static int __devexit ad7879_remove(struct spi_device *spi)
{
        struct ad7879 *ts = dev_get_drvdata(&spi->dev);

        ad7879_destroy(spi, ts);
        dev_set_drvdata(&spi->dev, NULL);
        kfree(ts);

        return 0;
}

static struct spi_driver ad7879_driver = {
        .driver = {
                .name   = "ad7879",
                .bus    = &spi_bus_type,
                .owner  = THIS_MODULE,
        },
        .probe          = ad7879_probe,
        .remove         = __devexit_p(ad7879_remove),
        .suspend        = ad7879_suspend,
        .resume         = ad7879_resume,
};

static int __init ad7879_init(void)
{
        return spi_register_driver(&ad7879_driver);
}
module_init(ad7879_init);

static void __exit ad7879_exit(void)
{
        spi_unregister_driver(&ad7879_driver);
}
module_exit(ad7879_exit);

#elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE)

/* All registers are word-sized.
 * AD7879 uses a high-byte first convention.
 */
static int ad7879_read(struct i2c_client *client, u8 reg)
{
        return swab16(i2c_smbus_read_word_data(client, reg));
}

static int ad7879_write(struct i2c_client *client, u8 reg, u16 val)
{
        return i2c_smbus_write_word_data(client, reg, swab16(val));
}

static void ad7879_collect(struct ad7879 *ts)
{
        int i;

        for (i = 0; i < AD7879_NR_SENSE; i++)
                ts->conversion_data[i] = ad7879_read(ts->bus,
                                                     AD7879_REG_XPLUS + i);
}

static int __devinit ad7879_probe(struct i2c_client *client,
                                        const struct i2c_device_id *id)
{
        struct ad7879 *ts;
        int error;

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

        ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
        if (!ts)
                return -ENOMEM;

        i2c_set_clientdata(client, ts);
        ts->bus = client;

        error = ad7879_construct(client, ts);
        if (error) {
                i2c_set_clientdata(client, NULL);
                kfree(ts);
        }

        return error;
}

static int __devexit ad7879_remove(struct i2c_client *client)
{
        struct ad7879 *ts = dev_get_drvdata(&client->dev);

        ad7879_destroy(client, ts);
        i2c_set_clientdata(client, NULL);
        kfree(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_driver = {
        .driver = {
                .name   = "ad7879",
                .owner  = THIS_MODULE,
        },
        .probe          = ad7879_probe,
        .remove         = __devexit_p(ad7879_remove),
        .suspend        = ad7879_suspend,
        .resume         = ad7879_resume,
        .id_table       = ad7879_id,
};

static int __init ad7879_init(void)
{
        return i2c_add_driver(&ad7879_driver);
}
module_init(ad7879_init);

static void __exit ad7879_exit(void)
{
        i2c_del_driver(&ad7879_driver);
}
module_exit(ad7879_exit);
#endif

MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:ad7879");