/*
 * TSC2005 touchscreen driver
 *
 * Copyright (C) 2006-2010 Nokia Corporation
 *
 * Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
 * based on TSC2301 driver by Klaus K. Pedersen <klaus.k.pedersen@nokia.com>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/spi/spi.h>
#include <linux/spi/tsc2005.h>

/*
 * The touchscreen interface operates as follows:
 *
 * 1) Pen is pressed against the touchscreen.
 * 2) TSC2005 performs AD conversion.
 * 3) After the conversion is done TSC2005 drives DAV line down.
 * 4) GPIO IRQ is received and tsc2005_irq_thread() is scheduled.
 * 5) tsc2005_irq_thread() queues up an spi transfer to fetch the x, y, z1, z2
 *    values.
 * 6) tsc2005_irq_thread() reports coordinates to input layer and sets up
 *    tsc2005_penup_timer() to be called after TSC2005_PENUP_TIME_MS (40ms).
 * 7) When the penup timer expires, there have not been touch or DAV interrupts
 *    during the last 40ms which means the pen has been lifted.
 *
 * ESD recovery via a hardware reset is done if the TSC2005 doesn't respond
 * after a configurable period (in ms) of activity. If esd_timeout is 0, the
 * watchdog is disabled.
 */

/* control byte 1 */
#define TSC2005_CMD                     0x80
#define TSC2005_CMD_NORMAL              0x00
#define TSC2005_CMD_STOP                0x01
#define TSC2005_CMD_12BIT               0x04

/* control byte 0 */
#define TSC2005_REG_READ                0x0001
#define TSC2005_REG_PND0                0x0002
#define TSC2005_REG_X                   0x0000
#define TSC2005_REG_Y                   0x0008
#define TSC2005_REG_Z1                  0x0010
#define TSC2005_REG_Z2                  0x0018
#define TSC2005_REG_TEMP_HIGH           0x0050
#define TSC2005_REG_CFR0                0x0060
#define TSC2005_REG_CFR1                0x0068
#define TSC2005_REG_CFR2                0x0070

/* configuration register 0 */
#define TSC2005_CFR0_PRECHARGE_276US    0x0040
#define TSC2005_CFR0_STABTIME_1MS       0x0300
#define TSC2005_CFR0_CLOCK_1MHZ         0x1000
#define TSC2005_CFR0_RESOLUTION12       0x2000
#define TSC2005_CFR0_PENMODE            0x8000
#define TSC2005_CFR0_INITVALUE          (TSC2005_CFR0_STABTIME_1MS    | \
                                         TSC2005_CFR0_CLOCK_1MHZ      | \
                                         TSC2005_CFR0_RESOLUTION12    | \
                                         TSC2005_CFR0_PRECHARGE_276US | \
                                         TSC2005_CFR0_PENMODE)

/* bits common to both read and write of configuration register 0 */
#define TSC2005_CFR0_RW_MASK            0x3fff

/* configuration register 1 */
#define TSC2005_CFR1_BATCHDELAY_4MS     0x0003
#define TSC2005_CFR1_INITVALUE          TSC2005_CFR1_BATCHDELAY_4MS

/* configuration register 2 */
#define TSC2005_CFR2_MAVE_Z             0x0004
#define TSC2005_CFR2_MAVE_Y             0x0008
#define TSC2005_CFR2_MAVE_X             0x0010
#define TSC2005_CFR2_AVG_7              0x0800
#define TSC2005_CFR2_MEDIUM_15          0x3000
#define TSC2005_CFR2_INITVALUE          (TSC2005_CFR2_MAVE_X    | \
                                         TSC2005_CFR2_MAVE_Y    | \
                                         TSC2005_CFR2_MAVE_Z    | \
                                         TSC2005_CFR2_MEDIUM_15 | \
                                         TSC2005_CFR2_AVG_7)

#define MAX_12BIT                       0xfff
#define TSC2005_SPI_MAX_SPEED_HZ        10000000
#define TSC2005_PENUP_TIME_MS           40

struct tsc2005_spi_rd {
        struct spi_transfer     spi_xfer;
        u32                     spi_tx;
        u32                     spi_rx;
};

struct tsc2005 {
        struct spi_device       *spi;

        struct spi_message      spi_read_msg;
        struct tsc2005_spi_rd   spi_x;
        struct tsc2005_spi_rd   spi_y;
        struct tsc2005_spi_rd   spi_z1;
        struct tsc2005_spi_rd   spi_z2;

        struct input_dev        *idev;
        char                    phys[32];

        struct mutex            mutex;

        /* raw copy of previous x,y,z */
        int                     in_x;
        int                     in_y;
        int                     in_z1;
        int                     in_z2;

        spinlock_t              lock;
        struct timer_list       penup_timer;

        unsigned int            esd_timeout;
        struct delayed_work     esd_work;
        unsigned long           last_valid_interrupt;

        unsigned int            x_plate_ohm;

        bool                    opened;
        bool                    suspended;

        bool                    pen_down;

        void                    (*set_reset)(bool enable);
};

static int tsc2005_cmd(struct tsc2005 *ts, u8 cmd)
{
        u8 tx = TSC2005_CMD | TSC2005_CMD_12BIT | cmd;
        struct spi_transfer xfer = {
                .tx_buf         = &tx,
                .len            = 1,
                .bits_per_word  = 8,
        };
        struct spi_message msg;
        int error;

        spi_message_init(&msg);
        spi_message_add_tail(&xfer, &msg);

        error = spi_sync(ts->spi, &msg);
        if (error) {
                dev_err(&ts->spi->dev, "%s: failed, command: %x, error: %d\n",
                        __func__, cmd, error);
                return error;
        }

        return 0;
}

static int tsc2005_write(struct tsc2005 *ts, u8 reg, u16 value)
{
        u32 tx = ((reg | TSC2005_REG_PND0) << 16) | value;
        struct spi_transfer xfer = {
                .tx_buf         = &tx,
                .len            = 4,
                .bits_per_word  = 24,
        };
        struct spi_message msg;
        int error;

        spi_message_init(&msg);
        spi_message_add_tail(&xfer, &msg);

        error = spi_sync(ts->spi, &msg);
        if (error) {
                dev_err(&ts->spi->dev,
                        "%s: failed, register: %x, value: %x, error: %d\n",
                        __func__, reg, value, error);
                return error;
        }

        return 0;
}

static void tsc2005_setup_read(struct tsc2005_spi_rd *rd, u8 reg, bool last)
{
        memset(rd, 0, sizeof(*rd));

        rd->spi_tx                 = (reg | TSC2005_REG_READ) << 16;
        rd->spi_xfer.tx_buf        = &rd->spi_tx;
        rd->spi_xfer.rx_buf        = &rd->spi_rx;
        rd->spi_xfer.len           = 4;
        rd->spi_xfer.bits_per_word = 24;
        rd->spi_xfer.cs_change     = !last;
}

static int tsc2005_read(struct tsc2005 *ts, u8 reg, u16 *value)
{
        struct tsc2005_spi_rd spi_rd;
        struct spi_message msg;
        int error;

        tsc2005_setup_read(&spi_rd, reg, true);

        spi_message_init(&msg);
        spi_message_add_tail(&spi_rd.spi_xfer, &msg);

        error = spi_sync(ts->spi, &msg);
        if (error)
                return error;

        *value = spi_rd.spi_rx;
        return 0;
}

static void tsc2005_update_pen_state(struct tsc2005 *ts,
                                     int x, int y, int pressure)
{
        if (pressure) {
                input_report_abs(ts->idev, ABS_X, x);
                input_report_abs(ts->idev, ABS_Y, y);
                input_report_abs(ts->idev, ABS_PRESSURE, pressure);
                if (!ts->pen_down) {
                        input_report_key(ts->idev, BTN_TOUCH, !!pressure);
                        ts->pen_down = true;
                }
        } else {
                input_report_abs(ts->idev, ABS_PRESSURE, 0);
                if (ts->pen_down) {
                        input_report_key(ts->idev, BTN_TOUCH, 0);
                        ts->pen_down = false;
                }
        }
        input_sync(ts->idev);
        dev_dbg(&ts->spi->dev, "point(%4d,%4d), pressure (%4d)\n", x, y,
                pressure);
}

static irqreturn_t tsc2005_irq_thread(int irq, void *_ts)
{
        struct tsc2005 *ts = _ts;
        unsigned long flags;
        unsigned int pressure;
        u32 x, y;
        u32 z1, z2;
        int error;

        /* read the coordinates */
        error = spi_sync(ts->spi, &ts->spi_read_msg);
        if (unlikely(error))
                goto out;

        x = ts->spi_x.spi_rx;
        y = ts->spi_y.spi_rx;
        z1 = ts->spi_z1.spi_rx;
        z2 = ts->spi_z2.spi_rx;

        /* validate position */
        if (unlikely(x > MAX_12BIT || y > MAX_12BIT))
                goto out;

        /* Skip reading if the pressure components are out of range */
        if (unlikely(z1 == 0 || z2 > MAX_12BIT || z1 >= z2))
                goto out;

       /*
        * Skip point if this is a pen down with the exact same values as
        * the value before pen-up - that implies SPI fed us stale data
        */
        if (!ts->pen_down &&
            ts->in_x == x && ts->in_y == y &&
            ts->in_z1 == z1 && ts->in_z2 == z2) {
                goto out;
        }

        /*
         * At this point we are happy we have a valid and useful reading.
         * Remember it for later comparisons. We may now begin downsampling.
         */
        ts->in_x = x;
        ts->in_y = y;
        ts->in_z1 = z1;
        ts->in_z2 = z2;

        /* Compute touch pressure resistance using equation #1 */
        pressure = x * (z2 - z1) / z1;
        pressure = pressure * ts->x_plate_ohm / 4096;
        if (unlikely(pressure > MAX_12BIT))
                goto out;

        spin_lock_irqsave(&ts->lock, flags);

        tsc2005_update_pen_state(ts, x, y, pressure);
        mod_timer(&ts->penup_timer,
                  jiffies + msecs_to_jiffies(TSC2005_PENUP_TIME_MS));

        spin_unlock_irqrestore(&ts->lock, flags);

        ts->last_valid_interrupt = jiffies;
out:
        return IRQ_HANDLED;
}

static void tsc2005_penup_timer(unsigned long data)
{
        struct tsc2005 *ts = (struct tsc2005 *)data;
        unsigned long flags;

        spin_lock_irqsave(&ts->lock, flags);
        tsc2005_update_pen_state(ts, 0, 0, 0);
        spin_unlock_irqrestore(&ts->lock, flags);
}

static void tsc2005_start_scan(struct tsc2005 *ts)
{
        tsc2005_write(ts, TSC2005_REG_CFR0, TSC2005_CFR0_INITVALUE);
        tsc2005_write(ts, TSC2005_REG_CFR1, TSC2005_CFR1_INITVALUE);
        tsc2005_write(ts, TSC2005_REG_CFR2, TSC2005_CFR2_INITVALUE);
        tsc2005_cmd(ts, TSC2005_CMD_NORMAL);
}

static void tsc2005_stop_scan(struct tsc2005 *ts)
{
        tsc2005_cmd(ts, TSC2005_CMD_STOP);
}

/* must be called with ts->mutex held */
static void __tsc2005_disable(struct tsc2005 *ts)
{
        tsc2005_stop_scan(ts);

        disable_irq(ts->spi->irq);
        del_timer_sync(&ts->penup_timer);

        cancel_delayed_work_sync(&ts->esd_work);

        enable_irq(ts->spi->irq);
}

/* must be called with ts->mutex held */
static void __tsc2005_enable(struct tsc2005 *ts)
{
        tsc2005_start_scan(ts);

        if (ts->esd_timeout && ts->set_reset) {
                ts->last_valid_interrupt = jiffies;
                schedule_delayed_work(&ts->esd_work,
                                round_jiffies_relative(
                                        msecs_to_jiffies(ts->esd_timeout)));
        }

}

static ssize_t tsc2005_selftest_show(struct device *dev,
                                     struct device_attribute *attr,
                                     char *buf)
{
        struct spi_device *spi = to_spi_device(dev);
        struct tsc2005 *ts = spi_get_drvdata(spi);
        u16 temp_high;
        u16 temp_high_orig;
        u16 temp_high_test;
        bool success = true;
        int error;

        mutex_lock(&ts->mutex);

        /*
         * Test TSC2005 communications via temp high register.
         */
        __tsc2005_disable(ts);

        error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high_orig);
        if (error) {
                dev_warn(dev, "selftest failed: read error %d\n", error);
                success = false;
                goto out;
        }

        temp_high_test = (temp_high_orig - 1) & MAX_12BIT;

        error = tsc2005_write(ts, TSC2005_REG_TEMP_HIGH, temp_high_test);
        if (error) {
                dev_warn(dev, "selftest failed: write error %d\n", error);
                success = false;
                goto out;
        }

        error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high);
        if (error) {
                dev_warn(dev, "selftest failed: read error %d after write\n",
                         error);
                success = false;
                goto out;
        }

        if (temp_high != temp_high_test) {
                dev_warn(dev, "selftest failed: %d != %d\n",
                         temp_high, temp_high_test);
                success = false;
        }

        /* hardware reset */
        ts->set_reset(false);
        usleep_range(100, 500); /* only 10us required */
        ts->set_reset(true);

        if (!success)
                goto out;

        /* test that the reset really happened */
        error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high);
        if (error) {
                dev_warn(dev, "selftest failed: read error %d after reset\n",
                         error);
                success = false;
                goto out;
        }

        if (temp_high != temp_high_orig) {
                dev_warn(dev, "selftest failed after reset: %d != %d\n",
                         temp_high, temp_high_orig);
                success = false;
        }

out:
        __tsc2005_enable(ts);
        mutex_unlock(&ts->mutex);

        return sprintf(buf, "%d\n", success);
}

static DEVICE_ATTR(selftest, S_IRUGO, tsc2005_selftest_show, NULL);

static struct attribute *tsc2005_attrs[] = {
        &dev_attr_selftest.attr,
        NULL
};

static umode_t tsc2005_attr_is_visible(struct kobject *kobj,
                                      struct attribute *attr, int n)
{
        struct device *dev = container_of(kobj, struct device, kobj);
        struct spi_device *spi = to_spi_device(dev);
        struct tsc2005 *ts = spi_get_drvdata(spi);
        umode_t mode = attr->mode;

        if (attr == &dev_attr_selftest.attr) {
                if (!ts->set_reset)
                        mode = 0;
        }

        return mode;
}

static const struct attribute_group tsc2005_attr_group = {
        .is_visible     = tsc2005_attr_is_visible,
        .attrs          = tsc2005_attrs,
};

static void tsc2005_esd_work(struct work_struct *work)
{
        struct tsc2005 *ts = container_of(work, struct tsc2005, esd_work.work);
        int error;
        u16 r;

        if (!mutex_trylock(&ts->mutex)) {
                /*
                 * If the mutex is taken, it means that disable or enable is in
                 * progress. In that case just reschedule the work. If the work
                 * is not needed, it will be canceled by disable.
                 */
                goto reschedule;
        }

        if (time_is_after_jiffies(ts->last_valid_interrupt +
                                  msecs_to_jiffies(ts->esd_timeout)))
                goto out;

        /* We should be able to read register without disabling interrupts. */
        error = tsc2005_read(ts, TSC2005_REG_CFR0, &r);
        if (!error &&
            !((r ^ TSC2005_CFR0_INITVALUE) & TSC2005_CFR0_RW_MASK)) {
                goto out;
        }

        /*
         * If we could not read our known value from configuration register 0
         * then we should reset the controller as if from power-up and start
         * scanning again.
         */
        dev_info(&ts->spi->dev, "TSC2005 not responding - resetting\n");

        disable_irq(ts->spi->irq);
        del_timer_sync(&ts->penup_timer);

        tsc2005_update_pen_state(ts, 0, 0, 0);

        ts->set_reset(false);
        usleep_range(100, 500); /* only 10us required */
        ts->set_reset(true);

        enable_irq(ts->spi->irq);
        tsc2005_start_scan(ts);

out:
        mutex_unlock(&ts->mutex);
reschedule:
        /* re-arm the watchdog */
        schedule_delayed_work(&ts->esd_work,
                              round_jiffies_relative(
                                        msecs_to_jiffies(ts->esd_timeout)));
}

static int tsc2005_open(struct input_dev *input)
{
        struct tsc2005 *ts = input_get_drvdata(input);

        mutex_lock(&ts->mutex);

        if (!ts->suspended)
                __tsc2005_enable(ts);

        ts->opened = true;

        mutex_unlock(&ts->mutex);

        return 0;
}

static void tsc2005_close(struct input_dev *input)
{
        struct tsc2005 *ts = input_get_drvdata(input);

        mutex_lock(&ts->mutex);

        if (!ts->suspended)
                __tsc2005_disable(ts);

        ts->opened = false;

        mutex_unlock(&ts->mutex);
}

static void tsc2005_setup_spi_xfer(struct tsc2005 *ts)
{
        tsc2005_setup_read(&ts->spi_x, TSC2005_REG_X, false);
        tsc2005_setup_read(&ts->spi_y, TSC2005_REG_Y, false);
        tsc2005_setup_read(&ts->spi_z1, TSC2005_REG_Z1, false);
        tsc2005_setup_read(&ts->spi_z2, TSC2005_REG_Z2, true);

        spi_message_init(&ts->spi_read_msg);
        spi_message_add_tail(&ts->spi_x.spi_xfer, &ts->spi_read_msg);
        spi_message_add_tail(&ts->spi_y.spi_xfer, &ts->spi_read_msg);
        spi_message_add_tail(&ts->spi_z1.spi_xfer, &ts->spi_read_msg);
        spi_message_add_tail(&ts->spi_z2.spi_xfer, &ts->spi_read_msg);
}

static int tsc2005_probe(struct spi_device *spi)
{
        const struct tsc2005_platform_data *pdata = spi->dev.platform_data;
        struct tsc2005 *ts;
        struct input_dev *input_dev;
        unsigned int max_x, max_y, max_p;
        unsigned int fudge_x, fudge_y, fudge_p;
        int error;

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

        fudge_x = pdata->ts_x_fudge        ? : 4;
        fudge_y = pdata->ts_y_fudge        ? : 8;
        fudge_p = pdata->ts_pressure_fudge ? : 2;
        max_x   = pdata->ts_x_max          ? : MAX_12BIT;
        max_y   = pdata->ts_y_max          ? : MAX_12BIT;
        max_p   = pdata->ts_pressure_max   ? : MAX_12BIT;

        if (spi->irq <= 0) {
                dev_dbg(&spi->dev, "no irq\n");
                return -ENODEV;
        }

        spi->mode = SPI_MODE_0;
        spi->bits_per_word = 8;
        if (!spi->max_speed_hz)
                spi->max_speed_hz = TSC2005_SPI_MAX_SPEED_HZ;

        error = spi_setup(spi);
        if (error)
                return error;

        ts = kzalloc(sizeof(*ts), GFP_KERNEL);
        input_dev = input_allocate_device();
        if (!ts || !input_dev) {
                error = -ENOMEM;
                goto err_free_mem;
        }

        ts->spi = spi;
        ts->idev = input_dev;

        ts->x_plate_ohm = pdata->ts_x_plate_ohm ? : 280;
        ts->esd_timeout = pdata->esd_timeout_ms;
        ts->set_reset   = pdata->set_reset;

        mutex_init(&ts->mutex);

        spin_lock_init(&ts->lock);
        setup_timer(&ts->penup_timer, tsc2005_penup_timer, (unsigned long)ts);

        INIT_DELAYED_WORK(&ts->esd_work, tsc2005_esd_work);

        tsc2005_setup_spi_xfer(ts);

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

        input_dev->name = "TSC2005 touchscreen";
        input_dev->phys = ts->phys;
        input_dev->id.bustype = BUS_SPI;
        input_dev->dev.parent = &spi->dev;
        input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

        input_set_abs_params(input_dev, ABS_X, 0, max_x, fudge_x, 0);
        input_set_abs_params(input_dev, ABS_Y, 0, max_y, fudge_y, 0);
        input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);

        input_dev->open = tsc2005_open;
        input_dev->close = tsc2005_close;

        input_set_drvdata(input_dev, ts);

        /* Ensure the touchscreen is off */
        tsc2005_stop_scan(ts);

        error = request_threaded_irq(spi->irq, NULL, tsc2005_irq_thread,
                                     IRQF_TRIGGER_RISING | IRQF_ONESHOT,
                                     "tsc2005", ts);
        if (error) {
                dev_err(&spi->dev, "Failed to request irq, err: %d\n", error);
                goto err_free_mem;
        }

        spi_set_drvdata(spi, ts);
        error = sysfs_create_group(&spi->dev.kobj, &tsc2005_attr_group);
        if (error) {
                dev_err(&spi->dev,
                        "Failed to create sysfs attributes, err: %d\n", error);
                goto err_clear_drvdata;
        }

        error = input_register_device(ts->idev);
        if (error) {
                dev_err(&spi->dev,
                        "Failed to register input device, err: %d\n", error);
                goto err_remove_sysfs;
        }

        irq_set_irq_wake(spi->irq, 1);
        return 0;

err_remove_sysfs:
        sysfs_remove_group(&spi->dev.kobj, &tsc2005_attr_group);
err_clear_drvdata:
        spi_set_drvdata(spi, NULL);
        free_irq(spi->irq, ts);
err_free_mem:
        input_free_device(input_dev);
        kfree(ts);
        return error;
}

static int tsc2005_remove(struct spi_device *spi)
{
        struct tsc2005 *ts = spi_get_drvdata(spi);

        sysfs_remove_group(&ts->spi->dev.kobj, &tsc2005_attr_group);

        free_irq(ts->spi->irq, ts);
        input_unregister_device(ts->idev);
        kfree(ts);

        spi_set_drvdata(spi, NULL);
        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int tsc2005_suspend(struct device *dev)
{
        struct spi_device *spi = to_spi_device(dev);
        struct tsc2005 *ts = spi_get_drvdata(spi);

        mutex_lock(&ts->mutex);

        if (!ts->suspended && ts->opened)
                __tsc2005_disable(ts);

        ts->suspended = true;

        mutex_unlock(&ts->mutex);

        return 0;
}

static int tsc2005_resume(struct device *dev)
{
        struct spi_device *spi = to_spi_device(dev);
        struct tsc2005 *ts = spi_get_drvdata(spi);

        mutex_lock(&ts->mutex);

        if (ts->suspended && ts->opened)
                __tsc2005_enable(ts);

        ts->suspended = false;

        mutex_unlock(&ts->mutex);

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(tsc2005_pm_ops, tsc2005_suspend, tsc2005_resume);

static struct spi_driver tsc2005_driver = {
        .driver = {
                .name   = "tsc2005",
                .owner  = THIS_MODULE,
                .pm     = &tsc2005_pm_ops,
        },
        .probe  = tsc2005_probe,
        .remove = tsc2005_remove,
};

module_spi_driver(tsc2005_driver);

MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>");
MODULE_DESCRIPTION("TSC2005 Touchscreen Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:tsc2005");