atmel_mxt_ts.c

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/*
 * Atmel maXTouch Touchscreen driver
 *
 * Copyright (C) 2010 Samsung Electronics Co.Ltd
 * Author: Joonyoung Shim <[email protected]>
 *
 * 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.
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/firmware.h>
#include <linux/i2c.h>
#include <linux/i2c/atmel_mxt_ts.h>
#include <linux/input/mt.h>
#include <linux/interrupt.h>
#include <linux/slab.h>

/* Version */
#define MXT_VER_20      20
#define MXT_VER_21      21
#define MXT_VER_22      22

/* Slave addresses */
#define MXT_APP_LOW     0x4a
#define MXT_APP_HIGH        0x4b
#define MXT_BOOT_LOW        0x24
#define MXT_BOOT_HIGH       0x25

/* Firmware */
#define MXT_FW_NAME     "maxtouch.fw"

/* Registers */
#define MXT_INFO        0x00
#define MXT_FAMILY_ID       0x00
#define MXT_VARIANT_ID      0x01
#define MXT_VERSION     0x02
#define MXT_BUILD       0x03
#define MXT_MATRIX_X_SIZE   0x04
#define MXT_MATRIX_Y_SIZE   0x05
#define MXT_OBJECT_NUM      0x06
#define MXT_OBJECT_START    0x07

#define MXT_OBJECT_SIZE     6

/* Object types */
#define MXT_DEBUG_DIAGNOSTIC_T37    37
#define MXT_GEN_MESSAGE_T5      5
#define MXT_GEN_COMMAND_T6      6
#define MXT_GEN_POWER_T7        7
#define MXT_GEN_ACQUIRE_T8      8
#define MXT_GEN_DATASOURCE_T53      53
#define MXT_TOUCH_MULTI_T9      9
#define MXT_TOUCH_KEYARRAY_T15      15
#define MXT_TOUCH_PROXIMITY_T23     23
#define MXT_TOUCH_PROXKEY_T52       52
#define MXT_PROCI_GRIPFACE_T20      20
#define MXT_PROCG_NOISE_T22     22
#define MXT_PROCI_ONETOUCH_T24      24
#define MXT_PROCI_TWOTOUCH_T27      27
#define MXT_PROCI_GRIP_T40      40
#define MXT_PROCI_PALM_T41      41
#define MXT_PROCI_TOUCHSUPPRESSION_T42  42
#define MXT_PROCI_STYLUS_T47        47
#define MXT_PROCG_NOISESUPPRESSION_T48  48
#define MXT_SPT_COMMSCONFIG_T18     18
#define MXT_SPT_GPIOPWM_T19     19
#define MXT_SPT_SELFTEST_T25        25
#define MXT_SPT_CTECONFIG_T28       28
#define MXT_SPT_USERDATA_T38        38
#define MXT_SPT_DIGITIZER_T43       43
#define MXT_SPT_MESSAGECOUNT_T44    44
#define MXT_SPT_CTECONFIG_T46       46

/* MXT_GEN_COMMAND_T6 field */
#define MXT_COMMAND_RESET   0
#define MXT_COMMAND_BACKUPNV    1
#define MXT_COMMAND_CALIBRATE   2
#define MXT_COMMAND_REPORTALL   3
#define MXT_COMMAND_DIAGNOSTIC  5

/* MXT_GEN_POWER_T7 field */
#define MXT_POWER_IDLEACQINT    0
#define MXT_POWER_ACTVACQINT    1
#define MXT_POWER_ACTV2IDLETO   2

/* MXT_GEN_ACQUIRE_T8 field */
#define MXT_ACQUIRE_CHRGTIME    0
#define MXT_ACQUIRE_TCHDRIFT    2
#define MXT_ACQUIRE_DRIFTST 3
#define MXT_ACQUIRE_TCHAUTOCAL  4
#define MXT_ACQUIRE_SYNC    5
#define MXT_ACQUIRE_ATCHCALST   6
#define MXT_ACQUIRE_ATCHCALSTHR 7

/* MXT_TOUCH_MULTI_T9 field */
#define MXT_TOUCH_CTRL      0
#define MXT_TOUCH_XORIGIN   1
#define MXT_TOUCH_YORIGIN   2
#define MXT_TOUCH_XSIZE     3
#define MXT_TOUCH_YSIZE     4
#define MXT_TOUCH_BLEN      6
#define MXT_TOUCH_TCHTHR    7
#define MXT_TOUCH_TCHDI     8
#define MXT_TOUCH_ORIENT    9
#define MXT_TOUCH_MOVHYSTI  11
#define MXT_TOUCH_MOVHYSTN  12
#define MXT_TOUCH_NUMTOUCH  14
#define MXT_TOUCH_MRGHYST   15
#define MXT_TOUCH_MRGTHR    16
#define MXT_TOUCH_AMPHYST   17
#define MXT_TOUCH_XRANGE_LSB    18
#define MXT_TOUCH_XRANGE_MSB    19
#define MXT_TOUCH_YRANGE_LSB    20
#define MXT_TOUCH_YRANGE_MSB    21
#define MXT_TOUCH_XLOCLIP   22
#define MXT_TOUCH_XHICLIP   23
#define MXT_TOUCH_YLOCLIP   24
#define MXT_TOUCH_YHICLIP   25
#define MXT_TOUCH_XEDGECTRL 26
#define MXT_TOUCH_XEDGEDIST 27
#define MXT_TOUCH_YEDGECTRL 28
#define MXT_TOUCH_YEDGEDIST 29
#define MXT_TOUCH_JUMPLIMIT 30

/* MXT_PROCI_GRIPFACE_T20 field */
#define MXT_GRIPFACE_CTRL   0
#define MXT_GRIPFACE_XLOGRIP    1
#define MXT_GRIPFACE_XHIGRIP    2
#define MXT_GRIPFACE_YLOGRIP    3
#define MXT_GRIPFACE_YHIGRIP    4
#define MXT_GRIPFACE_MAXTCHS    5
#define MXT_GRIPFACE_SZTHR1 7
#define MXT_GRIPFACE_SZTHR2 8
#define MXT_GRIPFACE_SHPTHR1    9
#define MXT_GRIPFACE_SHPTHR2    10
#define MXT_GRIPFACE_SUPEXTTO   11

/* MXT_PROCI_NOISE field */
#define MXT_NOISE_CTRL      0
#define MXT_NOISE_OUTFLEN   1
#define MXT_NOISE_GCAFUL_LSB    3
#define MXT_NOISE_GCAFUL_MSB    4
#define MXT_NOISE_GCAFLL_LSB    5
#define MXT_NOISE_GCAFLL_MSB    6
#define MXT_NOISE_ACTVGCAFVALID 7
#define MXT_NOISE_NOISETHR  8
#define MXT_NOISE_FREQHOPSCALE  10
#define MXT_NOISE_FREQ0     11
#define MXT_NOISE_FREQ1     12
#define MXT_NOISE_FREQ2     13
#define MXT_NOISE_FREQ3     14
#define MXT_NOISE_FREQ4     15
#define MXT_NOISE_IDLEGCAFVALID 16

/* MXT_SPT_COMMSCONFIG_T18 */
#define MXT_COMMS_CTRL      0
#define MXT_COMMS_CMD       1

/* MXT_SPT_CTECONFIG_T28 field */
#define MXT_CTE_CTRL        0
#define MXT_CTE_CMD     1
#define MXT_CTE_MODE        2
#define MXT_CTE_IDLEGCAFDEPTH   3
#define MXT_CTE_ACTVGCAFDEPTH   4
#define MXT_CTE_VOLTAGE     5

#define MXT_VOLTAGE_DEFAULT 2700000
#define MXT_VOLTAGE_STEP    10000

/* Define for MXT_GEN_COMMAND_T6 */
#define MXT_BOOT_VALUE      0xa5
#define MXT_BACKUP_VALUE    0x55
#define MXT_BACKUP_TIME     25  /* msec */
#define MXT_RESET_TIME      65  /* msec */

#define MXT_FWRESET_TIME    175 /* msec */

/* Command to unlock bootloader */
#define MXT_UNLOCK_CMD_MSB  0xaa
#define MXT_UNLOCK_CMD_LSB  0xdc

/* Bootloader mode status */
#define MXT_WAITING_BOOTLOAD_CMD    0xc0    /* valid 7 6 bit only */
#define MXT_WAITING_FRAME_DATA  0x80    /* valid 7 6 bit only */
#define MXT_FRAME_CRC_CHECK 0x02
#define MXT_FRAME_CRC_FAIL  0x03
#define MXT_FRAME_CRC_PASS  0x04
#define MXT_APP_CRC_FAIL    0x40    /* valid 7 8 bit only */
#define MXT_BOOT_STATUS_MASK    0x3f

/* Touch status */
#define MXT_UNGRIP      (1 << 0)
#define MXT_SUPPRESS        (1 << 1)
#define MXT_AMP         (1 << 2)
#define MXT_VECTOR      (1 << 3)
#define MXT_MOVE        (1 << 4)
#define MXT_RELEASE     (1 << 5)
#define MXT_PRESS       (1 << 6)
#define MXT_DETECT      (1 << 7)

/* Touch orient bits */
#define MXT_XY_SWITCH       (1 << 0)
#define MXT_X_INVERT        (1 << 1)
#define MXT_Y_INVERT        (1 << 2)

/* Touchscreen absolute values */
#define MXT_MAX_AREA        0xff

struct mxt_info {
    u8 family_id;
    u8 variant_id;
    u8 version;
    u8 build;
    u8 matrix_xsize;
    u8 matrix_ysize;
    u8 object_num;
};

struct mxt_object {
    u8 type;
    u16 start_address;
    u8 size;        /* Size of each instance - 1 */
    u8 instances;       /* Number of instances - 1 */
    u8 num_report_ids;
} __packed;

struct mxt_message {
    u8 reportid;
    u8 message[7];
};

/* Each client has this additional data */
struct mxt_data {
    struct i2c_client *client;
    struct input_dev *input_dev;
    char phys[64];      /* device physical location */
    const struct mxt_platform_data *pdata;
    struct mxt_object *object_table;
    struct mxt_info info;
    unsigned int irq;
    unsigned int max_x;
    unsigned int max_y;

    /* Cached parameters from object table */
    u8 T6_reportid;
    u8 T9_reportid_min;
    u8 T9_reportid_max;
};

static bool mxt_object_readable(unsigned int type)
{
    switch (type) {
    case MXT_GEN_COMMAND_T6:
    case MXT_GEN_POWER_T7:
    case MXT_GEN_ACQUIRE_T8:
    case MXT_GEN_DATASOURCE_T53:
    case MXT_TOUCH_MULTI_T9:
    case MXT_TOUCH_KEYARRAY_T15:
    case MXT_TOUCH_PROXIMITY_T23:
    case MXT_TOUCH_PROXKEY_T52:
    case MXT_PROCI_GRIPFACE_T20:
    case MXT_PROCG_NOISE_T22:
    case MXT_PROCI_ONETOUCH_T24:
    case MXT_PROCI_TWOTOUCH_T27:
    case MXT_PROCI_GRIP_T40:
    case MXT_PROCI_PALM_T41:
    case MXT_PROCI_TOUCHSUPPRESSION_T42:
    case MXT_PROCI_STYLUS_T47:
    case MXT_PROCG_NOISESUPPRESSION_T48:
    case MXT_SPT_COMMSCONFIG_T18:
    case MXT_SPT_GPIOPWM_T19:
    case MXT_SPT_SELFTEST_T25:
    case MXT_SPT_CTECONFIG_T28:
    case MXT_SPT_USERDATA_T38:
    case MXT_SPT_DIGITIZER_T43:
    case MXT_SPT_CTECONFIG_T46:
        return true;
    default:
        return false;
    }
}

static bool mxt_object_writable(unsigned int type)
{
    switch (type) {
    case MXT_GEN_COMMAND_T6:
    case MXT_GEN_POWER_T7:
    case MXT_GEN_ACQUIRE_T8:
    case MXT_TOUCH_MULTI_T9:
    case MXT_TOUCH_KEYARRAY_T15:
    case MXT_TOUCH_PROXIMITY_T23:
    case MXT_TOUCH_PROXKEY_T52:
    case MXT_PROCI_GRIPFACE_T20:
    case MXT_PROCG_NOISE_T22:
    case MXT_PROCI_ONETOUCH_T24:
    case MXT_PROCI_TWOTOUCH_T27:
    case MXT_PROCI_GRIP_T40:
    case MXT_PROCI_PALM_T41:
    case MXT_PROCI_TOUCHSUPPRESSION_T42:
    case MXT_PROCI_STYLUS_T47:
    case MXT_PROCG_NOISESUPPRESSION_T48:
    case MXT_SPT_COMMSCONFIG_T18:
    case MXT_SPT_GPIOPWM_T19:
    case MXT_SPT_SELFTEST_T25:
    case MXT_SPT_CTECONFIG_T28:
    case MXT_SPT_DIGITIZER_T43:
    case MXT_SPT_CTECONFIG_T46:
        return true;
    default:
        return false;
    }
}

static void mxt_dump_message(struct device *dev,
                 struct mxt_message *message)
{
    dev_dbg(dev, "reportid: %u\tmessage: %*ph\n",
        message->reportid, 7, message->message);
}

static int mxt_check_bootloader(struct i2c_client *client,
                     unsigned int state)
{
    u8 val;

recheck:
    if (i2c_master_recv(client, &val, 1) != 1) {
        dev_err(&client->dev, "%s: i2c recv failed\n", __func__);
        return -EIO;
    }

    switch (state) {
    case MXT_WAITING_BOOTLOAD_CMD:
    case MXT_WAITING_FRAME_DATA:
        val &= ~MXT_BOOT_STATUS_MASK;
        break;
    case MXT_FRAME_CRC_PASS:
        if (val == MXT_FRAME_CRC_CHECK)
            goto recheck;
        break;
    default:
        return -EINVAL;
    }

    if (val != state) {
        dev_err(&client->dev, "Unvalid bootloader mode state\n");
        return -EINVAL;
    }

    return 0;
}

static int mxt_unlock_bootloader(struct i2c_client *client)
{
    u8 buf[2];

    buf[0] = MXT_UNLOCK_CMD_LSB;
    buf[1] = MXT_UNLOCK_CMD_MSB;

    if (i2c_master_send(client, buf, 2) != 2) {
        dev_err(&client->dev, "%s: i2c send failed\n", __func__);
        return -EIO;
    }

    return 0;
}

static int mxt_fw_write(struct i2c_client *client,
                 const u8 *data, unsigned int frame_size)
{
    if (i2c_master_send(client, data, frame_size) != frame_size) {
        dev_err(&client->dev, "%s: i2c send failed\n", __func__);
        return -EIO;
    }

    return 0;
}

static int __mxt_read_reg(struct i2c_client *client,
                   u16 reg, u16 len, void *val)
{
    struct i2c_msg xfer[2];
    u8 buf[2];
    int ret;

    buf[0] = reg & 0xff;
    buf[1] = (reg >> 8) & 0xff;

    /* Write register */
    xfer[0].addr = client->addr;
    xfer[0].flags = 0;
    xfer[0].len = 2;
    xfer[0].buf = buf;

    /* Read data */
    xfer[1].addr = client->addr;
    xfer[1].flags = I2C_M_RD;
    xfer[1].len = len;
    xfer[1].buf = val;

    ret = i2c_transfer(client->adapter, xfer, 2);
    if (ret == 2) {
        ret = 0;
    } else {
        if (ret >= 0)
            ret = -EIO;
        dev_err(&client->dev, "%s: i2c transfer failed (%d)\n",
            __func__, ret);
    }

    return ret;
}

static int mxt_read_reg(struct i2c_client *client, u16 reg, u8 *val)
{
    return __mxt_read_reg(client, reg, 1, val);
}

static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len,
               const void *val)
{
    u8 *buf;
    size_t count;
    int ret;

    count = len + 2;
    buf = kmalloc(count, GFP_KERNEL);
    if (!buf)
        return -ENOMEM;

    buf[0] = reg & 0xff;
    buf[1] = (reg >> 8) & 0xff;
    memcpy(&buf[2], val, len);

    ret = i2c_master_send(client, buf, count);
    if (ret == count) {
        ret = 0;
    } else {
        if (ret >= 0)
            ret = -EIO;
        dev_err(&client->dev, "%s: i2c send failed (%d)\n",
            __func__, ret);
    }

    kfree(buf);
    return ret;
}

static int mxt_write_reg(struct i2c_client *client, u16 reg, u8 val)
{
    return __mxt_write_reg(client, reg, 1, &val);
}

static struct mxt_object *
mxt_get_object(struct mxt_data *data, u8 type)
{
    struct mxt_object *object;
    int i;

    for (i = 0; i < data->info.object_num; i++) {
        object = data->object_table + i;
        if (object->type == type)
            return object;
    }

    dev_err(&data->client->dev, "Invalid object type\n");
    return NULL;
}

static int mxt_read_message(struct mxt_data *data,
                 struct mxt_message *message)
{
    struct mxt_object *object;
    u16 reg;

    object = mxt_get_object(data, MXT_GEN_MESSAGE_T5);
    if (!object)
        return -EINVAL;

    reg = object->start_address;
    return __mxt_read_reg(data->client, reg,
            sizeof(struct mxt_message), message);
}

static int mxt_write_object(struct mxt_data *data,
                 u8 type, u8 offset, u8 val)
{
    struct mxt_object *object;
    u16 reg;

    object = mxt_get_object(data, type);
    if (!object || offset >= object->size + 1)
        return -EINVAL;

    reg = object->start_address;
    return mxt_write_reg(data->client, reg + offset, val);
}

static void mxt_input_touchevent(struct mxt_data *data,
                      struct mxt_message *message, int id)
{
    struct device *dev = &data->client->dev;
    u8 status = message->message[0];
    struct input_dev *input_dev = data->input_dev;
    int x;
    int y;
    int area;
    int pressure;

    x = (message->message[1] << 4) | ((message->message[3] >> 4) & 0xf);
    y = (message->message[2] << 4) | ((message->message[3] & 0xf));
    if (data->max_x < 1024)
        x = x >> 2;
    if (data->max_y < 1024)
        y = y >> 2;

    area = message->message[4];
    pressure = message->message[5];

    dev_dbg(dev,
        "[%u] %c%c%c%c%c%c%c%c x: %5u y: %5u area: %3u amp: %3u\n",
        id,
        (status & MXT_DETECT) ? 'D' : '.',
        (status & MXT_PRESS) ? 'P' : '.',
        (status & MXT_RELEASE) ? 'R' : '.',
        (status & MXT_MOVE) ? 'M' : '.',
        (status & MXT_VECTOR) ? 'V' : '.',
        (status & MXT_AMP) ? 'A' : '.',
        (status & MXT_SUPPRESS) ? 'S' : '.',
        (status & MXT_UNGRIP) ? 'U' : '.',
        x, y, area, pressure);

    input_mt_slot(input_dev, id);
    input_mt_report_slot_state(input_dev, MT_TOOL_FINGER,
                   status & MXT_DETECT);

    if (status & MXT_DETECT) {
        input_report_abs(input_dev, ABS_MT_POSITION_X, x);
        input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
        input_report_abs(input_dev, ABS_MT_PRESSURE, pressure);
        input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, area);
    }
}

static unsigned mxt_extract_T6_csum(const u8 *csum)
{
    return csum[0] | (csum[1] << 8) | (csum[2] << 16);
}

static bool mxt_is_T9_message(struct mxt_data *data, struct mxt_message *msg)
{
    u8 id = msg->reportid;
    return (id >= data->T9_reportid_min && id <= data->T9_reportid_max);
}

static irqreturn_t mxt_interrupt(int irq, void *dev_id)
{
    struct mxt_data *data = dev_id;
    struct mxt_message message;
    const u8 *payload = &message.message[0];
    struct device *dev = &data->client->dev;
    u8 reportid;
    bool update_input = false;

    do {
        if (mxt_read_message(data, &message)) {
            dev_err(dev, "Failed to read message\n");
            goto end;
        }

        reportid = message.reportid;

        if (reportid == data->T6_reportid) {
            u8 status = payload[0];
            unsigned csum = mxt_extract_T6_csum(&payload[1]);
            dev_dbg(dev, "Status: %02x Config Checksum: %06x\n",
                status, csum);
        } else if (mxt_is_T9_message(data, &message)) {
            int id = reportid - data->T9_reportid_min;
            mxt_input_touchevent(data, &message, id);
            update_input = true;
        } else {
            mxt_dump_message(dev, &message);
        }
    } while (reportid != 0xff);

    if (update_input) {
        input_mt_report_pointer_emulation(data->input_dev, false);
        input_sync(data->input_dev);
    }

end:
    return IRQ_HANDLED;
}

static int mxt_check_reg_init(struct mxt_data *data)
{
    const struct mxt_platform_data *pdata = data->pdata;
    struct mxt_object *object;
    struct device *dev = &data->client->dev;
    int index = 0;
    int i, size;
    int ret;

    if (!pdata->config) {
        dev_dbg(dev, "No cfg data defined, skipping reg init\n");
        return 0;
    }

    for (i = 0; i < data->info.object_num; i++) {
        object = data->object_table + i;

        if (!mxt_object_writable(object->type))
            continue;

        size = (object->size + 1) * (object->instances + 1);
        if (index + size > pdata->config_length) {
            dev_err(dev, "Not enough config data!\n");
            return -EINVAL;
        }

        ret = __mxt_write_reg(data->client, object->start_address,
                size, &pdata->config[index]);
        if (ret)
            return ret;
        index += size;
    }

    return 0;
}

static int mxt_make_highchg(struct mxt_data *data)
{
    struct device *dev = &data->client->dev;
    struct mxt_message message;
    int count = 10;
    int error;

    /* Read dummy message to make high CHG pin */
    do {
        error = mxt_read_message(data, &message);
        if (error)
            return error;
    } while (message.reportid != 0xff && --count);

    if (!count) {
        dev_err(dev, "CHG pin isn't cleared\n");
        return -EBUSY;
    }

    return 0;
}

static void mxt_handle_pdata(struct mxt_data *data)
{
    const struct mxt_platform_data *pdata = data->pdata;
    u8 voltage;

    /* Set touchscreen lines */
    mxt_write_object(data, MXT_TOUCH_MULTI_T9, MXT_TOUCH_XSIZE,
            pdata->x_line);
    mxt_write_object(data, MXT_TOUCH_MULTI_T9, MXT_TOUCH_YSIZE,
            pdata->y_line);

    /* Set touchscreen orient */
    mxt_write_object(data, MXT_TOUCH_MULTI_T9, MXT_TOUCH_ORIENT,
            pdata->orient);

    /* Set touchscreen burst length */
    mxt_write_object(data, MXT_TOUCH_MULTI_T9,
            MXT_TOUCH_BLEN, pdata->blen);

    /* Set touchscreen threshold */
    mxt_write_object(data, MXT_TOUCH_MULTI_T9,
            MXT_TOUCH_TCHTHR, pdata->threshold);

    /* Set touchscreen resolution */
    mxt_write_object(data, MXT_TOUCH_MULTI_T9,
            MXT_TOUCH_XRANGE_LSB, (pdata->x_size - 1) & 0xff);
    mxt_write_object(data, MXT_TOUCH_MULTI_T9,
            MXT_TOUCH_XRANGE_MSB, (pdata->x_size - 1) >> 8);
    mxt_write_object(data, MXT_TOUCH_MULTI_T9,
            MXT_TOUCH_YRANGE_LSB, (pdata->y_size - 1) & 0xff);
    mxt_write_object(data, MXT_TOUCH_MULTI_T9,
            MXT_TOUCH_YRANGE_MSB, (pdata->y_size - 1) >> 8);

    /* Set touchscreen voltage */
    if (pdata->voltage) {
        if (pdata->voltage < MXT_VOLTAGE_DEFAULT) {
            voltage = (MXT_VOLTAGE_DEFAULT - pdata->voltage) /
                MXT_VOLTAGE_STEP;
            voltage = 0xff - voltage + 1;
        } else
            voltage = (pdata->voltage - MXT_VOLTAGE_DEFAULT) /
                MXT_VOLTAGE_STEP;

        mxt_write_object(data, MXT_SPT_CTECONFIG_T28,
                MXT_CTE_VOLTAGE, voltage);
    }
}

static int mxt_get_info(struct mxt_data *data)
{
    struct i2c_client *client = data->client;
    struct mxt_info *info = &data->info;
    int error;

    /* Read 7-byte info block starting at address 0 */
    error = __mxt_read_reg(client, MXT_INFO, sizeof(*info), info);
    if (error)
        return error;

    return 0;
}

static int mxt_get_object_table(struct mxt_data *data)
{
    struct i2c_client *client = data->client;
    size_t table_size;
    int error;
    int i;
    u8 reportid;

    table_size = data->info.object_num * sizeof(struct mxt_object);
    error = __mxt_read_reg(client, MXT_OBJECT_START, table_size,
            data->object_table);
    if (error)
        return error;

    /* Valid Report IDs start counting from 1 */
    reportid = 1;
    for (i = 0; i < data->info.object_num; i++) {
        struct mxt_object *object = data->object_table + i;
        u8 min_id, max_id;

        le16_to_cpus(&object->start_address);

        if (object->num_report_ids) {
            min_id = reportid;
            reportid += object->num_report_ids *
                    (object->instances + 1);
            max_id = reportid - 1;
        } else {
            min_id = 0;
            max_id = 0;
        }

        dev_dbg(&data->client->dev,
            "Type %2d Start %3d Size %3d Instances %2d ReportIDs %3u : %3u\n",
            object->type, object->start_address, object->size + 1,
            object->instances + 1, min_id, max_id);

        switch (object->type) {
        case MXT_GEN_COMMAND_T6:
            data->T6_reportid = min_id;
            break;
        case MXT_TOUCH_MULTI_T9:
            data->T9_reportid_min = min_id;
            data->T9_reportid_max = max_id;
            break;
        }
    }

    return 0;
}

static void mxt_free_object_table(struct mxt_data *data)
{
    kfree(data->object_table);
    data->object_table = NULL;
    data->T6_reportid = 0;
    data->T9_reportid_min = 0;
    data->T9_reportid_max = 0;

}

static int mxt_initialize(struct mxt_data *data)
{
    struct i2c_client *client = data->client;
    struct mxt_info *info = &data->info;
    int error;
    u8 val;

    error = mxt_get_info(data);
    if (error)
        return error;

    data->object_table = kcalloc(info->object_num,
                     sizeof(struct mxt_object),
                     GFP_KERNEL);
    if (!data->object_table) {
        dev_err(&client->dev, "Failed to allocate memory\n");
        return -ENOMEM;
    }

    /* Get object table information */
    error = mxt_get_object_table(data);
    if (error)
        goto err_free_object_table;

    /* Check register init values */
    error = mxt_check_reg_init(data);
    if (error)
        goto err_free_object_table;

    mxt_handle_pdata(data);

    /* Backup to memory */
    mxt_write_object(data, MXT_GEN_COMMAND_T6,
            MXT_COMMAND_BACKUPNV,
            MXT_BACKUP_VALUE);
    msleep(MXT_BACKUP_TIME);

    /* Soft reset */
    mxt_write_object(data, MXT_GEN_COMMAND_T6,
            MXT_COMMAND_RESET, 1);
    msleep(MXT_RESET_TIME);

    /* Update matrix size at info struct */
    error = mxt_read_reg(client, MXT_MATRIX_X_SIZE, &val);
    if (error)
        goto err_free_object_table;
    info->matrix_xsize = val;

    error = mxt_read_reg(client, MXT_MATRIX_Y_SIZE, &val);
    if (error)
        goto err_free_object_table;
    info->matrix_ysize = val;

    dev_info(&client->dev,
            "Family ID: %u Variant ID: %u Major.Minor.Build: %u.%u.%02X\n",
            info->family_id, info->variant_id, info->version >> 4,
            info->version & 0xf, info->build);

    dev_info(&client->dev,
            "Matrix X Size: %u Matrix Y Size: %u Object Num: %u\n",
            info->matrix_xsize, info->matrix_ysize,
            info->object_num);

    return 0;

err_free_object_table:
    mxt_free_object_table(data);
    return error;
}

static void mxt_calc_resolution(struct mxt_data *data)
{
    unsigned int max_x = data->pdata->x_size - 1;
    unsigned int max_y = data->pdata->y_size - 1;

    if (data->pdata->orient & MXT_XY_SWITCH) {
        data->max_x = max_y;
        data->max_y = max_x;
    } else {
        data->max_x = max_x;
        data->max_y = max_y;
    }
}

/* Firmware Version is returned as Major.Minor.Build */
static ssize_t mxt_fw_version_show(struct device *dev,
                   struct device_attribute *attr, char *buf)
{
    struct mxt_data *data = dev_get_drvdata(dev);
    struct mxt_info *info = &data->info;
    return scnprintf(buf, PAGE_SIZE, "%u.%u.%02X\n",
             info->version >> 4, info->version & 0xf, info->build);
}

/* Hardware Version is returned as FamilyID.VariantID */
static ssize_t mxt_hw_version_show(struct device *dev,
                   struct device_attribute *attr, char *buf)
{
    struct mxt_data *data = dev_get_drvdata(dev);
    struct mxt_info *info = &data->info;
    return scnprintf(buf, PAGE_SIZE, "%u.%u\n",
             info->family_id, info->variant_id);
}

static ssize_t mxt_show_instance(char *buf, int count,
                 struct mxt_object *object, int instance,
                 const u8 *val)
{
    int i;

    if (object->instances > 0)
        count += scnprintf(buf + count, PAGE_SIZE - count,
                   "Instance %u\n", instance);

    for (i = 0; i < object->size + 1; i++)
        count += scnprintf(buf + count, PAGE_SIZE - count,
                "\t[%2u]: %02x (%d)\n", i, val[i], val[i]);
    count += scnprintf(buf + count, PAGE_SIZE - count, "\n");

    return count;
}

static ssize_t mxt_object_show(struct device *dev,
                    struct device_attribute *attr, char *buf)
{
    struct mxt_data *data = dev_get_drvdata(dev);
    struct mxt_object *object;
    int count = 0;
    int i, j;
    int error;
    u8 *obuf;

    /* Pre-allocate buffer large enough to hold max sized object. */
    obuf = kmalloc(256, GFP_KERNEL);
    if (!obuf)
        return -ENOMEM;

    error = 0;
    for (i = 0; i < data->info.object_num; i++) {
        object = data->object_table + i;

        if (!mxt_object_readable(object->type))
            continue;

        count += scnprintf(buf + count, PAGE_SIZE - count,
                "T%u:\n", object->type);

        for (j = 0; j < object->instances + 1; j++) {
            u16 size = object->size + 1;
            u16 addr = object->start_address + j * size;

            error = __mxt_read_reg(data->client, addr, size, obuf);
            if (error)
                goto done;

            count = mxt_show_instance(buf, count, object, j, obuf);
        }
    }

done:
    kfree(obuf);
    return error ?: count;
}

static int mxt_load_fw(struct device *dev, const char *fn)
{
    struct mxt_data *data = dev_get_drvdata(dev);
    struct i2c_client *client = data->client;
    const struct firmware *fw = NULL;
    unsigned int frame_size;
    unsigned int pos = 0;
    int ret;

    ret = request_firmware(&fw, fn, dev);
    if (ret) {
        dev_err(dev, "Unable to open firmware %s\n", fn);
        return ret;
    }

    /* Change to the bootloader mode */
    mxt_write_object(data, MXT_GEN_COMMAND_T6,
            MXT_COMMAND_RESET, MXT_BOOT_VALUE);
    msleep(MXT_RESET_TIME);

    /* Change to slave address of bootloader */
    if (client->addr == MXT_APP_LOW)
        client->addr = MXT_BOOT_LOW;
    else
        client->addr = MXT_BOOT_HIGH;

    ret = mxt_check_bootloader(client, MXT_WAITING_BOOTLOAD_CMD);
    if (ret)
        goto out;

    /* Unlock bootloader */
    mxt_unlock_bootloader(client);

    while (pos < fw->size) {
        ret = mxt_check_bootloader(client,
                        MXT_WAITING_FRAME_DATA);
        if (ret)
            goto out;

        frame_size = ((*(fw->data + pos) << 8) | *(fw->data + pos + 1));

        /* We should add 2 at frame size as the the firmware data is not
         * included the CRC bytes.
         */
        frame_size += 2;

        /* Write one frame to device */
        mxt_fw_write(client, fw->data + pos, frame_size);

        ret = mxt_check_bootloader(client,
                        MXT_FRAME_CRC_PASS);
        if (ret)
            goto out;

        pos += frame_size;

        dev_dbg(dev, "Updated %d bytes / %zd bytes\n", pos, fw->size);
    }

out:
    release_firmware(fw);

    /* Change to slave address of application */
    if (client->addr == MXT_BOOT_LOW)
        client->addr = MXT_APP_LOW;
    else
        client->addr = MXT_APP_HIGH;

    return ret;
}

static ssize_t mxt_update_fw_store(struct device *dev,
                    struct device_attribute *attr,
                    const char *buf, size_t count)
{
    struct mxt_data *data = dev_get_drvdata(dev);
    int error;

    disable_irq(data->irq);

    error = mxt_load_fw(dev, MXT_FW_NAME);
    if (error) {
        dev_err(dev, "The firmware update failed(%d)\n", error);
        count = error;
    } else {
        dev_dbg(dev, "The firmware update succeeded\n");

        /* Wait for reset */
        msleep(MXT_FWRESET_TIME);

        mxt_free_object_table(data);

        mxt_initialize(data);
    }

    enable_irq(data->irq);

    error = mxt_make_highchg(data);
    if (error)
        return error;

    return count;
}

static DEVICE_ATTR(fw_version, S_IRUGO, mxt_fw_version_show, NULL);
static DEVICE_ATTR(hw_version, S_IRUGO, mxt_hw_version_show, NULL);
static DEVICE_ATTR(object, S_IRUGO, mxt_object_show, NULL);
static DEVICE_ATTR(update_fw, S_IWUSR, NULL, mxt_update_fw_store);

static struct attribute *mxt_attrs[] = {
    &dev_attr_fw_version.attr,
    &dev_attr_hw_version.attr,
    &dev_attr_object.attr,
    &dev_attr_update_fw.attr,
    NULL
};

static const struct attribute_group mxt_attr_group = {
    .attrs = mxt_attrs,
};

static void mxt_start(struct mxt_data *data)
{
    /* Touch enable */
    mxt_write_object(data,
            MXT_TOUCH_MULTI_T9, MXT_TOUCH_CTRL, 0x83);
}

static void mxt_stop(struct mxt_data *data)
{
    /* Touch disable */
    mxt_write_object(data,
            MXT_TOUCH_MULTI_T9, MXT_TOUCH_CTRL, 0);
}

static int mxt_input_open(struct input_dev *dev)
{
    struct mxt_data *data = input_get_drvdata(dev);

    mxt_start(data);

    return 0;
}

static void mxt_input_close(struct input_dev *dev)
{
    struct mxt_data *data = input_get_drvdata(dev);

    mxt_stop(data);
}

static int __devinit mxt_probe(struct i2c_client *client,
        const struct i2c_device_id *id)
{
    const struct mxt_platform_data *pdata = client->dev.platform_data;
    struct mxt_data *data;
    struct input_dev *input_dev;
    int error;
    unsigned int num_mt_slots;

    if (!pdata)
        return -EINVAL;

    data = kzalloc(sizeof(struct mxt_data), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!data || !input_dev) {
        dev_err(&client->dev, "Failed to allocate memory\n");
        error = -ENOMEM;
        goto err_free_mem;
    }

    input_dev->name = "Atmel maXTouch Touchscreen";
    snprintf(data->phys, sizeof(data->phys), "i2c-%u-%04x/input0",
         client->adapter->nr, client->addr);
    input_dev->phys = data->phys;

    input_dev->id.bustype = BUS_I2C;
    input_dev->dev.parent = &client->dev;
    input_dev->open = mxt_input_open;
    input_dev->close = mxt_input_close;

    data->client = client;
    data->input_dev = input_dev;
    data->pdata = pdata;
    data->irq = client->irq;

    mxt_calc_resolution(data);

    error = mxt_initialize(data);
    if (error)
        goto err_free_mem;

    __set_bit(EV_ABS, input_dev->evbit);
    __set_bit(EV_KEY, input_dev->evbit);
    __set_bit(BTN_TOUCH, input_dev->keybit);

    /* For single touch */
    input_set_abs_params(input_dev, ABS_X,
                 0, data->max_x, 0, 0);
    input_set_abs_params(input_dev, ABS_Y,
                 0, data->max_y, 0, 0);
    input_set_abs_params(input_dev, ABS_PRESSURE,
                 0, 255, 0, 0);

    /* For multi touch */
    num_mt_slots = data->T9_reportid_max - data->T9_reportid_min + 1;
    error = input_mt_init_slots(input_dev, num_mt_slots, 0);
    if (error)
        goto err_free_object;
    input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
                 0, MXT_MAX_AREA, 0, 0);
    input_set_abs_params(input_dev, ABS_MT_POSITION_X,
                 0, data->max_x, 0, 0);
    input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
                 0, data->max_y, 0, 0);
    input_set_abs_params(input_dev, ABS_MT_PRESSURE,
                 0, 255, 0, 0);

    input_set_drvdata(input_dev, data);
    i2c_set_clientdata(client, data);

    error = request_threaded_irq(client->irq, NULL, mxt_interrupt,
                     pdata->irqflags | IRQF_ONESHOT,
                     client->name, data);
    if (error) {
        dev_err(&client->dev, "Failed to register interrupt\n");
        goto err_free_object;
    }

    error = mxt_make_highchg(data);
    if (error)
        goto err_free_irq;

    error = input_register_device(input_dev);
    if (error)
        goto err_free_irq;

    error = sysfs_create_group(&client->dev.kobj, &mxt_attr_group);
    if (error)
        goto err_unregister_device;

    return 0;

err_unregister_device:
    input_unregister_device(input_dev);
    input_dev = NULL;
err_free_irq:
    free_irq(client->irq, data);
err_free_object:
    kfree(data->object_table);
err_free_mem:
    input_free_device(input_dev);
    kfree(data);
    return error;
}

static int __devexit mxt_remove(struct i2c_client *client)
{
    struct mxt_data *data = i2c_get_clientdata(client);

    sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
    free_irq(data->irq, data);
    input_unregister_device(data->input_dev);
    kfree(data->object_table);
    kfree(data);

    return 0;
}

#ifdef CONFIG_PM_SLEEP
static int mxt_suspend(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct mxt_data *data = i2c_get_clientdata(client);
    struct input_dev *input_dev = data->input_dev;

    mutex_lock(&input_dev->mutex);

    if (input_dev->users)
        mxt_stop(data);

    mutex_unlock(&input_dev->mutex);

    return 0;
}

static int mxt_resume(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct mxt_data *data = i2c_get_clientdata(client);
    struct input_dev *input_dev = data->input_dev;

    /* Soft reset */
    mxt_write_object(data, MXT_GEN_COMMAND_T6,
            MXT_COMMAND_RESET, 1);

    msleep(MXT_RESET_TIME);

    mutex_lock(&input_dev->mutex);

    if (input_dev->users)
        mxt_start(data);

    mutex_unlock(&input_dev->mutex);

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(mxt_pm_ops, mxt_suspend, mxt_resume);

static const struct i2c_device_id mxt_id[] = {
    { "qt602240_ts", 0 },
    { "atmel_mxt_ts", 0 },
    { "mXT224", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, mxt_id);

static struct i2c_driver mxt_driver = {
    .driver = {
        .name   = "atmel_mxt_ts",
        .owner  = THIS_MODULE,
        .pm = &mxt_pm_ops,
    },
    .probe      = mxt_probe,
    .remove     = __devexit_p(mxt_remove),
    .id_table   = mxt_id,
};

module_i2c_driver(mxt_driver);

/* Module information */
MODULE_AUTHOR("Joonyoung Shim <[email protected]>");
MODULE_DESCRIPTION("Atmel maXTouch Touchscreen driver");
MODULE_LICENSE("GPL");