// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  HID driver for multitouch panels
 *
 *  Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>
 *  Copyright (c) 2010-2013 Benjamin Tissoires <benjamin.tissoires@gmail.com>
 *  Copyright (c) 2010-2012 Ecole Nationale de l'Aviation Civile, France
 *  Copyright (c) 2012-2013 Red Hat, Inc
 *
 *  This code is partly based on hid-egalax.c:
 *
 *  Copyright (c) 2010 Stephane Chatty <chatty@enac.fr>
 *  Copyright (c) 2010 Henrik Rydberg <rydberg@euromail.se>
 *  Copyright (c) 2010 Canonical, Ltd.
 *
 *  This code is partly based on hid-3m-pct.c:
 *
 *  Copyright (c) 2009-2010 Stephane Chatty <chatty@enac.fr>
 *  Copyright (c) 2010      Henrik Rydberg <rydberg@euromail.se>
 *  Copyright (c) 2010      Canonical, Ltd.
 */

/*
 */

/*
 * This driver is regularly tested thanks to the test suite in hid-tools[1].
 * Please run these regression tests before patching this module so that
 * your patch won't break existing known devices.
 *
 * [1] https://gitlab.freedesktop.org/libevdev/hid-tools
 */

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input/mt.h>
#include <linux/jiffies.h>
#include <linux/string.h>
#include <linux/timer.h>


MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
MODULE_DESCRIPTION("HID multitouch panels");
MODULE_LICENSE("GPL");

#include "hid-ids.h"

/* quirks to control the device */
#define MT_QUIRK_NOT_SEEN_MEANS_UP      BIT(0)
#define MT_QUIRK_SLOT_IS_CONTACTID      BIT(1)
#define MT_QUIRK_CYPRESS                BIT(2)
#define MT_QUIRK_SLOT_IS_CONTACTNUMBER  BIT(3)
#define MT_QUIRK_ALWAYS_VALID           BIT(4)
#define MT_QUIRK_VALID_IS_INRANGE       BIT(5)
#define MT_QUIRK_VALID_IS_CONFIDENCE    BIT(6)
#define MT_QUIRK_CONFIDENCE             BIT(7)
#define MT_QUIRK_SLOT_IS_CONTACTID_MINUS_ONE    BIT(8)
#define MT_QUIRK_NO_AREA                BIT(9)
#define MT_QUIRK_IGNORE_DUPLICATES      BIT(10)
#define MT_QUIRK_HOVERING               BIT(11)
#define MT_QUIRK_CONTACT_CNT_ACCURATE   BIT(12)
#define MT_QUIRK_FORCE_GET_FEATURE      BIT(13)
#define MT_QUIRK_FIX_CONST_CONTACT_ID   BIT(14)
#define MT_QUIRK_TOUCH_SIZE_SCALING     BIT(15)
#define MT_QUIRK_STICKY_FINGERS         BIT(16)
#define MT_QUIRK_ASUS_CUSTOM_UP         BIT(17)
#define MT_QUIRK_WIN8_PTP_BUTTONS       BIT(18)
#define MT_QUIRK_SEPARATE_APP_REPORT    BIT(19)
#define MT_QUIRK_FORCE_MULTI_INPUT      BIT(20)

#define MT_INPUTMODE_TOUCHSCREEN        0x02
#define MT_INPUTMODE_TOUCHPAD           0x03

#define MT_BUTTONTYPE_CLICKPAD          0

enum latency_mode {
        HID_LATENCY_NORMAL = 0,
        HID_LATENCY_HIGH = 1,
};

#define MT_IO_FLAGS_RUNNING             0
#define MT_IO_FLAGS_ACTIVE_SLOTS        1
#define MT_IO_FLAGS_PENDING_SLOTS       2

static const bool mtrue = true;         /* default for true */
static const bool mfalse;               /* default for false */
static const __s32 mzero;               /* default for 0 */

#define DEFAULT_TRUE    ((void *)&mtrue)
#define DEFAULT_FALSE   ((void *)&mfalse)
#define DEFAULT_ZERO    ((void *)&mzero)

struct mt_usages {
        struct list_head list;
        __s32 *x, *y, *cx, *cy, *p, *w, *h, *a;
        __s32 *contactid;       /* the device ContactID assigned to this slot */
        bool *tip_state;        /* is the touch valid? */
        bool *inrange_state;    /* is the finger in proximity of the sensor? */
        bool *confidence_state; /* is the touch made by a finger? */
};

struct mt_application {
        struct list_head list;
        unsigned int application;
        unsigned int report_id;
        struct list_head mt_usages;     /* mt usages list */

        __s32 quirks;

        __s32 *scantime;                /* scantime reported */
        __s32 scantime_logical_max;     /* max value for raw scantime */

        __s32 *raw_cc;                  /* contact count in the report */
        int left_button_state;          /* left button state */
        unsigned int mt_flags;          /* flags to pass to input-mt */

        unsigned long *pending_palm_slots;      /* slots where we reported palm
                                                 * and need to release */

        __u8 num_received;      /* how many contacts we received */
        __u8 num_expected;      /* expected last contact index */
        __u8 buttons_count;     /* number of physical buttons per touchpad */
        __u8 touches_by_report; /* how many touches are present in one report:
                                 * 1 means we should use a serial protocol
                                 * > 1 means hybrid (multitouch) protocol
                                 */

        __s32 dev_time;         /* the scan time provided by the device */
        unsigned long jiffies;  /* the frame's jiffies */
        int timestamp;          /* the timestamp to be sent */
        int prev_scantime;              /* scantime reported previously */

        bool have_contact_count;
};

struct mt_class {
        __s32 name;     /* MT_CLS */
        __s32 quirks;
        __s32 sn_move;  /* Signal/noise ratio for move events */
        __s32 sn_width; /* Signal/noise ratio for width events */
        __s32 sn_height;        /* Signal/noise ratio for height events */
        __s32 sn_pressure;      /* Signal/noise ratio for pressure events */
        __u8 maxcontacts;
        bool is_indirect;       /* true for touchpads */
        bool export_all_inputs; /* do not ignore mouse, keyboards, etc... */
};

struct mt_report_data {
        struct list_head list;
        struct hid_report *report;
        struct mt_application *application;
        bool is_mt_collection;
};

struct mt_device {
        struct mt_class mtclass;        /* our mt device class */
        struct timer_list release_timer;        /* to release sticky fingers */
        struct hid_device *hdev;        /* hid_device we're attached to */
        unsigned long mt_io_flags;      /* mt flags (MT_IO_FLAGS_*) */
        __u8 inputmode_value;   /* InputMode HID feature value */
        __u8 maxcontacts;
        bool is_buttonpad;      /* is this device a button pad? */
        bool serial_maybe;      /* need to check for serial protocol */

        struct list_head applications;
        struct list_head reports;
};

static void mt_post_parse_default_settings(struct mt_device *td,
                                           struct mt_application *app);
static void mt_post_parse(struct mt_device *td, struct mt_application *app);

/* classes of device behavior */
#define MT_CLS_DEFAULT                          0x0001

#define MT_CLS_SERIAL                           0x0002
#define MT_CLS_CONFIDENCE                       0x0003
#define MT_CLS_CONFIDENCE_CONTACT_ID            0x0004
#define MT_CLS_CONFIDENCE_MINUS_ONE             0x0005
#define MT_CLS_DUAL_INRANGE_CONTACTID           0x0006
#define MT_CLS_DUAL_INRANGE_CONTACTNUMBER       0x0007
/* reserved                                     0x0008 */
#define MT_CLS_INRANGE_CONTACTNUMBER            0x0009
#define MT_CLS_NSMU                             0x000a
/* reserved                                     0x0010 */
/* reserved                                     0x0011 */
#define MT_CLS_WIN_8                            0x0012
#define MT_CLS_EXPORT_ALL_INPUTS                0x0013
/* reserved                                     0x0014 */
#define MT_CLS_WIN_8_FORCE_MULTI_INPUT          0x0015

/* vendor specific classes */
#define MT_CLS_3M                               0x0101
/* reserved                                     0x0102 */
#define MT_CLS_EGALAX                           0x0103
#define MT_CLS_EGALAX_SERIAL                    0x0104
#define MT_CLS_TOPSEED                          0x0105
#define MT_CLS_PANASONIC                        0x0106
#define MT_CLS_FLATFROG                         0x0107
#define MT_CLS_GENERALTOUCH_TWOFINGERS          0x0108
#define MT_CLS_GENERALTOUCH_PWT_TENFINGERS      0x0109
#define MT_CLS_LG                               0x010a
#define MT_CLS_ASUS                             0x010b
#define MT_CLS_VTL                              0x0110
#define MT_CLS_GOOGLE                           0x0111
#define MT_CLS_RAZER_BLADE_STEALTH              0x0112
#define MT_CLS_SMART_TECH                       0x0113

#define MT_DEFAULT_MAXCONTACT   10
#define MT_MAX_MAXCONTACT       250

/*
 * Resync device and local timestamps after that many microseconds without
 * receiving data.
 */
#define MAX_TIMESTAMP_INTERVAL  1000000

#define MT_USB_DEVICE(v, p)     HID_DEVICE(BUS_USB, HID_GROUP_MULTITOUCH, v, p)
#define MT_BT_DEVICE(v, p)      HID_DEVICE(BUS_BLUETOOTH, HID_GROUP_MULTITOUCH, v, p)

/*
 * these device-dependent functions determine what slot corresponds
 * to a valid contact that was just read.
 */

static int cypress_compute_slot(struct mt_application *application,
                                struct mt_usages *slot)
{
        if (*slot->contactid != 0 || application->num_received == 0)
                return *slot->contactid;
        else
                return -1;
}

static const struct mt_class mt_classes[] = {
        { .name = MT_CLS_DEFAULT,
                .quirks = MT_QUIRK_ALWAYS_VALID |
                        MT_QUIRK_CONTACT_CNT_ACCURATE },
        { .name = MT_CLS_NSMU,
                .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP },
        { .name = MT_CLS_SERIAL,
                .quirks = MT_QUIRK_ALWAYS_VALID},
        { .name = MT_CLS_CONFIDENCE,
                .quirks = MT_QUIRK_VALID_IS_CONFIDENCE },
        { .name = MT_CLS_CONFIDENCE_CONTACT_ID,
                .quirks = MT_QUIRK_VALID_IS_CONFIDENCE |
                        MT_QUIRK_SLOT_IS_CONTACTID },
        { .name = MT_CLS_CONFIDENCE_MINUS_ONE,
                .quirks = MT_QUIRK_VALID_IS_CONFIDENCE |
                        MT_QUIRK_SLOT_IS_CONTACTID_MINUS_ONE },
        { .name = MT_CLS_DUAL_INRANGE_CONTACTID,
                .quirks = MT_QUIRK_VALID_IS_INRANGE |
                        MT_QUIRK_SLOT_IS_CONTACTID,
                .maxcontacts = 2 },
        { .name = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
                .quirks = MT_QUIRK_VALID_IS_INRANGE |
                        MT_QUIRK_SLOT_IS_CONTACTNUMBER,
                .maxcontacts = 2 },
        { .name = MT_CLS_INRANGE_CONTACTNUMBER,
                .quirks = MT_QUIRK_VALID_IS_INRANGE |
                        MT_QUIRK_SLOT_IS_CONTACTNUMBER },
        { .name = MT_CLS_WIN_8,
                .quirks = MT_QUIRK_ALWAYS_VALID |
                        MT_QUIRK_IGNORE_DUPLICATES |
                        MT_QUIRK_HOVERING |
                        MT_QUIRK_CONTACT_CNT_ACCURATE |
                        MT_QUIRK_STICKY_FINGERS |
                        MT_QUIRK_WIN8_PTP_BUTTONS,
                .export_all_inputs = true },
        { .name = MT_CLS_EXPORT_ALL_INPUTS,
                .quirks = MT_QUIRK_ALWAYS_VALID |
                        MT_QUIRK_CONTACT_CNT_ACCURATE,
                .export_all_inputs = true },
        { .name = MT_CLS_WIN_8_FORCE_MULTI_INPUT,
                .quirks = MT_QUIRK_ALWAYS_VALID |
                        MT_QUIRK_IGNORE_DUPLICATES |
                        MT_QUIRK_HOVERING |
                        MT_QUIRK_CONTACT_CNT_ACCURATE |
                        MT_QUIRK_STICKY_FINGERS |
                        MT_QUIRK_WIN8_PTP_BUTTONS |
                        MT_QUIRK_FORCE_MULTI_INPUT,
                .export_all_inputs = true },

        /*
         * vendor specific classes
         */
        { .name = MT_CLS_3M,
                .quirks = MT_QUIRK_VALID_IS_CONFIDENCE |
                        MT_QUIRK_SLOT_IS_CONTACTID |
                        MT_QUIRK_TOUCH_SIZE_SCALING,
                .sn_move = 2048,
                .sn_width = 128,
                .sn_height = 128,
                .maxcontacts = 60,
        },
        { .name = MT_CLS_EGALAX,
                .quirks =  MT_QUIRK_SLOT_IS_CONTACTID |
                        MT_QUIRK_VALID_IS_INRANGE,
                .sn_move = 4096,
                .sn_pressure = 32,
        },
        { .name = MT_CLS_EGALAX_SERIAL,
                .quirks =  MT_QUIRK_SLOT_IS_CONTACTID |
                        MT_QUIRK_ALWAYS_VALID,
                .sn_move = 4096,
                .sn_pressure = 32,
        },
        { .name = MT_CLS_TOPSEED,
                .quirks = MT_QUIRK_ALWAYS_VALID,
                .is_indirect = true,
                .maxcontacts = 2,
        },
        { .name = MT_CLS_PANASONIC,
                .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP,
                .maxcontacts = 4 },
        { .name = MT_CLS_GENERALTOUCH_TWOFINGERS,
                .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP |
                        MT_QUIRK_VALID_IS_INRANGE |
                        MT_QUIRK_SLOT_IS_CONTACTID,
                .maxcontacts = 2
        },
        { .name = MT_CLS_GENERALTOUCH_PWT_TENFINGERS,
                .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP |
                        MT_QUIRK_SLOT_IS_CONTACTID
        },

        { .name = MT_CLS_FLATFROG,
                .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP |
                        MT_QUIRK_NO_AREA,
                .sn_move = 2048,
                .maxcontacts = 40,
        },
        { .name = MT_CLS_LG,
                .quirks = MT_QUIRK_ALWAYS_VALID |
                        MT_QUIRK_FIX_CONST_CONTACT_ID |
                        MT_QUIRK_IGNORE_DUPLICATES |
                        MT_QUIRK_HOVERING |
                        MT_QUIRK_CONTACT_CNT_ACCURATE },
        { .name = MT_CLS_ASUS,
                .quirks = MT_QUIRK_ALWAYS_VALID |
                        MT_QUIRK_CONTACT_CNT_ACCURATE |
                        MT_QUIRK_ASUS_CUSTOM_UP },
        { .name = MT_CLS_VTL,
                .quirks = MT_QUIRK_ALWAYS_VALID |
                        MT_QUIRK_CONTACT_CNT_ACCURATE |
                        MT_QUIRK_FORCE_GET_FEATURE,
        },
        { .name = MT_CLS_GOOGLE,
                .quirks = MT_QUIRK_ALWAYS_VALID |
                        MT_QUIRK_CONTACT_CNT_ACCURATE |
                        MT_QUIRK_SLOT_IS_CONTACTID |
                        MT_QUIRK_HOVERING
        },
        { .name = MT_CLS_RAZER_BLADE_STEALTH,
                .quirks = MT_QUIRK_ALWAYS_VALID |
                        MT_QUIRK_IGNORE_DUPLICATES |
                        MT_QUIRK_HOVERING |
                        MT_QUIRK_CONTACT_CNT_ACCURATE |
                        MT_QUIRK_WIN8_PTP_BUTTONS,
        },
        { .name = MT_CLS_SMART_TECH,
                .quirks = MT_QUIRK_ALWAYS_VALID |
                        MT_QUIRK_IGNORE_DUPLICATES |
                        MT_QUIRK_CONTACT_CNT_ACCURATE |
                        MT_QUIRK_SEPARATE_APP_REPORT,
        },
        { }
};

static ssize_t mt_show_quirks(struct device *dev,
                           struct device_attribute *attr,
                           char *buf)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct mt_device *td = hid_get_drvdata(hdev);

        return sprintf(buf, "%u\n", td->mtclass.quirks);
}

static ssize_t mt_set_quirks(struct device *dev,
                          struct device_attribute *attr,
                          const char *buf, size_t count)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct mt_device *td = hid_get_drvdata(hdev);
        struct mt_application *application;

        unsigned long val;

        if (kstrtoul(buf, 0, &val))
                return -EINVAL;

        td->mtclass.quirks = val;

        list_for_each_entry(application, &td->applications, list) {
                application->quirks = val;
                if (!application->have_contact_count)
                        application->quirks &= ~MT_QUIRK_CONTACT_CNT_ACCURATE;
        }

        return count;
}

static DEVICE_ATTR(quirks, S_IWUSR | S_IRUGO, mt_show_quirks, mt_set_quirks);

static struct attribute *sysfs_attrs[] = {
        &dev_attr_quirks.attr,
        NULL
};

static const struct attribute_group mt_attribute_group = {
        .attrs = sysfs_attrs
};

static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
{
        int ret;
        u32 size = hid_report_len(report);
        u8 *buf;

        /*
         * Do not fetch the feature report if the device has been explicitly
         * marked as non-capable.
         */
        if (hdev->quirks & HID_QUIRK_NO_INIT_REPORTS)
                return;

        buf = hid_alloc_report_buf(report, GFP_KERNEL);
        if (!buf)
                return;

        ret = hid_hw_raw_request(hdev, report->id, buf, size,
                                 HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
        if (ret < 0) {
                dev_warn(&hdev->dev, "failed to fetch feature %d\n",
                         report->id);
        } else {
                ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, buf,
                                           size, 0);
                if (ret)
                        dev_warn(&hdev->dev, "failed to report feature\n");
        }

        kfree(buf);
}

static void mt_feature_mapping(struct hid_device *hdev,
                struct hid_field *field, struct hid_usage *usage)
{
        struct mt_device *td = hid_get_drvdata(hdev);

        switch (usage->hid) {
        case HID_DG_CONTACTMAX:
                mt_get_feature(hdev, field->report);

                td->maxcontacts = field->value[0];
                if (!td->maxcontacts &&
                    field->logical_maximum <= MT_MAX_MAXCONTACT)
                        td->maxcontacts = field->logical_maximum;
                if (td->mtclass.maxcontacts)
                        /* check if the maxcontacts is given by the class */
                        td->maxcontacts = td->mtclass.maxcontacts;

                break;
        case HID_DG_BUTTONTYPE:
                if (usage->usage_index >= field->report_count) {
                        dev_err(&hdev->dev, "HID_DG_BUTTONTYPE out of range\n");
                        break;
                }

                mt_get_feature(hdev, field->report);
                if (field->value[usage->usage_index] == MT_BUTTONTYPE_CLICKPAD)
                        td->is_buttonpad = true;

                break;
        case 0xff0000c5:
                /* Retrieve the Win8 blob once to enable some devices */
                if (usage->usage_index == 0)
                        mt_get_feature(hdev, field->report);
                break;
        }
}

static void set_abs(struct input_dev *input, unsigned int code,
                struct hid_field *field, int snratio)
{
        int fmin = field->logical_minimum;
        int fmax = field->logical_maximum;
        int fuzz = snratio ? (fmax - fmin) / snratio : 0;
        input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
        input_abs_set_res(input, code, hidinput_calc_abs_res(field, code));
}

static struct mt_usages *mt_allocate_usage(struct hid_device *hdev,
                                           struct mt_application *application)
{
        struct mt_usages *usage;

        usage = devm_kzalloc(&hdev->dev, sizeof(*usage), GFP_KERNEL);
        if (!usage)
                return NULL;

        /* set some defaults so we do not need to check for null pointers */
        usage->x = DEFAULT_ZERO;
        usage->y = DEFAULT_ZERO;
        usage->cx = DEFAULT_ZERO;
        usage->cy = DEFAULT_ZERO;
        usage->p = DEFAULT_ZERO;
        usage->w = DEFAULT_ZERO;
        usage->h = DEFAULT_ZERO;
        usage->a = DEFAULT_ZERO;
        usage->contactid = DEFAULT_ZERO;
        usage->tip_state = DEFAULT_FALSE;
        usage->inrange_state = DEFAULT_FALSE;
        usage->confidence_state = DEFAULT_TRUE;

        list_add_tail(&usage->list, &application->mt_usages);

        return usage;
}

static struct mt_application *mt_allocate_application(struct mt_device *td,
                                                      struct hid_report *report)
{
        unsigned int application = report->application;
        struct mt_application *mt_application;

        mt_application = devm_kzalloc(&td->hdev->dev, sizeof(*mt_application),
                                      GFP_KERNEL);
        if (!mt_application)
                return NULL;

        mt_application->application = application;
        INIT_LIST_HEAD(&mt_application->mt_usages);

        if (application == HID_DG_TOUCHSCREEN)
                mt_application->mt_flags |= INPUT_MT_DIRECT;

        /*
         * Model touchscreens providing buttons as touchpads.
         */
        if (application == HID_DG_TOUCHPAD) {
                mt_application->mt_flags |= INPUT_MT_POINTER;
                td->inputmode_value = MT_INPUTMODE_TOUCHPAD;
        }

        mt_application->scantime = DEFAULT_ZERO;
        mt_application->raw_cc = DEFAULT_ZERO;
        mt_application->quirks = td->mtclass.quirks;
        mt_application->report_id = report->id;

        list_add_tail(&mt_application->list, &td->applications);

        return mt_application;
}

static struct mt_application *mt_find_application(struct mt_device *td,
                                                  struct hid_report *report)
{
        unsigned int application = report->application;
        struct mt_application *tmp, *mt_application = NULL;

        list_for_each_entry(tmp, &td->applications, list) {
                if (application == tmp->application) {
                        if (!(td->mtclass.quirks & MT_QUIRK_SEPARATE_APP_REPORT) ||
                            tmp->report_id == report->id) {
                                mt_application = tmp;
                                break;
                        }
                }
        }

        if (!mt_application)
                mt_application = mt_allocate_application(td, report);

        return mt_application;
}

static struct mt_report_data *mt_allocate_report_data(struct mt_device *td,
                                                      struct hid_report *report)
{
        struct mt_report_data *rdata;
        struct hid_field *field;
        int r, n;

        rdata = devm_kzalloc(&td->hdev->dev, sizeof(*rdata), GFP_KERNEL);
        if (!rdata)
                return NULL;

        rdata->report = report;
        rdata->application = mt_find_application(td, report);

        if (!rdata->application) {
                devm_kfree(&td->hdev->dev, rdata);
                return NULL;
        }

        for (r = 0; r < report->maxfield; r++) {
                field = report->field[r];

                if (!(HID_MAIN_ITEM_VARIABLE & field->flags))
                        continue;

                for (n = 0; n < field->report_count; n++) {
                        if (field->usage[n].hid == HID_DG_CONTACTID)
                                rdata->is_mt_collection = true;
                }
        }

        list_add_tail(&rdata->list, &td->reports);

        return rdata;
}

static struct mt_report_data *mt_find_report_data(struct mt_device *td,
                                                  struct hid_report *report)
{
        struct mt_report_data *tmp, *rdata = NULL;

        list_for_each_entry(tmp, &td->reports, list) {
                if (report == tmp->report) {
                        rdata = tmp;
                        break;
                }
        }

        if (!rdata)
                rdata = mt_allocate_report_data(td, report);

        return rdata;
}

static void mt_store_field(struct hid_device *hdev,
                           struct mt_application *application,
                           __s32 *value,
                           size_t offset)
{
        struct mt_usages *usage;
        __s32 **target;

        if (list_empty(&application->mt_usages))
                usage = mt_allocate_usage(hdev, application);
        else
                usage = list_last_entry(&application->mt_usages,
                                        struct mt_usages,
                                        list);

        if (!usage)
                return;

        target = (__s32 **)((char *)usage + offset);

        /* the value has already been filled, create a new slot */
        if (*target != DEFAULT_TRUE &&
            *target != DEFAULT_FALSE &&
            *target != DEFAULT_ZERO) {
                if (usage->contactid == DEFAULT_ZERO ||
                    usage->x == DEFAULT_ZERO ||
                    usage->y == DEFAULT_ZERO) {
                        hid_dbg(hdev,
                                "ignoring duplicate usage on incomplete");
                        return;
                }
                usage = mt_allocate_usage(hdev, application);
                if (!usage)
                        return;

                target = (__s32 **)((char *)usage + offset);
        }

        *target = value;
}

#define MT_STORE_FIELD(__name)                                          \
        mt_store_field(hdev, app,                                       \
                       &field->value[usage->usage_index],               \
                       offsetof(struct mt_usages, __name))

static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max, struct mt_application *app)
{
        struct mt_device *td = hid_get_drvdata(hdev);
        struct mt_class *cls = &td->mtclass;
        int code;
        struct hid_usage *prev_usage = NULL;

        /*
         * Model touchscreens providing buttons as touchpads.
         */
        if (field->application == HID_DG_TOUCHSCREEN &&
            (usage->hid & HID_USAGE_PAGE) == HID_UP_BUTTON) {
                app->mt_flags |= INPUT_MT_POINTER;
                td->inputmode_value = MT_INPUTMODE_TOUCHPAD;
        }

        /* count the buttons on touchpads */
        if ((usage->hid & HID_USAGE_PAGE) == HID_UP_BUTTON)
                app->buttons_count++;

        if (usage->usage_index)
                prev_usage = &field->usage[usage->usage_index - 1];

        switch (usage->hid & HID_USAGE_PAGE) {

        case HID_UP_GENDESK:
                switch (usage->hid) {
                case HID_GD_X:
                        if (prev_usage && (prev_usage->hid == usage->hid)) {
                                code = ABS_MT_TOOL_X;
                                MT_STORE_FIELD(cx);
                        } else {
                                code = ABS_MT_POSITION_X;
                                MT_STORE_FIELD(x);
                        }

                        set_abs(hi->input, code, field, cls->sn_move);

                        /*
                         * A system multi-axis that exports X and Y has a high
                         * chance of being used directly on a surface
                         */
                        if (field->application == HID_GD_SYSTEM_MULTIAXIS) {
                                __set_bit(INPUT_PROP_DIRECT,
                                          hi->input->propbit);
                                input_set_abs_params(hi->input,
                                                     ABS_MT_TOOL_TYPE,
                                                     MT_TOOL_DIAL,
                                                     MT_TOOL_DIAL, 0, 0);
                        }

                        return 1;
                case HID_GD_Y:
                        if (prev_usage && (prev_usage->hid == usage->hid)) {
                                code = ABS_MT_TOOL_Y;
                                MT_STORE_FIELD(cy);
                        } else {
                                code = ABS_MT_POSITION_Y;
                                MT_STORE_FIELD(y);
                        }

                        set_abs(hi->input, code, field, cls->sn_move);

                        return 1;
                }
                return 0;

        case HID_UP_DIGITIZER:
                switch (usage->hid) {
                case HID_DG_INRANGE:
                        if (app->quirks & MT_QUIRK_HOVERING) {
                                input_set_abs_params(hi->input,
                                        ABS_MT_DISTANCE, 0, 1, 0, 0);
                        }
                        MT_STORE_FIELD(inrange_state);
                        return 1;
                case HID_DG_CONFIDENCE:
                        if ((cls->name == MT_CLS_WIN_8 ||
                             cls->name == MT_CLS_WIN_8_FORCE_MULTI_INPUT) &&
                                (field->application == HID_DG_TOUCHPAD ||
                                 field->application == HID_DG_TOUCHSCREEN))
                                app->quirks |= MT_QUIRK_CONFIDENCE;

                        if (app->quirks & MT_QUIRK_CONFIDENCE)
                                input_set_abs_params(hi->input,
                                                     ABS_MT_TOOL_TYPE,
                                                     MT_TOOL_FINGER,
                                                     MT_TOOL_PALM, 0, 0);

                        MT_STORE_FIELD(confidence_state);
                        return 1;
                case HID_DG_TIPSWITCH:
                        if (field->application != HID_GD_SYSTEM_MULTIAXIS)
                                input_set_capability(hi->input,
                                                     EV_KEY, BTN_TOUCH);
                        MT_STORE_FIELD(tip_state);
                        return 1;
                case HID_DG_CONTACTID:
                        MT_STORE_FIELD(contactid);
                        app->touches_by_report++;
                        return 1;
                case HID_DG_WIDTH:
                        if (!(app->quirks & MT_QUIRK_NO_AREA))
                                set_abs(hi->input, ABS_MT_TOUCH_MAJOR, field,
                                        cls->sn_width);
                        MT_STORE_FIELD(w);
                        return 1;
                case HID_DG_HEIGHT:
                        if (!(app->quirks & MT_QUIRK_NO_AREA)) {
                                set_abs(hi->input, ABS_MT_TOUCH_MINOR, field,
                                        cls->sn_height);

                                /*
                                 * Only set ABS_MT_ORIENTATION if it is not
                                 * already set by the HID_DG_AZIMUTH usage.
                                 */
                                if (!test_bit(ABS_MT_ORIENTATION,
                                                hi->input->absbit))
                                        input_set_abs_params(hi->input,
                                                ABS_MT_ORIENTATION, 0, 1, 0, 0);
                        }
                        MT_STORE_FIELD(h);
                        return 1;
                case HID_DG_TIPPRESSURE:
                        set_abs(hi->input, ABS_MT_PRESSURE, field,
                                cls->sn_pressure);
                        MT_STORE_FIELD(p);
                        return 1;
                case HID_DG_SCANTIME:
                        input_set_capability(hi->input, EV_MSC, MSC_TIMESTAMP);
                        app->scantime = &field->value[usage->usage_index];
                        app->scantime_logical_max = field->logical_maximum;
                        return 1;
                case HID_DG_CONTACTCOUNT:
                        app->have_contact_count = true;
                        app->raw_cc = &field->value[usage->usage_index];
                        return 1;
                case HID_DG_AZIMUTH:
                        /*
                         * Azimuth has the range of [0, MAX) representing a full
                         * revolution. Set ABS_MT_ORIENTATION to a quarter of
                         * MAX according the definition of ABS_MT_ORIENTATION
                         */
                        input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
                                -field->logical_maximum / 4,
                                field->logical_maximum / 4,
                                cls->sn_move ?
                                field->logical_maximum / cls->sn_move : 0, 0);
                        MT_STORE_FIELD(a);
                        return 1;
                case HID_DG_CONTACTMAX:
                        /* contact max are global to the report */
                        return -1;
                case HID_DG_TOUCH:
                        /* Legacy devices use TIPSWITCH and not TOUCH.
                         * Let's just ignore this field. */
                        return -1;
                }
                /* let hid-input decide for the others */
                return 0;

        case HID_UP_BUTTON:
                code = BTN_MOUSE + ((usage->hid - 1) & HID_USAGE);
                /*
                 * MS PTP spec says that external buttons left and right have
                 * usages 2 and 3.
                 */
                if ((app->quirks & MT_QUIRK_WIN8_PTP_BUTTONS) &&
                    field->application == HID_DG_TOUCHPAD &&
                    (usage->hid & HID_USAGE) > 1)
                        code--;

                if (field->application == HID_GD_SYSTEM_MULTIAXIS)
                        code = BTN_0  + ((usage->hid - 1) & HID_USAGE);

                hid_map_usage(hi, usage, bit, max, EV_KEY, code);
                if (!*bit)
                        return -1;
                input_set_capability(hi->input, EV_KEY, code);
                return 1;

        case 0xff000000:
                /* we do not want to map these: no input-oriented meaning */
                return -1;
        }

        return 0;
}

static int mt_compute_slot(struct mt_device *td, struct mt_application *app,
                           struct mt_usages *slot,
                           struct input_dev *input)
{
        __s32 quirks = app->quirks;

        if (quirks & MT_QUIRK_SLOT_IS_CONTACTID)
                return *slot->contactid;

        if (quirks & MT_QUIRK_CYPRESS)
                return cypress_compute_slot(app, slot);

        if (quirks & MT_QUIRK_SLOT_IS_CONTACTNUMBER)
                return app->num_received;

        if (quirks & MT_QUIRK_SLOT_IS_CONTACTID_MINUS_ONE)
                return *slot->contactid - 1;

        return input_mt_get_slot_by_key(input, *slot->contactid);
}

static void mt_release_pending_palms(struct mt_device *td,
                                     struct mt_application *app,
                                     struct input_dev *input)
{
        int slotnum;
        bool need_sync = false;

        for_each_set_bit(slotnum, app->pending_palm_slots, td->maxcontacts) {
                clear_bit(slotnum, app->pending_palm_slots);

                input_mt_slot(input, slotnum);
                input_mt_report_slot_inactive(input);

                need_sync = true;
        }

        if (need_sync) {
                input_mt_sync_frame(input);
                input_sync(input);
        }
}

/*
 * this function is called when a whole packet has been received and processed,
 * so that it can decide what to send to the input layer.
 */
static void mt_sync_frame(struct mt_device *td, struct mt_application *app,
                          struct input_dev *input)
{
        if (app->quirks & MT_QUIRK_WIN8_PTP_BUTTONS)
                input_event(input, EV_KEY, BTN_LEFT, app->left_button_state);

        input_mt_sync_frame(input);
        input_event(input, EV_MSC, MSC_TIMESTAMP, app->timestamp);
        input_sync(input);

        mt_release_pending_palms(td, app, input);

        app->num_received = 0;
        app->left_button_state = 0;

        if (test_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags))
                set_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags);
        else
                clear_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags);
        clear_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags);
}

static int mt_compute_timestamp(struct mt_application *app, __s32 value)
{
        long delta = value - app->prev_scantime;
        unsigned long jdelta = jiffies_to_usecs(jiffies - app->jiffies);

        app->jiffies = jiffies;

        if (delta < 0)
                delta += app->scantime_logical_max;

        /* HID_DG_SCANTIME is expressed in 100us, we want it in us. */
        delta *= 100;

        if (jdelta > MAX_TIMESTAMP_INTERVAL)
                /* No data received for a while, resync the timestamp. */
                return 0;
        else
                return app->timestamp + delta;
}

static int mt_touch_event(struct hid_device *hid, struct hid_field *field,
                                struct hid_usage *usage, __s32 value)
{
        /* we will handle the hidinput part later, now remains hiddev */
        if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
                hid->hiddev_hid_event(hid, field, usage, value);

        return 1;
}

static int mt_process_slot(struct mt_device *td, struct input_dev *input,
                            struct mt_application *app,
                            struct mt_usages *slot)
{
        struct input_mt *mt = input->mt;
        __s32 quirks = app->quirks;
        bool valid = true;
        bool confidence_state = true;
        bool inrange_state = false;
        int active;
        int slotnum;
        int tool = MT_TOOL_FINGER;

        if (!slot)
                return -EINVAL;

        if ((quirks & MT_QUIRK_CONTACT_CNT_ACCURATE) &&
            app->num_received >= app->num_expected)
                return -EAGAIN;

        if (!(quirks & MT_QUIRK_ALWAYS_VALID)) {
                if (quirks & MT_QUIRK_VALID_IS_INRANGE)
                        valid = *slot->inrange_state;
                if (quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
                        valid = *slot->tip_state;
                if (quirks & MT_QUIRK_VALID_IS_CONFIDENCE)
                        valid = *slot->confidence_state;

                if (!valid)

                        return 0;
        }

        slotnum = mt_compute_slot(td, app, slot, input);
        if (slotnum < 0 || slotnum >= td->maxcontacts)
                return 0;

        if ((quirks & MT_QUIRK_IGNORE_DUPLICATES) && mt) {
                struct input_mt_slot *i_slot = &mt->slots[slotnum];

                if (input_mt_is_active(i_slot) &&
                    input_mt_is_used(mt, i_slot))
                        return -EAGAIN;
        }

        if (quirks & MT_QUIRK_CONFIDENCE)
                confidence_state = *slot->confidence_state;

        if (quirks & MT_QUIRK_HOVERING)
                inrange_state = *slot->inrange_state;

        active = *slot->tip_state || inrange_state;

        if (app->application == HID_GD_SYSTEM_MULTIAXIS)
                tool = MT_TOOL_DIAL;
        else if (unlikely(!confidence_state)) {
                tool = MT_TOOL_PALM;
                if (!active && mt &&
                    input_mt_is_active(&mt->slots[slotnum])) {
                        /*
                         * The non-confidence was reported for
                         * previously valid contact that is also no
                         * longer valid. We can't simply report
                         * lift-off as userspace will not be aware
                         * of non-confidence, so we need to split
                         * it into 2 events: active MT_TOOL_PALM
                         * and a separate liftoff.
                         */
                        active = true;
                        set_bit(slotnum, app->pending_palm_slots);
                }
        }

        input_mt_slot(input, slotnum);
        input_mt_report_slot_state(input, tool, active);
        if (active) {
                /* this finger is in proximity of the sensor */
                int wide = (*slot->w > *slot->h);
                int major = max(*slot->w, *slot->h);
                int minor = min(*slot->w, *slot->h);
                int orientation = wide;
                int max_azimuth;
                int azimuth;

                if (slot->a != DEFAULT_ZERO) {
                        /*
                         * Azimuth is counter-clockwise and ranges from [0, MAX)
                         * (a full revolution). Convert it to clockwise ranging
                         * [-MAX/2, MAX/2].
                         *
                         * Note that ABS_MT_ORIENTATION require us to report
                         * the limit of [-MAX/4, MAX/4], but the value can go
                         * out of range to [-MAX/2, MAX/2] to report an upside
                         * down ellipsis.
                         */
                        azimuth = *slot->a;
                        max_azimuth = input_abs_get_max(input,
                                                        ABS_MT_ORIENTATION);
                        if (azimuth > max_azimuth * 2)
                                azimuth -= max_azimuth * 4;
                        orientation = -azimuth;
                }

                if (quirks & MT_QUIRK_TOUCH_SIZE_SCALING) {
                        /*
                         * divided by two to match visual scale of touch
                         * for devices with this quirk
                         */
                        major = major >> 1;
                        minor = minor >> 1;
                }

                input_event(input, EV_ABS, ABS_MT_POSITION_X, *slot->x);
                input_event(input, EV_ABS, ABS_MT_POSITION_Y, *slot->y);
                input_event(input, EV_ABS, ABS_MT_TOOL_X, *slot->cx);
                input_event(input, EV_ABS, ABS_MT_TOOL_Y, *slot->cy);
                input_event(input, EV_ABS, ABS_MT_DISTANCE, !*slot->tip_state);
                input_event(input, EV_ABS, ABS_MT_ORIENTATION, orientation);
                input_event(input, EV_ABS, ABS_MT_PRESSURE, *slot->p);
                input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
                input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);

                set_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags);
        }

        return 0;
}

static void mt_process_mt_event(struct hid_device *hid,
                                struct mt_application *app,
                                struct hid_field *field,
                                struct hid_usage *usage,
                                __s32 value,
                                bool first_packet)
{
        __s32 quirks = app->quirks;
        struct input_dev *input = field->hidinput->input;

        if (!usage->type || !(hid->claimed & HID_CLAIMED_INPUT))
                return;

        if (quirks & MT_QUIRK_WIN8_PTP_BUTTONS) {

                /*
                 * For Win8 PTP touchpads we should only look at
                 * non finger/touch events in the first_packet of a
                 * (possible) multi-packet frame.
                 */
                if (!first_packet)
                        return;

                /*
                 * For Win8 PTP touchpads we map both the clickpad click
                 * and any "external" left buttons to BTN_LEFT if a
                 * device claims to have both we need to report 1 for
                 * BTN_LEFT if either is pressed, so we or all values
                 * together and report the result in mt_sync_frame().
                 */
                if (usage->type == EV_KEY && usage->code == BTN_LEFT) {
                        app->left_button_state |= value;
                        return;
                }
        }

        input_event(input, usage->type, usage->code, value);
}

static void mt_touch_report(struct hid_device *hid,
                            struct mt_report_data *rdata)
{
        struct mt_device *td = hid_get_drvdata(hid);
        struct hid_report *report = rdata->report;
        struct mt_application *app = rdata->application;
        struct hid_field *field;
        struct input_dev *input;
        struct mt_usages *slot;
        bool first_packet;
        unsigned count;
        int r, n;
        int scantime = 0;
        int contact_count = -1;

        /* sticky fingers release in progress, abort */
        if (test_and_set_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags))
                return;

        scantime = *app->scantime;
        app->timestamp = mt_compute_timestamp(app, scantime);
        if (app->raw_cc != DEFAULT_ZERO)
                contact_count = *app->raw_cc;

        /*
         * Includes multi-packet support where subsequent
         * packets are sent with zero contactcount.
         */
        if (contact_count >= 0) {
                /*
                 * For Win8 PTPs the first packet (td->num_received == 0) may
                 * have a contactcount of 0 if there only is a button event.
                 * We double check that this is not a continuation packet
                 * of a possible multi-packet frame be checking that the
                 * timestamp has changed.
                 */
                if ((app->quirks & MT_QUIRK_WIN8_PTP_BUTTONS) &&
                    app->num_received == 0 &&
                    app->prev_scantime != scantime)
                        app->num_expected = contact_count;
                /* A non 0 contact count always indicates a first packet */
                else if (contact_count)
                        app->num_expected = contact_count;
        }
        app->prev_scantime = scantime;

        first_packet = app->num_received == 0;

        input = report->field[0]->hidinput->input;

        list_for_each_entry(slot, &app->mt_usages, list) {
                if (!mt_process_slot(td, input, app, slot))
                        app->num_received++;
        }

        for (r = 0; r < report->maxfield; r++) {
                field = report->field[r];
                count = field->report_count;

                if (!(HID_MAIN_ITEM_VARIABLE & field->flags))
                        continue;

                for (n = 0; n < count; n++)
                        mt_process_mt_event(hid, app, field,
                                            &field->usage[n], field->value[n],
                                            first_packet);
        }

        if (app->num_received >= app->num_expected)
                mt_sync_frame(td, app, input);

        /*
         * Windows 8 specs says 2 things:
         * - once a contact has been reported, it has to be reported in each
         *   subsequent report
         * - the report rate when fingers are present has to be at least
         *   the refresh rate of the screen, 60 or 120 Hz
         *
         * I interprete this that the specification forces a report rate of
         * at least 60 Hz for a touchscreen to be certified.
         * Which means that if we do not get a report whithin 16 ms, either
         * something wrong happens, either the touchscreen forgets to send
         * a release. Taking a reasonable margin allows to remove issues
         * with USB communication or the load of the machine.
         *
         * Given that Win 8 devices are forced to send a release, this will
         * only affect laggish machines and the ones that have a firmware
         * defect.
         */
        if (app->quirks & MT_QUIRK_STICKY_FINGERS) {
                if (test_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags))
                        mod_timer(&td->release_timer,
                                  jiffies + msecs_to_jiffies(100));
                else
                        del_timer(&td->release_timer);
        }

        clear_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags);
}

static int mt_touch_input_configured(struct hid_device *hdev,
                                     struct hid_input *hi,
                                     struct mt_application *app)
{
        struct mt_device *td = hid_get_drvdata(hdev);
        struct mt_class *cls = &td->mtclass;
        struct input_dev *input = hi->input;
        int ret;

        if (!td->maxcontacts)
                td->maxcontacts = MT_DEFAULT_MAXCONTACT;

        mt_post_parse(td, app);
        if (td->serial_maybe)
                mt_post_parse_default_settings(td, app);

        if (cls->is_indirect)
                app->mt_flags |= INPUT_MT_POINTER;

        if (app->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
                app->mt_flags |= INPUT_MT_DROP_UNUSED;

        /* check for clickpads */
        if ((app->mt_flags & INPUT_MT_POINTER) &&
            (app->buttons_count == 1))
                td->is_buttonpad = true;

        if (td->is_buttonpad)
                __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);

        app->pending_palm_slots = devm_kcalloc(&hi->input->dev,
                                               BITS_TO_LONGS(td->maxcontacts),
                                               sizeof(long),
                                               GFP_KERNEL);
        if (!app->pending_palm_slots)
                return -ENOMEM;

        ret = input_mt_init_slots(input, td->maxcontacts, app->mt_flags);
        if (ret)
                return ret;

        app->mt_flags = 0;
        return 0;
}

#define mt_map_key_clear(c)     hid_map_usage_clear(hi, usage, bit, \
                                                    max, EV_KEY, (c))
static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max)
{
        struct mt_device *td = hid_get_drvdata(hdev);
        struct mt_application *application;
        struct mt_report_data *rdata;

        rdata = mt_find_report_data(td, field->report);
        if (!rdata) {
                hid_err(hdev, "failed to allocate data for report\n");
                return 0;
        }

        application = rdata->application;

        /*
         * If mtclass.export_all_inputs is not set, only map fields from
         * TouchScreen or TouchPad collections. We need to ignore fields
         * that belong to other collections such as Mouse that might have
         * the same GenericDesktop usages.
         */
        if (!td->mtclass.export_all_inputs &&
            field->application != HID_DG_TOUCHSCREEN &&
            field->application != HID_DG_PEN &&
            field->application != HID_DG_TOUCHPAD &&
            field->application != HID_GD_KEYBOARD &&
            field->application != HID_GD_SYSTEM_CONTROL &&
            field->application != HID_CP_CONSUMER_CONTROL &&
            field->application != HID_GD_WIRELESS_RADIO_CTLS &&
            field->application != HID_GD_SYSTEM_MULTIAXIS &&
            !(field->application == HID_VD_ASUS_CUSTOM_MEDIA_KEYS &&
              application->quirks & MT_QUIRK_ASUS_CUSTOM_UP))
                return -1;

        /*
         * Some Asus keyboard+touchpad devices have the hotkeys defined in the
         * touchpad report descriptor. We need to treat these as an array to
         * map usages to input keys.
         */
        if (field->application == HID_VD_ASUS_CUSTOM_MEDIA_KEYS &&
            application->quirks & MT_QUIRK_ASUS_CUSTOM_UP &&
            (usage->hid & HID_USAGE_PAGE) == HID_UP_CUSTOM) {
                set_bit(EV_REP, hi->input->evbit);
                if (field->flags & HID_MAIN_ITEM_VARIABLE)
                        field->flags &= ~HID_MAIN_ITEM_VARIABLE;
                switch (usage->hid & HID_USAGE) {
                case 0x10: mt_map_key_clear(KEY_BRIGHTNESSDOWN);        break;
                case 0x20: mt_map_key_clear(KEY_BRIGHTNESSUP);          break;
                case 0x35: mt_map_key_clear(KEY_DISPLAY_OFF);           break;
                case 0x6b: mt_map_key_clear(KEY_F21);                   break;
                case 0x6c: mt_map_key_clear(KEY_SLEEP);                 break;
                default:
                        return -1;
                }
                return 1;
        }

        if (rdata->is_mt_collection)
                return mt_touch_input_mapping(hdev, hi, field, usage, bit, max,
                                              application);

        /*
         * some egalax touchscreens have "application == DG_TOUCHSCREEN"
         * for the stylus. Overwrite the hid_input application
         */
        if (field->physical == HID_DG_STYLUS)
                hi->application = HID_DG_STYLUS;

        /* let hid-core decide for the others */
        return 0;
}

static int mt_input_mapped(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max)
{
        struct mt_device *td = hid_get_drvdata(hdev);
        struct mt_report_data *rdata;

        rdata = mt_find_report_data(td, field->report);
        if (rdata && rdata->is_mt_collection) {
                /* We own these mappings, tell hid-input to ignore them */
                return -1;
        }

        /* let hid-core decide for the others */
        return 0;
}

static int mt_event(struct hid_device *hid, struct hid_field *field,
                                struct hid_usage *usage, __s32 value)
{
        struct mt_device *td = hid_get_drvdata(hid);
        struct mt_report_data *rdata;

        rdata = mt_find_report_data(td, field->report);
        if (rdata && rdata->is_mt_collection)
                return mt_touch_event(hid, field, usage, value);

        return 0;
}

static void mt_report(struct hid_device *hid, struct hid_report *report)
{
        struct mt_device *td = hid_get_drvdata(hid);
        struct hid_field *field = report->field[0];
        struct mt_report_data *rdata;

        if (!(hid->claimed & HID_CLAIMED_INPUT))
                return;

        rdata = mt_find_report_data(td, report);
        if (rdata && rdata->is_mt_collection)
                return mt_touch_report(hid, rdata);

        if (field && field->hidinput && field->hidinput->input)
                input_sync(field->hidinput->input);
}

static bool mt_need_to_apply_feature(struct hid_device *hdev,
                                     struct hid_field *field,
                                     struct hid_usage *usage,
                                     enum latency_mode latency,
                                     bool surface_switch,
                                     bool button_switch,
                                     bool *inputmode_found)
{
        struct mt_device *td = hid_get_drvdata(hdev);
        struct mt_class *cls = &td->mtclass;
        struct hid_report *report = field->report;
        unsigned int index = usage->usage_index;
        char *buf;
        u32 report_len;
        int max;

        switch (usage->hid) {
        case HID_DG_INPUTMODE:
                /*
                 * Some elan panels wrongly declare 2 input mode features,
                 * and silently ignore when we set the value in the second
                 * field. Skip the second feature and hope for the best.
                 */
                if (*inputmode_found)
                        return false;

                if (cls->quirks & MT_QUIRK_FORCE_GET_FEATURE) {
                        report_len = hid_report_len(report);
                        buf = hid_alloc_report_buf(report, GFP_KERNEL);
                        if (!buf) {
                                hid_err(hdev,
                                        "failed to allocate buffer for report\n");
                                return false;
                        }
                        hid_hw_raw_request(hdev, report->id, buf, report_len,
                                           HID_FEATURE_REPORT,
                                           HID_REQ_GET_REPORT);
                        kfree(buf);
                }

                field->value[index] = td->inputmode_value;
                *inputmode_found = true;
                return true;

        case HID_DG_CONTACTMAX:
                if (cls->maxcontacts) {
                        max = min_t(int, field->logical_maximum,
                                    cls->maxcontacts);
                        if (field->value[index] != max) {
                                field->value[index] = max;
                                return true;
                        }
                }
                break;

        case HID_DG_LATENCYMODE:
                field->value[index] = latency;
                return true;

        case HID_DG_SURFACESWITCH:
                field->value[index] = surface_switch;
                return true;

        case HID_DG_BUTTONSWITCH:
                field->value[index] = button_switch;
                return true;
        }

        return false; /* no need to update the report */
}

static void mt_set_modes(struct hid_device *hdev, enum latency_mode latency,
                         bool surface_switch, bool button_switch)
{
        struct hid_report_enum *rep_enum;
        struct hid_report *rep;
        struct hid_usage *usage;
        int i, j;
        bool update_report;
        bool inputmode_found = false;

        rep_enum = &hdev->report_enum[HID_FEATURE_REPORT];
        list_for_each_entry(rep, &rep_enum->report_list, list) {
                update_report = false;

                for (i = 0; i < rep->maxfield; i++) {
                        /* Ignore if report count is out of bounds. */
                        if (rep->field[i]->report_count < 1)
                                continue;

                        for (j = 0; j < rep->field[i]->maxusage; j++) {
                                usage = &rep->field[i]->usage[j];

                                if (mt_need_to_apply_feature(hdev,
                                                             rep->field[i],
                                                             usage,
                                                             latency,
                                                             surface_switch,
                                                             button_switch,
                                                             &inputmode_found))
                                        update_report = true;
                        }
                }

                if (update_report)
                        hid_hw_request(hdev, rep, HID_REQ_SET_REPORT);
        }
}

static void mt_post_parse_default_settings(struct mt_device *td,
                                           struct mt_application *app)
{
        __s32 quirks = app->quirks;

        /* unknown serial device needs special quirks */
        if (list_is_singular(&app->mt_usages)) {
                quirks |= MT_QUIRK_ALWAYS_VALID;
                quirks &= ~MT_QUIRK_NOT_SEEN_MEANS_UP;
                quirks &= ~MT_QUIRK_VALID_IS_INRANGE;
                quirks &= ~MT_QUIRK_VALID_IS_CONFIDENCE;
                quirks &= ~MT_QUIRK_CONTACT_CNT_ACCURATE;
        }

        app->quirks = quirks;
}

static void mt_post_parse(struct mt_device *td, struct mt_application *app)
{
        if (!app->have_contact_count)
                app->quirks &= ~MT_QUIRK_CONTACT_CNT_ACCURATE;
}

static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
{
        struct mt_device *td = hid_get_drvdata(hdev);
        char *name;
        const char *suffix = NULL;
        struct mt_report_data *rdata;
        struct mt_application *mt_application = NULL;
        struct hid_report *report;
        int ret;

        list_for_each_entry(report, &hi->reports, hidinput_list) {
                rdata = mt_find_report_data(td, report);
                if (!rdata) {
                        hid_err(hdev, "failed to allocate data for report\n");
                        return -ENOMEM;
                }

                mt_application = rdata->application;

                if (rdata->is_mt_collection) {
                        ret = mt_touch_input_configured(hdev, hi,
                                                        mt_application);
                        if (ret)
                                return ret;
                }
        }

        switch (hi->application) {
        case HID_GD_KEYBOARD:
        case HID_GD_KEYPAD:
        case HID_GD_MOUSE:
        case HID_DG_TOUCHPAD:
        case HID_GD_SYSTEM_CONTROL:
        case HID_CP_CONSUMER_CONTROL:
        case HID_GD_WIRELESS_RADIO_CTLS:
        case HID_GD_SYSTEM_MULTIAXIS:
                /* already handled by hid core */
                break;
        case HID_DG_TOUCHSCREEN:
                /* we do not set suffix = "Touchscreen" */
                hi->input->name = hdev->name;
                break;
        case HID_DG_STYLUS:
                /* force BTN_STYLUS to allow tablet matching in udev */
                __set_bit(BTN_STYLUS, hi->input->keybit);
                break;
        case HID_VD_ASUS_CUSTOM_MEDIA_KEYS:
                suffix = "Custom Media Keys";
                break;
        case HID_DG_PEN:
                suffix = "Stylus";
                break;
        default:
                suffix = "UNKNOWN";
                break;
        }

        if (suffix) {
                name = devm_kzalloc(&hi->input->dev,
                                    strlen(hdev->name) + strlen(suffix) + 2,
                                    GFP_KERNEL);
                if (name) {
                        sprintf(name, "%s %s", hdev->name, suffix);
                        hi->input->name = name;
                }
        }

        return 0;
}

static void mt_fix_const_field(struct hid_field *field, unsigned int usage)
{
        if (field->usage[0].hid != usage ||
            !(field->flags & HID_MAIN_ITEM_CONSTANT))
                return;

        field->flags &= ~HID_MAIN_ITEM_CONSTANT;
        field->flags |= HID_MAIN_ITEM_VARIABLE;
}

static void mt_fix_const_fields(struct hid_device *hdev, unsigned int usage)
{
        struct hid_report *report;
        int i;

        list_for_each_entry(report,
                            &hdev->report_enum[HID_INPUT_REPORT].report_list,
                            list) {

                if (!report->maxfield)
                        continue;

                for (i = 0; i < report->maxfield; i++)
                        if (report->field[i]->maxusage >= 1)
                                mt_fix_const_field(report->field[i], usage);
        }
}

static void mt_release_contacts(struct hid_device *hid)
{
        struct hid_input *hidinput;
        struct mt_application *application;
        struct mt_device *td = hid_get_drvdata(hid);

        list_for_each_entry(hidinput, &hid->inputs, list) {
                struct input_dev *input_dev = hidinput->input;
                struct input_mt *mt = input_dev->mt;
                int i;

                if (mt) {
                        for (i = 0; i < mt->num_slots; i++) {
                                input_mt_slot(input_dev, i);
                                input_mt_report_slot_inactive(input_dev);
                        }
                        input_mt_sync_frame(input_dev);
                        input_sync(input_dev);
                }
        }

        list_for_each_entry(application, &td->applications, list) {
                application->num_received = 0;
        }
}

static void mt_expired_timeout(struct timer_list *t)
{
        struct mt_device *td = from_timer(td, t, release_timer);
        struct hid_device *hdev = td->hdev;

        /*
         * An input report came in just before we release the sticky fingers,
         * it will take care of the sticky fingers.
         */
        if (test_and_set_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags))
                return;
        if (test_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags))
                mt_release_contacts(hdev);
        clear_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags);
}

static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
        int ret, i;
        struct mt_device *td;
        const struct mt_class *mtclass = mt_classes; /* MT_CLS_DEFAULT */

        for (i = 0; mt_classes[i].name ; i++) {
                if (id->driver_data == mt_classes[i].name) {
                        mtclass = &(mt_classes[i]);
                        break;
                }
        }

        td = devm_kzalloc(&hdev->dev, sizeof(struct mt_device), GFP_KERNEL);
        if (!td) {
                dev_err(&hdev->dev, "cannot allocate multitouch data\n");
                return -ENOMEM;
        }
        td->hdev = hdev;
        td->mtclass = *mtclass;
        td->inputmode_value = MT_INPUTMODE_TOUCHSCREEN;
        hid_set_drvdata(hdev, td);

        INIT_LIST_HEAD(&td->applications);
        INIT_LIST_HEAD(&td->reports);

        if (id->vendor == HID_ANY_ID && id->product == HID_ANY_ID)
                td->serial_maybe = true;

        /* This allows the driver to correctly support devices
         * that emit events over several HID messages.
         */
        hdev->quirks |= HID_QUIRK_NO_INPUT_SYNC;

        /*
         * This allows the driver to handle different input sensors
         * that emits events through different applications on the same HID
         * device.
         */
        hdev->quirks |= HID_QUIRK_INPUT_PER_APP;

        if (id->group != HID_GROUP_MULTITOUCH_WIN_8)
                hdev->quirks |= HID_QUIRK_MULTI_INPUT;

        if (mtclass->quirks & MT_QUIRK_FORCE_MULTI_INPUT) {
                hdev->quirks &= ~HID_QUIRK_INPUT_PER_APP;
                hdev->quirks |= HID_QUIRK_MULTI_INPUT;
        }

        timer_setup(&td->release_timer, mt_expired_timeout, 0);

        ret = hid_parse(hdev);
        if (ret != 0)
                return ret;

        if (mtclass->quirks & MT_QUIRK_FIX_CONST_CONTACT_ID)
                mt_fix_const_fields(hdev, HID_DG_CONTACTID);

        ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
        if (ret)
                return ret;

        ret = sysfs_create_group(&hdev->dev.kobj, &mt_attribute_group);
        if (ret)
                dev_warn(&hdev->dev, "Cannot allocate sysfs group for %s\n",
                                hdev->name);

        mt_set_modes(hdev, HID_LATENCY_NORMAL, true, true);

        return 0;
}

#ifdef CONFIG_PM
static int mt_suspend(struct hid_device *hdev, pm_message_t state)
{
        /* High latency is desirable for power savings during S3/S0ix */
        mt_set_modes(hdev, HID_LATENCY_HIGH, true, true);
        return 0;
}

static int mt_reset_resume(struct hid_device *hdev)
{
        mt_release_contacts(hdev);
        mt_set_modes(hdev, HID_LATENCY_NORMAL, true, true);
        return 0;
}

static int mt_resume(struct hid_device *hdev)
{
        /* Some Elan legacy devices require SET_IDLE to be set on resume.
         * It should be safe to send it to other devices too.
         * Tested on 3M, Stantum, Cypress, Zytronic, eGalax, and Elan panels. */

        hid_hw_idle(hdev, 0, 0, HID_REQ_SET_IDLE);

        mt_set_modes(hdev, HID_LATENCY_NORMAL, true, true);

        return 0;
}
#endif

static void mt_remove(struct hid_device *hdev)
{
        struct mt_device *td = hid_get_drvdata(hdev);

        del_timer_sync(&td->release_timer);

        sysfs_remove_group(&hdev->dev.kobj, &mt_attribute_group);
        hid_hw_stop(hdev);
}

/*
 * This list contains only:
 * - VID/PID of products not working with the default multitouch handling
 * - 2 generic rules.
 * So there is no point in adding here any device with MT_CLS_DEFAULT.
 */
static const struct hid_device_id mt_devices[] = {

        /* 3M panels */
        { .driver_data = MT_CLS_3M,
                MT_USB_DEVICE(USB_VENDOR_ID_3M,
                        USB_DEVICE_ID_3M1968) },
        { .driver_data = MT_CLS_3M,
                MT_USB_DEVICE(USB_VENDOR_ID_3M,
                        USB_DEVICE_ID_3M2256) },
        { .driver_data = MT_CLS_3M,
                MT_USB_DEVICE(USB_VENDOR_ID_3M,
                        USB_DEVICE_ID_3M3266) },

        /* Anton devices */
        { .driver_data = MT_CLS_EXPORT_ALL_INPUTS,
                MT_USB_DEVICE(USB_VENDOR_ID_ANTON,
                        USB_DEVICE_ID_ANTON_TOUCH_PAD) },

        /* Asus T304UA */
        { .driver_data = MT_CLS_ASUS,
                HID_DEVICE(BUS_USB, HID_GROUP_MULTITOUCH_WIN_8,
                        USB_VENDOR_ID_ASUSTEK,
                        USB_DEVICE_ID_ASUSTEK_T304_KEYBOARD) },

        /* Atmel panels */
        { .driver_data = MT_CLS_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_ATMEL,
                        USB_DEVICE_ID_ATMEL_MXT_DIGITIZER) },

        /* Baanto multitouch devices */
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_BAANTO,
                        USB_DEVICE_ID_BAANTO_MT_190W2) },

        /* Cando panels */
        { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
                MT_USB_DEVICE(USB_VENDOR_ID_CANDO,
                        USB_DEVICE_ID_CANDO_MULTI_TOUCH) },
        { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
                MT_USB_DEVICE(USB_VENDOR_ID_CANDO,
                        USB_DEVICE_ID_CANDO_MULTI_TOUCH_15_6) },

        /* Chunghwa Telecom touch panels */
        {  .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_CHUNGHWAT,
                        USB_DEVICE_ID_CHUNGHWAT_MULTITOUCH) },

        /* CJTouch panels */
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_CJTOUCH,
                        USB_DEVICE_ID_CJTOUCH_MULTI_TOUCH_0020) },
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_CJTOUCH,
                        USB_DEVICE_ID_CJTOUCH_MULTI_TOUCH_0040) },

        /* CVTouch panels */
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_CVTOUCH,
                        USB_DEVICE_ID_CVTOUCH_SCREEN) },

        /* eGalax devices (resistive) */
        { .driver_data = MT_CLS_EGALAX,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_480D) },
        { .driver_data = MT_CLS_EGALAX,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_480E) },

        /* eGalax devices (capacitive) */
        { .driver_data = MT_CLS_EGALAX_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7207) },
        { .driver_data = MT_CLS_EGALAX,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_720C) },
        { .driver_data = MT_CLS_EGALAX_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7224) },
        { .driver_data = MT_CLS_EGALAX_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_722A) },
        { .driver_data = MT_CLS_EGALAX_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_725E) },
        { .driver_data = MT_CLS_EGALAX_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7262) },
        { .driver_data = MT_CLS_EGALAX,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_726B) },
        { .driver_data = MT_CLS_EGALAX,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_72A1) },
        { .driver_data = MT_CLS_EGALAX_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_72AA) },
        { .driver_data = MT_CLS_EGALAX,
                HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_72C4) },
        { .driver_data = MT_CLS_EGALAX,
                HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_72D0) },
        { .driver_data = MT_CLS_EGALAX,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_72FA) },
        { .driver_data = MT_CLS_EGALAX,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7302) },
        { .driver_data = MT_CLS_EGALAX_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7349) },
        { .driver_data = MT_CLS_EGALAX_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_73F7) },
        { .driver_data = MT_CLS_EGALAX_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_A001) },
        { .driver_data = MT_CLS_EGALAX,
                MT_USB_DEVICE(USB_VENDOR_ID_DWAV,
                        USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_C002) },

        /* Elan devices */
        { .driver_data = MT_CLS_WIN_8_FORCE_MULTI_INPUT,
                HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
                        USB_VENDOR_ID_ELAN, 0x313a) },

        /* Elitegroup panel */
        { .driver_data = MT_CLS_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_ELITEGROUP,
                        USB_DEVICE_ID_ELITEGROUP_05D8) },

        /* Flatfrog Panels */
        { .driver_data = MT_CLS_FLATFROG,
                MT_USB_DEVICE(USB_VENDOR_ID_FLATFROG,
                        USB_DEVICE_ID_MULTITOUCH_3200) },

        /* FocalTech Panels */
        { .driver_data = MT_CLS_SERIAL,
                MT_USB_DEVICE(USB_VENDOR_ID_CYGNAL,
                        USB_DEVICE_ID_FOCALTECH_FTXXXX_MULTITOUCH) },

        /* GeneralTouch panel */
        { .driver_data = MT_CLS_GENERALTOUCH_TWOFINGERS,
                MT_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
                        USB_DEVICE_ID_GENERAL_TOUCH_WIN7_TWOFINGERS) },
        { .driver_data = MT_CLS_GENERALTOUCH_PWT_TENFINGERS,
                MT_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
                        USB_DEVICE_ID_GENERAL_TOUCH_WIN8_PWT_TENFINGERS) },
        { .driver_data = MT_CLS_GENERALTOUCH_TWOFINGERS,
                MT_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
                        USB_DEVICE_ID_GENERAL_TOUCH_WIN8_PIT_0101) },
        { .driver_data = MT_CLS_GENERALTOUCH_PWT_TENFINGERS,
                MT_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
                        USB_DEVICE_ID_GENERAL_TOUCH_WIN8_PIT_0102) },
        { .driver_data = MT_CLS_GENERALTOUCH_PWT_TENFINGERS,
                MT_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
                        USB_DEVICE_ID_GENERAL_TOUCH_WIN8_PIT_0106) },
        { .driver_data = MT_CLS_GENERALTOUCH_PWT_TENFINGERS,
                MT_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
                        USB_DEVICE_ID_GENERAL_TOUCH_WIN8_PIT_010A) },
        { .driver_data = MT_CLS_GENERALTOUCH_PWT_TENFINGERS,
                MT_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
                        USB_DEVICE_ID_GENERAL_TOUCH_WIN8_PIT_E100) },

        /* Gametel game controller */
        { .driver_data = MT_CLS_NSMU,
                MT_BT_DEVICE(USB_VENDOR_ID_FRUCTEL,
                        USB_DEVICE_ID_GAMETEL_MT_MODE) },

        /* GoodTouch panels */
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_GOODTOUCH,
                        USB_DEVICE_ID_GOODTOUCH_000f) },

        /* Hanvon panels */
        { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTID,
                MT_USB_DEVICE(USB_VENDOR_ID_HANVON_ALT,
                        USB_DEVICE_ID_HANVON_ALT_MULTITOUCH) },

        /* Ilitek dual touch panel */
        {  .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_ILITEK,
                        USB_DEVICE_ID_ILITEK_MULTITOUCH) },

        /* LG Melfas panel */
        { .driver_data = MT_CLS_LG,
                HID_USB_DEVICE(USB_VENDOR_ID_LG,
                        USB_DEVICE_ID_LG_MELFAS_MT) },
        { .driver_data = MT_CLS_LG,
                HID_DEVICE(BUS_I2C, HID_GROUP_GENERIC,
                        USB_VENDOR_ID_LG, I2C_DEVICE_ID_LG_7010) },

        /* Lenovo X1 TAB Gen 2 */
        { .driver_data = MT_CLS_WIN_8_FORCE_MULTI_INPUT,
                HID_DEVICE(BUS_USB, HID_GROUP_MULTITOUCH_WIN_8,
                           USB_VENDOR_ID_LENOVO,
                           USB_DEVICE_ID_LENOVO_X1_TAB) },

        /* Lenovo X1 TAB Gen 3 */
        { .driver_data = MT_CLS_WIN_8_FORCE_MULTI_INPUT,
                HID_DEVICE(BUS_USB, HID_GROUP_MULTITOUCH_WIN_8,
                           USB_VENDOR_ID_LENOVO,
                           USB_DEVICE_ID_LENOVO_X1_TAB3) },

        /* MosArt panels */
        { .driver_data = MT_CLS_CONFIDENCE_MINUS_ONE,
                MT_USB_DEVICE(USB_VENDOR_ID_ASUS,

                        USB_DEVICE_ID_ASUS_T91MT)},
        { .driver_data = MT_CLS_CONFIDENCE_MINUS_ONE,
                MT_USB_DEVICE(USB_VENDOR_ID_ASUS,
                        USB_DEVICE_ID_ASUSTEK_MULTITOUCH_YFO) },
        { .driver_data = MT_CLS_CONFIDENCE_MINUS_ONE,
                MT_USB_DEVICE(USB_VENDOR_ID_TURBOX,
                        USB_DEVICE_ID_TURBOX_TOUCHSCREEN_MOSART) },

        /* Novatek Panel */
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_NOVATEK,
                        USB_DEVICE_ID_NOVATEK_PCT) },

        /* Ntrig Panel */
        { .driver_data = MT_CLS_NSMU,
                HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
                        USB_VENDOR_ID_NTRIG, 0x1b05) },

        /* Panasonic panels */
        { .driver_data = MT_CLS_PANASONIC,
                MT_USB_DEVICE(USB_VENDOR_ID_PANASONIC,
                        USB_DEVICE_ID_PANABOARD_UBT780) },
        { .driver_data = MT_CLS_PANASONIC,
                MT_USB_DEVICE(USB_VENDOR_ID_PANASONIC,
                        USB_DEVICE_ID_PANABOARD_UBT880) },

        /* PixArt optical touch screen */
        { .driver_data = MT_CLS_INRANGE_CONTACTNUMBER,
                MT_USB_DEVICE(USB_VENDOR_ID_PIXART,
                        USB_DEVICE_ID_PIXART_OPTICAL_TOUCH_SCREEN) },
        { .driver_data = MT_CLS_INRANGE_CONTACTNUMBER,
                MT_USB_DEVICE(USB_VENDOR_ID_PIXART,
                        USB_DEVICE_ID_PIXART_OPTICAL_TOUCH_SCREEN1) },
        { .driver_data = MT_CLS_INRANGE_CONTACTNUMBER,
                MT_USB_DEVICE(USB_VENDOR_ID_PIXART,
                        USB_DEVICE_ID_PIXART_OPTICAL_TOUCH_SCREEN2) },

        /* PixCir-based panels */
        { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTID,
                MT_USB_DEVICE(USB_VENDOR_ID_CANDO,
                        USB_DEVICE_ID_CANDO_PIXCIR_MULTI_TOUCH) },

        /* Quanta-based panels */
        { .driver_data = MT_CLS_CONFIDENCE_CONTACT_ID,
                MT_USB_DEVICE(USB_VENDOR_ID_QUANTA,
                        USB_DEVICE_ID_QUANTA_OPTICAL_TOUCH_3001) },

        /* Razer touchpads */
        { .driver_data = MT_CLS_RAZER_BLADE_STEALTH,
                HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
                        USB_VENDOR_ID_SYNAPTICS, 0x8323) },

        /* Smart Tech panels */
        { .driver_data = MT_CLS_SMART_TECH,
                MT_USB_DEVICE(0x0b8c, 0x0092)},

        /* Stantum panels */
        { .driver_data = MT_CLS_CONFIDENCE,
                MT_USB_DEVICE(USB_VENDOR_ID_STANTUM_STM,
                        USB_DEVICE_ID_MTP_STM)},

        /* Synaptics devices */
        { .driver_data = MT_CLS_WIN_8_FORCE_MULTI_INPUT,
                HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
                        USB_VENDOR_ID_SYNAPTICS, 0xce08) },

        { .driver_data = MT_CLS_WIN_8_FORCE_MULTI_INPUT,
                HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
                        USB_VENDOR_ID_SYNAPTICS, 0xce09) },

        /* TopSeed panels */
        { .driver_data = MT_CLS_TOPSEED,
                MT_USB_DEVICE(USB_VENDOR_ID_TOPSEED2,
                        USB_DEVICE_ID_TOPSEED2_PERIPAD_701) },

        /* Touch International panels */
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_TOUCH_INTL,
                        USB_DEVICE_ID_TOUCH_INTL_MULTI_TOUCH) },

        /* Unitec panels */
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_UNITEC,
                        USB_DEVICE_ID_UNITEC_USB_TOUCH_0709) },
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_UNITEC,
                        USB_DEVICE_ID_UNITEC_USB_TOUCH_0A19) },

        /* VTL panels */
        { .driver_data = MT_CLS_VTL,
                MT_USB_DEVICE(USB_VENDOR_ID_VTL,
                        USB_DEVICE_ID_VTL_MULTITOUCH_FF3F) },

        /* Wistron panels */
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_WISTRON,
                        USB_DEVICE_ID_WISTRON_OPTICAL_TOUCH) },

        /* XAT */
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_XAT,
                        USB_DEVICE_ID_XAT_CSR) },

        /* Xiroku */
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_XIROKU,
                        USB_DEVICE_ID_XIROKU_SPX) },
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_XIROKU,
                        USB_DEVICE_ID_XIROKU_MPX) },
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_XIROKU,
                        USB_DEVICE_ID_XIROKU_CSR) },
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_XIROKU,
                        USB_DEVICE_ID_XIROKU_SPX1) },
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_XIROKU,
                        USB_DEVICE_ID_XIROKU_MPX1) },
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_XIROKU,
                        USB_DEVICE_ID_XIROKU_CSR1) },
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_XIROKU,
                        USB_DEVICE_ID_XIROKU_SPX2) },
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_XIROKU,
                        USB_DEVICE_ID_XIROKU_MPX2) },
        { .driver_data = MT_CLS_NSMU,
                MT_USB_DEVICE(USB_VENDOR_ID_XIROKU,
                        USB_DEVICE_ID_XIROKU_CSR2) },

        /* Google MT devices */
        { .driver_data = MT_CLS_GOOGLE,
                HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, USB_VENDOR_ID_GOOGLE,
                        USB_DEVICE_ID_GOOGLE_TOUCH_ROSE) },

        /* Generic MT device */
        { HID_DEVICE(HID_BUS_ANY, HID_GROUP_MULTITOUCH, HID_ANY_ID, HID_ANY_ID) },

        /* Generic Win 8 certified MT device */
        {  .driver_data = MT_CLS_WIN_8,
                HID_DEVICE(HID_BUS_ANY, HID_GROUP_MULTITOUCH_WIN_8,
                        HID_ANY_ID, HID_ANY_ID) },
        { }
};
MODULE_DEVICE_TABLE(hid, mt_devices);

static const struct hid_usage_id mt_grabbed_usages[] = {
        { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
        { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
};

static struct hid_driver mt_driver = {
        .name = "hid-multitouch",
        .id_table = mt_devices,
        .probe = mt_probe,
        .remove = mt_remove,
        .input_mapping = mt_input_mapping,
        .input_mapped = mt_input_mapped,
        .input_configured = mt_input_configured,
        .feature_mapping = mt_feature_mapping,
        .usage_table = mt_grabbed_usages,
        .event = mt_event,
        .report = mt_report,
#ifdef CONFIG_PM
        .suspend = mt_suspend,
        .reset_resume = mt_reset_resume,
        .resume = mt_resume,
#endif
};
module_hid_driver(mt_driver);