/*
   *  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 program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the Free
   * Software Foundation; either version 2 of the License, or (at your option)
   * any later version.
   */

  /*
   * This driver is regularly tested thanks to the tool hid-test[1].
   * This tool relies on hid-replay[2] and a database of hid devices[3].
   * Please run these regression tests before patching this module so that
   * your patch won't break existing known devices.
   *
   * [1] https://github.com/bentiss/hid-test
   * [2] https://github.com/bentiss/hid-replay
   * [3] https://github.com/bentiss/hid-devices
   */

  #include <linux/device.h>
  #include <linux/hid.h>
  #include <linux/module.h>
  #include <linux/slab.h>

  #include <linux/input/mt.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_INPUTMODE_TOUCHSCREEN	0x02
  #define MT_INPUTMODE_TOUCHPAD		0x03

  #define MT_BUTTONTYPE_CLICKPAD		0

  #define MT_IO_FLAGS_RUNNING		0

  #define MT_IO_FLAGS_ACTIVE_SLOTS	1
  #define MT_IO_FLAGS_PENDING_SLOTS	2

  struct mt_slot {

  	__s32 x, y, cx, cy, p, w, h;

  	__s32 contactid;	/* the device ContactID assigned to this slot */
  	bool touch_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_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_fields {
  	unsigned usages[HID_MAX_FIELDS];
  	unsigned int length;
  };

  struct mt_device {
  	struct mt_slot curdata;	/* placeholder of incoming data */

  	struct mt_class mtclass;	/* our mt device class */

  	struct timer_list release_timer;	/* to release sticky fingers */

  	struct mt_fields *fields;	/* temporary placeholder for storing the
  					   multitouch fields */

  	unsigned long mt_io_flags;	/* mt flags (MT_IO_FLAGS_*) */

  	int cc_index;	/* contact count field index in the report */
  	int cc_value_index;	/* contact count value index in the field */

  	unsigned last_slot_field;	/* the last field of a slot */

  	unsigned mt_report_id;	/* the report ID of the multitouch device */

  	unsigned long initial_quirks;	/* initial quirks state */

  	__s16 inputmode;	/* InputMode HID feature, -1 if non-existent */
  	__s16 inputmode_index;	/* InputMode HID feature index in the report */
  	__s16 maxcontact_report_id;	/* Maximum Contact Number HID feature,

  				   -1 if non-existent */

  	__u8 inputmode_value;  /* InputMode HID feature value */

  	__u8 num_received;	/* how many contacts we received */
  	__u8 num_expected;	/* expected last contact index */

  	__u8 maxcontacts;

  	__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 */

  	__u8 buttons_count;	/* number of physical buttons per touchpad */

  	bool is_buttonpad;	/* is this device a button pad? */

  	bool serial_maybe;	/* need to check for serial protocol */

  	bool curvalid;		/* is the current contact valid? */

  	unsigned mt_flags;	/* flags to pass to input-mt */

  };

  static void mt_post_parse_default_settings(struct mt_device *td);
  static void mt_post_parse(struct mt_device *td);

  /* 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

  #define MT_CLS_WIN_8_DUAL			0x0014

  
  /* 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_DEFAULT_MAXCONTACT	10

  #define MT_MAX_MAXCONTACT	250

  #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_device *td)
  {
  	if (td->curdata.contactid != 0 || td->num_received == 0)
  		return td->curdata.contactid;
  	else
  		return -1;
  }

  static 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 },

  	{ .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_DUAL,
  		.quirks = MT_QUIRK_ALWAYS_VALID |
  			MT_QUIRK_IGNORE_DUPLICATES |
  			MT_QUIRK_HOVERING |
  			MT_QUIRK_CONTACT_CNT_ACCURATE,
  		.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
  	},

  	{ }

  };

  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
  ", 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);
  
  	unsigned long val;
  
  	if (kstrtoul(buf, 0, &val))
  		return -EINVAL;
  
  	td->mtclass.quirks = val;

  	if (td->cc_index < 0)

  		td->mtclass.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)
  {
  	struct mt_device *td = hid_get_drvdata(hdev);

  	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 (td->initial_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
  ",
  			 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
  ");
  	}
  
  	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_INPUTMODE:

  		/* Ignore if value index is out of bounds. */
  		if (usage->usage_index >= field->report_count) {
  			dev_err(&hdev->dev, "HID_DG_INPUTMODE out of range
  ");
  			break;

  		}

  		if (td->inputmode < 0) {
  			td->inputmode = field->report->id;
  			td->inputmode_index = usage->usage_index;
  		} else {
  			/*
  			 * 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.
  			 */
  			dev_info(&hdev->dev,
  				 "Ignoring the extra HID_DG_INPUTMODE
  ");
  		}

  		break;
  	case HID_DG_CONTACTMAX:

  		mt_get_feature(hdev, field->report);

  		td->maxcontact_report_id = field->report->id;

  		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
  ");
  			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 void mt_store_field(struct hid_usage *usage, struct mt_device *td,

  		struct hid_input *hi)
  {

  	struct mt_fields *f = td->fields;
  
  	if (f->length >= HID_MAX_FIELDS)
  		return;
  
  	f->usages[f->length++] = usage->hid;

  }

  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_device *td = hid_get_drvdata(hdev);

  	struct mt_class *cls = &td->mtclass;

  	int code;

  	struct hid_usage *prev_usage = NULL;

  	if (field->application == HID_DG_TOUCHSCREEN)

  		td->mt_flags |= INPUT_MT_DIRECT;

  	/*
  	 * Model touchscreens providing buttons as touchpads.

  	 */
  	if (field->application == HID_DG_TOUCHPAD ||

  	    (usage->hid & HID_USAGE_PAGE) == HID_UP_BUTTON) {

  		td->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)
  		td->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)) {
  				hid_map_usage(hi, usage, bit, max,
  					EV_ABS, ABS_MT_TOOL_X);
  				set_abs(hi->input, ABS_MT_TOOL_X, field,
  					cls->sn_move);
  			} else {
  				hid_map_usage(hi, usage, bit, max,

  					EV_ABS, ABS_MT_POSITION_X);

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

  			mt_store_field(usage, td, hi);

  			return 1;
  		case HID_GD_Y:

  			if (prev_usage && (prev_usage->hid == usage->hid)) {
  				hid_map_usage(hi, usage, bit, max,
  					EV_ABS, ABS_MT_TOOL_Y);
  				set_abs(hi->input, ABS_MT_TOOL_Y, field,
  					cls->sn_move);
  			} else {
  				hid_map_usage(hi, usage, bit, max,

  					EV_ABS, ABS_MT_POSITION_Y);

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

  			mt_store_field(usage, td, hi);

  			return 1;
  		}
  		return 0;
  
  	case HID_UP_DIGITIZER:
  		switch (usage->hid) {
  		case HID_DG_INRANGE:

  			if (cls->quirks & MT_QUIRK_HOVERING) {
  				hid_map_usage(hi, usage, bit, max,
  					EV_ABS, ABS_MT_DISTANCE);
  				input_set_abs_params(hi->input,
  					ABS_MT_DISTANCE, 0, 1, 0, 0);
  			}

  			mt_store_field(usage, td, hi);

  			return 1;
  		case HID_DG_CONFIDENCE:

  			if ((cls->name == MT_CLS_WIN_8 ||
  				cls->name == MT_CLS_WIN_8_DUAL) &&

  				field->application == HID_DG_TOUCHPAD)
  				cls->quirks |= MT_QUIRK_CONFIDENCE;

  			mt_store_field(usage, td, hi);

  			return 1;
  		case HID_DG_TIPSWITCH:
  			hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
  			input_set_capability(hi->input, EV_KEY, BTN_TOUCH);

  			mt_store_field(usage, td, hi);

  			return 1;
  		case HID_DG_CONTACTID:

  			mt_store_field(usage, td, hi);

  			td->touches_by_report++;

  			td->mt_report_id = field->report->id;

  			return 1;
  		case HID_DG_WIDTH:
  			hid_map_usage(hi, usage, bit, max,
  					EV_ABS, ABS_MT_TOUCH_MAJOR);

  			if (!(cls->quirks & MT_QUIRK_NO_AREA))
  				set_abs(hi->input, ABS_MT_TOUCH_MAJOR, field,
  					cls->sn_width);

  			mt_store_field(usage, td, hi);

  			return 1;
  		case HID_DG_HEIGHT:
  			hid_map_usage(hi, usage, bit, max,
  					EV_ABS, ABS_MT_TOUCH_MINOR);

  			if (!(cls->quirks & MT_QUIRK_NO_AREA)) {
  				set_abs(hi->input, ABS_MT_TOUCH_MINOR, field,
  					cls->sn_height);
  				input_set_abs_params(hi->input,

  					ABS_MT_ORIENTATION, 0, 1, 0, 0);

  			}

  			mt_store_field(usage, td, hi);

  			return 1;
  		case HID_DG_TIPPRESSURE:
  			hid_map_usage(hi, usage, bit, max,
  					EV_ABS, ABS_MT_PRESSURE);
  			set_abs(hi->input, ABS_MT_PRESSURE, field,
  				cls->sn_pressure);

  			mt_store_field(usage, td, hi);

  			return 1;
  		case HID_DG_CONTACTCOUNT:

  			/* Ignore if indexes are out of bounds. */
  			if (field->index >= field->report->maxfield ||
  			    usage->usage_index >= field->report_count)
  				return 1;

  			td->cc_index = field->index;
  			td->cc_value_index = usage->usage_index;

  			return 1;
  		case HID_DG_CONTACTMAX:
  			/* we don't set td->last_slot_field as contactcount and
  			 * 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 ((cls->name == MT_CLS_WIN_8 ||
  			cls->name == MT_CLS_WIN_8_DUAL) &&

  		    field->application == HID_DG_TOUCHPAD &&
  		    (usage->hid & HID_USAGE) > 1)
  			code--;

  		hid_map_usage(hi, usage, bit, max, EV_KEY, code);
  		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 input_dev *input)

  {

  	__s32 quirks = td->mtclass.quirks;

  	if (quirks & MT_QUIRK_SLOT_IS_CONTACTID)
  		return td->curdata.contactid;

  	if (quirks & MT_QUIRK_CYPRESS)

  		return cypress_compute_slot(td);

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

  	if (quirks & MT_QUIRK_SLOT_IS_CONTACTID_MINUS_ONE)
  		return td->curdata.contactid - 1;

  	return input_mt_get_slot_by_key(input, td->curdata.contactid);

  }
  
  /*
   * this function is called when a whole contact has been processed,
   * so that it can assign it to a slot and store the data there
   */

  static void mt_complete_slot(struct mt_device *td, struct input_dev *input)

  {

  	if ((td->mtclass.quirks & MT_QUIRK_CONTACT_CNT_ACCURATE) &&
  	    td->num_received >= td->num_expected)
  		return;

  	if (td->curvalid || (td->mtclass.quirks & MT_QUIRK_ALWAYS_VALID)) {

  		int active;

  		int slotnum = mt_compute_slot(td, input);
  		struct mt_slot *s = &td->curdata;

  		struct input_mt *mt = input->mt;

  		if (slotnum < 0 || slotnum >= td->maxcontacts)
  			return;

  		if ((td->mtclass.quirks & MT_QUIRK_IGNORE_DUPLICATES) && mt) {
  			struct input_mt_slot *slot = &mt->slots[slotnum];
  			if (input_mt_is_active(slot) &&
  			    input_mt_is_used(mt, slot))
  				return;
  		}

  		if (!(td->mtclass.quirks & MT_QUIRK_CONFIDENCE))
  			s->confidence_state = 1;
  		active = (s->touch_state || s->inrange_state) &&
  							s->confidence_state;

  		input_mt_slot(input, slotnum);

  		input_mt_report_slot_state(input, MT_TOOL_FINGER, active);
  		if (active) {

  			/* this finger is in proximity of the sensor */

  			int wide = (s->w > s->h);

  			int major = max(s->w, s->h);
  			int minor = min(s->w, s->h);
  
  			/*
  			 * divided by two to match visual scale of touch
  			 * for devices with this quirk
  			 */
  			if (td->mtclass.quirks & MT_QUIRK_TOUCH_SIZE_SCALING) {
  				major = major >> 1;
  				minor = minor >> 1;
  			}

  			input_event(input, EV_ABS, ABS_MT_POSITION_X, s->x);
  			input_event(input, EV_ABS, ABS_MT_POSITION_Y, s->y);

  			input_event(input, EV_ABS, ABS_MT_TOOL_X, s->cx);
  			input_event(input, EV_ABS, ABS_MT_TOOL_Y, s->cy);

  			input_event(input, EV_ABS, ABS_MT_DISTANCE,
  				!s->touch_state);

  			input_event(input, EV_ABS, ABS_MT_ORIENTATION, wide);

  			input_event(input, EV_ABS, ABS_MT_PRESSURE, s->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);

  		}

  	}

  	td->num_received++;
  }
  
  /*
   * 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 input_dev *input)
  {

  	input_mt_sync_frame(input);

  	input_sync(input);
  	td->num_received = 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_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 void mt_process_mt_event(struct hid_device *hid, struct hid_field *field,

  				struct hid_usage *usage, __s32 value,
  				bool first_packet)

  {

  	struct mt_device *td = hid_get_drvdata(hid);

  	__s32 cls = td->mtclass.name;

  	__s32 quirks = td->mtclass.quirks;

  	struct input_dev *input = field->hidinput->input;

  	if (hid->claimed & HID_CLAIMED_INPUT) {

  		switch (usage->hid) {
  		case HID_DG_INRANGE:

  			if (quirks & MT_QUIRK_VALID_IS_INRANGE)

  				td->curvalid = value;

  			if (quirks & MT_QUIRK_HOVERING)
  				td->curdata.inrange_state = value;

  			break;
  		case HID_DG_TIPSWITCH:

  			if (quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
  				td->curvalid = value;

  			td->curdata.touch_state = value;
  			break;
  		case HID_DG_CONFIDENCE:

  			if (quirks & MT_QUIRK_CONFIDENCE)
  				td->curdata.confidence_state = value;

  			if (quirks & MT_QUIRK_VALID_IS_CONFIDENCE)
  				td->curvalid = value;

  			break;
  		case HID_DG_CONTACTID:
  			td->curdata.contactid = value;
  			break;
  		case HID_DG_TIPPRESSURE:
  			td->curdata.p = value;
  			break;
  		case HID_GD_X:

  			if (usage->code == ABS_MT_TOOL_X)
  				td->curdata.cx = value;
  			else
  				td->curdata.x = value;

  			break;
  		case HID_GD_Y:

  			if (usage->code == ABS_MT_TOOL_Y)
  				td->curdata.cy = value;
  			else
  				td->curdata.y = value;

  			break;
  		case HID_DG_WIDTH:
  			td->curdata.w = value;
  			break;
  		case HID_DG_HEIGHT:
  			td->curdata.h = value;
  			break;
  		case HID_DG_CONTACTCOUNT:

  			break;

  		case HID_DG_TOUCH:
  			/* do nothing */
  			break;

  
  		default:

  			/*
  			 * For Win8 PTP touchpads we should only look at
  			 * non finger/touch events in the first_packet of
  			 * a (possible) multi-packet frame.
  			 */
  			if ((cls == MT_CLS_WIN_8 || cls == MT_CLS_WIN_8_DUAL) &&
  			    !first_packet)
  				return;

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

  			return;

  		}

  		if (usage->usage_index + 1 == field->report_count) {
  			/* we only take into account the last report. */
  			if (usage->hid == td->last_slot_field)
  				mt_complete_slot(td, field->hidinput->input);

  		}

  	}

  }

  static void mt_touch_report(struct hid_device *hid, struct hid_report *report)

  {
  	struct mt_device *td = hid_get_drvdata(hid);
  	struct hid_field *field;

  	bool first_packet;

  	unsigned count;
  	int r, n;

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

  	/*
  	 * Includes multi-packet support where subsequent
  	 * packets are sent with zero contactcount.
  	 */

  	if (td->cc_index >= 0) {
  		struct hid_field *field = report->field[td->cc_index];
  		int value = field->value[td->cc_value_index];
  		if (value)
  			td->num_expected = value;
  	}

  	first_packet = td->num_received == 0;

  	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, field, &field->usage[n],

  					    field->value[n], first_packet);

  	}

  
  	if (td->num_received >= td->num_expected)
  		mt_sync_frame(td, report->field[0]->hidinput->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 (td->mtclass.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_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);
  	if (td->serial_maybe)
  		mt_post_parse_default_settings(td);
  
  	if (cls->is_indirect)
  		td->mt_flags |= INPUT_MT_POINTER;
  
  	if (cls->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
  		td->mt_flags |= INPUT_MT_DROP_UNUSED;

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

  		td->is_buttonpad = true;
  
  	if (td->is_buttonpad)

  		__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);

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

  
  	td->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);
  
  	/*
  	 * 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_VD_ASUS_CUSTOM_MEDIA_KEYS &&
  	      td->mtclass.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 &&

  	    td->mtclass.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;
  	}
  
  	/*

  	 * some egalax touchscreens have "application == HID_DG_TOUCHSCREEN"
  	 * for the stylus.

  	 * The check for mt_report_id ensures we don't process
  	 * HID_DG_CONTACTCOUNT from the pen report as it is outside the physical
  	 * collection, but within the report ID.

  	 */

  	if (field->physical == HID_DG_STYLUS)

  		return 0;

  	else if ((field->physical == 0) &&
  		 (field->report->id != td->mt_report_id) &&
  		 (td->mt_report_id != -1))
  		return 0;

  	if (field->application == HID_DG_TOUCHSCREEN ||
  	    field->application == HID_DG_TOUCHPAD)
  		return mt_touch_input_mapping(hdev, hi, field, usage, bit, max);
  
  	/* 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)
  {

  	/*
  	 * some egalax touchscreens have "application == HID_DG_TOUCHSCREEN"
  	 * for the stylus.
  	 */

  	if (field->physical == HID_DG_STYLUS)

  		return 0;

  	if (field->application == HID_DG_TOUCHSCREEN ||

  	    field->application == HID_DG_TOUCHPAD) {
  		/* 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);
  
  	if (field->report->id == td->mt_report_id)
  		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];

  
  	if (!(hid->claimed & HID_CLAIMED_INPUT))
  		return;
  
  	if (report->id == td->mt_report_id)

  		return mt_touch_report(hid, report);

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

  }
  
  static void mt_set_input_mode(struct hid_device *hdev)
  {
  	struct mt_device *td = hid_get_drvdata(hdev);
  	struct hid_report *r;
  	struct hid_report_enum *re;

  	struct mt_class *cls = &td->mtclass;
  	char *buf;

  	u32 report_len;

  
  	if (td->inputmode < 0)
  		return;
  
  	re = &(hdev->report_enum[HID_FEATURE_REPORT]);
  	r = re->report_id_hash[td->inputmode];
  	if (r) {

  		if (cls->quirks & MT_QUIRK_FORCE_GET_FEATURE) {

  			report_len = hid_report_len(r);

  			buf = hid_alloc_report_buf(r, GFP_KERNEL);
  			if (!buf) {
  				hid_err(hdev, "failed to allocate buffer for report
  ");
  				return;
  			}
  			hid_hw_raw_request(hdev, r->id, buf, report_len,
  					   HID_FEATURE_REPORT,
  					   HID_REQ_GET_REPORT);
  			kfree(buf);
  		}

  		r->field[0]->value[td->inputmode_index] = td->inputmode_value;

  		hid_hw_request(hdev, r, HID_REQ_SET_REPORT);

  	}
  }

  static void mt_set_maxcontacts(struct hid_device *hdev)
  {
  	struct mt_device *td = hid_get_drvdata(hdev);
  	struct hid_report *r;
  	struct hid_report_enum *re;
  	int fieldmax, max;
  
  	if (td->maxcontact_report_id < 0)
  		return;
  
  	if (!td->mtclass.maxcontacts)
  		return;
  
  	re = &hdev->report_enum[HID_FEATURE_REPORT];
  	r = re->report_id_hash[td->maxcontact_report_id];
  	if (r) {
  		max = td->mtclass.maxcontacts;
  		fieldmax = r->field[0]->logical_maximum;
  		max = min(fieldmax, max);
  		if (r->field[0]->value[0] != max) {
  			r->field[0]->value[0] = max;

  			hid_hw_request(hdev, r, HID_REQ_SET_REPORT);

  		}
  	}
  }

  static void mt_post_parse_default_settings(struct mt_device *td)
  {
  	__s32 quirks = td->mtclass.quirks;
  
  	/* unknown serial device needs special quirks */
  	if (td->touches_by_report == 1) {
  		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;

  	}
  
  	td->mtclass.quirks = quirks;
  }

  static void mt_post_parse(struct mt_device *td)
  {
  	struct mt_fields *f = td->fields;

  	struct mt_class *cls = &td->mtclass;

  
  	if (td->touches_by_report > 0) {
  		int field_count_per_touch = f->length / td->touches_by_report;
  		td->last_slot_field = f->usages[field_count_per_touch - 1];
  	}

  	if (td->cc_index < 0)

  		cls->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 hid_field *field = hi->report->field[0];

  	int ret;

  	if (hi->report->id == td->mt_report_id) {
  		ret = mt_touch_input_configured(hdev, hi);
  		if (ret)
  			return ret;
  	}

  	/*
  	 * some egalax touchscreens have "application == HID_DG_TOUCHSCREEN"
  	 * for the stylus. Check this first, and then rely on the application
  	 * field.
  	 */

  	if (hi->report->field[0]->physical == HID_DG_STYLUS) {
  		suffix = "Pen";

  		/* force BTN_STYLUS to allow tablet matching in udev */
  		__set_bit(BTN_STYLUS, hi->input->keybit);

  	} else {
  		switch (field->application) {
  		case HID_GD_KEYBOARD:
  			suffix = "Keyboard";
  			break;
  		case HID_GD_KEYPAD:
  			suffix = "Keypad";
  			break;
  		case HID_GD_MOUSE:
  			suffix = "Mouse";
  			break;
  		case HID_DG_STYLUS:
  			suffix = "Pen";
  			/* force BTN_STYLUS to allow tablet matching in udev */
  			__set_bit(BTN_STYLUS, hi->input->keybit);
  			break;
  		case HID_DG_TOUCHSCREEN:
  			/* we do not set suffix = "Touchscreen" */
  			break;

  		case HID_DG_TOUCHPAD:
  			suffix = "Touchpad";
  			break;

  		case HID_GD_SYSTEM_CONTROL:
  			suffix = "System Control";
  			break;
  		case HID_CP_CONSUMER_CONTROL:
  			suffix = "Consumer Control";
  			break;

  		case HID_GD_WIRELESS_RADIO_CTLS:
  			suffix = "Wireless Radio Control";
  			break;

  		case HID_VD_ASUS_CUSTOM_MEDIA_KEYS:
  			suffix = "Custom Media Keys";
  			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_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_state(input_dev,
  							   MT_TOOL_FINGER,
  							   false);
  			}
  			input_mt_sync_frame(input_dev);
  			input_sync(input_dev);
  		}
  	}
  
  	td->num_received = 0;
  }
  
  static void mt_expired_timeout(unsigned long arg)
  {
  	struct hid_device *hdev = (void *)arg;
  	struct mt_device *td = hid_get_drvdata(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;

  	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
  ");
  		return -ENOMEM;
  	}

  	td->mtclass = *mtclass;

  	td->inputmode = -1;

  	td->maxcontact_report_id = -1;

  	td->inputmode_value = MT_INPUTMODE_TOUCHSCREEN;

  	td->cc_index = -1;

  	td->mt_report_id = -1;

  	hid_set_drvdata(hdev, td);

  	td->fields = devm_kzalloc(&hdev->dev, sizeof(struct mt_fields),
  				  GFP_KERNEL);

  	if (!td->fields) {
  		dev_err(&hdev->dev, "cannot allocate multitouch fields data
  ");

  		return -ENOMEM;

  	}

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

  	/*
  	 * Store the initial quirk state
  	 */
  	td->initial_quirks = hdev->quirks;
  
  	/* 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 reports on the same HID
  	 * device.
  	 */
  	hdev->quirks |= HID_QUIRK_MULTI_INPUT;
  	hdev->quirks |= HID_QUIRK_NO_EMPTY_INPUT;
  
  	/*
  	 * Some multitouch screens do not like to be polled for input
  	 * reports. Fortunately, the Win8 spec says that all touches
  	 * should be sent during each report, making the initialization
  	 * of input reports unnecessary. For Win7 devices, well, let's hope
  	 * they will still be happy (this is only be a problem if a touch
  	 * was already there while probing the device).
  	 *
  	 * In addition some touchpads do not behave well if we read
  	 * all feature reports from them. Instead we prevent
  	 * initial report fetching and then selectively fetch each
  	 * report we are interested in.
  	 */
  	hdev->quirks |= HID_QUIRK_NO_INIT_REPORTS;

  	setup_timer(&td->release_timer, mt_expired_timeout, (long)hdev);

  	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
  ",
  				hdev->name);

  	mt_set_maxcontacts(hdev);

  	mt_set_input_mode(hdev);

  	/* release .fields memory as it is not used anymore */
  	devm_kfree(&hdev->dev, td->fields);

  	td->fields = NULL;

  	return 0;

  }
  
  #ifdef CONFIG_PM
  static int mt_reset_resume(struct hid_device *hdev)
  {

  	mt_release_contacts(hdev);

  	mt_set_maxcontacts(hdev);

  	mt_set_input_mode(hdev);
  	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);

  
  	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);

  	hdev->quirks = td->initial_quirks;

  }

  /*
   * 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) },

  	/* Alps devices */
  	{ .driver_data = MT_CLS_WIN_8_DUAL,
  		HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
  			USB_VENDOR_ID_ALPS_JP,
  			HID_DEVICE_ID_ALPS_U1_DUAL_PTP) },
  	{ .driver_data = MT_CLS_WIN_8_DUAL,
  		HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
  			USB_VENDOR_ID_ALPS_JP,
  			HID_DEVICE_ID_ALPS_U1_DUAL_3BTN_PTP) },

  	/* Lenovo X1 TAB Gen 2 */
  	{ .driver_data = MT_CLS_WIN_8_DUAL,
  		HID_DEVICE(BUS_USB, HID_GROUP_MULTITOUCH_WIN_8,
  			   USB_VENDOR_ID_LENOVO,
  			   USB_DEVICE_ID_LENOVO_X1_TAB) },

  	/* 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) },

  	/* Cirque devices */
  	{ .driver_data = MT_CLS_WIN_8_DUAL,
  		HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
  			I2C_VENDOR_ID_CIRQUE,
  			I2C_PRODUCT_ID_CIRQUE_121F) },

  	/* 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) },

  	/* 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) },

  	/* 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) },

  	/* 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) },

  	/* 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) },

  	/* 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) },

  	/* Stantum panels */

  	{ .driver_data = MT_CLS_CONFIDENCE,

  		MT_USB_DEVICE(USB_VENDOR_ID_STANTUM_STM,

  			USB_DEVICE_ID_MTP_STM)},

  	/* 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,