/*
 * Copyright © 1999 Henry Davies
 * Copyright © 2001 Stefan Gmeiner
 * Copyright © 2002 S. Lehner
 * Copyright © 2002 Peter Osterlund
 * Copyright © 2002 Linuxcare Inc. David Kennedy
 * Copyright © 2003 Hartwig Felger
 * Copyright © 2003 Jörg Bösner
 * Copyright © 2003 Fred Hucht
 * Copyright © 2004 Alexei Gilchrist
 * Copyright © 2004 Matthias Ihmig
 * Copyright © 2006 Stefan Bethge
 * Copyright © 2006 Christian Thaeter
 * Copyright © 2007 Joseph P. Skudlarek
 * Copyright © 2008 Fedor P. Goncharov
 * Copyright © 2008-2012 Red Hat, Inc.
 * Copyright © 2011 The Chromium OS Authors
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without
 * fee, provided that the above copyright notice appear in all copies
 * and that both that copyright notice and this permission notice
 * appear in supporting documentation, and that the name of Red Hat
 * not be used in advertising or publicity pertaining to distribution
 * of the software without specific, written prior permission.  Red
 * Hat makes no representations about the suitability of this software
 * for any purpose.  It is provided "as is" without express or implied
 * warranty.
 *
 * THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
 * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Authors:
 *      Joseph P. Skudlarek <Jskud@Jskud.com>
 *      Christian Thaeter <chth@gmx.net>
 *      Stefan Bethge <stefan.bethge@web.de>
 *      Matthias Ihmig <m.ihmig@gmx.net>
 *      Alexei Gilchrist <alexei@physics.uq.edu.au>
 *      Jörg Bösner <ich@joerg-boesner.de>
 *      Hartwig Felger <hgfelger@hgfelger.de>
 *      Peter Osterlund <petero2@telia.com>
 *      S. Lehner <sam_x@bluemail.ch>
 *      Stefan Gmeiner <riddlebox@freesurf.ch>
 *      Henry Davies <hdavies@ameritech.net> for the
 *      Linuxcare Inc. David Kennedy <dkennedy@linuxcare.com>
 *      Fred Hucht <fred@thp.Uni-Duisburg.de>
 *      Fedor P. Goncharov <fedgo@gorodok.net>
 *      Simon Thum <simon.thum@gmx.de>
 *
 * Trademarks are the property of their respective owners.
 */
#include "config.h"

#include <xorg-server.h>
#include <unistd.h>
#include <misc.h>
#include <xf86.h>
#include <math.h>
#include <stdio.h>
#include <xf86_OSproc.h>
#include <xf86Xinput.h>
#include <exevents.h>

#include <X11/Xatom.h>
#include <X11/extensions/XI2.h>
#include <xserver-properties.h>
#include <ptrveloc.h>

#include "synapticsstr.h"
#include "synaptics-properties.h"

enum EdgeType {
    NO_EDGE = 0,
    BOTTOM_EDGE = 1,
    TOP_EDGE = 2,
    LEFT_EDGE = 4,
    RIGHT_EDGE = 8,
    LEFT_BOTTOM_EDGE = BOTTOM_EDGE | LEFT_EDGE,
    RIGHT_BOTTOM_EDGE = BOTTOM_EDGE | RIGHT_EDGE,
    RIGHT_TOP_EDGE = TOP_EDGE | RIGHT_EDGE,
    LEFT_TOP_EDGE = TOP_EDGE | LEFT_EDGE
};

/*
 * We expect to be receiving a steady 80 packets/sec (which gives 40
 * reports/sec with more than one finger on the pad, as Advanced Gesture Mode
 * requires two PS/2 packets per report).  Instead of a random scattering of
 * magic 13 and 20ms numbers scattered throughout the driver, introduce
 * POLL_MS as 14ms, which is slightly less than 80Hz.  13ms is closer to
 * 80Hz, but if the kernel event reporting was even slightly delayed,
 * we would produce synthetic motion followed immediately by genuine
 * motion, so use 14.
 *
 * We use this to call back at a constant rate to at least produce the
 * illusion of smooth motion.  It works a lot better than you'd expect.
*/
#define POLL_MS 14

#define MAX(a, b) (((a)>(b))?(a):(b))
#define MIN(a, b) (((a)<(b))?(a):(b))
#define TIME_DIFF(a, b) ((int)((a)-(b)))

#define SQR(x) ((x) * (x))

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

#define INPUT_BUFFER_SIZE 200

/*****************************************************************************
 * Forward declaration
 ****************************************************************************/
static int SynapticsPreInit(InputDriverPtr drv, InputInfoPtr pInfo, int flags);
static void SynapticsUnInit(InputDriverPtr drv, InputInfoPtr pInfo, int flags);
static Bool DeviceControl(DeviceIntPtr, int);
static void ReadInput(InputInfoPtr);
static int HandleState(InputInfoPtr, struct SynapticsHwState *, CARD32 now,
                       Bool from_timer);
static int ControlProc(InputInfoPtr, xDeviceCtl *);
static int SwitchMode(ClientPtr, DeviceIntPtr, int);
static int DeviceInit(DeviceIntPtr);
static int DeviceOn(DeviceIntPtr);
static int DeviceOff(DeviceIntPtr);
static int DeviceClose(DeviceIntPtr);
static Bool QueryHardware(InputInfoPtr);
static void ReadDevDimensions(InputInfoPtr);
static void SanitizeDimensions(InputInfoPtr pInfo);

static const struct {
    const char *name;
    struct SynapticsProtocolOperations *proto_ops;
} protocols[] = {
#ifdef BUILD_EVENTCOMM
    { "event", &event_proto_operations },
#endif
#ifdef BUILD_PSMCOMM
    { "psm", &psm_proto_operations },
#endif
#ifdef BUILD_PS2COMM
    { "psaux", &psaux_proto_operations },
    { "alps", &alps_proto_operations },
#endif
    { NULL, NULL }
};

InputDriverRec SYNAPTICS = {
    1,
    "synaptics",
    NULL,
    SynapticsPreInit,
    SynapticsUnInit,
    NULL,
    NULL,
#ifdef XI86_DRV_CAP_SERVER_FD
    XI86_DRV_CAP_SERVER_FD
#endif
};

static XF86ModuleVersionInfo VersionRec = {
    "synaptics",
    MODULEVENDORSTRING,
    MODINFOSTRING1,
    MODINFOSTRING2,
    XORG_VERSION_CURRENT,
    PACKAGE_VERSION_MAJOR, PACKAGE_VERSION_MINOR, PACKAGE_VERSION_PATCHLEVEL,
    ABI_CLASS_XINPUT,
    ABI_XINPUT_VERSION,
    MOD_CLASS_XINPUT,
    {0, 0, 0, 0}
};

static pointer
SetupProc(pointer module, pointer options, int *errmaj, int *errmin)
{
    xf86AddInputDriver(&SYNAPTICS, module, 0);
    return module;
}

_X_EXPORT XF86ModuleData synapticsModuleData = {
    &VersionRec,
    &SetupProc,
    NULL
};

/*****************************************************************************
 *	Function Definitions
 ****************************************************************************/
static inline void
SynapticsCloseFd(InputInfoPtr pInfo)
{
    if (pInfo->fd > -1 && !(pInfo->flags & XI86_SERVER_FD)) {
        xf86CloseSerial(pInfo->fd);
        pInfo->fd = -1;
    }
}

/**
 * Fill in default dimensions for backends that cannot query the hardware.
 * Eventually, we want the edges to be 1900/5400 for x, 1900/4000 for y.
 * These values are based so that calculate_edge_widths() will give us the
 * right values.
 *
 * The default values 1900, etc. come from the dawn of time, when men where
 * men, or possibly apes.
 */
static void
SanitizeDimensions(InputInfoPtr pInfo)
{
    SynapticsPrivate *priv = (SynapticsPrivate *) pInfo->private;

    if (priv->minx >= priv->maxx) {
        priv->minx = 1615;
        priv->maxx = 5685;
        priv->resx = 0;

        xf86IDrvMsg(pInfo, X_PROBED,
                    "invalid x-axis range.  defaulting to %d - %d\n",
                    priv->minx, priv->maxx);
    }

    if (priv->miny >= priv->maxy) {
        priv->miny = 1729;
        priv->maxy = 4171;
        priv->resy = 0;

        xf86IDrvMsg(pInfo, X_PROBED,
                    "invalid y-axis range.  defaulting to %d - %d\n",
                    priv->miny, priv->maxy);
    }

    if (priv->minp >= priv->maxp) {
        priv->minp = 0;
        priv->maxp = 255;

        xf86IDrvMsg(pInfo, X_PROBED,
                    "invalid pressure range.  defaulting to %d - %d\n",
                    priv->minp, priv->maxp);
    }

    if (priv->minw >= priv->maxw) {
        priv->minw = 0;
        priv->maxw = 15;

        xf86IDrvMsg(pInfo, X_PROBED,
                    "invalid finger width range.  defaulting to %d - %d\n",
                    priv->minw, priv->maxw);
    }
}

static Bool
SetDeviceAndProtocol(InputInfoPtr pInfo)
{
    SynapticsPrivate *priv = pInfo->private;
    char *proto, *device;
    int i;

    proto = xf86SetStrOption(pInfo->options, "Protocol", NULL);
    device = xf86SetStrOption(pInfo->options, "Device", NULL);

    /* If proto is auto-dev, unset and let the code do the rest */
    if (proto && !strcmp(proto, "auto-dev")) {
        free(proto);
        proto = NULL;
    }

    for (i = 0; protocols[i].name; i++) {
        if ((!device || !proto) &&
            protocols[i].proto_ops->AutoDevProbe &&
            protocols[i].proto_ops->AutoDevProbe(pInfo, device))
            break;
        else if (proto && !strcmp(proto, protocols[i].name))
            break;
    }
    free(proto);
    free(device);

    priv->proto_ops = protocols[i].proto_ops;

    return (priv->proto_ops != NULL);
}

static void
calculate_edge_widths(SynapticsPrivate * priv, int *l, int *r, int *t, int *b)
{
    int width, height;
    int ewidth, eheight;        /* edge width/height */

    width = abs(priv->maxx - priv->minx);
    height = abs(priv->maxy - priv->miny);

    if (priv->model == MODEL_SYNAPTICS) {
        ewidth = width * .07;
        eheight = height * .07;
    }
    else if (priv->model == MODEL_ALPS) {
        ewidth = width * .15;
        eheight = height * .15;
    }
    else if (priv->model == MODEL_APPLETOUCH ||
             priv->model == MODEL_UNIBODY_MACBOOK) {
        ewidth = width * .085;
        eheight = height * .085;
    }
    else {
        ewidth = width * .04;
        eheight = height * .054;
    }

    *l = priv->minx + ewidth;
    *r = priv->maxx - ewidth;
    *t = priv->miny + eheight;
    *b = priv->maxy - eheight;
}

static void
calculate_tap_hysteresis(SynapticsPrivate * priv, int range,
                         int *fingerLow, int *fingerHigh)
{
    switch (priv->model) {
    case MODEL_ELANTECH:
        /* All Elantech touchpads don't need the Z filtering to get the
         * number of fingers correctly. See Documentation/elantech.txt
         * in the kernel.
         */
        *fingerLow = priv->minp + 1;
        *fingerHigh = priv->minp + 1;
        break;
    case MODEL_UNIBODY_MACBOOK:
        *fingerLow = 70;
        *fingerHigh = 75;
        break;
    default:
        *fingerLow = priv->minp + range * (25.0 / 256);
        *fingerHigh = priv->minp + range * (30.0 / 256);
        break;
    }
}

/* Area options support both percent values and absolute values. This is
 * awkward. The xf86Set* calls will print to the log, but they'll
 * also print an error if we request a percent value but only have an
 * int. So - check first for percent, then call xf86Set* again to get
 * the log message.
 */
static int
set_percent_option(pointer options, const char *optname,
                   const int range, const int offset, const int default_value)
{
    int result;
    double percent = xf86CheckPercentOption(options, optname, -1);

    if (percent >= 0.0) {
        percent = xf86SetPercentOption(options, optname, -1);
        result = percent / 100.0 * range + offset;
    } else
        result = xf86SetIntOption(options, optname, default_value);

    return result;
}

Bool
SynapticsIsSoftButtonAreasValid(int *values)
{
    Bool right_disabled = FALSE;
    Bool middle_disabled = FALSE;

    enum {
        /* right button left, right, top, bottom */
        RBL = 0,
        RBR = 1,
        RBT = 2,
        RBB = 3,
        /* middle button left, right, top, bottom */
        MBL = 4,
        MBR = 5,
        MBT = 6,
        MBB = 7,
    };

    /* Check right button area */
    if ((((values[RBL] != 0) && (values[RBR] != 0)) && (values[RBL] > values[RBR])) ||
        (((values[RBT] != 0) && (values[RBB] != 0)) && (values[RBT] > values[RBB])))
        return FALSE;

    /* Check middle button area */
    if ((((values[MBL] != 0) && (values[MBR] != 0)) && (values[MBL] > values[MBR])) ||
        (((values[MBT] != 0) && (values[MBB] != 0)) && (values[MBT] > values[MBB])))
        return FALSE;

    if (values[RBL] == 0 && values[RBR] == 0 && values[RBT] == 0 && values[RBB] == 0)
        right_disabled = TRUE;

    if (values[MBL] == 0 && values[MBR] == 0 && values[MBT] == 0 && values[MBB] == 0)
        middle_disabled = TRUE;

    if (!right_disabled &&
        ((values[RBL] && values[RBL] == values[RBR]) ||
         (values[RBT] && values[RBT] == values[RBB])))
        return FALSE;

    if (!middle_disabled &&
        ((values[MBL] && values[MBL] == values[MBR]) ||
         (values[MBT] && values[MBT] == values[MBB])))
        return FALSE;

    /* Check for overlapping button areas */
    if (!right_disabled && !middle_disabled) {
        int right_left = values[RBL] ? values[RBL] : INT_MIN;
        int right_right = values[RBR] ? values[RBR] : INT_MAX;
        int right_top = values[RBT] ? values[RBT] : INT_MIN;
        int right_bottom = values[RBB] ? values[RBB] : INT_MAX;
        int middle_left = values[MBL] ? values[MBL] : INT_MIN;
        int middle_right = values[MBR] ? values[MBR] : INT_MAX;
        int middle_top = values[MBT] ? values[MBT] : INT_MIN;
        int middle_bottom = values[MBB] ? values[MBB] : INT_MAX;

        /* If areas overlap in the Y axis */
        if ((right_bottom <= middle_bottom && right_bottom >= middle_top) ||
            (right_top <= middle_bottom && right_top >= middle_top)) {
            /* Check for overlapping left edges */
            if ((right_left < middle_left && right_right > middle_left) ||
                (middle_left < right_left && middle_right > right_left))
                return FALSE;

            /* Check for overlapping right edges */
            if ((right_right > middle_right && right_left < middle_right) ||
                (middle_right > right_right && middle_left < right_right))
                return FALSE;
        }

        /* If areas overlap in the X axis */
        if ((right_left >= middle_left && right_left <= middle_right) ||
            (right_right >= middle_left && right_right <= middle_right)) {
            /* Check for overlapping top edges */
            if ((right_top < middle_top && right_bottom > middle_top) ||
                (middle_top < right_top && middle_bottom > right_top))
                return FALSE;

            /* Check for overlapping bottom edges */
            if ((right_bottom > middle_bottom && right_top < middle_bottom) ||
                (middle_bottom > right_bottom && middle_top < right_bottom))
                return FALSE;
        }
    }

    return TRUE;
}

static void
set_softbutton_areas_option(InputInfoPtr pInfo, const char *option_name, int offset)
{
    SynapticsPrivate *priv = pInfo->private;
    SynapticsParameters *pars = &priv->synpara;
    int values[8];
    int in_percent = 0;         /* bitmask for which ones are in % */
    char *option_string;
    char *next_num;
    char *end_str;
    int i;
    int width, height;

    if (!pars->clickpad)
        return;

    option_string = xf86SetStrOption(pInfo->options, option_name, NULL);
    if (!option_string)
        return;

    next_num = option_string;

    for (i = 0; i < 8 && *next_num != '\0'; i++) {
        long int value = strtol(next_num, &end_str, 0);

        if (value > INT_MAX || value < -INT_MAX)
            goto fail;

        values[i] = value;

        if (next_num != end_str) {
            if (*end_str == '%') {
                in_percent |= 1 << i;
                end_str++;
            }
            next_num = end_str;
        }
        else
            goto fail;
    }

    if (i < 8 || *next_num != '\0')
        goto fail;

    width = priv->maxx - priv->minx;
    height = priv->maxy - priv->miny;

    for (i = 0; in_percent && i < 8; i++) {
        int base, size;

        if ((in_percent & (1 << i)) == 0 || values[i] == 0)
            continue;

        size = ((i % 4) < 2) ? width : height;
        base = ((i % 4) < 2) ? priv->minx : priv->miny;
        values[i] = base + size * values[i] / 100.0;
    }

    if (!SynapticsIsSoftButtonAreasValid(values))
        goto fail;

    memcpy(pars->softbutton_areas[offset], values, 4 * sizeof(int));
    memcpy(pars->softbutton_areas[offset + 1], values + 4, 4 * sizeof(int));

    free(option_string);

    return;

 fail:
    xf86IDrvMsg(pInfo, X_ERROR,
                "invalid %s value '%s', keeping defaults\n",
                option_name, option_string);
    free(option_string);
}

static void
set_primary_softbutton_areas_option(InputInfoPtr pInfo)
{
    set_softbutton_areas_option(pInfo, "SoftButtonAreas", BOTTOM_BUTTON_AREA);
}

static void
set_secondary_softbutton_areas_option(InputInfoPtr pInfo)
{
    set_softbutton_areas_option(pInfo, "SecondarySoftButtonAreas", TOP_BUTTON_AREA);
}

static void
set_default_parameters(InputInfoPtr pInfo)
{
    SynapticsPrivate *priv = pInfo->private;    /* read-only */
    pointer opts = pInfo->options;      /* read-only */
    SynapticsParameters *pars = &priv->synpara; /* modified */

    int horizScrollDelta, vertScrollDelta;      /* pixels */
    int tapMove;                /* pixels */
    int l, r, t, b;             /* left, right, top, bottom */
    double accelFactor;         /* 1/pixels */
    int fingerLow, fingerHigh;  /* pressure */
    int emulateTwoFingerMinZ;   /* pressure */
    int emulateTwoFingerMinW;   /* width */
    int pressureMotionMinZ, pressureMotionMaxZ; /* pressure */
    int palmMinWidth, palmMinZ; /* pressure */
    int tapButton1, tapButton2, tapButton3;
    int clickFinger1, clickFinger2, clickFinger3;
    Bool vertEdgeScroll, horizEdgeScroll;
    Bool vertTwoFingerScroll, horizTwoFingerScroll;
    int horizResolution = 1;
    int vertResolution = 1;
    int width, height, diag, range;
    int horizHyst, vertHyst;
    int middle_button_timeout;
    int grab_event_device = 0;
    const char *source;

    /* The synaptics specs specify typical edge widths of 4% on x, and 5.4% on
     * y (page 7) [Synaptics TouchPad Interfacing Guide, 510-000080 - A
     * Second Edition, http://www.synaptics.com/support/dev_support.cfm, 8 Sep
     * 2008]. We use 7% for both instead for synaptics devices, and 15% for
     * ALPS models.
     * http://bugs.freedesktop.org/show_bug.cgi?id=21214
     *
     * If the range was autodetected, apply these edge widths to all four
     * sides.
     */

    width = abs(priv->maxx - priv->minx);
    height = abs(priv->maxy - priv->miny);
    diag = sqrt(width * width + height * height);

    calculate_edge_widths(priv, &l, &r, &t, &b);

    /* Again, based on typical x/y range and defaults */
    horizScrollDelta = diag * .020;
    vertScrollDelta = diag * .020;
    tapMove = diag * .044;
    accelFactor = 200.0 / diag; /* trial-and-error */

    /* hysteresis, assume >= 0 is a detected value (e.g. evdev fuzz) */
    horizHyst = pars->hyst_x >= 0 ? pars->hyst_x : diag * 0.005;
    vertHyst = pars->hyst_y >= 0 ? pars->hyst_y : diag * 0.005;

    range = priv->maxp - priv->minp + 1;

    calculate_tap_hysteresis(priv, range, &fingerLow, &fingerHigh);

    /* scaling based on defaults and a pressure of 256 */
    emulateTwoFingerMinZ = priv->minp + range * (282.0 / 256);
    pressureMotionMinZ = priv->minp + range * (30.0 / 256);
    pressureMotionMaxZ = priv->minp + range * (160.0 / 256);
    palmMinZ = priv->minp + range * (200.0 / 256);

    range = priv->maxw - priv->minw + 1;

    /* scaling based on defaults below and a tool width of 16 */
    palmMinWidth = priv->minw + range * (10.0 / 16);
    emulateTwoFingerMinW = priv->minw + range * (7.0 / 16);

    /* Enable tap if we don't have a phys left button */
    tapButton1 = priv->has_left ? 0 : 1;
    tapButton2 = priv->has_left ? 0 : 3;
    tapButton3 = priv->has_left ? 0 : 2;

    /* Enable multifinger-click if only have one physical button,
       otherwise clickFinger is always button 1. */
    clickFinger1 = 1;
    clickFinger2 = (priv->has_right || priv->has_middle) ? 1 : 3;
    clickFinger3 = (priv->has_right || priv->has_middle) ? 1 : 2;

    /* Enable vert edge scroll if we can't detect doubletap */
    vertEdgeScroll = priv->has_double ? FALSE : TRUE;
    horizEdgeScroll = FALSE;

    /* Enable twofinger scroll if we can detect doubletap */
    vertTwoFingerScroll = priv->has_double ? TRUE : FALSE;
    horizTwoFingerScroll = FALSE;

    /* Use resolution reported by hardware if available */
    if ((priv->resx > 0) && (priv->resy > 0)) {
        horizResolution = priv->resx;
        vertResolution = priv->resy;
    }

    /* set the parameters */
    pars->left_edge = xf86SetIntOption(opts, "LeftEdge", l);
    pars->right_edge = xf86SetIntOption(opts, "RightEdge", r);
    pars->top_edge = xf86SetIntOption(opts, "TopEdge", t);
    pars->bottom_edge = xf86SetIntOption(opts, "BottomEdge", b);

    pars->area_top_edge =
        set_percent_option(opts, "AreaTopEdge", height, priv->miny, 0);
    pars->area_bottom_edge =
        set_percent_option(opts, "AreaBottomEdge", height, priv->miny, 0);
    pars->area_left_edge =
        set_percent_option(opts, "AreaLeftEdge", width, priv->minx, 0);
    pars->area_right_edge =
        set_percent_option(opts, "AreaRightEdge", width, priv->minx, 0);

    pars->hyst_x =
        set_percent_option(opts, "HorizHysteresis", width, 0, horizHyst);
    pars->hyst_y =
        set_percent_option(opts, "VertHysteresis", height, 0, vertHyst);

    pars->finger_low = xf86SetIntOption(opts, "FingerLow", fingerLow);
    pars->finger_high = xf86SetIntOption(opts, "FingerHigh", fingerHigh);
    pars->tap_time = xf86SetIntOption(opts, "MaxTapTime", 180);
    pars->tap_move = xf86SetIntOption(opts, "MaxTapMove", tapMove);
    pars->tap_time_2 = xf86SetIntOption(opts, "MaxDoubleTapTime", 180);
    pars->click_time = xf86SetIntOption(opts, "ClickTime", 100);
    pars->clickpad = xf86SetBoolOption(opts, "ClickPad", pars->clickpad);       /* Probed */
    if (pars->clickpad)
        pars->has_secondary_buttons = xf86SetBoolOption(opts,
                                                        "HasSecondarySoftButtons",
                                                        pars->has_secondary_buttons);
    pars->clickpad_ignore_motion_time = 100; /* ms */
    /* middle mouse button emulation on a clickpad? nah, you're joking */
    middle_button_timeout = pars->clickpad ? 0 : 75;
    pars->emulate_mid_button_time =
        xf86SetIntOption(opts, "EmulateMidButtonTime", middle_button_timeout);
    pars->emulate_twofinger_z =
        xf86SetIntOption(opts, "EmulateTwoFingerMinZ", emulateTwoFingerMinZ);
    pars->emulate_twofinger_w =
        xf86SetIntOption(opts, "EmulateTwoFingerMinW", emulateTwoFingerMinW);
    pars->scroll_dist_vert =
        xf86SetIntOption(opts, "VertScrollDelta", vertScrollDelta);
    pars->scroll_dist_horiz =
        xf86SetIntOption(opts, "HorizScrollDelta", horizScrollDelta);
    pars->scroll_edge_vert =
        xf86SetBoolOption(opts, "VertEdgeScroll", vertEdgeScroll);
    pars->scroll_edge_horiz =
        xf86SetBoolOption(opts, "HorizEdgeScroll", horizEdgeScroll);
    pars->scroll_edge_corner = xf86SetBoolOption(opts, "CornerCoasting", FALSE);
    pars->scroll_twofinger_vert =
        xf86SetBoolOption(opts, "VertTwoFingerScroll", vertTwoFingerScroll);
    pars->scroll_twofinger_horiz =
        xf86SetBoolOption(opts, "HorizTwoFingerScroll", horizTwoFingerScroll);
    pars->touchpad_off = xf86SetIntOption(opts, "TouchpadOff", TOUCHPAD_ON);

    if (priv->has_scrollbuttons) {
        pars->updown_button_scrolling =
            xf86SetBoolOption(opts, "UpDownScrolling", TRUE);
        pars->leftright_button_scrolling =
            xf86SetBoolOption(opts, "LeftRightScrolling", TRUE);
        pars->updown_button_repeat =
            xf86SetBoolOption(opts, "UpDownScrollRepeat", TRUE);
        pars->leftright_button_repeat =
            xf86SetBoolOption(opts, "LeftRightScrollRepeat", TRUE);
    }
    pars->scroll_button_repeat =
        xf86SetIntOption(opts, "ScrollButtonRepeat", 100);

    pars->locked_drags = xf86SetBoolOption(opts, "LockedDrags", FALSE);
    pars->locked_drag_time = xf86SetIntOption(opts, "LockedDragTimeout", 5000);
    pars->tap_action[RT_TAP] = xf86SetIntOption(opts, "RTCornerButton", 0);
    pars->tap_action[RB_TAP] = xf86SetIntOption(opts, "RBCornerButton", 0);
    pars->tap_action[LT_TAP] = xf86SetIntOption(opts, "LTCornerButton", 0);
    pars->tap_action[LB_TAP] = xf86SetIntOption(opts, "LBCornerButton", 0);
    pars->tap_action[F1_TAP] = xf86SetIntOption(opts, "TapButton1", tapButton1);
    pars->tap_action[F2_TAP] = xf86SetIntOption(opts, "TapButton2", tapButton2);
    pars->tap_action[F3_TAP] = xf86SetIntOption(opts, "TapButton3", tapButton3);
    pars->click_action[F1_CLICK1] =
        xf86SetIntOption(opts, "ClickFinger1", clickFinger1);
    pars->click_action[F2_CLICK1] =
        xf86SetIntOption(opts, "ClickFinger2", clickFinger2);
    pars->click_action[F3_CLICK1] =
        xf86SetIntOption(opts, "ClickFinger3", clickFinger3);
    pars->circular_scrolling =
        xf86SetBoolOption(opts, "CircularScrolling", FALSE);
    pars->circular_trigger = xf86SetIntOption(opts, "CircScrollTrigger", 0);
    pars->circular_pad = xf86SetBoolOption(opts, "CircularPad", FALSE);
    pars->palm_detect = xf86SetBoolOption(opts, "PalmDetect", FALSE);
    pars->palm_min_width = xf86SetIntOption(opts, "PalmMinWidth", palmMinWidth);
    pars->palm_min_z = xf86SetIntOption(opts, "PalmMinZ", palmMinZ);
    pars->single_tap_timeout = xf86SetIntOption(opts, "SingleTapTimeout", 180);
    pars->press_motion_min_z =
        xf86SetIntOption(opts, "PressureMotionMinZ", pressureMotionMinZ);
    pars->press_motion_max_z =
        xf86SetIntOption(opts, "PressureMotionMaxZ", pressureMotionMaxZ);

    pars->min_speed = xf86SetRealOption(opts, "MinSpeed", 0.4);
    pars->max_speed = xf86SetRealOption(opts, "MaxSpeed", 0.7);
    pars->accl = xf86SetRealOption(opts, "AccelFactor", accelFactor);
    pars->scroll_dist_circ = xf86SetRealOption(opts, "CircScrollDelta", 0.1);
    pars->coasting_speed = xf86SetRealOption(opts, "CoastingSpeed", 20.0);
    pars->coasting_friction = xf86SetRealOption(opts, "CoastingFriction", 50);
    pars->press_motion_min_factor =
        xf86SetRealOption(opts, "PressureMotionMinFactor", 1.0);
    pars->press_motion_max_factor =
        xf86SetRealOption(opts, "PressureMotionMaxFactor", 1.0);

    /* Only grab the device by default if it's not coming from a config
       backend. This way we avoid the device being added twice and sending
       duplicate events.
      */
    source = xf86CheckStrOption(opts, "_source", NULL);
    if (source == NULL || strncmp(source, "server/", 7) != 0)
        grab_event_device = TRUE;
    pars->grab_event_device = xf86SetBoolOption(opts, "GrabEventDevice", grab_event_device);

    pars->tap_and_drag_gesture =
        xf86SetBoolOption(opts, "TapAndDragGesture", TRUE);
    pars->resolution_horiz =
        xf86SetIntOption(opts, "HorizResolution", horizResolution);
    pars->resolution_vert =
        xf86SetIntOption(opts, "VertResolution", vertResolution);
    if (pars->resolution_horiz <= 0) {
        xf86IDrvMsg(pInfo, X_ERROR,
                    "Invalid X resolution, using 1 instead.\n");
        pars->resolution_horiz = 1;
    }
    if (pars->resolution_vert <= 0) {
        xf86IDrvMsg(pInfo, X_ERROR,
                    "Invalid Y resolution, using 1 instead.\n");
        pars->resolution_vert = 1;
    }

    /* Touchpad sampling rate is too low to detect all movements.
       A user may lift one finger and put another one down within the same
       EV_SYN or even between samplings so the driver doesn't notice at all.

       We limit the movement to 20 mm within one event, that is more than
       recordings showed is needed (17mm on a T440).
      */
    if (pars->resolution_horiz > 1 &&
        pars->resolution_vert > 1)
        pars->maxDeltaMM = 20;
    else {
        /* on devices without resolution set the vector length to 0.25 of
           the touchpad diagonal */
        pars->maxDeltaMM = diag * 0.25;
    }


    /* Warn about (and fix) incorrectly configured TopEdge/BottomEdge parameters */
    if (pars->top_edge > pars->bottom_edge) {
        int tmp = pars->top_edge;

        pars->top_edge = pars->bottom_edge;
        pars->bottom_edge = tmp;
        xf86IDrvMsg(pInfo, X_WARNING,
                    "TopEdge is bigger than BottomEdge. Fixing.\n");
    }

    set_primary_softbutton_areas_option(pInfo);
    if (pars->has_secondary_buttons)
        set_secondary_softbutton_areas_option(pInfo);
}

static double
SynapticsAccelerationProfile(DeviceIntPtr dev,
                             DeviceVelocityPtr vel,
                             double velocity, double thr, double acc)
{
    InputInfoPtr pInfo = dev->public.devicePrivate;
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
    SynapticsParameters *para = &priv->synpara;

    double accelfct;

    /*
     * synaptics accel was originally base on device coordinate based
     * velocity, which we recover this way so para->accl retains its scale.
     */
    velocity /= vel->const_acceleration;

    /* speed up linear with finger velocity */
    accelfct = velocity * para->accl;

    /* clip acceleration factor */
    if (accelfct > para->max_speed * acc)
        accelfct = para->max_speed * acc;
    else if (accelfct < para->min_speed)
        accelfct = para->min_speed;

    /* modify speed according to pressure */
    if (priv->moving_state == MS_TOUCHPAD_RELATIVE) {
        int minZ = para->press_motion_min_z;
        int maxZ = para->press_motion_max_z;
        double minFctr = para->press_motion_min_factor;
        double maxFctr = para->press_motion_max_factor;

        if (priv->hwState->z <= minZ) {
            accelfct *= minFctr;
        }
        else if (priv->hwState->z >= maxZ) {
            accelfct *= maxFctr;
        }
        else {
            accelfct *=
                minFctr + (priv->hwState->z - minZ) * (maxFctr -
                                                       minFctr) / (maxZ - minZ);
        }
    }

    return accelfct;
}

static int
SynapticsPreInit(InputDriverPtr drv, InputInfoPtr pInfo, int flags)
{
    SynapticsPrivate *priv;

    /* allocate memory for SynapticsPrivateRec */
    priv = calloc(1, sizeof(SynapticsPrivate));
    if (!priv)
        return BadAlloc;

    pInfo->type_name = XI_TOUCHPAD;
    pInfo->device_control = DeviceControl;
    pInfo->read_input = ReadInput;
    pInfo->control_proc = ControlProc;
    pInfo->switch_mode = SwitchMode;
    pInfo->private = priv;

    /* allocate now so we don't allocate in the signal handler */
    priv->timer = TimerSet(NULL, 0, 0, NULL, NULL);
    if (!priv->timer) {
        free(priv);
        return BadAlloc;
    }

    /* may change pInfo->options */
    if (!SetDeviceAndProtocol(pInfo)) {
        xf86IDrvMsg(pInfo, X_ERROR,
                    "Synaptics driver unable to detect protocol\n");
        goto SetupProc_fail;
    }

    priv->device = xf86FindOptionValue(pInfo->options, "Device");

    /* open the touchpad device */
    pInfo->fd = xf86OpenSerial(pInfo->options);
    if (pInfo->fd == -1) {
        xf86IDrvMsg(pInfo, X_ERROR, "Synaptics driver unable to open device\n");
        goto SetupProc_fail;
    }
    xf86ErrorFVerb(6, "port opened successfully\n");

    /* initialize variables */
    priv->repeatButtons = 0;
    priv->nextRepeat = 0;
    priv->count_packet_finger = 0;
    priv->tap_state = TS_START;
    priv->tap_button = 0;
    priv->tap_button_state = TBS_BUTTON_UP;
    priv->touch_on.millis = 0;
    priv->synpara.hyst_x = -1;
    priv->synpara.hyst_y = -1;

    /* read hardware dimensions */
    ReadDevDimensions(pInfo);

    set_default_parameters(pInfo);

    priv->comm.buffer = XisbNew(pInfo->fd, INPUT_BUFFER_SIZE);

    if (!QueryHardware(pInfo)) {
        xf86IDrvMsg(pInfo, X_ERROR,
                    "Unable to query/initialize Synaptics hardware.\n");
        goto SetupProc_fail;
    }

    xf86ProcessCommonOptions(pInfo, pInfo->options);

    if (priv->comm.buffer) {
        XisbFree(priv->comm.buffer);
        priv->comm.buffer = NULL;
    }
    SynapticsCloseFd(pInfo);

    return Success;

 SetupProc_fail:
    SynapticsCloseFd(pInfo);

    if (priv->comm.buffer)
        XisbFree(priv->comm.buffer);
    free(priv->proto_data);
    free(priv->timer);
    free(priv);
    pInfo->private = NULL;
    return BadAlloc;
}

/*
 *  Uninitialize the device.
 */
static void
SynapticsUnInit(InputDriverPtr drv, InputInfoPtr pInfo, int flags)
{
    SynapticsPrivate *priv = ((SynapticsPrivate *) pInfo->private);

    if (priv && priv->timer)
        free(priv->timer);
    if (priv && priv->proto_data)
        free(priv->proto_data);
    if (priv && priv->scroll_events_mask)
        valuator_mask_free(&priv->scroll_events_mask);
    if (priv && priv->open_slots)
        free(priv->open_slots);
    free(pInfo->private);
    pInfo->private = NULL;
    xf86DeleteInput(pInfo, 0);
}

/*
 *  Alter the control parameters for the mouse. Note that all special
 *  protocol values are handled by dix.
 */
static void
SynapticsCtrl(DeviceIntPtr device, PtrCtrl * ctrl)
{
}

static int
DeviceControl(DeviceIntPtr dev, int mode)
{
    Bool RetValue;

    switch (mode) {
    case DEVICE_INIT:
        RetValue = DeviceInit(dev);
        break;
    case DEVICE_ON:
        RetValue = DeviceOn(dev);
        break;
    case DEVICE_OFF:
        RetValue = DeviceOff(dev);
        break;
    case DEVICE_CLOSE:
        RetValue = DeviceClose(dev);
        break;
    default:
        RetValue = BadValue;
    }

    return RetValue;
}

static int
DeviceOn(DeviceIntPtr dev)
{
    InputInfoPtr pInfo = dev->public.devicePrivate;
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);

    DBG(3, "Synaptics DeviceOn called\n");

    pInfo->fd = xf86OpenSerial(pInfo->options);
    if (pInfo->fd == -1) {
        xf86IDrvMsg(pInfo, X_WARNING, "cannot open input device\n");
        return !Success;
    }

    if (priv->proto_ops->DeviceOnHook &&
        !priv->proto_ops->DeviceOnHook(pInfo, &priv->synpara))
         goto error;

    priv->comm.buffer = XisbNew(pInfo->fd, INPUT_BUFFER_SIZE);
    if (!priv->comm.buffer)
        goto error;

    xf86FlushInput(pInfo->fd);

    /* reinit the pad */
    if (!QueryHardware(pInfo))
        goto error;

    xf86AddEnabledDevice(pInfo);
    dev->public.on = TRUE;

    return Success;

error:
    if (priv->comm.buffer) {
        XisbFree(priv->comm.buffer);
        priv->comm.buffer = NULL;
    }
    SynapticsCloseFd(pInfo);
    return !Success;
}

static void
SynapticsReset(SynapticsPrivate * priv)
{
    SynapticsResetHwState(priv->hwState);
    SynapticsResetHwState(priv->local_hw_state);
    SynapticsResetHwState(priv->comm.hwState);

    memset(priv->move_hist, 0, sizeof(priv->move_hist));
    priv->hyst_center_x = 0;
    priv->hyst_center_y = 0;
    memset(&priv->scroll, 0, sizeof(priv->scroll));
    priv->count_packet_finger = 0;
    priv->finger_state = FS_UNTOUCHED;
    priv->last_motion_millis = 0;
    priv->clickpad_click_millis = 0;
    priv->last_button_area = NO_BUTTON_AREA;
    priv->tap_state = TS_START;
    priv->tap_button = 0;
    priv->tap_button_state = TBS_BUTTON_UP;
    priv->moving_state = MS_FALSE;
    priv->vert_scroll_edge_on = FALSE;
    priv->horiz_scroll_edge_on = FALSE;
    priv->vert_scroll_twofinger_on = FALSE;
    priv->horiz_scroll_twofinger_on = FALSE;
    priv->circ_scroll_on = FALSE;
    priv->circ_scroll_vert = FALSE;
    priv->mid_emu_state = MBE_OFF;
    priv->nextRepeat = 0;
    priv->lastButtons = 0;
    priv->prev_z = 0;
    priv->prevFingers = 0;
    priv->num_active_touches = 0;

    for (int i = 0; i < priv->num_slots; i++)
        priv->open_slots[i] = -1;
}

static int
DeviceOff(DeviceIntPtr dev)
{
    InputInfoPtr pInfo = dev->public.devicePrivate;
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
    Bool rc = Success;

    DBG(3, "Synaptics DeviceOff called\n");

    if (pInfo->fd != -1) {
        TimerCancel(priv->timer);
        xf86RemoveEnabledDevice(pInfo);
        SynapticsReset(priv);

        if (priv->proto_ops->DeviceOffHook &&
            !priv->proto_ops->DeviceOffHook(pInfo))
            rc = !Success;
        if (priv->comm.buffer) {
            XisbFree(priv->comm.buffer);
            priv->comm.buffer = NULL;
        }
        SynapticsCloseFd(pInfo);
    }
    dev->public.on = FALSE;
    return rc;
}

static int
DeviceClose(DeviceIntPtr dev)
{
    Bool RetValue;
    InputInfoPtr pInfo = dev->public.devicePrivate;
    SynapticsPrivate *priv = (SynapticsPrivate *) pInfo->private;

    RetValue = DeviceOff(dev);
    TimerFree(priv->timer);
    priv->timer = NULL;
    free(priv->touch_axes);
    priv->touch_axes = NULL;
    SynapticsHwStateFree(&priv->hwState);
    SynapticsHwStateFree(&priv->local_hw_state);
    SynapticsHwStateFree(&priv->comm.hwState);
    return RetValue;
}

static void
InitAxesLabels(Atom *labels, int nlabels, const SynapticsPrivate * priv)
{
    memset(labels, 0, nlabels * sizeof(Atom));
    switch (nlabels) {
    default:
    case 4:
        labels[3] = XIGetKnownProperty(AXIS_LABEL_PROP_REL_VSCROLL);
        /* FALLTHROUGH */
    case 3:
        labels[2] = XIGetKnownProperty(AXIS_LABEL_PROP_REL_HSCROLL);
        /* FALLTHROUGH */
    case 2:
        labels[1] = XIGetKnownProperty(AXIS_LABEL_PROP_REL_Y);
        /* FALLTHROUGH */
    case 1:
        labels[0] = XIGetKnownProperty(AXIS_LABEL_PROP_REL_X);
        break;
    }

    for (int i = 0; i < priv->num_mt_axes; i++) {
        SynapticsTouchAxisRec *axis = &priv->touch_axes[i];
        int axnum = nlabels - priv->num_mt_axes + i;

        labels[axnum] = XIGetKnownProperty(axis->label);
    }
}

static void
InitButtonLabels(Atom *labels, int nlabels)
{
    memset(labels, 0, nlabels * sizeof(Atom));
    switch (nlabels) {
    default:
    case 7:
        labels[6] = XIGetKnownProperty(BTN_LABEL_PROP_BTN_HWHEEL_RIGHT);
        /* FALLTHROUGH */
    case 6:
        labels[5] = XIGetKnownProperty(BTN_LABEL_PROP_BTN_HWHEEL_LEFT);
        /* FALLTHROUGH */
    case 5:
        labels[4] = XIGetKnownProperty(BTN_LABEL_PROP_BTN_WHEEL_DOWN);
        /* FALLTHROUGH */
    case 4:
        labels[3] = XIGetKnownProperty(BTN_LABEL_PROP_BTN_WHEEL_UP);
        /* FALLTHROUGH */
    case 3:
        labels[2] = XIGetKnownProperty(BTN_LABEL_PROP_BTN_RIGHT);
        /* FALLTHROUGH */
    case 2:
        labels[1] = XIGetKnownProperty(BTN_LABEL_PROP_BTN_MIDDLE);
        /* FALLTHROUGH */
    case 1:
        labels[0] = XIGetKnownProperty(BTN_LABEL_PROP_BTN_LEFT);
        break;
    }
}

static void
DeviceInitTouch(DeviceIntPtr dev, Atom *axes_labels)
{
    InputInfoPtr pInfo = dev->public.devicePrivate;
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);

    if (!priv->has_touch)
        return;

    priv->num_slots =
        priv->max_touches ? priv->max_touches : SYNAPTICS_MAX_TOUCHES;

    priv->open_slots = malloc(priv->num_slots * sizeof(int));
    if (!priv->open_slots) {
        xf86IDrvMsg(pInfo, X_ERROR,
                    "failed to allocate open touch slots array\n");
        priv->has_touch = 0;
        priv->num_slots = 0;
    }
}

static int
DeviceInit(DeviceIntPtr dev)
{
    InputInfoPtr pInfo = dev->public.devicePrivate;
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
    Atom float_type, prop;
    float tmpf;
    unsigned char map[SYN_MAX_BUTTONS + 1];
    int i;
    int min, max;
    int num_axes = 2;
    Atom btn_labels[SYN_MAX_BUTTONS] = { 0 };
    Atom *axes_labels;
    DeviceVelocityPtr pVel;

    num_axes += 2;

    num_axes += priv->num_mt_axes;

    axes_labels = calloc(num_axes, sizeof(Atom));
    if (!axes_labels) {
        xf86IDrvMsg(pInfo, X_ERROR, "failed to allocate axis labels\n");
        return !Success;
    }

    InitAxesLabels(axes_labels, num_axes, priv);
    InitButtonLabels(btn_labels, SYN_MAX_BUTTONS);

    DBG(3, "Synaptics DeviceInit called\n");

    for (i = 0; i <= SYN_MAX_BUTTONS; i++)
        map[i] = i;

    dev->public.on = FALSE;

    InitPointerDeviceStruct((DevicePtr) dev, map,
                            SYN_MAX_BUTTONS,
                            btn_labels,
                            SynapticsCtrl,
                            GetMotionHistorySize(), num_axes, axes_labels);

    /*
     * setup dix acceleration to match legacy synaptics settings, and
     * etablish a device-specific profile to do stuff like pressure-related
     * acceleration.
     */
    if (NULL != (pVel = GetDevicePredictableAccelData(dev))) {
        SetDeviceSpecificAccelerationProfile(pVel,
                                             SynapticsAccelerationProfile);

        /* float property type */
        float_type = XIGetKnownProperty(XATOM_FLOAT);

        /* translate MinAcc to constant deceleration.
         * May be overridden in xf86InitValuatorDefaults */
        tmpf = 1.0 / priv->synpara.min_speed;

        xf86IDrvMsg(pInfo, X_CONFIG,
                    "(accel) MinSpeed is now constant deceleration " "%.1f\n",
                    tmpf);
        prop = XIGetKnownProperty(ACCEL_PROP_CONSTANT_DECELERATION);
        XIChangeDeviceProperty(dev, prop, float_type, 32,
                               PropModeReplace, 1, &tmpf, FALSE);

        /* adjust accordingly */
        priv->synpara.max_speed /= priv->synpara.min_speed;
        priv->synpara.min_speed = 1.0;

        /* synaptics seems to report 80 packet/s, but dix scales for
         * 100 packet/s by default. */
        pVel->corr_mul = 12.5f; /*1000[ms]/80[/s] = 12.5 */

        xf86IDrvMsg(pInfo, X_CONFIG, "(accel) MaxSpeed is now %.2f\n",
                    priv->synpara.max_speed);
        xf86IDrvMsg(pInfo, X_CONFIG, "(accel) AccelFactor is now %.3f\n",
                    priv->synpara.accl);

        prop = XIGetKnownProperty(ACCEL_PROP_PROFILE_NUMBER);
        i = AccelProfileDeviceSpecific;
        XIChangeDeviceProperty(dev, prop, XA_INTEGER, 32,
                               PropModeReplace, 1, &i, FALSE);
    }

    /* X valuator */
    if (priv->minx < priv->maxx) {
        min = priv->minx;
        max = priv->maxx;
    }
    else {
        min = 0;
        max = -1;
    }

    xf86InitValuatorAxisStruct(dev, 0, axes_labels[0], min, max,
			       priv->resx * 1000, 0, priv->resx * 1000,
			       Relative);
    xf86InitValuatorDefaults(dev, 0);

    /* Y valuator */
    if (priv->miny < priv->maxy) {
        min = priv->miny;
        max = priv->maxy;
    }
    else {
        min = 0;
        max = -1;
    }

    xf86InitValuatorAxisStruct(dev, 1, axes_labels[1], min, max,
			       priv->resy * 1000, 0, priv->resy * 1000,
			       Relative);
    xf86InitValuatorDefaults(dev, 1);

    xf86InitValuatorAxisStruct(dev, 2, axes_labels[2], 0, -1, 0, 0, 0,
                               Relative);
    priv->scroll_axis_horiz = 2;
    xf86InitValuatorAxisStruct(dev, 3, axes_labels[3], 0, -1, 0, 0, 0,
                               Relative);
    priv->scroll_axis_vert = 3;
    priv->scroll_events_mask = valuator_mask_new(MAX_VALUATORS);
    if (!priv->scroll_events_mask) {
        free(axes_labels);
        return !Success;
    }

    SetScrollValuator(dev, priv->scroll_axis_horiz, SCROLL_TYPE_HORIZONTAL,
                      priv->synpara.scroll_dist_horiz, 0);
    SetScrollValuator(dev, priv->scroll_axis_vert, SCROLL_TYPE_VERTICAL,
                      priv->synpara.scroll_dist_vert, 0);

    DeviceInitTouch(dev, axes_labels);

    free(axes_labels);

    priv->hwState = SynapticsHwStateAlloc(priv);
    if (!priv->hwState)
        goto fail;

    priv->local_hw_state = SynapticsHwStateAlloc(priv);
    if (!priv->local_hw_state)
        goto fail;

    priv->comm.hwState = SynapticsHwStateAlloc(priv);

    InitDeviceProperties(pInfo);
    XIRegisterPropertyHandler(pInfo->dev, SetProperty, NULL, NULL);

    SynapticsReset(priv);

    return Success;

 fail:
    free(priv->local_hw_state);
    free(priv->hwState);
    free(priv->open_slots);
    return !Success;
}

/*
 * Convert from absolute X/Y coordinates to a coordinate system where
 * -1 corresponds to the left/upper edge and +1 corresponds to the
 * right/lower edge.
 */
static void
relative_coords(SynapticsPrivate * priv, int x, int y,
                double *relX, double *relY)
{
    int minX = priv->synpara.left_edge;
    int maxX = priv->synpara.right_edge;
    int minY = priv->synpara.top_edge;
    int maxY = priv->synpara.bottom_edge;
    double xCenter = (minX + maxX) / 2.0;
    double yCenter = (minY + maxY) / 2.0;

    if ((maxX - xCenter > 0) && (maxY - yCenter > 0)) {
        *relX = (x - xCenter) / (maxX - xCenter);
        *relY = (y - yCenter) / (maxY - yCenter);
    }
    else {
        *relX = 0;
        *relY = 0;
    }
}

/* return angle of point relative to center */
static double
angle(SynapticsPrivate * priv, int x, int y)
{
    double xCenter = (priv->synpara.left_edge + priv->synpara.right_edge) / 2.0;
    double yCenter = (priv->synpara.top_edge + priv->synpara.bottom_edge) / 2.0;

    return atan2(-(y - yCenter), x - xCenter);
}

/* return angle difference */
static double
diffa(double a1, double a2)
{
    double da = fmod(a2 - a1, 2 * M_PI);

    if (da < 0)
        da += 2 * M_PI;
    if (da > M_PI)
        da -= 2 * M_PI;
    return da;
}

static enum EdgeType
circular_edge_detection(SynapticsPrivate * priv, int x, int y)
{
    enum EdgeType edge = 0;
    double relX, relY, relR;

    relative_coords(priv, x, y, &relX, &relY);
    relR = SQR(relX) + SQR(relY);

    if (relR > 1) {
        /* we are outside the ellipse enclosed by the edge parameters */
        if (relX > M_SQRT1_2)
            edge |= RIGHT_EDGE;
        else if (relX < -M_SQRT1_2)
            edge |= LEFT_EDGE;

        if (relY < -M_SQRT1_2)
            edge |= TOP_EDGE;
        else if (relY > M_SQRT1_2)
            edge |= BOTTOM_EDGE;
    }

    return edge;
}

static enum EdgeType
edge_detection(SynapticsPrivate * priv, int x, int y)
{
    enum EdgeType edge = NO_EDGE;

    if (priv->synpara.circular_pad)
        return circular_edge_detection(priv, x, y);

    if (x > priv->synpara.right_edge)
        edge |= RIGHT_EDGE;
    else if (x < priv->synpara.left_edge)
        edge |= LEFT_EDGE;

    if (y < priv->synpara.top_edge)
        edge |= TOP_EDGE;
    else if (y > priv->synpara.bottom_edge)
        edge |= BOTTOM_EDGE;

    return edge;
}

/* Checks whether coordinates are in the Synaptics Area
 * or not. If no Synaptics Area is defined (i.e. if
 * priv->synpara.area_{left|right|top|bottom}_edge are
 * all set to zero), the function returns TRUE.
 */
static Bool
is_inside_active_area(SynapticsPrivate * priv, int x, int y)
{
    Bool inside_area = TRUE;

    /* If a finger is down, then it must have started inside the active_area,
       allow the motion to complete using the entire area */
    if (priv->finger_state >= FS_TOUCHED)
        return TRUE;

    if ((priv->synpara.area_left_edge != 0) &&
        (x < priv->synpara.area_left_edge))
        inside_area = FALSE;
    else if ((priv->synpara.area_right_edge != 0) &&
             (x > priv->synpara.area_right_edge))
        inside_area = FALSE;

    if ((priv->synpara.area_top_edge != 0) && (y < priv->synpara.area_top_edge))
        inside_area = FALSE;
    else if ((priv->synpara.area_bottom_edge != 0) &&
             (y > priv->synpara.area_bottom_edge))
        inside_area = FALSE;

    return inside_area;
}

static Bool
is_inside_button_area(SynapticsParameters * para, int which, int x, int y)
{
    Bool inside_area = TRUE;

    if (para->softbutton_areas[which][LEFT] == 0 &&
        para->softbutton_areas[which][RIGHT] == 0 &&
        para->softbutton_areas[which][TOP] == 0 &&
        para->softbutton_areas[which][BOTTOM] == 0)
        return FALSE;

    if (para->softbutton_areas[which][LEFT] &&
        x < para->softbutton_areas[which][LEFT])
        inside_area = FALSE;
    else if (para->softbutton_areas[which][RIGHT] &&
             x > para->softbutton_areas[which][RIGHT])
        inside_area = FALSE;
    else if (para->softbutton_areas[which][TOP] &&
             y < para->softbutton_areas[which][TOP])
        inside_area = FALSE;
    else if (para->softbutton_areas[which][BOTTOM] &&
             y > para->softbutton_areas[which][BOTTOM])
        inside_area = FALSE;

    return inside_area;
}

static Bool
is_inside_rightbutton_area(SynapticsParameters * para, int x, int y)
{
    return is_inside_button_area(para, BOTTOM_RIGHT_BUTTON_AREA, x, y);
}

static Bool
is_inside_middlebutton_area(SynapticsParameters * para, int x, int y)
{
    return is_inside_button_area(para, BOTTOM_MIDDLE_BUTTON_AREA, x, y);
}

static Bool
is_inside_sec_rightbutton_area(SynapticsParameters * para, int x, int y)
{
    return is_inside_button_area(para, TOP_RIGHT_BUTTON_AREA, x, y);
}

static Bool
is_inside_sec_middlebutton_area(SynapticsParameters * para, int x, int y)
{
    return is_inside_button_area(para, TOP_MIDDLE_BUTTON_AREA, x, y);
}

static Bool
is_inside_top_or_bottom_button_area(SynapticsParameters * para, int offset,
                                    int x, int y)
{
    Bool inside_area = TRUE;
    Bool right_valid, middle_valid;
    int top, bottom;

    /* We don't have a left button area, so we only check the y axis */
    right_valid = para->softbutton_areas[offset][TOP] ||
                  para->softbutton_areas[offset][BOTTOM];
    middle_valid = para->softbutton_areas[offset + 1][TOP] ||
                   para->softbutton_areas[offset + 1][BOTTOM];

    if (!right_valid && !middle_valid)
        return FALSE;

    /* Check both buttons are horizontally aligned */
    if (right_valid && middle_valid && (
            para->softbutton_areas[offset][TOP] !=
                para->softbutton_areas[offset + 1][TOP] ||
            para->softbutton_areas[offset][BOTTOM] !=
                para->softbutton_areas[offset + 1][BOTTOM]))
        return FALSE;

    if (right_valid) {
        top    = para->softbutton_areas[offset][TOP];
        bottom = para->softbutton_areas[offset][BOTTOM];
    }
    else {
        top    = para->softbutton_areas[offset + 1][TOP];
        bottom = para->softbutton_areas[offset + 1][BOTTOM];
    }

    if (top && y < top)
        inside_area = FALSE;
    else if (bottom && y > bottom)
        inside_area = FALSE;

    return inside_area;
}

static enum SoftButtonAreas
current_button_area(SynapticsParameters * para, int x, int y)
{
    if (is_inside_top_or_bottom_button_area(para, BOTTOM_BUTTON_AREA, x, y))
        return BOTTOM_BUTTON_AREA;
    else if (is_inside_top_or_bottom_button_area(para, TOP_BUTTON_AREA, x, y))
        return TOP_BUTTON_AREA;
    else
        return NO_BUTTON_AREA;
}

static CARD32
timerFunc(OsTimerPtr timer, CARD32 now, pointer arg)
{
    InputInfoPtr pInfo = arg;
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
    struct SynapticsHwState *hw = priv->local_hw_state;
    int delay;
#if !HAVE_THREADED_INPUT
    int sigstate = xf86BlockSIGIO();
#else
    input_lock();
#endif

    priv->hwState->millis += now - priv->timer_time;
    SynapticsCopyHwState(hw, priv->hwState);
    SynapticsResetTouchHwState(hw, FALSE);
    delay = HandleState(pInfo, hw, hw->millis, TRUE);

    priv->timer_time = now;
    priv->timer = TimerSet(priv->timer, 0, delay, timerFunc, pInfo);

#if !HAVE_THREADED_INPUT
    xf86UnblockSIGIO(sigstate);
#else
    input_unlock();
#endif

    return 0;
}

static int
clamp(int val, int min, int max)
{
    if (val < min)
        return min;
    else if (val < max)
        return val;
    else
        return max;
}

static Bool
SynapticsGetHwState(InputInfoPtr pInfo, SynapticsPrivate * priv,
                    struct SynapticsHwState *hw)
{
    return priv->proto_ops->ReadHwState(pInfo, &priv->comm, hw);
}

/*
 *  called for each full received packet from the touchpad
 */
static void
ReadInput(InputInfoPtr pInfo)
{
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
    struct SynapticsHwState *hw = priv->local_hw_state;
    int delay = 0;
    Bool newDelay = FALSE;

    SynapticsResetTouchHwState(hw, FALSE);

    while (SynapticsGetHwState(pInfo, priv, hw)) {
        /* Semi-mt device touch slots do not track touches. When there is a
         * change in the number of touches, we must disregard the temporary
         * motion changes. */
        if (priv->has_semi_mt && hw->numFingers != priv->hwState->numFingers) {
            hw->cumulative_dx = priv->hwState->cumulative_dx;
            hw->cumulative_dy = priv->hwState->cumulative_dy;
        }

        /* timer may cause actual events to lag behind (#48777) */
        if (priv->hwState->millis > hw->millis)
            hw->millis = priv->hwState->millis;

        SynapticsCopyHwState(priv->hwState, hw);
        delay = HandleState(pInfo, hw, hw->millis, FALSE);
        newDelay = TRUE;
    }

    if (newDelay) {
        priv->timer_time = GetTimeInMillis();
        priv->timer = TimerSet(priv->timer, 0, delay, timerFunc, pInfo);
    }
}

static int
HandleMidButtonEmulation(SynapticsPrivate * priv, struct SynapticsHwState *hw,
                         CARD32 now, int *delay)
{
    SynapticsParameters *para = &priv->synpara;
    Bool done = FALSE;
    int timeleft;
    int mid = 0;

    if (para->emulate_mid_button_time <= 0)
        return mid;

    while (!done) {
        switch (priv->mid_emu_state) {
        case MBE_LEFT_CLICK:
        case MBE_RIGHT_CLICK:
        case MBE_OFF:
            priv->button_delay_millis = now;
            if (hw->left) {
                priv->mid_emu_state = MBE_LEFT;
            }
            else if (hw->right) {
                priv->mid_emu_state = MBE_RIGHT;
            }
            else {
                done = TRUE;
            }
            break;
        case MBE_LEFT:
            timeleft =
                TIME_DIFF(priv->button_delay_millis +
                          para->emulate_mid_button_time, now);
            if (timeleft > 0)
                *delay = MIN(*delay, timeleft);

            /* timeout, but within the same ReadInput cycle! */
            if ((timeleft <= 0) && !hw->left) {
                priv->mid_emu_state = MBE_LEFT_CLICK;
                done = TRUE;
            }
            else if ((!hw->left) || (timeleft <= 0)) {
                hw->left = TRUE;
                priv->mid_emu_state = MBE_TIMEOUT;
                done = TRUE;
            }
            else if (hw->right) {
                priv->mid_emu_state = MBE_MID;
            }
            else {
                hw->left = FALSE;
                done = TRUE;
            }
            break;
        case MBE_RIGHT:
            timeleft =
                TIME_DIFF(priv->button_delay_millis +
                          para->emulate_mid_button_time, now);
            if (timeleft > 0)
                *delay = MIN(*delay, timeleft);

            /* timeout, but within the same ReadInput cycle! */
            if ((timeleft <= 0) && !hw->right) {
                priv->mid_emu_state = MBE_RIGHT_CLICK;
                done = TRUE;
            }
            else if (!hw->right || (timeleft <= 0)) {
                hw->right = TRUE;
                priv->mid_emu_state = MBE_TIMEOUT;
                done = TRUE;
            }
            else if (hw->left) {
                priv->mid_emu_state = MBE_MID;
            }
            else {
                hw->right = FALSE;
                done = TRUE;
            }
            break;
        case MBE_MID:
            if (!hw->left && !hw->right) {
                priv->mid_emu_state = MBE_OFF;
            }
            else {
                mid = TRUE;
                hw->left = hw->right = FALSE;
                done = TRUE;
            }
            break;
        case MBE_TIMEOUT:
            if (!hw->left && !hw->right) {
                priv->mid_emu_state = MBE_OFF;
            }
            else {
                done = TRUE;
            }
        }
    }
    return mid;
}

static enum FingerState
SynapticsDetectFinger(SynapticsPrivate * priv, struct SynapticsHwState *hw)
{
    SynapticsParameters *para = &priv->synpara;
    enum FingerState finger;

    /* finger detection thru pressure and threshold */
    if (hw->z < para->finger_low)
        return FS_UNTOUCHED;

    if (priv->finger_state == FS_BLOCKED)
        return FS_BLOCKED;

    if (hw->z > para->finger_high && priv->finger_state == FS_UNTOUCHED)
        finger = FS_TOUCHED;
    else
        finger = priv->finger_state;

    if (!para->palm_detect)
        return finger;

    /* palm detection */

    if ((hw->z > para->palm_min_z) && (hw->fingerWidth > para->palm_min_width))
        return FS_BLOCKED;

    if (priv->has_mt_palm_detect)
        return finger;

    if (hw->x == 0 || priv->finger_state == FS_UNTOUCHED)
        priv->avg_width = 0;
    else
        priv->avg_width += (hw->fingerWidth - priv->avg_width + 1) / 2;

    if (finger != FS_UNTOUCHED && priv->finger_state == FS_UNTOUCHED) {
        int safe_width = MAX(hw->fingerWidth, priv->avg_width);

        if (hw->numFingers > 1 ||       /* more than one finger -> not a palm */
            ((safe_width < 6) && (priv->prev_z < para->finger_high)) || /* thin finger, distinct touch -> not a palm */
            ((safe_width < 7) && (priv->prev_z < para->finger_high / 2))) {     /* thin finger, distinct touch -> not a palm */
            /* leave finger value as is */
        }
        else if (hw->z > priv->prev_z + 1)      /* z not stable, may be a palm */
            finger = FS_UNTOUCHED;
        else if (hw->z < priv->prev_z - 5)      /* z not stable, may be a palm */
            finger = FS_UNTOUCHED;
        else if (hw->fingerWidth > para->palm_min_width)        /* finger width too large -> probably palm */
            finger = FS_UNTOUCHED;
    }
    priv->prev_z = hw->z;

    return finger;
}

static void
SelectTapButton(SynapticsPrivate * priv, enum EdgeType edge)
{
    enum TapEvent tap;

    if (priv->synpara.touchpad_off == TOUCHPAD_TAP_OFF) {
        priv->tap_button = 0;
        return;
    }

    switch (priv->tap_max_fingers) {
    case 1:
        switch (edge) {
        case RIGHT_TOP_EDGE:
            DBG(7, "right top edge\n");
            tap = RT_TAP;
            break;
        case RIGHT_BOTTOM_EDGE:
            DBG(7, "right bottom edge\n");
            tap = RB_TAP;
            break;
        case LEFT_TOP_EDGE:
            DBG(7, "left top edge\n");
            tap = LT_TAP;
            break;
        case LEFT_BOTTOM_EDGE:
            DBG(7, "left bottom edge\n");
            tap = LB_TAP;
            break;
        default:
            DBG(7, "no edge\n");
            tap = F1_TAP;
            break;
        }
        break;
    case 2:
        DBG(7, "two finger tap\n");
        tap = F2_TAP;
        break;
    case 3:
        DBG(7, "three finger tap\n");
        tap = F3_TAP;
        break;
    default:
        priv->tap_button = 0;
        return;
    }

    priv->tap_button = priv->synpara.tap_action[tap];
    priv->tap_button = clamp(priv->tap_button, 0, SYN_MAX_BUTTONS);
}

static void
SetTapState(SynapticsPrivate * priv, enum TapState tap_state, CARD32 millis)
{
    DBG(3, "SetTapState - %d -> %d (millis:%u)\n", priv->tap_state, tap_state,
        millis);
    switch (tap_state) {
    case TS_START:
        priv->tap_button_state = TBS_BUTTON_UP;
        priv->tap_max_fingers = 0;
        break;
    case TS_1:
        priv->tap_button_state = TBS_BUTTON_UP;
        break;
    case TS_2A:
	priv->tap_button_state = TBS_BUTTON_UP;
        break;
    case TS_2B:
        priv->tap_button_state = TBS_BUTTON_UP;
        break;
    case TS_3:
        priv->tap_button_state = TBS_BUTTON_DOWN;
        break;
    case TS_SINGLETAP:
	priv->tap_button_state = TBS_BUTTON_DOWN;
        priv->touch_on.millis = millis;
        break;
    default:
        break;
    }
    priv->tap_state = tap_state;
}

static void
SetMovingState(SynapticsPrivate * priv, enum MovingState moving_state,
               CARD32 millis)
{
    DBG(7, "SetMovingState - %d -> %d center at %d/%d (millis:%u)\n",
        priv->moving_state, moving_state, priv->hwState->x, priv->hwState->y,
        millis);

    priv->moving_state = moving_state;
}

static int
GetTimeOut(SynapticsPrivate * priv)
{
    SynapticsParameters *para = &priv->synpara;

    switch (priv->tap_state) {
    case TS_1:
    case TS_3:
    case TS_5:
        return para->tap_time;
    case TS_SINGLETAP:
        return para->click_time;
    case TS_2A:
        return para->single_tap_timeout;
    case TS_2B:
        return para->tap_time_2;
    case TS_4:
        return para->locked_drag_time;
    default:
        return -1;              /* No timeout */
    }
}

static int
HandleTapProcessing(SynapticsPrivate * priv, struct SynapticsHwState *hw,
                    CARD32 now, enum FingerState finger,
                    Bool inside_active_area)
{
    SynapticsParameters *para = &priv->synpara;
    Bool touch, release, is_timeout, move, press;
    int timeleft, timeout;
    enum EdgeType edge;
    int delay = 1000000000;

    if (para->touchpad_off == TOUCHPAD_OFF ||
        priv->finger_state == FS_BLOCKED)
        return delay;

    touch = finger >= FS_TOUCHED && priv->finger_state == FS_UNTOUCHED;
    release = finger == FS_UNTOUCHED && priv->finger_state >= FS_TOUCHED;
    move = (finger >= FS_TOUCHED &&
            (priv->tap_max_fingers <=
             ((priv->horiz_scroll_twofinger_on ||
               priv->vert_scroll_twofinger_on) ? 2 : 1)) &&
            (priv->prevFingers == hw->numFingers &&
             ((abs(hw->x - priv->touch_on.x) >= para->tap_move) ||
              (abs(hw->y - priv->touch_on.y) >= para->tap_move))));
    press = (hw->left || hw->right || hw->middle);

    if (touch) {
        priv->touch_on.x = hw->x;
        priv->touch_on.y = hw->y;
        priv->touch_on.millis = now;
    }
    else if (release) {
        priv->touch_on.millis = now;
    }
    if (hw->z > para->finger_high)
        if (priv->tap_max_fingers < hw->numFingers)
            priv->tap_max_fingers = hw->numFingers;
    timeout = GetTimeOut(priv);
    timeleft = TIME_DIFF(priv->touch_on.millis + timeout, now);
    is_timeout = timeleft <= 0;

 restart:
    switch (priv->tap_state) {
    case TS_START:
        if (touch)
            SetTapState(priv, TS_1, now);
        break;
    case TS_1:
        if (para->clickpad && press) {
            SetTapState(priv, TS_CLICKPAD_MOVE, now);
            goto restart;
        }
        if (move) {
            SetMovingState(priv, MS_TOUCHPAD_RELATIVE, now);
            SetTapState(priv, TS_MOVE, now);
            goto restart;
        }
        else if (is_timeout) {
            if (finger == FS_TOUCHED) {
                SetMovingState(priv, MS_TOUCHPAD_RELATIVE, now);
            }
            SetTapState(priv, TS_MOVE, now);
            goto restart;
        }
        else if (release) {
            edge = edge_detection(priv, priv->touch_on.x, priv->touch_on.y);
            SelectTapButton(priv, edge);
            /* Disable taps outside of the active area */
            if (!inside_active_area) {
                priv->tap_button = 0;
            }
            SetTapState(priv, TS_2A, now);
        }
        break;
    case TS_MOVE:
        if (para->clickpad && press) {
            SetTapState(priv, TS_CLICKPAD_MOVE, now);
            goto restart;
        }
        if (release) {
            SetMovingState(priv, MS_FALSE, now);
            SetTapState(priv, TS_START, now);
        }
        break;
    case TS_2A:
        if (touch)
            SetTapState(priv, TS_3, now);
        else if (is_timeout)
            SetTapState(priv, TS_SINGLETAP, now);
        break;
    case TS_2B:
        if (touch)
            SetTapState(priv, TS_3, now);
        else if (is_timeout)
            SetTapState(priv, TS_SINGLETAP, now);
        break;
    case TS_SINGLETAP:
        if (touch)
            SetTapState(priv, TS_1, now);
        else if (is_timeout)
            SetTapState(priv, TS_START, now);
        break;
    case TS_3:
        if (move) {
            if (para->tap_and_drag_gesture) {
                SetMovingState(priv, MS_TOUCHPAD_RELATIVE, now);
                SetTapState(priv, TS_DRAG, now);
            }
            else {
                SetTapState(priv, TS_1, now);
            }
            goto restart;
        }
        else if (is_timeout) {
            if (para->tap_and_drag_gesture) {
                if (finger == FS_TOUCHED) {
                    SetMovingState(priv, MS_TOUCHPAD_RELATIVE, now);
                }
                SetTapState(priv, TS_DRAG, now);
            }
            else {
                SetTapState(priv, TS_1, now);
            }
            goto restart;
        }
        else if (release) {
            SetTapState(priv, TS_2B, now);
        }
        break;
    case TS_DRAG:
        if (para->clickpad && press) {
            SetTapState(priv, TS_CLICKPAD_MOVE, now);
            goto restart;
        }
        if (move)
            SetMovingState(priv, MS_TOUCHPAD_RELATIVE, now);
        if (release) {
            SetMovingState(priv, MS_FALSE, now);
            if (para->locked_drags) {
                SetTapState(priv, TS_4, now);
            }
            else {
                SetTapState(priv, TS_START, now);
            }
        }
        break;
    case TS_4:
        if (is_timeout) {
            SetTapState(priv, TS_START, now);
            goto restart;
        }
        if (touch)
            SetTapState(priv, TS_5, now);
        break;
    case TS_5:
        if (is_timeout || move) {
            SetTapState(priv, TS_DRAG, now);
            goto restart;
        }
        else if (release) {
            SetMovingState(priv, MS_FALSE, now);
            SetTapState(priv, TS_START, now);
        }
        break;
    case TS_CLICKPAD_MOVE:
        /* Disable scrolling once a button is pressed on a clickpad */
        priv->vert_scroll_edge_on = FALSE;
        priv->horiz_scroll_edge_on = FALSE;
        priv->vert_scroll_twofinger_on = FALSE;
        priv->horiz_scroll_twofinger_on = FALSE;

        /* Assume one touch is only for holding the clickpad button down */
        if (hw->numFingers > 1)
            hw->numFingers--;
        SetMovingState(priv, MS_TOUCHPAD_RELATIVE, now);
        if (!press) {
            SetMovingState(priv, MS_FALSE, now);
            SetTapState(priv, TS_MOVE, now);
            priv->count_packet_finger = 0;
        }
        break;
    }

    timeout = GetTimeOut(priv);
    if (timeout >= 0) {
        timeleft = TIME_DIFF(priv->touch_on.millis + timeout, now);
        delay = clamp(timeleft, 1, delay);
    }
    return delay;
}

#define HIST(a) (priv->move_hist[((priv->hist_index - (a) + SYNAPTICS_MOVE_HISTORY) % SYNAPTICS_MOVE_HISTORY)])
#define HIST_DELTA(a, b, e) ((HIST((a)).e) - (HIST((b)).e))

static void
store_history(SynapticsPrivate * priv, int x, int y, CARD32 millis)
{
    int idx = (priv->hist_index + 1) % SYNAPTICS_MOVE_HISTORY;

    priv->move_hist[idx].x = x;
    priv->move_hist[idx].y = y;
    priv->move_hist[idx].millis = millis;
    priv->hist_index = idx;
    if (priv->count_packet_finger < SYNAPTICS_MOVE_HISTORY)
        priv->count_packet_finger++;
}

/*
 * Estimate the slope for the data sequence [x3, x2, x1, x0] by using
 * linear regression to fit a line to the data and use the slope of the
 * line.
 */
static double
estimate_delta(double x0, double x1, double x2, double x3)
{
    return x0 * 0.3 + x1 * 0.1 - x2 * 0.1 - x3 * 0.3;
}

/**
 * Applies hysteresis. center is shifted such that it is in range with
 * in by the margin again. The new center is returned.
 * @param in the current value
 * @param center the current center
 * @param margin the margin to center in which no change is applied
 * @return the new center (which might coincide with the previous)
 */
static int
hysteresis(int in, int center, int margin)
{
    int diff = in - center;

    if (abs(diff) <= margin) {
        diff = 0;
    }
    else if (diff > margin) {
        diff -= margin;
    }
    else if (diff < -margin) {
        diff += margin;
    }
    return center + diff;
}

static void
get_delta(SynapticsPrivate *priv, const struct SynapticsHwState *hw,
          enum EdgeType edge, double *dx, double *dy)
{
    *dx = hw->x - HIST(0).x;
    *dy = hw->y - HIST(0).y;
}

/* Vector length, but not sqrt'ed, we only need it for comparison */
static inline double
vlenpow2(double x, double y)
{
    return x * x + y * y;
}

/**
 * Compute relative motion ('deltas') including edge motion.
 */
static int
ComputeDeltas(SynapticsPrivate * priv, const struct SynapticsHwState *hw,
              enum EdgeType edge, int *dxP, int *dyP, Bool inside_area)
{
    enum MovingState moving_state;
    double dx, dy;
    double vlen;
    int delay = 1000000000;

    dx = dy = 0;

    moving_state = priv->moving_state;
    if (moving_state == MS_FALSE) {
        switch (priv->tap_state) {
        case TS_MOVE:
        case TS_DRAG:
            moving_state = MS_TOUCHPAD_RELATIVE;
            break;
        case TS_1:
        case TS_3:
        case TS_5:
            moving_state = MS_TOUCHPAD_RELATIVE;
            break;
        default:
            break;
        }
    }

    if (!inside_area || !moving_state || priv->finger_state == FS_BLOCKED ||
        priv->vert_scroll_edge_on || priv->horiz_scroll_edge_on ||
        priv->vert_scroll_twofinger_on || priv->horiz_scroll_twofinger_on ||
        priv->circ_scroll_on || priv->prevFingers != hw->numFingers ||
        (moving_state == MS_TOUCHPAD_RELATIVE && hw->numFingers != 1)) {
        /* reset packet counter. */
        priv->count_packet_finger = 0;
        goto out;
    }

    /* To create the illusion of fluid motion, call back at roughly the report
     * rate, even in the absence of new hardware events; see comment above
     * POLL_MS declaration. */
    delay = MIN(delay, POLL_MS);

    if (priv->count_packet_finger <= 1)
        goto out;               /* skip the lot */

    if (moving_state == MS_TOUCHPAD_RELATIVE)
        get_delta(priv, hw, edge, &dx, &dy);

 out:
    priv->prevFingers = hw->numFingers;

    vlen = vlenpow2(dx/priv->synpara.resolution_horiz,
                    dy/priv->synpara.resolution_vert);

    if (vlen > priv->synpara.maxDeltaMM * priv->synpara.maxDeltaMM) {
        dx = 0;
        dy = 0;
    }

    *dxP = dx;
    *dyP = dy;

    return delay;
}

static double
estimate_delta_circ(SynapticsPrivate * priv)
{
    double a1 = angle(priv, HIST(3).x, HIST(3).y);
    double a2 = angle(priv, HIST(2).x, HIST(2).y);
    double a3 = angle(priv, HIST(1).x, HIST(1).y);
    double a4 = angle(priv, HIST(0).x, HIST(0).y);
    double d1 = diffa(a2, a1);
    double d2 = d1 + diffa(a3, a2);
    double d3 = d2 + diffa(a4, a3);

    return estimate_delta(d3, d2, d1, 0);
}

/* vert and horiz are to know which direction to start coasting
 * circ is true if the user had been circular scrolling.
 */
static void
start_coasting(SynapticsPrivate * priv, struct SynapticsHwState *hw,
               Bool vert, Bool horiz, Bool circ)
{
    SynapticsParameters *para = &priv->synpara;

    priv->scroll.coast_delta_y = 0.0;
    priv->scroll.coast_delta_x = 0.0;

    if ((priv->scroll.packets_this_scroll > 3) && (para->coasting_speed > 0.0)) {
        double pkt_time = HIST_DELTA(0, 3, millis) / 1000.0;

        if (vert && !circ) {
            double dy =
                estimate_delta(HIST(0).y, HIST(1).y, HIST(2).y, HIST(3).y);
            if (pkt_time > 0) {
                double scrolls_per_sec = (dy / abs(para->scroll_dist_vert)) / pkt_time;

                if (fabs(scrolls_per_sec) >= para->coasting_speed) {
                    priv->scroll.coast_speed_y = scrolls_per_sec;
                    priv->scroll.coast_delta_y = (hw->y - priv->scroll.last_y);
                }
            }
        }
        if (horiz && !circ) {
            double dx =
                estimate_delta(HIST(0).x, HIST(1).x, HIST(2).x, HIST(3).x);
            if (pkt_time > 0) {
                double scrolls_per_sec = (dx / abs(para->scroll_dist_vert)) / pkt_time;

                if (fabs(scrolls_per_sec) >= para->coasting_speed) {
                    priv->scroll.coast_speed_x = scrolls_per_sec;
                    priv->scroll.coast_delta_x = (hw->x - priv->scroll.last_x);
                }
            }
        }
        if (circ) {
            double da = estimate_delta_circ(priv);

            if (pkt_time > 0) {
                double scrolls_per_sec = (da / para->scroll_dist_circ) / pkt_time;

                if (fabs(scrolls_per_sec) >= para->coasting_speed) {
                    if (vert) {
                        priv->scroll.coast_speed_y = scrolls_per_sec;
                        priv->scroll.coast_delta_y =
                            diffa(priv->scroll.last_a,
                                  angle(priv, hw->x, hw->y));
                    }
                    else if (horiz) {
                        priv->scroll.coast_speed_x = scrolls_per_sec;
                        priv->scroll.coast_delta_x =
                            diffa(priv->scroll.last_a,
                                  angle(priv, hw->x, hw->y));
                    }
                }
            }
        }
    }
    priv->scroll.packets_this_scroll = 0;
}

static void
stop_coasting(SynapticsPrivate * priv)
{
    priv->scroll.coast_speed_x = 0;
    priv->scroll.coast_speed_y = 0;
    priv->scroll.packets_this_scroll = 0;
}

static int
HandleScrolling(SynapticsPrivate * priv, struct SynapticsHwState *hw,
                enum EdgeType edge, Bool finger)
{
    SynapticsParameters *para = &priv->synpara;
    int delay = 1000000000;

    if (priv->synpara.touchpad_off == TOUCHPAD_TAP_OFF ||
        priv->synpara.touchpad_off == TOUCHPAD_OFF ||
        priv->finger_state == FS_BLOCKED) {
        stop_coasting(priv);
        priv->circ_scroll_on = FALSE;
        priv->vert_scroll_edge_on = FALSE;
        priv->horiz_scroll_edge_on = FALSE;
        priv->vert_scroll_twofinger_on = FALSE;
        priv->horiz_scroll_twofinger_on = FALSE;
        return delay;
    }

    /* scroll detection */
    if (finger && priv->finger_state == FS_UNTOUCHED) {
        stop_coasting(priv);
        priv->scroll.delta_y = 0;
        priv->scroll.delta_x = 0;
        if (para->circular_scrolling) {
            if ((para->circular_trigger == 0 && edge) ||
                (para->circular_trigger == 1 && edge & TOP_EDGE) ||
                (para->circular_trigger == 2 && edge & TOP_EDGE &&
                 edge & RIGHT_EDGE) || (para->circular_trigger == 3 &&
                                        edge & RIGHT_EDGE) ||
                (para->circular_trigger == 4 && edge & RIGHT_EDGE &&
                 edge & BOTTOM_EDGE) || (para->circular_trigger == 5 &&
                                         edge & BOTTOM_EDGE) ||
                (para->circular_trigger == 6 && edge & BOTTOM_EDGE &&
                 edge & LEFT_EDGE) || (para->circular_trigger == 7 &&
                                       edge & LEFT_EDGE) ||
                (para->circular_trigger == 8 && edge & LEFT_EDGE &&
                 edge & TOP_EDGE)) {
                priv->circ_scroll_on = TRUE;
                priv->circ_scroll_vert = TRUE;
                priv->scroll.last_a = angle(priv, hw->x, hw->y);
                DBG(7, "circular scroll detected on edge\n");
            }
        }
    }
    if (!priv->circ_scroll_on) {
        if (finger) {
            if (hw->numFingers == 2) {
                if (!priv->vert_scroll_twofinger_on &&
                    (para->scroll_twofinger_vert) &&
                    (para->scroll_dist_vert != 0)) {
                    stop_coasting(priv);
                    priv->vert_scroll_twofinger_on = TRUE;
                    priv->vert_scroll_edge_on = FALSE;
                    priv->scroll.last_y = hw->y;
                    DBG(7, "vert two-finger scroll detected\n");
                }
                if (!priv->horiz_scroll_twofinger_on &&
                    (para->scroll_twofinger_horiz) &&
                    (para->scroll_dist_horiz != 0)) {
                    stop_coasting(priv);
                    priv->horiz_scroll_twofinger_on = TRUE;
                    priv->horiz_scroll_edge_on = FALSE;
                    priv->scroll.last_x = hw->x;
                    DBG(7, "horiz two-finger scroll detected\n");
                }
            }
        }
        if (finger && priv->finger_state == FS_UNTOUCHED) {
            if (!priv->vert_scroll_twofinger_on &&
                !priv->horiz_scroll_twofinger_on) {
                if ((para->scroll_edge_vert) && (para->scroll_dist_vert != 0) &&
                    (edge & RIGHT_EDGE)) {
                    priv->vert_scroll_edge_on = TRUE;
                    priv->scroll.last_y = hw->y;
                    DBG(7, "vert edge scroll detected on right edge\n");
                }
                if ((para->scroll_edge_horiz) && (para->scroll_dist_horiz != 0)
                    && (edge & BOTTOM_EDGE)) {
                    priv->horiz_scroll_edge_on = TRUE;
                    priv->scroll.last_x = hw->x;
                    DBG(7, "horiz edge scroll detected on bottom edge\n");
                }
            }
        }
    }
    {
        Bool oldv = priv->vert_scroll_twofinger_on || priv->vert_scroll_edge_on
            || (priv->circ_scroll_on && priv->circ_scroll_vert);

        Bool oldh = priv->horiz_scroll_twofinger_on ||
            priv->horiz_scroll_edge_on || (priv->circ_scroll_on &&
                                           !priv->circ_scroll_vert);

        Bool oldc = priv->circ_scroll_on;

        if (priv->circ_scroll_on && !finger) {
            /* circular scroll locks in until finger is raised */
            DBG(7, "cicular scroll off\n");
            priv->circ_scroll_on = FALSE;
        }

        if (!finger || hw->numFingers != 2) {
            if (priv->vert_scroll_twofinger_on) {
                DBG(7, "vert two-finger scroll off\n");
                priv->vert_scroll_twofinger_on = FALSE;
            }
            if (priv->horiz_scroll_twofinger_on) {
                DBG(7, "horiz two-finger scroll off\n");
                priv->horiz_scroll_twofinger_on = FALSE;
            }
        }

        if (priv->vert_scroll_edge_on && (!(edge & RIGHT_EDGE) || !finger)) {
            DBG(7, "vert edge scroll off\n");
            priv->vert_scroll_edge_on = FALSE;
        }
        if (priv->horiz_scroll_edge_on && (!(edge & BOTTOM_EDGE) || !finger)) {
            DBG(7, "horiz edge scroll off\n");
            priv->horiz_scroll_edge_on = FALSE;
        }
        /* If we were corner edge scrolling (coasting),
         * but no longer in corner or raised a finger, then stop coasting. */
        if (para->scroll_edge_corner &&
            (priv->scroll.coast_speed_x || priv->scroll.coast_speed_y)) {
            Bool is_in_corner = ((edge & RIGHT_EDGE) &&
                                 (edge & (TOP_EDGE | BOTTOM_EDGE))) ||
                ((edge & BOTTOM_EDGE) && (edge & (LEFT_EDGE | RIGHT_EDGE)));
            if (!is_in_corner || !finger) {
                DBG(7, "corner edge scroll off\n");
                stop_coasting(priv);
            }
        }
        /* if we were scrolling, but couldn't corner edge scroll,
         * and are no longer scrolling, then start coasting */
        oldv = oldv && !(priv->vert_scroll_twofinger_on ||
                         priv->vert_scroll_edge_on || (priv->circ_scroll_on &&
                                                       priv->circ_scroll_vert));

        oldh = oldh && !(priv->horiz_scroll_twofinger_on ||
                         priv->horiz_scroll_edge_on || (priv->circ_scroll_on &&
                                                        !priv->
                                                        circ_scroll_vert));

        oldc = oldc && !priv->circ_scroll_on;

        if ((oldv || oldh) && !para->scroll_edge_corner) {
            start_coasting(priv, hw, oldv, oldh, oldc);
        }
    }

    /* if hitting a corner (top right or bottom right) while vertical
     * scrolling is active, consider starting corner edge scrolling or
     * switching over to circular scrolling smoothly */
    if (priv->vert_scroll_edge_on && !priv->horiz_scroll_edge_on &&
        (edge & RIGHT_EDGE) && (edge & (TOP_EDGE | BOTTOM_EDGE))) {
        if (para->scroll_edge_corner) {
            if (priv->scroll.coast_speed_y == 0) {
                /* FYI: We can generate multiple start_coasting requests if
                 * we're in the corner, but we were moving so slowly when we
                 * got here that we didn't actually start coasting. */
                DBG(7, "corner edge scroll on\n");
                start_coasting(priv, hw, TRUE, FALSE, FALSE);
            }
        }
        else if (para->circular_scrolling) {
            priv->vert_scroll_edge_on = FALSE;
            priv->circ_scroll_on = TRUE;
            priv->circ_scroll_vert = TRUE;
            priv->scroll.last_a = angle(priv, hw->x, hw->y);
            DBG(7, "switching to circular scrolling\n");
        }
    }
    /* Same treatment for horizontal scrolling */
    if (priv->horiz_scroll_edge_on && !priv->vert_scroll_edge_on &&
        (edge & BOTTOM_EDGE) && (edge & (LEFT_EDGE | RIGHT_EDGE))) {
        if (para->scroll_edge_corner) {
            if (priv->scroll.coast_speed_x == 0) {
                /* FYI: We can generate multiple start_coasting requests if
                 * we're in the corner, but we were moving so slowly when we
                 * got here that we didn't actually start coasting. */
                DBG(7, "corner edge scroll on\n");
                start_coasting(priv, hw, FALSE, TRUE, FALSE);
            }
        }
        else if (para->circular_scrolling) {
            priv->horiz_scroll_edge_on = FALSE;
            priv->circ_scroll_on = TRUE;
            priv->circ_scroll_vert = FALSE;
            priv->scroll.last_a = angle(priv, hw->x, hw->y);
            DBG(7, "switching to circular scrolling\n");
        }
    }

    if (priv->vert_scroll_edge_on || priv->horiz_scroll_edge_on ||
        priv->vert_scroll_twofinger_on || priv->horiz_scroll_twofinger_on ||
        priv->circ_scroll_on) {
        priv->scroll.packets_this_scroll++;
    }

    if (priv->vert_scroll_edge_on || priv->vert_scroll_twofinger_on) {
        /* + = down, - = up */
        if (para->scroll_dist_vert != 0 && hw->y != priv->scroll.last_y) {
            priv->scroll.delta_y += (hw->y - priv->scroll.last_y);
            priv->scroll.last_y = hw->y;
        }
    }
    if (priv->horiz_scroll_edge_on || priv->horiz_scroll_twofinger_on) {
        /* + = right, - = left */
        if (para->scroll_dist_horiz != 0 && hw->x != priv->scroll.last_x) {
            priv->scroll.delta_x += (hw->x - priv->scroll.last_x);
            priv->scroll.last_x = hw->x;
        }
    }
    if (priv->circ_scroll_on) {
        /* + = counter clockwise, - = clockwise */
        double delta = para->scroll_dist_circ;
        double diff = diffa(priv->scroll.last_a, angle(priv, hw->x, hw->y));

        if (delta >= 0.005 && diff != 0.0) {
            if (priv->circ_scroll_vert)
                priv->scroll.delta_y -= diff / delta * para->scroll_dist_vert;
            else
                priv->scroll.delta_x -= diff / delta * para->scroll_dist_horiz;
            priv->scroll.last_a = angle(priv, hw->x, hw->y);
        }
    }

    if (priv->scroll.coast_speed_y) {
        double dtime = (hw->millis - priv->scroll.last_millis) / 1000.0;
        double ddy = para->coasting_friction * dtime;

        priv->scroll.delta_y += priv->scroll.coast_speed_y * dtime * abs(para->scroll_dist_vert);
        delay = MIN(delay, POLL_MS);
        if (fabs(priv->scroll.coast_speed_y) < ddy) {
            priv->scroll.coast_speed_y = 0;
            priv->scroll.packets_this_scroll = 0;
        }
        else {
            priv->scroll.coast_speed_y +=
                (priv->scroll.coast_speed_y < 0 ? ddy : -ddy);
        }
    }

    if (priv->scroll.coast_speed_x) {
        double dtime = (hw->millis - priv->scroll.last_millis) / 1000.0;
        double ddx = para->coasting_friction * dtime;
        priv->scroll.delta_x += priv->scroll.coast_speed_x * dtime * abs(para->scroll_dist_horiz);
        delay = MIN(delay, POLL_MS);
        if (fabs(priv->scroll.coast_speed_x) < ddx) {
            priv->scroll.coast_speed_x = 0;
            priv->scroll.packets_this_scroll = 0;
        }
        else {
            priv->scroll.coast_speed_x +=
                (priv->scroll.coast_speed_x < 0 ? ddx : -ddx);
        }
    }

    return delay;
}

/**
 * Check if any 2+ fingers are close enough together to assume this is a
 * ClickFinger action.
 */
static int
clickpad_guess_clickfingers(SynapticsPrivate * priv,
                            struct SynapticsHwState *hw)
{
    int nfingers = 0;
    uint32_t close_point = 0; /* 1 bit for each point close to another one */

    if (hw->num_mt_mask > sizeof(close_point) * 8) {
        ErrorFSigSafe("BUG: synaptics: hw->num_mt_mask too big %d\n", hw->num_mt_mask);
        xorg_backtrace();
        return 0;
    }

    for (int i = 0; i < hw->num_mt_mask - 1; i++) {
        ValuatorMask *f1;

        if (hw->slot_state[i] == SLOTSTATE_EMPTY ||
            hw->slot_state[i] == SLOTSTATE_CLOSE)
            continue;

        f1 = hw->mt_mask[i];

        for (int j = i + 1; j < hw->num_mt_mask; j++) {
            ValuatorMask *f2;
            double x1, x2, y1, y2;

            if (hw->slot_state[j] == SLOTSTATE_EMPTY ||
                hw->slot_state[j] == SLOTSTATE_CLOSE)
                continue;

            f2 = hw->mt_mask[j];

            x1 = valuator_mask_get_double(f1, 0);
            y1 = valuator_mask_get_double(f1, 1);

            x2 = valuator_mask_get_double(f2, 0);
            y2 = valuator_mask_get_double(f2, 1);

            /* FIXME: fingers closer together than 30% of touchpad width, but
             * really, this should be dependent on the touchpad size. Also,
             * you'll need to find a touchpad that doesn't lie about it's
             * size. Good luck. */
            if (fabs(x1 - x2) < (priv->maxx - priv->minx) * .3 &&
                fabs(y1 - y2) < (priv->maxy - priv->miny) * .3) {
                close_point |= (1 << j);
                close_point |= (1 << i);
            }
        }
    }

    while (close_point > 0) {
        nfingers += close_point & 0x1;
        close_point >>= 1;
    }

    /* Some trackpads touchpad only track two touchpoints but announce
     * BTN_TOOL_TRIPLETAP (which sets hw->numFingers to 3), when this happens
     * the user likely intents to do a 3 finger click, so handle it as such.
     */
    if (hw->numFingers >= 3 && hw->num_mt_mask < 3)
        nfingers = 3;

    return nfingers;
}

static void
handle_clickfinger(SynapticsPrivate * priv, struct SynapticsHwState *hw)
{
    SynapticsParameters *para = &priv->synpara;
    int action = 0;
    int nfingers = hw->numFingers;

    /* if this is a clickpad, clickfinger handling is:
     * one finger down: no action, this is a normal click
     * two fingers down: F2_CLICK
     * three fingers down: F3_CLICK
     */

    if (para->clickpad)
        nfingers = clickpad_guess_clickfingers(priv, hw);

    switch (nfingers) {
    case 1:
        action = para->click_action[F1_CLICK1];
        break;
    case 2:
        action = para->click_action[F2_CLICK1];
        break;
    case 3:
        action = para->click_action[F3_CLICK1];
        break;
    }
    switch (action) {
    case 1:
        hw->left = 1 | BTN_EMULATED_FLAG;
        break;
    case 2:
        hw->left = 0;
        hw->middle = 1 | BTN_EMULATED_FLAG;
        break;
    case 3:
        hw->left = 0;
        hw->right = 1 | BTN_EMULATED_FLAG;
        break;
    }
}

/* Adjust the hardware state according to the extra buttons (if the touchpad
 * has any and not many touchpads do these days). These buttons are up/down
 * tilt buttons and/or left/right buttons that then map into a specific
 * function (or scrolling into).
 */
static Bool
adjust_state_from_scrollbuttons(const InputInfoPtr pInfo,
                                struct SynapticsHwState *hw)
{
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
    SynapticsParameters *para = &priv->synpara;
    Bool double_click = FALSE;

    if (!para->updown_button_scrolling) {
        if (hw->down) {         /* map down button to middle button */
            hw->middle = TRUE;
        }

        if (hw->up) {           /* up button generates double click */
            if (!priv->prev_up)
                double_click = TRUE;
        }
        priv->prev_up = hw->up;

        /* reset up/down button events */
        hw->up = hw->down = FALSE;
    }

    /* Left/right button scrolling, or middle clicks */
    if (!para->leftright_button_scrolling) {
        if (hw->multi[2] || hw->multi[3])
            hw->middle = TRUE;

        /* reset left/right button events */
        hw->multi[2] = hw->multi[3] = FALSE;
    }

    return double_click;
}

static void
update_hw_button_state(const InputInfoPtr pInfo, struct SynapticsHwState *hw,
                       CARD32 now, int *delay)
{
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
    SynapticsParameters *para = &priv->synpara;

    /* Treat the first two multi buttons as up/down for now. */
    hw->up |= hw->multi[0];
    hw->down |= hw->multi[1];

    /* 3rd button emulation */
    hw->middle |= HandleMidButtonEmulation(priv, hw, now, delay);

    /* If this is a clickpad and the user clicks in a soft button area, press
     * the soft button instead. */
    if (para->clickpad) {
        /* hw->left is down, but no other buttons were already down */
        if (!(priv->lastButtons & 7) && hw->left && !hw->right && !hw->middle) {
            /* If the finger down event is delayed, the x and y
             * coordinates are stale so we delay processing the click */
            if (hw->z < para->finger_low) {
                hw->left = 0;
                goto out;
            }
            if (is_inside_rightbutton_area(para, hw->x, hw->y)) {
                hw->left = 0;
                hw->right = 1;
            }
            else if (is_inside_sec_rightbutton_area(para, hw->x, hw->y)) {
                hw->left = 0;
                hw->right = 1;
            }
            else if (is_inside_middlebutton_area(para, hw->x, hw->y)) {
                hw->left = 0;
                hw->middle = 1;
            }
            else if (is_inside_sec_middlebutton_area(para, hw->x, hw->y)) {
                hw->left = 0;
                hw->middle = 1;
            }
            priv->clickpad_click_millis = now;
        }
        else if (hw->left) {
            hw->left   = (priv->lastButtons & 1) ? 1 : 0;
            hw->middle = (priv->lastButtons & 2) ? 1 : 0;
            hw->right  = (priv->lastButtons & 4) ? 1 : 0;
        }
    }

    /* Fingers emulate other buttons. ClickFinger can only be
       triggered on transition, when left is pressed
     */
    if (hw->left && !(priv->lastButtons & 7) && hw->numFingers >= 1)
        handle_clickfinger(priv, hw);

out:
    /* Two finger emulation */
    if (hw->numFingers == 1 && hw->z >= para->emulate_twofinger_z &&
        hw->fingerWidth >= para->emulate_twofinger_w) {
        hw->numFingers = 2;
    }
}

static void
post_button_click(const InputInfoPtr pInfo, const int button)
{
    xf86PostButtonEvent(pInfo->dev, FALSE, button, TRUE, 0, 0);
    xf86PostButtonEvent(pInfo->dev, FALSE, button, FALSE, 0, 0);
}

static void
post_scroll_events(const InputInfoPtr pInfo)
{
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);

    valuator_mask_zero(priv->scroll_events_mask);

    if (priv->scroll.delta_y != 0.0) {
        valuator_mask_set_double(priv->scroll_events_mask,
                                 priv->scroll_axis_vert, priv->scroll.delta_y);
        priv->scroll.delta_y = 0;
    }
    if (priv->scroll.delta_x != 0.0) {
        valuator_mask_set_double(priv->scroll_events_mask,
                                 priv->scroll_axis_horiz, priv->scroll.delta_x);
        priv->scroll.delta_x = 0;
    }
    if (valuator_mask_num_valuators(priv->scroll_events_mask))
        xf86PostMotionEventM(pInfo->dev, FALSE, priv->scroll_events_mask);
}

static inline int
repeat_scrollbuttons(const InputInfoPtr pInfo,
                     const struct SynapticsHwState *hw,
                     int buttons, CARD32 now, int delay)
{
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
    SynapticsParameters *para = &priv->synpara;
    int repeat_delay;
    int rep_buttons = 0;

    if (para->updown_button_repeat)
        rep_buttons |= (1 << (4 - 1)) | (1 << (5 - 1));
    if (para->leftright_button_repeat)
        rep_buttons |= (1 << (6 - 1)) | (1 << (7 - 1));

    /* Handle auto repeat buttons */
    repeat_delay = clamp(para->scroll_button_repeat, SBR_MIN, SBR_MAX);
    if (((hw->up || hw->down) && para->updown_button_repeat &&
         para->updown_button_scrolling) ||
        ((hw->multi[2] || hw->multi[3]) && para->leftright_button_repeat &&
         para->leftright_button_scrolling)) {
        priv->repeatButtons = buttons & rep_buttons;
        if (!priv->nextRepeat) {
            priv->nextRepeat = now + repeat_delay * 2;
        }
    }
    else {
        priv->repeatButtons = 0;
        priv->nextRepeat = 0;
    }

    if (priv->repeatButtons) {
        int timeleft = TIME_DIFF(priv->nextRepeat, now);
        if (timeleft > 0)
            delay = MIN(delay, timeleft);
        if (timeleft <= 0) {
            int change;

            change = priv->repeatButtons;
            while (change) {
                int id = ffs(change);

                change &= ~(1 << (id - 1));
                if (id == 4)
                    priv->scroll.delta_y -= para->scroll_dist_vert;
                else if (id == 5)
                    priv->scroll.delta_y += para->scroll_dist_vert;
                else if (id == 6)
                    priv->scroll.delta_x -= para->scroll_dist_horiz;
                else if (id == 7)
                    priv->scroll.delta_x += para->scroll_dist_horiz;
            }

            priv->nextRepeat = now + repeat_delay;
            delay = MIN(delay, repeat_delay);
        }
    }

    return delay;
}

/* Update the open slots and number of active touches */
static void
UpdateTouchState(InputInfoPtr pInfo, struct SynapticsHwState *hw)
{
    SynapticsPrivate *priv = (SynapticsPrivate *) pInfo->private;

    for (int i = 0; i < hw->num_mt_mask; i++) {
        if (hw->slot_state[i] == SLOTSTATE_OPEN) {
            priv->open_slots[priv->num_active_touches] = i;
            priv->num_active_touches++;
            if (priv->num_active_touches > priv->num_slots) {
                ErrorFSigSafe("BUG: synaptics: more active touches (%d) than slots (%d)\n",
                    priv->num_active_touches,
                    priv->num_slots);
                xorg_backtrace();
            }
        }
        else if (hw->slot_state[i] == SLOTSTATE_CLOSE) {
            Bool found = FALSE;

            for (int j = 0; j < priv->num_active_touches - 1; j++) {
                if (priv->open_slots[j] == i)
                    found = TRUE;

                if (found)
                    priv->open_slots[j] = priv->open_slots[j + 1];
            }

            if (priv->num_active_touches == 0) {
                ErrorFSigSafe("BUG: synaptics: no active touches where there should be at least one\n");
                xorg_backtrace();
            }

            if (priv->num_active_touches > 0)
                priv->num_active_touches--;
        }
    }

    SynapticsResetTouchHwState(hw, FALSE);
}

static void
filter_jitter(SynapticsPrivate * priv, int *x, int *y)
{
    SynapticsParameters *para = &priv->synpara;

    priv->hyst_center_x = hysteresis(*x, priv->hyst_center_x, para->hyst_x);
    priv->hyst_center_y = hysteresis(*y, priv->hyst_center_y, para->hyst_y);
    *x = priv->hyst_center_x;
    *y = priv->hyst_center_y;
}

static void
reset_hw_state(struct SynapticsHwState *hw)
{
    hw->x = 0;
    hw->y = 0;
    hw->z = 0;
    hw->numFingers = 0;
    hw->fingerWidth = 0;
}

/*
 * React on changes in the hardware state. This function is called every time
 * the hardware state changes. The return value is used to specify how many
 * milliseconds to wait before calling the function again if no state change
 * occurs.
 *
 * from_timer denotes if HandleState was triggered from a timer (e.g. to
 * generate fake motion events, or for the tap-to-click state machine), rather
 * than from having received a motion event.
 */
static int
HandleState(InputInfoPtr pInfo, struct SynapticsHwState *hw, CARD32 now,
            Bool from_timer)
{
    SynapticsPrivate *priv = (SynapticsPrivate *) (pInfo->private);
    SynapticsParameters *para = &priv->synpara;
    enum FingerState finger = FS_UNTOUCHED;
    int dx = 0, dy = 0, buttons;
    enum EdgeType edge = NO_EDGE;
    int change;
    int double_click = FALSE;
    int delay = 1000000000;
    int timeleft;
    Bool inside_active_area;
    Bool using_cumulative_coords = FALSE;
    Bool ignore_motion;

    /* We need both and x/y, the driver can't handle just one of the two
     * yet. But since it's possible to hit a phys button on non-clickpads
     * without ever getting motion data first, we must continue with 0/0 for
     * that case. */
    if (hw->x == INT_MIN || hw->y == INT_MAX) {
        if (para->clickpad)
            return delay;
        else if (hw->left || hw->right || hw->middle) {
            hw->x = (hw->x == INT_MIN) ? 0 : hw->x;
            hw->y = (hw->y == INT_MIN) ? 0 : hw->y;
        }
    }

    /* If a physical button is pressed on a clickpad or a two-finger scrolling
     * is ongoing, use cumulative relative touch movements for motion */
    if (para->clickpad &&
        ((priv->lastButtons & 7) ||
        (priv->vert_scroll_twofinger_on || priv->horiz_scroll_twofinger_on)) &&
        priv->last_button_area != TOP_BUTTON_AREA) {
        hw->x = hw->cumulative_dx;
        hw->y = hw->cumulative_dy;
        using_cumulative_coords = TRUE;
    }

    /* apply hysteresis before doing anything serious. This cancels
     * out a lot of noise which might surface in strange phenomena
     * like flicker in scrolling or noise motion. */
    filter_jitter(priv, &hw->x, &hw->y);

    inside_active_area = is_inside_active_area(priv, hw->x, hw->y);

    /* Ignore motion *starting* inside softbuttonareas */
    if (priv->finger_state < FS_TOUCHED)
        priv->last_button_area = current_button_area(para, hw->x, hw->y);
    /* If we already have a finger down, clear last_button_area if it goes
       outside of the softbuttonareas */
    else if (priv->last_button_area != NO_BUTTON_AREA &&
             current_button_area(para, hw->x, hw->y) == NO_BUTTON_AREA)
        priv->last_button_area = NO_BUTTON_AREA;

    ignore_motion = para->touchpad_off == TOUCHPAD_OFF ||
        (!using_cumulative_coords && priv->last_button_area != NO_BUTTON_AREA);

    /* these two just update hw->left, right, etc. */
    update_hw_button_state(pInfo, hw, now, &delay);
    if (priv->has_scrollbuttons)
        double_click = adjust_state_from_scrollbuttons(pInfo, hw);

    /* Ignore motion the first X ms after a clickpad click */
    if (priv->clickpad_click_millis) {
        if(TIME_DIFF(priv->clickpad_click_millis +
                     para->clickpad_ignore_motion_time, now) > 0)
            ignore_motion = TRUE;
        else
            priv->clickpad_click_millis = 0;
    }

    /* now we know that these _coordinates_ aren't in the area.
       invalid are: x, y, z, numFingers, fingerWidth
       valid are: millis, left/right/middle/up/down/etc.
     */
    if (!inside_active_area)
        reset_hw_state(hw);

    /* no edge or finger detection outside of area */
    if (inside_active_area) {
        edge = edge_detection(priv, hw->x, hw->y);
        if (!from_timer)
            finger = SynapticsDetectFinger(priv, hw);
        else
            finger = priv->finger_state;
    }

    /* tap and drag detection. Needs to be performed even if the finger is in
     * the dead area to reset the state. */
    timeleft = HandleTapProcessing(priv, hw, now, finger, inside_active_area);
    if (timeleft > 0)
        delay = MIN(delay, timeleft);

    if (inside_active_area) {
        /* Don't bother about scrolling in the dead area of the touchpad. */
        timeleft = HandleScrolling(priv, hw, edge, (finger >= FS_TOUCHED));
        if (timeleft > 0)
            delay = MIN(delay, timeleft);

        /*
         * Compensate for unequal x/y resolution. This needs to be done after
         * calculations that require unadjusted coordinates, for example edge
         * detection.
         */
    }

    dx = dy = 0;

    timeleft = ComputeDeltas(priv, hw, edge, &dx, &dy, inside_active_area);
    delay = MIN(delay, timeleft);

    buttons = ((hw->left ? 0x01 : 0) |
               (hw->middle ? 0x02 : 0) |
               (hw->right ? 0x04 : 0) |
               (hw->up ? 0x08 : 0) |
               (hw->down ? 0x10 : 0) |
               (hw->multi[2] ? 0x20 : 0) | (hw->multi[3] ? 0x40 : 0));

    if (priv->tap_button > 0 && priv->tap_button_state == TBS_BUTTON_DOWN)
        buttons |= 1 << (priv->tap_button - 1);

    /* Post events */
    if (finger >= FS_TOUCHED && (dx || dy) && !ignore_motion)
        xf86PostMotionEvent(pInfo->dev, 0, 0, 2, dx, dy);

    if (priv->mid_emu_state == MBE_LEFT_CLICK) {
        post_button_click(pInfo, 1);
        priv->mid_emu_state = MBE_OFF;
    }
    else if (priv->mid_emu_state == MBE_RIGHT_CLICK) {
        post_button_click(pInfo, 3);
        priv->mid_emu_state = MBE_OFF;
    }

    change = buttons ^ priv->lastButtons;
    while (change) {
        int id = ffs(change);   /* number of first set bit 1..32 is returned */
        change &= ~(1 << (id - 1));
        xf86PostButtonEvent(pInfo->dev, FALSE, id, (buttons & (1 << (id - 1))),
                            0, 0);
    }

    if (priv->has_scrollbuttons)
        delay = repeat_scrollbuttons(pInfo, hw, buttons, now, delay);

    /* Process scroll events only if coordinates are
     * in the Synaptics Area
     */
    if (inside_active_area &&
        (priv->scroll.delta_x != 0.0 || priv->scroll.delta_y != 0.0)) {
        post_scroll_events(pInfo);
        priv->scroll.last_millis = hw->millis;
    }

    if (double_click) {
        post_button_click(pInfo, 1);
        post_button_click(pInfo, 1);
    }

    UpdateTouchState(pInfo, hw);

    /* Save old values of some state variables */
    priv->finger_state = finger;
    priv->lastButtons = buttons;

    /* generate a history of the absolute positions */
    if (inside_active_area)
        store_history(priv, hw->x, hw->y, hw->millis);

    return delay;
}

static int
ControlProc(InputInfoPtr pInfo, xDeviceCtl * control)
{
    DBG(3, "Control Proc called\n");
    return Success;
}

static int
SwitchMode(ClientPtr client, DeviceIntPtr dev, int mode)
{
    DBG(3, "SwitchMode called\n");

    return XI_BadMode;
}

static void
ReadDevDimensions(InputInfoPtr pInfo)
{
    SynapticsPrivate *priv = (SynapticsPrivate *) pInfo->private;

    if (priv->proto_ops->ReadDevDimensions)
        priv->proto_ops->ReadDevDimensions(pInfo);

    SanitizeDimensions(pInfo);
}

static Bool
QueryHardware(InputInfoPtr pInfo)
{
    SynapticsPrivate *priv = (SynapticsPrivate *) pInfo->private;

    priv->comm.protoBufTail = 0;

    if (!priv->proto_ops->QueryHardware(pInfo)) {
        xf86IDrvMsg(pInfo, X_PROBED, "no supported touchpad found\n");
        if (priv->proto_ops->DeviceOffHook)
            priv->proto_ops->DeviceOffHook(pInfo);
        return FALSE;
    }

    return TRUE;
}
