// SPDX-License-Identifier: GPL-2.0-only
/*
 * ALPS touchpad PS/2 mouse driver
 *
 * Copyright (c) 2003 Neil Brown <neilb@cse.unsw.edu.au>
 * Copyright (c) 2003-2005 Peter Osterlund <petero2@telia.com>
 * Copyright (c) 2004 Dmitry Torokhov <dtor@mail.ru>
 * Copyright (c) 2005 Vojtech Pavlik <vojtech@suse.cz>
 * Copyright (c) 2009 Sebastian Kapfer <sebastian_kapfer@gmx.net>
 *
 * ALPS detection, tap switching and status querying info is taken from
 * tpconfig utility (by C. Scott Ananian and Bruce Kall).
 */

#include <linux/slab.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/serio.h>
#include <linux/libps2.h>
#include <linux/dmi.h>

#include "psmouse.h"
#include "alps.h"
#include "trackpoint.h"

/*
 * Definitions for ALPS version 3 and 4 command mode protocol
 */
#define ALPS_CMD_NIBBLE_10      0x01f2

#define ALPS_REG_BASE_RUSHMORE  0xc2c0
#define ALPS_REG_BASE_V7        0xc2c0
#define ALPS_REG_BASE_PINNACLE  0x0000

static const struct alps_nibble_commands alps_v3_nibble_commands[] = {
        { PSMOUSE_CMD_SETPOLL,          0x00 }, /* 0 */
        { PSMOUSE_CMD_RESET_DIS,        0x00 }, /* 1 */
        { PSMOUSE_CMD_SETSCALE21,       0x00 }, /* 2 */
        { PSMOUSE_CMD_SETRATE,          0x0a }, /* 3 */
        { PSMOUSE_CMD_SETRATE,          0x14 }, /* 4 */
        { PSMOUSE_CMD_SETRATE,          0x28 }, /* 5 */
        { PSMOUSE_CMD_SETRATE,          0x3c }, /* 6 */
        { PSMOUSE_CMD_SETRATE,          0x50 }, /* 7 */
        { PSMOUSE_CMD_SETRATE,          0x64 }, /* 8 */
        { PSMOUSE_CMD_SETRATE,          0xc8 }, /* 9 */
        { ALPS_CMD_NIBBLE_10,           0x00 }, /* a */
        { PSMOUSE_CMD_SETRES,           0x00 }, /* b */
        { PSMOUSE_CMD_SETRES,           0x01 }, /* c */
        { PSMOUSE_CMD_SETRES,           0x02 }, /* d */
        { PSMOUSE_CMD_SETRES,           0x03 }, /* e */
        { PSMOUSE_CMD_SETSCALE11,       0x00 }, /* f */
};

static const struct alps_nibble_commands alps_v4_nibble_commands[] = {
        { PSMOUSE_CMD_ENABLE,           0x00 }, /* 0 */
        { PSMOUSE_CMD_RESET_DIS,        0x00 }, /* 1 */
        { PSMOUSE_CMD_SETSCALE21,       0x00 }, /* 2 */
        { PSMOUSE_CMD_SETRATE,          0x0a }, /* 3 */
        { PSMOUSE_CMD_SETRATE,          0x14 }, /* 4 */
        { PSMOUSE_CMD_SETRATE,          0x28 }, /* 5 */
        { PSMOUSE_CMD_SETRATE,          0x3c }, /* 6 */
        { PSMOUSE_CMD_SETRATE,          0x50 }, /* 7 */
        { PSMOUSE_CMD_SETRATE,          0x64 }, /* 8 */
        { PSMOUSE_CMD_SETRATE,          0xc8 }, /* 9 */
        { ALPS_CMD_NIBBLE_10,           0x00 }, /* a */
        { PSMOUSE_CMD_SETRES,           0x00 }, /* b */
        { PSMOUSE_CMD_SETRES,           0x01 }, /* c */
        { PSMOUSE_CMD_SETRES,           0x02 }, /* d */
        { PSMOUSE_CMD_SETRES,           0x03 }, /* e */
        { PSMOUSE_CMD_SETSCALE11,       0x00 }, /* f */
};

static const struct alps_nibble_commands alps_v6_nibble_commands[] = {
        { PSMOUSE_CMD_ENABLE,           0x00 }, /* 0 */
        { PSMOUSE_CMD_SETRATE,          0x0a }, /* 1 */
        { PSMOUSE_CMD_SETRATE,          0x14 }, /* 2 */
        { PSMOUSE_CMD_SETRATE,          0x28 }, /* 3 */
        { PSMOUSE_CMD_SETRATE,          0x3c }, /* 4 */
        { PSMOUSE_CMD_SETRATE,          0x50 }, /* 5 */
        { PSMOUSE_CMD_SETRATE,          0x64 }, /* 6 */
        { PSMOUSE_CMD_SETRATE,          0xc8 }, /* 7 */
        { PSMOUSE_CMD_GETID,            0x00 }, /* 8 */
        { PSMOUSE_CMD_GETINFO,          0x00 }, /* 9 */
        { PSMOUSE_CMD_SETRES,           0x00 }, /* a */
        { PSMOUSE_CMD_SETRES,           0x01 }, /* b */
        { PSMOUSE_CMD_SETRES,           0x02 }, /* c */
        { PSMOUSE_CMD_SETRES,           0x03 }, /* d */
        { PSMOUSE_CMD_SETSCALE21,       0x00 }, /* e */
        { PSMOUSE_CMD_SETSCALE11,       0x00 }, /* f */
};


#define ALPS_DUALPOINT          0x02    /* touchpad has trackstick */
#define ALPS_PASS               0x04    /* device has a pass-through port */

#define ALPS_WHEEL              0x08    /* hardware wheel present */
#define ALPS_FW_BK_1            0x10    /* front & back buttons present */
#define ALPS_FW_BK_2            0x20    /* front & back buttons present */
#define ALPS_FOUR_BUTTONS       0x40    /* 4 direction button present */
#define ALPS_PS2_INTERLEAVED    0x80    /* 3-byte PS/2 packet interleaved with
                                           6-byte ALPS packet */
#define ALPS_STICK_BITS         0x100   /* separate stick button bits */
#define ALPS_BUTTONPAD          0x200   /* device is a clickpad */
#define ALPS_DUALPOINT_WITH_PRESSURE    0x400   /* device can report trackpoint pressure */

static const struct alps_model_info alps_model_data[] = {
        /*
         * XXX This entry is suspicious. First byte has zero lower nibble,
         * which is what a normal mouse would report. Also, the value 0x0e
         * isn't valid per PS/2 spec.
         */
        { { 0x20, 0x02, 0x0e }, { ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT } },

        { { 0x22, 0x02, 0x0a }, { ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT } },
        { { 0x22, 0x02, 0x14 }, { ALPS_PROTO_V2, 0xff, 0xff, ALPS_PASS | ALPS_DUALPOINT } },    /* Dell Latitude D600 */
        { { 0x32, 0x02, 0x14 }, { ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT } },    /* Toshiba Salellite Pro M10 */
        { { 0x33, 0x02, 0x0a }, { ALPS_PROTO_V1, 0x88, 0xf8, 0 } },                             /* UMAX-530T */
        { { 0x52, 0x01, 0x14 }, { ALPS_PROTO_V2, 0xff, 0xff,
                ALPS_PASS | ALPS_DUALPOINT | ALPS_PS2_INTERLEAVED } },                          /* Toshiba Tecra A11-11L */
        { { 0x53, 0x02, 0x0a }, { ALPS_PROTO_V2, 0xf8, 0xf8, 0 } },
        { { 0x53, 0x02, 0x14 }, { ALPS_PROTO_V2, 0xf8, 0xf8, 0 } },
        { { 0x60, 0x03, 0xc8 }, { ALPS_PROTO_V2, 0xf8, 0xf8, 0 } },                             /* HP ze1115 */
        { { 0x62, 0x02, 0x14 }, { ALPS_PROTO_V2, 0xcf, 0xcf,
                ALPS_PASS | ALPS_DUALPOINT | ALPS_PS2_INTERLEAVED } },                          /* Dell Latitude E5500, E6400, E6500, Precision M4400 */
        { { 0x63, 0x02, 0x0a }, { ALPS_PROTO_V2, 0xf8, 0xf8, 0 } },
        { { 0x63, 0x02, 0x14 }, { ALPS_PROTO_V2, 0xf8, 0xf8, 0 } },
        { { 0x63, 0x02, 0x28 }, { ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_FW_BK_2 } },                  /* Fujitsu Siemens S6010 */
        { { 0x63, 0x02, 0x3c }, { ALPS_PROTO_V2, 0x8f, 0x8f, ALPS_WHEEL } },                    /* Toshiba Satellite S2400-103 */
        { { 0x63, 0x02, 0x50 }, { ALPS_PROTO_V2, 0xef, 0xef, ALPS_FW_BK_1 } },                  /* NEC Versa L320 */
        { { 0x63, 0x02, 0x64 }, { ALPS_PROTO_V2, 0xf8, 0xf8, 0 } },
        { { 0x63, 0x03, 0xc8 }, { ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT } },    /* Dell Latitude D800 */
        { { 0x73, 0x00, 0x0a }, { ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_DUALPOINT } },                /* ThinkPad R61 8918-5QG */
        { { 0x73, 0x00, 0x14 }, { ALPS_PROTO_V6, 0xff, 0xff, ALPS_DUALPOINT } },                /* Dell XT2 */
        { { 0x73, 0x02, 0x0a }, { ALPS_PROTO_V2, 0xf8, 0xf8, 0 } },
        { { 0x73, 0x02, 0x14 }, { ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_FW_BK_2 } },                  /* Ahtec Laptop */
        { { 0x73, 0x02, 0x50 }, { ALPS_PROTO_V2, 0xcf, 0xcf, ALPS_FOUR_BUTTONS } },             /* Dell Vostro 1400 */
};

static const struct alps_protocol_info alps_v3_protocol_data = {
        ALPS_PROTO_V3, 0x8f, 0x8f, ALPS_DUALPOINT | ALPS_DUALPOINT_WITH_PRESSURE
};

static const struct alps_protocol_info alps_v3_rushmore_data = {
        ALPS_PROTO_V3_RUSHMORE, 0x8f, 0x8f, ALPS_DUALPOINT | ALPS_DUALPOINT_WITH_PRESSURE
};

static const struct alps_protocol_info alps_v4_protocol_data = {
        ALPS_PROTO_V4, 0x8f, 0x8f, 0
};

static const struct alps_protocol_info alps_v5_protocol_data = {
        ALPS_PROTO_V5, 0xc8, 0xd8, 0
};

static const struct alps_protocol_info alps_v7_protocol_data = {
        ALPS_PROTO_V7, 0x48, 0x48, ALPS_DUALPOINT | ALPS_DUALPOINT_WITH_PRESSURE
};

static const struct alps_protocol_info alps_v8_protocol_data = {
        ALPS_PROTO_V8, 0x18, 0x18, 0
};

static const struct alps_protocol_info alps_v9_protocol_data = {
        ALPS_PROTO_V9, 0xc8, 0xc8, 0
};

/*
 * Some v2 models report the stick buttons in separate bits
 */
static const struct dmi_system_id alps_dmi_has_separate_stick_buttons[] = {
#if defined(CONFIG_DMI) && defined(CONFIG_X86)
        {
                /* Extrapolated from other entries */
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D420"),
                },
        },
        {
                /* Reported-by: Hans de Bruin <jmdebruin@xmsnet.nl> */
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D430"),
                },
        },
        {
                /* Reported-by: Hans de Goede <hdegoede@redhat.com> */
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D620"),
                },
        },
        {
                /* Extrapolated from other entries */
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D630"),
                },
        },
#endif
        { }
};

static void alps_set_abs_params_st(struct alps_data *priv,
                                   struct input_dev *dev1);
static void alps_set_abs_params_semi_mt(struct alps_data *priv,
                                        struct input_dev *dev1);
static void alps_set_abs_params_v7(struct alps_data *priv,
                                   struct input_dev *dev1);
static void alps_set_abs_params_ss4_v2(struct alps_data *priv,
                                       struct input_dev *dev1);

/* Packet formats are described in Documentation/input/devices/alps.rst */

static bool alps_is_valid_first_byte(struct alps_data *priv,
                                     unsigned char data)
{
        return (data & priv->mask0) == priv->byte0;
}

static void alps_report_buttons(struct input_dev *dev1, struct input_dev *dev2,
                                int left, int right, int middle)
{
        struct input_dev *dev;

        /*
         * If shared button has already been reported on the
         * other device (dev2) then this event should be also
         * sent through that device.
         */
        dev = (dev2 && test_bit(BTN_LEFT, dev2->key)) ? dev2 : dev1;
        input_report_key(dev, BTN_LEFT, left);

        dev = (dev2 && test_bit(BTN_RIGHT, dev2->key)) ? dev2 : dev1;
        input_report_key(dev, BTN_RIGHT, right);

        dev = (dev2 && test_bit(BTN_MIDDLE, dev2->key)) ? dev2 : dev1;
        input_report_key(dev, BTN_MIDDLE, middle);

        /*
         * Sync the _other_ device now, we'll do the first
         * device later once we report the rest of the events.
         */
        if (dev2)
                input_sync(dev2);
}

static void alps_process_packet_v1_v2(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        unsigned char *packet = psmouse->packet;
        struct input_dev *dev = psmouse->dev;
        struct input_dev *dev2 = priv->dev2;
        int x, y, z, ges, fin, left, right, middle;
        int back = 0, forward = 0;

        if (priv->proto_version == ALPS_PROTO_V1) {
                left = packet[2] & 0x10;
                right = packet[2] & 0x08;
                middle = 0;
                x = packet[1] | ((packet[0] & 0x07) << 7);
                y = packet[4] | ((packet[3] & 0x07) << 7);
                z = packet[5];
        } else {
                left = packet[3] & 1;
                right = packet[3] & 2;
                middle = packet[3] & 4;
                x = packet[1] | ((packet[2] & 0x78) << (7 - 3));
                y = packet[4] | ((packet[3] & 0x70) << (7 - 4));
                z = packet[5];
        }

        if (priv->flags & ALPS_FW_BK_1) {
                back = packet[0] & 0x10;
                forward = packet[2] & 4;
        }

        if (priv->flags & ALPS_FW_BK_2) {
                back = packet[3] & 4;
                forward = packet[2] & 4;
                if ((middle = forward && back))
                        forward = back = 0;
        }

        ges = packet[2] & 1;
        fin = packet[2] & 2;

        if ((priv->flags & ALPS_DUALPOINT) && z == 127) {
                input_report_rel(dev2, REL_X,  (x > 383 ? (x - 768) : x));
                input_report_rel(dev2, REL_Y, -(y > 255 ? (y - 512) : y));

                alps_report_buttons(dev2, dev, left, right, middle);

                input_sync(dev2);
                return;
        }

        /* Some models have separate stick button bits */
        if (priv->flags & ALPS_STICK_BITS) {
                left |= packet[0] & 1;
                right |= packet[0] & 2;
                middle |= packet[0] & 4;
        }

        alps_report_buttons(dev, dev2, left, right, middle);

        /* Convert hardware tap to a reasonable Z value */
        if (ges && !fin)
                z = 40;

        /*
         * A "tap and drag" operation is reported by the hardware as a transition
         * from (!fin && ges) to (fin && ges). This should be translated to the
         * sequence Z>0, Z==0, Z>0, so the Z==0 event has to be generated manually.
         */
        if (ges && fin && !priv->prev_fin) {
                input_report_abs(dev, ABS_X, x);
                input_report_abs(dev, ABS_Y, y);
                input_report_abs(dev, ABS_PRESSURE, 0);
                input_report_key(dev, BTN_TOOL_FINGER, 0);
                input_sync(dev);
        }
        priv->prev_fin = fin;

        if (z > 30)
                input_report_key(dev, BTN_TOUCH, 1);
        if (z < 25)
                input_report_key(dev, BTN_TOUCH, 0);

        if (z > 0) {
                input_report_abs(dev, ABS_X, x);
                input_report_abs(dev, ABS_Y, y);
        }

        input_report_abs(dev, ABS_PRESSURE, z);
        input_report_key(dev, BTN_TOOL_FINGER, z > 0);

        if (priv->flags & ALPS_WHEEL)
                input_report_rel(dev, REL_WHEEL, ((packet[2] << 1) & 0x08) - ((packet[0] >> 4) & 0x07));

        if (priv->flags & (ALPS_FW_BK_1 | ALPS_FW_BK_2)) {
                input_report_key(dev, BTN_FORWARD, forward);
                input_report_key(dev, BTN_BACK, back);
        }

        if (priv->flags & ALPS_FOUR_BUTTONS) {
                input_report_key(dev, BTN_0, packet[2] & 4);
                input_report_key(dev, BTN_1, packet[0] & 0x10);
                input_report_key(dev, BTN_2, packet[3] & 4);
                input_report_key(dev, BTN_3, packet[0] & 0x20);
        }

        input_sync(dev);
}

static void alps_get_bitmap_points(unsigned int map,
                                   struct alps_bitmap_point *low,
                                   struct alps_bitmap_point *high,
                                   int *fingers)
{
        struct alps_bitmap_point *point;
        int i, bit, prev_bit = 0;

        point = low;
        for (i = 0; map != 0; i++, map >>= 1) {
                bit = map & 1;
                if (bit) {
                        if (!prev_bit) {
                                point->start_bit = i;
                                point->num_bits = 0;
                                (*fingers)++;
                        }
                        point->num_bits++;
                } else {
                        if (prev_bit)
                                point = high;
                }
                prev_bit = bit;
        }
}

/*
 * Process bitmap data from semi-mt protocols. Returns the number of
 * fingers detected. A return value of 0 means at least one of the
 * bitmaps was empty.
 *
 * The bitmaps don't have enough data to track fingers, so this function
 * only generates points representing a bounding box of all contacts.
 * These points are returned in fields->mt when the return value
 * is greater than 0.
 */
static int alps_process_bitmap(struct alps_data *priv,
                               struct alps_fields *fields)
{
        int i, fingers_x = 0, fingers_y = 0, fingers, closest;
        struct alps_bitmap_point x_low = {0,}, x_high = {0,};
        struct alps_bitmap_point y_low = {0,}, y_high = {0,};
        struct input_mt_pos corner[4];

        if (!fields->x_map || !fields->y_map)
                return 0;

        alps_get_bitmap_points(fields->x_map, &x_low, &x_high, &fingers_x);
        alps_get_bitmap_points(fields->y_map, &y_low, &y_high, &fingers_y);

        /*
         * Fingers can overlap, so we use the maximum count of fingers
         * on either axis as the finger count.
         */
        fingers = max(fingers_x, fingers_y);

        /*
         * If an axis reports only a single contact, we have overlapping or
         * adjacent fingers. Divide the single contact between the two points.
         */
        if (fingers_x == 1) {
                i = (x_low.num_bits - 1) / 2;
                x_low.num_bits = x_low.num_bits - i;
                x_high.start_bit = x_low.start_bit + i;
                x_high.num_bits = max(i, 1);
        }
        if (fingers_y == 1) {
                i = (y_low.num_bits - 1) / 2;
                y_low.num_bits = y_low.num_bits - i;
                y_high.start_bit = y_low.start_bit + i;
                y_high.num_bits = max(i, 1);
        }

        /* top-left corner */
        corner[0].x =
                (priv->x_max * (2 * x_low.start_bit + x_low.num_bits - 1)) /
                (2 * (priv->x_bits - 1));
        corner[0].y =
                (priv->y_max * (2 * y_low.start_bit + y_low.num_bits - 1)) /
                (2 * (priv->y_bits - 1));

        /* top-right corner */
        corner[1].x =
                (priv->x_max * (2 * x_high.start_bit + x_high.num_bits - 1)) /
                (2 * (priv->x_bits - 1));
        corner[1].y =
                (priv->y_max * (2 * y_low.start_bit + y_low.num_bits - 1)) /
                (2 * (priv->y_bits - 1));

        /* bottom-right corner */
        corner[2].x =
                (priv->x_max * (2 * x_high.start_bit + x_high.num_bits - 1)) /
                (2 * (priv->x_bits - 1));
        corner[2].y =
                (priv->y_max * (2 * y_high.start_bit + y_high.num_bits - 1)) /
                (2 * (priv->y_bits - 1));

        /* bottom-left corner */
        corner[3].x =
                (priv->x_max * (2 * x_low.start_bit + x_low.num_bits - 1)) /
                (2 * (priv->x_bits - 1));
        corner[3].y =
                (priv->y_max * (2 * y_high.start_bit + y_high.num_bits - 1)) /
                (2 * (priv->y_bits - 1));

        /* x-bitmap order is reversed on v5 touchpads  */
        if (priv->proto_version == ALPS_PROTO_V5) {
                for (i = 0; i < 4; i++)
                        corner[i].x = priv->x_max - corner[i].x;
        }

        /* y-bitmap order is reversed on v3 and v4 touchpads  */
        if (priv->proto_version == ALPS_PROTO_V3 ||
            priv->proto_version == ALPS_PROTO_V4) {
                for (i = 0; i < 4; i++)
                        corner[i].y = priv->y_max - corner[i].y;
        }

        /*
         * We only select a corner for the second touch once per 2 finger
         * touch sequence to avoid the chosen corner (and thus the coordinates)
         * jumping around when the first touch is in the middle.
         */
        if (priv->second_touch == -1) {
                /* Find corner closest to our st coordinates */
                closest = 0x7fffffff;
                for (i = 0; i < 4; i++) {
                        int dx = fields->st.x - corner[i].x;
                        int dy = fields->st.y - corner[i].y;
                        int distance = dx * dx + dy * dy;

                        if (distance < closest) {
                                priv->second_touch = i;
                                closest = distance;
                        }
                }
                /* And select the opposite corner to use for the 2nd touch */
                priv->second_touch = (priv->second_touch + 2) % 4;
        }

        fields->mt[0] = fields->st;
        fields->mt[1] = corner[priv->second_touch];

        return fingers;
}

static void alps_set_slot(struct input_dev *dev, int slot, int x, int y)
{
        input_mt_slot(dev, slot);
        input_mt_report_slot_state(dev, MT_TOOL_FINGER, true);
        input_report_abs(dev, ABS_MT_POSITION_X, x);
        input_report_abs(dev, ABS_MT_POSITION_Y, y);
}

static void alps_report_mt_data(struct psmouse *psmouse, int n)
{
        struct alps_data *priv = psmouse->private;
        struct input_dev *dev = psmouse->dev;
        struct alps_fields *f = &priv->f;
        int i, slot[MAX_TOUCHES];

        input_mt_assign_slots(dev, slot, f->mt, n, 0);
        for (i = 0; i < n; i++)
                alps_set_slot(dev, slot[i], f->mt[i].x, f->mt[i].y);

        input_mt_sync_frame(dev);
}

static void alps_report_semi_mt_data(struct psmouse *psmouse, int fingers)
{
        struct alps_data *priv = psmouse->private;
        struct input_dev *dev = psmouse->dev;
        struct alps_fields *f = &priv->f;

        /* Use st data when we don't have mt data */
        if (fingers < 2) {
                f->mt[0].x = f->st.x;
                f->mt[0].y = f->st.y;
                fingers = f->pressure > 0 ? 1 : 0;
                priv->second_touch = -1;
        }

        if (fingers >= 1)
                alps_set_slot(dev, 0, f->mt[0].x, f->mt[0].y);
        if (fingers >= 2)
                alps_set_slot(dev, 1, f->mt[1].x, f->mt[1].y);
        input_mt_sync_frame(dev);

        input_mt_report_finger_count(dev, fingers);

        input_report_key(dev, BTN_LEFT, f->left);
        input_report_key(dev, BTN_RIGHT, f->right);
        input_report_key(dev, BTN_MIDDLE, f->middle);

        input_report_abs(dev, ABS_PRESSURE, f->pressure);

        input_sync(dev);
}

static void alps_process_trackstick_packet_v3(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        unsigned char *packet = psmouse->packet;
        struct input_dev *dev = priv->dev2;
        int x, y, z, left, right, middle;

        /* It should be a DualPoint when received trackstick packet */
        if (!(priv->flags & ALPS_DUALPOINT)) {
                psmouse_warn(psmouse,
                             "Rejected trackstick packet from non DualPoint device");
                return;
        }

        /* Sanity check packet */
        if (!(packet[0] & 0x40)) {
                psmouse_dbg(psmouse, "Bad trackstick packet, discarding\n");
                return;
        }

        /*
         * There's a special packet that seems to indicate the end
         * of a stream of trackstick data. Filter these out.
         */
        if (packet[1] == 0x7f && packet[2] == 0x7f && packet[4] == 0x7f)
                return;

        x = (s8)(((packet[0] & 0x20) << 2) | (packet[1] & 0x7f));
        y = (s8)(((packet[0] & 0x10) << 3) | (packet[2] & 0x7f));
        z = packet[4] & 0x7f;

        /*
         * The x and y values tend to be quite large, and when used
         * alone the trackstick is difficult to use. Scale them down
         * to compensate.
         */
        x /= 8;
        y /= 8;

        input_report_rel(dev, REL_X, x);
        input_report_rel(dev, REL_Y, -y);
        input_report_abs(dev, ABS_PRESSURE, z);

        /*
         * Most ALPS models report the trackstick buttons in the touchpad
         * packets, but a few report them here. No reliable way has been
         * found to differentiate between the models upfront, so we enable
         * the quirk in response to seeing a button press in the trackstick
         * packet.
         */
        left = packet[3] & 0x01;
        right = packet[3] & 0x02;
        middle = packet[3] & 0x04;

        if (!(priv->quirks & ALPS_QUIRK_TRACKSTICK_BUTTONS) &&
            (left || right || middle))
                priv->quirks |= ALPS_QUIRK_TRACKSTICK_BUTTONS;

        if (priv->quirks & ALPS_QUIRK_TRACKSTICK_BUTTONS) {
                input_report_key(dev, BTN_LEFT, left);
                input_report_key(dev, BTN_RIGHT, right);
                input_report_key(dev, BTN_MIDDLE, middle);
        }

        input_sync(dev);
        return;
}

static void alps_decode_buttons_v3(struct alps_fields *f, unsigned char *p)
{
        f->left = !!(p[3] & 0x01);
        f->right = !!(p[3] & 0x02);
        f->middle = !!(p[3] & 0x04);

        f->ts_left = !!(p[3] & 0x10);
        f->ts_right = !!(p[3] & 0x20);
        f->ts_middle = !!(p[3] & 0x40);
}

static int alps_decode_pinnacle(struct alps_fields *f, unsigned char *p,
                                 struct psmouse *psmouse)
{
        f->first_mp = !!(p[4] & 0x40);
        f->is_mp = !!(p[0] & 0x40);

        if (f->is_mp) {
                f->fingers = (p[5] & 0x3) + 1;
                f->x_map = ((p[4] & 0x7e) << 8) |
                           ((p[1] & 0x7f) << 2) |
                           ((p[0] & 0x30) >> 4);
                f->y_map = ((p[3] & 0x70) << 4) |
                           ((p[2] & 0x7f) << 1) |
                           (p[4] & 0x01);
        } else {
                f->st.x = ((p[1] & 0x7f) << 4) | ((p[4] & 0x30) >> 2) |
                       ((p[0] & 0x30) >> 4);
                f->st.y = ((p[2] & 0x7f) << 4) | (p[4] & 0x0f);
                f->pressure = p[5] & 0x7f;

                alps_decode_buttons_v3(f, p);
        }

        return 0;
}

static int alps_decode_rushmore(struct alps_fields *f, unsigned char *p,
                                 struct psmouse *psmouse)
{
        f->first_mp = !!(p[4] & 0x40);
        f->is_mp = !!(p[5] & 0x40);

        if (f->is_mp) {
                f->fingers = max((p[5] & 0x3), ((p[5] >> 2) & 0x3)) + 1;
                f->x_map = ((p[5] & 0x10) << 11) |
                           ((p[4] & 0x7e) << 8) |
                           ((p[1] & 0x7f) << 2) |
                           ((p[0] & 0x30) >> 4);
                f->y_map = ((p[5] & 0x20) << 6) |
                           ((p[3] & 0x70) << 4) |
                           ((p[2] & 0x7f) << 1) |
                           (p[4] & 0x01);
        } else {
                f->st.x = ((p[1] & 0x7f) << 4) | ((p[4] & 0x30) >> 2) |
                       ((p[0] & 0x30) >> 4);
                f->st.y = ((p[2] & 0x7f) << 4) | (p[4] & 0x0f);
                f->pressure = p[5] & 0x7f;

                alps_decode_buttons_v3(f, p);
        }

        return 0;
}

static int alps_decode_dolphin(struct alps_fields *f, unsigned char *p,
                                struct psmouse *psmouse)
{
        u64 palm_data = 0;
        struct alps_data *priv = psmouse->private;

        f->first_mp = !!(p[0] & 0x02);
        f->is_mp = !!(p[0] & 0x20);

        if (!f->is_mp) {
                f->st.x = ((p[1] & 0x7f) | ((p[4] & 0x0f) << 7));
                f->st.y = ((p[2] & 0x7f) | ((p[4] & 0xf0) << 3));
                f->pressure = (p[0] & 4) ? 0 : p[5] & 0x7f;
                alps_decode_buttons_v3(f, p);
        } else {
                f->fingers = ((p[0] & 0x6) >> 1 |
                     (p[0] & 0x10) >> 2);

                palm_data = (p[1] & 0x7f) |
                            ((p[2] & 0x7f) << 7) |
                            ((p[4] & 0x7f) << 14) |
                            ((p[5] & 0x7f) << 21) |
                            ((p[3] & 0x07) << 28) |
                            (((u64)p[3] & 0x70) << 27) |
                            (((u64)p[0] & 0x01) << 34);

                /* Y-profile is stored in P(0) to p(n-1), n = y_bits; */
                f->y_map = palm_data & (BIT(priv->y_bits) - 1);

                /* X-profile is stored in p(n) to p(n+m-1), m = x_bits; */
                f->x_map = (palm_data >> priv->y_bits) &
                           (BIT(priv->x_bits) - 1);
        }

        return 0;
}

static void alps_process_touchpad_packet_v3_v5(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        unsigned char *packet = psmouse->packet;
        struct input_dev *dev2 = priv->dev2;
        struct alps_fields *f = &priv->f;
        int fingers = 0;

        memset(f, 0, sizeof(*f));

        priv->decode_fields(f, packet, psmouse);

        /*
         * There's no single feature of touchpad position and bitmap packets
         * that can be used to distinguish between them. We rely on the fact
         * that a bitmap packet should always follow a position packet with
         * bit 6 of packet[4] set.
         */
        if (priv->multi_packet) {
                /*
                 * Sometimes a position packet will indicate a multi-packet
                 * sequence, but then what follows is another position
                 * packet. Check for this, and when it happens process the
                 * position packet as usual.
                 */
                if (f->is_mp) {
                        fingers = f->fingers;
                        /*
                         * Bitmap processing uses position packet's coordinate
                         * data, so we need to do decode it first.
                         */
                        priv->decode_fields(f, priv->multi_data, psmouse);
                        if (alps_process_bitmap(priv, f) == 0)
                                fingers = 0; /* Use st data */
                } else {
                        priv->multi_packet = 0;
                }
        }

        /*
         * Bit 6 of byte 0 is not usually set in position packets. The only
         * times it seems to be set is in situations where the data is
         * suspect anyway, e.g. a palm resting flat on the touchpad. Given
         * this combined with the fact that this bit is useful for filtering
         * out misidentified bitmap packets, we reject anything with this
         * bit set.
         */
        if (f->is_mp)
                return;

        if (!priv->multi_packet && f->first_mp) {
                priv->multi_packet = 1;
                memcpy(priv->multi_data, packet, sizeof(priv->multi_data));
                return;
        }

        priv->multi_packet = 0;

        /*
         * Sometimes the hardware sends a single packet with z = 0
         * in the middle of a stream. Real releases generate packets
         * with x, y, and z all zero, so these seem to be flukes.
         * Ignore them.
         */
        if (f->st.x && f->st.y && !f->pressure)
                return;

        alps_report_semi_mt_data(psmouse, fingers);

        if ((priv->flags & ALPS_DUALPOINT) &&
            !(priv->quirks & ALPS_QUIRK_TRACKSTICK_BUTTONS)) {
                input_report_key(dev2, BTN_LEFT, f->ts_left);
                input_report_key(dev2, BTN_RIGHT, f->ts_right);
                input_report_key(dev2, BTN_MIDDLE, f->ts_middle);
                input_sync(dev2);
        }
}

static void alps_process_packet_v3(struct psmouse *psmouse)
{
        unsigned char *packet = psmouse->packet;

        /*
         * v3 protocol packets come in three types, two representing
         * touchpad data and one representing trackstick data.
         * Trackstick packets seem to be distinguished by always
         * having 0x3f in the last byte. This value has never been
         * observed in the last byte of either of the other types
         * of packets.
         */
        if (packet[5] == 0x3f) {
                alps_process_trackstick_packet_v3(psmouse);
                return;
        }

        alps_process_touchpad_packet_v3_v5(psmouse);
}

static void alps_process_packet_v6(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        unsigned char *packet = psmouse->packet;
        struct input_dev *dev = psmouse->dev;
        struct input_dev *dev2 = priv->dev2;
        int x, y, z;

        /*
         * We can use Byte5 to distinguish if the packet is from Touchpad
         * or Trackpoint.
         * Touchpad:    0 - 0x7E
         * Trackpoint:  0x7F
         */
        if (packet[5] == 0x7F) {
                /* It should be a DualPoint when received Trackpoint packet */
                if (!(priv->flags & ALPS_DUALPOINT)) {
                        psmouse_warn(psmouse,
                                     "Rejected trackstick packet from non DualPoint device");
                        return;
                }

                /* Trackpoint packet */
                x = packet[1] | ((packet[3] & 0x20) << 2);
                y = packet[2] | ((packet[3] & 0x40) << 1);
                z = packet[4];

                /* To prevent the cursor jump when finger lifted */
                if (x == 0x7F && y == 0x7F && z == 0x7F)
                        x = y = z = 0;

                /* Divide 4 since trackpoint's speed is too fast */
                input_report_rel(dev2, REL_X, (s8)x / 4);
                input_report_rel(dev2, REL_Y, -((s8)y / 4));

                psmouse_report_standard_buttons(dev2, packet[3]);

                input_sync(dev2);
                return;
        }

        /* Touchpad packet */
        x = packet[1] | ((packet[3] & 0x78) << 4);
        y = packet[2] | ((packet[4] & 0x78) << 4);
        z = packet[5];

        if (z > 30)
                input_report_key(dev, BTN_TOUCH, 1);
        if (z < 25)
                input_report_key(dev, BTN_TOUCH, 0);

        if (z > 0) {
                input_report_abs(dev, ABS_X, x);
                input_report_abs(dev, ABS_Y, y);
        }

        input_report_abs(dev, ABS_PRESSURE, z);
        input_report_key(dev, BTN_TOOL_FINGER, z > 0);

        /* v6 touchpad does not have middle button */
        packet[3] &= ~BIT(2);
        psmouse_report_standard_buttons(dev2, packet[3]);

        input_sync(dev);
}

static void alps_process_packet_v4(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        unsigned char *packet = psmouse->packet;
        struct alps_fields *f = &priv->f;
        int offset;

        /*
         * v4 has a 6-byte encoding for bitmap data, but this data is
         * broken up between 3 normal packets. Use priv->multi_packet to
         * track our position in the bitmap packet.
         */
        if (packet[6] & 0x40) {
                /* sync, reset position */
                priv->multi_packet = 0;
        }

        if (WARN_ON_ONCE(priv->multi_packet > 2))
                return;

        offset = 2 * priv->multi_packet;
        priv->multi_data[offset] = packet[6];
        priv->multi_data[offset + 1] = packet[7];

        f->left = !!(packet[4] & 0x01);
        f->right = !!(packet[4] & 0x02);

        f->st.x = ((packet[1] & 0x7f) << 4) | ((packet[3] & 0x30) >> 2) |
                  ((packet[0] & 0x30) >> 4);
        f->st.y = ((packet[2] & 0x7f) << 4) | (packet[3] & 0x0f);
        f->pressure = packet[5] & 0x7f;

        if (++priv->multi_packet > 2) {
                priv->multi_packet = 0;

                f->x_map = ((priv->multi_data[2] & 0x1f) << 10) |
                           ((priv->multi_data[3] & 0x60) << 3) |
                           ((priv->multi_data[0] & 0x3f) << 2) |
                           ((priv->multi_data[1] & 0x60) >> 5);
                f->y_map = ((priv->multi_data[5] & 0x01) << 10) |
                           ((priv->multi_data[3] & 0x1f) << 5) |
                            (priv->multi_data[1] & 0x1f);

                f->fingers = alps_process_bitmap(priv, f);
        }

        alps_report_semi_mt_data(psmouse, f->fingers);
}

static bool alps_is_valid_package_v7(struct psmouse *psmouse)
{
        switch (psmouse->pktcnt) {
        case 3:
                return (psmouse->packet[2] & 0x40) == 0x40;
        case 4:
                return (psmouse->packet[3] & 0x48) == 0x48;
        case 6:
                return (psmouse->packet[5] & 0x40) == 0x00;
        }
        return true;
}

static unsigned char alps_get_packet_id_v7(char *byte)
{
        unsigned char packet_id;

        if (byte[4] & 0x40)
                packet_id = V7_PACKET_ID_TWO;
        else if (byte[4] & 0x01)
                packet_id = V7_PACKET_ID_MULTI;
        else if ((byte[0] & 0x10) && !(byte[4] & 0x43))
                packet_id = V7_PACKET_ID_NEW;
        else if (byte[1] == 0x00 && byte[4] == 0x00)
                packet_id = V7_PACKET_ID_IDLE;
        else
                packet_id = V7_PACKET_ID_UNKNOWN;

        return packet_id;
}

static void alps_get_finger_coordinate_v7(struct input_mt_pos *mt,
                                          unsigned char *pkt,
                                          unsigned char pkt_id)
{
        mt[0].x = ((pkt[2] & 0x80) << 4);
        mt[0].x |= ((pkt[2] & 0x3F) << 5);
        mt[0].x |= ((pkt[3] & 0x30) >> 1);
        mt[0].x |= (pkt[3] & 0x07);
        mt[0].y = (pkt[1] << 3) | (pkt[0] & 0x07);

        mt[1].x = ((pkt[3] & 0x80) << 4);
        mt[1].x |= ((pkt[4] & 0x80) << 3);
        mt[1].x |= ((pkt[4] & 0x3F) << 4);
        mt[1].y = ((pkt[5] & 0x80) << 3);
        mt[1].y |= ((pkt[5] & 0x3F) << 4);

        switch (pkt_id) {
        case V7_PACKET_ID_TWO:
                mt[1].x &= ~0x000F;
                mt[1].y |= 0x000F;
                /* Detect false-positive touches where x & y report max value */
                if (mt[1].y == 0x7ff && mt[1].x == 0xff0) {
                        mt[1].x = 0;
                        /* y gets set to 0 at the end of this function */
                }
                break;

        case V7_PACKET_ID_MULTI:
                mt[1].x &= ~0x003F;
                mt[1].y &= ~0x0020;
                mt[1].y |= ((pkt[4] & 0x02) << 4);
                mt[1].y |= 0x001F;
                break;

        case V7_PACKET_ID_NEW:
                mt[1].x &= ~0x003F;
                mt[1].x |= (pkt[0] & 0x20);
                mt[1].y |= 0x000F;
                break;
        }

        mt[0].y = 0x7FF - mt[0].y;
        mt[1].y = 0x7FF - mt[1].y;
}

static int alps_get_mt_count(struct input_mt_pos *mt)
{
        int i, fingers = 0;

        for (i = 0; i < MAX_TOUCHES; i++) {
                if (mt[i].x != 0 || mt[i].y != 0)
                        fingers++;
        }

        return fingers;
}

static int alps_decode_packet_v7(struct alps_fields *f,
                                  unsigned char *p,
                                  struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        unsigned char pkt_id;

        pkt_id = alps_get_packet_id_v7(p);
        if (pkt_id == V7_PACKET_ID_IDLE)
                return 0;
        if (pkt_id == V7_PACKET_ID_UNKNOWN)
                return -1;
        /*
         * NEW packets are send to indicate a discontinuity in the finger
         * coordinate reporting. Specifically a finger may have moved from
         * slot 0 to 1 or vice versa. INPUT_MT_TRACK takes care of this for
         * us.
         *
         * NEW packets have 3 problems:
         * 1) They do not contain middle / right button info (on non clickpads)
         *    this can be worked around by preserving the old button state
         * 2) They do not contain an accurate fingercount, and they are
         *    typically send when the number of fingers changes. We cannot use
         *    the old finger count as that may mismatch with the amount of
         *    touch coordinates we've available in the NEW packet
         * 3) Their x data for the second touch is inaccurate leading to
         *    a possible jump of the x coordinate by 16 units when the first
         *    non NEW packet comes in
         * Since problems 2 & 3 cannot be worked around, just ignore them.
         */
        if (pkt_id == V7_PACKET_ID_NEW)
                return 1;

        alps_get_finger_coordinate_v7(f->mt, p, pkt_id);

        if (pkt_id == V7_PACKET_ID_TWO)
                f->fingers = alps_get_mt_count(f->mt);
        else /* pkt_id == V7_PACKET_ID_MULTI */
                f->fingers = 3 + (p[5] & 0x03);

        f->left = (p[0] & 0x80) >> 7;
        if (priv->flags & ALPS_BUTTONPAD) {
                if (p[0] & 0x20)
                        f->fingers++;
                if (p[0] & 0x10)
                        f->fingers++;
        } else {
                f->right = (p[0] & 0x20) >> 5;
                f->middle = (p[0] & 0x10) >> 4;
        }

        /* Sometimes a single touch is reported in mt[1] rather then mt[0] */
        if (f->fingers == 1 && f->mt[0].x == 0 && f->mt[0].y == 0) {
                f->mt[0].x = f->mt[1].x;
                f->mt[0].y = f->mt[1].y;
                f->mt[1].x = 0;
                f->mt[1].y = 0;
        }

        return 0;
}

static void alps_process_trackstick_packet_v7(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        unsigned char *packet = psmouse->packet;
        struct input_dev *dev2 = priv->dev2;
        int x, y, z;

        /* It should be a DualPoint when received trackstick packet */
        if (!(priv->flags & ALPS_DUALPOINT)) {
                psmouse_warn(psmouse,
                             "Rejected trackstick packet from non DualPoint device");
                return;
        }

        x = ((packet[2] & 0xbf)) | ((packet[3] & 0x10) << 2);
        y = (packet[3] & 0x07) | (packet[4] & 0xb8) |
            ((packet[3] & 0x20) << 1);
        z = (packet[5] & 0x3f) | ((packet[3] & 0x80) >> 1);

        input_report_rel(dev2, REL_X, (s8)x);
        input_report_rel(dev2, REL_Y, -((s8)y));
        input_report_abs(dev2, ABS_PRESSURE, z);

        psmouse_report_standard_buttons(dev2, packet[1]);

        input_sync(dev2);
}

static void alps_process_touchpad_packet_v7(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        struct input_dev *dev = psmouse->dev;
        struct alps_fields *f = &priv->f;

        memset(f, 0, sizeof(*f));

        if (priv->decode_fields(f, psmouse->packet, psmouse))
                return;

        alps_report_mt_data(psmouse, alps_get_mt_count(f->mt));

        input_mt_report_finger_count(dev, f->fingers);

        input_report_key(dev, BTN_LEFT, f->left);
        input_report_key(dev, BTN_RIGHT, f->right);
        input_report_key(dev, BTN_MIDDLE, f->middle);

        input_sync(dev);
}

static void alps_process_packet_v7(struct psmouse *psmouse)
{
        unsigned char *packet = psmouse->packet;

        if (packet[0] == 0x48 && (packet[4] & 0x47) == 0x06)
                alps_process_trackstick_packet_v7(psmouse);
        else
                alps_process_touchpad_packet_v7(psmouse);
}

static enum SS4_PACKET_ID alps_get_pkt_id_ss4_v2(unsigned char *byte)
{
        enum SS4_PACKET_ID pkt_id = SS4_PACKET_ID_IDLE;

        switch (byte[3] & 0x30) {
        case 0x00:
                if (SS4_IS_IDLE_V2(byte)) {
                        pkt_id = SS4_PACKET_ID_IDLE;
                } else {
                        pkt_id = SS4_PACKET_ID_ONE;
                }
                break;
        case 0x10:
                /* two-finger finger positions */
                pkt_id = SS4_PACKET_ID_TWO;
                break;
        case 0x20:
                /* stick pointer */
                pkt_id = SS4_PACKET_ID_STICK;
                break;
        case 0x30:
                /* third and fourth finger positions */
                pkt_id = SS4_PACKET_ID_MULTI;
                break;
        }

        return pkt_id;
}

static int alps_decode_ss4_v2(struct alps_fields *f,
                              unsigned char *p, struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        enum SS4_PACKET_ID pkt_id;
        unsigned int no_data_x, no_data_y;

        pkt_id = alps_get_pkt_id_ss4_v2(p);

        /* Current packet is 1Finger coordinate packet */
        switch (pkt_id) {
        case SS4_PACKET_ID_ONE:
                f->mt[0].x = SS4_1F_X_V2(p);
                f->mt[0].y = SS4_1F_Y_V2(p);
                f->pressure = ((SS4_1F_Z_V2(p)) * 2) & 0x7f;
                /*
                 * When a button is held the device will give us events
                 * with x, y, and pressure of 0. This causes annoying jumps
                 * if a touch is released while the button is held.
                 * Handle this by claiming zero contacts.
                 */
                f->fingers = f->pressure > 0 ? 1 : 0;
                f->first_mp = 0;
                f->is_mp = 0;
                break;

        case SS4_PACKET_ID_TWO:
                if (priv->flags & ALPS_BUTTONPAD) {
                        if (IS_SS4PLUS_DEV(priv->dev_id)) {
                                f->mt[0].x = SS4_PLUS_BTL_MF_X_V2(p, 0);
                                f->mt[1].x = SS4_PLUS_BTL_MF_X_V2(p, 1);
                        } else {
                                f->mt[0].x = SS4_BTL_MF_X_V2(p, 0);
                                f->mt[1].x = SS4_BTL_MF_X_V2(p, 1);
                        }
                        f->mt[0].y = SS4_BTL_MF_Y_V2(p, 0);
                        f->mt[1].y = SS4_BTL_MF_Y_V2(p, 1);
                } else {
                        if (IS_SS4PLUS_DEV(priv->dev_id)) {
                                f->mt[0].x = SS4_PLUS_STD_MF_X_V2(p, 0);
                                f->mt[1].x = SS4_PLUS_STD_MF_X_V2(p, 1);
                        } else {
                                f->mt[0].x = SS4_STD_MF_X_V2(p, 0);
                                f->mt[1].x = SS4_STD_MF_X_V2(p, 1);
                        }
                        f->mt[0].y = SS4_STD_MF_Y_V2(p, 0);
                        f->mt[1].y = SS4_STD_MF_Y_V2(p, 1);
                }
                f->pressure = SS4_MF_Z_V2(p, 0) ? 0x30 : 0;

                if (SS4_IS_MF_CONTINUE(p)) {
                        f->first_mp = 1;
                } else {
                        f->fingers = 2;
                        f->first_mp = 0;
                }
                f->is_mp = 0;

                break;

        case SS4_PACKET_ID_MULTI:
                if (priv->flags & ALPS_BUTTONPAD) {
                        if (IS_SS4PLUS_DEV(priv->dev_id)) {
                                f->mt[2].x = SS4_PLUS_BTL_MF_X_V2(p, 0);
                                f->mt[3].x = SS4_PLUS_BTL_MF_X_V2(p, 1);
                                no_data_x = SS4_PLUS_MFPACKET_NO_AX_BL;
                        } else {
                                f->mt[2].x = SS4_BTL_MF_X_V2(p, 0);
                                f->mt[3].x = SS4_BTL_MF_X_V2(p, 1);
                                no_data_x = SS4_MFPACKET_NO_AX_BL;
                        }
                        no_data_y = SS4_MFPACKET_NO_AY_BL;

                        f->mt[2].y = SS4_BTL_MF_Y_V2(p, 0);
                        f->mt[3].y = SS4_BTL_MF_Y_V2(p, 1);
                } else {
                        if (IS_SS4PLUS_DEV(priv->dev_id)) {
                                f->mt[2].x = SS4_PLUS_STD_MF_X_V2(p, 0);
                                f->mt[3].x = SS4_PLUS_STD_MF_X_V2(p, 1);
                                no_data_x = SS4_PLUS_MFPACKET_NO_AX;
                        } else {
                                f->mt[2].x = SS4_STD_MF_X_V2(p, 0);
                                f->mt[3].x = SS4_STD_MF_X_V2(p, 1);
                                no_data_x = SS4_MFPACKET_NO_AX;
                        }
                        no_data_y = SS4_MFPACKET_NO_AY;

                        f->mt[2].y = SS4_STD_MF_Y_V2(p, 0);
                        f->mt[3].y = SS4_STD_MF_Y_V2(p, 1);
                }

                f->first_mp = 0;
                f->is_mp = 1;

                if (SS4_IS_5F_DETECTED(p)) {
                        f->fingers = 5;
                } else if (f->mt[3].x == no_data_x &&
                             f->mt[3].y == no_data_y) {
                        f->mt[3].x = 0;
                        f->mt[3].y = 0;
                        f->fingers = 3;
                } else {
                        f->fingers = 4;
                }
                break;

        case SS4_PACKET_ID_STICK:
                /*
                 * x, y, and pressure are decoded in
                 * alps_process_packet_ss4_v2()
                 */
                f->first_mp = 0;
                f->is_mp = 0;
                break;

        case SS4_PACKET_ID_IDLE:
        default:
                memset(f, 0, sizeof(struct alps_fields));
                break;
        }

        /* handle buttons */
        if (pkt_id == SS4_PACKET_ID_STICK) {
                f->ts_left = !!(SS4_BTN_V2(p) & 0x01);
                f->ts_right = !!(SS4_BTN_V2(p) & 0x02);
                f->ts_middle = !!(SS4_BTN_V2(p) & 0x04);
        } else {
                f->left = !!(SS4_BTN_V2(p) & 0x01);
                if (!(priv->flags & ALPS_BUTTONPAD)) {
                        f->right = !!(SS4_BTN_V2(p) & 0x02);
                        f->middle = !!(SS4_BTN_V2(p) & 0x04);
                }
        }

        return 0;
}

static void alps_process_packet_ss4_v2(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        unsigned char *packet = psmouse->packet;
        struct input_dev *dev = psmouse->dev;
        struct input_dev *dev2 = priv->dev2;
        struct alps_fields *f = &priv->f;

        memset(f, 0, sizeof(struct alps_fields));
        priv->decode_fields(f, packet, psmouse);
        if (priv->multi_packet) {
                /*
                 * Sometimes the first packet will indicate a multi-packet
                 * sequence, but sometimes the next multi-packet would not
                 * come. Check for this, and when it happens process the
                 * position packet as usual.
                 */
                if (f->is_mp) {
                        /* Now process the 1st packet */
                        priv->decode_fields(f, priv->multi_data, psmouse);
                } else {
                        priv->multi_packet = 0;
                }
        }

        /*
         * "f.is_mp" would always be '0' after merging the 1st and 2nd packet.
         * When it is set, it means 2nd packet comes without 1st packet come.
         */
        if (f->is_mp)
                return;

        /* Save the first packet */
        if (!priv->multi_packet && f->first_mp) {
                priv->multi_packet = 1;
                memcpy(priv->multi_data, packet, sizeof(priv->multi_data));
                return;
        }

        priv->multi_packet = 0;

        /* Report trackstick */
        if (alps_get_pkt_id_ss4_v2(packet) == SS4_PACKET_ID_STICK) {
                if (!(priv->flags & ALPS_DUALPOINT)) {
                        psmouse_warn(psmouse,
                                     "Rejected trackstick packet from non DualPoint device");
                        return;
                }

                input_report_rel(dev2, REL_X, SS4_TS_X_V2(packet));
                input_report_rel(dev2, REL_Y, SS4_TS_Y_V2(packet));
                input_report_abs(dev2, ABS_PRESSURE, SS4_TS_Z_V2(packet));

                input_report_key(dev2, BTN_LEFT, f->ts_left);
                input_report_key(dev2, BTN_RIGHT, f->ts_right);
                input_report_key(dev2, BTN_MIDDLE, f->ts_middle);

                input_sync(dev2);
                return;
        }

        /* Report touchpad */
        alps_report_mt_data(psmouse, (f->fingers <= 4) ? f->fingers : 4);

        input_mt_report_finger_count(dev, f->fingers);

        input_report_key(dev, BTN_LEFT, f->left);
        input_report_key(dev, BTN_RIGHT, f->right);
        input_report_key(dev, BTN_MIDDLE, f->middle);

        input_report_abs(dev, ABS_PRESSURE, f->pressure);
        input_sync(dev);
}

static bool alps_is_valid_package_ss4_v2(struct psmouse *psmouse)
{
        if (psmouse->pktcnt == 4 && ((psmouse->packet[3] & 0x08) != 0x08))
                return false;
        if (psmouse->pktcnt == 6 && ((psmouse->packet[5] & 0x10) != 0x0))
                return false;
        return true;
}

static DEFINE_MUTEX(alps_mutex);

static int alps_do_register_bare_ps2_mouse(struct alps_data *priv)
{
        struct psmouse *psmouse = priv->psmouse;
        struct input_dev *dev3;
        int error;

        dev3 = input_allocate_device();
        if (!dev3) {
                psmouse_err(psmouse, "failed to allocate secondary device\n");
                return -ENOMEM;
        }

        scnprintf(priv->phys3, sizeof(priv->phys3), "%s/%s",
                  psmouse->ps2dev.serio->phys,
                  (priv->dev2 ? "input2" : "input1"));
        dev3->phys = priv->phys3;

        /*
         * format of input device name is: "protocol vendor name"
         * see function psmouse_switch_protocol() in psmouse-base.c
         */
        dev3->name = "PS/2 ALPS Mouse";

        dev3->id.bustype = BUS_I8042;
        dev3->id.vendor  = 0x0002;
        dev3->id.product = PSMOUSE_PS2;
        dev3->id.version = 0x0000;
        dev3->dev.parent = &psmouse->ps2dev.serio->dev;

        input_set_capability(dev3, EV_REL, REL_X);
        input_set_capability(dev3, EV_REL, REL_Y);
        input_set_capability(dev3, EV_KEY, BTN_LEFT);
        input_set_capability(dev3, EV_KEY, BTN_RIGHT);
        input_set_capability(dev3, EV_KEY, BTN_MIDDLE);

        __set_bit(INPUT_PROP_POINTER, dev3->propbit);

        error = input_register_device(dev3);
        if (error) {
                psmouse_err(psmouse,
                            "failed to register secondary device: %d\n",
                            error);
                goto err_free_input;
        }

        priv->dev3 = dev3;
        return 0;

err_free_input:
        input_free_device(dev3);
        return error;
}

static void alps_register_bare_ps2_mouse(struct work_struct *work)
{
        struct alps_data *priv = container_of(work, struct alps_data,
                                              dev3_register_work.work);
        int error;

        guard(mutex)(&alps_mutex);

        if (!priv->dev3) {
                error = alps_do_register_bare_ps2_mouse(priv);
                if (error) {
                        /*
                         * Save the error code so that we can detect that we
                         * already tried to create the device.
                         */
                        priv->dev3 = ERR_PTR(error);
                }
        }
}

static void alps_report_bare_ps2_packet(struct psmouse *psmouse,
                                        unsigned char packet[],
                                        bool report_buttons)
{
        struct alps_data *priv = psmouse->private;
        struct input_dev *dev, *dev2 = NULL;

        /* Figure out which device to use to report the bare packet */
        if (priv->proto_version == ALPS_PROTO_V2 &&
            (priv->flags & ALPS_DUALPOINT)) {
                /* On V2 devices the DualPoint Stick reports bare packets */
                dev = priv->dev2;
                dev2 = psmouse->dev;
        } else if (unlikely(IS_ERR_OR_NULL(priv->dev3))) {
                /* Register dev3 mouse if we received PS/2 packet first time */
                if (!IS_ERR(priv->dev3))
                        psmouse_queue_work(psmouse, &priv->dev3_register_work,
                                           0);
                return;
        } else {
                dev = priv->dev3;
        }

        if (report_buttons)
                alps_report_buttons(dev, dev2,
                                packet[0] & 1, packet[0] & 2, packet[0] & 4);

        psmouse_report_standard_motion(dev, packet);

        input_sync(dev);
}

static psmouse_ret_t alps_handle_interleaved_ps2(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;

        if (psmouse->pktcnt < 6)
                return PSMOUSE_GOOD_DATA;

        if (psmouse->pktcnt == 6) {
                /*
                 * Start a timer to flush the packet if it ends up last
                 * 6-byte packet in the stream. Timer needs to fire
                 * psmouse core times out itself. 20 ms should be enough
                 * to decide if we are getting more data or not.
                 */
                mod_timer(&priv->timer, jiffies + msecs_to_jiffies(20));
                return PSMOUSE_GOOD_DATA;
        }

        timer_delete(&priv->timer);

        if (psmouse->packet[6] & 0x80) {

                /*
                 * Highest bit is set - that means we either had
                 * complete ALPS packet and this is start of the
                 * next packet or we got garbage.
                 */

                if (((psmouse->packet[3] |
                      psmouse->packet[4] |
                      psmouse->packet[5]) & 0x80) ||
                    (!alps_is_valid_first_byte(priv, psmouse->packet[6]))) {
                        psmouse_dbg(psmouse,
                                    "refusing packet %4ph (suspected interleaved ps/2)\n",
                                    psmouse->packet + 3);
                        return PSMOUSE_BAD_DATA;
                }

                priv->process_packet(psmouse);

                /* Continue with the next packet */
                psmouse->packet[0] = psmouse->packet[6];
                psmouse->pktcnt = 1;

        } else {

                /*
                 * High bit is 0 - that means that we indeed got a PS/2
                 * packet in the middle of ALPS packet.
                 *
                 * There is also possibility that we got 6-byte ALPS
                 * packet followed  by 3-byte packet from trackpoint. We
                 * can not distinguish between these 2 scenarios but
                 * because the latter is unlikely to happen in course of
                 * normal operation (user would need to press all
                 * buttons on the pad and start moving trackpoint
                 * without touching the pad surface) we assume former.
                 * Even if we are wrong the wost thing that would happen
                 * the cursor would jump but we should not get protocol
                 * de-synchronization.
                 */

                alps_report_bare_ps2_packet(psmouse, &psmouse->packet[3],
                                            false);

                /*
                 * Continue with the standard ALPS protocol handling,
                 * but make sure we won't process it as an interleaved
                 * packet again, which may happen if all buttons are
                 * pressed. To avoid this let's reset the 4th bit which
                 * is normally 1.
                 */
                psmouse->packet[3] = psmouse->packet[6] & 0xf7;
                psmouse->pktcnt = 4;
        }

        return PSMOUSE_GOOD_DATA;
}

static void alps_flush_packet(struct timer_list *t)
{
        struct alps_data *priv = timer_container_of(priv, t, timer);
        struct psmouse *psmouse = priv->psmouse;

        guard(serio_pause_rx)(psmouse->ps2dev.serio);

        if (psmouse->pktcnt == psmouse->pktsize) {

                /*
                 * We did not any more data in reasonable amount of time.
                 * Validate the last 3 bytes and process as a standard
                 * ALPS packet.
                 */
                if ((psmouse->packet[3] |
                     psmouse->packet[4] |
                     psmouse->packet[5]) & 0x80) {
                        psmouse_dbg(psmouse,
                                    "refusing packet %3ph (suspected interleaved ps/2)\n",
                                    psmouse->packet + 3);
                } else {
                        priv->process_packet(psmouse);
                }
                psmouse->pktcnt = 0;
        }
}

static psmouse_ret_t alps_process_byte(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;

        /*
         * Check if we are dealing with a bare PS/2 packet, presumably from
         * a device connected to the external PS/2 port. Because bare PS/2
         * protocol does not have enough constant bits to self-synchronize
         * properly we only do this if the device is fully synchronized.
         * Can not distinguish V8's first byte from PS/2 packet's
         */
        if (priv->proto_version != ALPS_PROTO_V8 &&
            !psmouse->out_of_sync_cnt &&
            (psmouse->packet[0] & 0xc8) == 0x08) {

                if (psmouse->pktcnt == 3) {
                        alps_report_bare_ps2_packet(psmouse, psmouse->packet,
                                                    true);
                        return PSMOUSE_FULL_PACKET;
                }
                return PSMOUSE_GOOD_DATA;
        }

        /* Check for PS/2 packet stuffed in the middle of ALPS packet. */

        if ((priv->flags & ALPS_PS2_INTERLEAVED) &&
            psmouse->pktcnt >= 4 && (psmouse->packet[3] & 0x0f) == 0x0f) {
                return alps_handle_interleaved_ps2(psmouse);
        }

        if (!alps_is_valid_first_byte(priv, psmouse->packet[0])) {
                psmouse_dbg(psmouse,
                            "refusing packet[0] = %x (mask0 = %x, byte0 = %x)\n",
                            psmouse->packet[0], priv->mask0, priv->byte0);
                return PSMOUSE_BAD_DATA;
        }

        /* Bytes 2 - pktsize should have 0 in the highest bit */
        if (priv->proto_version < ALPS_PROTO_V5 &&
            psmouse->pktcnt >= 2 && psmouse->pktcnt <= psmouse->pktsize &&
            (psmouse->packet[psmouse->pktcnt - 1] & 0x80)) {
                psmouse_dbg(psmouse, "refusing packet[%i] = %x\n",
                            psmouse->pktcnt - 1,
                            psmouse->packet[psmouse->pktcnt - 1]);

                if (priv->proto_version == ALPS_PROTO_V3_RUSHMORE &&
                    psmouse->pktcnt == psmouse->pktsize) {
                        /*
                         * Some Dell boxes, such as Latitude E6440 or E7440
                         * with closed lid, quite often smash last byte of
                         * otherwise valid packet with 0xff. Given that the
                         * next packet is very likely to be valid let's
                         * report PSMOUSE_FULL_PACKET but not process data,
                         * rather than reporting PSMOUSE_BAD_DATA and
                         * filling the logs.
                         */
                        return PSMOUSE_FULL_PACKET;
                }

                return PSMOUSE_BAD_DATA;
        }

        if ((priv->proto_version == ALPS_PROTO_V7 &&
                        !alps_is_valid_package_v7(psmouse)) ||
            (priv->proto_version == ALPS_PROTO_V8 &&
                        !alps_is_valid_package_ss4_v2(psmouse))) {
                psmouse_dbg(psmouse, "refusing packet[%i] = %x\n",
                            psmouse->pktcnt - 1,
                            psmouse->packet[psmouse->pktcnt - 1]);
                return PSMOUSE_BAD_DATA;
        }

        if (psmouse->pktcnt == psmouse->pktsize) {
                priv->process_packet(psmouse);
                return PSMOUSE_FULL_PACKET;
        }

        return PSMOUSE_GOOD_DATA;
}

static int alps_command_mode_send_nibble(struct psmouse *psmouse, int nibble)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        struct alps_data *priv = psmouse->private;
        int command;
        unsigned char *param;
        unsigned char dummy[4];

        BUG_ON(nibble > 0xf);

        command = priv->nibble_commands[nibble].command;
        param = (command & 0x0f00) ?
                dummy : (unsigned char *)&priv->nibble_commands[nibble].data;

        if (ps2_command(ps2dev, param, command))
                return -1;

        return 0;
}

static int alps_command_mode_set_addr(struct psmouse *psmouse, int addr)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        struct alps_data *priv = psmouse->private;
        int i, nibble;

        if (ps2_command(ps2dev, NULL, priv->addr_command))
                return -1;

        for (i = 12; i >= 0; i -= 4) {
                nibble = (addr >> i) & 0xf;
                if (alps_command_mode_send_nibble(psmouse, nibble))
                        return -1;
        }

        return 0;
}

static int __alps_command_mode_read_reg(struct psmouse *psmouse, int addr)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        unsigned char param[4];

        if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
                return -1;

        /*
         * The address being read is returned in the first two bytes
         * of the result. Check that this address matches the expected
         * address.
         */
        if (addr != ((param[0] << 8) | param[1]))
                return -1;

        return param[2];
}

static int alps_command_mode_read_reg(struct psmouse *psmouse, int addr)
{
        if (alps_command_mode_set_addr(psmouse, addr))
                return -1;
        return __alps_command_mode_read_reg(psmouse, addr);
}

static int __alps_command_mode_write_reg(struct psmouse *psmouse, u8 value)
{
        if (alps_command_mode_send_nibble(psmouse, (value >> 4) & 0xf))
                return -1;
        if (alps_command_mode_send_nibble(psmouse, value & 0xf))
                return -1;
        return 0;
}

static int alps_command_mode_write_reg(struct psmouse *psmouse, int addr,
                                       u8 value)
{
        if (alps_command_mode_set_addr(psmouse, addr))
                return -1;
        return __alps_command_mode_write_reg(psmouse, value);
}

static int alps_rpt_cmd(struct psmouse *psmouse, int init_command,
                        int repeated_command, unsigned char *param)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;

        param[0] = 0;
        if (init_command && ps2_command(ps2dev, param, init_command))
                return -EIO;

        if (ps2_command(ps2dev,  NULL, repeated_command) ||
            ps2_command(ps2dev,  NULL, repeated_command) ||
            ps2_command(ps2dev,  NULL, repeated_command))
                return -EIO;

        param[0] = param[1] = param[2] = 0xff;
        if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
                return -EIO;

        psmouse_dbg(psmouse, "%2.2X report: %3ph\n",
                    repeated_command, param);
        return 0;
}

static bool alps_check_valid_firmware_id(unsigned char id[])
{
        if (id[0] == 0x73)
                return true;

        if (id[0] == 0x88 &&
            (id[1] == 0x07 ||
             id[1] == 0x08 ||
             (id[1] & 0xf0) == 0xb0 ||
             (id[1] & 0xf0) == 0xc0)) {
                return true;
        }

        return false;
}

static int alps_enter_command_mode(struct psmouse *psmouse)
{
        unsigned char param[4];

        if (alps_rpt_cmd(psmouse, 0, PSMOUSE_CMD_RESET_WRAP, param)) {
                psmouse_err(psmouse, "failed to enter command mode\n");
                return -1;
        }

        if (!alps_check_valid_firmware_id(param)) {
                psmouse_dbg(psmouse,
                            "unknown response while entering command mode\n");
                return -1;
        }
        return 0;
}

static inline int alps_exit_command_mode(struct psmouse *psmouse)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSTREAM))
                return -1;
        return 0;
}

/*
 * For DualPoint devices select the device that should respond to
 * subsequent commands. It looks like glidepad is behind stickpointer,
 * I'd thought it would be other way around...
 */
static int alps_passthrough_mode_v2(struct psmouse *psmouse, bool enable)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        int cmd = enable ? PSMOUSE_CMD_SETSCALE21 : PSMOUSE_CMD_SETSCALE11;

        if (ps2_command(ps2dev, NULL, cmd) ||
            ps2_command(ps2dev, NULL, cmd) ||
            ps2_command(ps2dev, NULL, cmd) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE))
                return -1;

        /* we may get 3 more bytes, just ignore them */
        ps2_drain(ps2dev, 3, 100);

        return 0;
}

static int alps_absolute_mode_v1_v2(struct psmouse *psmouse)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;

        /* Try ALPS magic knock - 4 disable before enable */
        if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE))
                return -1;

        /*
         * Switch mouse to poll (remote) mode so motion data will not
         * get in our way
         */
        return ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETPOLL);
}

static int alps_monitor_mode_send_word(struct psmouse *psmouse, u16 word)
{
        int i, nibble;

        /*
         * b0-b11 are valid bits, send sequence is inverse.
         * e.g. when word = 0x0123, nibble send sequence is 3, 2, 1
         */
        for (i = 0; i <= 8; i += 4) {
                nibble = (word >> i) & 0xf;
                if (alps_command_mode_send_nibble(psmouse, nibble))
                        return -1;
        }

        return 0;
}

static int alps_monitor_mode_write_reg(struct psmouse *psmouse,
                                       u16 addr, u16 value)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;

        /* 0x0A0 is the command to write the word */
        if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE) ||
            alps_monitor_mode_send_word(psmouse, 0x0A0) ||
            alps_monitor_mode_send_word(psmouse, addr) ||
            alps_monitor_mode_send_word(psmouse, value) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE))
                return -1;

        return 0;
}

static int alps_monitor_mode(struct psmouse *psmouse, bool enable)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;

        if (enable) {
                /* EC E9 F5 F5 E7 E6 E7 E9 to enter monitor mode */
                if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_WRAP) ||
                    ps2_command(ps2dev, NULL, PSMOUSE_CMD_GETINFO) ||
                    ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) ||
                    ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) ||
                    ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) ||
                    ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) ||
                    ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) ||
                    ps2_command(ps2dev, NULL, PSMOUSE_CMD_GETINFO))
                        return -1;
        } else {
                /* EC to exit monitor mode */
                if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_WRAP))
                        return -1;
        }

        return 0;
}

static int alps_absolute_mode_v6(struct psmouse *psmouse)
{
        u16 reg_val = 0x181;
        int ret;

        /* enter monitor mode, to write the register */
        if (alps_monitor_mode(psmouse, true))
                return -1;

        ret = alps_monitor_mode_write_reg(psmouse, 0x000, reg_val);

        if (alps_monitor_mode(psmouse, false))
                ret = -1;

        return ret;
}

static int alps_get_status(struct psmouse *psmouse, char *param)
{
        /* Get status: 0xF5 0xF5 0xF5 0xE9 */
        if (alps_rpt_cmd(psmouse, 0, PSMOUSE_CMD_DISABLE, param))
                return -1;

        return 0;
}

/*
 * Turn touchpad tapping on or off. The sequences are:
 * 0xE9 0xF5 0xF5 0xF3 0x0A to enable,
 * 0xE9 0xF5 0xF5 0xE8 0x00 to disable.
 * My guess that 0xE9 (GetInfo) is here as a sync point.
 * For models that also have stickpointer (DualPoints) its tapping
 * is controlled separately (0xE6 0xE6 0xE6 0xF3 0x14|0x0A) but
 * we don't fiddle with it.
 */
static int alps_tap_mode(struct psmouse *psmouse, int enable)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        int cmd = enable ? PSMOUSE_CMD_SETRATE : PSMOUSE_CMD_SETRES;
        unsigned char tap_arg = enable ? 0x0A : 0x00;
        unsigned char param[4];

        if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) ||
            ps2_command(ps2dev, &tap_arg, cmd))
                return -1;

        if (alps_get_status(psmouse, param))
                return -1;

        return 0;
}

/*
 * alps_poll() - poll the touchpad for current motion packet.
 * Used in resync.
 */
static int alps_poll(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        unsigned char buf[sizeof(psmouse->packet)];
        bool poll_failed;

        if (priv->flags & ALPS_PASS)
                alps_passthrough_mode_v2(psmouse, true);

        poll_failed = ps2_command(&psmouse->ps2dev, buf,
                                  PSMOUSE_CMD_POLL | (psmouse->pktsize << 8)) < 0;

        if (priv->flags & ALPS_PASS)
                alps_passthrough_mode_v2(psmouse, false);

        if (poll_failed || (buf[0] & priv->mask0) != priv->byte0)
                return -1;

        if ((psmouse->badbyte & 0xc8) == 0x08) {
/*
 * Poll the track stick ...
 */
                if (ps2_command(&psmouse->ps2dev, buf, PSMOUSE_CMD_POLL | (3 << 8)))
                        return -1;
        }

        memcpy(psmouse->packet, buf, sizeof(buf));
        return 0;
}

static int alps_hw_init_v1_v2(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;

        if ((priv->flags & ALPS_PASS) &&
            alps_passthrough_mode_v2(psmouse, true)) {
                return -1;
        }

        if (alps_tap_mode(psmouse, true)) {
                psmouse_warn(psmouse, "Failed to enable hardware tapping\n");
                return -1;
        }

        if (alps_absolute_mode_v1_v2(psmouse)) {
                psmouse_err(psmouse, "Failed to enable absolute mode\n");
                return -1;
        }

        if ((priv->flags & ALPS_PASS) &&
            alps_passthrough_mode_v2(psmouse, false)) {
                return -1;
        }

        /* ALPS needs stream mode, otherwise it won't report any data */
        if (ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSTREAM)) {
                psmouse_err(psmouse, "Failed to enable stream mode\n");
                return -1;
        }

        return 0;
}

/* Must be in passthrough mode when calling this function */
static int alps_trackstick_enter_extended_mode_v3_v6(struct psmouse *psmouse)
{
        unsigned char param[2] = {0xC8, 0x14};

        if (ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) ||
            ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) ||
            ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) ||
            ps2_command(&psmouse->ps2dev, &param[0], PSMOUSE_CMD_SETRATE) ||
            ps2_command(&psmouse->ps2dev, &param[1], PSMOUSE_CMD_SETRATE))
                return -1;

        return 0;
}

static int alps_hw_init_v6(struct psmouse *psmouse)
{
        int ret;

        /* Enter passthrough mode to let trackpoint enter 6byte raw mode */
        if (alps_passthrough_mode_v2(psmouse, true))
                return -1;

        ret = alps_trackstick_enter_extended_mode_v3_v6(psmouse);

        if (alps_passthrough_mode_v2(psmouse, false))
                return -1;

        if (ret)
                return ret;

        if (alps_absolute_mode_v6(psmouse)) {
                psmouse_err(psmouse, "Failed to enable absolute mode\n");
                return -1;
        }

        return 0;
}

/*
 * Enable or disable passthrough mode to the trackstick.
 */
static int alps_passthrough_mode_v3(struct psmouse *psmouse,
                                    int reg_base, bool enable)
{
        int reg_val, ret = -1;

        if (alps_enter_command_mode(psmouse))
                return -1;

        reg_val = alps_command_mode_read_reg(psmouse, reg_base + 0x0008);
        if (reg_val == -1)
                goto error;

        if (enable)
                reg_val |= 0x01;
        else
                reg_val &= ~0x01;

        ret = __alps_command_mode_write_reg(psmouse, reg_val);

error:
        if (alps_exit_command_mode(psmouse))
                ret = -1;
        return ret;
}

/* Must be in command mode when calling this function */
static int alps_absolute_mode_v3(struct psmouse *psmouse)
{
        int reg_val;

        reg_val = alps_command_mode_read_reg(psmouse, 0x0004);
        if (reg_val == -1)
                return -1;

        reg_val |= 0x06;
        if (__alps_command_mode_write_reg(psmouse, reg_val))
                return -1;

        return 0;
}

static int alps_probe_trackstick_v3_v7(struct psmouse *psmouse, int reg_base)
{
        int ret = -EIO, reg_val;

        if (alps_enter_command_mode(psmouse))
                goto error;

        reg_val = alps_command_mode_read_reg(psmouse, reg_base + 0x08);
        if (reg_val == -1)
                goto error;

        /* bit 7: trackstick is present */
        ret = reg_val & 0x80 ? 0 : -ENODEV;

error:
        alps_exit_command_mode(psmouse);
        return ret;
}

static int alps_setup_trackstick_v3(struct psmouse *psmouse, int reg_base)
{
        int ret = 0;
        int reg_val;
        unsigned char param[4];

        /*
         * We need to configure trackstick to report data for touchpad in
         * extended format. And also we need to tell touchpad to expect data
         * from trackstick in extended format. Without this configuration
         * trackstick packets sent from touchpad are in basic format which is
         * different from what we expect.
         */

        if (alps_passthrough_mode_v3(psmouse, reg_base, true))
                return -EIO;

        /*
         * E7 report for the trackstick
         *
         * There have been reports of failures to seem to trace back
         * to the above trackstick check failing. When these occur
         * this E7 report fails, so when that happens we continue
         * with the assumption that there isn't a trackstick after
         * all.
         */
        if (alps_rpt_cmd(psmouse, 0, PSMOUSE_CMD_SETSCALE21, param)) {
                psmouse_warn(psmouse, "Failed to initialize trackstick (E7 report failed)\n");
                ret = -ENODEV;
        } else {
                psmouse_dbg(psmouse, "trackstick E7 report: %3ph\n", param);
                if (alps_trackstick_enter_extended_mode_v3_v6(psmouse)) {
                        psmouse_err(psmouse, "Failed to enter into trackstick extended mode\n");
                        ret = -EIO;
                }
        }

        if (alps_passthrough_mode_v3(psmouse, reg_base, false))
                return -EIO;

        if (ret)
                return ret;

        if (alps_enter_command_mode(psmouse))
                return -EIO;

        reg_val = alps_command_mode_read_reg(psmouse, reg_base + 0x08);
        if (reg_val == -1) {
                ret = -EIO;
        } else {
                /*
                 * Tell touchpad that trackstick is now in extended mode.
                 * If bit 1 isn't set the packet format is different.
                 */
                reg_val |= BIT(1);
                if (__alps_command_mode_write_reg(psmouse, reg_val))
                        ret = -EIO;
        }

        if (alps_exit_command_mode(psmouse))
                return -EIO;

        return ret;
}

static int alps_hw_init_v3(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        int reg_val;
        unsigned char param[4];

        if ((priv->flags & ALPS_DUALPOINT) &&
            alps_setup_trackstick_v3(psmouse, ALPS_REG_BASE_PINNACLE) == -EIO)
                goto error;

        if (alps_enter_command_mode(psmouse) ||
            alps_absolute_mode_v3(psmouse)) {
                psmouse_err(psmouse, "Failed to enter absolute mode\n");
                goto error;
        }

        reg_val = alps_command_mode_read_reg(psmouse, 0x0006);
        if (reg_val == -1)
                goto error;
        if (__alps_command_mode_write_reg(psmouse, reg_val | 0x01))
                goto error;

        reg_val = alps_command_mode_read_reg(psmouse, 0x0007);
        if (reg_val == -1)
                goto error;
        if (__alps_command_mode_write_reg(psmouse, reg_val | 0x01))
                goto error;

        if (alps_command_mode_read_reg(psmouse, 0x0144) == -1)
                goto error;
        if (__alps_command_mode_write_reg(psmouse, 0x04))
                goto error;

        if (alps_command_mode_read_reg(psmouse, 0x0159) == -1)
                goto error;
        if (__alps_command_mode_write_reg(psmouse, 0x03))
                goto error;

        if (alps_command_mode_read_reg(psmouse, 0x0163) == -1)
                goto error;
        if (alps_command_mode_write_reg(psmouse, 0x0163, 0x03))
                goto error;

        if (alps_command_mode_read_reg(psmouse, 0x0162) == -1)
                goto error;
        if (alps_command_mode_write_reg(psmouse, 0x0162, 0x04))
                goto error;

        alps_exit_command_mode(psmouse);

        /* Set rate and enable data reporting */
        param[0] = 0x64;
        if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE)) {
                psmouse_err(psmouse, "Failed to enable data reporting\n");
                return -1;
        }

        return 0;

error:
        /*
         * Leaving the touchpad in command mode will essentially render
         * it unusable until the machine reboots, so exit it here just
         * to be safe
         */
        alps_exit_command_mode(psmouse);
        return -1;
}

static int alps_get_v3_v7_resolution(struct psmouse *psmouse, int reg_pitch)
{
        int reg, x_pitch, y_pitch, x_electrode, y_electrode, x_phys, y_phys;
        struct alps_data *priv = psmouse->private;

        reg = alps_command_mode_read_reg(psmouse, reg_pitch);
        if (reg < 0)
                return reg;

        x_pitch = (s8)(reg << 4) >> 4; /* sign extend lower 4 bits */
        x_pitch = 50 + 2 * x_pitch; /* In 0.1 mm units */

        y_pitch = (s8)reg >> 4; /* sign extend upper 4 bits */
        y_pitch = 36 + 2 * y_pitch; /* In 0.1 mm units */

        reg = alps_command_mode_read_reg(psmouse, reg_pitch + 1);
        if (reg < 0)
                return reg;

        x_electrode = (s8)(reg << 4) >> 4; /* sign extend lower 4 bits */
        x_electrode = 17 + x_electrode;

        y_electrode = (s8)reg >> 4; /* sign extend upper 4 bits */
        y_electrode = 13 + y_electrode;

        x_phys = x_pitch * (x_electrode - 1); /* In 0.1 mm units */
        y_phys = y_pitch * (y_electrode - 1); /* In 0.1 mm units */

        priv->x_res = priv->x_max * 10 / x_phys; /* units / mm */
        priv->y_res = priv->y_max * 10 / y_phys; /* units / mm */

        psmouse_dbg(psmouse,
                    "pitch %dx%d num-electrodes %dx%d physical size %dx%d mm res %dx%d\n",
                    x_pitch, y_pitch, x_electrode, y_electrode,
                    x_phys / 10, y_phys / 10, priv->x_res, priv->y_res);

        return 0;
}

static int alps_hw_init_rushmore_v3(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        int reg_val, ret = -1;

        if (priv->flags & ALPS_DUALPOINT) {
                reg_val = alps_setup_trackstick_v3(psmouse,
                                                   ALPS_REG_BASE_RUSHMORE);
                if (reg_val == -EIO)
                        goto error;
        }

        if (alps_enter_command_mode(psmouse) ||
            alps_command_mode_read_reg(psmouse, 0xc2d9) == -1 ||
            alps_command_mode_write_reg(psmouse, 0xc2cb, 0x00))
                goto error;

        if (alps_get_v3_v7_resolution(psmouse, 0xc2da))
                goto error;

        reg_val = alps_command_mode_read_reg(psmouse, 0xc2c6);
        if (reg_val == -1)
                goto error;
        if (__alps_command_mode_write_reg(psmouse, reg_val & 0xfd))
                goto error;

        if (alps_command_mode_write_reg(psmouse, 0xc2c9, 0x64))
                goto error;

        /* enter absolute mode */
        reg_val = alps_command_mode_read_reg(psmouse, 0xc2c4);
        if (reg_val == -1)
                goto error;
        if (__alps_command_mode_write_reg(psmouse, reg_val | 0x02))
                goto error;

        alps_exit_command_mode(psmouse);
        return ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE);

error:
        alps_exit_command_mode(psmouse);
        return ret;
}

/* Must be in command mode when calling this function */
static int alps_absolute_mode_v4(struct psmouse *psmouse)
{
        int reg_val;

        reg_val = alps_command_mode_read_reg(psmouse, 0x0004);
        if (reg_val == -1)
                return -1;

        reg_val |= 0x02;
        if (__alps_command_mode_write_reg(psmouse, reg_val))
                return -1;

        return 0;
}

static int alps_hw_init_v4(struct psmouse *psmouse)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        unsigned char param[4];

        if (alps_enter_command_mode(psmouse))
                goto error;

        if (alps_absolute_mode_v4(psmouse)) {
                psmouse_err(psmouse, "Failed to enter absolute mode\n");
                goto error;
        }

        if (alps_command_mode_write_reg(psmouse, 0x0007, 0x8c))
                goto error;

        if (alps_command_mode_write_reg(psmouse, 0x0149, 0x03))
                goto error;

        if (alps_command_mode_write_reg(psmouse, 0x0160, 0x03))
                goto error;

        if (alps_command_mode_write_reg(psmouse, 0x017f, 0x15))
                goto error;

        if (alps_command_mode_write_reg(psmouse, 0x0151, 0x01))
                goto error;

        if (alps_command_mode_write_reg(psmouse, 0x0168, 0x03))
                goto error;

        if (alps_command_mode_write_reg(psmouse, 0x014a, 0x03))
                goto error;

        if (alps_command_mode_write_reg(psmouse, 0x0161, 0x03))
                goto error;

        alps_exit_command_mode(psmouse);

        /*
         * This sequence changes the output from a 9-byte to an
         * 8-byte format. All the same data seems to be present,
         * just in a more compact format.
         */
        param[0] = 0xc8;
        param[1] = 0x64;
        param[2] = 0x50;
        if (ps2_command(ps2dev, &param[0], PSMOUSE_CMD_SETRATE) ||
            ps2_command(ps2dev, &param[1], PSMOUSE_CMD_SETRATE) ||
            ps2_command(ps2dev, &param[2], PSMOUSE_CMD_SETRATE) ||
            ps2_command(ps2dev, param, PSMOUSE_CMD_GETID))
                return -1;

        /* Set rate and enable data reporting */
        param[0] = 0x64;
        if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE)) {
                psmouse_err(psmouse, "Failed to enable data reporting\n");
                return -1;
        }

        return 0;

error:
        /*
         * Leaving the touchpad in command mode will essentially render
         * it unusable until the machine reboots, so exit it here just
         * to be safe
         */
        alps_exit_command_mode(psmouse);
        return -1;
}

static int alps_get_otp_values_ss4_v2(struct psmouse *psmouse,
                                      unsigned char index, unsigned char otp[])
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;

        switch (index) {
        case 0:
                if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSTREAM)  ||
                    ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSTREAM)  ||
                    ps2_command(ps2dev, otp, PSMOUSE_CMD_GETINFO))
                        return -1;

                break;

        case 1:
                if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETPOLL)  ||
                    ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETPOLL)  ||
                    ps2_command(ps2dev, otp, PSMOUSE_CMD_GETINFO))
                        return -1;

                break;
        }

        return 0;
}

static int alps_update_device_area_ss4_v2(unsigned char otp[][4],
                                          struct alps_data *priv)
{
        int num_x_electrode;
        int num_y_electrode;
        int x_pitch, y_pitch, x_phys, y_phys;

        if (IS_SS4PLUS_DEV(priv->dev_id)) {
                num_x_electrode =
                        SS4PLUS_NUMSENSOR_XOFFSET + (otp[0][2] & 0x0F);
                num_y_electrode =
                        SS4PLUS_NUMSENSOR_YOFFSET + ((otp[0][2] >> 4) & 0x0F);

                priv->x_max =
                        (num_x_electrode - 1) * SS4PLUS_COUNT_PER_ELECTRODE;
                priv->y_max =
                        (num_y_electrode - 1) * SS4PLUS_COUNT_PER_ELECTRODE;

                x_pitch = (otp[0][1] & 0x0F) + SS4PLUS_MIN_PITCH_MM;
                y_pitch = ((otp[0][1] >> 4) & 0x0F) + SS4PLUS_MIN_PITCH_MM;

        } else {
                num_x_electrode =
                        SS4_NUMSENSOR_XOFFSET + (otp[1][0] & 0x0F);
                num_y_electrode =
                        SS4_NUMSENSOR_YOFFSET + ((otp[1][0] >> 4) & 0x0F);

                priv->x_max =
                        (num_x_electrode - 1) * SS4_COUNT_PER_ELECTRODE;
                priv->y_max =
                        (num_y_electrode - 1) * SS4_COUNT_PER_ELECTRODE;

                x_pitch = ((otp[1][2] >> 2) & 0x07) + SS4_MIN_PITCH_MM;
                y_pitch = ((otp[1][2] >> 5) & 0x07) + SS4_MIN_PITCH_MM;
        }

        x_phys = x_pitch * (num_x_electrode - 1); /* In 0.1 mm units */
        y_phys = y_pitch * (num_y_electrode - 1); /* In 0.1 mm units */

        priv->x_res = priv->x_max * 10 / x_phys; /* units / mm */
        priv->y_res = priv->y_max * 10 / y_phys; /* units / mm */

        return 0;
}

static int alps_update_btn_info_ss4_v2(unsigned char otp[][4],
                                       struct alps_data *priv)
{
        unsigned char is_btnless;

        if (IS_SS4PLUS_DEV(priv->dev_id))
                is_btnless = (otp[1][0] >> 1) & 0x01;
        else
                is_btnless = (otp[1][1] >> 3) & 0x01;

        if (is_btnless)
                priv->flags |= ALPS_BUTTONPAD;

        return 0;
}

static int alps_update_dual_info_ss4_v2(unsigned char otp[][4],
                                        struct alps_data *priv,
                                        struct psmouse *psmouse)
{
        bool is_dual = false;
        int reg_val = 0;
        struct ps2dev *ps2dev = &psmouse->ps2dev;

        if (IS_SS4PLUS_DEV(priv->dev_id)) {
                is_dual = (otp[0][0] >> 4) & 0x01;

                if (!is_dual) {
                        /* For support TrackStick of Thinkpad L/E series */
                        if (alps_exit_command_mode(psmouse) == 0 &&
                                alps_enter_command_mode(psmouse) == 0) {
                                reg_val = alps_command_mode_read_reg(psmouse,
                                                                        0xD7);
                        }
                        alps_exit_command_mode(psmouse);
                        ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE);

                        if (reg_val == 0x0C || reg_val == 0x1D)
                                is_dual = true;
                }
        }

        if (is_dual)
                priv->flags |= ALPS_DUALPOINT |
                                        ALPS_DUALPOINT_WITH_PRESSURE;

        return 0;
}

static int alps_set_defaults_ss4_v2(struct psmouse *psmouse,
                                    struct alps_data *priv)
{
        unsigned char otp[2][4];

        memset(otp, 0, sizeof(otp));

        if (alps_get_otp_values_ss4_v2(psmouse, 1, &otp[1][0]) ||
            alps_get_otp_values_ss4_v2(psmouse, 0, &otp[0][0]))
                return -1;

        alps_update_device_area_ss4_v2(otp, priv);

        alps_update_btn_info_ss4_v2(otp, priv);

        alps_update_dual_info_ss4_v2(otp, priv, psmouse);

        return 0;
}

static int alps_dolphin_get_device_area(struct psmouse *psmouse,
                                        struct alps_data *priv)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        unsigned char param[4] = {0};
        int num_x_electrode, num_y_electrode;

        if (alps_enter_command_mode(psmouse))
                return -1;

        param[0] = 0x0a;
        if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_WRAP) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETPOLL) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETPOLL) ||
            ps2_command(ps2dev, &param[0], PSMOUSE_CMD_SETRATE) ||
            ps2_command(ps2dev, &param[0], PSMOUSE_CMD_SETRATE))
                return -1;

        if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
                return -1;

        /*
         * Dolphin's sensor line number is not fixed. It can be calculated
         * by adding the device's register value with DOLPHIN_PROFILE_X/YOFFSET.
         * Further more, we can get device's x_max and y_max by multiplying
         * sensor line number with DOLPHIN_COUNT_PER_ELECTRODE.
         *
         * e.g. When we get register's sensor_x = 11 & sensor_y = 8,
         *      real sensor line number X = 11 + 8 = 19, and
         *      real sensor line number Y = 8 + 1 = 9.
         *      So, x_max = (19 - 1) * 64 = 1152, and
         *          y_max = (9 - 1) * 64 = 512.
         */
        num_x_electrode = DOLPHIN_PROFILE_XOFFSET + (param[2] & 0x0F);
        num_y_electrode = DOLPHIN_PROFILE_YOFFSET + ((param[2] >> 4) & 0x0F);
        priv->x_bits = num_x_electrode;
        priv->y_bits = num_y_electrode;
        priv->x_max = (num_x_electrode - 1) * DOLPHIN_COUNT_PER_ELECTRODE;
        priv->y_max = (num_y_electrode - 1) * DOLPHIN_COUNT_PER_ELECTRODE;

        if (alps_exit_command_mode(psmouse))
                return -1;

        return 0;
}

static int alps_hw_init_dolphin_v1(struct psmouse *psmouse)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        unsigned char param[2];

        /* This is dolphin "v1" as empirically defined by florin9doi */
        param[0] = 0x64;
        param[1] = 0x28;

        if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSTREAM) ||
            ps2_command(ps2dev, &param[0], PSMOUSE_CMD_SETRATE) ||
            ps2_command(ps2dev, &param[1], PSMOUSE_CMD_SETRATE))
                return -1;

        return 0;
}

static int alps_hw_init_v7(struct psmouse *psmouse)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        int reg_val, ret = -1;

        if (alps_enter_command_mode(psmouse) ||
            alps_command_mode_read_reg(psmouse, 0xc2d9) == -1)
                goto error;

        if (alps_get_v3_v7_resolution(psmouse, 0xc397))
                goto error;

        if (alps_command_mode_write_reg(psmouse, 0xc2c9, 0x64))
                goto error;

        reg_val = alps_command_mode_read_reg(psmouse, 0xc2c4);
        if (reg_val == -1)
                goto error;
        if (__alps_command_mode_write_reg(psmouse, reg_val | 0x02))
                goto error;

        alps_exit_command_mode(psmouse);
        return ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE);

error:
        alps_exit_command_mode(psmouse);
        return ret;
}

static int alps_hw_init_ss4_v2(struct psmouse *psmouse)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        char param[2] = {0x64, 0x28};
        int ret = -1;

        /* enter absolute mode */
        if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSTREAM) ||
            ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSTREAM) ||
            ps2_command(ps2dev, &param[0], PSMOUSE_CMD_SETRATE) ||
            ps2_command(ps2dev, &param[1], PSMOUSE_CMD_SETRATE)) {
                goto error;
        }

        /* T.B.D. Decread noise packet number, delete in the future */
        if (alps_exit_command_mode(psmouse) ||
            alps_enter_command_mode(psmouse) ||
            alps_command_mode_write_reg(psmouse, 0x001D, 0x20)) {
                goto error;
        }
        alps_exit_command_mode(psmouse);

        return ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE);

error:
        alps_exit_command_mode(psmouse);
        return ret;
}

static int alps_set_protocol(struct psmouse *psmouse,
                             struct alps_data *priv,
                             const struct alps_protocol_info *protocol)
{
        psmouse->private = priv;

        timer_setup(&priv->timer, alps_flush_packet, 0);

        priv->proto_version = protocol->version;
        priv->byte0 = protocol->byte0;
        priv->mask0 = protocol->mask0;
        priv->flags = protocol->flags;

        priv->x_max = 2000;
        priv->y_max = 1400;
        priv->x_bits = 15;
        priv->y_bits = 11;

        switch (priv->proto_version) {
        case ALPS_PROTO_V1:
        case ALPS_PROTO_V2:
                priv->hw_init = alps_hw_init_v1_v2;
                priv->process_packet = alps_process_packet_v1_v2;
                priv->set_abs_params = alps_set_abs_params_st;
                priv->x_max = 1023;
                priv->y_max = 767;
                if (dmi_check_system(alps_dmi_has_separate_stick_buttons))
                        priv->flags |= ALPS_STICK_BITS;
                break;

        case ALPS_PROTO_V3:
                priv->hw_init = alps_hw_init_v3;
                priv->process_packet = alps_process_packet_v3;
                priv->set_abs_params = alps_set_abs_params_semi_mt;
                priv->decode_fields = alps_decode_pinnacle;
                priv->nibble_commands = alps_v3_nibble_commands;
                priv->addr_command = PSMOUSE_CMD_RESET_WRAP;

                if (alps_probe_trackstick_v3_v7(psmouse,
                                                ALPS_REG_BASE_PINNACLE) < 0)
                        priv->flags &= ~ALPS_DUALPOINT;

                break;

        case ALPS_PROTO_V3_RUSHMORE:
                priv->hw_init = alps_hw_init_rushmore_v3;
                priv->process_packet = alps_process_packet_v3;
                priv->set_abs_params = alps_set_abs_params_semi_mt;
                priv->decode_fields = alps_decode_rushmore;
                priv->nibble_commands = alps_v3_nibble_commands;
                priv->addr_command = PSMOUSE_CMD_RESET_WRAP;
                priv->x_bits = 16;
                priv->y_bits = 12;

                if (alps_probe_trackstick_v3_v7(psmouse,
                                                ALPS_REG_BASE_RUSHMORE) < 0)
                        priv->flags &= ~ALPS_DUALPOINT;

                break;

        case ALPS_PROTO_V4:
                priv->hw_init = alps_hw_init_v4;
                priv->process_packet = alps_process_packet_v4;
                priv->set_abs_params = alps_set_abs_params_semi_mt;
                priv->nibble_commands = alps_v4_nibble_commands;
                priv->addr_command = PSMOUSE_CMD_DISABLE;
                break;

        case ALPS_PROTO_V5:
                priv->hw_init = alps_hw_init_dolphin_v1;
                priv->process_packet = alps_process_touchpad_packet_v3_v5;
                priv->decode_fields = alps_decode_dolphin;
                priv->set_abs_params = alps_set_abs_params_semi_mt;
                priv->nibble_commands = alps_v3_nibble_commands;
                priv->addr_command = PSMOUSE_CMD_RESET_WRAP;
                priv->x_bits = 23;
                priv->y_bits = 12;

                if (alps_dolphin_get_device_area(psmouse, priv))
                        return -EIO;

                break;

        case ALPS_PROTO_V6:
                priv->hw_init = alps_hw_init_v6;
                priv->process_packet = alps_process_packet_v6;
                priv->set_abs_params = alps_set_abs_params_st;
                priv->nibble_commands = alps_v6_nibble_commands;
                priv->x_max = 2047;
                priv->y_max = 1535;
                break;

        case ALPS_PROTO_V7:
                priv->hw_init = alps_hw_init_v7;
                priv->process_packet = alps_process_packet_v7;
                priv->decode_fields = alps_decode_packet_v7;
                priv->set_abs_params = alps_set_abs_params_v7;
                priv->nibble_commands = alps_v3_nibble_commands;
                priv->addr_command = PSMOUSE_CMD_RESET_WRAP;
                priv->x_max = 0xfff;
                priv->y_max = 0x7ff;

                if (priv->fw_ver[1] != 0xba)
                        priv->flags |= ALPS_BUTTONPAD;

                if (alps_probe_trackstick_v3_v7(psmouse, ALPS_REG_BASE_V7) < 0)
                        priv->flags &= ~ALPS_DUALPOINT;

                break;

        case ALPS_PROTO_V8:
                priv->hw_init = alps_hw_init_ss4_v2;
                priv->process_packet = alps_process_packet_ss4_v2;
                priv->decode_fields = alps_decode_ss4_v2;
                priv->set_abs_params = alps_set_abs_params_ss4_v2;
                priv->nibble_commands = alps_v3_nibble_commands;
                priv->addr_command = PSMOUSE_CMD_RESET_WRAP;

                if (alps_set_defaults_ss4_v2(psmouse, priv))
                        return -EIO;

                break;
        }

        return 0;
}

static const struct alps_protocol_info *alps_match_table(unsigned char *e7,
                                                         unsigned char *ec)
{
        const struct alps_model_info *model;
        int i;

        for (i = 0; i < ARRAY_SIZE(alps_model_data); i++) {
                model = &alps_model_data[i];

                if (!memcmp(e7, model->signature, sizeof(model->signature)))
                        return &model->protocol_info;
        }

        return NULL;
}

static bool alps_is_cs19_trackpoint(struct psmouse *psmouse)
{
        u8 param[2] = { 0 };

        if (ps2_command(&psmouse->ps2dev,
                        param, MAKE_PS2_CMD(0, 2, TP_READ_ID)))
                return false;

        /*
         * param[0] contains the trackpoint device variant_id while
         * param[1] contains the firmware_id. So far all alps
         * trackpoint-only devices have their variant_ids equal
         * TP_VARIANT_ALPS and their firmware_ids are in 0x20~0x2f range.
         */
        return param[0] == TP_VARIANT_ALPS && ((param[1] & 0xf0) == 0x20);
}

static int alps_identify(struct psmouse *psmouse, struct alps_data *priv)
{
        const struct alps_protocol_info *protocol;
        unsigned char e6[4], e7[4], ec[4];
        int error;

        /*
         * First try "E6 report".
         * ALPS should return 0,0,10 or 0,0,100 if no buttons are pressed.
         * The bits 0-2 of the first byte will be 1s if some buttons are
         * pressed.
         */
        if (alps_rpt_cmd(psmouse, PSMOUSE_CMD_SETRES,
                         PSMOUSE_CMD_SETSCALE11, e6))
                return -EIO;

        if ((e6[0] & 0xf8) != 0 || e6[1] != 0 || (e6[2] != 10 && e6[2] != 100))
                return -EINVAL;

        /*
         * Now get the "E7" and "EC" reports.  These will uniquely identify
         * most ALPS touchpads.
         */
        if (alps_rpt_cmd(psmouse, PSMOUSE_CMD_SETRES,
                         PSMOUSE_CMD_SETSCALE21, e7) ||
            alps_rpt_cmd(psmouse, PSMOUSE_CMD_SETRES,
                         PSMOUSE_CMD_RESET_WRAP, ec) ||
            alps_exit_command_mode(psmouse))
                return -EIO;

        protocol = alps_match_table(e7, ec);
        if (!protocol) {
                if (e7[0] == 0x73 && e7[1] == 0x02 && e7[2] == 0x64 &&
                           ec[2] == 0x8a) {
                        protocol = &alps_v4_protocol_data;
                } else if (e7[0] == 0x73 && e7[1] == 0x03 && e7[2] == 0x50 &&
                           ec[0] == 0x73 && (ec[1] == 0x01 || ec[1] == 0x02)) {
                        protocol = &alps_v5_protocol_data;
                } else if (ec[0] == 0x88 &&
                           ((ec[1] & 0xf0) == 0xb0 || (ec[1] & 0xf0) == 0xc0)) {
                        protocol = &alps_v7_protocol_data;
                } else if (ec[0] == 0x88 && ec[1] == 0x08) {
                        protocol = &alps_v3_rushmore_data;
                } else if (ec[0] == 0x88 && ec[1] == 0x07 &&
                           ec[2] >= 0x90 && ec[2] <= 0x9d) {
                        protocol = &alps_v3_protocol_data;
                } else if (e7[0] == 0x73 && e7[1] == 0x03 &&
                           (e7[2] == 0x14 || e7[2] == 0x28)) {
                        protocol = &alps_v8_protocol_data;
                } else if (e7[0] == 0x73 && e7[1] == 0x03 && e7[2] == 0xc8) {
                        protocol = &alps_v9_protocol_data;
                        psmouse_warn(psmouse,
                                     "Unsupported ALPS V9 touchpad: E7=%3ph, EC=%3ph\n",
                                     e7, ec);
                        return -EINVAL;
                } else {
                        psmouse_dbg(psmouse,
                                    "Likely not an ALPS touchpad: E7=%3ph, EC=%3ph\n", e7, ec);
                        return -EINVAL;
                }
        }

        if (priv) {
                /* Save Device ID and Firmware version */
                memcpy(priv->dev_id, e7, 3);
                memcpy(priv->fw_ver, ec, 3);
                error = alps_set_protocol(psmouse, priv, protocol);
                if (error)
                        return error;
        }

        return 0;
}

static int alps_reconnect(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;

        psmouse_reset(psmouse);

        if (alps_identify(psmouse, priv) < 0)
                return -1;

        return priv->hw_init(psmouse);
}

static void alps_disconnect(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;

        psmouse_reset(psmouse);
        timer_shutdown_sync(&priv->timer);
        disable_delayed_work_sync(&priv->dev3_register_work);
        if (priv->dev2)
                input_unregister_device(priv->dev2);
        if (!IS_ERR_OR_NULL(priv->dev3))
                input_unregister_device(priv->dev3);
        kfree(priv);
}

static void alps_set_abs_params_st(struct alps_data *priv,
                                   struct input_dev *dev1)
{
        input_set_abs_params(dev1, ABS_X, 0, priv->x_max, 0, 0);
        input_set_abs_params(dev1, ABS_Y, 0, priv->y_max, 0, 0);
        input_set_abs_params(dev1, ABS_PRESSURE, 0, 127, 0, 0);
}

static void alps_set_abs_params_mt_common(struct alps_data *priv,
                                          struct input_dev *dev1)
{
        input_set_abs_params(dev1, ABS_MT_POSITION_X, 0, priv->x_max, 0, 0);
        input_set_abs_params(dev1, ABS_MT_POSITION_Y, 0, priv->y_max, 0, 0);

        input_abs_set_res(dev1, ABS_MT_POSITION_X, priv->x_res);
        input_abs_set_res(dev1, ABS_MT_POSITION_Y, priv->y_res);

        set_bit(BTN_TOOL_TRIPLETAP, dev1->keybit);
        set_bit(BTN_TOOL_QUADTAP, dev1->keybit);
}

static void alps_set_abs_params_semi_mt(struct alps_data *priv,
                                        struct input_dev *dev1)
{
        alps_set_abs_params_mt_common(priv, dev1);
        input_set_abs_params(dev1, ABS_PRESSURE, 0, 127, 0, 0);

        input_mt_init_slots(dev1, MAX_TOUCHES,
                            INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED |
                                INPUT_MT_SEMI_MT);
}

static void alps_set_abs_params_v7(struct alps_data *priv,
                                   struct input_dev *dev1)
{
        alps_set_abs_params_mt_common(priv, dev1);
        set_bit(BTN_TOOL_QUINTTAP, dev1->keybit);

        input_mt_init_slots(dev1, MAX_TOUCHES,
                            INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED |
                                INPUT_MT_TRACK);

        set_bit(BTN_TOOL_QUINTTAP, dev1->keybit);
}

static void alps_set_abs_params_ss4_v2(struct alps_data *priv,
                                       struct input_dev *dev1)
{
        alps_set_abs_params_mt_common(priv, dev1);
        input_set_abs_params(dev1, ABS_PRESSURE, 0, 127, 0, 0);
        set_bit(BTN_TOOL_QUINTTAP, dev1->keybit);

        input_mt_init_slots(dev1, MAX_TOUCHES,
                            INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED |
                                INPUT_MT_TRACK);
}

int alps_init(struct psmouse *psmouse)
{
        struct alps_data *priv = psmouse->private;
        struct input_dev *dev1 = psmouse->dev;
        int error;

        error = priv->hw_init(psmouse);
        if (error)
                goto init_fail;

        /*
         * Undo part of setup done for us by psmouse core since touchpad
         * is not a relative device.
         */
        __clear_bit(EV_REL, dev1->evbit);
        __clear_bit(REL_X, dev1->relbit);
        __clear_bit(REL_Y, dev1->relbit);

        /*
         * Now set up our capabilities.
         */
        dev1->evbit[BIT_WORD(EV_KEY)] |= BIT_MASK(EV_KEY);
        dev1->keybit[BIT_WORD(BTN_TOUCH)] |= BIT_MASK(BTN_TOUCH);
        dev1->keybit[BIT_WORD(BTN_TOOL_FINGER)] |= BIT_MASK(BTN_TOOL_FINGER);
        dev1->keybit[BIT_WORD(BTN_LEFT)] |=
                BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_RIGHT);

        dev1->evbit[BIT_WORD(EV_ABS)] |= BIT_MASK(EV_ABS);

        priv->set_abs_params(priv, dev1);

        if (priv->flags & ALPS_WHEEL) {
                dev1->evbit[BIT_WORD(EV_REL)] |= BIT_MASK(EV_REL);
                dev1->relbit[BIT_WORD(REL_WHEEL)] |= BIT_MASK(REL_WHEEL);
        }

        if (priv->flags & (ALPS_FW_BK_1 | ALPS_FW_BK_2)) {
                dev1->keybit[BIT_WORD(BTN_FORWARD)] |= BIT_MASK(BTN_FORWARD);
                dev1->keybit[BIT_WORD(BTN_BACK)] |= BIT_MASK(BTN_BACK);
        }

        if (priv->flags & ALPS_FOUR_BUTTONS) {
                dev1->keybit[BIT_WORD(BTN_0)] |= BIT_MASK(BTN_0);
                dev1->keybit[BIT_WORD(BTN_1)] |= BIT_MASK(BTN_1);
                dev1->keybit[BIT_WORD(BTN_2)] |= BIT_MASK(BTN_2);
                dev1->keybit[BIT_WORD(BTN_3)] |= BIT_MASK(BTN_3);
        } else if (priv->flags & ALPS_BUTTONPAD) {
                set_bit(INPUT_PROP_BUTTONPAD, dev1->propbit);
                clear_bit(BTN_RIGHT, dev1->keybit);
        } else {
                dev1->keybit[BIT_WORD(BTN_MIDDLE)] |= BIT_MASK(BTN_MIDDLE);
        }

        if (priv->flags & ALPS_DUALPOINT) {
                struct input_dev *dev2;

                dev2 = input_allocate_device();
                if (!dev2) {
                        psmouse_err(psmouse,
                                    "failed to allocate trackstick device\n");
                        error = -ENOMEM;
                        goto init_fail;
                }

                scnprintf(priv->phys2, sizeof(priv->phys2), "%s/input1",
                          psmouse->ps2dev.serio->phys);
                dev2->phys = priv->phys2;

                /*
                 * format of input device name is: "protocol vendor name"
                 * see function psmouse_switch_protocol() in psmouse-base.c
                 */
                dev2->name = "AlpsPS/2 ALPS DualPoint Stick";

                dev2->id.bustype = BUS_I8042;
                dev2->id.vendor  = 0x0002;
                dev2->id.product = PSMOUSE_ALPS;
                dev2->id.version = priv->proto_version;
                dev2->dev.parent = &psmouse->ps2dev.serio->dev;

                input_set_capability(dev2, EV_REL, REL_X);
                input_set_capability(dev2, EV_REL, REL_Y);
                if (priv->flags & ALPS_DUALPOINT_WITH_PRESSURE) {
                        input_set_capability(dev2, EV_ABS, ABS_PRESSURE);
                        input_set_abs_params(dev2, ABS_PRESSURE, 0, 127, 0, 0);
                }
                input_set_capability(dev2, EV_KEY, BTN_LEFT);
                input_set_capability(dev2, EV_KEY, BTN_RIGHT);
                input_set_capability(dev2, EV_KEY, BTN_MIDDLE);

                __set_bit(INPUT_PROP_POINTER, dev2->propbit);
                __set_bit(INPUT_PROP_POINTING_STICK, dev2->propbit);

                error = input_register_device(dev2);
                if (error) {
                        psmouse_err(psmouse,
                                    "failed to register trackstick device: %d\n",
                                    error);
                        input_free_device(dev2);
                        goto init_fail;
                }

                priv->dev2 = dev2;
        }

        priv->psmouse = psmouse;

        INIT_DELAYED_WORK(&priv->dev3_register_work,
                          alps_register_bare_ps2_mouse);

        psmouse->protocol_handler = alps_process_byte;
        psmouse->poll = alps_poll;
        psmouse->disconnect = alps_disconnect;
        psmouse->reconnect = alps_reconnect;
        psmouse->pktsize = priv->proto_version == ALPS_PROTO_V4 ? 8 : 6;

        /* We are having trouble resyncing ALPS touchpads so disable it for now */
        psmouse->resync_time = 0;

        /* Allow 2 invalid packets without resetting device */
        psmouse->resetafter = psmouse->pktsize * 2;

        return 0;

init_fail:
        psmouse_reset(psmouse);
        /*
         * Even though we did not allocate psmouse->private we do free
         * it here.
         */
        kfree(psmouse->private);
        psmouse->private = NULL;
        return error;
}

int alps_detect(struct psmouse *psmouse, bool set_properties)
{
        struct alps_data *priv;
        int error;

        error = alps_identify(psmouse, NULL);
        if (error)
                return error;

        /*
         * ALPS cs19 is a trackpoint-only device, and uses different
         * protocol than DualPoint ones, so we return -EINVAL here and let
         * trackpoint.c drive this device. If the trackpoint driver is not
         * enabled, the device will fall back to a bare PS/2 mouse.
         * If ps2_command() fails here, we depend on the immediately
         * followed psmouse_reset() to reset the device to normal state.
         */
        if (alps_is_cs19_trackpoint(psmouse)) {
                psmouse_dbg(psmouse,
                            "ALPS CS19 trackpoint-only device detected, ignoring\n");
                return -EINVAL;
        }

        /*
         * Reset the device to make sure it is fully operational:
         * on some laptops, like certain Dell Latitudes, we may
         * fail to properly detect presence of trackstick if device
         * has not been reset.
         */
        psmouse_reset(psmouse);

        priv = kzalloc_obj(*priv);
        if (!priv)
                return -ENOMEM;

        error = alps_identify(psmouse, priv);
        if (error) {
                kfree(priv);
                return error;
        }

        if (set_properties) {
                psmouse->vendor = "ALPS";
                psmouse->name = priv->flags & ALPS_DUALPOINT ?
                                "DualPoint TouchPad" : "GlidePoint";
                psmouse->model = priv->proto_version;
        } else {
                /*
                 * Destroy alps_data structure we allocated earlier since
                 * this was just a "trial run". Otherwise we'll keep it
                 * to be used by alps_init() which has to be called if
                 * we succeed and set_properties is true.
                 */
                kfree(priv);
                psmouse->private = NULL;
        }

        return 0;
}