// SPDX-License-Identifier: GPL-2.0-only
/*
 * PS/2 mouse driver
 *
 * Copyright (c) 1999-2002 Vojtech Pavlik
 * Copyright (c) 2003-2004 Dmitry Torokhov
 */


#define pr_fmt(fmt)             KBUILD_MODNAME ": " fmt
#define psmouse_fmt(fmt)        fmt

#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/init.h>
#include <linux/libps2.h>
#include <linux/mutex.h>
#include <linux/types.h>

#include "psmouse.h"
#include "synaptics.h"
#include "logips2pp.h"
#include "alps.h"
#include "hgpk.h"
#include "lifebook.h"
#include "trackpoint.h"
#include "touchkit_ps2.h"
#include "elantech.h"
#include "sentelic.h"
#include "cypress_ps2.h"
#include "focaltech.h"
#include "vmmouse.h"
#include "byd.h"

#define DRIVER_DESC     "PS/2 mouse driver"

MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

static unsigned int psmouse_max_proto = PSMOUSE_AUTO;
static int psmouse_set_maxproto(const char *val, const struct kernel_param *);
static int psmouse_get_maxproto(char *buffer, const struct kernel_param *kp);
static const struct kernel_param_ops param_ops_proto_abbrev = {
        .set = psmouse_set_maxproto,
        .get = psmouse_get_maxproto,
};
#define param_check_proto_abbrev(name, p)       __param_check(name, p, unsigned int)
module_param_named(proto, psmouse_max_proto, proto_abbrev, 0644);
MODULE_PARM_DESC(proto, "Highest protocol extension to probe (bare, imps, exps, any). Useful for KVM switches.");

static unsigned int psmouse_resolution = 200;
module_param_named(resolution, psmouse_resolution, uint, 0644);
MODULE_PARM_DESC(resolution, "Resolution, in dpi.");

static unsigned int psmouse_rate = 100;
module_param_named(rate, psmouse_rate, uint, 0644);
MODULE_PARM_DESC(rate, "Report rate, in reports per second.");

static bool psmouse_smartscroll = true;
module_param_named(smartscroll, psmouse_smartscroll, bool, 0644);
MODULE_PARM_DESC(smartscroll, "Logitech Smartscroll autorepeat, 1 = enabled (default), 0 = disabled.");

static bool psmouse_a4tech_2wheels;
module_param_named(a4tech_workaround, psmouse_a4tech_2wheels, bool, 0644);
MODULE_PARM_DESC(a4tech_workaround, "A4Tech second scroll wheel workaround, 1 = enabled, 0 = disabled (default).");

static unsigned int psmouse_resetafter = 5;
module_param_named(resetafter, psmouse_resetafter, uint, 0644);
MODULE_PARM_DESC(resetafter, "Reset device after so many bad packets (0 = never).");

static unsigned int psmouse_resync_time;
module_param_named(resync_time, psmouse_resync_time, uint, 0644);
MODULE_PARM_DESC(resync_time, "How long can mouse stay idle before forcing resync (in seconds, 0 = never).");

PSMOUSE_DEFINE_ATTR(protocol, S_IWUSR | S_IRUGO,
                        NULL,
                        psmouse_attr_show_protocol, psmouse_attr_set_protocol);
PSMOUSE_DEFINE_ATTR(rate, S_IWUSR | S_IRUGO,
                        (void *) offsetof(struct psmouse, rate),
                        psmouse_show_int_attr, psmouse_attr_set_rate);
PSMOUSE_DEFINE_ATTR(resolution, S_IWUSR | S_IRUGO,
                        (void *) offsetof(struct psmouse, resolution),
                        psmouse_show_int_attr, psmouse_attr_set_resolution);
PSMOUSE_DEFINE_ATTR(resetafter, S_IWUSR | S_IRUGO,
                        (void *) offsetof(struct psmouse, resetafter),
                        psmouse_show_int_attr, psmouse_set_int_attr);
PSMOUSE_DEFINE_ATTR(resync_time, S_IWUSR | S_IRUGO,
                        (void *) offsetof(struct psmouse, resync_time),
                        psmouse_show_int_attr, psmouse_set_int_attr);

static struct attribute *psmouse_attributes[] = {
        &psmouse_attr_protocol.dattr.attr,
        &psmouse_attr_rate.dattr.attr,
        &psmouse_attr_resolution.dattr.attr,
        &psmouse_attr_resetafter.dattr.attr,
        &psmouse_attr_resync_time.dattr.attr,
        NULL
};

static const struct attribute_group psmouse_attribute_group = {
        .attrs  = psmouse_attributes,
};

/*
 * psmouse_mutex protects all operations changing state of mouse
 * (connecting, disconnecting, changing rate or resolution via
 * sysfs). We could use a per-device semaphore but since there
 * rarely more than one PS/2 mouse connected and since semaphore
 * is taken in "slow" paths it is not worth it.
 */
static DEFINE_MUTEX(psmouse_mutex);

static struct workqueue_struct *kpsmoused_wq;

void psmouse_report_standard_buttons(struct input_dev *dev, u8 buttons)
{
        input_report_key(dev, BTN_LEFT,   buttons & BIT(0));
        input_report_key(dev, BTN_MIDDLE, buttons & BIT(2));
        input_report_key(dev, BTN_RIGHT,  buttons & BIT(1));
}

void psmouse_report_standard_motion(struct input_dev *dev, u8 *packet)
{
        int x, y;

        x = packet[1] ? packet[1] - ((packet[0] << 4) & 0x100) : 0;
        y = packet[2] ? packet[2] - ((packet[0] << 3) & 0x100) : 0;

        input_report_rel(dev, REL_X, x);
        input_report_rel(dev, REL_Y, -y);
}

void psmouse_report_standard_packet(struct input_dev *dev, u8 *packet)
{
        psmouse_report_standard_buttons(dev, packet[0]);
        psmouse_report_standard_motion(dev, packet);
}

/*
 * psmouse_process_byte() analyzes the PS/2 data stream and reports
 * relevant events to the input module once full packet has arrived.
 */
psmouse_ret_t psmouse_process_byte(struct psmouse *psmouse)
{
        struct input_dev *dev = psmouse->dev;
        u8 *packet = psmouse->packet;
        int wheel;

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

        /* Full packet accumulated, process it */

        switch (psmouse->protocol->type) {
        case PSMOUSE_IMPS:
                /* IntelliMouse has scroll wheel */
                input_report_rel(dev, REL_WHEEL, -(s8) packet[3]);
                break;

        case PSMOUSE_IMEX:
                /* Scroll wheel and buttons on IntelliMouse Explorer */
                switch (packet[3] & 0xC0) {
                case 0x80: /* vertical scroll on IntelliMouse Explorer 4.0 */
                        input_report_rel(dev, REL_WHEEL,
                                         -sign_extend32(packet[3], 5));
                        break;
                case 0x40: /* horizontal scroll on IntelliMouse Explorer 4.0 */
                        input_report_rel(dev, REL_HWHEEL,
                                         -sign_extend32(packet[3], 5));
                        break;
                case 0x00:
                case 0xC0:
                        wheel = sign_extend32(packet[3], 3);

                        /*
                         * Some A4Tech mice have two scroll wheels, with first
                         * one reporting +/-1 in the lower nibble, and second
                         * one reporting +/-2.
                         */
                        if (psmouse_a4tech_2wheels && abs(wheel) > 1)
                                input_report_rel(dev, REL_HWHEEL, wheel / 2);
                        else
                                input_report_rel(dev, REL_WHEEL, -wheel);

                        input_report_key(dev, BTN_SIDE,  packet[3] & BIT(4));
                        input_report_key(dev, BTN_EXTRA, packet[3] & BIT(5));
                        break;
                }
                break;

        case PSMOUSE_GENPS:
                /* Report scroll buttons on NetMice */
                input_report_rel(dev, REL_WHEEL, -(s8) packet[3]);

                /* Extra buttons on Genius NewNet 3D */
                input_report_key(dev, BTN_SIDE,  packet[0] & BIT(6));
                input_report_key(dev, BTN_EXTRA, packet[0] & BIT(7));
                break;

        case PSMOUSE_THINKPS:
                /* Extra button on ThinkingMouse */
                input_report_key(dev, BTN_EXTRA, packet[0] & BIT(3));

                /*
                 * Without this bit of weirdness moving up gives wildly
                 * high Y changes.
                 */
                packet[1] |= (packet[0] & 0x40) << 1;
                break;

        case PSMOUSE_CORTRON:
                /*
                 * Cortron PS2 Trackball reports SIDE button in the
                 * 4th bit of the first byte.
                 */
                input_report_key(dev, BTN_SIDE, packet[0] & BIT(3));
                packet[0] |= BIT(3);
                break;

        default:
                break;
        }

        /* Generic PS/2 Mouse */
        packet[0] |= psmouse->extra_buttons;
        psmouse_report_standard_packet(dev, packet);

        input_sync(dev);

        return PSMOUSE_FULL_PACKET;
}

void psmouse_queue_work(struct psmouse *psmouse, struct delayed_work *work,
                unsigned long delay)
{
        queue_delayed_work(kpsmoused_wq, work, delay);
}

/*
 * __psmouse_set_state() sets new psmouse state and resets all flags.
 */
static inline void __psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state)
{
        psmouse->state = new_state;
        psmouse->pktcnt = psmouse->out_of_sync_cnt = 0;
        psmouse->ps2dev.flags = 0;
        psmouse->last = jiffies;
}

/*
 * psmouse_set_state() sets new psmouse state and resets all flags and
 * counters while holding serio lock so fighting with interrupt handler
 * is not a concern.
 */
void psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state)
{
        serio_pause_rx(psmouse->ps2dev.serio);
        __psmouse_set_state(psmouse, new_state);
        serio_continue_rx(psmouse->ps2dev.serio);
}

/*
 * psmouse_handle_byte() processes one byte of the input data stream
 * by calling corresponding protocol handler.
 */
static int psmouse_handle_byte(struct psmouse *psmouse)
{
        psmouse_ret_t rc = psmouse->protocol_handler(psmouse);

        switch (rc) {
        case PSMOUSE_BAD_DATA:
                if (psmouse->state == PSMOUSE_ACTIVATED) {
                        psmouse_warn(psmouse,
                                     "%s at %s lost sync at byte %d\n",
                                     psmouse->name, psmouse->phys,
                                     psmouse->pktcnt);
                        if (++psmouse->out_of_sync_cnt == psmouse->resetafter) {
                                __psmouse_set_state(psmouse, PSMOUSE_IGNORE);
                                psmouse_notice(psmouse,
                                                "issuing reconnect request\n");
                                serio_reconnect(psmouse->ps2dev.serio);
                                return -EIO;
                        }
                }
                psmouse->pktcnt = 0;
                break;

        case PSMOUSE_FULL_PACKET:
                psmouse->pktcnt = 0;
                if (psmouse->out_of_sync_cnt) {
                        psmouse->out_of_sync_cnt = 0;
                        psmouse_notice(psmouse,
                                        "%s at %s - driver resynced.\n",
                                        psmouse->name, psmouse->phys);
                }
                break;

        case PSMOUSE_GOOD_DATA:
                break;
        }
        return 0;
}

static void psmouse_handle_oob_data(struct psmouse *psmouse, u8 data)
{
        switch (psmouse->oob_data_type) {
        case PSMOUSE_OOB_NONE:
                psmouse->oob_data_type = data;
                break;

        case PSMOUSE_OOB_EXTRA_BTNS:
                psmouse_report_standard_buttons(psmouse->dev, data);
                input_sync(psmouse->dev);

                psmouse->extra_buttons = data;
                psmouse->oob_data_type = PSMOUSE_OOB_NONE;
                break;

        default:
                psmouse_warn(psmouse,
                             "unknown OOB_DATA type: 0x%02x\n",
                             psmouse->oob_data_type);
                psmouse->oob_data_type = PSMOUSE_OOB_NONE;
                break;
        }
}

/*
 * psmouse_interrupt() handles incoming characters, either passing them
 * for normal processing or gathering them as command response.
 */
static irqreturn_t psmouse_interrupt(struct serio *serio,
                                     u8 data, unsigned int flags)
{
        struct psmouse *psmouse = serio_get_drvdata(serio);

        if (psmouse->state == PSMOUSE_IGNORE)
                goto out;

        if (unlikely((flags & SERIO_TIMEOUT) ||
                     ((flags & SERIO_PARITY) &&
                      !psmouse->protocol->ignore_parity))) {

                if (psmouse->state == PSMOUSE_ACTIVATED)
                        psmouse_warn(psmouse,
                                     "bad data from KBC -%s%s\n",
                                     flags & SERIO_TIMEOUT ? " timeout" : "",
                                     flags & SERIO_PARITY ? " bad parity" : "");
                ps2_cmd_aborted(&psmouse->ps2dev);
                goto out;
        }

        if (flags & SERIO_OOB_DATA) {
                psmouse_handle_oob_data(psmouse, data);
                goto out;
        }

        if (unlikely(psmouse->ps2dev.flags & PS2_FLAG_ACK))
                if  (ps2_handle_ack(&psmouse->ps2dev, data))
                        goto out;

        if (unlikely(psmouse->ps2dev.flags & PS2_FLAG_CMD))
                if  (ps2_handle_response(&psmouse->ps2dev, data))
                        goto out;

        pm_wakeup_event(&serio->dev, 0);

        if (psmouse->state <= PSMOUSE_RESYNCING)
                goto out;

        if (psmouse->state == PSMOUSE_ACTIVATED &&
            psmouse->pktcnt && time_after(jiffies, psmouse->last + HZ/2)) {
                psmouse_info(psmouse, "%s at %s lost synchronization, throwing %d bytes away.\n",
                             psmouse->name, psmouse->phys, psmouse->pktcnt);
                psmouse->badbyte = psmouse->packet[0];
                __psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
                psmouse_queue_work(psmouse, &psmouse->resync_work, 0);
                goto out;
        }

        psmouse->packet[psmouse->pktcnt++] = data;

        /* Check if this is a new device announcement (0xAA 0x00) */
        if (unlikely(psmouse->packet[0] == PSMOUSE_RET_BAT && psmouse->pktcnt <= 2)) {
                if (psmouse->pktcnt == 1) {
                        psmouse->last = jiffies;
                        goto out;
                }

                if (psmouse->packet[1] == PSMOUSE_RET_ID ||
                    (psmouse->protocol->type == PSMOUSE_HGPK &&
                     psmouse->packet[1] == PSMOUSE_RET_BAT)) {
                        __psmouse_set_state(psmouse, PSMOUSE_IGNORE);
                        serio_reconnect(serio);
                        goto out;
                }

                /* Not a new device, try processing first byte normally */
                psmouse->pktcnt = 1;
                if (psmouse_handle_byte(psmouse))
                        goto out;

                psmouse->packet[psmouse->pktcnt++] = data;
        }

        /*
         * See if we need to force resync because mouse was idle for
         * too long.
         */
        if (psmouse->state == PSMOUSE_ACTIVATED &&
            psmouse->pktcnt == 1 && psmouse->resync_time &&
            time_after(jiffies, psmouse->last + psmouse->resync_time * HZ)) {
                psmouse->badbyte = psmouse->packet[0];
                __psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
                psmouse_queue_work(psmouse, &psmouse->resync_work, 0);
                goto out;
        }

        psmouse->last = jiffies;
        psmouse_handle_byte(psmouse);

 out:
        return IRQ_HANDLED;
}

/*
 * psmouse_reset() resets the mouse into power-on state.
 */
int psmouse_reset(struct psmouse *psmouse)
{
        u8 param[2];
        int error;

        error = ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_RESET_BAT);
        if (error)
                return error;

        if (param[0] != PSMOUSE_RET_BAT && param[1] != PSMOUSE_RET_ID)
                return -EIO;

        return 0;
}

/*
 * Here we set the mouse resolution.
 */
void psmouse_set_resolution(struct psmouse *psmouse, unsigned int resolution)
{
        static const u8 params[] = { 0, 1, 2, 2, 3 };
        u8 p;

        if (resolution == 0 || resolution > 200)
                resolution = 200;

        p = params[resolution / 50];
        ps2_command(&psmouse->ps2dev, &p, PSMOUSE_CMD_SETRES);
        psmouse->resolution = 25 << p;
}

/*
 * Here we set the mouse report rate.
 */
static void psmouse_set_rate(struct psmouse *psmouse, unsigned int rate)
{
        static const u8 rates[] = { 200, 100, 80, 60, 40, 20, 10, 0 };
        u8 r;
        int i = 0;

        while (rates[i] > rate)
                i++;
        r = rates[i];
        ps2_command(&psmouse->ps2dev, &r, PSMOUSE_CMD_SETRATE);
        psmouse->rate = r;
}

/*
 * Here we set the mouse scaling.
 */
static void psmouse_set_scale(struct psmouse *psmouse, enum psmouse_scale scale)
{
        ps2_command(&psmouse->ps2dev, NULL,
                    scale == PSMOUSE_SCALE21 ? PSMOUSE_CMD_SETSCALE21 :
                                               PSMOUSE_CMD_SETSCALE11);
}

/*
 * psmouse_poll() - default poll handler. Everyone except for ALPS uses it.
 */
static int psmouse_poll(struct psmouse *psmouse)
{
        return ps2_command(&psmouse->ps2dev, psmouse->packet,
                           PSMOUSE_CMD_POLL | (psmouse->pktsize << 8));
}

static bool psmouse_check_pnp_id(const char *id, const char * const ids[])
{
        int i;

        for (i = 0; ids[i]; i++)
                if (!strcasecmp(id, ids[i]))
                        return true;

        return false;
}

/*
 * psmouse_matches_pnp_id - check if psmouse matches one of the passed in ids.
 */
bool psmouse_matches_pnp_id(struct psmouse *psmouse, const char * const ids[])
{
        struct serio *serio = psmouse->ps2dev.serio;
        char *p, *fw_id_copy, *save_ptr;
        bool found = false;

        if (strncmp(serio->firmware_id, "PNP: ", 5))
                return false;

        fw_id_copy = kstrndup(&serio->firmware_id[5],
                              sizeof(serio->firmware_id) - 5,
                              GFP_KERNEL);
        if (!fw_id_copy)
                return false;

        save_ptr = fw_id_copy;
        while ((p = strsep(&fw_id_copy, " ")) != NULL) {
                if (psmouse_check_pnp_id(p, ids)) {
                        found = true;
                        break;
                }
        }

        kfree(save_ptr);
        return found;
}

/*
 * Genius NetMouse magic init.
 */
static int genius_detect(struct psmouse *psmouse, bool set_properties)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        u8 param[4];

        param[0] = 3;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
        ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11);
        ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11);
        ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11);
        ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO);

        if (param[0] != 0x00 || param[1] != 0x33 || param[2] != 0x55)
                return -ENODEV;

        if (set_properties) {
                __set_bit(BTN_MIDDLE, psmouse->dev->keybit);
                __set_bit(BTN_EXTRA, psmouse->dev->keybit);
                __set_bit(BTN_SIDE, psmouse->dev->keybit);
                __set_bit(REL_WHEEL, psmouse->dev->relbit);

                psmouse->vendor = "Genius";
                psmouse->name = "Mouse";
                psmouse->pktsize = 4;
        }

        return 0;
}

/*
 * IntelliMouse magic init.
 */
static int intellimouse_detect(struct psmouse *psmouse, bool set_properties)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        u8 param[2];

        param[0] = 200;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
        param[0] = 100;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
        param[0] =  80;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
        ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);

        if (param[0] != 3)
                return -ENODEV;

        if (set_properties) {
                __set_bit(BTN_MIDDLE, psmouse->dev->keybit);
                __set_bit(REL_WHEEL, psmouse->dev->relbit);

                if (!psmouse->vendor)
                        psmouse->vendor = "Generic";
                if (!psmouse->name)
                        psmouse->name = "Wheel Mouse";
                psmouse->pktsize = 4;
        }

        return 0;
}

/*
 * Try IntelliMouse/Explorer magic init.
 */
static int im_explorer_detect(struct psmouse *psmouse, bool set_properties)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        u8 param[2];

        intellimouse_detect(psmouse, 0);

        param[0] = 200;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
        param[0] = 200;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
        param[0] =  80;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
        ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);

        if (param[0] != 4)
                return -ENODEV;

        /* Magic to enable horizontal scrolling on IntelliMouse 4.0 */
        param[0] = 200;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
        param[0] =  80;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
        param[0] =  40;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);

        if (set_properties) {
                __set_bit(BTN_MIDDLE, psmouse->dev->keybit);
                __set_bit(REL_WHEEL, psmouse->dev->relbit);
                __set_bit(REL_HWHEEL, psmouse->dev->relbit);
                __set_bit(BTN_SIDE, psmouse->dev->keybit);
                __set_bit(BTN_EXTRA, psmouse->dev->keybit);

                if (!psmouse->vendor)
                        psmouse->vendor = "Generic";
                if (!psmouse->name)
                        psmouse->name = "Explorer Mouse";
                psmouse->pktsize = 4;
        }

        return 0;
}

/*
 * Kensington ThinkingMouse / ExpertMouse magic init.
 */
static int thinking_detect(struct psmouse *psmouse, bool set_properties)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        u8 param[2];
        static const u8 seq[] = { 20, 60, 40, 20, 20, 60, 40, 20, 20 };
        int i;

        param[0] = 10;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
        param[0] = 0;
        ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
        for (i = 0; i < ARRAY_SIZE(seq); i++) {
                param[0] = seq[i];
                ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
        }
        ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);

        if (param[0] != 2)
                return -ENODEV;

        if (set_properties) {
                __set_bit(BTN_MIDDLE, psmouse->dev->keybit);
                __set_bit(BTN_EXTRA, psmouse->dev->keybit);

                psmouse->vendor = "Kensington";
                psmouse->name = "ThinkingMouse";
        }

        return 0;
}

/*
 * Bare PS/2 protocol "detection". Always succeeds.
 */
static int ps2bare_detect(struct psmouse *psmouse, bool set_properties)
{
        if (set_properties) {
                if (!psmouse->vendor)
                        psmouse->vendor = "Generic";
                if (!psmouse->name)
                        psmouse->name = "Mouse";

                /*
                 * We have no way of figuring true number of buttons so let's
                 * assume that the device has 3.
                 */
                input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE);
        }

        return 0;
}

/*
 * Cortron PS/2 protocol detection. There's no special way to detect it, so it
 * must be forced by sysfs protocol writing.
 */
static int cortron_detect(struct psmouse *psmouse, bool set_properties)
{
        if (set_properties) {
                psmouse->vendor = "Cortron";
                psmouse->name = "PS/2 Trackball";

                __set_bit(BTN_MIDDLE, psmouse->dev->keybit);
                __set_bit(BTN_SIDE, psmouse->dev->keybit);
        }

        return 0;
}

static const struct psmouse_protocol psmouse_protocols[] = {
        {
                .type           = PSMOUSE_PS2,
                .name           = "PS/2",
                .alias          = "bare",
                .maxproto       = true,
                .ignore_parity  = true,
                .detect         = ps2bare_detect,
                .try_passthru   = true,
        },
#ifdef CONFIG_MOUSE_PS2_LOGIPS2PP
        {
                .type           = PSMOUSE_PS2PP,
                .name           = "PS2++",
                .alias          = "logitech",
                .detect         = ps2pp_detect,
        },
#endif
        {
                .type           = PSMOUSE_THINKPS,
                .name           = "ThinkPS/2",
                .alias          = "thinkps",
                .detect         = thinking_detect,
        },
#ifdef CONFIG_MOUSE_PS2_CYPRESS
        {
                .type           = PSMOUSE_CYPRESS,
                .name           = "CyPS/2",
                .alias          = "cypress",
                .detect         = cypress_detect,
                .init           = cypress_init,
        },
#endif
        {
                .type           = PSMOUSE_GENPS,
                .name           = "GenPS/2",
                .alias          = "genius",
                .detect         = genius_detect,
        },
        {
                .type           = PSMOUSE_IMPS,
                .name           = "ImPS/2",
                .alias          = "imps",
                .maxproto       = true,
                .ignore_parity  = true,
                .detect         = intellimouse_detect,
                .try_passthru   = true,
        },
        {
                .type           = PSMOUSE_IMEX,
                .name           = "ImExPS/2",
                .alias          = "exps",
                .maxproto       = true,
                .ignore_parity  = true,
                .detect         = im_explorer_detect,
                .try_passthru   = true,
        },
#ifdef CONFIG_MOUSE_PS2_SYNAPTICS
        {
                .type           = PSMOUSE_SYNAPTICS,
                .name           = "SynPS/2",
                .alias          = "synaptics",
                .detect         = synaptics_detect,
                .init           = synaptics_init_absolute,
        },
        {
                .type           = PSMOUSE_SYNAPTICS_RELATIVE,
                .name           = "SynRelPS/2",
                .alias          = "synaptics-relative",
                .detect         = synaptics_detect,
                .init           = synaptics_init_relative,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_SYNAPTICS_SMBUS
        {
                .type           = PSMOUSE_SYNAPTICS_SMBUS,
                .name           = "SynSMBus",
                .alias          = "synaptics-smbus",
                .detect         = synaptics_detect,
                .init           = synaptics_init_smbus,
                .smbus_companion = true,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_ALPS
        {
                .type           = PSMOUSE_ALPS,
                .name           = "AlpsPS/2",
                .alias          = "alps",
                .detect         = alps_detect,
                .init           = alps_init,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_LIFEBOOK
        {
                .type           = PSMOUSE_LIFEBOOK,
                .name           = "LBPS/2",
                .alias          = "lifebook",
                .detect         = lifebook_detect,
                .init           = lifebook_init,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_TRACKPOINT
        {
                .type           = PSMOUSE_TRACKPOINT,
                .name           = "TPPS/2",
                .alias          = "trackpoint",
                .detect         = trackpoint_detect,
                .try_passthru   = true,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_TOUCHKIT
        {
                .type           = PSMOUSE_TOUCHKIT_PS2,
                .name           = "touchkitPS/2",
                .alias          = "touchkit",
                .detect         = touchkit_ps2_detect,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_OLPC
        {
                .type           = PSMOUSE_HGPK,
                .name           = "OLPC HGPK",
                .alias          = "hgpk",
                .detect         = hgpk_detect,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_ELANTECH
        {
                .type           = PSMOUSE_ELANTECH,
                .name           = "ETPS/2",
                .alias          = "elantech",
                .detect         = elantech_detect,
                .init           = elantech_init_ps2,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_ELANTECH_SMBUS
        {
                .type           = PSMOUSE_ELANTECH_SMBUS,
                .name           = "ETSMBus",
                .alias          = "elantech-smbus",
                .detect         = elantech_detect,
                .init           = elantech_init_smbus,
                .smbus_companion = true,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_SENTELIC
        {
                .type           = PSMOUSE_FSP,
                .name           = "FSPPS/2",
                .alias          = "fsp",
                .detect         = fsp_detect,
                .init           = fsp_init,
        },
#endif
        {
                .type           = PSMOUSE_CORTRON,
                .name           = "CortronPS/2",
                .alias          = "cortps",
                .detect         = cortron_detect,
        },
#ifdef CONFIG_MOUSE_PS2_FOCALTECH
        {
                .type           = PSMOUSE_FOCALTECH,
                .name           = "FocalTechPS/2",
                .alias          = "focaltech",
                .detect         = focaltech_detect,
                .init           = focaltech_init,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_VMMOUSE
        {
                .type           = PSMOUSE_VMMOUSE,
                .name           = VMMOUSE_PSNAME,
                .alias          = "vmmouse",
                .detect         = vmmouse_detect,
                .init           = vmmouse_init,
        },
#endif
#ifdef CONFIG_MOUSE_PS2_BYD
        {
                .type           = PSMOUSE_BYD,
                .name           = "BYDPS/2",
                .alias          = "byd",
                .detect         = byd_detect,
                .init           = byd_init,
        },
#endif
        {
                .type           = PSMOUSE_AUTO,
                .name           = "auto",
                .alias          = "any",
                .maxproto       = true,
        },
};

static const struct psmouse_protocol *__psmouse_protocol_by_type(enum psmouse_type type)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(psmouse_protocols); i++)
                if (psmouse_protocols[i].type == type)
                        return &psmouse_protocols[i];

        return NULL;
}

static const struct psmouse_protocol *psmouse_protocol_by_type(enum psmouse_type type)
{
        const struct psmouse_protocol *proto;

        proto = __psmouse_protocol_by_type(type);
        if (proto)
                return proto;

        WARN_ON(1);
        return &psmouse_protocols[0];
}

static const struct psmouse_protocol *psmouse_protocol_by_name(const char *name, size_t len)
{
        const struct psmouse_protocol *p;
        int i;

        for (i = 0; i < ARRAY_SIZE(psmouse_protocols); i++) {
                p = &psmouse_protocols[i];

                if ((strlen(p->name) == len && !strncmp(p->name, name, len)) ||
                    (strlen(p->alias) == len && !strncmp(p->alias, name, len)))
                        return &psmouse_protocols[i];
        }

        return NULL;
}

/*
 * Apply default settings to the psmouse structure. Most of them will
 * be overridden by individual protocol initialization routines.
 */
static void psmouse_apply_defaults(struct psmouse *psmouse)
{
        struct input_dev *input_dev = psmouse->dev;

        bitmap_zero(input_dev->evbit, EV_CNT);
        bitmap_zero(input_dev->keybit, KEY_CNT);
        bitmap_zero(input_dev->relbit, REL_CNT);
        bitmap_zero(input_dev->absbit, ABS_CNT);
        bitmap_zero(input_dev->mscbit, MSC_CNT);

        input_set_capability(input_dev, EV_KEY, BTN_LEFT);
        input_set_capability(input_dev, EV_KEY, BTN_RIGHT);

        input_set_capability(input_dev, EV_REL, REL_X);
        input_set_capability(input_dev, EV_REL, REL_Y);

        __set_bit(INPUT_PROP_POINTER, input_dev->propbit);

        psmouse->protocol = &psmouse_protocols[0];

        psmouse->set_rate = psmouse_set_rate;
        psmouse->set_resolution = psmouse_set_resolution;
        psmouse->set_scale = psmouse_set_scale;
        psmouse->poll = psmouse_poll;
        psmouse->protocol_handler = psmouse_process_byte;
        psmouse->pktsize = 3;
        psmouse->reconnect = NULL;
        psmouse->fast_reconnect = NULL;
        psmouse->disconnect = NULL;
        psmouse->cleanup = NULL;
        psmouse->pt_activate = NULL;
        psmouse->pt_deactivate = NULL;
}

static bool psmouse_do_detect(int (*detect)(struct psmouse *, bool),
                              struct psmouse *psmouse, bool allow_passthrough,
                              bool set_properties)
{

        if (psmouse->ps2dev.serio->id.type == SERIO_PS_PSTHRU &&
            !allow_passthrough) {
                return false;
        }

        if (set_properties)
                psmouse_apply_defaults(psmouse);

        return detect(psmouse, set_properties) == 0;
}

static bool psmouse_try_protocol(struct psmouse *psmouse,
                                 enum psmouse_type type,
                                 unsigned int *max_proto,
                                 bool set_properties, bool init_allowed)
{
        const struct psmouse_protocol *proto;

        proto = __psmouse_protocol_by_type(type);
        if (!proto)
                return false;

        if (!psmouse_do_detect(proto->detect, psmouse, proto->try_passthru,
                               set_properties))
                return false;

        if (set_properties && proto->init && init_allowed) {
                if (proto->init(psmouse) != 0) {
                        /*
                         * We detected device, but init failed. Adjust
                         * max_proto so we only try standard protocols.
                         */
                        if (*max_proto > PSMOUSE_IMEX)
                                *max_proto = PSMOUSE_IMEX;

                        return false;
                }
        }

        return true;
}

/*
 * psmouse_extensions() probes for any extensions to the basic PS/2 protocol
 * the mouse may have.
 */
static int psmouse_extensions(struct psmouse *psmouse,
                              unsigned int max_proto, bool set_properties)
{
        bool synaptics_hardware = false;
        int ret;

        /*
         * Always check for focaltech, this is safe as it uses pnp-id
         * matching.
         */
        if (psmouse_do_detect(focaltech_detect,
                              psmouse, false, set_properties)) {
                if (max_proto > PSMOUSE_IMEX &&
                    IS_ENABLED(CONFIG_MOUSE_PS2_FOCALTECH) &&
                    (!set_properties || focaltech_init(psmouse) == 0)) {
                        return PSMOUSE_FOCALTECH;
                }
                /*
                 * Restrict psmouse_max_proto so that psmouse_initialize()
                 * does not try to reset rate and resolution, because even
                 * that upsets the device.
                 * This also causes us to basically fall through to basic
                 * protocol detection, where we fully reset the mouse,
                 * and set it up as bare PS/2 protocol device.
                 */
                psmouse_max_proto = max_proto = PSMOUSE_PS2;
        }

        /*
         * We always check for LifeBook because it does not disturb mouse
         * (it only checks DMI information).
         */
        if (psmouse_try_protocol(psmouse, PSMOUSE_LIFEBOOK, &max_proto,
                                 set_properties, max_proto > PSMOUSE_IMEX))
                return PSMOUSE_LIFEBOOK;

        if (psmouse_try_protocol(psmouse, PSMOUSE_VMMOUSE, &max_proto,
                                 set_properties, max_proto > PSMOUSE_IMEX))
                return PSMOUSE_VMMOUSE;

        /*
         * Try Kensington ThinkingMouse (we try first, because Synaptics
         * probe upsets the ThinkingMouse).
         */
        if (max_proto > PSMOUSE_IMEX &&
            psmouse_try_protocol(psmouse, PSMOUSE_THINKPS, &max_proto,
                                 set_properties, true)) {
                return PSMOUSE_THINKPS;
        }

        /*
         * Try Synaptics TouchPad. Note that probing is done even if
         * Synaptics protocol support is disabled in config - we need to
         * know if it is Synaptics so we can reset it properly after
         * probing for IntelliMouse.
         */
        if (max_proto > PSMOUSE_PS2 &&
            psmouse_do_detect(synaptics_detect,
                              psmouse, false, set_properties)) {
                synaptics_hardware = true;

                if (max_proto > PSMOUSE_IMEX) {
                        /*
                         * Try activating protocol, but check if support is
                         * enabled first, since we try detecting Synaptics
                         * even when protocol is disabled.
                         */
                        if (IS_ENABLED(CONFIG_MOUSE_PS2_SYNAPTICS) ||
                            IS_ENABLED(CONFIG_MOUSE_PS2_SYNAPTICS_SMBUS)) {
                                if (!set_properties)
                                        return PSMOUSE_SYNAPTICS;

                                ret = synaptics_init(psmouse);
                                if (ret >= 0)
                                        return ret;
                        }

                        /*
                         * Some Synaptics touchpads can emulate extended
                         * protocols (like IMPS/2).  Unfortunately
                         * Logitech/Genius probes confuse some firmware
                         * versions so we'll have to skip them.
                         */
                        max_proto = PSMOUSE_IMEX;
                }

                /*
                 * Make sure that touchpad is in relative mode, gestures
                 * (taps) are enabled.
                 */
                synaptics_reset(psmouse);
        }

        /*
         * Try Cypress Trackpad. We must try it before Finger Sensing Pad
         * because Finger Sensing Pad probe upsets some modules of Cypress
         * Trackpads.
         */
        if (max_proto > PSMOUSE_IMEX &&
            psmouse_try_protocol(psmouse, PSMOUSE_CYPRESS, &max_proto,
                                 set_properties, true)) {
                return PSMOUSE_CYPRESS;
        }

        /* Try ALPS TouchPad */
        if (max_proto > PSMOUSE_IMEX) {
                ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
                if (psmouse_try_protocol(psmouse, PSMOUSE_ALPS,
                                         &max_proto, set_properties, true))
                        return PSMOUSE_ALPS;
        }

        /* Try OLPC HGPK touchpad */
        if (max_proto > PSMOUSE_IMEX &&
            psmouse_try_protocol(psmouse, PSMOUSE_HGPK, &max_proto,
                                 set_properties, true)) {
                return PSMOUSE_HGPK;
        }

        /* Try Elantech touchpad */
        if (max_proto > PSMOUSE_IMEX &&
            psmouse_try_protocol(psmouse, PSMOUSE_ELANTECH,
                                 &max_proto, set_properties, false)) {
                if (!set_properties)
                        return PSMOUSE_ELANTECH;

                ret = elantech_init(psmouse);
                if (ret >= 0)
                        return ret;
        }

        if (max_proto > PSMOUSE_IMEX) {
                if (psmouse_try_protocol(psmouse, PSMOUSE_GENPS,
                                         &max_proto, set_properties, true))
                        return PSMOUSE_GENPS;

                if (psmouse_try_protocol(psmouse, PSMOUSE_PS2PP,
                                         &max_proto, set_properties, true))
                        return PSMOUSE_PS2PP;

                if (psmouse_try_protocol(psmouse, PSMOUSE_TRACKPOINT,
                                         &max_proto, set_properties, true))
                        return PSMOUSE_TRACKPOINT;

                if (psmouse_try_protocol(psmouse, PSMOUSE_TOUCHKIT_PS2,
                                         &max_proto, set_properties, true))
                        return PSMOUSE_TOUCHKIT_PS2;
        }

        /*
         * Try Finger Sensing Pad. We do it here because its probe upsets
         * Trackpoint devices (causing TP_READ_ID command to time out).
         */
        if (max_proto > PSMOUSE_IMEX &&
            psmouse_try_protocol(psmouse, PSMOUSE_FSP,
                                 &max_proto, set_properties, true)) {
                return PSMOUSE_FSP;
        }

        /*
         * Reset to defaults in case the device got confused by extended
         * protocol probes. Note that we follow up with full reset because
         * some mice put themselves to sleep when they see PSMOUSE_RESET_DIS.
         */
        ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
        psmouse_reset(psmouse);

        if (max_proto >= PSMOUSE_IMEX &&
            psmouse_try_protocol(psmouse, PSMOUSE_IMEX,
                                 &max_proto, set_properties, true)) {
                return PSMOUSE_IMEX;
        }

        if (max_proto >= PSMOUSE_IMPS &&
            psmouse_try_protocol(psmouse, PSMOUSE_IMPS,
                                 &max_proto, set_properties, true)) {
                return PSMOUSE_IMPS;
        }

        /*
         * Okay, all failed, we have a standard mouse here. The number of
         * the buttons is still a question, though. We assume 3.
         */
        psmouse_try_protocol(psmouse, PSMOUSE_PS2,
                             &max_proto, set_properties, true);

        if (synaptics_hardware) {
                /*
                 * We detected Synaptics hardware but it did not respond to
                 * IMPS/2 probes.  We need to reset the touchpad because if
                 * there is a track point on the pass through port it could
                 * get disabled while probing for protocol extensions.
                 */
                psmouse_reset(psmouse);
        }

        return PSMOUSE_PS2;
}

/*
 * psmouse_probe() probes for a PS/2 mouse.
 */
static int psmouse_probe(struct psmouse *psmouse)
{
        struct ps2dev *ps2dev = &psmouse->ps2dev;
        u8 param[2];
        int error;

        /*
         * First, we check if it's a mouse. It should send 0x00 or 0x03 in
         * case of an IntelliMouse in 4-byte mode or 0x04 for IM Explorer.
         * Sunrex K8561 IR Keyboard/Mouse reports 0xff on second and
         * subsequent ID queries, probably due to a firmware bug.
         */
        param[0] = 0xa5;
        error = ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);
        if (error)
                return error;

        if (param[0] != 0x00 && param[0] != 0x03 &&
            param[0] != 0x04 && param[0] != 0xff)
                return -ENODEV;

        /*
         * Then we reset and disable the mouse so that it doesn't generate
         * events.
         */
        error = ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
        if (error)
                psmouse_warn(psmouse, "Failed to reset mouse on %s: %d\n",
                             ps2dev->serio->phys, error);

        return 0;
}

/*
 * psmouse_initialize() initializes the mouse to a sane state.
 */
static void psmouse_initialize(struct psmouse *psmouse)
{
        /*
         * We set the mouse report rate, resolution and scaling.
         */
        if (psmouse_max_proto != PSMOUSE_PS2) {
                psmouse->set_rate(psmouse, psmouse->rate);
                psmouse->set_resolution(psmouse, psmouse->resolution);
                psmouse->set_scale(psmouse, PSMOUSE_SCALE11);
        }
}

/*
 * psmouse_activate() enables the mouse so that we get motion reports from it.
 */
int psmouse_activate(struct psmouse *psmouse)
{
        if (ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE)) {
                psmouse_warn(psmouse, "Failed to enable mouse on %s\n",
                             psmouse->ps2dev.serio->phys);
                return -1;
        }

        psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
        return 0;
}

/*
 * psmouse_deactivate() puts the mouse into poll mode so that we don't get
 * motion reports from it unless we explicitly request it.
 */
int psmouse_deactivate(struct psmouse *psmouse)
{
        int error;

        error = ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_DISABLE);
        if (error) {
                psmouse_warn(psmouse, "Failed to deactivate mouse on %s: %d\n",
                             psmouse->ps2dev.serio->phys, error);
                return error;
        }

        psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
        return 0;
}

/*
 * psmouse_resync() attempts to re-validate current protocol.
 */
static void psmouse_resync(struct work_struct *work)
{
        struct psmouse *parent = NULL, *psmouse =
                container_of(work, struct psmouse, resync_work.work);
        struct serio *serio = psmouse->ps2dev.serio;
        psmouse_ret_t rc = PSMOUSE_GOOD_DATA;
        bool failed = false, enabled = false;
        int i;

        mutex_lock(&psmouse_mutex);

        if (psmouse->state != PSMOUSE_RESYNCING)
                goto out;

        if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
                parent = serio_get_drvdata(serio->parent);
                psmouse_deactivate(parent);
        }

        /*
         * Some mice don't ACK commands sent while they are in the middle of
         * transmitting motion packet. To avoid delay we use ps2_sendbyte()
         * instead of ps2_command() which would wait for 200ms for an ACK
         * that may never come.
         * As an additional quirk ALPS touchpads may not only forget to ACK
         * disable command but will stop reporting taps, so if we see that
         * mouse at least once ACKs disable we will do full reconnect if ACK
         * is missing.
         */
        psmouse->num_resyncs++;

        if (ps2_sendbyte(&psmouse->ps2dev, PSMOUSE_CMD_DISABLE, 20)) {
                if (psmouse->num_resyncs < 3 || psmouse->acks_disable_command)
                        failed = true;
        } else
                psmouse->acks_disable_command = true;

        /*
         * Poll the mouse. If it was reset the packet will be shorter than
         * psmouse->pktsize and ps2_command will fail. We do not expect and
         * do not handle scenario when mouse "upgrades" its protocol while
         * disconnected since it would require additional delay. If we ever
         * see a mouse that does it we'll adjust the code.
         */
        if (!failed) {
                if (psmouse->poll(psmouse))
                        failed = true;
                else {
                        psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
                        for (i = 0; i < psmouse->pktsize; i++) {
                                psmouse->pktcnt++;
                                rc = psmouse->protocol_handler(psmouse);
                                if (rc != PSMOUSE_GOOD_DATA)
                                        break;
                        }
                        if (rc != PSMOUSE_FULL_PACKET)
                                failed = true;
                        psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
                }
        }

        /*
         * Now try to enable mouse. We try to do that even if poll failed
         * and also repeat our attempts 5 times, otherwise we may be left
         * out with disabled mouse.
         */
        for (i = 0; i < 5; i++) {
                if (!ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE)) {
                        enabled = true;
                        break;
                }
                msleep(200);
        }

        if (!enabled) {
                psmouse_warn(psmouse, "failed to re-enable mouse on %s\n",
                             psmouse->ps2dev.serio->phys);
                failed = true;
        }

        if (failed) {
                psmouse_set_state(psmouse, PSMOUSE_IGNORE);
                psmouse_info(psmouse,
                             "resync failed, issuing reconnect request\n");
                serio_reconnect(serio);
        } else
                psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);

        if (parent)
                psmouse_activate(parent);
 out:
        mutex_unlock(&psmouse_mutex);
}

/*
 * psmouse_cleanup() resets the mouse into power-on state.
 */
static void psmouse_cleanup(struct serio *serio)
{
        struct psmouse *psmouse = serio_get_drvdata(serio);
        struct psmouse *parent = NULL;

        mutex_lock(&psmouse_mutex);

        if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
                parent = serio_get_drvdata(serio->parent);
                psmouse_deactivate(parent);
        }

        psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);

        /*
         * Disable stream mode so cleanup routine can proceed undisturbed.
         */
        if (ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_DISABLE))
                psmouse_warn(psmouse, "Failed to disable mouse on %s\n",
                             psmouse->ps2dev.serio->phys);

        if (psmouse->cleanup)
                psmouse->cleanup(psmouse);

        /*
         * Reset the mouse to defaults (bare PS/2 protocol).
         */
        ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);

        /*
         * Some boxes, such as HP nx7400, get terribly confused if mouse
         * is not fully enabled before suspending/shutting down.
         */
        ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE);

        if (parent) {
                if (parent->pt_deactivate)
                        parent->pt_deactivate(parent);

                psmouse_activate(parent);
        }

        mutex_unlock(&psmouse_mutex);
}

/*
 * psmouse_disconnect() closes and frees.
 */
static void psmouse_disconnect(struct serio *serio)
{
        struct psmouse *psmouse = serio_get_drvdata(serio);
        struct psmouse *parent = NULL;

        sysfs_remove_group(&serio->dev.kobj, &psmouse_attribute_group);

        mutex_lock(&psmouse_mutex);

        psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);

        /* make sure we don't have a resync in progress */
        mutex_unlock(&psmouse_mutex);
        flush_workqueue(kpsmoused_wq);
        mutex_lock(&psmouse_mutex);

        if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
                parent = serio_get_drvdata(serio->parent);
                psmouse_deactivate(parent);
        }

        if (psmouse->disconnect)
                psmouse->disconnect(psmouse);

        if (parent && parent->pt_deactivate)
                parent->pt_deactivate(parent);

        psmouse_set_state(psmouse, PSMOUSE_IGNORE);

        serio_close(serio);
        serio_set_drvdata(serio, NULL);

        if (psmouse->dev)
                input_unregister_device(psmouse->dev);

        kfree(psmouse);

        if (parent)
                psmouse_activate(parent);

        mutex_unlock(&psmouse_mutex);
}

static int psmouse_switch_protocol(struct psmouse *psmouse,
                                   const struct psmouse_protocol *proto)
{
        const struct psmouse_protocol *selected_proto;
        struct input_dev *input_dev = psmouse->dev;
        enum psmouse_type type;

        input_dev->dev.parent = &psmouse->ps2dev.serio->dev;

        if (proto && (proto->detect || proto->init)) {
                psmouse_apply_defaults(psmouse);

                if (proto->detect && proto->detect(psmouse, true) < 0)
                        return -1;

                if (proto->init && proto->init(psmouse) < 0)
                        return -1;

                selected_proto = proto;
        } else {
                type = psmouse_extensions(psmouse, psmouse_max_proto, true);
                selected_proto = psmouse_protocol_by_type(type);
        }

        psmouse->protocol = selected_proto;

        /*
         * If mouse's packet size is 3 there is no point in polling the
         * device in hopes to detect protocol reset - we won't get less
         * than 3 bytes response anyhow.
         */
        if (psmouse->pktsize == 3)
                psmouse->resync_time = 0;

        /*
         * Some smart KVMs fake response to POLL command returning just
         * 3 bytes and messing up our resync logic, so if initial poll
         * fails we won't try polling the device anymore. Hopefully
         * such KVM will maintain initially selected protocol.
         */
        if (psmouse->resync_time && psmouse->poll(psmouse))
                psmouse->resync_time = 0;

        snprintf(psmouse->devname, sizeof(psmouse->devname), "%s %s %s",
                 selected_proto->name, psmouse->vendor, psmouse->name);

        input_dev->name = psmouse->devname;
        input_dev->phys = psmouse->phys;
        input_dev->id.bustype = BUS_I8042;
        input_dev->id.vendor = 0x0002;
        input_dev->id.product = psmouse->protocol->type;
        input_dev->id.version = psmouse->model;

        return 0;
}

/*
 * psmouse_connect() is a callback from the serio module when
 * an unhandled serio port is found.
 */
static int psmouse_connect(struct serio *serio, struct serio_driver *drv)
{
        struct psmouse *psmouse, *parent = NULL;
        struct input_dev *input_dev;
        int retval = 0, error = -ENOMEM;

        mutex_lock(&psmouse_mutex);

        /*
         * If this is a pass-through port deactivate parent so the device
         * connected to this port can be successfully identified
         */
        if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
                parent = serio_get_drvdata(serio->parent);
                psmouse_deactivate(parent);
        }

        psmouse = kzalloc(sizeof(struct psmouse), GFP_KERNEL);
        input_dev = input_allocate_device();
        if (!psmouse || !input_dev)
                goto err_free;

        ps2_init(&psmouse->ps2dev, serio);
        INIT_DELAYED_WORK(&psmouse->resync_work, psmouse_resync);
        psmouse->dev = input_dev;
        snprintf(psmouse->phys, sizeof(psmouse->phys), "%s/input0", serio->phys);

        psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);

        serio_set_drvdata(serio, psmouse);

        error = serio_open(serio, drv);
        if (error)
                goto err_clear_drvdata;

        /* give PT device some time to settle down before probing */
        if (serio->id.type == SERIO_PS_PSTHRU)
                usleep_range(10000, 15000);

        if (psmouse_probe(psmouse) < 0) {
                error = -ENODEV;
                goto err_close_serio;
        }

        psmouse->rate = psmouse_rate;
        psmouse->resolution = psmouse_resolution;
        psmouse->resetafter = psmouse_resetafter;
        psmouse->resync_time = parent ? 0 : psmouse_resync_time;
        psmouse->smartscroll = psmouse_smartscroll;

        psmouse_switch_protocol(psmouse, NULL);

        if (!psmouse->protocol->smbus_companion) {
                psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
                psmouse_initialize(psmouse);

                error = input_register_device(input_dev);
                if (error)
                        goto err_protocol_disconnect;
        } else {
                /* Smbus companion will be reporting events, not us. */
                input_free_device(input_dev);
                psmouse->dev = input_dev = NULL;
        }

        if (parent && parent->pt_activate)
                parent->pt_activate(parent);

        error = sysfs_create_group(&serio->dev.kobj, &psmouse_attribute_group);
        if (error)
                goto err_pt_deactivate;

        /*
         * PS/2 devices having SMBus companions should stay disabled
         * on PS/2 side, in order to have SMBus part operable.
         */
        if (!psmouse->protocol->smbus_companion)
                psmouse_activate(psmouse);

 out:
        /* If this is a pass-through port the parent needs to be re-activated */
        if (parent)
                psmouse_activate(parent);

        mutex_unlock(&psmouse_mutex);
        return retval;

 err_pt_deactivate:
        if (parent && parent->pt_deactivate)
                parent->pt_deactivate(parent);
        if (input_dev) {
                input_unregister_device(input_dev);
                input_dev = NULL; /* so we don't try to free it below */
        }
 err_protocol_disconnect:
        if (psmouse->disconnect)
                psmouse->disconnect(psmouse);
        psmouse_set_state(psmouse, PSMOUSE_IGNORE);
 err_close_serio:
        serio_close(serio);
 err_clear_drvdata:
        serio_set_drvdata(serio, NULL);
 err_free:
        input_free_device(input_dev);
        kfree(psmouse);

        retval = error;
        goto out;
}

static int __psmouse_reconnect(struct serio *serio, bool fast_reconnect)
{
        struct psmouse *psmouse = serio_get_drvdata(serio);
        struct psmouse *parent = NULL;
        int (*reconnect_handler)(struct psmouse *);
        enum psmouse_type type;
        int rc = -1;

        mutex_lock(&psmouse_mutex);

        if (fast_reconnect) {
                reconnect_handler = psmouse->fast_reconnect;
                if (!reconnect_handler) {
                        rc = -ENOENT;
                        goto out_unlock;
                }
        } else {
                reconnect_handler = psmouse->reconnect;
        }

        if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
                parent = serio_get_drvdata(serio->parent);
                psmouse_deactivate(parent);
        }

        psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);

        if (reconnect_handler) {
                if (reconnect_handler(psmouse))
                        goto out;
        } else {
                psmouse_reset(psmouse);

                if (psmouse_probe(psmouse) < 0)
                        goto out;

                type = psmouse_extensions(psmouse, psmouse_max_proto, false);
                if (psmouse->protocol->type != type)
                        goto out;
        }

        /*
         * OK, the device type (and capabilities) match the old one,
         * we can continue using it, complete initialization
         */
        if (!psmouse->protocol->smbus_companion) {
                psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
                psmouse_initialize(psmouse);
        }

        if (parent && parent->pt_activate)
                parent->pt_activate(parent);

        /*
         * PS/2 devices having SMBus companions should stay disabled
         * on PS/2 side, in order to have SMBus part operable.
         */
        if (!psmouse->protocol->smbus_companion)
                psmouse_activate(psmouse);

        rc = 0;

out:
        /* If this is a pass-through port the parent waits to be activated */
        if (parent)
                psmouse_activate(parent);

out_unlock:
        mutex_unlock(&psmouse_mutex);
        return rc;
}

static int psmouse_reconnect(struct serio *serio)
{
        return __psmouse_reconnect(serio, false);
}

static int psmouse_fast_reconnect(struct serio *serio)
{
        return __psmouse_reconnect(serio, true);
}

static struct serio_device_id psmouse_serio_ids[] = {
        {
                .type   = SERIO_8042,
                .proto  = SERIO_ANY,
                .id     = SERIO_ANY,
                .extra  = SERIO_ANY,
        },
        {
                .type   = SERIO_PS_PSTHRU,
                .proto  = SERIO_ANY,
                .id     = SERIO_ANY,
                .extra  = SERIO_ANY,
        },
        { 0 }
};

MODULE_DEVICE_TABLE(serio, psmouse_serio_ids);

static struct serio_driver psmouse_drv = {
        .driver         = {
                .name   = "psmouse",
        },
        .description    = DRIVER_DESC,
        .id_table       = psmouse_serio_ids,
        .interrupt      = psmouse_interrupt,
        .connect        = psmouse_connect,
        .reconnect      = psmouse_reconnect,
        .fast_reconnect = psmouse_fast_reconnect,
        .disconnect     = psmouse_disconnect,
        .cleanup        = psmouse_cleanup,
};

ssize_t psmouse_attr_show_helper(struct device *dev, struct device_attribute *devattr,
                                 char *buf)
{
        struct serio *serio = to_serio_port(dev);
        struct psmouse_attribute *attr = to_psmouse_attr(devattr);
        struct psmouse *psmouse = serio_get_drvdata(serio);

        if (psmouse->protocol->smbus_companion &&
                        devattr != &psmouse_attr_protocol.dattr)
                return -ENOENT;

        return attr->show(psmouse, attr->data, buf);
}

ssize_t psmouse_attr_set_helper(struct device *dev, struct device_attribute *devattr,
                                const char *buf, size_t count)
{
        struct serio *serio = to_serio_port(dev);
        struct psmouse_attribute *attr = to_psmouse_attr(devattr);
        struct psmouse *psmouse, *parent = NULL;
        int retval;

        retval = mutex_lock_interruptible(&psmouse_mutex);
        if (retval)
                goto out;

        psmouse = serio_get_drvdata(serio);

        if (psmouse->protocol->smbus_companion &&
                        devattr != &psmouse_attr_protocol.dattr) {
                retval = -ENOENT;
                goto out_unlock;
        }

        if (attr->protect) {
                if (psmouse->state == PSMOUSE_IGNORE) {
                        retval = -ENODEV;
                        goto out_unlock;
                }

                if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
                        parent = serio_get_drvdata(serio->parent);
                        psmouse_deactivate(parent);
                }

                if (!psmouse->protocol->smbus_companion)
                        psmouse_deactivate(psmouse);
        }

        retval = attr->set(psmouse, attr->data, buf, count);

        if (attr->protect) {
                if (retval != -ENODEV && !psmouse->protocol->smbus_companion)
                        psmouse_activate(psmouse);

                if (parent)
                        psmouse_activate(parent);
        }

 out_unlock:
        mutex_unlock(&psmouse_mutex);
 out:
        return retval;
}

static ssize_t psmouse_show_int_attr(struct psmouse *psmouse, void *offset, char *buf)
{
        unsigned int *field = (unsigned int *)((char *)psmouse + (size_t)offset);

        return sprintf(buf, "%u\n", *field);
}

static ssize_t psmouse_set_int_attr(struct psmouse *psmouse, void *offset, const char *buf, size_t count)
{
        unsigned int *field = (unsigned int *)((char *)psmouse + (size_t)offset);
        unsigned int value;
        int err;

        err = kstrtouint(buf, 10, &value);
        if (err)
                return err;

        *field = value;

        return count;
}

static ssize_t psmouse_attr_show_protocol(struct psmouse *psmouse, void *data, char *buf)
{
        return sprintf(buf, "%s\n", psmouse->protocol->name);
}

static ssize_t psmouse_attr_set_protocol(struct psmouse *psmouse, void *data, const char *buf, size_t count)
{
        struct serio *serio = psmouse->ps2dev.serio;
        struct psmouse *parent = NULL;
        struct input_dev *old_dev, *new_dev;
        const struct psmouse_protocol *proto, *old_proto;
        int error;
        int retry = 0;

        proto = psmouse_protocol_by_name(buf, count);
        if (!proto)
                return -EINVAL;

        if (psmouse->protocol == proto)
                return count;

        new_dev = input_allocate_device();
        if (!new_dev)
                return -ENOMEM;

        while (!list_empty(&serio->children)) {
                if (++retry > 3) {
                        psmouse_warn(psmouse,
                                     "failed to destroy children ports, protocol change aborted.\n");
                        input_free_device(new_dev);
                        return -EIO;
                }

                mutex_unlock(&psmouse_mutex);
                serio_unregister_child_port(serio);
                mutex_lock(&psmouse_mutex);

                if (serio->drv != &psmouse_drv) {
                        input_free_device(new_dev);
                        return -ENODEV;
                }

                if (psmouse->protocol == proto) {
                        input_free_device(new_dev);
                        return count; /* switched by other thread */
                }
        }

        if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
                parent = serio_get_drvdata(serio->parent);
                if (parent->pt_deactivate)
                        parent->pt_deactivate(parent);
        }

        old_dev = psmouse->dev;
        old_proto = psmouse->protocol;

        if (psmouse->disconnect)
                psmouse->disconnect(psmouse);

        psmouse_set_state(psmouse, PSMOUSE_IGNORE);

        psmouse->dev = new_dev;
        psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);

        if (psmouse_switch_protocol(psmouse, proto) < 0) {
                psmouse_reset(psmouse);
                /* default to PSMOUSE_PS2 */
                psmouse_switch_protocol(psmouse, &psmouse_protocols[0]);
        }

        psmouse_initialize(psmouse);
        psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);

        if (psmouse->protocol->smbus_companion) {
                input_free_device(psmouse->dev);
                psmouse->dev = NULL;
        } else {
                error = input_register_device(psmouse->dev);
                if (error) {
                        if (psmouse->disconnect)
                                psmouse->disconnect(psmouse);

                        psmouse_set_state(psmouse, PSMOUSE_IGNORE);
                        input_free_device(new_dev);
                        psmouse->dev = old_dev;
                        psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
                        psmouse_switch_protocol(psmouse, old_proto);
                        psmouse_initialize(psmouse);
                        psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);

                        return error;
                }
        }

        if (old_dev)
                input_unregister_device(old_dev);

        if (parent && parent->pt_activate)
                parent->pt_activate(parent);

        return count;
}

static ssize_t psmouse_attr_set_rate(struct psmouse *psmouse, void *data, const char *buf, size_t count)
{
        unsigned int value;
        int err;

        err = kstrtouint(buf, 10, &value);
        if (err)
                return err;

        psmouse->set_rate(psmouse, value);
        return count;
}

static ssize_t psmouse_attr_set_resolution(struct psmouse *psmouse, void *data, const char *buf, size_t count)
{
        unsigned int value;
        int err;

        err = kstrtouint(buf, 10, &value);
        if (err)
                return err;

        psmouse->set_resolution(psmouse, value);
        return count;
}


static int psmouse_set_maxproto(const char *val, const struct kernel_param *kp)
{
        const struct psmouse_protocol *proto;

        if (!val)
                return -EINVAL;

        proto = psmouse_protocol_by_name(val, strlen(val));

        if (!proto || !proto->maxproto)
                return -EINVAL;

        *((unsigned int *)kp->arg) = proto->type;

        return 0;
}

static int psmouse_get_maxproto(char *buffer, const struct kernel_param *kp)
{
        int type = *((unsigned int *)kp->arg);

        return sprintf(buffer, "%s", psmouse_protocol_by_type(type)->name);
}

static int __init psmouse_init(void)
{
        int err;

        lifebook_module_init();
        synaptics_module_init();
        hgpk_module_init();

        err = psmouse_smbus_module_init();
        if (err)
                return err;

        kpsmoused_wq = alloc_ordered_workqueue("kpsmoused", 0);
        if (!kpsmoused_wq) {
                pr_err("failed to create kpsmoused workqueue\n");
                err = -ENOMEM;
                goto err_smbus_exit;
        }

        err = serio_register_driver(&psmouse_drv);
        if (err)
                goto err_destroy_wq;

        return 0;

err_destroy_wq:
        destroy_workqueue(kpsmoused_wq);
err_smbus_exit:
        psmouse_smbus_module_exit();
        return err;
}

static void __exit psmouse_exit(void)
{
        serio_unregister_driver(&psmouse_drv);
        destroy_workqueue(kpsmoused_wq);
        psmouse_smbus_module_exit();
}

module_init(psmouse_init);
module_exit(psmouse_exit);