/*
 * Synaptics TouchPad PS/2 mouse driver
 *
 *   2003 Dmitry Torokhov <dtor@mail.ru>
 *     Added support for pass-through port. Special thanks to Peter Berg Larsen
 *     for explaining various Synaptics quirks.
 *
 *   2003 Peter Osterlund <petero2@telia.com>
 *     Ported to 2.5 input device infrastructure.
 *
 *   Copyright (C) 2001 Stefan Gmeiner <riddlebox@freesurf.ch>
 *     start merging tpconfig and gpm code to a xfree-input module
 *     adding some changes and extensions (ex. 3rd and 4th button)
 *
 *   Copyright (c) 1997 C. Scott Ananian <cananian@alumni.priceton.edu>
 *   Copyright (c) 1998-2000 Bruce Kalk <kall@compass.com>
 *     code for the special synaptics commands (from the tpconfig-source)
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * Trademarks are the property of their respective owners.
 */

#include <linux/module.h>
#include <linux/dmi.h>
#include <linux/input/mt.h>
#include <linux/serio.h>
#include <linux/libps2.h>
#include <linux/slab.h>
#include "psmouse.h"
#include "synaptics.h"

/*
 * The x/y limits are taken from the Synaptics TouchPad interfacing Guide,
 * section 2.3.2, which says that they should be valid regardless of the
 * actual size of the sensor.
 * Note that newer firmware allows querying device for maximum useable
 * coordinates.
 */
#define XMIN_NOMINAL 1472
#define XMAX_NOMINAL 5472
#define YMIN_NOMINAL 1408
#define YMAX_NOMINAL 4448

/*
 * Synaptics touchpads report the y coordinate from bottom to top, which is
 * opposite from what userspace expects.
 * This function is used to invert y before reporting.
 */
static int synaptics_invert_y(int y)
{
	return YMAX_NOMINAL + YMIN_NOMINAL - y;
}


/*****************************************************************************
 *	Stuff we need even when we do not want native Synaptics support
 ****************************************************************************/

/*
 * Set the synaptics touchpad mode byte by special commands
 */
static int synaptics_mode_cmd(struct psmouse *psmouse, unsigned char mode)
{
	unsigned char param[1];

	if (psmouse_sliced_command(psmouse, mode))
		return -1;
	param[0] = SYN_PS_SET_MODE2;
	if (ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_SETRATE))
		return -1;
	return 0;
}

int synaptics_detect(struct psmouse *psmouse, bool set_properties)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	unsigned char param[4];

	param[0] = 0;

	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
	ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO);

	if (param[1] != 0x47)
		return -ENODEV;

	if (set_properties) {
		psmouse->vendor = "Synaptics";
		psmouse->name = "TouchPad";
	}

	return 0;
}

void synaptics_reset(struct psmouse *psmouse)
{
	/* reset touchpad back to relative mode, gestures enabled */
	synaptics_mode_cmd(psmouse, 0);
}

#ifdef CONFIG_MOUSE_PS2_SYNAPTICS

/*****************************************************************************
 *	Synaptics communications functions
 ****************************************************************************/

/*
 * Send a command to the synpatics touchpad by special commands
 */
static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c, unsigned char *param)
{
	if (psmouse_sliced_command(psmouse, c))
		return -1;
	if (ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO))
		return -1;
	return 0;
}

/*
 * Read the model-id bytes from the touchpad
 * see also SYN_MODEL_* macros
 */
static int synaptics_model_id(struct psmouse *psmouse)
{
	struct synaptics_data *priv = psmouse->private;
	unsigned char mi[3];

	if (synaptics_send_cmd(psmouse, SYN_QUE_MODEL, mi))
		return -1;
	priv->model_id = (mi[0]<<16) | (mi[1]<<8) | mi[2];
	return 0;
}

/*
 * Read the capability-bits from the touchpad
 * see also the SYN_CAP_* macros
 */
static int synaptics_capability(struct psmouse *psmouse)
{
	struct synaptics_data *priv = psmouse->private;
	unsigned char cap[3];

	if (synaptics_send_cmd(psmouse, SYN_QUE_CAPABILITIES, cap))
		return -1;
	priv->capabilities = (cap[0] << 16) | (cap[1] << 8) | cap[2];
	priv->ext_cap = priv->ext_cap_0c = 0;

	/*
	 * Older firmwares had submodel ID fixed to 0x47
	 */
	if (SYN_ID_FULL(priv->identity) < 0x705 &&
	    SYN_CAP_SUBMODEL_ID(priv->capabilities) != 0x47) {
		return -1;
	}

	/*
	 * Unless capExtended is set the rest of the flags should be ignored
	 */
	if (!SYN_CAP_EXTENDED(priv->capabilities))
		priv->capabilities = 0;

	if (SYN_EXT_CAP_REQUESTS(priv->capabilities) >= 1) {
		if (synaptics_send_cmd(psmouse, SYN_QUE_EXT_CAPAB, cap)) {
			psmouse_warn(psmouse,
				     "device claims to have extended capabilities, but I'm not able to read them.\n");
		} else {
			priv->ext_cap = (cap[0] << 16) | (cap[1] << 8) | cap[2];

			/*
			 * if nExtBtn is greater than 8 it should be considered
			 * invalid and treated as 0
			 */
			if (SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap) > 8)
				priv->ext_cap &= 0xff0fff;
		}
	}

	if (SYN_EXT_CAP_REQUESTS(priv->capabilities) >= 4) {
		if (synaptics_send_cmd(psmouse, SYN_QUE_EXT_CAPAB_0C, cap)) {
			psmouse_warn(psmouse,
				     "device claims to have extended capability 0x0c, but I'm not able to read it.\n");
		} else {
			priv->ext_cap_0c = (cap[0] << 16) | (cap[1] << 8) | cap[2];
		}
	}

	return 0;
}

/*
 * Identify Touchpad
 * See also the SYN_ID_* macros
 */
static int synaptics_identify(struct psmouse *psmouse)
{
	struct synaptics_data *priv = psmouse->private;
	unsigned char id[3];

	if (synaptics_send_cmd(psmouse, SYN_QUE_IDENTIFY, id))
		return -1;
	priv->identity = (id[0]<<16) | (id[1]<<8) | id[2];
	if (SYN_ID_IS_SYNAPTICS(priv->identity))
		return 0;
	return -1;
}

/*
 * Read touchpad resolution and maximum reported coordinates
 * Resolution is left zero if touchpad does not support the query
 */
static int synaptics_resolution(struct psmouse *psmouse)
{
	struct synaptics_data *priv = psmouse->private;
	unsigned char resp[3];

	if (SYN_ID_MAJOR(priv->identity) < 4)
		return 0;

	if (synaptics_send_cmd(psmouse, SYN_QUE_RESOLUTION, resp) == 0) {
		if (resp[0] != 0 && (resp[1] & 0x80) && resp[2] != 0) {
			priv->x_res = resp[0]; /* x resolution in units/mm */
			priv->y_res = resp[2]; /* y resolution in units/mm */
		}
	}

	if (SYN_EXT_CAP_REQUESTS(priv->capabilities) >= 5 &&
	    SYN_CAP_MAX_DIMENSIONS(priv->ext_cap_0c)) {
		if (synaptics_send_cmd(psmouse, SYN_QUE_EXT_MAX_COORDS, resp)) {
			psmouse_warn(psmouse,
				     "device claims to have max coordinates query, but I'm not able to read it.\n");
		} else {
			priv->x_max = (resp[0] << 5) | ((resp[1] & 0x0f) << 1);
			priv->y_max = (resp[2] << 5) | ((resp[1] & 0xf0) >> 3);
		}
	}

	if (SYN_EXT_CAP_REQUESTS(priv->capabilities) >= 7 &&
	    SYN_CAP_MIN_DIMENSIONS(priv->ext_cap_0c)) {
		if (synaptics_send_cmd(psmouse, SYN_QUE_EXT_MIN_COORDS, resp)) {
			psmouse_warn(psmouse,
				     "device claims to have min coordinates query, but I'm not able to read it.\n");
		} else {
			priv->x_min = (resp[0] << 5) | ((resp[1] & 0x0f) << 1);
			priv->y_min = (resp[2] << 5) | ((resp[1] & 0xf0) >> 3);
		}
	}

	return 0;
}

static int synaptics_query_hardware(struct psmouse *psmouse)
{
	if (synaptics_identify(psmouse))
		return -1;
	if (synaptics_model_id(psmouse))
		return -1;
	if (synaptics_capability(psmouse))
		return -1;
	if (synaptics_resolution(psmouse))
		return -1;

	return 0;
}

static int synaptics_set_absolute_mode(struct psmouse *psmouse)
{
	struct synaptics_data *priv = psmouse->private;

	priv->mode = SYN_BIT_ABSOLUTE_MODE;
	if (SYN_ID_MAJOR(priv->identity) >= 4)
		priv->mode |= SYN_BIT_DISABLE_GESTURE;
	if (SYN_CAP_EXTENDED(priv->capabilities))
		priv->mode |= SYN_BIT_W_MODE;

	if (synaptics_mode_cmd(psmouse, priv->mode))
		return -1;

	return 0;
}

static void synaptics_set_rate(struct psmouse *psmouse, unsigned int rate)
{
	struct synaptics_data *priv = psmouse->private;

	if (rate >= 80) {
		priv->mode |= SYN_BIT_HIGH_RATE;
		psmouse->rate = 80;
	} else {
		priv->mode &= ~SYN_BIT_HIGH_RATE;
		psmouse->rate = 40;
	}

	synaptics_mode_cmd(psmouse, priv->mode);
}

static int synaptics_set_advanced_gesture_mode(struct psmouse *psmouse)
{
	static unsigned char param = 0xc8;
	struct synaptics_data *priv = psmouse->private;

	if (!(SYN_CAP_ADV_GESTURE(priv->ext_cap_0c) ||
			SYN_CAP_IMAGE_SENSOR(priv->ext_cap_0c)))
		return 0;

	if (psmouse_sliced_command(psmouse, SYN_QUE_MODEL))
		return -1;
	if (ps2_command(&psmouse->ps2dev, &param, PSMOUSE_CMD_SETRATE))
		return -1;

	/* Advanced gesture mode also sends multi finger data */
	priv->capabilities |= BIT(1);

	return 0;
}

/*****************************************************************************
 *	Synaptics pass-through PS/2 port support
 ****************************************************************************/
static int synaptics_pt_write(struct serio *serio, unsigned char c)
{
	struct psmouse *parent = serio_get_drvdata(serio->parent);
	char rate_param = SYN_PS_CLIENT_CMD; /* indicates that we want pass-through port */

	if (psmouse_sliced_command(parent, c))
		return -1;
	if (ps2_command(&parent->ps2dev, &rate_param, PSMOUSE_CMD_SETRATE))
		return -1;
	return 0;
}

static int synaptics_pt_start(struct serio *serio)
{
	struct psmouse *parent = serio_get_drvdata(serio->parent);
	struct synaptics_data *priv = parent->private;

	serio_pause_rx(parent->ps2dev.serio);
	priv->pt_port = serio;
	serio_continue_rx(parent->ps2dev.serio);

	return 0;
}

static void synaptics_pt_stop(struct serio *serio)
{
	struct psmouse *parent = serio_get_drvdata(serio->parent);
	struct synaptics_data *priv = parent->private;

	serio_pause_rx(parent->ps2dev.serio);
	priv->pt_port = NULL;
	serio_continue_rx(parent->ps2dev.serio);
}

static int synaptics_is_pt_packet(unsigned char *buf)
{
	return (buf[0] & 0xFC) == 0x84 && (buf[3] & 0xCC) == 0xC4;
}

static void synaptics_pass_pt_packet(struct serio *ptport, unsigned char *packet)
{
	struct psmouse *child = serio_get_drvdata(ptport);

	if (child && child->state == PSMOUSE_ACTIVATED) {
		serio_interrupt(ptport, packet[1], 0);
		serio_interrupt(ptport, packet[4], 0);
		serio_interrupt(ptport, packet[5], 0);
		if (child->pktsize == 4)
			serio_interrupt(ptport, packet[2], 0);
	} else
		serio_interrupt(ptport, packet[1], 0);
}

static void synaptics_pt_activate(struct psmouse *psmouse)
{
	struct synaptics_data *priv = psmouse->private;
	struct psmouse *child = serio_get_drvdata(priv->pt_port);

	/* adjust the touchpad to child's choice of protocol */
	if (child) {
		if (child->pktsize == 4)
			priv->mode |= SYN_BIT_FOUR_BYTE_CLIENT;
		else
			priv->mode &= ~SYN_BIT_FOUR_BYTE_CLIENT;

		if (synaptics_mode_cmd(psmouse, priv->mode))
			psmouse_warn(psmouse,
				     "failed to switch guest protocol\n");
	}
}

static void synaptics_pt_create(struct psmouse *psmouse)
{
	struct serio *serio;

	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
	if (!serio) {
		psmouse_err(psmouse,
			    "not enough memory for pass-through port\n");
		return;
	}

	serio->id.type = SERIO_PS_PSTHRU;
	strlcpy(serio->name, "Synaptics pass-through", sizeof(serio->name));
	strlcpy(serio->phys, "synaptics-pt/serio0", sizeof(serio->name));
	serio->write = synaptics_pt_write;
	serio->start = synaptics_pt_start;
	serio->stop = synaptics_pt_stop;
	serio->parent = psmouse->ps2dev.serio;

	psmouse->pt_activate = synaptics_pt_activate;

	psmouse_info(psmouse, "serio: %s port at %s\n",
		     serio->name, psmouse->phys);
	serio_register_port(serio);
}

/*****************************************************************************
 *	Functions to interpret the absolute mode packets
 ****************************************************************************/

static void synaptics_mt_state_set(struct synaptics_mt_state *state, int count,
				   int sgm, int agm)
{
	state->count = count;
	state->sgm = sgm;
	state->agm = agm;
}

static void synaptics_parse_agm(const unsigned char buf[],
				struct synaptics_data *priv,
				struct synaptics_hw_state *hw)
{
	struct synaptics_hw_state *agm = &priv->agm;
	int agm_packet_type;

	agm_packet_type = (buf[5] & 0x30) >> 4;
	switch (agm_packet_type) {
	case 1:
		/* Gesture packet: (x, y, z) half resolution */
		agm->w = hw->w;
		agm->x = (((buf[4] & 0x0f) << 8) | buf[1]) << 1;
		agm->y = (((buf[4] & 0xf0) << 4) | buf[2]) << 1;
		agm->z = ((buf[3] & 0x30) | (buf[5] & 0x0f)) << 1;
		break;

	case 2:
		/* AGM-CONTACT packet: (count, sgm, agm) */
		synaptics_mt_state_set(&agm->mt_state, buf[1], buf[2], buf[4]);
		break;

	default:
		break;
	}

	/* Record that at least one AGM has been received since last SGM */
	priv->agm_pending = true;
}

static int synaptics_parse_hw_state(const unsigned char buf[],
				    struct synaptics_data *priv,
				    struct synaptics_hw_state *hw)
{
	memset(hw, 0, sizeof(struct synaptics_hw_state));

	if (SYN_MODEL_NEWABS(priv->model_id)) {
		hw->w = (((buf[0] & 0x30) >> 2) |
			 ((buf[0] & 0x04) >> 1) |
			 ((buf[3] & 0x04) >> 2));

		hw->left  = (buf[0] & 0x01) ? 1 : 0;
		hw->right = (buf[0] & 0x02) ? 1 : 0;

		if (SYN_CAP_CLICKPAD(priv->ext_cap_0c)) {
			/*
			 * Clickpad's button is transmitted as middle button,
			 * however, since it is primary button, we will report
			 * it as BTN_LEFT.
			 */
			hw->left = ((buf[0] ^ buf[3]) & 0x01) ? 1 : 0;

		} else if (SYN_CAP_MIDDLE_BUTTON(priv->capabilities)) {
			hw->middle = ((buf[0] ^ buf[3]) & 0x01) ? 1 : 0;
			if (hw->w == 2)
				hw->scroll = (signed char)(buf[1]);
		}

		if (SYN_CAP_FOUR_BUTTON(priv->capabilities)) {
			hw->up   = ((buf[0] ^ buf[3]) & 0x01) ? 1 : 0;
			hw->down = ((buf[0] ^ buf[3]) & 0x02) ? 1 : 0;
		}

		if ((SYN_CAP_ADV_GESTURE(priv->ext_cap_0c) ||
			SYN_CAP_IMAGE_SENSOR(priv->ext_cap_0c)) &&
		    hw->w == 2) {
			synaptics_parse_agm(buf, priv, hw);
			return 1;
		}

		hw->x = (((buf[3] & 0x10) << 8) |
			 ((buf[1] & 0x0f) << 8) |
			 buf[4]);
		hw->y = (((buf[3] & 0x20) << 7) |
			 ((buf[1] & 0xf0) << 4) |
			 buf[5]);
		hw->z = buf[2];

		if (SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap) &&
		    ((buf[0] ^ buf[3]) & 0x02)) {
			switch (SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap) & ~0x01) {
			default:
				/*
				 * if nExtBtn is greater than 8 it should be
				 * considered invalid and treated as 0
				 */
				break;
			case 8:
				hw->ext_buttons |= ((buf[5] & 0x08)) ? 0x80 : 0;
				hw->ext_buttons |= ((buf[4] & 0x08)) ? 0x40 : 0;
			case 6:
				hw->ext_buttons |= ((buf[5] & 0x04)) ? 0x20 : 0;
				hw->ext_buttons |= ((buf[4] & 0x04)) ? 0x10 : 0;
			case 4:
				hw->ext_buttons |= ((buf[5] & 0x02)) ? 0x08 : 0;
				hw->ext_buttons |= ((buf[4] & 0x02)) ? 0x04 : 0;
			case 2:
				hw->ext_buttons |= ((buf[5] & 0x01)) ? 0x02 : 0;
				hw->ext_buttons |= ((buf[4] & 0x01)) ? 0x01 : 0;
			}
		}
	} else {
		hw->x = (((buf[1] & 0x1f) << 8) | buf[2]);
		hw->y = (((buf[4] & 0x1f) << 8) | buf[5]);

		hw->z = (((buf[0] & 0x30) << 2) | (buf[3] & 0x3F));
		hw->w = (((buf[1] & 0x80) >> 4) | ((buf[0] & 0x04) >> 1));

		hw->left  = (buf[0] & 0x01) ? 1 : 0;
		hw->right = (buf[0] & 0x02) ? 1 : 0;
	}

	return 0;
}

static void synaptics_report_semi_mt_slot(struct input_dev *dev, int slot,
					  bool active, int x, int y)
{
	input_mt_slot(dev, slot);
	input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
	if (active) {
		input_report_abs(dev, ABS_MT_POSITION_X, x);
		input_report_abs(dev, ABS_MT_POSITION_Y, synaptics_invert_y(y));
	}
}

static void synaptics_report_semi_mt_data(struct input_dev *dev,
					  const struct synaptics_hw_state *a,
					  const struct synaptics_hw_state *b,
					  int num_fingers)
{
	if (num_fingers >= 2) {
		synaptics_report_semi_mt_slot(dev, 0, true, min(a->x, b->x),
					      min(a->y, b->y));
		synaptics_report_semi_mt_slot(dev, 1, true, max(a->x, b->x),
					      max(a->y, b->y));
	} else if (num_fingers == 1) {
		synaptics_report_semi_mt_slot(dev, 0, true, a->x, a->y);
		synaptics_report_semi_mt_slot(dev, 1, false, 0, 0);
	} else {
		synaptics_report_semi_mt_slot(dev, 0, false, 0, 0);
		synaptics_report_semi_mt_slot(dev, 1, false, 0, 0);
	}
}

static void synaptics_report_buttons(struct psmouse *psmouse,
				     const struct synaptics_hw_state *hw)
{
	struct input_dev *dev = psmouse->dev;
	struct synaptics_data *priv = psmouse->private;
	int i;

	input_report_key(dev, BTN_LEFT, hw->left);
	input_report_key(dev, BTN_RIGHT, hw->right);

	if (SYN_CAP_MIDDLE_BUTTON(priv->capabilities))
		input_report_key(dev, BTN_MIDDLE, hw->middle);

	if (SYN_CAP_FOUR_BUTTON(priv->capabilities)) {
		input_report_key(dev, BTN_FORWARD, hw->up);
		input_report_key(dev, BTN_BACK, hw->down);
	}

	for (i = 0; i < SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap); i++)
		input_report_key(dev, BTN_0 + i, hw->ext_buttons & (1 << i));
}

static void synaptics_report_slot(struct input_dev *dev, int slot,
				  const struct synaptics_hw_state *hw)
{
	input_mt_slot(dev, slot);
	input_mt_report_slot_state(dev, MT_TOOL_FINGER, (hw != NULL));
	if (!hw)
		return;

	input_report_abs(dev, ABS_MT_POSITION_X, hw->x);
	input_report_abs(dev, ABS_MT_POSITION_Y, synaptics_invert_y(hw->y));
	input_report_abs(dev, ABS_MT_PRESSURE, hw->z);
}

static void synaptics_report_mt_data(struct psmouse *psmouse,
				     struct synaptics_mt_state *mt_state,
				     const struct synaptics_hw_state *sgm)
{
	struct input_dev *dev = psmouse->dev;
	struct synaptics_data *priv = psmouse->private;
	struct synaptics_hw_state *agm = &priv->agm;
	struct synaptics_mt_state *old = &priv->mt_state;

	switch (mt_state->count) {
	case 0:
		synaptics_report_slot(dev, 0, NULL);
		synaptics_report_slot(dev, 1, NULL);
		break;
	case 1:
		if (mt_state->sgm == -1) {
			synaptics_report_slot(dev, 0, NULL);
			synaptics_report_slot(dev, 1, NULL);
		} else if (mt_state->sgm == 0) {
			synaptics_report_slot(dev, 0, sgm);
			synaptics_report_slot(dev, 1, NULL);
		} else {
			synaptics_report_slot(dev, 0, NULL);
			synaptics_report_slot(dev, 1, sgm);
		}
		break;
	default:
		/*
		 * If the finger slot contained in SGM is valid, and either
		 * hasn't changed, or is new, then report SGM in MTB slot 0.
		 * Otherwise, empty MTB slot 0.
		 */
		if (mt_state->sgm != -1 &&
		    (mt_state->sgm == old->sgm || old->sgm == -1))
			synaptics_report_slot(dev, 0, sgm);
		else
			synaptics_report_slot(dev, 0, NULL);

		/*
		 * If the finger slot contained in AGM is valid, and either
		 * hasn't changed, or is new, then report AGM in MTB slot 1.
		 * Otherwise, empty MTB slot 1.
		 */
		if (mt_state->agm != -1 &&
		    (mt_state->agm == old->agm || old->agm == -1))
			synaptics_report_slot(dev, 1, agm);
		else
			synaptics_report_slot(dev, 1, NULL);
		break;
	}

	/* Don't use active slot count to generate BTN_TOOL events. */
	input_mt_report_pointer_emulation(dev, false);

	/* Send the number of fingers reported by touchpad itself. */
	input_mt_report_finger_count(dev, mt_state->count);

	synaptics_report_buttons(psmouse, sgm);

	input_sync(dev);
}

/* Handle case where mt_state->count = 0 */
static void synaptics_image_sensor_0f(struct synaptics_data *priv,
				      struct synaptics_mt_state *mt_state)
{
	synaptics_mt_state_set(mt_state, 0, -1, -1);
	priv->mt_state_lost = false;
}

/* Handle case where mt_state->count = 1 */
static void synaptics_image_sensor_1f(struct synaptics_data *priv,
				      struct synaptics_mt_state *mt_state)
{
	struct synaptics_hw_state *agm = &priv->agm;
	struct synaptics_mt_state *old = &priv->mt_state;

	/*
	 * If the last AGM was (0,0,0), and there is only one finger left,
	 * then we absolutely know that SGM contains slot 0, and all other
	 * fingers have been removed.
	 */
	if (priv->agm_pending && agm->z == 0) {
		synaptics_mt_state_set(mt_state, 1, 0, -1);
		priv->mt_state_lost = false;
		return;
	}

	switch (old->count) {
	case 0:
		synaptics_mt_state_set(mt_state, 1, 0, -1);
		break;
	case 1:
		/*
		 * If mt_state_lost, then the previous transition was 3->1,
		 * and SGM now contains either slot 0 or 1, but we don't know
		 * which.  So, we just assume that the SGM now contains slot 1.
		 *
		 * If pending AGM and either:
		 *   (a) the previous SGM slot contains slot 0, or
		 *   (b) there was no SGM slot
		 * then, the SGM now contains slot 1
		 *
		 * Case (a) happens with very rapid "drum roll" gestures, where
		 * slot 0 finger is lifted and a new slot 1 finger touches
		 * within one reporting interval.
		 *
		 * Case (b) happens if initially two or more fingers tap
		 * briefly, and all but one lift before the end of the first
		 * reporting interval.
		 *
		 * (In both these cases, slot 0 will becomes empty, so SGM
		 * contains slot 1 with the new finger)
		 *
		 * Else, if there was no previous SGM, it now contains slot 0.
		 *
		 * Otherwise, SGM still contains the same slot.
		 */
		if (priv->mt_state_lost ||
		    (priv->agm_pending && old->sgm <= 0))
			synaptics_mt_state_set(mt_state, 1, 1, -1);
		else if (old->sgm == -1)
			synaptics_mt_state_set(mt_state, 1, 0, -1);
		break;
	case 2:
		/*
		 * If mt_state_lost, we don't know which finger SGM contains.
		 *
		 * So, report 1 finger, but with both slots empty.
		 * We will use slot 1 on subsequent 1->1
		 */
		if (priv->mt_state_lost) {
			synaptics_mt_state_set(mt_state, 1, -1, -1);
			break;
		}
		/*
		 * Since the last AGM was NOT (0,0,0), it was the finger in
		 * slot 0 that has been removed.
		 * So, SGM now contains previous AGM's slot, and AGM is now
		 * empty.
		 */
		synaptics_mt_state_set(mt_state, 1, old->agm, -1);
		break;
	case 3:
		/*
		 * Since last AGM was not (0,0,0), we don't know which finger
		 * is left.
		 *
		 * So, report 1 finger, but with both slots empty.
		 * We will use slot 1 on subsequent 1->1
		 */
		synaptics_mt_state_set(mt_state, 1, -1, -1);
		priv->mt_state_lost = true;
		break;
	case 4:
	case 5:
		/* mt_state was updated by AGM-CONTACT packet */
		break;
	}
}

/* Handle case where mt_state->count = 2 */
static void synaptics_image_sensor_2f(struct synaptics_data *priv,
				      struct synaptics_mt_state *mt_state)
{
	struct synaptics_mt_state *old = &priv->mt_state;

	switch (old->count) {
	case 0:
		synaptics_mt_state_set(mt_state, 2, 0, 1);
		break;
	case 1:
		/*
		 * If previous SGM contained slot 1 or higher, SGM now contains
		 * slot 0 (the newly touching finger) and AGM contains SGM's
		 * previous slot.
		 *
		 * Otherwise, SGM still contains slot 0 and AGM now contains
		 * slot 1.
		 */
		if (old->sgm >= 1)
			synaptics_mt_state_set(mt_state, 2, 0, old->sgm);
		else
			synaptics_mt_state_set(mt_state, 2, 0, 1);
		break;
	case 2:
		/*
		 * If mt_state_lost, SGM now contains either finger 1 or 2, but
		 * we don't know which.
		 * So, we just assume that the SGM contains slot 0 and AGM 1.
		 */
		if (priv->mt_state_lost)
			synaptics_mt_state_set(mt_state, 2, 0, 1);
		/*
		 * Otherwise, use the same mt_state, since it either hasn't
		 * changed, or was updated by a recently received AGM-CONTACT
		 * packet.
		 */
		break;
	case 3:
		/*
		 * 3->2 transitions have two unsolvable problems:
		 *  1) no indication is given which finger was removed
		 *  2) no way to tell if agm packet was for finger 3
		 *     before 3->2, or finger 2 after 3->2.
		 *
		 * So, report 2 fingers, but empty all slots.
		 * We will guess slots [0,1] on subsequent 2->2.
		 */
		synaptics_mt_state_set(mt_state, 2, -1, -1);
		priv->mt_state_lost = true;
		break;
	case 4:
	case 5:
		/* mt_state was updated by AGM-CONTACT packet */
		break;
	}
}

/* Handle case where mt_state->count = 3 */
static void synaptics_image_sensor_3f(struct synaptics_data *priv,
				      struct synaptics_mt_state *mt_state)
{
	struct synaptics_mt_state *old = &priv->mt_state;

	switch (old->count) {
	case 0:
		synaptics_mt_state_set(mt_state, 3, 0, 2);
		break;
	case 1:
		/*
		 * If previous SGM contained slot 2 or higher, SGM now contains
		 * slot 0 (one of the newly touching fingers) and AGM contains
		 * SGM's previous slot.
		 *
		 * Otherwise, SGM now contains slot 0 and AGM contains slot 2.
		 */
		if (old->sgm >= 2)
			synaptics_mt_state_set(mt_state, 3, 0, old->sgm);
		else
			synaptics_mt_state_set(mt_state, 3, 0, 2);
		break;
	case 2:
		/*
		 * If the AGM previously contained slot 3 or higher, then the
		 * newly touching finger is in the lowest available slot.
		 *
		 * If SGM was previously 1 or higher, then the new SGM is
		 * now slot 0 (with a new finger), otherwise, the new finger
		 * is now in a hidden slot between 0 and AGM's slot.
		 *
		 * In all such cases, the SGM now contains slot 0, and the AGM
		 * continues to contain the same slot as before.
		 */
		if (old->agm >= 3) {
			synaptics_mt_state_set(mt_state, 3, 0, old->agm);
			break;
		}

		/*
		 * After some 3->1 and all 3->2 transitions, we lose track
		 * of which slot is reported by SGM and AGM.
		 *
		 * For 2->3 in this state, report 3 fingers, but empty all
		 * slots, and we will guess (0,2) on a subsequent 0->3.
		 *
		 * To userspace, the resulting transition will look like:
		 *    2:[0,1] -> 3:[-1,-1] -> 3:[0,2]
		 */
		if (priv->mt_state_lost) {
			synaptics_mt_state_set(mt_state, 3, -1, -1);
			break;
		}

		/*
		 * If the (SGM,AGM) really previously contained slots (0, 1),
		 * then we cannot know what slot was just reported by the AGM,
		 * because the 2->3 transition can occur either before or after
		 * the AGM packet. Thus, this most recent AGM could contain
		 * either the same old slot 1 or the new slot 2.
		 * Subsequent AGMs will be reporting slot 2.
		 *
		 * To userspace, the resulting transition will look like:
		 *    2:[0,1] -> 3:[0,-1] -> 3:[0,2]
		 */
		synaptics_mt_state_set(mt_state, 3, 0, -1);
		break;
	case 3:
		/*
		 * If, for whatever reason, the previous agm was invalid,
		 * Assume SGM now contains slot 0, AGM now contains slot 2.
		 */
		if (old->agm <= 2)
			synaptics_mt_state_set(mt_state, 3, 0, 2);
		/*
		 * mt_state either hasn't changed, or was updated by a recently
		 * received AGM-CONTACT packet.
		 */
		break;

	case 4:
	case 5:
		/* mt_state was updated by AGM-CONTACT packet */
		break;
	}
}

/* Handle case where mt_state->count = 4, or = 5 */
static void synaptics_image_sensor_45f(struct synaptics_data *priv,
				       struct synaptics_mt_state *mt_state)
{
	/* mt_state was updated correctly by AGM-CONTACT packet */
	priv->mt_state_lost = false;
}

static void synaptics_image_sensor_process(struct psmouse *psmouse,
					   struct synaptics_hw_state *sgm)
{
	struct synaptics_data *priv = psmouse->private;
	struct synaptics_hw_state *agm = &priv->agm;
	struct synaptics_mt_state mt_state;

	/* Initialize using current mt_state (as updated by last agm) */
	mt_state = agm->mt_state;

	/*
	 * Update mt_state using the new finger count and current mt_state.
	 */
	if (sgm->z == 0)
		synaptics_image_sensor_0f(priv, &mt_state);
	else if (sgm->w >= 4)
		synaptics_image_sensor_1f(priv, &mt_state);
	else if (sgm->w == 0)
		synaptics_image_sensor_2f(priv, &mt_state);
	else if (sgm->w == 1 && mt_state.count <= 3)
		synaptics_image_sensor_3f(priv, &mt_state);
	else
		synaptics_image_sensor_45f(priv, &mt_state);

	/* Send resulting input events to user space */
	synaptics_report_mt_data(psmouse, &mt_state, sgm);

	/* Store updated mt_state */
	priv->mt_state = agm->mt_state = mt_state;
	priv->agm_pending = false;
}

/*
 *  called for each full received packet from the touchpad
 */
static void synaptics_process_packet(struct psmouse *psmouse)
{
	struct input_dev *dev = psmouse->dev;
	struct synaptics_data *priv = psmouse->private;
	struct synaptics_hw_state hw;
	int num_fingers;
	int finger_width;

	if (synaptics_parse_hw_state(psmouse->packet, priv, &hw))
		return;

	if (SYN_CAP_IMAGE_SENSOR(priv->ext_cap_0c)) {
		synaptics_image_sensor_process(psmouse, &hw);
		return;
	}

	if (hw.scroll) {
		priv->scroll += hw.scroll;

		while (priv->scroll >= 4) {
			input_report_key(dev, BTN_BACK, !hw.down);
			input_sync(dev);
			input_report_key(dev, BTN_BACK, hw.down);
			input_sync(dev);
			priv->scroll -= 4;
		}
		while (priv->scroll <= -4) {
			input_report_key(dev, BTN_FORWARD, !hw.up);
			input_sync(dev);
			input_report_key(dev, BTN_FORWARD, hw.up);
			input_sync(dev);
			priv->scroll += 4;
		}
		return;
	}

	if (hw.z > 0 && hw.x > 1) {
		num_fingers = 1;
		finger_width = 5;
		if (SYN_CAP_EXTENDED(priv->capabilities)) {
			switch (hw.w) {
			case 0 ... 1:
				if (SYN_CAP_MULTIFINGER(priv->capabilities))
					num_fingers = hw.w + 2;
				break;
			case 2:
				if (SYN_MODEL_PEN(priv->model_id))
					;   /* Nothing, treat a pen as a single finger */
				break;
			case 4 ... 15:
				if (SYN_CAP_PALMDETECT(priv->capabilities))
					finger_width = hw.w;
				break;
			}
		}
	} else {
		num_fingers = 0;
		finger_width = 0;
	}

	if (SYN_CAP_ADV_GESTURE(priv->ext_cap_0c))
		synaptics_report_semi_mt_data(dev, &hw, &priv->agm,
					      num_fingers);

	/* Post events
	 * BTN_TOUCH has to be first as mousedev relies on it when doing
	 * absolute -> relative conversion
	 */
	if (hw.z > 30) input_report_key(dev, BTN_TOUCH, 1);
	if (hw.z < 25) input_report_key(dev, BTN_TOUCH, 0);

	if (num_fingers > 0) {
		input_report_abs(dev, ABS_X, hw.x);
		input_report_abs(dev, ABS_Y, synaptics_invert_y(hw.y));
	}
	input_report_abs(dev, ABS_PRESSURE, hw.z);

	if (SYN_CAP_PALMDETECT(priv->capabilities))
		input_report_abs(dev, ABS_TOOL_WIDTH, finger_width);

	input_report_key(dev, BTN_TOOL_FINGER, num_fingers == 1);
	if (SYN_CAP_MULTIFINGER(priv->capabilities)) {
		input_report_key(dev, BTN_TOOL_DOUBLETAP, num_fingers == 2);
		input_report_key(dev, BTN_TOOL_TRIPLETAP, num_fingers == 3);
	}

	synaptics_report_buttons(psmouse, &hw);

	input_sync(dev);
}

static int synaptics_validate_byte(struct psmouse *psmouse,
				   int idx, unsigned char pkt_type)
{
	static const unsigned char newabs_mask[]	= { 0xC8, 0x00, 0x00, 0xC8, 0x00 };
	static const unsigned char newabs_rel_mask[]	= { 0xC0, 0x00, 0x00, 0xC0, 0x00 };
	static const unsigned char newabs_rslt[]	= { 0x80, 0x00, 0x00, 0xC0, 0x00 };
	static const unsigned char oldabs_mask[]	= { 0xC0, 0x60, 0x00, 0xC0, 0x60 };
	static const unsigned char oldabs_rslt[]	= { 0xC0, 0x00, 0x00, 0x80, 0x00 };
	const char *packet = psmouse->packet;

	if (idx < 0 || idx > 4)
		return 0;

	switch (pkt_type) {

	case SYN_NEWABS:
	case SYN_NEWABS_RELAXED:
		return (packet[idx] & newabs_rel_mask[idx]) == newabs_rslt[idx];

	case SYN_NEWABS_STRICT:
		return (packet[idx] & newabs_mask[idx]) == newabs_rslt[idx];

	case SYN_OLDABS:
		return (packet[idx] & oldabs_mask[idx]) == oldabs_rslt[idx];

	default:
		psmouse_err(psmouse, "unknown packet type %d\n", pkt_type);
		return 0;
	}
}

static unsigned char synaptics_detect_pkt_type(struct psmouse *psmouse)
{
	int i;

	for (i = 0; i < 5; i++)
		if (!synaptics_validate_byte(psmouse, i, SYN_NEWABS_STRICT)) {
			psmouse_info(psmouse, "using relaxed packet validation\n");
			return SYN_NEWABS_RELAXED;
		}

	return SYN_NEWABS_STRICT;
}

static psmouse_ret_t synaptics_process_byte(struct psmouse *psmouse)
{
	struct synaptics_data *priv = psmouse->private;

	if (psmouse->pktcnt >= 6) { /* Full packet received */
		if (unlikely(priv->pkt_type == SYN_NEWABS))
			priv->pkt_type = synaptics_detect_pkt_type(psmouse);

		if (SYN_CAP_PASS_THROUGH(priv->capabilities) &&
		    synaptics_is_pt_packet(psmouse->packet)) {
			if (priv->pt_port)
				synaptics_pass_pt_packet(priv->pt_port, psmouse->packet);
		} else
			synaptics_process_packet(psmouse);

		return PSMOUSE_FULL_PACKET;
	}

	return synaptics_validate_byte(psmouse, psmouse->pktcnt - 1, priv->pkt_type) ?
		PSMOUSE_GOOD_DATA : PSMOUSE_BAD_DATA;
}

/*****************************************************************************
 *	Driver initialization/cleanup functions
 ****************************************************************************/
static void set_abs_position_params(struct input_dev *dev,
				    struct synaptics_data *priv, int x_code,
				    int y_code)
{
	int x_min = priv->x_min ?: XMIN_NOMINAL;
	int x_max = priv->x_max ?: XMAX_NOMINAL;
	int y_min = priv->y_min ?: YMIN_NOMINAL;
	int y_max = priv->y_max ?: YMAX_NOMINAL;
	int fuzz = SYN_CAP_REDUCED_FILTERING(priv->ext_cap_0c) ?
			SYN_REDUCED_FILTER_FUZZ : 0;

	input_set_abs_params(dev, x_code, x_min, x_max, fuzz, 0);
	input_set_abs_params(dev, y_code, y_min, y_max, fuzz, 0);
	input_abs_set_res(dev, x_code, priv->x_res);
	input_abs_set_res(dev, y_code, priv->y_res);
}

static void set_input_params(struct input_dev *dev, struct synaptics_data *priv)
{
	int i;

	__set_bit(INPUT_PROP_POINTER, dev->propbit);

	__set_bit(EV_ABS, dev->evbit);
	set_abs_position_params(dev, priv, ABS_X, ABS_Y);
	input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0);

	if (SYN_CAP_IMAGE_SENSOR(priv->ext_cap_0c)) {
		input_mt_init_slots(dev, 2);
		set_abs_position_params(dev, priv, ABS_MT_POSITION_X,
					ABS_MT_POSITION_Y);
		/* Image sensors can report per-contact pressure */
		input_set_abs_params(dev, ABS_MT_PRESSURE, 0, 255, 0, 0);

		/* Image sensors can signal 4 and 5 finger clicks */
		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
		__set_bit(BTN_TOOL_QUINTTAP, dev->keybit);
	} else if (SYN_CAP_ADV_GESTURE(priv->ext_cap_0c)) {
		/* Non-image sensors with AGM use semi-mt */
		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
		input_mt_init_slots(dev, 2);
		set_abs_position_params(dev, priv, ABS_MT_POSITION_X,
					ABS_MT_POSITION_Y);
	}

	if (SYN_CAP_PALMDETECT(priv->capabilities))
		input_set_abs_params(dev, ABS_TOOL_WIDTH, 0, 15, 0, 0);

	__set_bit(EV_KEY, dev->evbit);
	__set_bit(BTN_TOUCH, dev->keybit);
	__set_bit(BTN_TOOL_FINGER, dev->keybit);
	__set_bit(BTN_LEFT, dev->keybit);
	__set_bit(BTN_RIGHT, dev->keybit);

	if (SYN_CAP_MULTIFINGER(priv->capabilities)) {
		__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
		__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
	}

	if (SYN_CAP_MIDDLE_BUTTON(priv->capabilities))
		__set_bit(BTN_MIDDLE, dev->keybit);

	if (SYN_CAP_FOUR_BUTTON(priv->capabilities) ||
	    SYN_CAP_MIDDLE_BUTTON(priv->capabilities)) {
		__set_bit(BTN_FORWARD, dev->keybit);
		__set_bit(BTN_BACK, dev->keybit);
	}

	for (i = 0; i < SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap); i++)
		__set_bit(BTN_0 + i, dev->keybit);

	__clear_bit(EV_REL, dev->evbit);
	__clear_bit(REL_X, dev->relbit);
	__clear_bit(REL_Y, dev->relbit);

	if (SYN_CAP_CLICKPAD(priv->ext_cap_0c)) {
		__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
		/* Clickpads report only left button */
		__clear_bit(BTN_RIGHT, dev->keybit);
		__clear_bit(BTN_MIDDLE, dev->keybit);
	}
}

static void synaptics_disconnect(struct psmouse *psmouse)
{
	synaptics_reset(psmouse);
	kfree(psmouse->private);
	psmouse->private = NULL;
}

static int synaptics_reconnect(struct psmouse *psmouse)
{
	struct synaptics_data *priv = psmouse->private;
	struct synaptics_data old_priv = *priv;
	int retry = 0;
	int error;

	do {
		psmouse_reset(psmouse);
		error = synaptics_detect(psmouse, 0);
	} while (error && ++retry < 3);

	if (error)
		return -1;

	if (retry > 1)
		psmouse_dbg(psmouse, "reconnected after %d tries\n", retry);

	if (synaptics_query_hardware(psmouse)) {
		psmouse_err(psmouse, "Unable to query device.\n");
		return -1;
	}

	if (synaptics_set_absolute_mode(psmouse)) {
		psmouse_err(psmouse, "Unable to initialize device.\n");
		return -1;
	}

	if (synaptics_set_advanced_gesture_mode(psmouse)) {
		psmouse_err(psmouse,
			    "Advanced gesture mode reconnect failed.\n");
		return -1;
	}

	if (old_priv.identity != priv->identity ||
	    old_priv.model_id != priv->model_id ||
	    old_priv.capabilities != priv->capabilities ||
	    old_priv.ext_cap != priv->ext_cap) {
		psmouse_err(psmouse,
			    "hardware appears to be different: id(%ld-%ld), model(%ld-%ld), caps(%lx-%lx), ext(%lx-%lx).\n",
			    old_priv.identity, priv->identity,
			    old_priv.model_id, priv->model_id,
			    old_priv.capabilities, priv->capabilities,
			    old_priv.ext_cap, priv->ext_cap);
		return -1;
	}

	return 0;
}

static bool impaired_toshiba_kbc;

static const struct dmi_system_id __initconst toshiba_dmi_table[] = {
#if defined(CONFIG_DMI) && defined(CONFIG_X86)
	{
		/* Toshiba Satellite */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
		},
	},
	{
		/* Toshiba Dynabook */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
			DMI_MATCH(DMI_PRODUCT_NAME, "dynabook"),
		},
	},
	{
		/* Toshiba Portege M300 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
			DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE M300"),
		},

	},
	{
		/* Toshiba Portege M300 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Portable PC"),
			DMI_MATCH(DMI_PRODUCT_VERSION, "Version 1.0"),
		},

	},
#endif
	{ }
};

static bool broken_olpc_ec;

static const struct dmi_system_id __initconst olpc_dmi_table[] = {
#if defined(CONFIG_DMI) && defined(CONFIG_OLPC)
	{
		/* OLPC XO-1 or XO-1.5 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "OLPC"),
			DMI_MATCH(DMI_PRODUCT_NAME, "XO"),
		},
	},
#endif
	{ }
};

void __init synaptics_module_init(void)
{
	impaired_toshiba_kbc = dmi_check_system(toshiba_dmi_table);
	broken_olpc_ec = dmi_check_system(olpc_dmi_table);
}

int synaptics_init(struct psmouse *psmouse)
{
	struct synaptics_data *priv;

	/*
	 * The OLPC XO has issues with Synaptics' absolute mode; similarly to
	 * the HGPK, it quickly degrades and the hardware becomes jumpy and
	 * overly sensitive.  Not only that, but the constant packet spew
	 * (even at a lowered 40pps rate) overloads the EC such that key
	 * presses on the keyboard are missed.  Given all of that, don't
	 * even attempt to use Synaptics mode.  Relative mode seems to work
	 * just fine.
	 */
	if (broken_olpc_ec) {
		psmouse_info(psmouse,
			     "OLPC XO detected, not enabling Synaptics protocol.\n");
		return -ENODEV;
	}

	psmouse->private = priv = kzalloc(sizeof(struct synaptics_data), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	psmouse_reset(psmouse);

	if (synaptics_query_hardware(psmouse)) {
		psmouse_err(psmouse, "Unable to query device.\n");
		goto init_fail;
	}

	if (synaptics_set_absolute_mode(psmouse)) {
		psmouse_err(psmouse, "Unable to initialize device.\n");
		goto init_fail;
	}

	if (synaptics_set_advanced_gesture_mode(psmouse)) {
		psmouse_err(psmouse, "Advanced gesture mode init failed.\n");
		goto init_fail;
	}

	priv->pkt_type = SYN_MODEL_NEWABS(priv->model_id) ? SYN_NEWABS : SYN_OLDABS;

	psmouse_info(psmouse,
		     "Touchpad model: %ld, fw: %ld.%ld, id: %#lx, caps: %#lx/%#lx/%#lx\n",
		     SYN_ID_MODEL(priv->identity),
		     SYN_ID_MAJOR(priv->identity), SYN_ID_MINOR(priv->identity),
		     priv->model_id,
		     priv->capabilities, priv->ext_cap, priv->ext_cap_0c);

	set_input_params(psmouse->dev, priv);

	/*
	 * Encode touchpad model so that it can be used to set
	 * input device->id.version and be visible to userspace.
	 * Because version is __u16 we have to drop something.
	 * Hardware info bits seem to be good candidates as they
	 * are documented to be for Synaptics corp. internal use.
	 */
	psmouse->model = ((priv->model_id & 0x00ff0000) >> 8) |
			  (priv->model_id & 0x000000ff);

	psmouse->protocol_handler = synaptics_process_byte;
	psmouse->set_rate = synaptics_set_rate;
	psmouse->disconnect = synaptics_disconnect;
	psmouse->reconnect = synaptics_reconnect;
	psmouse->cleanup = synaptics_reset;
	psmouse->pktsize = 6;
	/* Synaptics can usually stay in sync without extra help */
	psmouse->resync_time = 0;

	if (SYN_CAP_PASS_THROUGH(priv->capabilities))
		synaptics_pt_create(psmouse);

	/*
	 * Toshiba's KBC seems to have trouble handling data from
	 * Synaptics at full rate.  Switch to a lower rate (roughly
	 * the same rate as a standard PS/2 mouse).
	 */
	if (psmouse->rate >= 80 && impaired_toshiba_kbc) {
		psmouse_info(psmouse,
			     "Toshiba %s detected, limiting rate to 40pps.\n",
			     dmi_get_system_info(DMI_PRODUCT_NAME));
		psmouse->rate = 40;
	}

	return 0;

 init_fail:
	kfree(priv);
	return -1;
}

bool synaptics_supported(void)
{
	return true;
}

#else /* CONFIG_MOUSE_PS2_SYNAPTICS */

void __init synaptics_module_init(void)
{
}

int synaptics_init(struct psmouse *psmouse)
{
	return -ENOSYS;
}

bool synaptics_supported(void)
{
	return false;
}

#endif /* CONFIG_MOUSE_PS2_SYNAPTICS */