path: root/drivers/input/mouse/synaptics.c

/*
 * 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/delay.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 0
#define XMAX 6143
#define YMIN 0
#define YMAX 6143
#define XMIN_NOMINAL 1472
#define XMAX_NOMINAL 5472
#define YMIN_NOMINAL 1408
#define YMAX_NOMINAL 4448

/* Size in bits of absolute position values reported by the hardware */
#define ABS_POS_BITS 13

/*
 * These values should represent the absolute maximum value that will
 * be reported for a positive position value. Some Synaptics firmware
 * uses this value to indicate a finger near the edge of the touchpad
 * whose precise position cannot be determined.
 *
 * At least one touchpad is known to report positions in excess of this
 * value which are actually negative values truncated to the 13-bit
 * reporting range. These values have never been observed to be lower
 * than 8184 (i.e. -8), so we treat all values greater than 8176 as
 * negative and any other value as positive.
 */
#define X_MAX_POSITIVE 8176
#define Y_MAX_POSITIVE 8176

/*****************************************************************************
 *	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
 ****************************************************************************/

/*
 * 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;
}

/*
 * 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 to