drivers/input/mouse/elantech.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * Elantech Touchpad driver (v6)
  *
  * Copyright (C) 2007-2009 Arjan Opmeer <arjan@opmeer.net>
  *
  * 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/delay.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/input.h>
 #include <linux/serio.h>
 #include <linux/libps2.h>
 #include "psmouse.h"
 #include "elantech.h"

 #define elantech_debug(format, arg...)				\
 	do {							\
 		if (etd->debug)					\
 			printk(KERN_DEBUG format, ##arg);	\
 	} while (0)

 static bool force_elantech;
 module_param_named(force_elantech, force_elantech, bool, 0644);
 MODULE_PARM_DESC(force_elantech, "Force the Elantech PS/2 protocol extension to be used, 1 = enabled, 0 = disabled (default).");

 /*
  * Send a Synaptics style sliced query command
  */
 static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
 				unsigned char *param)
 {
 	if (psmouse_sliced_command(psmouse, c) ||
 	    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
 		pr_err("elantech.c: synaptics_send_cmd query 0x%02x failed.\n", c);
 		return -1;
 	}

 	return 0;
 }

 /*
  * A retrying version of ps2_command
  */
 static int elantech_ps2_command(struct psmouse *psmouse,
 				unsigned char *param, int command)
 {
 	struct ps2dev *ps2dev = &psmouse->ps2dev;
 	struct elantech_data *etd = psmouse->private;
 	int rc;
 	int tries = ETP_PS2_COMMAND_TRIES;

 	do {
 		rc = ps2_command(ps2dev, param, command);
 		if (rc == 0)
 			break;
 		tries--;
 		elantech_debug("elantech.c: retrying ps2 command 0x%02x (%d).\n",
 			command, tries);
 		msleep(ETP_PS2_COMMAND_DELAY);
 	} while (tries > 0);

 	if (rc)
 		pr_err("elantech.c: ps2 command 0x%02x failed.\n", command);

 	return rc;
 }

 /*
  * Send an Elantech style special command to read a value from a register
  */
 static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
 				unsigned char *val)
 {
 	struct elantech_data *etd = psmouse->private;
 	unsigned char param[3];
 	int rc = 0;

 	if (reg < 0x10 || reg > 0x26)
 		return -1;

 	if (reg > 0x11 && reg < 0x20)
 		return -1;

 	switch (etd->hw_version) {
 	case 1:
 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) ||
 		    psmouse_sliced_command(psmouse, reg) ||
 		    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
 			rc = -1;
 		}
 		break;

 	case 2:
 		if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
 		    elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
 		    elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
 		    elantech_ps2_command(psmouse,  NULL, reg) ||
 		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
 			rc = -1;
 		}
 		break;
 	}

 	if (rc)
 		pr_err("elantech.c: failed to read register 0x%02x.\n", reg);
 	else
 		*val = param[0];

 	return rc;
 }

 /*
  * Send an Elantech style special command to write a register with a value
  */
 static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
 				unsigned char val)
 {
 	struct elantech_data *etd = psmouse->private;
 	int rc = 0;

 	if (reg < 0x10 || reg > 0x26)
 		return -1;

 	if (reg > 0x11 && reg < 0x20)
 		return -1;

 	switch (etd->hw_version) {
 	case 1:
 		if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) ||
 		    psmouse_sliced_command(psmouse, reg) ||
 		    psmouse_sliced_command(psmouse, val) ||
 		    ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
 			rc = -1;
 		}
 		break;

 	case 2:
 		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
 		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
 		    elantech_ps2_command(psmouse, NULL, reg) ||
 		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
 		    elantech_ps2_command(psmouse, NULL, val) ||
 		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
 			rc = -1;
 		}
 		break;
 	}

 	if (rc)
 		pr_err("elantech.c: failed to write register 0x%02x with value 0x%02x.\n",
 			reg, val);

 	return rc;
 }

 /*
  * Dump a complete mouse movement packet to the syslog
  */
 static void elantech_packet_dump(unsigned char *packet, int size)
 {
 	int	i;

 	printk(KERN_DEBUG "elantech.c: PS/2 packet [");
 	for (i = 0; i < size; i++)
 		printk("%s0x%02x ", (i) ? ", " : " ", packet[i]);
 	printk("]\n");
 }

 /*
  * Interpret complete data packets and report absolute mode input events for
  * hardware version 1. (4 byte packets)
  */
 static void elantech_report_absolute_v1(struct psmouse *psmouse)
 {
 	struct input_dev *dev = psmouse->dev;
 	struct elantech_data *etd = psmouse->private;
 	unsigned char *packet = psmouse->packet;
 	int fingers;
 	static int old_fingers;

 	if (etd->fw_version < 0x020000) {
 		/*
 		 * byte 0:  D   U  p1  p2   1  p3   R   L
 		 * byte 1:  f   0  th  tw  x9  x8  y9  y8
 		 */
 		fingers = ((packet[1] & 0x80) >> 7) +
 				((packet[1] & 0x30) >> 4);
 	} else {
 		/*
 		 * byte 0: n1  n0  p2  p1   1  p3   R   L
 		 * byte 1:  0   0   0   0  x9  x8  y9  y8
 		 */
 		fingers = (packet[0] & 0xc0) >> 6;
 	}

 	if (etd->jumpy_cursor) {
 		/* Discard packets that are likely to have bogus coordinates */
 		if (fingers > old_fingers) {
 			elantech_debug("elantech.c: discarding packet\n");
 			goto discard_packet_v1;
 		}
 	}

 	input_report_key(dev, BTN_TOUCH, fingers != 0);

 	/*
 	 * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
 	 * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
 	 */
 	if (fingers) {
 		input_report_abs(dev, ABS_X,
 			((packet[1] & 0x0c) << 6) | packet[2]);
 		input_report_abs(dev, ABS_Y,
 			ETP_YMAX_V1 - (((packet[1] & 0x03) << 8) | packet[3]));
 	}

 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);

 	if (etd->fw_version < 0x020000 &&
 	    (etd->capabilities & ETP_CAP_HAS_ROCKER)) {
 		/* rocker up */
 		input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
 		/* rocker down */
 		input_report_key(dev, BTN_BACK, packet[0] & 0x80);
 	}

 	input_sync(dev);

  discard_packet_v1:
 	old_fingers = fingers;
 }

 /*
  * Interpret complete data packets and report absolute mode input events for
  * hardware version 2. (6 byte packets)
  */
 static void elantech_report_absolute_v2(struct psmouse *psmouse)
 {
 	struct input_dev *dev = psmouse->dev;
 	unsigned char *packet = psmouse->packet;
 	int fingers, x1, y1, x2, y2;

 	/* byte 0: n1  n0   .   .   .   .   R   L */
 	fingers = (packet[0] & 0xc0) >> 6;
 	input_report_key(dev, BTN_TOUCH, fingers != 0);

 	switch (fingers) {
 	case 1:
 		/*
 		 * byte 1:  .   .   .   .   .  x10 x9  x8
 		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
 		 */
 		input_report_abs(dev, ABS_X,
 			((packet[1] & 0x07) << 8) | packet[2]);
 		/*
 		 * byte 4:  .   .   .   .   .   .  y9  y8
 		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
 		 */
 		input_report_abs(dev, ABS_Y,
 			ETP_YMAX_V2 - (((packet[4] & 0x03) << 8) | packet[5]));
 		break;

 	case 2:
 		/*
 		 * The coordinate of each finger is reported separately
 		 * with a lower resolution for two finger touches:
 		 * byte 0:  .   .  ay8 ax8  .   .   .   .
 		 * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
 		 */
 		x1 = ((packet[0] & 0x10) << 4) | packet[1];
 		/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
 		y1 = ETP_2FT_YMAX - (((packet[0] & 0x20) << 3) | packet[2]);
 		/*
 		 * byte 3:  .   .  by8 bx8  .   .   .   .
 		 * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
 		 */
 		x2 = ((packet[3] & 0x10) << 4) | packet[4];
 		/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
 		y2 = ETP_2FT_YMAX - (((packet[3] & 0x20) << 3) | packet[5]);
 		/*
 		 * For compatibility with the X Synaptics driver scale up
 		 * one coordinate and report as ordinary mouse movent
 		 */
 		input_report_abs(dev, ABS_X, x1 << 2);
 		input_report_abs(dev, ABS_Y, y1 << 2);
 		/*
 		 * For compatibility with the proprietary X Elantech driver
 		 * report both coordinates as hat coordinates
 		 */
 		input_report_abs(dev, ABS_HAT0X, x1);
 		input_report_abs(dev, ABS_HAT0Y, y1);
 		input_report_abs(dev, ABS_HAT1X, x2);
 		input_report_abs(dev, ABS_HAT1Y, y2);
 		break;
 	}

 	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
 	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
 	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
 	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
 	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);

 	input_sync(dev);
 }

 static int elantech_check_parity_v1(struct psmouse *psmouse)
 {
 	struct elantech_data *etd = psmouse->private;
 	unsigned char *packet = psmouse->packet;
 	unsigned char p1, p2, p3;

 	/* Parity bits are placed differently */
 	if (etd->fw_version < 0x020000) {
 		/* byte 0:  D   U  p1  p2   1  p3   R   L */
 		p1 = (packet[0] & 0x20) >> 5;
 		p2 = (packet[0] & 0x10) >> 4;
 	} else {
 		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
 		p1 = (packet[0] & 0x10) >> 4;
 		p2 = (packet[0] & 0x20) >> 5;
 	}

 	p3 = (packet[0] & 0x04) >> 2;

 	return etd->parity[packet[1]] == p1 &&
 	       etd->parity[packet[2]] == p2 &&
 	       etd->parity[packet[3]] == p3;
 }

 /*
  * Process byte stream from mouse and handle complete packets
  */
 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
 {
 	struct elantech_data *etd = psmouse->private;

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

 	if (etd->debug > 1)
 		elantech_packet_dump(psmouse->packet, psmouse->pktsize);

 	switch (etd->hw_version) {
 	case 1:
 		if (etd->paritycheck && !elantech_check_parity_v1(psmouse))
 			return PSMOUSE_BAD_DATA;

 		elantech_report_absolute_v1(psmouse);
 		break;

 	case 2:
 		/* We don't know how to check parity in protocol v2 */
 		elantech_report_absolute_v2(psmouse);
 		break;
 	}

 	return PSMOUSE_FULL_PACKET;
 }

 /*
  * Put the touchpad into absolute mode
  */
 static int elantech_set_absolute_mode(struct psmouse *psmouse)
 {
 	struct elantech_data *etd = psmouse->private;
 	unsigned char val;
 	int tries = ETP_READ_BACK_TRIES;
 	int rc = 0;

 	switch (etd->hw_version) {
 	case 1:
 		etd->reg_10 = 0x16;
 		etd->reg_11 = 0x8f;
 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
 		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
 			rc = -1;
 		}
 		break;

 	case 2:
 					/* Windows driver values */
 		etd->reg_10 = 0x54;
 		etd->reg_11 = 0x88;	/* 0x8a */
 		etd->reg_21 = 0x60;	/* 0x00 */
 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
 		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
 		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
 			rc = -1;
 			break;
 		}
 	}

 	if (rc == 0) {
 		/*
 		 * Read back reg 0x10. For hardware version 1 we must make
 		 * sure the absolute mode bit is set. For hardware version 2
 		 * the touchpad is probably initalising and not ready until
 		 * we read back the value we just wrote.
 		 */
 		do {
 			rc = elantech_read_reg(psmouse, 0x10, &val);
 			if (rc == 0)
 				break;
 			tries--;
 			elantech_debug("elantech.c: retrying read (%d).\n",
 					tries);
 			msleep(ETP_READ_BACK_DELAY);
 		} while (tries > 0);

 		if (rc) {
 			pr_err("elantech.c: failed to read back register 0x10.\n");
 		} else if (etd->hw_version == 1 &&
 			   !(val & ETP_R10_ABSOLUTE_MODE)) {
 			pr_err("elantech.c: touchpad refuses "
 				"to switch to absolute mode.\n");
 			rc = -1;
 		}
 	}

 	if (rc)
 		pr_err("elantech.c: failed to initialise registers.\n");

 	return rc;
 }

 /*
  * Set the appropriate event bits for the input subsystem
  */
 static void elantech_set_input_params(struct psmouse *psmouse)
 {
 	struct input_dev *dev = psmouse->dev;
 	struct elantech_data *etd = psmouse->private;

 	__set_bit(EV_KEY, dev->evbit);
 	__set_bit(EV_ABS, dev->evbit);
 	__clear_bit(EV_REL, dev->evbit);

 	__set_bit(BTN_LEFT, dev->keybit);
 	__set_bit(BTN_RIGHT, dev->keybit);

 	__set_bit(BTN_TOUCH, dev->keybit);
 	__set_bit(BTN_TOOL_FINGER, dev->keybit);
 	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
 	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);

 	switch (etd->hw_version) {
 	case 1:
 		/* Rocker button */
 		if (etd->fw_version < 0x020000 &&
 		    (etd->capabilities & ETP_CAP_HAS_ROCKER)) {
 			__set_bit(BTN_FORWARD, dev->keybit);
 			__set_bit(BTN_BACK, dev->keybit);
 		}
 		input_set_abs_params(dev, ABS_X, ETP_XMIN_V1, ETP_XMAX_V1, 0, 0);
 		input_set_abs_params(dev, ABS_Y, ETP_YMIN_V1, ETP_YMAX_V1, 0, 0);
 		break;

 	case 2:
 		input_set_abs_params(dev, ABS_X, ETP_XMIN_V2, ETP_XMAX_V2, 0, 0);
 		input_set_abs_params(dev, ABS_Y, ETP_YMIN_V2, ETP_YMAX_V2, 0, 0);
 		input_set_abs_params(dev, ABS_HAT0X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
 		input_set_abs_params(dev, ABS_HAT0Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
 		input_set_abs_params(dev, ABS_HAT1X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
 		input_set_abs_params(dev, ABS_HAT1Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
 		break;
 	}
 }

 struct elantech_attr_data {
 	size_t		field_offset;
 	unsigned char	reg;
 };

 /*
  * Display a register value by reading a sysfs entry
  */
 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
 					char *buf)
 {
 	struct elantech_data *etd = psmouse->private;
 	struct elantech_attr_data *attr = data;
 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
 	int rc = 0;

 	if (attr->reg)
 		rc = elantech_read_reg(psmouse, attr->reg, reg);

 	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
 }

 /*
  * Write a register value by writing a sysfs entry
  */
 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
 				     void *data, const char *buf, size_t count)
 {
 	struct elantech_data *etd = psmouse->private;
 	struct elantech_attr_data *attr = data;
 	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
 	unsigned long value;
 	int err;

 	err = strict_strtoul(buf, 16, &value);
 	if (err)
 		return err;

 	if (value > 0xff)
 		return -EINVAL;

 	/* Do we need to preserve some bits for version 2 hardware too? */
 	if (etd->hw_version == 1) {
 		if (attr->reg == 0x10)
 			/* Force absolute mode always on */
 			value |= ETP_R10_ABSOLUTE_MODE;
 		else if (attr->reg == 0x11)
 			/* Force 4 byte mode always on */
 			value |= ETP_R11_4_BYTE_MODE;
 	}

 	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
 		*reg = value;

 	return count;
 }

 #define ELANTECH_INT_ATTR(_name, _register)				\
 	static struct elantech_attr_data elantech_attr_##_name = {	\
 		.field_offset = offsetof(struct elantech_data, _name),	\
 		.reg = _register,					\
 	};								\
 	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,			\
 			    &elantech_attr_##_name,			\
 			    elantech_show_int_attr,			\
 			    elantech_set_int_attr)

 ELANTECH_INT_ATTR(reg_10, 0x10);
 ELANTECH_INT_ATTR(reg_11, 0x11);
 ELANTECH_INT_ATTR(reg_20, 0x20);
 ELANTECH_INT_ATTR(reg_21, 0x21);
 ELANTECH_INT_ATTR(reg_22, 0x22);
 ELANTECH_INT_ATTR(reg_23, 0x23);
 ELANTECH_INT_ATTR(reg_24, 0x24);
 ELANTECH_INT_ATTR(reg_25, 0x25);
 ELANTECH_INT_ATTR(reg_26, 0x26);
 ELANTECH_INT_ATTR(debug, 0);
 ELANTECH_INT_ATTR(paritycheck, 0);

 static struct attribute *elantech_attrs[] = {
 	&psmouse_attr_reg_10.dattr.attr,
 	&psmouse_attr_reg_11.dattr.attr,
 	&psmouse_attr_reg_20.dattr.attr,
 	&psmouse_attr_reg_21.dattr.attr,
 	&psmouse_attr_reg_22.dattr.attr,
 	&psmouse_attr_reg_23.dattr.attr,
 	&psmouse_attr_reg_24.dattr.attr,
 	&psmouse_attr_reg_25.dattr.attr,
 	&psmouse_attr_reg_26.dattr.attr,
 	&psmouse_attr_debug.dattr.attr,
 	&psmouse_attr_paritycheck.dattr.attr,
 	NULL
 };

 static struct attribute_group elantech_attr_group = {
 	.attrs = elantech_attrs,
 };

 /*
  * Use magic knock to detect Elantech touchpad
  */
 int elantech_detect(struct psmouse *psmouse, bool set_properties)
 {
 	struct ps2dev *ps2dev = &psmouse->ps2dev;
 	unsigned char param[3];

 	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);

 	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
 	    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)) {
 		pr_debug("elantech.c: sending Elantech magic knock failed.\n");
 		return -1;
 	}

 	/*
 	 * Report this in case there are Elantech models that use a different
 	 * set of magic numbers
 	 */
 	if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
 		pr_debug("elantech.c: "
 			 "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
 			 param[0], param[1], param[2]);
 		return -1;
 	}

 	/*
 	 * Query touchpad's firmware version and see if it reports known
 	 * value to avoid mis-detection. Logitech mice are known to respond
 	 * to Elantech magic knock and there might be more.
 	 */
 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
 		pr_debug("elantech.c: failed to query firmware version.\n");
 		return -1;
 	}

 	pr_debug("elantech.c: Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
 		 param[0], param[1], param[2]);

 	if (param[0] == 0 || param[1] != 0) {
 		if (!force_elantech) {
 			pr_debug("elantech.c: Probably not a real Elantech touchpad. Aborting.\n");
 			return -1;
 		}

 		pr_debug("elantech.c: Probably not a real Elantech touchpad. Enabling anyway due to force_elantech.\n");
 	}

 	if (set_properties) {
 		psmouse->vendor = "Elantech";
 		psmouse->name = "Touchpad";
 	}

 	return 0;
 }

 /*
  * Clean up sysfs entries when disconnecting
  */
 static void elantech_disconnect(struct psmouse *psmouse)
 {
 	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
 			   &elantech_attr_group);
 	kfree(psmouse->private);
 	psmouse->private = NULL;
 }

 /*
  * Put the touchpad back into absolute mode when reconnecting
  */
 static int elantech_reconnect(struct psmouse *psmouse)
 {
 	if (elantech_detect(psmouse, 0))
 		return -1;

 	if (elantech_set_absolute_mode(psmouse)) {
 		pr_err("elantech.c: failed to put touchpad back into absolute mode.\n");
 		return -1;
 	}

 	return 0;
 }

 /*
  * Initialize the touchpad and create sysfs entries
  */
 int elantech_init(struct psmouse *psmouse)
 {
 	struct elantech_data *etd;
 	int i, error;
 	unsigned char param[3];

 	psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
 	if (!etd)
 		return -1;

 	etd->parity[0] = 1;
 	for (i = 1; i < 256; i++)
 		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;

 	/*
 	 * Do the version query again so we can store the result
 	 */
 	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
 		pr_err("elantech.c: failed to query firmware version.\n");
 		goto init_fail;
 	}

 	etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];

 	/*
 	 * Assume every version greater than this is new EeePC style
 	 * hardware with 6 byte packets
 	 */
 	if (etd->fw_version >= 0x020030) {
 		etd->hw_version = 2;
 		/* For now show extra debug information */
 		etd->debug = 1;
 		/* Don't know how to do parity checking for version 2 */
 		etd->paritycheck = 0;
 	} else {
 		etd->hw_version = 1;
 		etd->paritycheck = 1;
 	}

 	pr_info("elantech.c: assuming hardware version %d, firmware version %d.%d.%d\n",
 		etd->hw_version, param[0], param[1], param[2]);

 	if (synaptics_send_cmd(psmouse, ETP_CAPABILITIES_QUERY, param)) {
 		pr_err("elantech.c: failed to query capabilities.\n");
 		goto init_fail;
 	}
 	pr_info("elantech.c: Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
 		param[0], param[1], param[2]);
 	etd->capabilities = param[0];

 	/*
 	 * This firmware seems to suffer from misreporting coordinates when
 	 * a touch action starts causing the mouse cursor or scrolled page
 	 * to jump. Enable a workaround.
 	 */
 	if (etd->fw_version == 0x020022) {
 		pr_info("elantech.c: firmware version 2.0.34 detected, "
 			"enabling jumpy cursor workaround\n");
 		etd->jumpy_cursor = 1;
 	}

 	if (elantech_set_absolute_mode(psmouse)) {
 		pr_err("elantech.c: failed to put touchpad into absolute mode.\n");
 		goto init_fail;
 	}

 	elantech_set_input_params(psmouse);

 	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
 				   &elantech_attr_group);
 	if (error) {
 		pr_err("elantech.c: failed to create sysfs attributes, error: %d.\n",
 			error);
 		goto init_fail;
 	}

 	psmouse->protocol_handler = elantech_process_byte;
 	psmouse->disconnect = elantech_disconnect;
 	psmouse->reconnect = elantech_reconnect;
 	psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;

 	return 0;

  init_fail:
 	kfree(etd);
 	return -1;
 }
	/*
	* Elantech Touchpad driver (v6)
	*
	* Copyright (C) 2007-2009 Arjan Opmeer <arjan@opmeer.net>
	*
	* 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/delay.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/input.h>
	#include <linux/serio.h>
	#include <linux/libps2.h>
	#include "psmouse.h"
	#include "elantech.h"

	#define elantech_debug(format, arg...) \
	do { \
	if (etd->debug) \
	printk(KERN_DEBUG format, ##arg); \
	} while (0)

	static bool force_elantech;
	module_param_named(force_elantech, force_elantech, bool, 0644);
	MODULE_PARM_DESC(force_elantech, "Force the Elantech PS/2 protocol extension to be used, 1 = enabled, 0 = disabled (default).");

	/*
	* Send a Synaptics style sliced query command
	*/
	static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
	unsigned char *param)
	{
	if (psmouse_sliced_command(psmouse, c) \|\|
	ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
	pr_err("elantech.c: synaptics_send_cmd query 0x%02x failed.\n", c);
	return -1;
	}

	return 0;
	}

	/*
	* A retrying version of ps2_command
	*/
	static int elantech_ps2_command(struct psmouse *psmouse,
	unsigned char *param, int command)
	{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	struct elantech_data *etd = psmouse->private;
	int rc;
	int tries = ETP_PS2_COMMAND_TRIES;

	do {
	rc = ps2_command(ps2dev, param, command);
	if (rc == 0)
	break;
	tries--;
	elantech_debug("elantech.c: retrying ps2 command 0x%02x (%d).\n",
	command, tries);
	msleep(ETP_PS2_COMMAND_DELAY);
	} while (tries > 0);

	if (rc)
	pr_err("elantech.c: ps2 command 0x%02x failed.\n", command);

	return rc;
	}

	/*
	* Send an Elantech style special command to read a value from a register
	*/
	static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
	unsigned char *val)
	{
	struct elantech_data *etd = psmouse->private;
	unsigned char param[3];
	int rc = 0;

	if (reg < 0x10 \|\| reg > 0x26)
	return -1;

	if (reg > 0x11 && reg < 0x20)
	return -1;

	switch (etd->hw_version) {
	case 1:
	if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) \|\|
	psmouse_sliced_command(psmouse, reg) \|\|
	ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
	rc = -1;
	}
	break;

	case 2:
	if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) \|\|
	elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READ) \|\|
	elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) \|\|
	elantech_ps2_command(psmouse, NULL, reg) \|\|
	elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
	rc = -1;
	}
	break;
	}

	if (rc)
	pr_err("elantech.c: failed to read register 0x%02x.\n", reg);
	else
	*val = param[0];

	return rc;
	}

	/*
	* Send an Elantech style special command to write a register with a value
	*/
	static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
	unsigned char val)
	{
	struct elantech_data *etd = psmouse->private;
	int rc = 0;

	if (reg < 0x10 \|\| reg > 0x26)
	return -1;

	if (reg > 0x11 && reg < 0x20)
	return -1;

	switch (etd->hw_version) {
	case 1:
	if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) \|\|
	psmouse_sliced_command(psmouse, reg) \|\|
	psmouse_sliced_command(psmouse, val) \|\|
	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
	rc = -1;
	}
	break;

	case 2:
	if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) \|\|
	elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) \|\|
	elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) \|\|
	elantech_ps2_command(psmouse, NULL, reg) \|\|
	elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) \|\|
	elantech_ps2_command(psmouse, NULL, val) \|\|
	elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
	rc = -1;
	}
	break;
	}

	if (rc)
	pr_err("elantech.c: failed to write register 0x%02x with value 0x%02x.\n",
	reg, val);

	return rc;
	}

	/*
	* Dump a complete mouse movement packet to the syslog
	*/
	static void elantech_packet_dump(unsigned char *packet, int size)
	{
	int i;

	printk(KERN_DEBUG "elantech.c: PS/2 packet [");
	for (i = 0; i < size; i++)
	printk("%s0x%02x ", (i) ? ", " : " ", packet[i]);
	printk("]\n");
	}

	/*
	* Interpret complete data packets and report absolute mode input events for
	* hardware version 1. (4 byte packets)
	*/
	static void elantech_report_absolute_v1(struct psmouse *psmouse)
	{
	struct input_dev *dev = psmouse->dev;
	struct elantech_data *etd = psmouse->private;
	unsigned char *packet = psmouse->packet;
	int fingers;
	static int old_fingers;

	if (etd->fw_version < 0x020000) {
	/*
	* byte 0: D U p1 p2 1 p3 R L
	* byte 1: f 0 th tw x9 x8 y9 y8
	*/
	fingers = ((packet[1] & 0x80) >> 7) +
	((packet[1] & 0x30) >> 4);
	} else {
	/*
	* byte 0: n1 n0 p2 p1 1 p3 R L
	* byte 1: 0 0 0 0 x9 x8 y9 y8
	*/
	fingers = (packet[0] & 0xc0) >> 6;
	}

	if (etd->jumpy_cursor) {
	/* Discard packets that are likely to have bogus coordinates */
	if (fingers > old_fingers) {
	elantech_debug("elantech.c: discarding packet\n");
	goto discard_packet_v1;
	}
	}

	input_report_key(dev, BTN_TOUCH, fingers != 0);

	/*
	* byte 2: x7 x6 x5 x4 x3 x2 x1 x0
	* byte 3: y7 y6 y5 y4 y3 y2 y1 y0
	*/
	if (fingers) {
	input_report_abs(dev, ABS_X,
	((packet[1] & 0x0c) << 6) \| packet[2]);
	input_report_abs(dev, ABS_Y,
	ETP_YMAX_V1 - (((packet[1] & 0x03) << 8) \| packet[3]));
	}

	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);

	if (etd->fw_version < 0x020000 &&
	(etd->capabilities & ETP_CAP_HAS_ROCKER)) {
	/* rocker up */
	input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
	/* rocker down */
	input_report_key(dev, BTN_BACK, packet[0] & 0x80);
	}

	input_sync(dev);

	discard_packet_v1:
	old_fingers = fingers;
	}

	/*
	* Interpret complete data packets and report absolute mode input events for
	* hardware version 2. (6 byte packets)
	*/
	static void elantech_report_absolute_v2(struct psmouse *psmouse)
	{
	struct input_dev *dev = psmouse->dev;
	unsigned char *packet = psmouse->packet;
	int fingers, x1, y1, x2, y2;

	/* byte 0: n1 n0 . . . . R L */
	fingers = (packet[0] & 0xc0) >> 6;
	input_report_key(dev, BTN_TOUCH, fingers != 0);

	switch (fingers) {
	case 1:
	/*
	* byte 1: . . . . . x10 x9 x8
	* byte 2: x7 x6 x5 x4 x4 x2 x1 x0
	*/
	input_report_abs(dev, ABS_X,
	((packet[1] & 0x07) << 8) \| packet[2]);
	/*
	* byte 4: . . . . . . y9 y8
	* byte 5: y7 y6 y5 y4 y3 y2 y1 y0
	*/
	input_report_abs(dev, ABS_Y,
	ETP_YMAX_V2 - (((packet[4] & 0x03) << 8) \| packet[5]));
	break;

	case 2:
	/*
	* The coordinate of each finger is reported separately
	* with a lower resolution for two finger touches:
	* byte 0: . . ay8 ax8 . . . .
	* byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
	*/
	x1 = ((packet[0] & 0x10) << 4) \| packet[1];
	/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
	y1 = ETP_2FT_YMAX - (((packet[0] & 0x20) << 3) \| packet[2]);
	/*
	* byte 3: . . by8 bx8 . . . .
	* byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
	*/
	x2 = ((packet[3] & 0x10) << 4) \| packet[4];
	/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
	y2 = ETP_2FT_YMAX - (((packet[3] & 0x20) << 3) \| packet[5]);
	/*
	* For compatibility with the X Synaptics driver scale up
	* one coordinate and report as ordinary mouse movent
	*/
	input_report_abs(dev, ABS_X, x1 << 2);
	input_report_abs(dev, ABS_Y, y1 << 2);
	/*
	* For compatibility with the proprietary X Elantech driver
	* report both coordinates as hat coordinates
	*/
	input_report_abs(dev, ABS_HAT0X, x1);
	input_report_abs(dev, ABS_HAT0Y, y1);
	input_report_abs(dev, ABS_HAT1X, x2);
	input_report_abs(dev, ABS_HAT1Y, y2);
	break;
	}

	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);

	input_sync(dev);
	}

	static int elantech_check_parity_v1(struct psmouse *psmouse)
	{
	struct elantech_data *etd = psmouse->private;
	unsigned char *packet = psmouse->packet;
	unsigned char p1, p2, p3;

	/* Parity bits are placed differently */
	if (etd->fw_version < 0x020000) {
	/* byte 0: D U p1 p2 1 p3 R L */
	p1 = (packet[0] & 0x20) >> 5;
	p2 = (packet[0] & 0x10) >> 4;
	} else {
	/* byte 0: n1 n0 p2 p1 1 p3 R L */
	p1 = (packet[0] & 0x10) >> 4;
	p2 = (packet[0] & 0x20) >> 5;
	}

	p3 = (packet[0] & 0x04) >> 2;

	return etd->parity[packet[1]] == p1 &&
	etd->parity[packet[2]] == p2 &&
	etd->parity[packet[3]] == p3;
	}

	/*
	* Process byte stream from mouse and handle complete packets
	*/
	static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
	{
	struct elantech_data *etd = psmouse->private;

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

	if (etd->debug > 1)
	elantech_packet_dump(psmouse->packet, psmouse->pktsize);

	switch (etd->hw_version) {
	case 1:
	if (etd->paritycheck && !elantech_check_parity_v1(psmouse))
	return PSMOUSE_BAD_DATA;

	elantech_report_absolute_v1(psmouse);
	break;

	case 2:
	/* We don't know how to check parity in protocol v2 */
	elantech_report_absolute_v2(psmouse);
	break;
	}

	return PSMOUSE_FULL_PACKET;
	}

	/*
	* Put the touchpad into absolute mode
	*/
	static int elantech_set_absolute_mode(struct psmouse *psmouse)
	{
	struct elantech_data *etd = psmouse->private;
	unsigned char val;
	int tries = ETP_READ_BACK_TRIES;
	int rc = 0;

	switch (etd->hw_version) {
	case 1:
	etd->reg_10 = 0x16;
	etd->reg_11 = 0x8f;
	if (elantech_write_reg(psmouse, 0x10, etd->reg_10) \|\|
	elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
	rc = -1;
	}
	break;

	case 2:
	/* Windows driver values */
	etd->reg_10 = 0x54;
	etd->reg_11 = 0x88; /* 0x8a */
	etd->reg_21 = 0x60; /* 0x00 */
	if (elantech_write_reg(psmouse, 0x10, etd->reg_10) \|\|
	elantech_write_reg(psmouse, 0x11, etd->reg_11) \|\|
	elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
	rc = -1;
	break;
	}
	}

	if (rc == 0) {
	/*
	* Read back reg 0x10. For hardware version 1 we must make
	* sure the absolute mode bit is set. For hardware version 2
	* the touchpad is probably initalising and not ready until
	* we read back the value we just wrote.
	*/
	do {
	rc = elantech_read_reg(psmouse, 0x10, &val);
	if (rc == 0)
	break;
	tries--;
	elantech_debug("elantech.c: retrying read (%d).\n",
	tries);
	msleep(ETP_READ_BACK_DELAY);
	} while (tries > 0);

	if (rc) {
	pr_err("elantech.c: failed to read back register 0x10.\n");
	} else if (etd->hw_version == 1 &&
	!(val & ETP_R10_ABSOLUTE_MODE)) {
	pr_err("elantech.c: touchpad refuses "
	"to switch to absolute mode.\n");
	rc = -1;
	}
	}

	if (rc)
	pr_err("elantech.c: failed to initialise registers.\n");

	return rc;
	}

	/*
	* Set the appropriate event bits for the input subsystem
	*/
	static void elantech_set_input_params(struct psmouse *psmouse)
	{
	struct input_dev *dev = psmouse->dev;
	struct elantech_data *etd = psmouse->private;

	__set_bit(EV_KEY, dev->evbit);
	__set_bit(EV_ABS, dev->evbit);
	__clear_bit(EV_REL, dev->evbit);

	__set_bit(BTN_LEFT, dev->keybit);
	__set_bit(BTN_RIGHT, dev->keybit);

	__set_bit(BTN_TOUCH, dev->keybit);
	__set_bit(BTN_TOOL_FINGER, dev->keybit);
	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);

	switch (etd->hw_version) {
	case 1:
	/* Rocker button */
	if (etd->fw_version < 0x020000 &&
	(etd->capabilities & ETP_CAP_HAS_ROCKER)) {
	__set_bit(BTN_FORWARD, dev->keybit);
	__set_bit(BTN_BACK, dev->keybit);
	}
	input_set_abs_params(dev, ABS_X, ETP_XMIN_V1, ETP_XMAX_V1, 0, 0);
	input_set_abs_params(dev, ABS_Y, ETP_YMIN_V1, ETP_YMAX_V1, 0, 0);
	break;

	case 2:
	input_set_abs_params(dev, ABS_X, ETP_XMIN_V2, ETP_XMAX_V2, 0, 0);
	input_set_abs_params(dev, ABS_Y, ETP_YMIN_V2, ETP_YMAX_V2, 0, 0);
	input_set_abs_params(dev, ABS_HAT0X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
	input_set_abs_params(dev, ABS_HAT0Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
	input_set_abs_params(dev, ABS_HAT1X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
	input_set_abs_params(dev, ABS_HAT1Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
	break;
	}
	}

	struct elantech_attr_data {
	size_t field_offset;
	unsigned char reg;
	};

	/*
	* Display a register value by reading a sysfs entry
	*/
	static ssize_t elantech_show_int_attr(struct psmouse psmouse, void data,
	char *buf)
	{
	struct elantech_data *etd = psmouse->private;
	struct elantech_attr_data *attr = data;
	unsigned char reg = (unsigned char ) etd + attr->field_offset;
	int rc = 0;

	if (attr->reg)
	rc = elantech_read_reg(psmouse, attr->reg, reg);

	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
	}

	/*
	* Write a register value by writing a sysfs entry
	*/
	static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
	void data, const char buf, size_t count)
	{
	struct elantech_data *etd = psmouse->private;
	struct elantech_attr_data *attr = data;
	unsigned char reg = (unsigned char ) etd + attr->field_offset;
	unsigned long value;
	int err;

	err = strict_strtoul(buf, 16, &value);
	if (err)
	return err;

	if (value > 0xff)
	return -EINVAL;

	/* Do we need to preserve some bits for version 2 hardware too? */
	if (etd->hw_version == 1) {
	if (attr->reg == 0x10)
	/* Force absolute mode always on */
	value \|= ETP_R10_ABSOLUTE_MODE;
	else if (attr->reg == 0x11)
	/* Force 4 byte mode always on */
	value \|= ETP_R11_4_BYTE_MODE;
	}

	if (!attr->reg \|\| elantech_write_reg(psmouse, attr->reg, value) == 0)
	*reg = value;

	return count;
	}

	#define ELANTECH_INT_ATTR(_name, _register) \
	static struct elantech_attr_data elantech_attr_##_name = { \
	.field_offset = offsetof(struct elantech_data, _name), \
	.reg = _register, \
	}; \
	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR \| S_IRUGO, \
	&elantech_attr_##_name, \
	elantech_show_int_attr, \
	elantech_set_int_attr)

	ELANTECH_INT_ATTR(reg_10, 0x10);
	ELANTECH_INT_ATTR(reg_11, 0x11);
	ELANTECH_INT_ATTR(reg_20, 0x20);
	ELANTECH_INT_ATTR(reg_21, 0x21);
	ELANTECH_INT_ATTR(reg_22, 0x22);
	ELANTECH_INT_ATTR(reg_23, 0x23);
	ELANTECH_INT_ATTR(reg_24, 0x24);
	ELANTECH_INT_ATTR(reg_25, 0x25);
	ELANTECH_INT_ATTR(reg_26, 0x26);
	ELANTECH_INT_ATTR(debug, 0);
	ELANTECH_INT_ATTR(paritycheck, 0);

	static struct attribute *elantech_attrs[] = {
	&psmouse_attr_reg_10.dattr.attr,
	&psmouse_attr_reg_11.dattr.attr,
	&psmouse_attr_reg_20.dattr.attr,
	&psmouse_attr_reg_21.dattr.attr,
	&psmouse_attr_reg_22.dattr.attr,
	&psmouse_attr_reg_23.dattr.attr,
	&psmouse_attr_reg_24.dattr.attr,
	&psmouse_attr_reg_25.dattr.attr,
	&psmouse_attr_reg_26.dattr.attr,
	&psmouse_attr_debug.dattr.attr,
	&psmouse_attr_paritycheck.dattr.attr,
	NULL
	};

	static struct attribute_group elantech_attr_group = {
	.attrs = elantech_attrs,
	};

	/*
	* Use magic knock to detect Elantech touchpad
	*/
	int elantech_detect(struct psmouse *psmouse, bool set_properties)
	{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	unsigned char param[3];

	ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);

	if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) \|\|
	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)) {
	pr_debug("elantech.c: sending Elantech magic knock failed.\n");
	return -1;
	}

	/*
	* Report this in case there are Elantech models that use a different
	* set of magic numbers
	*/
	if (param[0] != 0x3c \|\| param[1] != 0x03 \|\| param[2] != 0xc8) {
	pr_debug("elantech.c: "
	"unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
	param[0], param[1], param[2]);
	return -1;
	}

	/*
	* Query touchpad's firmware version and see if it reports known
	* value to avoid mis-detection. Logitech mice are known to respond
	* to Elantech magic knock and there might be more.
	*/
	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
	pr_debug("elantech.c: failed to query firmware version.\n");
	return -1;
	}

	pr_debug("elantech.c: Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
	param[0], param[1], param[2]);

	if (param[0] == 0 \|\| param[1] != 0) {
	if (!force_elantech) {
	pr_debug("elantech.c: Probably not a real Elantech touchpad. Aborting.\n");
	return -1;
	}

	pr_debug("elantech.c: Probably not a real Elantech touchpad. Enabling anyway due to force_elantech.\n");
	}

	if (set_properties) {
	psmouse->vendor = "Elantech";
	psmouse->name = "Touchpad";
	}

	return 0;
	}

	/*
	* Clean up sysfs entries when disconnecting
	*/
	static void elantech_disconnect(struct psmouse *psmouse)
	{
	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
	&elantech_attr_group);
	kfree(psmouse->private);
	psmouse->private = NULL;
	}

	/*
	* Put the touchpad back into absolute mode when reconnecting
	*/
	static int elantech_reconnect(struct psmouse *psmouse)
	{
	if (elantech_detect(psmouse, 0))
	return -1;

	if (elantech_set_absolute_mode(psmouse)) {
	pr_err("elantech.c: failed to put touchpad back into absolute mode.\n");
	return -1;
	}

	return 0;
	}

	/*
	* Initialize the touchpad and create sysfs entries
	*/
	int elantech_init(struct psmouse *psmouse)
	{
	struct elantech_data *etd;
	int i, error;
	unsigned char param[3];

	psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
	if (!etd)
	return -1;

	etd->parity[0] = 1;
	for (i = 1; i < 256; i++)
	etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;

	/*
	* Do the version query again so we can store the result
	*/
	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
	pr_err("elantech.c: failed to query firmware version.\n");
	goto init_fail;
	}

	etd->fw_version = (param[0] << 16) \| (param[1] << 8) \| param[2];

	/*
	* Assume every version greater than this is new EeePC style
	* hardware with 6 byte packets
	*/
	if (etd->fw_version >= 0x020030) {
	etd->hw_version = 2;
	/* For now show extra debug information */
	etd->debug = 1;
	/* Don't know how to do parity checking for version 2 */
	etd->paritycheck = 0;
	} else {
	etd->hw_version = 1;
	etd->paritycheck = 1;
	}

	pr_info("elantech.c: assuming hardware version %d, firmware version %d.%d.%d\n",
	etd->hw_version, param[0], param[1], param[2]);

	if (synaptics_send_cmd(psmouse, ETP_CAPABILITIES_QUERY, param)) {
	pr_err("elantech.c: failed to query capabilities.\n");
	goto init_fail;
	}
	pr_info("elantech.c: Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
	param[0], param[1], param[2]);
	etd->capabilities = param[0];

	/*
	* This firmware seems to suffer from misreporting coordinates when
	* a touch action starts causing the mouse cursor or scrolled page
	* to jump. Enable a workaround.
	*/
	if (etd->fw_version == 0x020022) {
	pr_info("elantech.c: firmware version 2.0.34 detected, "
	"enabling jumpy cursor workaround\n");
	etd->jumpy_cursor = 1;
	}

	if (elantech_set_absolute_mode(psmouse)) {
	pr_err("elantech.c: failed to put touchpad into absolute mode.\n");
	goto init_fail;
	}

	elantech_set_input_params(psmouse);

	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
	&elantech_attr_group);
	if (error) {
	pr_err("elantech.c: failed to create sysfs attributes, error: %d.\n",
	error);
	goto init_fail;
	}

	psmouse->protocol_handler = elantech_process_byte;
	psmouse->disconnect = elantech_disconnect;
	psmouse->reconnect = elantech_reconnect;
	psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;

	return 0;

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