Input: psmouse - add support for Elantech touchpads

This is version 5 of the driver. Relative mode support has been dropped (users wishing to use touchpad in relative mode can use standard PS/2 protocol emulation done in hardware). The driver supports both original version of Elantech protocol and the newer one used by touchpads installed in EeePC. Signed-off-by: Arjan Opmeer <arjan@opmeer.net> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: psmouse - add support for Elantech touchpads
This is version 5 of the driver. Relative mode support has been dropped (users wishing to use touchpad in relative mode can use standard PS/2 protocol emulation done in hardware). The driver supports both original version of Elantech protocol and the newer one used by touchpads installed in EeePC. Signed-off-by: Arjan Opmeer <arjan@opmeer.net> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Arjan Opmeer · Dmitry Torokhov
1 parent 2c6f2cb83b
Showing 7 changed files with 1251 additions and 2 deletions Side-by-side Diff
Documentation/input/elantech.txt
drivers/input/mouse/Kconfig
drivers/input/mouse/Makefile
drivers/input/mouse/elantech.c
drivers/input/mouse/elantech.h
drivers/input/mouse/psmouse-base.c
drivers/input/mouse/psmouse.h
+Elantech Touchpad Driver
+========================
+
+	Copyright (C) 2007-2008 Arjan Opmeer <arjan@opmeer.net>
+
+	Extra information for hardware version 1 found and
+	provided by Steve Havelka
+
+	Version 2 (EeePC) hardware support based on patches
+	received from Woody at Xandros and forwarded to me
+	by user StewieGriffin at the eeeuser.com forum
+
+
+Contents
+~~~~~~~~
+
+ 1. Introduction
+ 2. Extra knobs
+ 3. Hardware version 1
+    3.1 Registers
+    3.2 Native relative mode 4 byte packet format
+    3.3 Native absolute mode 4 byte packet format
+ 4. Hardware version 2
+    4.1 Registers
+    4.2 Native absolute mode 6 byte packet format
+        4.2.1 One finger touch
+        4.2.2 Two finger touch
+
+
+
+1. Introduction
+   ~~~~~~~~~~~~
+
+Currently the Linux Elantech touchpad driver is aware of two different
+hardware versions unimaginatively called version 1 and version 2. Version 1
+is found in "older" laptops and uses 4 bytes per packet. Version 2 seems to
+be introduced with the EeePC and uses 6 bytes per packet.
+
+The driver tries to support both hardware versions and should be compatible
+with the Xorg Synaptics touchpad driver and its graphical configuration
+utilities.
+
+Additionally the operation of the touchpad can be altered by adjusting the
+contents of some of its internal registers. These registers are represented
+by the driver as sysfs entries under /sys/bus/serio/drivers/psmouse/serio?
+that can be read from and written to.
+
+Currently only the registers for hardware version 1 are somewhat understood.
+Hardware version 2 seems to use some of the same registers but it is not
+known whether the bits in the registers represent the same thing or might
+have changed their meaning.
+
+On top of that, some register settings have effect only when the touchpad is
+in relative mode and not in absolute mode. As the Linux Elantech touchpad
+driver always puts the hardware into absolute mode not all information
+mentioned below can be used immediately. But because there is no freely
+available Elantech documentation the information is provided here anyway for
+completeness sake.
+
+
+/////////////////////////////////////////////////////////////////////////////
+
+
+2. Extra knobs
+   ~~~~~~~~~~~
+
+Currently the Linux Elantech touchpad driver provides two extra knobs under
+/sys/bus/serio/drivers/psmouse/serio? for the user.
+
+* debug
+
+   Turn different levels of debugging ON or OFF.
+
+   By echoing "0" to this file all debugging will be turned OFF.
+
+   Currently a value of "1" will turn on some basic debugging and a value of
+   "2" will turn on packet debugging. For hardware version 1 the default is
+   OFF. For version 2 the default is "1".
+
+   Turning packet debugging on will make the driver dump every packet
+   received to the syslog before processing it. Be warned that this can
+   generate quite a lot of data!
+
+* paritycheck
+
+   Turns parity checking ON or OFF.
+
+   By echoing "0" to this file parity checking will be turned OFF. Any
+   non-zero value will turn it ON. For hardware version 1 the default is ON.
+   For version 2 the default it is OFF.
+
+   Hardware version 1 provides basic data integrity verification by
+   calculating a parity bit for the last 3 bytes of each packet. The driver
+   can check these bits and reject any packet that appears corrupted. Using
+   this knob you can bypass that check.
+
+   It is not known yet whether hardware version 2 provides the same parity
+   bits. Hence checking is disabled by default. Currently even turning it on
+   will do nothing.
+
+
+/////////////////////////////////////////////////////////////////////////////
+
+
+3. Hardware version 1
+   ==================
+
+3.1 Registers
+    ~~~~~~~~~
+
+By echoing a hexadecimal value to a register it contents can be altered.
+
+For example:
+
+   echo -n 0x16 > reg_10
+
+* reg_10
+
+   bit   7   6   5   4   3   2   1   0
+         B   C   T   D   L   A   S   E
+
+         E: 1 = enable smart edges unconditionally
+         S: 1 = enable smart edges only when dragging
+         A: 1 = absolute mode (needs 4 byte packets, see reg_11)
+         L: 1 = enable drag lock (see reg_22)
+         D: 1 = disable dynamic resolution
+         T: 1 = disable tapping
+         C: 1 = enable corner tap
+         B: 1 = swap left and right button
+
+* reg_11
+
+   bit   7   6   5   4   3   2   1   0
+         1   0   0   H   V   1   F   P
+
+         P: 1 = enable parity checking for relative mode
+         F: 1 = enable native 4 byte packet mode
+         V: 1 = enable vertical scroll area
+         H: 1 = enable horizontal scroll area
+
+* reg_20
+
+         single finger width?
+
+* reg_21
+
+         scroll area width (small: 0x40 ... wide: 0xff)
+
+* reg_22
+
+         drag lock time out (short: 0x14 ... long: 0xfe;
+                             0xff = tap again to release)
+
+* reg_23
+
+         tap make timeout?
+
+* reg_24
+
+         tap release timeout?
+
+* reg_25
+
+         smart edge cursor speed (0x02 = slow, 0x03 = medium, 0x04 = fast)
+
+* reg_26
+
+         smart edge activation area width?
+
+
+3.2 Native relative mode 4 byte packet format
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+byte 0:
+   bit   7   6   5   4   3   2   1   0
+         c   c  p2  p1   1   M   R   L
+
+         L, R, M = 1 when Left, Right, Middle mouse button pressed
+            some models have M as byte 3 odd parity bit
+         when parity checking is enabled (reg_11, P = 1):
+            p1..p2 = byte 1 and 2 odd parity bit
+         c = 1 when corner tap detected
+
+byte 1:
+   bit   7   6   5   4   3   2   1   0
+        dx7 dx6 dx5 dx4 dx3 dx2 dx1 dx0
+
+         dx7..dx0 = x movement;   positive = right, negative = left
+         byte 1 = 0xf0 when corner tap detected
+
+byte 2:
+   bit   7   6   5   4   3   2   1   0
+        dy7 dy6 dy5 dy4 dy3 dy2 dy1 dy0
+
+         dy7..dy0 = y movement;   positive = up,    negative = down
+
+byte 3:
+   parity checking enabled (reg_11, P = 1):
+
+      bit   7   6   5   4   3   2   1   0
+            w   h  n1  n0  ds3 ds2 ds1 ds0
+
+            normally:
+               ds3..ds0 = scroll wheel amount and direction
+                          positive = down or left
+                          negative = up or right
+            when corner tap detected:
+               ds0 = 1 when top right corner tapped
+               ds1 = 1 when bottom right corner tapped
+               ds2 = 1 when bottom left corner tapped
+               ds3 = 1 when top left corner tapped
+            n1..n0 = number of fingers on touchpad
+               only models with firmware 2.x report this, models with
+               firmware 1.x seem to map one, two and three finger taps
+               directly to L, M and R mouse buttons
+            h = 1 when horizontal scroll action
+            w = 1 when wide finger touch?
+
+   otherwise (reg_11, P = 0):
+
+      bit   7   6   5   4   3   2   1   0
+           ds7 ds6 ds5 ds4 ds3 ds2 ds1 ds0
+
+            ds7..ds0 = vertical scroll amount and direction
+                       negative = up
+                       positive = down
+
+
+3.3 Native absolute mode 4 byte packet format
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+byte 0:
+   firmware version 1.x:
+
+      bit   7   6   5   4   3   2   1   0
+            D   U  p1  p2   1  p3   R   L
+
+            L, R = 1 when Left, Right mouse button pressed
+            p1..p3 = byte 1..3 odd parity bit
+            D, U = 1 when rocker switch pressed Up, Down
+
+   firmware version 2.x:
+
+      bit   7   6   5   4   3   2   1   0
+           n1  n0  p2  p1   1  p3   R   L
+
+            L, R = 1 when Left, Right mouse button pressed
+            p1..p3 = byte 1..3 odd parity bit
+            n1..n0 = number of fingers on touchpad
+
+byte 1:
+   firmware version 1.x:
+
+      bit   7   6   5   4   3   2   1   0
+            f   0  th  tw  x9  x8  y9  y8
+
+            tw = 1 when two finger touch
+            th = 1 when three finger touch
+            f  = 1 when finger touch
+
+   firmware version 2.x:
+
+      bit   7   6   5   4   3   2   1   0
+            .   .   .   .  x9  x8  y9  y8
+
+byte 2:
+   bit   7   6   5   4   3   2   1   0
+        x7  x6  x5  x4  x3  x2  x1  x0
+
+         x9..x0 = absolute x value (horizontal)
+
+byte 3:
+   bit   7   6   5   4   3   2   1   0
+        y7  y6  y5  y4  y3  y2  y1  y0
+
+         y9..y0 = absolute y value (vertical)
+
+
+/////////////////////////////////////////////////////////////////////////////
+
+
+4. Hardware version 2
+   ==================
+
+
+4.1 Registers
+    ~~~~~~~~~
+
+By echoing a hexadecimal value to a register it contents can be altered.
+
+For example:
+
+   echo -n 0x56 > reg_10
+
+* reg_10
+
+   bit   7   6   5   4   3   2   1   0
+         0   1   0   1   0   1   D   0
+
+         D: 1 = enable drag and drop
+
+* reg_11
+
+   bit   7   6   5   4   3   2   1   0
+         1   0   0   0   S   0   1   0
+
+         S: 1 = enable vertical scroll
+
+* reg_21
+
+         unknown (0x00)
+
+* reg_22
+
+         drag and drop release time out (short: 0x70 ... long 0x7e;
+                                   0x7f = never i.e. tap again to release)
+
+
+4.2 Native absolute mode 6 byte packet format
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+4.2.1 One finger touch
+      ~~~~~~~~~~~~~~~~
+
+byte 0:
+
+   bit   7   6   5   4   3   2   1   0
+        n1  n0   .   .   .   .   R   L
+
+         L, R = 1 when Left, Right mouse button pressed
+         n1..n0 = numbers of fingers on touchpad
+
+byte 1:
+
+   bit   7   6   5   4   3   2   1   0
+        x15 x14 x13 x12 x11 x10 x9  x8
+
+byte 2:
+
+   bit   7   6   5   4   3   2   1   0
+        x7  x6  x5  x4  x4  x2  x1  x0
+
+         x15..x0 = absolute x value (horizontal)
+
+byte 3:
+
+   bit   7   6   5   4   3   2   1   0
+         .   .   .   .   .   .   .   .
+
+byte 4:
+
+   bit   7   6   5   4   3   2   1   0
+        y15 y14 y13 y12 y11 y10 y8  y8
+
+byte 5:
+
+   bit   7   6   5   4   3   2   1   0
+        y7  y6  y5  y4  y3  y2  y1  y0
+
+         y15..y0 = absolute y value (vertical)
+
+
+4.2.2 Two finger touch
+      ~~~~~~~~~~~~~~~~
+
+byte 0:
+
+   bit   7   6   5   4   3   2   1   0
+        n1  n0  ay8 ax8  .   .   R   L
+
+         L, R = 1 when Left, Right mouse button pressed
+         n1..n0 = numbers of fingers on touchpad
+
+byte 1:
+
+   bit   7   6   5   4   3   2   1   0
+        ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
+
+         ax8..ax0 = first finger absolute x value
+
+byte 2:
+
+   bit   7   6   5   4   3   2   1   0
+        ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0
+
+         ay8..ay0 = first finger absolute y value
+
+byte 3:
+
+   bit   7   6   5   4   3   2   1   0
+         .   .  by8 bx8  .   .   .   .
+
+byte 4:
+
+   bit   7   6   5   4   3   2   1   0
+        bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
+
+         bx8..bx0 = second finger absolute x value
+
+byte 5:
+
+   bit   7   6   5   4   3   2   1   0
+        by7 by8 by5 by4 by3 by2 by1 by0
+
+         by8..by0 = second finger absolute y value
@@ -25,8 +25,8 @@
 	  mice with wheels and extra buttons, Microsoft, Logitech or Genius
 	  compatible.
  
-	  Synaptics TouchPad users might be interested in a specialized
-	  XFree86 driver at:
+	  Synaptics, ALPS or Elantech TouchPad users might be interested
+	  in a specialized Xorg/XFree86 driver at:
 		<http://w1.894.telia.com/~u89404340/touchpad/index.html>
 	  and a new version of GPM at:
 		<http://www.geocities.com/dt_or/gpm/gpm.html>
@@ -86,6 +86,27 @@
 	  to your system.
  
 	  If unsure, say Y.
+
+config MOUSE_PS2_ELANTECH
+	bool "Elantech PS/2 protocol extension"
+	depends on MOUSE_PS2
+	help
+	  Say Y here if you have an Elantech PS/2 touchpad connected
+	  to your system.
+
+	  Note that if you enable this driver you will need an updated
+	  X.org Synaptics driver that does not require ABS_PRESSURE
+	  reports from the touchpad (i.e. post 1.5.0 version). You can
+	  grab a patch for the driver here:
+
+	  http://userweb.kernel.org/~dtor/synaptics-no-abspressure.patch
+
+	  If unsure, say N.
+
+	  This driver exposes some configuration registers via sysfs
+	  entries. For further information,
+	  see <file:Documentation/input/elantech.txt>.
+
  
 config MOUSE_PS2_TOUCHKIT
 	bool "eGalax TouchKit PS/2 protocol extension"
@@ -21,6 +21,7 @@
 psmouse-objs := psmouse-base.o synaptics.o
  
 psmouse-$(CONFIG_MOUSE_PS2_ALPS)	+= alps.o
+psmouse-$(CONFIG_MOUSE_PS2_ELANTECH)	+= elantech.o
 psmouse-$(CONFIG_MOUSE_PS2_OLPC)	+= hgpk.o
 psmouse-$(CONFIG_MOUSE_PS2_LOGIPS2PP)	+= logips2pp.o
 psmouse-$(CONFIG_MOUSE_PS2_LIFEBOOK)	+= lifebook.o
+/*
+ * Elantech Touchpad driver (v5)
+ *
+ * Copyright (C) 2007-2008 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/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)
+
+/*
+ * 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;
+
+	if (etd->fw_version_maj == 0x01) {
+		/* 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;
+	}
+
+	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_maj == 0x01) &&
+	    (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);
+}
+
+/*
+ * 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: x15 x14 x13 x12 x11 x10 x9  x8
+		   byte 2: x7  x6  x5  x4  x4  x2  x1  x0 */
+		input_report_abs(dev, ABS_X, (packet[1] << 8) | packet[2]);
+		/* byte 4: y15 y14 y13 y12 y11 y10 y8  y8
+		   byte 5: y7  y6  y5  y4  y3  y2  y1  y0 */
+		input_report_abs(dev, ABS_Y, ETP_YMAX_V2 -
+			((packet[4] << 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_maj == 0x01) {
+		/* 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;
+		}
+		/*
+		 * Read back reg 0x10. 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");
+		break;
+	}
+
+	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);
+
+	__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_maj == 0x01) &&
+		    (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, int 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_err("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_info("elantech.c: unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
+			param[0], param[1], param[2]);
+		return -1;
+	}
+
+	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];
+
+	etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
+	psmouse->private = etd;
+	if (!etd)
+		return -1;
+
+	etd->parity[0] = 1;
+	for (i = 1; i < 256; i++)
+		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
+
+	/*
+	 * Find out what version hardware this is
+	 */
+	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
+		pr_err("elantech.c: failed to query firmware version.\n");
+		goto init_fail;
+	}
+	pr_info("elantech.c: Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
+		param[0], param[1], param[2]);
+	etd->fw_version_maj = param[0];
+	etd->fw_version_min = param[2];
+
+	/*
+	 * Assume every version greater than this is new EeePC style
+	 * hardware with 6 byte packets
+	 */
+	if (etd->fw_version_maj >= 0x02 && etd->fw_version_min >= 0x30) {
+		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\n",
+		etd->hw_version, etd->fw_version_maj, etd->fw_version_min);
+
+	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];
+
+	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 (v5)
+ *
+ * Copyright (C) 2007-2008 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.
+ */
+
+#ifndef _ELANTECH_H
+#define _ELANTECH_H
+
+/*
+ * Command values for Synaptics style queries
+ */
+#define ETP_FW_VERSION_QUERY		0x01
+#define ETP_CAPABILITIES_QUERY		0x02
+
+/*
+ * Command values for register reading or writing
+ */
+#define ETP_REGISTER_READ		0x10
+#define ETP_REGISTER_WRITE		0x11
+
+/*
+ * Hardware version 2 custom PS/2 command value
+ */
+#define ETP_PS2_CUSTOM_COMMAND		0xf8
+
+/*
+ * Times to retry a ps2_command and millisecond delay between tries
+ */
+#define ETP_PS2_COMMAND_TRIES		3
+#define ETP_PS2_COMMAND_DELAY		500
+
+/*
+ * Times to try to read back a register and millisecond delay between tries
+ */
+#define ETP_READ_BACK_TRIES		5
+#define ETP_READ_BACK_DELAY		2000
+
+/*
+ * Register bitmasks for hardware version 1
+ */
+#define ETP_R10_ABSOLUTE_MODE		0x04
+#define ETP_R11_4_BYTE_MODE		0x02
+
+/*
+ * Capability bitmasks
+ */
+#define ETP_CAP_HAS_ROCKER		0x04
+
+/*
+ * One hard to find application note states that X axis range is 0 to 576
+ * and Y axis range is 0 to 384 for harware version 1.
+ * Edge fuzz might be necessary because of bezel around the touchpad
+ */
+#define ETP_EDGE_FUZZ_V1		32
+
+#define ETP_XMIN_V1			(  0 + ETP_EDGE_FUZZ_V1)
+#define ETP_XMAX_V1			(576 - ETP_EDGE_FUZZ_V1)
+#define ETP_YMIN_V1			(  0 + ETP_EDGE_FUZZ_V1)
+#define ETP_YMAX_V1			(384 - ETP_EDGE_FUZZ_V1)
+
+/*
+ * It seems the resolution for hardware version 2 doubled.
+ * Hence the X and Y ranges are doubled too.
+ * The bezel around the pad also appears to be smaller
+ */
+#define ETP_EDGE_FUZZ_V2		8
+
+#define ETP_XMIN_V2			(   0 + ETP_EDGE_FUZZ_V2)
+#define ETP_XMAX_V2			(1152 - ETP_EDGE_FUZZ_V2)
+#define ETP_YMIN_V2			(   0 + ETP_EDGE_FUZZ_V2)
+#define ETP_YMAX_V2			( 768 - ETP_EDGE_FUZZ_V2)
+
+/*
+ * For two finger touches the coordinate of each finger gets reported
+ * separately but with reduced resolution.
+ */
+#define ETP_2FT_FUZZ			4
+
+#define ETP_2FT_XMIN			(  0 + ETP_2FT_FUZZ)
+#define ETP_2FT_XMAX			(288 - ETP_2FT_FUZZ)
+#define ETP_2FT_YMIN			(  0 + ETP_2FT_FUZZ)
+#define ETP_2FT_YMAX			(192 - ETP_2FT_FUZZ)
+
+struct elantech_data {
+	unsigned char reg_10;
+	unsigned char reg_11;
+	unsigned char reg_20;
+	unsigned char reg_21;
+	unsigned char reg_22;
+	unsigned char reg_23;
+	unsigned char reg_24;
+	unsigned char reg_25;
+	unsigned char reg_26;
+	unsigned char debug;
+	unsigned char capabilities;
+	unsigned char fw_version_maj;
+	unsigned char fw_version_min;
+	unsigned char hw_version;
+	unsigned char paritycheck;
+	unsigned char parity[256];
+};
+
+#ifdef CONFIG_MOUSE_PS2_ELANTECH
+int elantech_detect(struct psmouse *psmouse, int set_properties);
+int elantech_init(struct psmouse *psmouse);
+#else
+static inline int elantech_detect(struct psmouse *psmouse, int set_properties)
+{
+	return -ENOSYS;
+}
+static inline int elantech_init(struct psmouse *psmouse)
+{
+	return -ENOSYS;
+}
+#endif /* CONFIG_MOUSE_PS2_ELANTECH */
+
+#endif
@@ -29,6 +29,7 @@
 #include "lifebook.h"
 #include "trackpoint.h"
 #include "touchkit_ps2.h"
+#include "elantech.h"
  
 #define DRIVER_DESC	"PS/2 mouse driver"
  
@@ -650,6 +651,19 @@
 		max_proto = PSMOUSE_IMEX;
 	}
  
+/*
+ * Try Elantech touchpad.
+ */
+	if (max_proto > PSMOUSE_IMEX &&
+			elantech_detect(psmouse, set_properties) == 0) {
+		if (!set_properties || elantech_init(psmouse) == 0)
+			return PSMOUSE_ELANTECH;
+/*
+ * Init failed, try basic relative protocols
+ */
+		max_proto = PSMOUSE_IMEX;
+	}
+
 	if (max_proto > PSMOUSE_IMEX) {
 		if (genius_detect(psmouse, set_properties) == 0)
 			return PSMOUSE_GENPS;
@@ -789,6 +803,15 @@
 		.detect		= hgpk_detect,
 	},
 #endif
+#ifdef CONFIG_MOUSE_PS2_ELANTECH
+	{
+		.type		= PSMOUSE_ELANTECH,
+		.name		= "ETPS/2",
+		.alias		= "elantech",
+		.detect		= elantech_detect,
+		.init		= elantech_init,
+	},
+ #endif
 	{
 		.type		= PSMOUSE_CORTRON,
 		.name		= "CortronPS/2",
@@ -90,6 +90,7 @@
 	PSMOUSE_TOUCHKIT_PS2,
 	PSMOUSE_CORTRON,
 	PSMOUSE_HGPK,
+	PSMOUSE_ELANTECH,
 	PSMOUSE_AUTO		/* This one should always be last */
 };
	1	+Elantech Touchpad Driver
	2	+========================
	3	+
	4	+ Copyright (C) 2007-2008 Arjan Opmeer <arjan@opmeer.net>
	5	+
	6	+ Extra information for hardware version 1 found and
	7	+ provided by Steve Havelka
	8	+
	9	+ Version 2 (EeePC) hardware support based on patches
	10	+ received from Woody at Xandros and forwarded to me
	11	+ by user StewieGriffin at the eeeuser.com forum
	12	+
	13	+
	14	+Contents
	15	+~~~~~~~~
	16	+
	17	+ 1. Introduction
	18	+ 2. Extra knobs
	19	+ 3. Hardware version 1
	20	+ 3.1 Registers
	21	+ 3.2 Native relative mode 4 byte packet format
	22	+ 3.3 Native absolute mode 4 byte packet format
	23	+ 4. Hardware version 2
	24	+ 4.1 Registers
	25	+ 4.2 Native absolute mode 6 byte packet format
	26	+ 4.2.1 One finger touch
	27	+ 4.2.2 Two finger touch
	28	+
	29	+
	30	+
	31	+1. Introduction
	32	+ ~~~~~~~~~~~~
	33	+
	34	+Currently the Linux Elantech touchpad driver is aware of two different
	35	+hardware versions unimaginatively called version 1 and version 2. Version 1
	36	+is found in "older" laptops and uses 4 bytes per packet. Version 2 seems to
	37	+be introduced with the EeePC and uses 6 bytes per packet.
	38	+
	39	+The driver tries to support both hardware versions and should be compatible
	40	+with the Xorg Synaptics touchpad driver and its graphical configuration
	41	+utilities.
	42	+
	43	+Additionally the operation of the touchpad can be altered by adjusting the
	44	+contents of some of its internal registers. These registers are represented
	45	+by the driver as sysfs entries under /sys/bus/serio/drivers/psmouse/serio?
	46	+that can be read from and written to.
	47	+
	48	+Currently only the registers for hardware version 1 are somewhat understood.
	49	+Hardware version 2 seems to use some of the same registers but it is not
	50	+known whether the bits in the registers represent the same thing or might
	51	+have changed their meaning.
	52	+
	53	+On top of that, some register settings have effect only when the touchpad is
	54	+in relative mode and not in absolute mode. As the Linux Elantech touchpad
	55	+driver always puts the hardware into absolute mode not all information
	56	+mentioned below can be used immediately. But because there is no freely
	57	+available Elantech documentation the information is provided here anyway for
	58	+completeness sake.
	59	+
	60	+
	61	+/////////////////////////////////////////////////////////////////////////////
	62	+
	63	+
	64	+2. Extra knobs
	65	+ ~~~~~~~~~~~
	66	+
	67	+Currently the Linux Elantech touchpad driver provides two extra knobs under
	68	+/sys/bus/serio/drivers/psmouse/serio? for the user.
	69	+
	70	+* debug
	71	+
	72	+ Turn different levels of debugging ON or OFF.
	73	+
	74	+ By echoing "0" to this file all debugging will be turned OFF.
	75	+
	76	+ Currently a value of "1" will turn on some basic debugging and a value of
	77	+ "2" will turn on packet debugging. For hardware version 1 the default is
	78	+ OFF. For version 2 the default is "1".
	79	+
	80	+ Turning packet debugging on will make the driver dump every packet
	81	+ received to the syslog before processing it. Be warned that this can
	82	+ generate quite a lot of data!
	83	+
	84	+* paritycheck
	85	+
	86	+ Turns parity checking ON or OFF.
	87	+
	88	+ By echoing "0" to this file parity checking will be turned OFF. Any
	89	+ non-zero value will turn it ON. For hardware version 1 the default is ON.
	90	+ For version 2 the default it is OFF.
	91	+
	92	+ Hardware version 1 provides basic data integrity verification by
	93	+ calculating a parity bit for the last 3 bytes of each packet. The driver
	94	+ can check these bits and reject any packet that appears corrupted. Using
	95	+ this knob you can bypass that check.
	96	+
	97	+ It is not known yet whether hardware version 2 provides the same parity
	98	+ bits. Hence checking is disabled by default. Currently even turning it on
	99	+ will do nothing.
	100	+
	101	+
	102	+/////////////////////////////////////////////////////////////////////////////
	103	+
	104	+
	105	+3. Hardware version 1
	106	+ ==================
	107	+
	108	+3.1 Registers
	109	+ ~~~~~~~~~
	110	+
	111	+By echoing a hexadecimal value to a register it contents can be altered.
	112	+
	113	+For example:
	114	+
	115	+ echo -n 0x16 > reg_10
	116	+
	117	+* reg_10
	118	+
	119	+ bit 7 6 5 4 3 2 1 0
	120	+ B C T D L A S E
	121	+
	122	+ E: 1 = enable smart edges unconditionally
	123	+ S: 1 = enable smart edges only when dragging
	124	+ A: 1 = absolute mode (needs 4 byte packets, see reg_11)
	125	+ L: 1 = enable drag lock (see reg_22)
	126	+ D: 1 = disable dynamic resolution
	127	+ T: 1 = disable tapping
	128	+ C: 1 = enable corner tap
	129	+ B: 1 = swap left and right button
	130	+
	131	+* reg_11
	132	+
	133	+ bit 7 6 5 4 3 2 1 0
	134	+ 1 0 0 H V 1 F P
	135	+
	136	+ P: 1 = enable parity checking for relative mode
	137	+ F: 1 = enable native 4 byte packet mode
	138	+ V: 1 = enable vertical scroll area
	139	+ H: 1 = enable horizontal scroll area
	140	+
	141	+* reg_20
	142	+
	143	+ single finger width?
	144	+
	145	+* reg_21
	146	+
	147	+ scroll area width (small: 0x40 ... wide: 0xff)
	148	+
	149	+* reg_22
	150	+
	151	+ drag lock time out (short: 0x14 ... long: 0xfe;
	152	+ 0xff = tap again to release)
	153	+
	154	+* reg_23
	155	+
	156	+ tap make timeout?
	157	+
	158	+* reg_24
	159	+
	160	+ tap release timeout?
	161	+
	162	+* reg_25
	163	+
	164	+ smart edge cursor speed (0x02 = slow, 0x03 = medium, 0x04 = fast)
	165	+
	166	+* reg_26
	167	+
	168	+ smart edge activation area width?
	169	+
	170	+
	171	+3.2 Native relative mode 4 byte packet format
	172	+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	173	+
	174	+byte 0:
	175	+ bit 7 6 5 4 3 2 1 0
	176	+ c c p2 p1 1 M R L
	177	+
	178	+ L, R, M = 1 when Left, Right, Middle mouse button pressed
	179	+ some models have M as byte 3 odd parity bit
	180	+ when parity checking is enabled (reg_11, P = 1):
	181	+ p1..p2 = byte 1 and 2 odd parity bit
	182	+ c = 1 when corner tap detected
	183	+
	184	+byte 1:
	185	+ bit 7 6 5 4 3 2 1 0
	186	+ dx7 dx6 dx5 dx4 dx3 dx2 dx1 dx0
	187	+
	188	+ dx7..dx0 = x movement; positive = right, negative = left
	189	+ byte 1 = 0xf0 when corner tap detected
	190	+
	191	+byte 2:
	192	+ bit 7 6 5 4 3 2 1 0
	193	+ dy7 dy6 dy5 dy4 dy3 dy2 dy1 dy0
	194	+
	195	+ dy7..dy0 = y movement; positive = up, negative = down
	196	+
	197	+byte 3:
	198	+ parity checking enabled (reg_11, P = 1):
	199	+
	200	+ bit 7 6 5 4 3 2 1 0
	201	+ w h n1 n0 ds3 ds2 ds1 ds0
	202	+
	203	+ normally:
	204	+ ds3..ds0 = scroll wheel amount and direction
	205	+ positive = down or left
	206	+ negative = up or right
	207	+ when corner tap detected:
	208	+ ds0 = 1 when top right corner tapped
	209	+ ds1 = 1 when bottom right corner tapped
	210	+ ds2 = 1 when bottom left corner tapped
	211	+ ds3 = 1 when top left corner tapped
	212	+ n1..n0 = number of fingers on touchpad
	213	+ only models with firmware 2.x report this, models with
	214	+ firmware 1.x seem to map one, two and three finger taps
	215	+ directly to L, M and R mouse buttons
	216	+ h = 1 when horizontal scroll action
	217	+ w = 1 when wide finger touch?
	218	+
	219	+ otherwise (reg_11, P = 0):
	220	+
	221	+ bit 7 6 5 4 3 2 1 0
	222	+ ds7 ds6 ds5 ds4 ds3 ds2 ds1 ds0
	223	+
	224	+ ds7..ds0 = vertical scroll amount and direction
	225	+ negative = up
	226	+ positive = down
	227	+
	228	+
	229	+3.3 Native absolute mode 4 byte packet format
	230	+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	231	+
	232	+byte 0:
	233	+ firmware version 1.x:
	234	+
	235	+ bit 7 6 5 4 3 2 1 0
	236	+ D U p1 p2 1 p3 R L
	237	+
	238	+ L, R = 1 when Left, Right mouse button pressed
	239	+ p1..p3 = byte 1..3 odd parity bit
	240	+ D, U = 1 when rocker switch pressed Up, Down
	241	+
	242	+ firmware version 2.x:
	243	+
	244	+ bit 7 6 5 4 3 2 1 0
	245	+ n1 n0 p2 p1 1 p3 R L
	246	+
	247	+ L, R = 1 when Left, Right mouse button pressed
	248	+ p1..p3 = byte 1..3 odd parity bit
	249	+ n1..n0 = number of fingers on touchpad
	250	+
	251	+byte 1:
	252	+ firmware version 1.x:
	253	+
	254	+ bit 7 6 5 4 3 2 1 0
	255	+ f 0 th tw x9 x8 y9 y8
	256	+
	257	+ tw = 1 when two finger touch
	258	+ th = 1 when three finger touch
	259	+ f = 1 when finger touch
	260	+
	261	+ firmware version 2.x:
	262	+
	263	+ bit 7 6 5 4 3 2 1 0
	264	+ . . . . x9 x8 y9 y8
	265	+
	266	+byte 2:
	267	+ bit 7 6 5 4 3 2 1 0
	268	+ x7 x6 x5 x4 x3 x2 x1 x0
	269	+
	270	+ x9..x0 = absolute x value (horizontal)
	271	+
	272	+byte 3:
	273	+ bit 7 6 5 4 3 2 1 0
	274	+ y7 y6 y5 y4 y3 y2 y1 y0
	275	+
	276	+ y9..y0 = absolute y value (vertical)
	277	+
	278	+
	279	+/////////////////////////////////////////////////////////////////////////////
	280	+
	281	+
	282	+4. Hardware version 2
	283	+ ==================
	284	+
	285	+
	286	+4.1 Registers
	287	+ ~~~~~~~~~
	288	+
	289	+By echoing a hexadecimal value to a register it contents can be altered.
	290	+
	291	+For example:
	292	+
	293	+ echo -n 0x56 > reg_10
	294	+
	295	+* reg_10
	296	+
	297	+ bit 7 6 5 4 3 2 1 0
	298	+ 0 1 0 1 0 1 D 0
	299	+
	300	+ D: 1 = enable drag and drop
	301	+
	302	+* reg_11
	303	+
	304	+ bit 7 6 5 4 3 2 1 0
	305	+ 1 0 0 0 S 0 1 0
	306	+
	307	+ S: 1 = enable vertical scroll
	308	+
	309	+* reg_21
	310	+
	311	+ unknown (0x00)
	312	+
	313	+* reg_22
	314	+
	315	+ drag and drop release time out (short: 0x70 ... long 0x7e;
	316	+ 0x7f = never i.e. tap again to release)
	317	+
	318	+
	319	+4.2 Native absolute mode 6 byte packet format
	320	+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	321	+
	322	+4.2.1 One finger touch
	323	+ ~~~~~~~~~~~~~~~~
	324	+
	325	+byte 0:
	326	+
	327	+ bit 7 6 5 4 3 2 1 0
	328	+ n1 n0 . . . . R L
	329	+
	330	+ L, R = 1 when Left, Right mouse button pressed
	331	+ n1..n0 = numbers of fingers on touchpad
	332	+
	333	+byte 1:
	334	+
	335	+ bit 7 6 5 4 3 2 1 0
	336	+ x15 x14 x13 x12 x11 x10 x9 x8
	337	+
	338	+byte 2:
	339	+
	340	+ bit 7 6 5 4 3 2 1 0
	341	+ x7 x6 x5 x4 x4 x2 x1 x0
	342	+
	343	+ x15..x0 = absolute x value (horizontal)
	344	+
	345	+byte 3:
	346	+
	347	+ bit 7 6 5 4 3 2 1 0
	348	+ . . . . . . . .
	349	+
	350	+byte 4:
	351	+
	352	+ bit 7 6 5 4 3 2 1 0
	353	+ y15 y14 y13 y12 y11 y10 y8 y8
	354	+
	355	+byte 5:
	356	+
	357	+ bit 7 6 5 4 3 2 1 0
	358	+ y7 y6 y5 y4 y3 y2 y1 y0
	359	+
	360	+ y15..y0 = absolute y value (vertical)
	361	+
	362	+
	363	+4.2.2 Two finger touch
	364	+ ~~~~~~~~~~~~~~~~
	365	+
	366	+byte 0:
	367	+
	368	+ bit 7 6 5 4 3 2 1 0
	369	+ n1 n0 ay8 ax8 . . R L
	370	+
	371	+ L, R = 1 when Left, Right mouse button pressed
	372	+ n1..n0 = numbers of fingers on touchpad
	373	+
	374	+byte 1:
	375	+
	376	+ bit 7 6 5 4 3 2 1 0
	377	+ ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
	378	+
	379	+ ax8..ax0 = first finger absolute x value
	380	+
	381	+byte 2:
	382	+
	383	+ bit 7 6 5 4 3 2 1 0
	384	+ ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0
	385	+
	386	+ ay8..ay0 = first finger absolute y value
	387	+
	388	+byte 3:
	389	+
	390	+ bit 7 6 5 4 3 2 1 0
	391	+ . . by8 bx8 . . . .
	392	+
	393	+byte 4:
	394	+
	395	+ bit 7 6 5 4 3 2 1 0
	396	+ bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
	397	+
	398	+ bx8..bx0 = second finger absolute x value
	399	+
	400	+byte 5:
	401	+
	402	+ bit 7 6 5 4 3 2 1 0
	403	+ by7 by8 by5 by4 by3 by2 by1 by0
	404	+
	405	+ by8..by0 = second finger absolute y value
...	...	@@ -25,8 +25,8 @@
25	25	mice with wheels and extra buttons, Microsoft, Logitech or Genius
26	26	compatible.
27	27
28		- Synaptics TouchPad users might be interested in a specialized
29		- XFree86 driver at:
	28	+ Synaptics, ALPS or Elantech TouchPad users might be interested
	29	+ in a specialized Xorg/XFree86 driver at:
30	30	<http://w1.894.telia.com/~u89404340/touchpad/index.html>
31	31	and a new version of GPM at:
32	32	<http://www.geocities.com/dt_or/gpm/gpm.html>
...	...	@@ -86,6 +86,27 @@
86	86	to your system.
87	87
88	88	If unsure, say Y.
	89	+
	90	+config MOUSE_PS2_ELANTECH
	91	+ bool "Elantech PS/2 protocol extension"
	92	+ depends on MOUSE_PS2
	93	+ help
	94	+ Say Y here if you have an Elantech PS/2 touchpad connected
	95	+ to your system.
	96	+
	97	+ Note that if you enable this driver you will need an updated
	98	+ X.org Synaptics driver that does not require ABS_PRESSURE
	99	+ reports from the touchpad (i.e. post 1.5.0 version). You can
	100	+ grab a patch for the driver here:
	101	+
	102	+ http://userweb.kernel.org/~dtor/synaptics-no-abspressure.patch
	103	+
	104	+ If unsure, say N.
	105	+
	106	+ This driver exposes some configuration registers via sysfs
	107	+ entries. For further information,
	108	+ see <file:Documentation/input/elantech.txt>.
	109	+
89	110
90	111	config MOUSE_PS2_TOUCHKIT
91	112	bool "eGalax TouchKit PS/2 protocol extension"
...	...	@@ -21,6 +21,7 @@
21	21	psmouse-objs := psmouse-base.o synaptics.o
22	22
23	23	psmouse-$(CONFIG_MOUSE_PS2_ALPS) += alps.o
	24	+psmouse-$(CONFIG_MOUSE_PS2_ELANTECH) += elantech.o
24	25	psmouse-$(CONFIG_MOUSE_PS2_OLPC) += hgpk.o
25	26	psmouse-$(CONFIG_MOUSE_PS2_LOGIPS2PP) += logips2pp.o
26	27	psmouse-$(CONFIG_MOUSE_PS2_LIFEBOOK) += lifebook.o
	1	+/*
	2	+ * Elantech Touchpad driver (v5)
	3	+ *
	4	+ * Copyright (C) 2007-2008 Arjan Opmeer <arjan@opmeer.net>
	5	+ *
	6	+ * This program is free software; you can redistribute it and/or modify it
	7	+ * under the terms of the GNU General Public License version 2 as published
	8	+ * by the Free Software Foundation.
	9	+ *
	10	+ * Trademarks are the property of their respective owners.
	11	+ */
	12	+
	13	+#include <linux/delay.h>
	14	+#include <linux/module.h>
	15	+#include <linux/input.h>
	16	+#include <linux/serio.h>
	17	+#include <linux/libps2.h>
	18	+#include "psmouse.h"
	19	+#include "elantech.h"
	20	+
	21	+#define elantech_debug(format, arg...) \
	22	+ do { \
	23	+ if (etd->debug) \
	24	+ printk(KERN_DEBUG format, ##arg); \
	25	+ } while (0)
	26	+
	27	+/*
	28	+ * Send a Synaptics style sliced query command
	29	+ */
	30	+static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
	31	+ unsigned char *param)
	32	+{
	33	+ if (psmouse_sliced_command(psmouse, c) \|\|
	34	+ ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
	35	+ pr_err("elantech.c: synaptics_send_cmd query 0x%02x failed.\n", c);
	36	+ return -1;
	37	+ }
	38	+
	39	+ return 0;
	40	+}
	41	+
	42	+/*
	43	+ * A retrying version of ps2_command
	44	+ */
	45	+static int elantech_ps2_command(struct psmouse *psmouse,
	46	+ unsigned char *param, int command)
	47	+{
	48	+ struct ps2dev *ps2dev = &psmouse->ps2dev;
	49	+ struct elantech_data *etd = psmouse->private;
	50	+ int rc;
	51	+ int tries = ETP_PS2_COMMAND_TRIES;
	52	+
	53	+ do {
	54	+ rc = ps2_command(ps2dev, param, command);
	55	+ if (rc == 0)
	56	+ break;
	57	+ tries--;
	58	+ elantech_debug("elantech.c: retrying ps2 command 0x%02x (%d).\n",
	59	+ command, tries);
	60	+ msleep(ETP_PS2_COMMAND_DELAY);
	61	+ } while (tries > 0);
	62	+
	63	+ if (rc)
	64	+ pr_err("elantech.c: ps2 command 0x%02x failed.\n", command);
	65	+
	66	+ return rc;
	67	+}
	68	+
	69	+/*
	70	+ * Send an Elantech style special command to read a value from a register
	71	+ */
	72	+static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
	73	+ unsigned char *val)
	74	+{
	75	+ struct elantech_data *etd = psmouse->private;
	76	+ unsigned char param[3];
	77	+ int rc = 0;
	78	+
	79	+ if (reg < 0x10 \|\| reg > 0x26)
	80	+ return -1;
	81	+
	82	+ if (reg > 0x11 && reg < 0x20)
	83	+ return -1;
	84	+
	85	+ switch (etd->hw_version) {
	86	+ case 1:
	87	+ if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) \|\|
	88	+ psmouse_sliced_command(psmouse, reg) \|\|
	89	+ ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
	90	+ rc = -1;
	91	+ }
	92	+ break;
	93	+
	94	+ case 2:
	95	+ if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) \|\|
	96	+ elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READ) \|\|
	97	+ elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) \|\|
	98	+ elantech_ps2_command(psmouse, NULL, reg) \|\|
	99	+ elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
	100	+ rc = -1;
	101	+ }
	102	+ break;
	103	+ }
	104	+
	105	+ if (rc)
	106	+ pr_err("elantech.c: failed to read register 0x%02x.\n", reg);
	107	+ else
	108	+ *val = param[0];
	109	+
	110	+ return rc;
	111	+}
	112	+
	113	+/*
	114	+ * Send an Elantech style special command to write a register with a value
	115	+ */
	116	+static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
	117	+ unsigned char val)
	118	+{
	119	+ struct elantech_data *etd = psmouse->private;
	120	+ int rc = 0;
	121	+
	122	+ if (reg < 0x10 \|\| reg > 0x26)
	123	+ return -1;
	124	+
	125	+ if (reg > 0x11 && reg < 0x20)
	126	+ return -1;
	127	+
	128	+ switch (etd->hw_version) {
	129	+ case 1:
	130	+ if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) \|\|
	131	+ psmouse_sliced_command(psmouse, reg) \|\|
	132	+ psmouse_sliced_command(psmouse, val) \|\|
	133	+ ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
	134	+ rc = -1;
	135	+ }
	136	+ break;
	137	+
	138	+ case 2:
	139	+ if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) \|\|
	140	+ elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) \|\|
	141	+ elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) \|\|
	142	+ elantech_ps2_command(psmouse, NULL, reg) \|\|
	143	+ elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) \|\|
	144	+ elantech_ps2_command(psmouse, NULL, val) \|\|
	145	+ elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
	146	+ rc = -1;
	147	+ }
	148	+ break;
	149	+ }
	150	+
	151	+ if (rc)
	152	+ pr_err("elantech.c: failed to write register 0x%02x with value 0x%02x.\n",
	153	+ reg, val);
	154	+
	155	+ return rc;
	156	+}
	157	+
	158	+/*
	159	+ * Dump a complete mouse movement packet to the syslog
	160	+ */
	161	+static void elantech_packet_dump(unsigned char *packet, int size)
	162	+{
	163	+ int i;
	164	+
	165	+ printk(KERN_DEBUG "elantech.c: PS/2 packet [");
	166	+ for (i = 0; i < size; i++)
	167	+ printk("%s0x%02x ", (i) ? ", " : " ", packet[i]);
	168	+ printk("]\n");
	169	+}
	170	+
	171	+/*
	172	+ * Interpret complete data packets and report absolute mode input events for
	173	+ * hardware version 1. (4 byte packets)
	174	+ */
	175	+static void elantech_report_absolute_v1(struct psmouse *psmouse)
	176	+{
	177	+ struct input_dev *dev = psmouse->dev;
	178	+ struct elantech_data *etd = psmouse->private;
	179	+ unsigned char *packet = psmouse->packet;
	180	+ int fingers;
	181	+
	182	+ if (etd->fw_version_maj == 0x01) {
	183	+ /* byte 0: D U p1 p2 1 p3 R L
	184	+ byte 1: f 0 th tw x9 x8 y9 y8 */
	185	+ fingers = ((packet[1] & 0x80) >> 7) +
	186	+ ((packet[1] & 0x30) >> 4);
	187	+ } else {
	188	+ /* byte 0: n1 n0 p2 p1 1 p3 R L
	189	+ byte 1: 0 0 0 0 x9 x8 y9 y8 */
	190	+ fingers = (packet[0] & 0xc0) >> 6;
	191	+ }
	192	+
	193	+ input_report_key(dev, BTN_TOUCH, fingers != 0);
	194	+
	195	+ /* byte 2: x7 x6 x5 x4 x3 x2 x1 x0
	196	+ byte 3: y7 y6 y5 y4 y3 y2 y1 y0 */
	197	+ if (fingers) {
	198	+ input_report_abs(dev, ABS_X,
	199	+ ((packet[1] & 0x0c) << 6) \| packet[2]);
	200	+ input_report_abs(dev, ABS_Y, ETP_YMAX_V1 -
	201	+ (((packet[1] & 0x03) << 8) \| packet[3]));
	202	+ }
	203	+
	204	+ input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
	205	+ input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
	206	+ input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
	207	+ input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
	208	+ input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
	209	+
	210	+ if ((etd->fw_version_maj == 0x01) &&
	211	+ (etd->capabilities & ETP_CAP_HAS_ROCKER)) {
	212	+ /* rocker up */
	213	+ input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
	214	+ /* rocker down */
	215	+ input_report_key(dev, BTN_BACK, packet[0] & 0x80);
	216	+ }
	217	+
	218	+ input_sync(dev);
	219	+}
	220	+
	221	+/*
	222	+ * Interpret complete data packets and report absolute mode input events for
	223	+ * hardware version 2. (6 byte packets)
	224	+ */
	225	+static void elantech_report_absolute_v2(struct psmouse *psmouse)
	226	+{
	227	+ struct input_dev *dev = psmouse->dev;
	228	+ unsigned char *packet = psmouse->packet;
	229	+ int fingers, x1, y1, x2, y2;
	230	+
	231	+ /* byte 0: n1 n0 . . . . R L */
	232	+ fingers = (packet[0] & 0xc0) >> 6;
	233	+ input_report_key(dev, BTN_TOUCH, fingers != 0);
	234	+
	235	+ switch (fingers) {
	236	+ case 1:
	237	+ /* byte 1: x15 x14 x13 x12 x11 x10 x9 x8
	238	+ byte 2: x7 x6 x5 x4 x4 x2 x1 x0 */
	239	+ input_report_abs(dev, ABS_X, (packet[1] << 8) \| packet[2]);
	240	+ /* byte 4: y15 y14 y13 y12 y11 y10 y8 y8
	241	+ byte 5: y7 y6 y5 y4 y3 y2 y1 y0 */
	242	+ input_report_abs(dev, ABS_Y, ETP_YMAX_V2 -
	243	+ ((packet[4] << 8) \| packet[5]));
	244	+ break;
	245	+
	246	+ case 2:
	247	+ /* The coordinate of each finger is reported separately with
	248	+ a lower resolution for two finger touches */
	249	+ /* byte 0: . . ay8 ax8 . . . .
	250	+ byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0 */
	251	+ x1 = ((packet[0] & 0x10) << 4) \| packet[1];
	252	+ /* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
	253	+ y1 = ETP_2FT_YMAX - (((packet[0] & 0x20) << 3) \| packet[2]);
	254	+ /* byte 3: . . by8 bx8 . . . .
	255	+ byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0 */
	256	+ x2 = ((packet[3] & 0x10) << 4) \| packet[4];
	257	+ /* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
	258	+ y2 = ETP_2FT_YMAX - (((packet[3] & 0x20) << 3) \| packet[5]);
	259	+ /* For compatibility with the X Synaptics driver scale up one
	260	+ coordinate and report as ordinary mouse movent */
	261	+ input_report_abs(dev, ABS_X, x1 << 2);
	262	+ input_report_abs(dev, ABS_Y, y1 << 2);
	263	+ /* For compatibility with the proprietary X Elantech driver
	264	+ report both coordinates as hat coordinates */
	265	+ input_report_abs(dev, ABS_HAT0X, x1);
	266	+ input_report_abs(dev, ABS_HAT0Y, y1);
	267	+ input_report_abs(dev, ABS_HAT1X, x2);
	268	+ input_report_abs(dev, ABS_HAT1Y, y2);
	269	+ break;
	270	+ }
	271	+
	272	+ input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
	273	+ input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
	274	+ input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
	275	+ input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
	276	+ input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
	277	+
	278	+ input_sync(dev);
	279	+}
	280	+
	281	+static int elantech_check_parity_v1(struct psmouse *psmouse)
	282	+{
	283	+ struct elantech_data *etd = psmouse->private;
	284	+ unsigned char *packet = psmouse->packet;
	285	+ unsigned char p1, p2, p3;
	286	+
	287	+ /* Parity bits are placed differently */
	288	+ if (etd->fw_version_maj == 0x01) {
	289	+ /* byte 0: D U p1 p2 1 p3 R L */
	290	+ p1 = (packet[0] & 0x20) >> 5;
	291	+ p2 = (packet[0] & 0x10) >> 4;
	292	+ } else {
	293	+ /* byte 0: n1 n0 p2 p1 1 p3 R L */
	294	+ p1 = (packet[0] & 0x10) >> 4;
	295	+ p2 = (packet[0] & 0x20) >> 5;
	296	+ }
	297	+
	298	+ p3 = (packet[0] & 0x04) >> 2;
	299	+
	300	+ return etd->parity[packet[1]] == p1 &&
	301	+ etd->parity[packet[2]] == p2 &&
	302	+ etd->parity[packet[3]] == p3;
	303	+}
	304	+
	305	+/*
	306	+ * Process byte stream from mouse and handle complete packets
	307	+ */
	308	+static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
	309	+{
	310	+ struct elantech_data *etd = psmouse->private;
	311	+
	312	+ if (psmouse->pktcnt < psmouse->pktsize)
	313	+ return PSMOUSE_GOOD_DATA;
	314	+
	315	+ if (etd->debug > 1)
	316	+ elantech_packet_dump(psmouse->packet, psmouse->pktsize);
	317	+
	318	+ switch (etd->hw_version) {
	319	+ case 1:
	320	+ if (etd->paritycheck && !elantech_check_parity_v1(psmouse))
	321	+ return PSMOUSE_BAD_DATA;
	322	+
	323	+ elantech_report_absolute_v1(psmouse);
	324	+ break;
	325	+
	326	+ case 2:
	327	+ /* We don't know how to check parity in protocol v2 */
	328	+ elantech_report_absolute_v2(psmouse);
	329	+ break;
	330	+ }
	331	+
	332	+ return PSMOUSE_FULL_PACKET;
	333	+}
	334	+
	335	+/*
	336	+ * Put the touchpad into absolute mode
	337	+ */
	338	+static int elantech_set_absolute_mode(struct psmouse *psmouse)
	339	+{
	340	+ struct elantech_data *etd = psmouse->private;
	341	+ unsigned char val;
	342	+ int tries = ETP_READ_BACK_TRIES;
	343	+ int rc = 0;
	344	+
	345	+ switch (etd->hw_version) {
	346	+ case 1:
	347	+ etd->reg_10 = 0x16;
	348	+ etd->reg_11 = 0x8f;
	349	+ if (elantech_write_reg(psmouse, 0x10, etd->reg_10) \|\|
	350	+ elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
	351	+ rc = -1;
	352	+ }
	353	+ break;
	354	+
	355	+ case 2:
	356	+ /* Windows driver values */
	357	+ etd->reg_10 = 0x54;
	358	+ etd->reg_11 = 0x88; /* 0x8a */
	359	+ etd->reg_21 = 0x60; /* 0x00 */
	360	+ if (elantech_write_reg(psmouse, 0x10, etd->reg_10) \|\|
	361	+ elantech_write_reg(psmouse, 0x11, etd->reg_11) \|\|
	362	+ elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
	363	+ rc = -1;
	364	+ break;
	365	+ }
	366	+ /*
	367	+ * Read back reg 0x10. The touchpad is probably initalising
	368	+ * and not ready until we read back the value we just wrote.
	369	+ */
	370	+ do {
	371	+ rc = elantech_read_reg(psmouse, 0x10, &val);
	372	+ if (rc == 0)
	373	+ break;
	374	+ tries--;
	375	+ elantech_debug("elantech.c: retrying read (%d).\n",
	376	+ tries);
	377	+ msleep(ETP_READ_BACK_DELAY);
	378	+ } while (tries > 0);
	379	+ if (rc)
	380	+ pr_err("elantech.c: failed to read back register 0x10.\n");
	381	+ break;
	382	+ }
	383	+
	384	+ if (rc)
	385	+ pr_err("elantech.c: failed to initialise registers.\n");
	386	+
	387	+ return rc;
	388	+}
	389	+
	390	+/*
	391	+ * Set the appropriate event bits for the input subsystem
	392	+ */
	393	+static void elantech_set_input_params(struct psmouse *psmouse)
	394	+{
	395	+ struct input_dev *dev = psmouse->dev;
	396	+ struct elantech_data *etd = psmouse->private;
	397	+
	398	+ __set_bit(EV_KEY, dev->evbit);
	399	+ __set_bit(EV_ABS, dev->evbit);
	400	+
	401	+ __set_bit(BTN_LEFT, dev->keybit);
	402	+ __set_bit(BTN_RIGHT, dev->keybit);
	403	+
	404	+ __set_bit(BTN_TOUCH, dev->keybit);
	405	+ __set_bit(BTN_TOOL_FINGER, dev->keybit);
	406	+ __set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
	407	+ __set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
	408	+
	409	+ switch (etd->hw_version) {
	410	+ case 1:
	411	+ /* Rocker button */
	412	+ if ((etd->fw_version_maj == 0x01) &&
	413	+ (etd->capabilities & ETP_CAP_HAS_ROCKER)) {
	414	+ __set_bit(BTN_FORWARD, dev->keybit);
	415	+ __set_bit(BTN_BACK, dev->keybit);
	416	+ }
	417	+ input_set_abs_params(dev, ABS_X, ETP_XMIN_V1, ETP_XMAX_V1, 0, 0);
	418	+ input_set_abs_params(dev, ABS_Y, ETP_YMIN_V1, ETP_YMAX_V1, 0, 0);
	419	+ break;
	420	+
	421	+ case 2:
	422	+ input_set_abs_params(dev, ABS_X, ETP_XMIN_V2, ETP_XMAX_V2, 0, 0);
	423	+ input_set_abs_params(dev, ABS_Y, ETP_YMIN_V2, ETP_YMAX_V2, 0, 0);
	424	+ input_set_abs_params(dev, ABS_HAT0X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
	425	+ input_set_abs_params(dev, ABS_HAT0Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
	426	+ input_set_abs_params(dev, ABS_HAT1X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
	427	+ input_set_abs_params(dev, ABS_HAT1Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
	428	+ break;
	429	+ }
	430	+}
	431	+
	432	+struct elantech_attr_data {
	433	+ size_t field_offset;
	434	+ unsigned char reg;
	435	+};
	436	+
	437	+/*
	438	+ * Display a register value by reading a sysfs entry
	439	+ */
	440	+static ssize_t elantech_show_int_attr(struct psmouse psmouse, void data,
	441	+ char *buf)
	442	+{
	443	+ struct elantech_data *etd = psmouse->private;
	444	+ struct elantech_attr_data *attr = data;
	445	+ unsigned char reg = (unsigned char ) etd + attr->field_offset;
	446	+ int rc = 0;
	447	+
	448	+ if (attr->reg)
	449	+ rc = elantech_read_reg(psmouse, attr->reg, reg);
	450	+
	451	+ return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
	452	+}
	453	+
	454	+/*
	455	+ * Write a register value by writing a sysfs entry
	456	+ */
	457	+static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
	458	+ void data, const char buf, size_t count)
	459	+{
	460	+ struct elantech_data *etd = psmouse->private;
	461	+ struct elantech_attr_data *attr = data;
	462	+ unsigned char reg = (unsigned char ) etd + attr->field_offset;
	463	+ unsigned long value;
	464	+ int err;
	465	+
	466	+ err = strict_strtoul(buf, 16, &value);
	467	+ if (err)
	468	+ return err;
	469	+
	470	+ if (value > 0xff)
	471	+ return -EINVAL;
	472	+
	473	+ /* Do we need to preserve some bits for version 2 hardware too? */
	474	+ if (etd->hw_version == 1) {
	475	+ if (attr->reg == 0x10)
	476	+ /* Force absolute mode always on */
	477	+ value \|= ETP_R10_ABSOLUTE_MODE;
	478	+ else if (attr->reg == 0x11)
	479	+ /* Force 4 byte mode always on */
	480	+ value \|= ETP_R11_4_BYTE_MODE;
	481	+ }
	482	+
	483	+ if (!attr->reg \|\| elantech_write_reg(psmouse, attr->reg, value) == 0)
	484	+ *reg = value;
	485	+
	486	+ return count;
	487	+}
	488	+
	489	+#define ELANTECH_INT_ATTR(_name, _register) \
	490	+ static struct elantech_attr_data elantech_attr_##_name = { \
	491	+ .field_offset = offsetof(struct elantech_data, _name), \
	492	+ .reg = _register, \
	493	+ }; \
	494	+ PSMOUSE_DEFINE_ATTR(_name, S_IWUSR \| S_IRUGO, \
	495	+ &elantech_attr_##_name, \
	496	+ elantech_show_int_attr, \
	497	+ elantech_set_int_attr)
	498	+
	499	+ELANTECH_INT_ATTR(reg_10, 0x10);
	500	+ELANTECH_INT_ATTR(reg_11, 0x11);
	501	+ELANTECH_INT_ATTR(reg_20, 0x20);
	502	+ELANTECH_INT_ATTR(reg_21, 0x21);
	503	+ELANTECH_INT_ATTR(reg_22, 0x22);
	504	+ELANTECH_INT_ATTR(reg_23, 0x23);
	505	+ELANTECH_INT_ATTR(reg_24, 0x24);
	506	+ELANTECH_INT_ATTR(reg_25, 0x25);
	507	+ELANTECH_INT_ATTR(reg_26, 0x26);
	508	+ELANTECH_INT_ATTR(debug, 0);
	509	+ELANTECH_INT_ATTR(paritycheck, 0);
	510	+
	511	+static struct attribute *elantech_attrs[] = {
	512	+ &psmouse_attr_reg_10.dattr.attr,
	513	+ &psmouse_attr_reg_11.dattr.attr,
	514	+ &psmouse_attr_reg_20.dattr.attr,
	515	+ &psmouse_attr_reg_21.dattr.attr,
	516	+ &psmouse_attr_reg_22.dattr.attr,
	517	+ &psmouse_attr_reg_23.dattr.attr,
	518	+ &psmouse_attr_reg_24.dattr.attr,
	519	+ &psmouse_attr_reg_25.dattr.attr,
	520	+ &psmouse_attr_reg_26.dattr.attr,
	521	+ &psmouse_attr_debug.dattr.attr,
	522	+ &psmouse_attr_paritycheck.dattr.attr,
	523	+ NULL
	524	+};
	525	+
	526	+static struct attribute_group elantech_attr_group = {
	527	+ .attrs = elantech_attrs,
	528	+};
	529	+
	530	+/*
	531	+ * Use magic knock to detect Elantech touchpad
	532	+ */
	533	+int elantech_detect(struct psmouse *psmouse, int set_properties)
	534	+{
	535	+ struct ps2dev *ps2dev = &psmouse->ps2dev;
	536	+ unsigned char param[3];
	537	+
	538	+ ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
	539	+
	540	+ if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) \|\|
	541	+ ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) \|\|
	542	+ ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) \|\|
	543	+ ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) \|\|
	544	+ ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
	545	+ pr_err("elantech.c: sending Elantech magic knock failed.\n");
	546	+ return -1;
	547	+ }
	548	+
	549	+ /*
	550	+ * Report this in case there are Elantech models that use a different
	551	+ * set of magic numbers
	552	+ */
	553	+ if (param[0] != 0x3c \|\| param[1] != 0x03 \|\| param[2] != 0xc8) {
	554	+ pr_info("elantech.c: unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
	555	+ param[0], param[1], param[2]);
	556	+ return -1;
	557	+ }
	558	+
	559	+ if (set_properties) {
	560	+ psmouse->vendor = "Elantech";
	561	+ psmouse->name = "Touchpad";
	562	+ }
	563	+
	564	+ return 0;
	565	+}
	566	+
	567	+/*
	568	+ * Clean up sysfs entries when disconnecting
	569	+ */
	570	+static void elantech_disconnect(struct psmouse *psmouse)
	571	+{
	572	+ sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
	573	+ &elantech_attr_group);
	574	+ kfree(psmouse->private);
	575	+ psmouse->private = NULL;
	576	+}
	577	+
	578	+/*
	579	+ * Put the touchpad back into absolute mode when reconnecting
	580	+ */
	581	+static int elantech_reconnect(struct psmouse *psmouse)
	582	+{
	583	+ if (elantech_detect(psmouse, 0))
	584	+ return -1;
	585	+
	586	+ if (elantech_set_absolute_mode(psmouse)) {
	587	+ pr_err("elantech.c: failed to put touchpad back into absolute mode.\n");
	588	+ return -1;
	589	+ }
	590	+
	591	+ return 0;
	592	+}
	593	+
	594	+/*
	595	+ * Initialize the touchpad and create sysfs entries
	596	+ */
	597	+int elantech_init(struct psmouse *psmouse)
	598	+{
	599	+ struct elantech_data *etd;
	600	+ int i, error;
	601	+ unsigned char param[3];
	602	+
	603	+ etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
	604	+ psmouse->private = etd;
	605	+ if (!etd)
	606	+ return -1;
	607	+
	608	+ etd->parity[0] = 1;
	609	+ for (i = 1; i < 256; i++)
	610	+ etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
	611	+
	612	+ /*
	613	+ * Find out what version hardware this is
	614	+ */
	615	+ if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
	616	+ pr_err("elantech.c: failed to query firmware version.\n");
	617	+ goto init_fail;
	618	+ }
	619	+ pr_info("elantech.c: Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
	620	+ param[0], param[1], param[2]);
	621	+ etd->fw_version_maj = param[0];
	622	+ etd->fw_version_min = param[2];
	623	+
	624	+ /*
	625	+ * Assume every version greater than this is new EeePC style
	626	+ * hardware with 6 byte packets
	627	+ */
	628	+ if (etd->fw_version_maj >= 0x02 && etd->fw_version_min >= 0x30) {
	629	+ etd->hw_version = 2;
	630	+ /* For now show extra debug information */
	631	+ etd->debug = 1;
	632	+ /* Don't know how to do parity checking for version 2 */
	633	+ etd->paritycheck = 0;
	634	+ } else {
	635	+ etd->hw_version = 1;
	636	+ etd->paritycheck = 1;
	637	+ }
	638	+ pr_info("elantech.c: assuming hardware version %d, firmware version %d.%d\n",
	639	+ etd->hw_version, etd->fw_version_maj, etd->fw_version_min);
	640	+
	641	+ if (synaptics_send_cmd(psmouse, ETP_CAPABILITIES_QUERY, param)) {
	642	+ pr_err("elantech.c: failed to query capabilities.\n");
	643	+ goto init_fail;
	644	+ }
	645	+ pr_info("elantech.c: Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
	646	+ param[0], param[1], param[2]);
	647	+ etd->capabilities = param[0];
	648	+
	649	+ if (elantech_set_absolute_mode(psmouse)) {
	650	+ pr_err("elantech.c: failed to put touchpad into absolute mode.\n");
	651	+ goto init_fail;
	652	+ }
	653	+
	654	+ elantech_set_input_params(psmouse);
	655	+
	656	+ error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
	657	+ &elantech_attr_group);
	658	+ if (error) {
	659	+ pr_err("elantech.c: failed to create sysfs attributes, error: %d.\n",
	660	+ error);
	661	+ goto init_fail;
	662	+ }
	663	+
	664	+ psmouse->protocol_handler = elantech_process_byte;
	665	+ psmouse->disconnect = elantech_disconnect;
	666	+ psmouse->reconnect = elantech_reconnect;
	667	+ psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;
	668	+
	669	+ return 0;
	670	+
	671	+ init_fail:
	672	+ kfree(etd);
	673	+ return -1;
	674	+}
...	...	@@ -29,6 +29,7 @@
29	29	#include "lifebook.h"
30	30	#include "trackpoint.h"
31	31	#include "touchkit_ps2.h"
	32	+#include "elantech.h"
32	33
33	34	#define DRIVER_DESC "PS/2 mouse driver"
34	35
...	...	@@ -650,6 +651,19 @@
650	651	max_proto = PSMOUSE_IMEX;
651	652	}
652	653
	654	+/*
	655	+ * Try Elantech touchpad.
	656	+ */
	657	+ if (max_proto > PSMOUSE_IMEX &&
	658	+ elantech_detect(psmouse, set_properties) == 0) {
	659	+ if (!set_properties \|\| elantech_init(psmouse) == 0)
	660	+ return PSMOUSE_ELANTECH;
	661	+/*
	662	+ * Init failed, try basic relative protocols
	663	+ */
	664	+ max_proto = PSMOUSE_IMEX;
	665	+ }
	666	+
653	667	if (max_proto > PSMOUSE_IMEX) {
654	668	if (genius_detect(psmouse, set_properties) == 0)
655	669	return PSMOUSE_GENPS;
...	...	@@ -789,6 +803,15 @@
789	803	.detect = hgpk_detect,
790	804	},
791	805	#endif
	806	+#ifdef CONFIG_MOUSE_PS2_ELANTECH
	807	+ {
	808	+ .type = PSMOUSE_ELANTECH,
	809	+ .name = "ETPS/2",
	810	+ .alias = "elantech",
	811	+ .detect = elantech_detect,
	812	+ .init = elantech_init,
	813	+ },
	814	+ #endif
792	815	{
793	816	.type = PSMOUSE_CORTRON,
794	817	.name = "CortronPS/2",
...	...	@@ -90,6 +90,7 @@
90	90	PSMOUSE_TOUCHKIT_PS2,
91	91	PSMOUSE_CORTRON,
92	92	PSMOUSE_HGPK,
	93	+ PSMOUSE_ELANTECH,
93	94	PSMOUSE_AUTO /* This one should always be last */
94	95	};
95	96