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>

drivers/input/mouse/Kconfig

@@ -25,8 +25,8 @@ config MOUSE_PS2
 	  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>
@@ -87,6 +87,27 @@ config MOUSE_PS2_TRACKPOINT
 
 	  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"
 	depends on MOUSE_PS2

drivers/input/mouse/Makefile

@@ -21,6 +21,7 @@ obj-$(CONFIG_MOUSE_GPIO)	+= gpio_mouse.o
 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

drivers/input/mouse/elantech.h

+/*
+ * 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

drivers/input/mouse/psmouse-base.c

@@ -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 @@ static int psmouse_extensions(struct psmouse *psmouse,
 		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 @@ static const struct psmouse_protocol psmouse_protocols[] = {
 		.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",

drivers/input/mouse/psmouse.h

@@ -90,6 +90,7 @@ enum psmouse_type {
 	PSMOUSE_TOUCHKIT_PS2,
 	PSMOUSE_CORTRON,
 	PSMOUSE_HGPK,
+	PSMOUSE_ELANTECH,
 	PSMOUSE_AUTO		/* This one should always be last */
 };