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>

1 files changed, 124 insertions, 0 deletions

diff --git a/drivers/input/mouse/elantech.h b/drivers/input/mouse/elantech.h
new file mode 100644
index 00000000000..bee282b540b
--- /dev/null
+++ b/drivers/input/mouse/elantech.h
@@ -0,0 +1,124 @@
+/*
+ * 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