[PATCH] Alps dualpoint touchpads losing sync [buttons fixed too]

[Sebastian Kapfer <sebastian_kapfer@gmx.net>]

Fix Alps dualpoint touchpads (at the very least Dell E6x00 series)
losing sync when touchpad and trackpoint are used at the same time.
Hardware sends a different packet format than when either is used alone.
This format was not recognised by the existing Alps driver.

This is slightly changed from the first patch, hanging buttons issue has
been ironed out.

Has been tested by a number of people so far with good results.

---
 drivers/input/mouse/alps.c    |  107 +++++++++++++++++++++++++++++++++++++----
 drivers/input/mouse/psmouse.h |    2 +-
 2 files changed, 99 insertions(+), 10 deletions(-)

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index f361106..aaab238 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -1,14 +1,20 @@
-/*
+/* vim:noet:sw=8:ts=8
  * ALPS touchpad PS/2 mouse driver
  *
  * Copyright (c) 2003 Neil Brown <neilb@cse.unsw.edu.au>
  * Copyright (c) 2003-2005 Peter Osterlund <petero2@telia.com>
  * Copyright (c) 2004 Dmitry Torokhov <dtor@mail.ru>
  * Copyright (c) 2005 Vojtech Pavlik <vojtech@suse.cz>
+ * Copyright (c) 2009 Sebastian Kapfer <sebastian_kapfer@gmx.net>
  *
  * ALPS detection, tap switching and status querying info is taken from
  * tpconfig utility (by C. Scott Ananian and Bruce Kall).
  *
+ * Inspiration for parts of the multitouch codepath from a patch by
+ * Matthew Chapman.  (See http://lkml.org/lkml/2008/12/8/182 )
+ * Additional research by David Kubicek and Erik Osterholm
+ * (https://bugs.launchpad.net/ubuntu/+source/linux/+bug/296610 )
+ *
  * 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.
@@ -35,6 +41,15 @@
 #define ALPS_OLDPROTO	0x10
 #define ALPS_PASS	0x20
 #define ALPS_FW_BK_2	0x40
+/* capable of sending 9-byte packets.  these packets are recognized by having
+ * LMR buttons set.  if there were a dualpoint device with three mouse buttons,
+ * we could misrecognize, so an additional flag.  if your dualpoint device
+ * often loses sync, try adding ALPS_DUALPOINT9.
+ * these devices also have the property that they don't keep button state
+ * separate for the touchpad and stick device. */
+#define ALPS_DUALPOINT9	0x80
+
+#define DELL_STYLE_DUALPOINT (ALPS_DUALPOINT|ALPS_DUALPOINT9|ALPS_PASS)
 
 static const struct alps_model_info alps_model_data[] = {
 	{ { 0x32, 0x02, 0x14 },	0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT }, /* Toshiba Salellite Pro M10 */
@@ -55,7 +70,8 @@ static const struct alps_model_info alps_model_data[] = {
 	{ { 0x20, 0x02, 0x0e },	0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT }, /* XXX */
 	{ { 0x22, 0x02, 0x0a },	0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT },
 	{ { 0x22, 0x02, 0x14 }, 0xff, 0xff, ALPS_PASS | ALPS_DUALPOINT }, /* Dell Latitude D600 */
-	{ { 0x62, 0x02, 0x14 }, 0xcf, 0xcf, ALPS_PASS | ALPS_DUALPOINT }, /* Dell Latitude E6500 */
+	/* Dell Latitude E6400, E6500, Precision M4400 */
+	{ { 0x62, 0x02, 0x14 }, 0xcf, 0xcf, DELL_STYLE_DUALPOINT },
 	{ { 0x73, 0x02, 0x50 }, 0xcf, 0xcf, ALPS_FW_BK_1 },		  /* Dell Vostro 1400 */
 };
 
@@ -65,8 +81,13 @@ static const struct alps_model_info alps_model_data[] = {
  * isn't valid per PS/2 spec.
  */
 
-/*
- * ALPS abolute Mode - new format
+/* PS/2 packet format
+ *
+ * byte 0: YOFL XOFL YSGN XSGN  1    M    R    L
+ * byte 1: X7   X6   X5   X4   X3   X2   X1   X0
+ * byte 2: Y7   Y6   Y5   Y4   Y3   Y2   Y1   Y0
+ *
+ * ALPS absolute Mode - new format
  *
  * byte 0:  1    ?    ?    ?    1    ?    ?    ?
  * byte 1:  0   x6   x5   x4   x3   x2   x1   x0
@@ -75,6 +96,20 @@ static const struct alps_model_info alps_model_data[] = {
  * byte 4:  0   y6   y5   y4   y3   y2   y1   y0
  * byte 5:  0   z6   z5   z4   z3   z2   z1   z0
  *
+ * Dualpoint device -- 9-byte packet format
+ *
+ * byte 0:    1    1    0    0    1    1    1    1
+ * byte 1:    0   x6   x5   x4   x3   x2   x1   x0
+ * byte 2:    0  x10   x9   x8   x7    0  fin  ges
+ * byte 3: YOFL XOFL YSGN XSGN    1    1    1    1
+ * byte 4:   X7   X6   X5   X4   X3   X2   X1   X0
+ * byte 5:   Y7   Y6   Y5   Y4   Y3   Y2   Y1   Y0
+ * byte 6:    0   y9   y8   y7    1    m    r    l
+ * byte 7:    0   y6   y5   y4   y3   y2   y1   y0
+ * byte 8:    0   z6   z5   z4   z3   z2   z1   z0
+ *
+ * CAPITALS = stick, miniscules = touchpad
+ *
  * ?'s can have different meanings on different models,
  * such as wheel rotation, extra buttons, stick buttons
  * on a dualpoint, etc.
@@ -98,9 +133,30 @@ static void alps_process_packet(struct psmouse *psmouse)
 		input_report_rel(dev2, REL_Y,
 			packet[2] ? ((packet[0] << 3) & 0x100) - packet[2] : 0);
 		input_sync(dev2);
+		if ((priv->i->flags & ALPS_DUALPOINT9) == 0)
+			return;
+		/* copy state to other input layer device, since
+		 * the hardware does not keep them separate. */
+		input_report_key(dev,  BTN_LEFT,   packet[0] & 1);
+		input_report_key(dev,  BTN_RIGHT,  packet[0] & 2);
+		input_report_key(dev,  BTN_MIDDLE, packet[0] & 4);
+		input_sync(dev);
 		return;
 	}
 
+	/* handle trackpoint part of a 9-byte packet,
+	   pass the rest on. */
+	if (priv->i->flags & ALPS_DUALPOINT9 && (packet[3] & 0xf) == 0xf) {
+		input_report_rel(dev2, REL_X,
+			packet[4] ? packet[4] - ((packet[3] << 4) & 0x100) : 0);
+		input_report_rel(dev2, REL_Y,
+			packet[5] ? ((packet[3] << 3) & 0x100) - packet[5] : 0);
+		/* touchpad data and buttons are handled below */
+		packet[3] = packet[6];
+		packet[4] = packet[7];
+		packet[5] = packet[8];
+	}
+
 	if (priv->i->flags & ALPS_OLDPROTO) {
 		left = packet[2] & 0x10;
 		right = packet[2] & 0x08;
@@ -148,6 +204,14 @@ static void alps_process_packet(struct psmouse *psmouse)
 	input_report_key(dev, BTN_LEFT, left);
 	input_report_key(dev, BTN_RIGHT, right);
 	input_report_key(dev, BTN_MIDDLE, middle);
+	/* copy state to other input layer device, since
+	 * the hardware does not keep them separate. */
+	if (priv->i->flags & ALPS_DUALPOINT9) {
+		input_report_key(dev2, BTN_LEFT,   left);
+		input_report_key(dev2, BTN_RIGHT,  right);
+		input_report_key(dev2, BTN_MIDDLE, middle);
+		input_sync(dev2);
+	}
 
 	/* Convert hardware tap to a reasonable Z value */
 	if (ges && !fin) z = 40;
@@ -191,6 +255,7 @@ static void alps_process_packet(struct psmouse *psmouse)
 static psmouse_ret_t alps_process_byte(struct psmouse *psmouse)
 {
 	struct alps_data *priv = psmouse->private;
+	int length_full_packet = 6;
 
 	if ((psmouse->packet[0] & 0xc8) == 0x08) { /* PS/2 packet */
 		if (psmouse->pktcnt == 3) {
@@ -200,15 +265,39 @@ static psmouse_ret_t alps_process_byte(struct psmouse *psmouse)
 		return PSMOUSE_GOOD_DATA;
 	}
 
-	if ((psmouse->packet[0] & priv->i->mask0) != priv->i->byte0)
+	/* must have been a non-PS/2 packet to even get here. */
+
+	if ((psmouse->packet[0] & priv->i->mask0) != priv->i->byte0) {
+		dbg("don't like packet[0] = %x (mask0 = %x, byte0 = %x\n",
+		    (int)psmouse->packet[0],
+		    (int)priv->i->mask0,
+		    (int)priv->i->byte0);
 		return PSMOUSE_BAD_DATA;
+	}
 
-	/* Bytes 2 - 6 should have 0 in the highest bit */
-	if (psmouse->pktcnt >= 2 && psmouse->pktcnt <= 6 &&
-	    (psmouse->packet[psmouse->pktcnt - 1] & 0x80))
+	/* 9-byte packet format by dualpoint units */
+	if (priv->i->flags & ALPS_DUALPOINT9) {
+		/* is marked by a packet with LMR set */
+		if ((psmouse->pktcnt >= 4)
+		    && ((psmouse->packet[3] & 0xf) == 0xf)) {
+			length_full_packet = 9;
+			/* wave stick bytes through */
+			if (psmouse->pktcnt <= 6)
+				return PSMOUSE_GOOD_DATA;
+		}
+	}
+
+	/* Bytes 2 - 6 should have 0 in the highest bit for 6-byte packet */
+	/* Bytes 2, 3, and 7 through 9 should have for 9-byte packet      */
+	if (psmouse->pktcnt >= 2 &&
+	    (psmouse->packet[psmouse->pktcnt - 1] & 0x80)) {
+		dbg("don't like packet[%i] = %x\n",
+		    psmouse->pktcnt - 1,
+		    (int)psmouse->packet[psmouse->pktcnt - 1]);
 		return PSMOUSE_BAD_DATA;
+	}
 
-	if (psmouse->pktcnt == 6) {
+	if (psmouse->pktcnt == length_full_packet) {
 		alps_process_packet(psmouse);
 		return PSMOUSE_FULL_PACKET;
 	}
diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
index e053bdd..d4772fe 100644
--- a/drivers/input/mouse/psmouse.h
+++ b/drivers/input/mouse/psmouse.h
@@ -42,7 +42,7 @@ struct psmouse {
 	struct delayed_work resync_work;
 	char *vendor;
 	char *name;
-	unsigned char packet[8];
+	unsigned char packet[9];
 	unsigned char badbyte;
 	unsigned char pktcnt;
 	unsigned char pktsize;
-- 
1.6.3.3