Input: ALPS - add support for protocol versions 3 and 4

This patch adds support for two ALPS touchpad protocols not
supported currently by the driver, which I am arbitrarily naming
version 3 and version 4. Support is single-touch only at this time,
although both protocols are capable of limited multitouch support.

Thanks to Andrew Skalski, who did the initial reverse-engineering
of the v3 protocol.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Chase Douglas <chase.douglas@canonical.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 44a0a71..a0248fd 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -23,6 +23,50 @@
 #include "psmouse.h"
 #include "alps.h"
 
+/*
+ * Definitions for ALPS version 3 and 4 command mode protocol
+ */
+#define ALPS_CMD_NIBBLE_10	0x01f2
+
+static const struct alps_nibble_commands alps_v3_nibble_commands[] = {
+	{ PSMOUSE_CMD_SETPOLL,		0x00 }, /* 0 */
+	{ PSMOUSE_CMD_RESET_DIS,	0x00 }, /* 1 */
+	{ PSMOUSE_CMD_SETSCALE21,	0x00 }, /* 2 */
+	{ PSMOUSE_CMD_SETRATE,		0x0a }, /* 3 */
+	{ PSMOUSE_CMD_SETRATE,		0x14 }, /* 4 */
+	{ PSMOUSE_CMD_SETRATE,		0x28 }, /* 5 */
+	{ PSMOUSE_CMD_SETRATE,		0x3c }, /* 6 */
+	{ PSMOUSE_CMD_SETRATE,		0x50 }, /* 7 */
+	{ PSMOUSE_CMD_SETRATE,		0x64 }, /* 8 */
+	{ PSMOUSE_CMD_SETRATE,		0xc8 }, /* 9 */
+	{ ALPS_CMD_NIBBLE_10,		0x00 }, /* a */
+	{ PSMOUSE_CMD_SETRES,		0x00 }, /* b */
+	{ PSMOUSE_CMD_SETRES,		0x01 }, /* c */
+	{ PSMOUSE_CMD_SETRES,		0x02 }, /* d */
+	{ PSMOUSE_CMD_SETRES,		0x03 }, /* e */
+	{ PSMOUSE_CMD_SETSCALE11,	0x00 }, /* f */
+};
+
+static const struct alps_nibble_commands alps_v4_nibble_commands[] = {
+	{ PSMOUSE_CMD_ENABLE,		0x00 }, /* 0 */
+	{ PSMOUSE_CMD_RESET_DIS,	0x00 }, /* 1 */
+	{ PSMOUSE_CMD_SETSCALE21,	0x00 }, /* 2 */
+	{ PSMOUSE_CMD_SETRATE,		0x0a }, /* 3 */
+	{ PSMOUSE_CMD_SETRATE,		0x14 }, /* 4 */
+	{ PSMOUSE_CMD_SETRATE,		0x28 }, /* 5 */
+	{ PSMOUSE_CMD_SETRATE,		0x3c }, /* 6 */
+	{ PSMOUSE_CMD_SETRATE,		0x50 }, /* 7 */
+	{ PSMOUSE_CMD_SETRATE,		0x64 }, /* 8 */
+	{ PSMOUSE_CMD_SETRATE,		0xc8 }, /* 9 */
+	{ ALPS_CMD_NIBBLE_10,		0x00 }, /* a */
+	{ PSMOUSE_CMD_SETRES,		0x00 }, /* b */
+	{ PSMOUSE_CMD_SETRES,		0x01 }, /* c */
+	{ PSMOUSE_CMD_SETRES,		0x02 }, /* d */
+	{ PSMOUSE_CMD_SETRES,		0x03 }, /* e */
+	{ PSMOUSE_CMD_SETSCALE11,	0x00 }, /* f */
+};
+
+
 #define ALPS_DUALPOINT		0x02	/* touchpad has trackstick */
 #define ALPS_PASS		0x04	/* device has a pass-through port */
 
@@ -34,30 +78,33 @@
 					   6-byte ALPS packet */
 
 static const struct alps_model_info alps_model_data[] = {
-	{ { 0x32, 0x02, 0x14 },	ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT }, /* Toshiba Salellite Pro M10 */
-	{ { 0x33, 0x02, 0x0a },	ALPS_PROTO_V1, 0x88, 0xf8, 0 },				 /* UMAX-530T */
-	{ { 0x53, 0x02, 0x0a },	ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
-	{ { 0x53, 0x02, 0x14 },	ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
-	{ { 0x60, 0x03, 0xc8 }, ALPS_PROTO_V2, 0xf8, 0xf8, 0 },				 /* HP ze1115 */
-	{ { 0x63, 0x02, 0x0a },	ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
-	{ { 0x63, 0x02, 0x14 },	ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
-	{ { 0x63, 0x02, 0x28 },	ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_FW_BK_2 },		 /* Fujitsu Siemens S6010 */
-	{ { 0x63, 0x02, 0x3c },	ALPS_PROTO_V2, 0x8f, 0x8f, ALPS_WHEEL },		 /* Toshiba Satellite S2400-103 */
-	{ { 0x63, 0x02, 0x50 },	ALPS_PROTO_V2, 0xef, 0xef, ALPS_FW_BK_1 },		 /* NEC Versa L320 */
-	{ { 0x63, 0x02, 0x64 },	ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
-	{ { 0x63, 0x03, 0xc8 }, ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT }, /* Dell Latitude D800 */
-	{ { 0x73, 0x00, 0x0a },	ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_DUALPOINT },		 /* ThinkPad R61 8918-5QG */
-	{ { 0x73, 0x02, 0x0a },	ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
-	{ { 0x73, 0x02, 0x14 },	ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_FW_BK_2 },		 /* Ahtec Laptop */
-	{ { 0x20, 0x02, 0x0e },	ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT }, /* XXX */
-	{ { 0x22, 0x02, 0x0a },	ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT },
-	{ { 0x22, 0x02, 0x14 }, ALPS_PROTO_V2, 0xff, 0xff, ALPS_PASS | ALPS_DUALPOINT }, /* Dell Latitude D600 */
+	{ { 0x32, 0x02, 0x14 },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT },	/* Toshiba Salellite Pro M10 */
+	{ { 0x33, 0x02, 0x0a },	0x00, ALPS_PROTO_V1, 0x88, 0xf8, 0 },				/* UMAX-530T */
+	{ { 0x53, 0x02, 0x0a },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
+	{ { 0x53, 0x02, 0x14 },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
+	{ { 0x60, 0x03, 0xc8 }, 0x00, ALPS_PROTO_V2, 0xf8, 0xf8, 0 },				/* HP ze1115 */
+	{ { 0x63, 0x02, 0x0a },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
+	{ { 0x63, 0x02, 0x14 },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
+	{ { 0x63, 0x02, 0x28 },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_FW_BK_2 },		/* Fujitsu Siemens S6010 */
+	{ { 0x63, 0x02, 0x3c },	0x00, ALPS_PROTO_V2, 0x8f, 0x8f, ALPS_WHEEL },			/* Toshiba Satellite S2400-103 */
+	{ { 0x63, 0x02, 0x50 },	0x00, ALPS_PROTO_V2, 0xef, 0xef, ALPS_FW_BK_1 },		/* NEC Versa L320 */
+	{ { 0x63, 0x02, 0x64 },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
+	{ { 0x63, 0x03, 0xc8 }, 0x00, ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT },	/* Dell Latitude D800 */
+	{ { 0x73, 0x00, 0x0a },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_DUALPOINT },		/* ThinkPad R61 8918-5QG */
+	{ { 0x73, 0x02, 0x0a },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, 0 },
+	{ { 0x73, 0x02, 0x14 },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_FW_BK_2 },		/* Ahtec Laptop */
+	{ { 0x20, 0x02, 0x0e },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT },	/* XXX */
+	{ { 0x22, 0x02, 0x0a },	0x00, ALPS_PROTO_V2, 0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT },
+	{ { 0x22, 0x02, 0x14 }, 0x00, ALPS_PROTO_V2, 0xff, 0xff, ALPS_PASS | ALPS_DUALPOINT },	/* Dell Latitude D600 */
 	/* Dell Latitude E5500, E6400, E6500, Precision M4400 */
-	{ { 0x62, 0x02, 0x14 }, ALPS_PROTO_V2, 0xcf, 0xcf,
+	{ { 0x62, 0x02, 0x14 }, 0x00, ALPS_PROTO_V2, 0xcf, 0xcf,
 		ALPS_PASS | ALPS_DUALPOINT | ALPS_PS2_INTERLEAVED },
-	{ { 0x73, 0x02, 0x50 }, ALPS_PROTO_V2, 0xcf, 0xcf, ALPS_FOUR_BUTTONS },		 /* Dell Vostro 1400 */
-	{ { 0x52, 0x01, 0x14 }, ALPS_PROTO_V2, 0xff, 0xff,
-		ALPS_PASS | ALPS_DUALPOINT | ALPS_PS2_INTERLEAVED },			 /* Toshiba Tecra A11-11L */
+	{ { 0x73, 0x02, 0x50 }, 0x00, ALPS_PROTO_V2, 0xcf, 0xcf, ALPS_FOUR_BUTTONS },		/* Dell Vostro 1400 */
+	{ { 0x52, 0x01, 0x14 }, 0x00, ALPS_PROTO_V2, 0xff, 0xff,
+		ALPS_PASS | ALPS_DUALPOINT | ALPS_PS2_INTERLEAVED },				/* Toshiba Tecra A11-11L */
+	{ { 0x73, 0x02, 0x64 },	0x9b, ALPS_PROTO_V3, 0x8f, 0x8f, ALPS_DUALPOINT },
+	{ { 0x73, 0x02, 0x64 },	0x9d, ALPS_PROTO_V3, 0x8f, 0x8f, ALPS_DUALPOINT },
+	{ { 0x73, 0x02, 0x64 },	0x8a, ALPS_PROTO_V4, 0x8f, 0x8f, 0 },
 };
 
 /*
@@ -101,7 +148,7 @@
 	input_sync(dev2);
 }
 
-static void alps_process_packet(struct psmouse *psmouse)
+static void alps_process_packet_v1_v2(struct psmouse *psmouse)
 {
 	struct alps_data *priv = psmouse->private;
 	const struct alps_model_info *model = priv->i;
@@ -203,6 +250,224 @@
 	input_sync(dev);
 }
 
+static void alps_process_trackstick_packet_v3(struct psmouse *psmouse)
+{
+	struct alps_data *priv = psmouse->private;
+	unsigned char *packet = psmouse->packet;
+	struct input_dev *dev = priv->dev2;
+	int x, y, z, left, right, middle;
+
+	/* Sanity check packet */
+	if (!(packet[0] & 0x40)) {
+		psmouse_dbg(psmouse, "Bad trackstick packet, discarding\n");
+		return;
+	}
+
+	/*
+	 * There's a special packet that seems to indicate the end
+	 * of a stream of trackstick data. Filter these out.
+	 */
+	if (packet[1] == 0x7f && packet[2] == 0x7f && packet[4] == 0x7f)
+		return;
+
+	x = (s8)(((packet[0] & 0x20) << 2) | (packet[1] & 0x7f));
+	y = (s8)(((packet[0] & 0x10) << 3) | (packet[2] & 0x7f));
+	z = (packet[4] & 0x7c) >> 2;
+
+	/*
+	 * The x and y values tend to be quite large, and when used
+	 * alone the trackstick is difficult to use. Scale them down
+	 * to compensate.
+	 */
+	x /= 8;
+	y /= 8;
+
+	input_report_rel(dev, REL_X, x);
+	input_report_rel(dev, REL_Y, -y);
+
+	/*
+	 * Most ALPS models report the trackstick buttons in the touchpad
+	 * packets, but a few report them here. No reliable way has been
+	 * found to differentiate between the models upfront, so we enable
+	 * the quirk in response to seeing a button press in the trackstick
+	 * packet.
+	 */
+	left = packet[3] & 0x01;
+	right = packet[3] & 0x02;
+	middle = packet[3] & 0x04;
+
+	if (!(priv->quirks & ALPS_QUIRK_TRACKSTICK_BUTTONS) &&
+	    (left || right || middle))
+		priv->quirks |= ALPS_QUIRK_TRACKSTICK_BUTTONS;
+
+	if (priv->quirks & ALPS_QUIRK_TRACKSTICK_BUTTONS) {
+		input_report_key(dev, BTN_LEFT, left);
+		input_report_key(dev, BTN_RIGHT, right);
+		input_report_key(dev, BTN_MIDDLE, middle);
+	}
+
+	input_sync(dev);
+	return;
+}
+
+static void alps_process_touchpad_packet_v3(struct psmouse *psmouse)
+{
+	struct alps_data *priv = psmouse->private;
+	unsigned char *packet = psmouse->packet;
+	struct input_dev *dev = psmouse->dev;
+	struct input_dev *dev2 = priv->dev2;
+	int x, y, z;
+	int left, right, middle;
+
+	/*
+	 * There's no single feature of touchpad position and bitmap
+	 * packets that can be used to distinguish between them. We
+	 * rely on the fact that a bitmap packet should always follow
+	 * a position packet with bit 6 of packet[4] set.
+	 */
+	if (priv->multi_packet) {
+		priv->multi_packet = 0;
+
+		/*
+		 * Sometimes a position packet will indicate a multi-packet
+		 * sequence, but then what follows is another position
+		 * packet. Check for this, and when it happens process the
+		 * position packet as usual.
+		 */
+		if (packet[0] & 0x40) {
+			/*
+			 * Bitmap packets are not yet supported, so for now
+			 * just ignore them.
+			 */
+			return;
+		}
+	}
+
+	if (!priv->multi_packet && (packet[4] & 0x40))
+		priv->multi_packet = 1;
+	else
+		priv->multi_packet = 0;
+
+	left = packet[3] & 0x01;
+	right = packet[3] & 0x02;
+	middle = packet[3] & 0x04;
+
+	x = ((packet[1] & 0x7f) << 4) | ((packet[4] & 0x30) >> 2) |
+	    ((packet[0] & 0x30) >> 4);
+	y = ((packet[2] & 0x7f) << 4) | (packet[4] & 0x0f);
+	z = packet[5] & 0x7f;
+
+	/*
+	 * Sometimes the hardware sends a single packet with z = 0
+	 * in the middle of a stream. Real releases generate packets
+	 * with x, y, and z all zero, so these seem to be flukes.
+	 * Ignore them.
+	 */
+	if (x && y && !z)
+		return;
+
+	if (z >= 64)
+		input_report_key(dev, BTN_TOUCH, 1);
+	else
+		input_report_key(dev, BTN_TOUCH, 0);
+
+	if (z > 0) {
+		input_report_abs(dev, ABS_X, x);
+		input_report_abs(dev, ABS_Y, y);
+	}
+	input_report_abs(dev, ABS_PRESSURE, z);
+
+	input_report_key(dev, BTN_TOOL_FINGER, z > 0);
+	input_report_key(dev, BTN_LEFT, left);
+	input_report_key(dev, BTN_RIGHT, right);
+	input_report_key(dev, BTN_MIDDLE, middle);
+
+	input_sync(dev);
+
+	if (!(priv->quirks & ALPS_QUIRK_TRACKSTICK_BUTTONS)) {
+		left = packet[3] & 0x10;
+		right = packet[3] & 0x20;
+		middle = packet[3] & 0x40;
+
+		input_report_key(dev2, BTN_LEFT, left);
+		input_report_key(dev2, BTN_RIGHT, right);
+		input_report_key(dev2, BTN_MIDDLE, middle);
+		input_sync(dev2);
+	}
+}
+
+static void alps_process_packet_v3(struct psmouse *psmouse)
+{
+	unsigned char *packet = psmouse->packet;
+
+	/*
+	 * v3 protocol packets come in three types, two representing
+	 * touchpad data and one representing trackstick data.
+	 * Trackstick packets seem to be distinguished by always
+	 * having 0x3f in the last byte. This value has never been
+	 * observed in the last byte of either of the other types
+	 * of packets.
+	 */
+	if (packet[5] == 0x3f) {
+		alps_process_trackstick_packet_v3(psmouse);
+		return;
+	}
+
+	alps_process_touchpad_packet_v3(psmouse);
+}
+
+static void alps_process_packet_v4(struct psmouse *psmouse)
+{
+	unsigned char *packet = psmouse->packet;
+	struct input_dev *dev = psmouse->dev;
+	int x, y, z;
+	int left, right;
+
+	left = packet[4] & 0x01;
+	right = packet[4] & 0x02;
+
+	x = ((packet[1] & 0x7f) << 4) | ((packet[3] & 0x30) >> 2) |
+	    ((packet[0] & 0x30) >> 4);
+	y = ((packet[2] & 0x7f) << 4) | (packet[3] & 0x0f);
+	z = packet[5] & 0x7f;
+
+	if (z >= 64)
+		input_report_key(dev, BTN_TOUCH, 1);
+	else
+		input_report_key(dev, BTN_TOUCH, 0);
+
+	if (z > 0) {
+		input_report_abs(dev, ABS_X, x);
+		input_report_abs(dev, ABS_Y, y);
+	}
+	input_report_abs(dev, ABS_PRESSURE, z);
+
+	input_report_key(dev, BTN_TOOL_FINGER, z > 0);
+	input_report_key(dev, BTN_LEFT, left);
+	input_report_key(dev, BTN_RIGHT, right);
+
+	input_sync(dev);
+}
+
+static void alps_process_packet(struct psmouse *psmouse)
+{
+	struct alps_data *priv = psmouse->private;
+	const struct alps_model_info *model = priv->i;
+
+	switch (model->proto_version) {
+	case ALPS_PROTO_V1:
+	case ALPS_PROTO_V2:
+		alps_process_packet_v1_v2(psmouse);
+		break;
+	case ALPS_PROTO_V3:
+		alps_process_packet_v3(psmouse);
+		break;
+	case ALPS_PROTO_V4:
+		alps_process_packet_v4(psmouse);
+		break;
+	}
+}
+
 static void alps_report_bare_ps2_packet(struct psmouse *psmouse,
 					unsigned char packet[],
 					bool report_buttons)
@@ -376,11 +641,127 @@
 	return PSMOUSE_GOOD_DATA;
 }
 
+static int alps_command_mode_send_nibble(struct psmouse *psmouse, int nibble)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	struct alps_data *priv = psmouse->private;
+	int command;
+	unsigned char *param;
+	unsigned char dummy[4];
+
+	BUG_ON(nibble > 0xf);
+
+	command = priv->nibble_commands[nibble].command;
+	param = (command & 0x0f00) ?
+		dummy : (unsigned char *)&priv->nibble_commands[nibble].data;
+
+	if (ps2_command(ps2dev, param, command))
+		return -1;
+
+	return 0;
+}
+
+static int alps_command_mode_set_addr(struct psmouse *psmouse, int addr)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	struct alps_data *priv = psmouse->private;
+	int i, nibble;
+
+	if (ps2_command(ps2dev, NULL, priv->addr_command))
+		return -1;
+
+	for (i = 12; i >= 0; i -= 4) {
+		nibble = (addr >> i) & 0xf;
+		if (alps_command_mode_send_nibble(psmouse, nibble))
+			return -1;
+	}
+
+	return 0;
+}
+
+static int __alps_command_mode_read_reg(struct psmouse *psmouse, int addr)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	unsigned char param[4];
+
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
+		return -1;
+
+	/*
+	 * The address being read is returned in the first two bytes
+	 * of the result. Check that this address matches the expected
+	 * address.
+	 */
+	if (addr != ((param[0] << 8) | param[1]))
+		return -1;
+
+	return param[2];
+}
+
+static int alps_command_mode_read_reg(struct psmouse *psmouse, int addr)
+{
+	if (alps_command_mode_set_addr(psmouse, addr))
+		return -1;
+	return __alps_command_mode_read_reg(psmouse, addr);
+}
+
+static int __alps_command_mode_write_reg(struct psmouse *psmouse, u8 value)
+{
+	if (alps_command_mode_send_nibble(psmouse, (value >> 4) & 0xf))
+		return -1;
+	if (alps_command_mode_send_nibble(psmouse, value & 0xf))
+		return -1;
+	return 0;
+}
+
+static int alps_command_mode_write_reg(struct psmouse *psmouse, int addr,
+				       u8 value)
+{
+	if (alps_command_mode_set_addr(psmouse, addr))
+		return -1;
+	return __alps_command_mode_write_reg(psmouse, value);
+}
+
+static int alps_enter_command_mode(struct psmouse *psmouse,
+				   unsigned char *resp)
+{
+	unsigned char param[4];
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+
+	if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_WRAP) ||
+	    ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_WRAP) ||
+	    ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_WRAP) ||
+	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
+		psmouse_err(psmouse, "failed to enter command mode\n");
+		return -1;
+	}
+
+	if (param[0] != 0x88 && param[1] != 0x07) {
+		psmouse_dbg(psmouse,
+			    "unknown response while entering command mode: %2.2x %2.2x %2.2x\n",
+			    param[0], param[1], param[2]);
+		return -1;
+	}
+
+	if (resp)
+		*resp = param[2];
+	return 0;
+}
+
+static inline int alps_exit_command_mode(struct psmouse *psmouse)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSTREAM))
+		return -1;
+	return 0;
+}
+
 static const struct alps_model_info *alps_get_model(struct psmouse *psmouse, int *version)
 {
 	struct ps2dev *ps2dev = &psmouse->ps2dev;
 	static const unsigned char rates[] = { 0, 10, 20, 40, 60, 80, 100, 200 };
 	unsigned char param[4];
+	const struct alps_model_info *model = NULL;
 	int i;
 
 	/*
@@ -428,12 +809,41 @@
 		*version = (param[0] << 8) | (param[1] << 4) | i;
 	}
 
-	for (i = 0; i < ARRAY_SIZE(alps_model_data); i++)
+	for (i = 0; i < ARRAY_SIZE(alps_model_data); i++) {
 		if (!memcmp(param, alps_model_data[i].signature,
-			    sizeof(alps_model_data[i].signature)))
-			return alps_model_data + i;
+			    sizeof(alps_model_data[i].signature))) {
+			model = alps_model_data + i;
+			break;
+		}
+	}
 
-	return NULL;
+	if (model && model->proto_version > ALPS_PROTO_V2) {
+		/*
+		 * Need to check command mode response to identify
+		 * model
+		 */
+		model = NULL;
+		if (alps_enter_command_mode(psmouse, param)) {
+			psmouse_warn(psmouse,
+				     "touchpad failed to enter command mode\n");
+		} else {
+			for (i = 0; i < ARRAY_SIZE(alps_model_data); i++) {
+				if (alps_model_data[i].proto_version > ALPS_PROTO_V2 &&
+				    alps_model_data[i].command_mode_resp == param[0]) {
+					model = alps_model_data + i;
+					break;
+				}
+			}
+			alps_exit_command_mode(psmouse);
+
+			if (!model)
+				psmouse_dbg(psmouse,
+					    "Unknown command mode response %2.2x\n",
+					    param[0]);
+		}
+	}
+
+	return model;
 }
 
 /*
@@ -441,7 +851,7 @@
  * subsequent commands. It looks like glidepad is behind stickpointer,
  * I'd thought it would be other way around...
  */
-static int alps_passthrough_mode(struct psmouse *psmouse, bool enable)
+static int alps_passthrough_mode_v2(struct psmouse *psmouse, bool enable)
 {
 	struct ps2dev *ps2dev = &psmouse->ps2dev;
 	int cmd = enable ? PSMOUSE_CMD_SETSCALE21 : PSMOUSE_CMD_SETSCALE11;
@@ -458,7 +868,7 @@
 	return 0;
 }
 
-static int alps_absolute_mode(struct psmouse *psmouse)
+static int alps_absolute_mode_v1_v2(struct psmouse *psmouse)
 {
 	struct ps2dev *ps2dev = &psmouse->ps2dev;
 
@@ -533,13 +943,13 @@
 	bool poll_failed;
 
 	if (priv->i->flags & ALPS_PASS)
-		alps_passthrough_mode(psmouse, true);
+		alps_passthrough_mode_v2(psmouse, true);
 
 	poll_failed = ps2_command(&psmouse->ps2dev, buf,
 				  PSMOUSE_CMD_POLL | (psmouse->pktsize << 8)) < 0;
 
 	if (priv->i->flags & ALPS_PASS)
-		alps_passthrough_mode(psmouse, false);
+		alps_passthrough_mode_v2(psmouse, false);
 
 	if (poll_failed || (buf[0] & priv->i->mask0) != priv->i->byte0)
 		return -1;
@@ -556,13 +966,13 @@
 	return 0;
 }
 
-static int alps_hw_init(struct psmouse *psmouse)
+static int alps_hw_init_v1_v2(struct psmouse *psmouse)
 {
 	struct alps_data *priv = psmouse->private;
 	const struct alps_model_info *model = priv->i;
 
 	if ((model->flags & ALPS_PASS) &&
-	    alps_passthrough_mode(psmouse, true)) {
+	    alps_passthrough_mode_v2(psmouse, true)) {
 		return -1;
 	}
 
@@ -571,13 +981,13 @@
 		return -1;
 	}
 
-	if (alps_absolute_mode(psmouse)) {
+	if (alps_absolute_mode_v1_v2(psmouse)) {
 		psmouse_err(psmouse, "Failed to enable absolute mode\n");
 		return -1;
 	}
 
 	if ((model->flags & ALPS_PASS) &&
-	    alps_passthrough_mode(psmouse, false)) {
+	    alps_passthrough_mode_v2(psmouse, false)) {
 		return -1;
 	}
 
@@ -590,6 +1000,297 @@
 	return 0;
 }
 
+/*
+ * Enable or disable passthrough mode to the trackstick. Must be in
+ * command mode when calling this function.
+ */
+static int alps_passthrough_mode_v3(struct psmouse *psmouse, bool enable)
+{
+	int reg_val;
+
+	reg_val = alps_command_mode_read_reg(psmouse, 0x0008);
+	if (reg_val == -1)
+		return -1;
+
+	if (enable)
+		reg_val |= 0x01;
+	else
+		reg_val &= ~0x01;
+
+	if (__alps_command_mode_write_reg(psmouse, reg_val))
+		return -1;
+
+	return 0;
+}
+
+/* Must be in command mode when calling this function */
+static int alps_absolute_mode_v3(struct psmouse *psmouse)
+{
+	int reg_val;
+
+	reg_val = alps_command_mode_read_reg(psmouse, 0x0004);
+	if (reg_val == -1)
+		return -1;
+
+	reg_val |= 0x06;
+	if (__alps_command_mode_write_reg(psmouse, reg_val))
+		return -1;
+
+	return 0;
+}
+
+static int alps_hw_init_v3(struct psmouse *psmouse)
+{
+	struct alps_data *priv = psmouse->private;
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	int reg_val;
+	unsigned char param[4];
+
+	priv->nibble_commands = alps_v3_nibble_commands;
+	priv->addr_command = PSMOUSE_CMD_RESET_WRAP;
+
+	if (alps_enter_command_mode(psmouse, NULL))
+		goto error;
+
+	/* Check for trackstick */
+	reg_val = alps_command_mode_read_reg(psmouse, 0x0008);
+	if (reg_val == -1)
+		goto error;
+	if (reg_val & 0x80) {
+		if (alps_passthrough_mode_v3(psmouse, true))
+			goto error;
+		if (alps_exit_command_mode(psmouse))
+			goto error;
+
+		/*
+		 * E7 report for the trackstick
+		 *
+		 * There have been reports of failures to seem to trace back
+		 * to the above trackstick check failing. When these occur
+		 * this E7 report fails, so when that happens we continue
+		 * with the assumption that there isn't a trackstick after
+		 * all.
+		 */
+		param[0] = 0x64;
+		if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) ||
+		    ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) ||
+		    ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE21) ||
+		    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
+			psmouse_warn(psmouse, "trackstick E7 report failed\n");
+		} else {
+			psmouse_dbg(psmouse,
+				    "trackstick E7 report: %2.2x %2.2x %2.2x\n",
+				    param[0], param[1], param[2]);
+
+			/*
+			 * Not sure what this does, but it is absolutely
+			 * essential. Without it, the touchpad does not
+			 * work at all and the trackstick just emits normal
+			 * PS/2 packets.
+			 */
+			if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) ||
+			    ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) ||
+			    ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) ||
+			    alps_command_mode_send_nibble(psmouse, 0x9) ||
+			    alps_command_mode_send_nibble(psmouse, 0x4)) {
+				psmouse_err(psmouse,
+					    "Error sending magic E6 sequence\n");
+				goto error_passthrough;
+			}
+		}
+
+		if (alps_enter_command_mode(psmouse, NULL))
+			goto error_passthrough;
+		if (alps_passthrough_mode_v3(psmouse, false))
+			goto error;
+	}
+
+	if (alps_absolute_mode_v3(psmouse)) {
+		psmouse_err(psmouse, "Failed to enter absolute mode\n");
+		goto error;
+	}
+
+	reg_val = alps_command_mode_read_reg(psmouse, 0x0006);
+	if (reg_val == -1)
+		goto error;
+	if (__alps_command_mode_write_reg(psmouse, reg_val | 0x01))
+		goto error;
+
+	reg_val = alps_command_mode_read_reg(psmouse, 0x0007);
+	if (reg_val == -1)
+		goto error;
+	if (__alps_command_mode_write_reg(psmouse, reg_val | 0x01))
+		goto error;
+
+	if (alps_command_mode_read_reg(psmouse, 0x0144) == -1)
+		goto error;
+	if (__alps_command_mode_write_reg(psmouse, 0x04))
+		goto error;
+
+	if (alps_command_mode_read_reg(psmouse, 0x0159) == -1)
+		goto error;
+	if (__alps_command_mode_write_reg(psmouse, 0x03))
+		goto error;
+
+	if (alps_command_mode_read_reg(psmouse, 0x0163) == -1)
+		goto error;
+	if (alps_command_mode_write_reg(psmouse, 0x0163, 0x03))
+		goto error;
+
+	if (alps_command_mode_read_reg(psmouse, 0x0162) == -1)
+		goto error;
+	if (alps_command_mode_write_reg(psmouse, 0x0162, 0x04))
+		goto error;
+
+	/*
+	 * This ensures the trackstick packets are in the format
+	 * supported by this driver. If bit 1 isn't set the packet
+	 * format is different.
+	 */
+	if (alps_command_mode_write_reg(psmouse, 0x0008, 0x82))
+		goto error;
+
+	alps_exit_command_mode(psmouse);
+
+	/* Set rate and enable data reporting */
+	param[0] = 0x64;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE) ||
+	    ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE)) {
+		psmouse_err(psmouse, "Failed to enable data reporting\n");
+		return -1;
+	}
+
+	return 0;
+
+error_passthrough:
+	/* Something failed while in passthrough mode, so try to get out */
+	if (!alps_enter_command_mode(psmouse, NULL))
+		alps_passthrough_mode_v3(psmouse, false);
+error:
+	/*
+	 * Leaving the touchpad in command mode will essentially render
+	 * it unusable until the machine reboots, so exit it here just
+	 * to be safe
+	 */
+	alps_exit_command_mode(psmouse);
+	return -1;
+}
+
+/* Must be in command mode when calling this function */
+static int alps_absolute_mode_v4(struct psmouse *psmouse)
+{
+	int reg_val;
+
+	reg_val = alps_command_mode_read_reg(psmouse, 0x0004);
+	if (reg_val == -1)
+		return -1;
+
+	reg_val |= 0x02;
+	if (__alps_command_mode_write_reg(psmouse, reg_val))
+		return -1;
+
+	return 0;
+}
+
+static int alps_hw_init_v4(struct psmouse *psmouse)
+{
+	struct alps_data *priv = psmouse->private;
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	unsigned char param[4];
+
+	priv->nibble_commands = alps_v4_nibble_commands;
+	priv->addr_command = PSMOUSE_CMD_DISABLE;
+
+	if (alps_enter_command_mode(psmouse, NULL))
+		goto error;
+
+	if (alps_absolute_mode_v4(psmouse)) {
+		psmouse_err(psmouse, "Failed to enter absolute mode\n");
+		goto error;
+	}
+
+	if (alps_command_mode_write_reg(psmouse, 0x0007, 0x8c))
+		goto error;
+
+	if (alps_command_mode_write_reg(psmouse, 0x0149, 0x03))
+		goto error;
+
+	if (alps_command_mode_write_reg(psmouse, 0x0160, 0x03))
+		goto error;
+
+	if (alps_command_mode_write_reg(psmouse, 0x017f, 0x15))
+		goto error;
+
+	if (alps_command_mode_write_reg(psmouse, 0x0151, 0x01))
+		goto error;
+
+	if (alps_command_mode_write_reg(psmouse, 0x0168, 0x03))
+		goto error;
+
+	if (alps_command_mode_write_reg(psmouse, 0x014a, 0x03))
+		goto error;
+
+	if (alps_command_mode_write_reg(psmouse, 0x0161, 0x03))
+		goto error;
+
+	alps_exit_command_mode(psmouse);
+
+	/*
+	 * This sequence changes the output from a 9-byte to an
+	 * 8-byte format. All the same data seems to be present,
+	 * just in a more compact format.
+	 */
+	param[0] = 0xc8;
+	param[1] = 0x64;
+	param[2] = 0x50;
+	if (ps2_command(ps2dev, &param[0], PSMOUSE_CMD_SETRATE) ||
+	    ps2_command(ps2dev, &param[1], PSMOUSE_CMD_SETRATE) ||
+	    ps2_command(ps2dev, &param[2], PSMOUSE_CMD_SETRATE) ||
+	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETID))
+		return -1;
+
+	/* Set rate and enable data reporting */
+	param[0] = 0x64;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE) ||
+	    ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE)) {
+		psmouse_err(psmouse, "Failed to enable data reporting\n");
+		return -1;
+	}
+
+	return 0;
+
+error:
+	/*
+	 * Leaving the touchpad in command mode will essentially render
+	 * it unusable until the machine reboots, so exit it here just
+	 * to be safe
+	 */
+	alps_exit_command_mode(psmouse);
+	return -1;
+}
+
+static int alps_hw_init(struct psmouse *psmouse)
+{
+	struct alps_data *priv = psmouse->private;
+	const struct alps_model_info *model = priv->i;
+	int ret = -1;
+
+	switch (model->proto_version) {
+	case ALPS_PROTO_V1:
+	case ALPS_PROTO_V2:
+		ret = alps_hw_init_v1_v2(psmouse);
+		break;
+	case ALPS_PROTO_V3:
+		ret = alps_hw_init_v3(psmouse);
+		break;
+	case ALPS_PROTO_V4:
+		ret = alps_hw_init_v4(psmouse);
+		break;
+	}
+
+	return ret;
+}
+
 static int alps_reconnect(struct psmouse *psmouse)
 {
 	const struct alps_model_info *model;
@@ -630,6 +1331,8 @@
 
 	psmouse->private = priv;
 
+	psmouse_reset(psmouse);
+
 	model = alps_get_model(psmouse, &version);
 	if (!model)
 		goto init_fail;
@@ -657,8 +1360,20 @@
 		BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_RIGHT);
 
 	dev1->evbit[BIT_WORD(EV_ABS)] |= BIT_MASK(EV_ABS);
-	input_set_abs_params(dev1, ABS_X, 0, 1023, 0, 0);
-	input_set_abs_params(dev1, ABS_Y, 0, 767, 0, 0);
+
+	switch (model->proto_version) {
+	case ALPS_PROTO_V1:
+	case ALPS_PROTO_V2:
+		input_set_abs_params(dev1, ABS_X, 0, 1023, 0, 0);
+		input_set_abs_params(dev1, ABS_Y, 0, 767, 0, 0);
+		break;
+	case ALPS_PROTO_V3:
+	case ALPS_PROTO_V4:
+		input_set_abs_params(dev1, ABS_X, 0, 2000, 0, 0);
+		input_set_abs_params(dev1, ABS_Y, 0, 1400, 0, 0);
+		break;
+	}
+
 	input_set_abs_params(dev1, ABS_PRESSURE, 0, 127, 0, 0);
 
 	if (model->flags & ALPS_WHEEL) {
@@ -701,7 +1416,7 @@
 	psmouse->poll = alps_poll;
 	psmouse->disconnect = alps_disconnect;
 	psmouse->reconnect = alps_reconnect;
-	psmouse->pktsize = 6;
+	psmouse->pktsize = model->proto_version == ALPS_PROTO_V4 ? 8 : 6;
 
 	/* We are having trouble resyncing ALPS touchpads so disable it for now */
 	psmouse->resync_time = 0;