Input: byd - add BYD PS/2 touchpad driver

Driver for the BYD BTP10463 touchpad, found in PC Specialist `Lafite'
laptops. This patch sends the magic command sequence which causes the
touchpad to stream intellimouse-style packets.

Gestures are detected inside the touchpad, and exposed as special
values in the Z component of each packet - absolute coordinates are
not supported, even in the Windows driver. At present, this supports
two-finger vertical and horizontal scrolling, and provides the
framework to expose the other gestures it can recognize.

Signed-off-by: Chris Diamand <chris@diamand.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/psmouse-base.c

@@ -37,6 +37,7 @@
 #include "cypress_ps2.h"
 #include "focaltech.h"
 #include "vmmouse.h"
+#include "byd.h"
 
 #define DRIVER_DESC	"PS/2 mouse driver"
 
@@ -841,6 +842,15 @@ static const struct psmouse_protocol psmouse_protocols[] = {
 		.detect		= vmmouse_detect,
 		.init		= vmmouse_init,
 	},
+#endif
+#ifdef CONFIG_MOUSE_PS2_BYD
+	{
+		.type		= PSMOUSE_BYD,
+		.name		= "BydPS/2",
+		.alias		= "byd",
+		.detect		= byd_detect,
+		.init		= byd_init,
+	},
 #endif
 	{
 		.type		= PSMOUSE_AUTO,
@@ -1105,6 +1115,10 @@ static int psmouse_extensions(struct psmouse *psmouse,
 		if (psmouse_try_protocol(psmouse, PSMOUSE_TOUCHKIT_PS2,
 					 &max_proto, set_properties, true))
 			return PSMOUSE_TOUCHKIT_PS2;
+
+		if (psmouse_try_protocol(psmouse, PSMOUSE_BYD,
+					 &max_proto, set_properties, true))
+			return PSMOUSE_BYD;
 	}
 
 	/*