Input: add support for Cypress PS/2 Trackpads

This driver, submitted on behalf of Cypress Semiconductor Corporation and
additional contributors, provides support for the Cypress PS/2 Trackpad.

Original code contributed by Dudley Du (Cypress Semiconductor Corporation),
modified by Kamal Mostafa and Kyle Fazzari.

BugLink: http://launchpad.net/bugs/978807

Signed-off-by: Dudley Du <dudl@cypress.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kyle Fazzari <git@status.e4ward.com>
Signed-off-by: Mario Limonciello <mario_limonciello@dell.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Herton Krzesinski <herton.krzesinski@canonical.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Reviewed-by: Dudley Du <dudl@cypress.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 22fe254..cff065f 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -34,6 +34,7 @@
 #include "touchkit_ps2.h"
 #include "elantech.h"
 #include "sentelic.h"
+#include "cypress_ps2.h"
 
 #define DRIVER_DESC	"PS/2 mouse driver"
 
@@ -759,6 +760,28 @@
 	}
 
 /*
+ * Try Cypress Trackpad.
+ * Must try it before Finger Sensing Pad because Finger Sensing Pad probe
+ * upsets some modules of Cypress Trackpads.
+ */
+	if (max_proto > PSMOUSE_IMEX &&
+			cypress_detect(psmouse, set_properties) == 0) {
+		if (cypress_supported()) {
+			if (cypress_init(psmouse) == 0)
+				return PSMOUSE_CYPRESS;
+
+			/*
+			 * Finger Sensing Pad probe upsets some modules of
+			 * Cypress Trackpad, must avoid Finger Sensing Pad
+			 * probe if Cypress Trackpad device detected.
+			 */
+			return PSMOUSE_PS2;
+		}
+
+		max_proto = PSMOUSE_IMEX;
+	}
+
+/*
  * Try ALPS TouchPad
  */
 	if (max_proto > PSMOUSE_IMEX) {
@@ -896,6 +919,15 @@
 		.alias		= "thinkps",
 		.detect		= thinking_detect,
 	},
+#ifdef CONFIG_MOUSE_PS2_CYPRESS
+	{
+		.type		= PSMOUSE_CYPRESS,
+		.name		= "CyPS/2",
+		.alias		= "cypress",
+		.detect		= cypress_detect,
+		.init		= cypress_init,
+	},
+#endif
 	{
 		.type		= PSMOUSE_GENPS,
 		.name		= "GenPS/2",