Input: psmouse - support for the FocalTech PS/2 protocol extensions

Most of the protocol for these touchpads has been reverse engineered. This
commit adds a basic multitouch-capable driver.

A lot of the protocol is still unknown. Especially, we don't know how to
identify the device yet apart from the PNP ID.

The previous workaround for these devices has been left in place in case
the driver is not compiled into the kernel or in case some other device
with the same PNP ID is not recognized by the driver yet still has the same
problems with the device probing code.
Signed-off-by: Mathias Gottschlag <mgottschlag@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/Kconfig

@@ -146,6 +146,16 @@ config MOUSE_PS2_OLPC
 
 	  If unsure, say N.
 
+config MOUSE_PS2_FOCALTECH
+	bool "FocalTech PS/2 mouse protocol extension" if EXPERT
+	default y
+	depends on MOUSE_PS2
+	help
+	  Say Y here if you have a FocalTech PS/2 TouchPad connected to
+	  your system.
+
+	  If unsure, say Y.
+
 config MOUSE_SERIAL
 	tristate "Serial mouse"
 	select SERIO

drivers/input/mouse/focaltech.h

@@ -2,6 +2,7 @@
  * Focaltech TouchPad PS/2 mouse driver
  *
  * Copyright (c) 2014 Red Hat Inc.
+ * Copyright (c) 2014 Mathias Gottschlag <mgottschlag@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,5 +19,6 @@
 
 int focaltech_detect(struct psmouse *psmouse, bool set_properties);
 int focaltech_init(struct psmouse *psmouse);
+bool focaltech_supported(void);
 
 #endif

drivers/input/mouse/psmouse-base.c

@@ -725,16 +725,19 @@ static int psmouse_extensions(struct psmouse *psmouse,
 
 /* Always check for focaltech, this is safe as it uses pnp-id matching */
 	if (psmouse_do_detect(focaltech_detect, psmouse, set_properties) == 0) {
-		if (!set_properties || focaltech_init(psmouse) == 0) {
-			/*
-			 * Not supported yet, use bare protocol.
-			 * Note that we need to also restrict
-			 * psmouse_max_proto so that psmouse_initialize()
-			 * does not try to reset rate and resolution,
-			 * because even that upsets the device.
-			 */
-			psmouse_max_proto = PSMOUSE_PS2;
-			return PSMOUSE_PS2;
+		if (max_proto > PSMOUSE_IMEX) {
+			if (!set_properties || focaltech_init(psmouse) == 0) {
+				if (focaltech_supported())
+					return PSMOUSE_FOCALTECH;
+				/*
+				 * Note that we need to also restrict
+				 * psmouse_max_proto so that psmouse_initialize()
+				 * does not try to reset rate and resolution,
+				 * because even that upsets the device.
+				 */
+				psmouse_max_proto = PSMOUSE_PS2;
+				return PSMOUSE_PS2;
+			}
 		}
 	}
 
@@ -1063,6 +1066,15 @@ static const struct psmouse_protocol psmouse_protocols[] = {
 		.alias		= "cortps",
 		.detect		= cortron_detect,
 	},
+#ifdef CONFIG_MOUSE_PS2_FOCALTECH
+	{
+		.type		= PSMOUSE_FOCALTECH,
+		.name		= "FocalTechPS/2",
+		.alias		= "focaltech",
+		.detect		= focaltech_detect,
+		.init		= focaltech_init,
+	},
+#endif
 	{
 		.type		= PSMOUSE_AUTO,
 		.name		= "auto",

drivers/input/mouse/psmouse.h

@@ -96,6 +96,7 @@ enum psmouse_type {
 	PSMOUSE_FSP,
 	PSMOUSE_SYNAPTICS_RELATIVE,
 	PSMOUSE_CYPRESS,
+	PSMOUSE_FOCALTECH,
 	PSMOUSE_AUTO		/* This one should always be last */
 };