From: Aristeu Rozanski <arozansk@redhat.com>
Date: Fri, 14 Sep 2007 09:05:49 -0400
Subject: [input] psmouse: add support to 'cortps' protocol
Message-id: 20070914130549.GB23728@redhat.com
O-Subject: [RHEL5.2 PATCH] psmouse: add support to 'cortps' protocol
Bugzilla: 248759

https://bugzilla.redhat.com/show_bug.cgi?id=248759

This patch adds support to 'cortps' protocol which supports Cortron PS/2
Trackballs. These trackballs have 4 buttons and the fourth button is
reported in a non standard way. They also don't have any detection
protocol, so you have to manually set the protocol writting the
'protocol' sysfs file:
	echo -n "cortps" > /sys/devices/platform/i8042/serio$NUM/protocol

Upstream: aea6a46122a0ce65a831fd93cac6d2084ac666f9

Tested by Chris Williams

Acked-by: Pete Zaitcev <zaitcev@redhat.com>

diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 07b0604..4300ac6 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -185,6 +185,15 @@ static psmouse_ret_t psmouse_process_byte(struct psmouse *psmouse, struct pt_reg
 	}
 
 /*
+ * Cortron PS2 Trackball reports SIDE button on the 4th bit of the first
+ * byte.
+ */
+	if (psmouse->type == PSMOUSE_CORTRON) {
+		input_report_key(dev, BTN_SIDE, (packet[0] >> 3) & 1);
+		packet[0] |= 0x08;
+	}
+
+/*
  * Generic PS/2 Mouse
  */
 
@@ -544,6 +553,20 @@ static int ps2bare_detect(struct psmouse *psmouse, int set_properties)
 	return 0;
 }
 
+/*
+ * Cortron PS/2 protocol detection. There's no special way to detect it, so it
+ * must be forced by sysfs protocol writing.
+ */
+static int cortron_detect(struct psmouse *psmouse, int set_properties)
+{
+	if (set_properties) {
+		psmouse->vendor = "Cortron";
+		psmouse->name = "PS/2 Trackball";
+		set_bit(BTN_SIDE, psmouse->dev->keybit);
+	}
+
+	return 0;
+}
 
 /*
  * psmouse_extensions() probes for any extensions to the basic PS/2 protocol
@@ -718,6 +741,12 @@ static struct psmouse_protocol psmouse_protocols[] = {
 		.alias		= "trackpoint",
 		.detect		= trackpoint_detect,
 	},
+ 	{
+		.type		= PSMOUSE_CORTRON,
+		.name		= "CortronPS/2",
+		.alias		= "cortps",
+		.detect		= cortron_detect,
+	},
 	{
 		.type		= PSMOUSE_AUTO,
 		.name		= "auto",
diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
index 4d9107f..2e191dd 100644
--- a/drivers/input/mouse/psmouse.h
+++ b/drivers/input/mouse/psmouse.h
@@ -86,6 +86,7 @@ enum psmouse_type {
 	PSMOUSE_ALPS,
 	PSMOUSE_LIFEBOOK,
 	PSMOUSE_TRACKPOINT,
+	PSMOUSE_CORTRON,
 	PSMOUSE_AUTO		/* This one should always be last */
 };