From: Markus Armbruster <armbru@redhat.com>
Date: Tue, 8 Jul 2008 17:15:58 -0400
Subject: [xen] pvfb: frontend mouse wheel support
Message-id: m3tzf0axgx.fsf@crossbow.pond.sub.org
O-Subject: [PATCH RHEL-5.3] bz 446235: Xen PVFB frontend mouse wheel support
Bugzilla: 446235
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
RH-Acked-by: Bill Burns <bburns@redhat.com>

Mouse wheel support straightforwardly ported from the driver in
XenSource's 2.6.18.  Changesets:
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/354
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/439
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/449

Fully backward compatible, but of course it needs the backend patched
to do anything useful (bug 250401).

Please ACK.

diff --git a/drivers/xen/fbfront/xenkbd.c b/drivers/xen/fbfront/xenkbd.c
index ad04c54..cb409ed 100644
--- a/drivers/xen/fbfront/xenkbd.c
+++ b/drivers/xen/fbfront/xenkbd.c
@@ -61,6 +61,9 @@ static irqreturn_t input_handler(int rq, void *dev_id, struct pt_regs *regs)
 
 		switch (event->type) {
 		case XENKBD_TYPE_MOTION:
+			if (event->motion.rel_z)
+				input_report_rel(info->dev, REL_WHEEL,
+						 -event->motion.rel_z);
 			input_report_rel(info->dev, REL_X, event->motion.rel_x);
 			input_report_rel(info->dev, REL_Y, event->motion.rel_y);
 			break;
@@ -68,6 +71,9 @@ static irqreturn_t input_handler(int rq, void *dev_id, struct pt_regs *regs)
 			input_report_key(info->dev, event->key.keycode, event->key.pressed);
 			break;
 		case XENKBD_TYPE_POS:
+			if (event->pos.rel_z)
+				input_report_rel(info->dev, REL_WHEEL,
+						 -event->pos.rel_z);
 			input_report_abs(info->dev, ABS_X, event->pos.abs_x);
 			input_report_abs(info->dev, ABS_Y, event->pos.abs_y);
 			break;
@@ -109,7 +115,7 @@ int __devinit xenkbd_probe(struct xenbus_device *dev,
 	input_dev->keybit[LONG(BTN_MOUSE)]
 		= BIT(BTN_LEFT) | BIT(BTN_MIDDLE) | BIT(BTN_RIGHT);
 	/* TODO additional buttons */
-	input_dev->relbit[0] = BIT(REL_X) | BIT(REL_Y);
+	input_dev->relbit[0] = BIT(REL_X) | BIT(REL_Y) | BIT(REL_WHEEL);
 
 	/* FIXME not sure this is quite right */
 	for (i = 0; i < 256; i++)
diff --git a/include/xen/interface/io/kbdif.h b/include/xen/interface/io/kbdif.h
index be8c915..e9160c3 100644
--- a/include/xen/interface/io/kbdif.h
+++ b/include/xen/interface/io/kbdif.h
@@ -38,6 +38,7 @@ struct xenkbd_motion
 	__u8 type;         /* XENKBD_TYPE_MOTION */
 	__s32 rel_x;       /* relative X motion */
 	__s32 rel_y;       /* relative Y motion */
+	__s32 rel_z;       /* relative Z motion (wheel) */
 };
 
 struct xenkbd_key
@@ -52,6 +53,7 @@ struct xenkbd_position
 	__u8 type;         /* XENKBD_TYPE_POS */
 	__s32 abs_x;       /* absolute X position (in FB pixels) */
 	__s32 abs_y;       /* absolute Y position (in FB pixels) */
+	__s32 rel_z;       /* relative Z motion (wheel) */
 };
 
 #define XENKBD_IN_EVENT_SIZE 40