[PATCH] hid-magicmouse: Correct parsing of large X and Y motions.

[Michael Poole <mdpoole@troilus.org>]

The X and Y values have two more significant bits in the same byte
that contains click status.  Include these in the reported value.
Thanks to Iain Hibbert of NetBSD for pointing this out.

Signed-off-by: Michael Poole <mdpoole@troilus.org>
---
 drivers/hid/hid-magicmouse.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-magicmouse.c b/drivers/hid/hid-magicmouse.c
index 0b89c1c..7cdda23 100644
--- a/drivers/hid/hid-magicmouse.c
+++ b/drivers/hid/hid-magicmouse.c
@@ -267,8 +267,8 @@ static int magicmouse_raw_event(struct hid_device *hdev,
 		 * to have the current touch information before
 		 * generating a click event.
 		 */
-		x = (signed char)data[1];
-		y = (signed char)data[2];
+		x = (int)(((data[3] & 0x0c) << 28) | (data[1] << 22)) >> 22;
+		y = (int)(((data[3] & 0x30) << 26) | (data[2] << 22)) >> 22;
 		clicks = data[3];
 		break;
 	case 0x20: /* Theoretically battery status (0-100), but I have
-- 
1.7.1