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authorHans de Goede <hdegoede@redhat.com>2014-12-18 09:54:50 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2014-12-18 10:01:28 -0800
commit27a560ba1d4f0a07a36e1de2cae839abe776e8f3 (patch)
treed36286806288d9ce2fdd2ac2399f3333a466db50 /drivers/input
parentd27eb7931c98a1ebfc9b2fcc48939846bcbfc804 (diff)
Input: alps - v7: document the v7 touchpad packet protocol
Add a table documenting where all the bits are in the v7 touchpad packets. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input')
-rw-r--r--drivers/input/mouse/alps.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index b48c6fb317ed..0faea6df228b 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -881,6 +881,34 @@ static void alps_get_finger_coordinate_v7(struct input_mt_pos *mt,
unsigned char *pkt,
unsigned char pkt_id)
{
+ /*
+ * packet-fmt b7 b6 b5 b4 b3 b2 b1 b0
+ * Byte0 TWO & MULTI L 1 R M 1 Y0-2 Y0-1 Y0-0
+ * Byte0 NEW L 1 X1-5 1 1 Y0-2 Y0-1 Y0-0
+ * Byte1 Y0-10 Y0-9 Y0-8 Y0-7 Y0-6 Y0-5 Y0-4 Y0-3
+ * Byte2 X0-11 1 X0-10 X0-9 X0-8 X0-7 X0-6 X0-5
+ * Byte3 X1-11 1 X0-4 X0-3 1 X0-2 X0-1 X0-0
+ * Byte4 TWO X1-10 TWO X1-9 X1-8 X1-7 X1-6 X1-5 X1-4
+ * Byte4 MULTI X1-10 TWO X1-9 X1-8 X1-7 X1-6 Y1-5 1
+ * Byte4 NEW X1-10 TWO X1-9 X1-8 X1-7 X1-6 0 0
+ * Byte5 TWO & NEW Y1-10 0 Y1-9 Y1-8 Y1-7 Y1-6 Y1-5 Y1-4
+ * Byte5 MULTI Y1-10 0 Y1-9 Y1-8 Y1-7 Y1-6 F-1 F-0
+ * L: Left button
+ * R / M: Non-clickpads: Right / Middle button
+ * Clickpads: When > 2 fingers are down, and some fingers
+ * are in the button area, then the 2 coordinates reported
+ * are for fingers outside the button area and these report
+ * extra fingers being present in the right / left button
+ * area. Note these fingers are not added to the F field!
+ * so if a TWO packet is received and R = 1 then there are
+ * 3 fingers down, etc.
+ * TWO: 1: Two touches present, byte 0/4/5 are in TWO fmt
+ * 0: If byte 4 bit 0 is 1, then byte 0/4/5 are in MULTI fmt
+ * otherwise byte 0 bit 4 must be set and byte 0/4/5 are
+ * in NEW fmt
+ * F: Number of fingers - 3, 0 means 3 fingers, 1 means 4 ...
+ */
+
mt[0].x = ((pkt[2] & 0x80) << 4);
mt[0].x |= ((pkt[2] & 0x3F) << 5);
mt[0].x |= ((pkt[3] & 0x30) >> 1);