+ /*
+ * 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 ...
+ */
+