path: root/Documentation/input
diff options
authorHenrik Rydberg <rydberg@euromail.se>2010-12-06 10:05:43 +0100
committerHenrik Rydberg <rydberg@euromail.se>2010-12-16 10:42:29 +0100
commite42a98b520bb22535687ead3120e80edc268279a (patch)
treecd8bfdc35552a3d3911928b0d1a6600e85793264 /Documentation/input
parentc5f4dec1ceb6ab773bbbefbe64a7c990c7d6b17f (diff)
input: mt: Add hovering distance axis
Touch devices capable of hovering, i.e., fingers detected a distance from the surface, are not supported by the current input MT protocol. This patch adds ABS_MT_DISTANCE, which may be used to indicate the distance between the contact and the surface. Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Diffstat (limited to 'Documentation/input')
1 files changed, 8 insertions, 1 deletions
diff --git a/Documentation/input/multi-touch-protocol.txt b/Documentation/input/multi-touch-protocol.txt
index bdcba154b83e..07215fa0c588 100644
--- a/Documentation/input/multi-touch-protocol.txt
+++ b/Documentation/input/multi-touch-protocol.txt
@@ -161,7 +161,8 @@ against the glass. The inner region will increase, and in general, the
ratio ABS_MT_TOUCH_MAJOR / ABS_MT_WIDTH_MAJOR, which is always smaller than
unity, is related to the contact pressure. For pressure-based devices,
ABS_MT_PRESSURE may be used to provide the pressure on the contact area
+instead. Devices capable of contact hovering can use ABS_MT_DISTANCE to
+indicate the distance between the contact and the surface.
In addition to the MAJOR parameters, the oval shape of the contact can be
described by adding the MINOR parameters, such that MAJOR and MINOR are the
@@ -213,6 +214,12 @@ The pressure, in arbitrary units, on the contact area. May be used instead
of TOUCH and WIDTH for pressure-based devices or any device with a spatial
signal intensity distribution.
+The distance, in surface units, between the contact and the surface. Zero
+distance means the contact is touching the surface. A positive number means
+the contact is hovering above the surface.
The orientation of the ellipse. The value should describe a signed quarter