Input: update input_mt_report_pointer_emulation to support hovering
For devices that are incapable of reporting per-contact distance and can
only report ABS_DISTANCE, just distance is not enough for upper layers of
OS to determine whether contact is leaving the area or if it is continuing
hovering, we need BTN_TOOL_FINGER for that:
Contact State
Inactive Hovering Active
(far away) (inside hover area) (touching surface)
BTN_TOUCH 0 0 1
BTN_TOOL_FINGER 0 1 1
ABS_DISTANCE N/A 1 0
Signed-off-by: KT Liao <kt.liao@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index 54fce56..a1bbec9 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -218,8 +218,23 @@
}
input_event(dev, EV_KEY, BTN_TOUCH, count > 0);
- if (use_count)
+
+ if (use_count) {
+ if (count == 0 &&
+ !test_bit(ABS_MT_DISTANCE, dev->absbit) &&
+ test_bit(ABS_DISTANCE, dev->absbit) &&
+ input_abs_get_val(dev, ABS_DISTANCE) != 0) {
+ /*
+ * Force reporting BTN_TOOL_FINGER for devices that
+ * only report general hover (and not per-contact
+ * distance) when contact is in proximity but not
+ * on the surface.
+ */
+ count = 1;
+ }
+
input_mt_report_finger_count(dev, count);
+ }
if (oldest) {
int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);