[PATCH 1/2] Input: MT - Make slot cleanup callable outsidemt_sync_frame()

[Henrik Rydberg]

Some semi-mt drivers use the slots in a manual way, but may still
want to call parts of the frame synchronization logic. This patch
makes input_mt_drop_unused callable from those drivers.

Signed-off-by: Henrik Rydberg <rydberg@xxxxxxxxxxx>
---
 drivers/input/input-mt.c | 38 +++++++++++++++++++++++++++-----------
 include/linux/input/mt.h |  1 +
 2 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index 1b7f4d4..a22094d 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -235,6 +235,31 @@ void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count)
 EXPORT_SYMBOL(input_mt_report_pointer_emulation);
 
 /**
+ * input_mt_drop_unused() - Inactivate slots not seen in this frame
+ * @dev: input device with allocated MT slots
+ *
+ * Lift all slots not seen since the last call to this function.
+ */
+void input_mt_drop_unused(struct input_dev *dev)
+{
+	struct input_mt *mt = dev->mt;
+	struct input_mt_slot *s;
+
+	if (!mt)
+		return;
+
+	for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
+		if (s->frame == mt->frame)
+			continue;
+		input_mt_slot(dev, s - mt->slots);
+		input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
+	}
+
+	mt->frame++;
+}
+EXPORT_SYMBOL(input_mt_drop_unused);
+
+/**
  * input_mt_sync_frame() - synchronize mt frame
  * @dev: input device with allocated MT slots
  *
@@ -245,23 +270,14 @@ EXPORT_SYMBOL(input_mt_report_pointer_emulation);
 void input_mt_sync_frame(struct input_dev *dev)
 {
 	struct input_mt *mt = dev->mt;
-	struct input_mt_slot *s;
 
 	if (!mt)
 		return;
 
-	if (mt->flags & INPUT_MT_DROP_UNUSED) {
-		for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
-			if (s->frame == mt->frame)
-				continue;
-			input_mt_slot(dev, s - mt->slots);
-			input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
-		}
-	}
+	if (mt->flags & INPUT_MT_DROP_UNUSED)
+		input_mt_drop_unused(dev);
 
 	input_mt_report_pointer_emulation(dev, (mt->flags & INPUT_MT_POINTER));
-
-	mt->frame++;
 }
 EXPORT_SYMBOL(input_mt_sync_frame);
 
diff --git a/include/linux/input/mt.h b/include/linux/input/mt.h
index cc5cca7..5766be1 100644
--- a/include/linux/input/mt.h
+++ b/include/linux/input/mt.h
@@ -98,6 +98,7 @@ void input_mt_report_slot_state(struct input_dev *dev,
 
 void input_mt_report_finger_count(struct input_dev *dev, int count);
 void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count);
+void input_mt_drop_unused(struct input_dev *dev);
 
 void input_mt_sync_frame(struct input_dev *dev);
 
-- 
1.8.1.3