From c736a757129a1a2c1e8e11d18daa9742f7ec0d35 Mon Sep 17 00:00:00 2001
From: Oleksandr Tymoshenko <gonzo@FreeBSD.org>
Date: Sat, 8 Oct 2016 17:59:53 +0000
Subject: [PATCH] Implement EVDEV_FLAG_MT_AUTOREL flag (autorelease
 touchpoints)

Automaticaly release (send ABS_MT_TRACKING_ID = -1) MT-slots
that has not been listed in current MT protocol type B report.

Slot is counted as listed if corresponding ABS_MT_SLOT event
has been sent regardless of other MT events.

Events are sent on SYN_REPORT event.

Submitted by:	Vladimir Kondratiev <wulf@cicgroup.ru>
---
 sys/dev/evdev/evdev.c         |  8 +++++---
 sys/dev/evdev/evdev.h         |  2 ++
 sys/dev/evdev/evdev_mt.c      | 23 +++++++++++++++++++----
 sys/dev/evdev/evdev_private.h |  1 +
 4 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/sys/dev/evdev/evdev.c b/sys/dev/evdev/evdev.c
index 7da8eb14182c..63e04966fec9 100644
--- a/sys/dev/evdev/evdev.c
+++ b/sys/dev/evdev/evdev.c
@@ -686,6 +686,8 @@ evdev_sparse_event(struct evdev_dev *evdev, uint16_t type, uint16_t code,
 
 	case EV_SYN:
 		if (code == SYN_REPORT) {
+			/* Count empty reports as well as non empty */
+			evdev->ev_report_count++;
 			/* Skip empty reports */
 			if (!evdev->ev_report_opened)
 				return (EV_SKIP_EVENT);
@@ -722,10 +724,7 @@ evdev_propagate_event(struct evdev_dev *evdev, uint16_t type, uint16_t code,
 		EVDEV_CLIENT_UNLOCKQ(client);
 	}
 
-	/* Update counters */
 	evdev->ev_event_count++;
-	if (type == EV_SYN && code == SYN_REPORT)
-		evdev->ev_report_count++;
 }
 
 void
@@ -765,6 +764,9 @@ evdev_push_event(struct evdev_dev *evdev, uint16_t type, uint16_t code,
 	if (evdev->ev_lock_type == EV_LOCK_INTERNAL)
 		EVDEV_LOCK(evdev);
 	evdev_modify_event(evdev, type, code, &value);
+	if (type == EV_SYN && code == SYN_REPORT &&
+	     bit_test(evdev->ev_flags, EVDEV_FLAG_MT_AUTOREL))
+		evdev_send_mt_autorel(evdev);
 	if (type == EV_SYN && code == SYN_REPORT && evdev->ev_report_opened &&
 	    bit_test(evdev->ev_flags, EVDEV_FLAG_MT_STCOMPAT))
 		evdev_send_mt_compat(evdev);
diff --git a/sys/dev/evdev/evdev.h b/sys/dev/evdev/evdev.h
index 2c4aeee1abcf..7287e739e832 100644
--- a/sys/dev/evdev/evdev.h
+++ b/sys/dev/evdev/evdev.h
@@ -70,6 +70,8 @@ extern int evdev_rcpt_mask;
 #define	EVDEV_FLAG_SOFTREPEAT	0x00	/* use evdev to repeat keys */
 #define	EVDEV_FLAG_MT_STCOMPAT	0x01	/* autogenerate ST-compatible events
 					 * for MT protocol type B reports */
+#define	EVDEV_FLAG_MT_AUTOREL	0x02	/* Autorelease MT-slots not listed in
+					 * current MT protocol type B report */
 #define	EVDEV_FLAG_MAX		0x1F
 #define	EVDEV_FLAG_CNT		(EVDEV_FLAG_MAX + 1)
 
diff --git a/sys/dev/evdev/evdev_mt.c b/sys/dev/evdev/evdev_mt.c
index ef36006ddaf6..82f36d8478e2 100644
--- a/sys/dev/evdev/evdev_mt.c
+++ b/sys/dev/evdev/evdev_mt.c
@@ -112,6 +112,7 @@ void
 evdev_set_last_mt_slot(struct evdev_dev *evdev, int32_t slot)
 {
 
+	evdev->ev_mt->ev_mt_slots[slot].ev_report = evdev->ev_report_count;
 	evdev->ev_mt->ev_mt_last_reported_slot = slot;
 }
 
@@ -128,10 +129,6 @@ evdev_set_mt_value(struct evdev_dev *evdev, int32_t slot, int16_t code,
     int32_t value)
 {
 
-	if (code == ABS_MT_TRACKING_ID && value == -1)
-		evdev->ev_mt->ev_mt_slots[slot].ev_report =
-		    evdev->ev_report_count;
-
 	evdev->ev_mt->ev_mt_slots[slot].ev_mt_states[ABS_MT_INDEX(code)] =
 	    value;
 }
@@ -275,3 +272,21 @@ evdev_push_mt_compat(struct evdev_dev *evdev)
 	if (evdev->ev_lock_type == EV_LOCK_INTERNAL)
 		EVDEV_UNLOCK(evdev);
 }
+
+void
+evdev_send_mt_autorel(struct evdev_dev *evdev)
+{
+	int32_t slot;
+
+	EVDEV_LOCK_ASSERT(evdev);
+
+	for (slot = 0; slot <= MAXIMAL_MT_SLOT(evdev); slot++) {
+		if (evdev->ev_mt->ev_mt_slots[slot].ev_report !=
+		    evdev->ev_report_count &&
+		    evdev_get_mt_value(evdev, slot, ABS_MT_TRACKING_ID) != -1){
+			evdev_send_event(evdev, EV_ABS, ABS_MT_SLOT, slot);
+			evdev_send_event(evdev, EV_ABS, ABS_MT_TRACKING_ID,
+			    -1);
+		}
+	}
+}
diff --git a/sys/dev/evdev/evdev_private.h b/sys/dev/evdev/evdev_private.h
index 4305c5959587..b3de1bf0fa40 100644
--- a/sys/dev/evdev/evdev_private.h
+++ b/sys/dev/evdev/evdev_private.h
@@ -192,6 +192,7 @@ void evdev_set_last_mt_slot(struct evdev_dev *, int32_t);
 int32_t evdev_get_mt_value(struct evdev_dev *, int32_t, int16_t);
 void evdev_set_mt_value(struct evdev_dev *, int32_t, int16_t, int32_t);
 void evdev_send_mt_compat(struct evdev_dev *);
+void evdev_send_mt_autorel(struct evdev_dev *);
 
 /* Utility functions: */
 void evdev_client_dumpqueue(struct evdev_client *);