Complete rewrite of the Elantech clickpads v4 packet parser in order to

support "click-and-drag".

This implements a simple filter to keep track of a moving finger on the
clickpad.  For the moment wsmouse(4) and wscons(4) are still unaware of
multitouch events and pms(4) has to do the translation, but this is a
small steps in this direction.

All the good work has been done by Ulf Brosziewski.

1 files changed, 89 insertions, 59 deletions

diff --git a/sys/dev/pckbc/pms.c b/sys/dev/pckbc/pms.c
index ed0b5acc6d2..fdffa119241 100644
--- a/sys/dev/pckbc/pms.c
+++ b/sys/dev/pckbc/pms.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: pms.c,v 1.56 2015/01/15 01:19:28 jsg Exp $ */
+/* $OpenBSD: pms.c,v 1.57 2015/02/09 04:05:25 mpi Exp $ */
 /* $NetBSD: psm.c,v 1.11 2000/06/05 22:20:57 sommerfeld Exp $ */
 
 /*-
@@ -142,8 +142,15 @@ struct elantech_softc {
 	struct {
 		unsigned int x;
 		unsigned int y;
+		unsigned int z;
 	} mt[ELANTECH_MAX_FINGERS];
-	int fingers[ELANTECH_MAX_FINGERS];
+	int mt_slots;
+	int mt_count;
+	int mt_filter;
+	int mt_lastid;
+	int mt_lastcount;
+	int mt_buttons;
+
 	int width;
 
 	u_char parity[256];
@@ -314,6 +321,7 @@ int	elantech_set_absolute_mode_v2(struct pms_softc *);
 int	elantech_set_absolute_mode_v3(struct pms_softc *);
 int	elantech_set_absolute_mode_v4(struct pms_softc *);
 
+void	elantech_send_mt_input(struct pms_softc *, int);
 
 struct cfattach pms_ca = {
 	sizeof(struct pms_softc), pmsprobe, pmsattach, NULL,
@@ -2258,75 +2266,66 @@ void
 pms_proc_elantech_v4(struct pms_softc *sc)
 {
 	struct elantech_softc *elantech = sc->elantech;
-	int z, delta_x1 = 0, delta_x2 = 0, delta_y1 = 0, delta_y2 = 0;
-	int i, weight, finger, fingers = 0, id, sid;
+	int n, id, slots, weight, dx, dy;
 
 	switch (sc->packet[3] & 0x1f) {
 	case ELANTECH_V4_PKT_STATUS:
-		fingers = sc->packet[1] & 0x1f;
-		for (i = 0; i < ELANTECH_MAX_FINGERS; i++) {
-			finger = ((fingers & (1 << i)) != 0);
-			if (elantech->fingers[i] && !finger)
-				/* notify that we lifted */
-				elantech_send_input(sc, elantech->mt[i].x,
-				    elantech->mt[i].y, 0, 0);
-
-			elantech->fingers[i] = finger;
-		}
+		if (elantech->mt_slots == 0)
+			elantech->mt_lastid = -1;
+		slots = sc->packet[1] & 0x1f;
+		if (slots == 0 && elantech->mt_lastid > -1)
+			/* Notify that we lifted. */
+			elantech_send_input(sc,
+			    elantech->mt[elantech->mt_lastid].x,
+			    elantech->mt[elantech->mt_lastid].y, 0, 0);
+
+		elantech->mt_filter = elantech->mt_slots = slots;
+
+		for (elantech->mt_count = 0; slots != 0; slots >>= 1)
+			elantech->mt_count += (1 & slots);
 
 		break;
 
 	case ELANTECH_V4_PKT_HEAD:
 		id = ((sc->packet[3] & 0xe0) >> 5) - 1;
-		if (id < 0)
-			return;
-
-		for (i = 0; i < ELANTECH_MAX_FINGERS; i++)
-			if (elantech->fingers[i])
-				fingers++;
-
-		elantech->mt[id].x = ((sc->packet[1] & 0x0f) << 8) |
-		    sc->packet[2];
-		elantech->mt[id].y = (((sc->packet[4] & 0x0f) << 8) |
-		    sc->packet[5]);
-		z = (sc->packet[1] & 0xf0) | ((sc->packet[4] & 0xf0) >> 4);
-
-		elantech_send_input(sc, elantech->mt[id].x, elantech->mt[id].y,
-		    z, fingers);
-
+		if (id > -1 && id < ELANTECH_MAX_FINGERS) {
+			elantech->mt[id].x =
+			    ((sc->packet[1] & 0x0f) << 8) | sc->packet[2];
+			elantech->mt[id].y =
+			    ((sc->packet[4] & 0x0f) << 8) | sc->packet[5];
+			elantech->mt[id].z =
+			    (sc->packet[1] & 0xf0)
+			    | ((sc->packet[4] & 0xf0) >> 4);
+
+			if (elantech->mt_filter & (1 << id)) {
+				elantech_send_mt_input(sc, id);
+				elantech->mt_filter = (1 << id);
+			}
+		}
 		break;
 
 	case ELANTECH_V4_PKT_MOTION:
-		id = ((sc->packet[0] & 0xe0) >> 5) - 1;
-		if (id < 0)
-			return;
-
-		sid = ((sc->packet[3] & 0xe0) >> 5) - 1;
 		weight = (sc->packet[0] & 0x10) ? ELANTECH_V4_WEIGHT_VALUE : 1;
-
-		delta_x1 = (signed char)sc->packet[1];
-		delta_y1 = (signed char)sc->packet[2];
-		delta_x2 = (signed char)sc->packet[4];
-		delta_y2 = (signed char)sc->packet[5];
-
-		elantech->mt[id].x += delta_x1 * weight;
-		elantech->mt[id].y -= delta_y1 * weight;
-
-		for (i = 0; i < ELANTECH_MAX_FINGERS; i++)
-			if (elantech->fingers[i])
-				fingers++;
-
-		elantech_send_input(sc, elantech->mt[id].x, elantech->mt[id].y,
-		    1, fingers);
-
-		if (sid >= 0) {
-			elantech->mt[sid].x += delta_x2 * weight;
-			elantech->mt[sid].y -= delta_y2 * weight;
-			/* XXX: can only send one finger of input */
-			/*
-			elantech_send_input(sc, elantech->mt[sid].x,
-			    elantech->mt[sid].y, 1, fingers);
-			*/
+		for (n = 0; n < 6; n += 3) {
+			id = ((sc->packet[n] & 0xe0) >> 5) - 1;
+			if (id < 0 || id >= ELANTECH_MAX_FINGERS)
+				continue;
+			dx = weight * (signed char)sc->packet[n + 1];
+			dy = weight * (signed char)sc->packet[n + 2];
+			elantech->mt[id].x += dx;
+			elantech->mt[id].y += dy;
+			elantech->mt[id].z = 1;
+			if (elantech->mt_filter & (1 << id)) {
+				if ((dx | dy)
+				    || elantech->mt_count !=
+				    elantech->mt_lastcount
+				    || (sc->packet[0] & 3) !=
+				    elantech->mt_buttons)
+					elantech_send_mt_input(sc, id);
+
+				elantech->mt_filter = (dx | dy) ?
+				    (1 << id) : elantech->mt_slots;
+			}
 		}
 
 		break;
@@ -2339,6 +2338,37 @@ pms_proc_elantech_v4(struct pms_softc *sc)
 }
 
 void
+elantech_send_mt_input(struct pms_softc *sc, int id)
+{
+	struct elantech_softc *elantech = sc->elantech;
+
+	if (id != elantech->mt_lastid) {
+		/* Correct for compatibility mode, but not useful yet: */
+		elantech->old_x = elantech->mt[id].x;
+		elantech->old_y = elantech->mt[id].y;
+		/*
+		 * To avoid a jump of the cursor, simulate a change of the
+		 * number of touches (without producing tapping gestures
+		 * accidentally). It should suffice to do that only if
+		 * mt_count hasn't changed, but we cannot rely on the
+		 * synaptics driver, which alters its finger counts when
+		 * handling click-and-drag actions (see HandleTapProcessing
+		 * and ComputeDeltas in synaptics.c).
+		 */
+		if (elantech->mt_lastid > -1)
+			elantech_send_input(sc,
+			    elantech->mt[id].x, elantech->mt[id].y,
+			    elantech->mt[id].z, ELANTECH_MAX_FINGERS);
+		elantech->mt_lastid = id;
+	}
+	elantech->mt_lastcount = elantech->mt_count;
+	elantech->mt_buttons = sc->packet[0] & 3;
+	elantech_send_input(sc,
+	    elantech->mt[id].x, elantech->mt[id].y,
+	    elantech->mt[id].z, elantech->mt_count);
+}
+
+void
 elantech_send_input(struct pms_softc *sc, int x, int y, int z, int w)
 {
 	struct elantech_softc *elantech = sc->elantech;