Here we introduce logic in alps_identify to set the ALPS_DUALPOINT flag
for touchpad hardware responding to E7 report with 73 03 28, as is found
in the Dell Latitude E7470.
---
 drivers/input/mouse/alps.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 25d2cad..431bc26 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c

@@ -2776,6 +2776,7 @@ static int alps_identify(struct psmouse *psmouse, struct alps_data *priv)
 	const struct alps_protocol_info *protocol;
 	unsigned char e6[4], e7[4], ec[4];
 	int error;
+	int flags = 0;
 
 	/*
 	 * First try "E6 report".

@@ -2817,6 +2818,10 @@ static int alps_identify(struct psmouse *psmouse, struct alps_data *priv)
 		} else if (e7[0] == 0x73 && e7[1] == 0x03 &&
 			   e7[2] == 0x14 && ec[1] == 0x02) {
 			protocol = &alps_v8_protocol_data;
+		} else if (e7[0] == 0x73 && e7[1] == 0x03 &&
+			   e7[2] == 0x28 && ec[1] == 0x01) {
+			protocol = &alps_v8_protocol_data;
+			flags |= ALPS_DUALPOINT | ALPS_DUALPOINT_WITH_PRESSURE;
 		} else {
 			psmouse_dbg(psmouse,
 				    "Likely not an ALPS touchpad: E7=%3ph, EC=%3ph\n", e7, ec);

@@ -2830,6 +2835,7 @@ static int alps_identify(struct psmouse *psmouse, struct alps_data *priv)
 		error = alps_set_protocol(psmouse, priv, protocol);
 		if (error)
 			return error;
+		priv->flags |= flags;
 	}
 
 	return 0;