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path: root/drivers/input/mouse/elantech.c
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Diffstat (limited to 'drivers/input/mouse/elantech.c')
-rw-r--r--drivers/input/mouse/elantech.c44
1 files changed, 40 insertions, 4 deletions
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index 57b2637e153a..8551dcaf24db 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -672,6 +672,7 @@ static int elantech_packet_check_v2(struct psmouse *psmouse)
*/
static int elantech_packet_check_v3(struct psmouse *psmouse)
{
+ struct elantech_data *etd = psmouse->private;
const u8 debounce_packet[] = { 0xc4, 0xff, 0xff, 0x02, 0xff, 0xff };
unsigned char *packet = psmouse->packet;
@@ -682,19 +683,48 @@ static int elantech_packet_check_v3(struct psmouse *psmouse)
if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
return PACKET_DEBOUNCE;
- if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
- return PACKET_V3_HEAD;
+ /*
+ * If the hardware flag 'crc_enabled' is set the packets have
+ * different signatures.
+ */
+ if (etd->crc_enabled) {
+ if ((packet[3] & 0x09) == 0x08)
+ return PACKET_V3_HEAD;
+
+ if ((packet[3] & 0x09) == 0x09)
+ return PACKET_V3_TAIL;
+ } else {
+ if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
+ return PACKET_V3_HEAD;
- if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
- return PACKET_V3_TAIL;
+ if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
+ return PACKET_V3_TAIL;
+ }
return PACKET_UNKNOWN;
}
static int elantech_packet_check_v4(struct psmouse *psmouse)
{
+ struct elantech_data *etd = psmouse->private;
unsigned char *packet = psmouse->packet;
unsigned char packet_type = packet[3] & 0x03;
+ bool sanity_check;
+
+ /*
+ * Sanity check based on the constant bits of a packet.
+ * The constant bits change depending on the value of
+ * the hardware flag 'crc_enabled' but are the same for
+ * every packet, regardless of the type.
+ */
+ if (etd->crc_enabled)
+ sanity_check = ((packet[3] & 0x08) == 0x00);
+ else
+ sanity_check = ((packet[0] & 0x0c) == 0x04 &&
+ (packet[3] & 0x1c) == 0x10);
+
+ if (!sanity_check)
+ return PACKET_UNKNOWN;
switch (packet_type) {
case 0:
@@ -1313,6 +1343,12 @@ static int elantech_set_properties(struct elantech_data *etd)
etd->reports_pressure = true;
}
+ /*
+ * The signatures of v3 and v4 packets change depending on the
+ * value of this hardware flag.
+ */
+ etd->crc_enabled = ((etd->fw_version & 0x4000) == 0x4000);
+
return 0;
}