Based on the protocol description, and the source code of the
Dell/Ubuntu driver, the two additional types of data checking for the
6-byte protocol are added. Technically, this is not parity checking, but
to avoid too much change, "paritycheck" is kept to talk about the checks.
In addition, as in the Dell/Ubuntu driver, instead of dropping all the
bytes when an error is detected, just drop the first byte, so that
it's possible to re-synchronize quickly.
Signed-off-by: Éric Piel <eric.piel@xxxxxxxxxxxxxxxx>
---
drivers/input/mouse/elantech.c | 61 +++++++++++++++++++++++++++++++++++++--
1 files changed, 57 insertions(+), 4 deletions(-)
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index badb2ea..8f0a1ee 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -348,6 +348,57 @@ static int elantech_check_parity_v1(struct psmouse *psmouse)
etd->parity[packet[3]] == p3;
}
+static int elantech_check_parity_ef113(struct psmouse *psmouse)
+{
+ unsigned char *packet = psmouse->packet;
+
+ /* Consistency checks as in the Dell/Ubuntu driver */
+ return !((((packet[0] & 0x3c) != 0x3c) && ((packet[0] & 0xc0) != 0x80)) ||
+ (((packet[0] & 0x0c) != 0x0c) && ((packet[0] & 0xc0) == 0x80)) ||
+ (((packet[0] & 0xc0) != 0x80) && ((packet[1] & 0xf0) != 0x00)) ||
+ (((packet[3] & 0x3e) != 0x38) && ((packet[0] & 0xc0) != 0x80)) ||
+ (((packet[3] & 0x0e) != 0x08) && ((packet[0] & 0xc0) == 0x80)) ||
+ (((packet[0] & 0xc0) != 0x80) && ((packet[4] & 0xf0) != 0x00)));
+}
+
+static int elantech_check_parity_const(struct psmouse *psmouse)
+{
+ unsigned char *packet = psmouse->packet;
+
+ /* Some bits which are constant in the 6 packets */
+ return (((packet[0] & 0x0c) == 0x04) && ((packet[3] & 0x0f) == 0x02));
+}
+
+/*
+ * Returns 0 if an error is detected in the packets.
+ */
+static int elantech_check_parity(struct psmouse *psmouse)
+{
+ struct elantech_data *etd = psmouse->private;
+
+ switch (etd->paritycheck) {
+ case ETP_FULL_PC:
+ return elantech_check_parity_v1(psmouse);
+ case ETP_EF113_CHECK:
+ return elantech_check_parity_ef113(psmouse);
+ case ETP_CONST_CHECK:
+ return elantech_check_parity_const(psmouse);
+ case ETP_NOT_CHECK:
+ default:
+ return 1;
+ }
+}
+
+static void elantech_shift_packets(struct psmouse *psmouse)
+{
+ unsigned char *packet = psmouse->packet;
+ int i;
+
+ for (i = 0; i < (psmouse->pktsize - 1); i++)
+ packet[i] = packet[i + 1];
+ psmouse->pktcnt--;
+}
+
/*
* Process byte stream from mouse and handle complete packets
*/
@@ -361,16 +412,18 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
if (etd->debug > 1)
elantech_packet_dump(psmouse->packet, psmouse->pktsize);
+ if (!elantech_check_parity(psmouse)) {
+ /* Try to re-synchronize */
+ elantech_shift_packets(psmouse);
+ return PSMOUSE_GOOD_DATA;
+ }
+
switch (etd->hw_version) {
case 1:
- if (etd->paritycheck && !elantech_check_parity_v1(psmouse))
- return PSMOUSE_BAD_DATA;
-
elantech_report_absolute_v1(psmouse);
break;
case 2:
- /* We don't know how to check parity in protocol v2 */
elantech_report_absolute_v2(psmouse);
break;
}
--
1.7.5.1
--
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