Commit 7894f21b authored by JJ Ding's avatar JJ Ding Committed by Dmitry Torokhov

Input: elantech - packet checking for v2 hardware

For v2 hardware, there is no real parity check, but we can still check
some constant bits for data integrity.

Also rename elantech_check_parity_v1 to elantech_packet_check_v1 to make
these packet checking function names consistent.
Signed-off-by: default avatarJJ Ding <jj_ding@emc.com.tw>
Acked-by: default avatarDaniel Kurtz <djkurtz@chromium.org>
Acked-by: default avatarÉric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 8a360d09
...@@ -350,7 +350,7 @@ static void elantech_report_absolute_v2(struct psmouse *psmouse) ...@@ -350,7 +350,7 @@ static void elantech_report_absolute_v2(struct psmouse *psmouse)
input_sync(dev); input_sync(dev);
} }
static int elantech_check_parity_v1(struct psmouse *psmouse) static int elantech_packet_check_v1(struct psmouse *psmouse)
{ {
struct elantech_data *etd = psmouse->private; struct elantech_data *etd = psmouse->private;
unsigned char *packet = psmouse->packet; unsigned char *packet = psmouse->packet;
...@@ -374,6 +374,34 @@ static int elantech_check_parity_v1(struct psmouse *psmouse) ...@@ -374,6 +374,34 @@ static int elantech_check_parity_v1(struct psmouse *psmouse)
etd->parity[packet[3]] == p3; etd->parity[packet[3]] == p3;
} }
static int elantech_packet_check_v2(struct psmouse *psmouse)
{
struct elantech_data *etd = psmouse->private;
unsigned char *packet = psmouse->packet;
/*
* V2 hardware has two flavors. Older ones that do not report pressure,
* and newer ones that reports pressure and width. With newer ones, all
* packets (1, 2, 3 finger touch) have the same constant bits. With
* older ones, 1/3 finger touch packets and 2 finger touch packets
* have different constant bits.
* With all three cases, if the constant bits are not exactly what I
* expected, I consider them invalid.
*/
if (etd->reports_pressure)
return (packet[0] & 0x0c) == 0x04 &&
(packet[3] & 0x0f) == 0x02;
if ((packet[0] & 0xc0) == 0x80)
return (packet[0] & 0x0c) == 0x0c &&
(packet[3] & 0x0e) == 0x08;
return (packet[0] & 0x3c) == 0x3c &&
(packet[1] & 0xf0) == 0x00 &&
(packet[3] & 0x3e) == 0x38 &&
(packet[4] & 0xf0) == 0x00;
}
/* /*
* Process byte stream from mouse and handle complete packets * Process byte stream from mouse and handle complete packets
*/ */
...@@ -389,14 +417,16 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse) ...@@ -389,14 +417,16 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
switch (etd->hw_version) { switch (etd->hw_version) {
case 1: case 1:
if (etd->paritycheck && !elantech_check_parity_v1(psmouse)) if (etd->paritycheck && !elantech_packet_check_v1(psmouse))
return PSMOUSE_BAD_DATA; return PSMOUSE_BAD_DATA;
elantech_report_absolute_v1(psmouse); elantech_report_absolute_v1(psmouse);
break; break;
case 2: case 2:
/* We don't know how to check parity in protocol v2 */ if (etd->paritycheck && !elantech_packet_check_v2(psmouse))
return PSMOUSE_BAD_DATA;
elantech_report_absolute_v2(psmouse); elantech_report_absolute_v2(psmouse);
break; break;
} }
...@@ -795,8 +825,7 @@ int elantech_init(struct psmouse *psmouse) ...@@ -795,8 +825,7 @@ int elantech_init(struct psmouse *psmouse)
etd->hw_version = 2; etd->hw_version = 2;
/* For now show extra debug information */ /* For now show extra debug information */
etd->debug = 1; etd->debug = 1;
/* Don't know how to do parity checking for version 2 */ etd->paritycheck = 1;
etd->paritycheck = 0;
if (etd->fw_version >= 0x020800) if (etd->fw_version >= 0x020800)
etd->reports_pressure = true; etd->reports_pressure = true;
......
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