Messages in this thread Patch in this message | | | From | JJ Ding <> | Subject | [PATCH 3/6] Input: elantech - packet checking for v2 hardware | Date | Thu, 18 Aug 2011 09:57:06 +0800 |
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For v2 hardware, there is no real parity check, but we can still check some constant bits for data integrity.
Signed-off-by: JJ Ding <jj_ding@emc.com.tw> --- drivers/input/mouse/elantech.c | 26 +++++++++++++++++++++++--- 1 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c index cf41f23..032181c 100644 --- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -376,6 +376,25 @@ static int elantech_check_parity_v1(struct psmouse *psmouse) etd->parity[packet[3]] == p3; } +static int packet_simple_check_v2(struct psmouse *psmouse) +{ + struct elantech_data *etd = psmouse->private; + unsigned char *packet = psmouse->packet; + + 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 */ @@ -398,7 +417,9 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse) break; case 2: - /* We don't know how to check parity in protocol v2 */ + if (etd->paritycheck && !packet_simple_check_v2(psmouse)) + return PSMOUSE_BAD_DATA; + elantech_report_absolute_v2(psmouse); break; } @@ -799,8 +820,7 @@ int elantech_init(struct psmouse *psmouse) etd->hw_version = 2; /* For now show extra debug information */ etd->debug = 1; - /* Don't know how to do parity checking for version 2 */ - etd->paritycheck = 0; + etd->paritycheck = 1; if (etd->fw_version >= 0x020800) etd->reports_pressure = true; -- 1.7.4.1
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