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: JJ Ding <jj_ding@emc.com.tw> Acked-by: Daniel Kurtz <djkurtz@chromium.org> Acked-by: Éric Piel <eric.piel@tremplin-utc.net> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
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1 changed files with 34 additions and 5 deletions
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@ -350,7 +350,7 @@ static void elantech_report_absolute_v2(struct psmouse *psmouse)
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input_sync(dev);
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}
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static int elantech_check_parity_v1(struct psmouse *psmouse)
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static int elantech_packet_check_v1(struct psmouse *psmouse)
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{
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struct elantech_data *etd = psmouse->private;
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unsigned char *packet = psmouse->packet;
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@ -374,6 +374,34 @@ static int elantech_check_parity_v1(struct psmouse *psmouse)
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etd->parity[packet[3]] == p3;
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}
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static int elantech_packet_check_v2(struct psmouse *psmouse)
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{
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struct elantech_data *etd = psmouse->private;
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unsigned char *packet = psmouse->packet;
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/*
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* V2 hardware has two flavors. Older ones that do not report pressure,
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* and newer ones that reports pressure and width. With newer ones, all
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* packets (1, 2, 3 finger touch) have the same constant bits. With
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* older ones, 1/3 finger touch packets and 2 finger touch packets
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* have different constant bits.
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* With all three cases, if the constant bits are not exactly what I
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* expected, I consider them invalid.
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*/
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if (etd->reports_pressure)
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return (packet[0] & 0x0c) == 0x04 &&
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(packet[3] & 0x0f) == 0x02;
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if ((packet[0] & 0xc0) == 0x80)
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return (packet[0] & 0x0c) == 0x0c &&
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(packet[3] & 0x0e) == 0x08;
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return (packet[0] & 0x3c) == 0x3c &&
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(packet[1] & 0xf0) == 0x00 &&
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(packet[3] & 0x3e) == 0x38 &&
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(packet[4] & 0xf0) == 0x00;
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}
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/*
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* Process byte stream from mouse and handle complete packets
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*/
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@ -389,14 +417,16 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
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switch (etd->hw_version) {
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case 1:
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if (etd->paritycheck && !elantech_check_parity_v1(psmouse))
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if (etd->paritycheck && !elantech_packet_check_v1(psmouse))
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return PSMOUSE_BAD_DATA;
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elantech_report_absolute_v1(psmouse);
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break;
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case 2:
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/* We don't know how to check parity in protocol v2 */
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if (etd->paritycheck && !elantech_packet_check_v2(psmouse))
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return PSMOUSE_BAD_DATA;
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elantech_report_absolute_v2(psmouse);
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break;
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}
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@ -795,8 +825,7 @@ int elantech_init(struct psmouse *psmouse)
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etd->hw_version = 2;
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/* For now show extra debug information */
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etd->debug = 1;
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/* Don't know how to do parity checking for version 2 */
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etd->paritycheck = 0;
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etd->paritycheck = 1;
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if (etd->fw_version >= 0x020800)
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etd->reports_pressure = true;
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