From patchwork Wed Aug 24 05:38:21 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: JJ Ding X-Patchwork-Id: 1090852 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p7O5bDxn003240 for ; Wed, 24 Aug 2011 05:37:13 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751640Ab1HXFhC (ORCPT ); Wed, 24 Aug 2011 01:37:02 -0400 Received: from emcscan.emc.com.tw ([192.72.220.5]:46438 "EHLO emcscan.emc.com.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753183Ab1HXFgX (ORCPT ); Wed, 24 Aug 2011 01:36:23 -0400 Received: from unknown (HELO emc.com.tw) ([192.168.10.1]) by emcscan.emc.com.tw with ESMTP; 24 Aug 2011 13:36:22 +0800 Received: from localhost ([192.168.81.59]) by emc.com.tw (8.13.7+Sun/8.13.7) with ESMTP id p7O5aL6n005164; Wed, 24 Aug 2011 13:36:21 +0800 (CST) From: JJ Ding To: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Seth Forshee , Dmitry Torokhov , Aaron Huang , Tom Lin , =?UTF-8?q?=C3=89ric=20Piel?= , Daniel Kurtz , Chase Douglas , Henrik Rydberg , Alessandro Rubini , JJ Ding Subject: [PATCH v2 5/7] Input: elantech - packet checking for v2 hardware Date: Wed, 24 Aug 2011 13:38:21 +0800 Message-Id: <1314164303-30382-6-git-send-email-jj_ding@emc.com.tw> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1314164303-30382-1-git-send-email-jj_ding@emc.com.tw> References: <1314164303-30382-1-git-send-email-jj_ding@emc.com.tw> Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Wed, 24 Aug 2011 05:37:13 +0000 (UTC) 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 --- drivers/input/mouse/elantech.c | 39 ++++++++++++++++++++++++++++++++++----- 1 files changed, 34 insertions(+), 5 deletions(-) diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c index 282b8b6..008e8c2 100644 --- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -350,7 +350,7 @@ static void elantech_report_absolute_v2(struct psmouse *psmouse) 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; unsigned char *packet = psmouse->packet; @@ -374,6 +374,34 @@ static int elantech_check_parity_v1(struct psmouse *psmouse) 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 */ @@ -389,14 +417,16 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse) switch (etd->hw_version) { case 1: - if (etd->paritycheck && !elantech_check_parity_v1(psmouse)) + if (etd->paritycheck && !elantech_packet_check_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 */ + if (etd->paritycheck && !elantech_packet_check_v2(psmouse)) + return PSMOUSE_BAD_DATA; + elantech_report_absolute_v2(psmouse); break; } @@ -795,8 +825,7 @@ 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;