| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Mon, 5 Sep 2011 16:47:40 +0800
From: Daniel Kurtz <djkurtz@...omium.org>
To: JJ Ding <jj_ding@....com.tw>
Cc: linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
Seth Forshee <seth.forshee@...onical.com>,
Dmitry Torokhov <dmitry.torokhov@...il.com>,
Aaron Huang <aaron_huang@....com.tw>,
Tom Lin <tom_lin@....com.tw>,
Éric Piel <E.A.B.Piel@...elft.nl>,
Chase Douglas <chase.douglas@...onical.com>,
Henrik Rydberg <rydberg@...omail.se>,
Alessandro Rubini <rubini@...l.unipv.it>
Subject: Re: [PATCH v5 7/8] Input: elantech - add v3 hardware support
Hi JJ,
On Mon, Sep 5, 2011 at 4:39 PM, Daniel Kurtz <djkurtz@...omium.org> wrote:
> Hi JJ,
>
> On Mon, Sep 5, 2011 at 3:10 PM, JJ Ding <jj_ding@....com.tw> wrote:
>> Hi Daniel,
>>
>> On Mon, 5 Sep 2011 12:35:28 +0800, Daniel Kurtz <djkurtz@...omium.org> wrote:
>>> Hi JJ,
>>>
>>> On Mon, Sep 5, 2011 at 10:16 AM, JJ Ding <jj_ding@....com.tw> wrote:
>>> > diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
>>> > index 2ae7c49..c4ceefd 100644
>>> > --- a/drivers/input/mouse/elantech.c
>>> > +++ b/drivers/input/mouse/elantech.c
>>> > @@ -108,6 +108,16 @@ static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
>>> > rc = -1;
>>> > }
>>> > break;
>>> > +
>>> > + case 3:
>>> > + if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
>>> > + elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
>>> > + elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
>>> > + elantech_ps2_command(psmouse, NULL, reg) ||
>>> > + elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
>>> > + rc = -1;
>>> > + }
>>> > + break;
>>> > }
>>> >
>>> > if (rc)
>>> > @@ -154,6 +164,18 @@ static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
>>> > rc = -1;
>>> > }
>>> > break;
>>> > +
>>> > + case 3:
>>> > + if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
>>> > + elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
>>> > + elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
>>> > + elantech_ps2_command(psmouse, NULL, reg) ||
>>> > + elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
>>> > + elantech_ps2_command(psmouse, NULL, val) ||
>>> > + elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
>>> > + rc = -1;
>>> > + }
>>> > + break;
>>> > }
>>> >
>>> > if (rc)
>>> > @@ -350,6 +372,84 @@ static void elantech_report_absolute_v2(struct psmouse *psmouse)
>>> > input_sync(dev);
>>> > }
>>> >
>>> > +/*
>>> > + * Interpret complete data packets and report absolute mode input events for
>>> > + * hardware version 3. (12 byte packets for two fingers)
>>> > + */
>>> > +static void elantech_report_absolute_v3(struct psmouse *psmouse,
>>> > + int packet_type)
>>> > +{
>>> > + struct input_dev *dev = psmouse->dev;
>>> > + struct elantech_data *etd = psmouse->private;
>>> > + unsigned char *packet = psmouse->packet;
>>> > + unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
>>> > + unsigned int width = 0, pres = 0;
>>> > +
>>> > + /* byte 0: n1 n0 . . . . R L */
>>> > + fingers = (packet[0] & 0xc0) >> 6;
>>> > +
>>> > + switch (fingers) {
>>> > + case 3:
>>> > + case 1:
>>> > + /*
>>> > + * byte 1: . . . . x11 x10 x9 x8
>>> > + * byte 2: x7 x6 x5 x4 x4 x2 x1 x0
>>> > + */
>>> > + x1 = ((packet[1] & 0x0f) << 8) | packet[2];
>>> > + /*
>>> > + * byte 4: . . . . y11 y10 y9 y8
>>> > + * byte 5: y7 y6 y5 y4 y3 y2 y1 y0
>>> > + */
>>> > + y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
>>> > + break;
>>> > +
>>> > + case 2:
>>> > + if (packet_type == PACKET_V3_HEAD) {
>>> > + /*
>>> > + * byte 1: . . . . ax11 ax10 ax9 ax8
>>> > + * byte 2: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
>>> > + */
>>> > + etd->prev_x = ((packet[1] & 0x0f) << 8) | packet[2];
>>> > + /*
>>> > + * byte 4: . . . . ay11 ay10 ay9 ay8
>>> > + * byte 5: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0
>>> > + */
>>> > + etd->prev_y = etd->y_max -
>>> > + (((packet[4] & 0x0f) << 8) | packet[5]);
>>> > + /*
>>> > + * wait for next packet
>>> > + */
>>> > + return;
>>> > + }
>>> > +
>>> > + /* packet_type == PACKET_V3_TAIL */
>>> > + x1 = etd->prev_x;
>>> > + y1 = etd->prev_y;
>>> > + x2 = ((packet[1] & 0x0f) << 8) | packet[2];
>>> > + y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
>>> > + break;
>>> > + }
>>> > +
>>> > + pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
>>> > + width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
>>> > +
>>> > + input_report_key(dev, BTN_TOUCH, fingers != 0);
>>> > + if (fingers != 0) {
>>> > + input_report_abs(dev, ABS_X, x1);
>>> > + input_report_abs(dev, ABS_Y, y1);
>>> > + }
>>> > + elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
>>>
>>> Originally, v3 was using semi-mt, which reported corner coordinates of
>>> a box containing at least two of the N touches on the touchpad. I
>>> thought this was due to hardware limitation.
>>>
>>> If the hardware really can report true positions for (up to) 3
>>> contacts, then using pure MT-B is a good approach. This driver still
>>> seems to mix semi-mt and MT-B together a bit.
>>>
>>> Can you report all three contacts in their own slots, 0, 1 and 2,
>>> instead of just reoprting two of them with 0,1?
>>>
>>> Also, when reporting the 'legacy single touch' coordinate (ABS_X,
>>> ABS_Y), please use:
>>> input_mt_report_pointer_emulation(), instead of always reporting the
>>> last (x1,y1). Otherwise the single touch point will bounce back and
>>> forth between 1st and 3rd touch.
>>
>> v3 can only track the true positions of two fingers. With 3 finger
>> touch, it reports the lowest value of x and the biggest value of y,
>> among the three fingers. v3 changed the protocol so it could report
>> 2-finger touch data w/o reduced resolution and improved the hardware to
>> truly track 2 fingers independently, otherwise it's pretty much the same
>> as v2.
>
>
> If I read this code correctly, it looks like in the 3-finger case,
> (x1,y1) as reported in the (ABS_X, ABS_Y), and in the call to
> elantech_report_semi_mt_data() will bounce back and forth between the
> 1st finger and 3rd finger ("lowest value of x and the biggest value of
> y"). Won't this be very confusing for userspace (i.e.
> xf86-input=synaptics)?
Oh, never mind. Sorry for the confusion. I guess in the 3-finger
case, you only get "3-finger" packets containing the single ("lowest
value of x and the biggest value of y") bounding box coordinate, not
V3_HEAD/V3_TAIL packets.
I believe this shouldn't be reported as MT-B slot 0, though. If
anything, perhaps you should use MT-B slot 2 for this coordinate?
It's not really the third finger, but at least it won't be considered
a continuation of the motion of the first finger.
I guess you really have no choice but to use it as the (ABS_X, ABS_Y)
coordinate.
-Dan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists