From: Peter Osterlund <petero2@telia.com>
To: Vojtech Pavlik <vojtech@suse.cz>
Cc: Kernel Mailing List <linux-kernel@vger.kernel.org>,
Joseph Fannin <jhf@rivenstone.net>,
Jens Taprogge <jens.taprogge@rwth-aachen.de>
Subject: Re: [PATCH] Synaptics TouchPad driver for 2.5.70
Date: 15 Jun 2003 17:47:57 +0200 [thread overview]
Message-ID: <m2of0zqr4i.fsf@telia.com> (raw)
In-Reply-To: <20030615142838.A3291@ucw.cz>
Vojtech Pavlik <vojtech@suse.cz> writes:
> On Sun, Jun 15, 2003 at 02:18:57PM +0200, Peter Osterlund wrote:
> >
> > - if (hw.w != priv->old_w) {
> > - input_event(dev, EV_MSC, MSC_GESTURE, hw.w);
> > - priv->old_w = hw.w;
> > - }
> > + /*
> > + * This will generate an event even if w is unchanged, but that is
> > + * exactly what we want, because user space drivers may depend on
> > + * this for gesture decoding.
> > + */
> > + input_event(dev, EV_MSC, MSC_GESTURE, hw.w);
>
> This assumption is not nice. It should instead rely on input_sync() /
> EV_SYN, SYN_REPORT events for complete packet decoding. Can you do
> something about that?
The X driver already relies on EV_SYN to decide when it should act on
the data from the kernel. The problem is that the packet stream is
used as a time base for gesture decoding, because the touchpad was
designed like that to make driver implementation simpler. From the
Synaptics manual:
(Specifically, the TouchPad begins sending packets when Z is 8
or more.) The TouchPad also begins sending packets whenever
any button is pressed or released. Once the TouchPad begins
transmitting, it continues to send packets for one second
after Z falls below 8 and the buttons stop changing. The
TouchPad does this partly to allow host software to use the
packet stream as a time base for gesture decoding, and also to
minimize the impact if the system occasionally drops a packet.
For example, if I press the left button, the X driver can not
immediately generate a left button down event, because maybe I will
press the right button real soon, in which case the middle mouse
button emulation will be activated and generate a middle button down
event. This and similar things are easy to implement by just counting
packets.
I guess it would be possible to rewrite the driver so that it doesn't
rely on the packet stream for timing, but it would make the driver
more complicated.
If I could generate only EV_SYN events from the kernel without the
EV_MSC events, that would of course be OK too, but I don't know if
that is possible.
The event parsing code int the X driver currently looks like this:
static Bool
SynapticsParseEventData(LocalDevicePtr local, SynapticsPrivatePtr priv,
struct SynapticsHwState *hw)
{
struct input_event ev;
while (SynapticsReadEvent(priv, &ev) == Success) {
switch (ev.type) {
case 0x00: /* SYN */
*hw = priv->hwState;
return Success;
case 0x01: /* KEY */
switch (ev.code) {
case 0x110: /* BTN_LEFT */
priv->hwState.left = (ev.value ? TRUE : FALSE);
break;
case 0x111: /* BTN_RIGHT */
priv->hwState.right = (ev.value ? TRUE : FALSE);
break;
case 0x115: /* BTN_FORWARD */
priv->hwState.up = (ev.value ? TRUE : FALSE);
break;
case 0x116: /* BTN_BACK */
priv->hwState.down = (ev.value ? TRUE : FALSE);
break;
}
break;
case 0x03: /* ABS */
switch (ev.code) {
case 0x00: /* ABS_X */
priv->hwState.x = ev.value;
break;
case 0x01: /* ABS_Y */
priv->hwState.y = ev.value;
break;
case 0x18: /* ABS_PRESSURE */
priv->hwState.z = ev.value;
break;
}
break;
case 0x04: /* MSC */
switch (ev.code) {
case 0x02: /* MSC_GESTURE */
priv->hwState.w = ev.value;
break;
}
break;
}
}
return !Success;
}
static Bool
SynapticsReadEvent(SynapticsPrivatePtr priv, struct input_event *ev)
{
int i, c;
unsigned char *pBuf, u;
for (i = 0; i < sizeof(struct input_event); i++) {
if ((c = XisbRead(priv->buffer)) < 0)
return !Success;
u = (unsigned char)c;
pBuf = (unsigned char *)ev;
pBuf[i] = u;
}
return Success;
}
--
Peter Osterlund - petero2@telia.com
http://w1.894.telia.com/~u89404340
next prev parent reply other threads:[~2003-06-15 15:34 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <m2smqhqk4k.fsf@p4.localdomain>
2003-06-11 15:02 ` [PATCH] Synaptics TouchPad driver for 2.5.70 Vojtech Pavlik
2003-06-11 18:16 ` Peter Osterlund
2003-06-11 18:26 ` Vojtech Pavlik
2003-06-11 18:29 ` AlberT
2003-06-11 18:34 ` Vojtech Pavlik
2003-06-11 21:23 ` Peter Osterlund
2003-06-12 2:48 ` Joseph Fannin
2003-06-12 2:54 ` CaT
2003-06-12 18:58 ` Peter Osterlund
2003-06-12 22:01 ` Peter Berg Larsen
2003-06-12 22:57 ` Vojtech Pavlik
2003-06-12 23:17 ` Peter Berg Larsen
2003-06-12 23:27 ` Vojtech Pavlik
2003-06-12 23:42 ` Peter Berg Larsen
2003-06-13 7:44 ` Vojtech Pavlik
2003-06-13 8:58 ` Peter Berg Larsen
2003-06-13 20:25 ` James Simmons
2003-06-13 20:38 ` Vojtech Pavlik
2003-06-13 20:51 ` James Simmons
2003-06-13 22:08 ` Vojtech Pavlik
2003-06-13 23:57 ` James Simmons
2003-06-14 8:55 ` Vojtech Pavlik
2003-06-16 21:28 ` James Simmons
2003-06-12 19:11 ` Peter Osterlund
2003-06-12 6:31 ` Vojtech Pavlik
2003-06-12 8:36 ` James H. Cloos Jr.
2003-06-15 21:42 ` [PATCH] Synaptics Client/Passthrough (for Inspiron...) Arne Koewing
2003-06-13 21:15 ` [PATCH] Synaptics TouchPad driver for 2.5.70 Peter Osterlund
2003-06-13 21:49 ` James Simmons
2003-06-13 22:08 ` Vojtech Pavlik
2003-06-13 22:55 ` Peter Berg Larsen
2003-06-14 8:42 ` Vojtech Pavlik
2003-06-14 22:19 ` Vojtech Pavlik
2003-06-15 12:18 ` Peter Osterlund
2003-06-15 12:28 ` Vojtech Pavlik
2003-06-15 15:47 ` Peter Osterlund [this message]
2003-06-15 17:27 ` Vojtech Pavlik
2003-06-18 23:41 ` Peter Osterlund
2003-06-19 6:03 ` Vojtech Pavlik
2003-06-23 16:30 ` Andreas Jellinghaus
2003-06-23 19:04 ` Peter Osterlund
2003-06-26 20:01 ` Vojtech Pavlik
2003-07-07 23:06 ` Peter Osterlund
2003-07-12 10:51 ` Andreas Jellinghaus
2003-06-10 22:52 Joseph Fannin
2003-06-11 15:30 ` Joseph Fannin
2003-06-11 20:17 ` Andrew Morton
2003-06-11 20:29 ` Vojtech Pavlik
2003-06-11 22:12 ` Peter Osterlund
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