[PATCH 01/01] Input multitouch: fix horizontal two-finger-scrollingon Sentelic touchpads

From: Christophe TORDEUX
Date: Tue Dec 11 2012 - 20:21:32 EST


From: Christophe TORDEUX <christophe@xxxxxxxxxxx>

Fix horizontal two-finger scrolling on Sentelic touchpads. Currently
horizontal two-fingers scrolling does not work with these touchpads.
The patch also makes vertical two-finger scrolling smoother in some
applications e.g. Firefox.

Signed-off-by: Christophe TORDEUX <christophe@xxxxxxxxxxx>
----

This patch was inspired by the reading of
drivers/input/mouse/synaptics.c. It is known to work (tested) on
Sentelic touchpads version STL3888_C0. Very probably works on all later
versions, and possibly works on some earlier versions of the hardware in
question.

diff -uprN -X vanilla/linux-3.7-rc8/Documentation/dontdiff
vanilla/linux-3.7-rc8/drivers/input/mouse/sentelic.c
linux-3.7-rc8/drivers/input/mouse/sentelic.c
--- vanilla/linux-3.7-rc8/drivers/input/mouse/sentelic.c 2012-12-11 04:32:44.476930522 +0100
+++ linux-3.7-rc8/drivers/input/mouse/sentelic.c 2012-12-12 01:16:41.766018017 +0100
@@ -706,8 +706,10 @@ static psmouse_ret_t fsp_process_byte(st
struct input_dev *dev = psmouse->dev;
struct fsp_data *ad = psmouse->private;
unsigned char *packet = psmouse->packet;
+ unsigned char *last_packet = ad->last_pkt;
unsigned char button_status = 0, lscroll = 0, rscroll = 0;
unsigned short abs_x, abs_y, fgrs = 0;
+ unsigned short last_abs_x, last_abs_y;
int rel_x, rel_y;

if (psmouse->pktcnt < 4)
@@ -734,6 +736,9 @@ static psmouse_ret_t fsp_process_byte(st

abs_x = GET_ABS_X(packet);
abs_y = GET_ABS_Y(packet);
+ last_abs_x = GET_ABS_X(last_packet);
+ last_abs_y = GET_ABS_Y(last_packet);
+ memcpy(ad->last_pkt, packet, psmouse->pktcnt);

if (packet[0] & FSP_PB0_MFMC) {
/*
@@ -753,10 +758,19 @@ static psmouse_ret_t fsp_process_byte(st
*/
fgrs = 1;
fsp_set_slot(dev, 0, false, 0, 0);
+
+ /* We don't need to re-order
+ * coordinates if last finger
+ * was same finger
+ */
+ last_abs_x = abs_x;
+ last_abs_y = abs_y;
}
ad->last_mt_fgr = 2;

- fsp_set_slot(dev, 1, fgrs == 2, abs_x, abs_y);
+ fsp_set_slot(dev, 1, fgrs == 2,
+ max(abs_x, last_abs_x),
+ max(abs_y, last_abs_y));
} else {
/* 1st finger */
if (ad->last_mt_fgr == 1) {
@@ -767,9 +781,18 @@ static psmouse_ret_t fsp_process_byte(st
*/
fgrs = 1;
fsp_set_slot(dev, 1, false, 0, 0);
+
+ /* We don't need to re-order
+ * coordinates if last finger
+ * was same finger
+ */
+ last_abs_x = abs_x;
+ last_abs_y = abs_y;
}
ad->last_mt_fgr = 1;
- fsp_set_slot(dev, 0, fgrs != 0, abs_x, abs_y);
+ fsp_set_slot(dev, 0, fgrs != 0,
+ min(abs_x, last_abs_x),
+ min(abs_y, last_abs_y));
}
} else {
/* SFAC packet */
@@ -788,12 +811,18 @@ static psmouse_ret_t fsp_process_byte(st
if (abs_x != 0 && abs_y != 0)
fgrs = 1;

+ /* We don't need to re-order
+ * coordinates of SFAC packets
+ */
+ last_abs_x = abs_x;
+ last_abs_y = abs_y;
+
fsp_set_slot(dev, 0, fgrs > 0, abs_x, abs_y);
fsp_set_slot(dev, 1, false, 0, 0);
}
if (fgrs > 0) {
- input_report_abs(dev, ABS_X, abs_x);
- input_report_abs(dev, ABS_Y, abs_y);
+ input_report_abs(dev, ABS_X, min(abs_x, last_abs_x));
+ input_report_abs(dev, ABS_Y, min(abs_y, last_abs_y));
}
input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
diff -uprN -X vanilla/linux-3.7-rc8/Documentation/dontdiff vanilla/linux-3.7-rc8/drivers/input/mouse/sentelic.h linux-3.7-rc8/drivers/input/mouse/sentelic.h
--- vanilla/linux-3.7-rc8/drivers/input/mouse/sentelic.h 2012-12-11 04:32:44.476930522 +0100
+++ linux-3.7-rc8/drivers/input/mouse/sentelic.h 2012-12-12 01:16:41.954018011 +0100
@@ -117,6 +117,7 @@ struct fsp_data {
unsigned char last_reg; /* Last register we requested read from */
unsigned char last_val;
unsigned int last_mt_fgr; /* Last seen finger(multitouch) */
+ unsigned char last_pkt[8]; /* Last packet we processed from fsp */
};

#ifdef CONFIG_MOUSE_PS2_SENTELIC

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