Input: st1232 - fix reporting multitouch coordinates

BugLink: https://bugs.launchpad.net/bugs/1850456
commit b1a402e75a5f5127ff1ffff0615249f98df8b7b3 upstream.

For Sitronix st1633 multi-touch controller driver the coordinates reported
for multiple fingers were wrong, as it was always taking LSB of coordinates
from the first contact data.

Signed-off-by: Dixit Parmar <dixitparmar19@gmail.com>
Reviewed-by: Martin Kepplinger <martink@posteo.de>
Cc: stable@vger.kernel.org
Fixes: 351e0592bfea ("Input: st1232 - add support for st1633")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204561
Link: https://lore.kernel.org/r/1566209314-21767-1-git-send-email-dixitparmar19@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index 34923399ece4e98534022f90d8ad4180ef4536b6..1139714e72e2672f26a52be85280e7f8fea22e11 100644 (file)
--- a/drivers/input/touchscreen/st1232.c
+++ b/drivers/input/touchscreen/st1232.c
@@ -81,8 +81,10 @@ static int st1232_ts_read_data(struct st1232_ts_data *ts)
        for (i = 0, y = 0; i < ts->chip_info->max_fingers; i++, y += 3) {
                finger[i].is_valid = buf[i + y] >> 7;
                if (finger[i].is_valid) {
-                       finger[i].x = ((buf[i + y] & 0x0070) << 4) | buf[i + 1];
-                       finger[i].y = ((buf[i + y] & 0x0007) << 8) | buf[i + 2];
+                       finger[i].x = ((buf[i + y] & 0x0070) << 4) |
+                                       buf[i + y + 1];
+                       finger[i].y = ((buf[i + y] & 0x0007) << 8) |
+                                       buf[i + y + 2];
 
                        /* st1232 includes a z-axis / touch strength */
                        if (ts->chip_info->have_z)