From: Dixit Parmar <dixitparmar19@xxxxxxxxx>
For Sitronix st1633 multi-touch controller driver the co-ordinates reported
for multiple fingers were wrong.
So the below mentioned bug was filed,
Bugzilla Bug ID: 204561
While reading co-ordinates from specified I2C registers, the X & Y
co-ordinates should be read from proper I2C address for particular finger as
specified in chip specific datasheet.
for single touch this logic is working fine. However, for multi-touch
scenario the logic of reading data from data buffer has issues.
This patch fixes the reading logic from data buffer.
Previous logic:
* Offset of X & Y Lower byte coordinate is increased by i no. only(by 1 Byte)
for each finger.
New logic:
* The logic of reading X & Y Lower Byte coordinate needs to be increased
by i+y for each time/finger.
Signed-off-by: Dixit Parmar <dixitparmar19@xxxxxxxxx>
---
drivers/input/touchscreen/st1232.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index 3492339..1139714 100644
--- 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)
--
2.7.4
