Input: mma8450 - fix signed 12bits to 32bits conversion

Event value is wrong. Should be in range -2048 to 2047, but is in
range 0 to 4095.  Use s8 to int conversion and remove 0xfff mask.

Signed-off-by: Sebastien Royen <sebastien.royen@armadeus.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c
index 480557f14f23ec74f05df47f7c6c9bee8ab2ec8c..f3309696d053ae0692a21e39766806fd62ab9957 100644 (file)
--- a/drivers/input/misc/mma8450.c
+++ b/drivers/input/misc/mma8450.c
@@ -123,9 +123,9 @@ static void mma8450_poll(struct input_polled_dev *dev)
        if (ret < 0)
                return;
 
-       x = ((buf[1] << 4) & 0xff0) | (buf[0] & 0xf);
-       y = ((buf[3] << 4) & 0xff0) | (buf[2] & 0xf);
-       z = ((buf[5] << 4) & 0xff0) | (buf[4] & 0xf);
+       x = ((int)(s8)buf[1] << 4) | (buf[0] & 0xf);
+       y = ((int)(s8)buf[3] << 4) | (buf[2] & 0xf);
+       z = ((int)(s8)buf[5] << 4) | (buf[4] & 0xf);
 
        input_report_abs(dev->input, ABS_X, x);
        input_report_abs(dev->input, ABS_Y, y);