HID: wacom: Correct distance scale for 2nd-gen Intuos devices

commit b72fb1dcd2ea9d29417711cb302cef3006fa8d5a upstream.

Distance values reported by 2nd-gen Intuos tablets are on an inverted
scale (0 == far, 63 == near). We need to change them over to a normal
scale before reporting to userspace or else userspace drivers and
applications can get confused.

Ref: https://github.com/linuxwacom/input-wacom/issues/98
Fixes: eda01dab53 ("HID: wacom: Add four new Intuos devices")
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 949761d..fbf14a1 100644 (file)
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -949,6 +949,8 @@ static int wacom_intuos_general(struct wacom_wac *wacom)
                y >>= 1;
                distance >>= 1;
        }
+       if (features->type == INTUOSHT2)
+               distance = features->distance_max - distance;
        input_report_abs(input, ABS_X, x);
        input_report_abs(input, ABS_Y, y);
        input_report_abs(input, ABS_DISTANCE, distance);