HID: wacom: Do not completely map WACOM_HID_WD_TOUCHRINGSTATUS usage

BugLink: http://bugs.launchpad.net/bugs/1716284
commit 8d411cbf46e515ca2b7ceb3d2b3f43e22813edac upstream.

The WACOM_HID_WD_TOUCHRINGSTATUS usage is a single bit which tells us
whether the touchring is currently in use or not. Because we need to
reset the axis value to 0 when the finger is removed, we call
'wacom_map_usage' to ensure that the required type/code values are
associated with the usage. The 'wacom_map_usage' also sets up the axis
range and resolution, however, which is not desired in this particular
case.

Although xf86-input-wacom doesn't do really do anything with the ring's
range or resolution, the libinput driver (for Wayland environments)
uses these values to provide proper angle indications to userspace.

Fixes: 60a2218698 ("HID: wacom: generic: add support for touchring")
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 9f940293ede4109b3628e2aa72b1f872d0cc6072..bb17d7bbefd3e7bf033344e7e1bc6b5d5228fd27 100644 (file)
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -1846,7 +1846,13 @@ static void wacom_wac_pad_usage_mapping(struct hid_device *hdev,
                features->device_type |= WACOM_DEVICETYPE_PAD;
                break;
        case WACOM_HID_WD_TOUCHRINGSTATUS:
-               wacom_map_usage(input, usage, field, EV_ABS, ABS_WHEEL, 0);
+               /*
+                * Only set up type/code association. Completely mapping
+                * this usage may overwrite the axis resolution and range.
+                */
+               usage->type = EV_ABS;
+               usage->code = ABS_WHEEL;
+               set_bit(EV_ABS, input->evbit);
                features->device_type |= WACOM_DEVICETYPE_PAD;
                break;
        case WACOM_HID_WD_BUTTONCONFIG: