diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c index 773fa114b216a..033cc032f45cb 100644 --- a/drivers/hid/wacom_sys.c +++ b/drivers/hid/wacom_sys.c @@ -240,6 +240,30 @@ static void wacom_usage_mapping(struct hid_device *hdev, features->touch_max = 1; } + /* + * ISDv4 devices which predate HID's adoption of the + * HID_DG_BARELSWITCH2 usage use 0x000D0000 in its + * position instead. We can accurately detect if a + * usage with that value should be HID_DG_BARRELSWITCH2 + * based on the surrounding usages, which have remained + * constant across generations. + */ + if (features->type == HID_GENERIC && + usage->hid == 0x000D0000 && + field->application == HID_DG_PEN && + field->physical == HID_DG_STYLUS) { + int i = usage->usage_index; + + if (i-4 >= 0 && i+1 < field->maxusage && + field->usage[i-4].hid == HID_DG_TIPSWITCH && + field->usage[i-3].hid == HID_DG_BARRELSWITCH && + field->usage[i-2].hid == HID_DG_ERASER && + field->usage[i-1].hid == HID_DG_INVERT && + field->usage[i+1].hid == HID_DG_INRANGE) { + usage->hid = HID_DG_BARRELSWITCH2; + } + } + switch (usage->hid) { case HID_GD_X: features->x_max = field->logical_maximum;