Merge tag 'v4.2-rc3' into next

[cascardo/linux.git] / drivers / input / joydev.c

diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c
index 4686260..6cb5a3e 100644 (file)
--- a/drivers/input/joydev.c
+++ b/drivers/input/joydev.c
@@ -747,6 +747,63 @@ static void joydev_cleanup(struct joydev *joydev)
                input_close_device(handle);
 }
 
+static bool joydev_dev_is_absolute_mouse(struct input_dev *dev)
+{
+       DECLARE_BITMAP(jd_scratch, KEY_CNT);
+
+       BUILD_BUG_ON(ABS_CNT > KEY_CNT || EV_CNT > KEY_CNT);
+
+       /*
+        * Virtualization (VMware, etc) and remote management (HP
+        * ILO2) solutions use absolute coordinates for their virtual
+        * pointing devices so that there is one-to-one relationship
+        * between pointer position on the host screen and virtual
+        * guest screen, and so their mice use ABS_X, ABS_Y and 3
+        * primary button events. This clashes with what joydev
+        * considers to be joysticks (a device with at minimum ABS_X
+        * axis).
+        *
+        * Here we are trying to separate absolute mice from
+        * joysticks. A device is, for joystick detection purposes,
+        * considered to be an absolute mouse if the following is
+        * true:
+        *
+        * 1) Event types are exactly EV_ABS, EV_KEY and EV_SYN.
+        * 2) Absolute events are exactly ABS_X and ABS_Y.
+        * 3) Keys are exactly BTN_LEFT, BTN_RIGHT and BTN_MIDDLE.
+        * 4) Device is not on "Amiga" bus.
+        */
+
+       bitmap_zero(jd_scratch, EV_CNT);
+       __set_bit(EV_ABS, jd_scratch);
+       __set_bit(EV_KEY, jd_scratch);
+       __set_bit(EV_SYN, jd_scratch);
+       if (!bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
+               return false;
+
+       bitmap_zero(jd_scratch, ABS_CNT);
+       __set_bit(ABS_X, jd_scratch);
+       __set_bit(ABS_Y, jd_scratch);
+       if (!bitmap_equal(dev->absbit, jd_scratch, ABS_CNT))
+               return false;
+
+       bitmap_zero(jd_scratch, KEY_CNT);
+       __set_bit(BTN_LEFT, jd_scratch);
+       __set_bit(BTN_RIGHT, jd_scratch);
+       __set_bit(BTN_MIDDLE, jd_scratch);
+
+       if (!bitmap_equal(dev->keybit, jd_scratch, KEY_CNT))
+               return false;
+
+       /*
+        * Amiga joystick (amijoy) historically uses left/middle/right
+        * button events.
+        */
+       if (dev->id.bustype == BUS_AMIGA)
+               return false;
+
+       return true;
+}
 
 static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 {
@@ -758,6 +815,10 @@ static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
        if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
                return false;
 
+       /* Avoid absolute mice */
+       if (joydev_dev_is_absolute_mouse(dev))
+               return false;
+
        return true;
 }