selftests/hid: add Huion Kamvas Pro 19 tests

This tablets gets a lot of things wrong:
- the secondary button is reported through Secondary Tip Switch
- the third button is reported through Invert

We need to add some out of proximity intermediate state when moving
back and forth with the eraser mode as it can only be triggered by
physically returning the pen, meaning that the tolerated transitions
can never happen.

Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Peter Hutterer <[e-mail]>
Signed-off-by: Benjamin Tissoires <[e-mail]>

tools/testing/selftests/hid/tests/test_tablet.py

···
 
     PRIMARY_PRESSED = libevdev.EV_KEY.BTN_STYLUS
     SECONDARY_PRESSED = libevdev.EV_KEY.BTN_STYLUS2
+    THIRD_PRESSED = libevdev.EV_KEY.BTN_STYLUS3
 
 
 class PenState(Enum):
···
         buttons = [
             BtnPressed.PRIMARY_PRESSED,
             BtnPressed.SECONDARY_PRESSED,
+            BtnPressed.THIRD_PRESSED,
         ]
         if button is not None:
             buttons.remove(button)
···
                 scribble,
                 allow_intermediate_states=False,
                 button=BtnPressed.SECONDARY_PRESSED,
+            )
+
+        @pytest.mark.skip_if_uhdev(
+            lambda uhdev: "Third Barrel Switch" not in uhdev.fields,
+            "Device not compatible, missing Third Barrel Switch usage",
+        )
+        @pytest.mark.parametrize("scribble", [True, False], ids=["scribble", "static"])
+        @pytest.mark.parametrize(
+            "state_list",
+            [
+                pytest.param(v, id=k)
+                for k, v in PenState.legal_transitions_with_button().items()
+            ],
+        )
+        def test_valid_third_button_pen_states(self, state_list, scribble):
+            """Rework the transition state machine by adding the secondary button."""
+            self._test_states(
+                state_list,
+                scribble,
+                allow_intermediate_states=False,
+                button=BtnPressed.THIRD_PRESSED,
             )
 
         @pytest.mark.skip_if_uhdev(
···
         return rs
 
 
+class Huion_Kamvas_Pro_19_256c_006b(PenDigitizer):
+    """
+    Pen that reports secondary barrel switch through secondary TipSwtich
+    and 3rd button through Invert
+    """
+
+    def __init__(
+        self,
+        name,
+        rdesc_str=None,
+        rdesc=None,
+        application="Stylus",
+        physical=None,
+        input_info=(BusType.USB, 0x256C, 0x006B),
+        evdev_name_suffix=None,
+    ):
+        super().__init__(
+            name, rdesc_str, rdesc, application, physical, input_info, evdev_name_suffix
+        )
+        self.fields.append("Secondary Barrel Switch")
+        self.fields.append("Third Barrel Switch")
+        self.previous_state = PenState.PEN_IS_OUT_OF_RANGE
+
+    def move_to(self, pen, state, button, debug=True):
+        # fill in the previous values
+        if pen.current_state == PenState.PEN_IS_OUT_OF_RANGE:
+            pen.restore()
+
+        if debug:
+            print(f"\n  *** pen is moving to {state} ***")
+
+        if state == PenState.PEN_IS_OUT_OF_RANGE:
+            pen.backup()
+            pen.tipswitch = False
+            pen.tippressure = 0
+            pen.azimuth = 0
+            pen.inrange = False
+            pen.width = 0
+            pen.height = 0
+            pen.invert = False
+            pen.eraser = False
+            pen.xtilt = 0
+            pen.ytilt = 0
+            pen.twist = 0
+            pen.barrelswitch = False
+            pen.secondarytipswitch = False
+        elif state == PenState.PEN_IS_IN_RANGE:
+            pen.tipswitch = False
+            pen.inrange = True
+            pen.invert = False
+            pen.eraser = False
+            pen.barrelswitch = False
+            pen.secondarytipswitch = False
+        elif state == PenState.PEN_IS_IN_CONTACT:
+            pen.tipswitch = True
+            pen.inrange = True
+            pen.invert = False
+            pen.eraser = False
+            pen.barrelswitch = False
+            pen.secondarytipswitch = False
+        elif state == PenState.PEN_IS_IN_RANGE_WITH_BUTTON:
+            pen.tipswitch = False
+            pen.inrange = True
+            pen.eraser = False
+            assert button is not None
+            pen.barrelswitch = button == BtnPressed.PRIMARY_PRESSED
+            pen.secondarytipswitch = button == BtnPressed.SECONDARY_PRESSED
+            pen.invert = button == BtnPressed.THIRD_PRESSED
+        elif state == PenState.PEN_IS_IN_CONTACT_WITH_BUTTON:
+            pen.tipswitch = True
+            pen.inrange = True
+            pen.eraser = False
+            assert button is not None
+            pen.barrelswitch = button == BtnPressed.PRIMARY_PRESSED
+            pen.secondarytipswitch = button == BtnPressed.SECONDARY_PRESSED
+            pen.invert = button == BtnPressed.THIRD_PRESSED
+        elif state == PenState.PEN_IS_IN_RANGE_WITH_ERASING_INTENT:
+            pen.tipswitch = False
+            pen.inrange = True
+            pen.invert = True
+            pen.eraser = False
+            pen.barrelswitch = False
+            pen.secondarytipswitch = False
+        elif state == PenState.PEN_IS_ERASING:
+            pen.tipswitch = False
+            pen.inrange = True
+            pen.invert = False
+            pen.eraser = True
+            pen.barrelswitch = False
+            pen.secondarytipswitch = False
+
+        pen.current_state = state
+
+    def call_input_event(self, report):
+        if report[0] == 0x0a:
+            # ensures the original second Eraser usage is null
+            report[1] &= 0xdf
+
+            # ensures the original last bit is equal to bit 6 (In Range)
+            if report[1] & 0x40:
+                report[1] |= 0x80
+
+        super().call_input_event(report)
+
+    def send_intermediate_state(self, pen, state, test_button):
+        intermediate_pen = copy.copy(pen)
+        self.move_to(intermediate_pen, state, test_button, debug=False)
+        return super().event(intermediate_pen, test_button)
+
+    def event(self, pen, button):
+        rs = []
+
+        # it's not possible to go between eraser mode or not without
+        # going out-of-prox: the eraser mode is activated by presenting
+        # the tail of the pen
+        if self.previous_state in (
+            PenState.PEN_IS_IN_RANGE,
+            PenState.PEN_IS_IN_RANGE_WITH_BUTTON,
+            PenState.PEN_IS_IN_CONTACT,
+            PenState.PEN_IS_IN_CONTACT_WITH_BUTTON,
+        ) and pen.current_state in (
+            PenState.PEN_IS_IN_RANGE_WITH_ERASING_INTENT,
+            PenState.PEN_IS_IN_RANGE_WITH_ERASING_INTENT_WITH_BUTTON,
+            PenState.PEN_IS_ERASING,
+            PenState.PEN_IS_ERASING_WITH_BUTTON,
+        ):
+            rs.extend(
+                self.send_intermediate_state(pen, PenState.PEN_IS_OUT_OF_RANGE, button)
+            )
+
+        # same than above except from eraser to normal
+        if self.previous_state in (
+            PenState.PEN_IS_IN_RANGE_WITH_ERASING_INTENT,
+            PenState.PEN_IS_IN_RANGE_WITH_ERASING_INTENT_WITH_BUTTON,
+            PenState.PEN_IS_ERASING,
+            PenState.PEN_IS_ERASING_WITH_BUTTON,
+        ) and pen.current_state in (
+            PenState.PEN_IS_IN_RANGE,
+            PenState.PEN_IS_IN_RANGE_WITH_BUTTON,
+            PenState.PEN_IS_IN_CONTACT,
+            PenState.PEN_IS_IN_CONTACT_WITH_BUTTON,
+        ):
+            rs.extend(
+                self.send_intermediate_state(pen, PenState.PEN_IS_OUT_OF_RANGE, button)
+            )
+
+        if self.previous_state == PenState.PEN_IS_OUT_OF_RANGE:
+            if pen.current_state == PenState.PEN_IS_IN_RANGE_WITH_BUTTON:
+                rs.extend(
+                    self.send_intermediate_state(pen, PenState.PEN_IS_IN_RANGE, button)
+                )
+
+        rs.extend(super().event(pen, button))
+        self.previous_state = pen.current_state
+        return rs
+
+
 ################################################################################
 #
 # Windows 7 compatible devices
···
             "uhid test XPPen Artist 24 28bd 093a",
             rdesc="05 0d 09 02 a1 01 85 07 09 20 a1 00 09 42 09 44 09 45 15 00 25 01 75 01 95 03 81 02 95 02 81 03 09 32 95 01 81 02 95 02 81 03 75 10 95 01 35 00 a4 05 01 09 30 65 13 55 0d 46 f0 50 26 ff 7f 81 02 09 31 46 91 2d 26 ff 7f 81 02 b4 09 30 45 00 26 ff 1f 81 42 09 3d 15 81 25 7f 75 08 95 01 81 02 09 3e 15 81 25 7f 81 02 c0 c0",
             input_info=(BusType.USB, 0x28BD, 0x093A),
+        )
+
+
+class TestHuion_Kamvas_Pro_19_256c_006b(BaseTest.TestTablet):
+    hid_bpfs = [("Huion__Kamvas-Pro-19.bpf.o", True)]
+
+    def create_device(self):
+        return Huion_Kamvas_Pro_19_256c_006b(
+            "uhid test HUION Huion Tablet_GT1902",
+            rdesc="05 0d 09 02 a1 01 85 0a 09 20 a1 01 09 42 09 44 09 43 09 3c 09 45 15 00 25 01 75 01 95 06 81 02 09 32 75 01 95 01 81 02 81 03 05 01 09 30 09 31 55 0d 65 33 26 ff 7f 35 00 46 00 08 75 10 95 02 81 02 05 0d 09 30 26 ff 3f 75 10 95 01 81 02 09 3d 09 3e 15 a6 25 5a 75 08 95 02 81 02 c0 c0 05 0d 09 04 a1 01 85 04 09 22 a1 02 05 0d 95 01 75 06 09 51 15 00 25 3f 81 02 09 42 25 01 75 01 95 01 81 02 75 01 95 01 81 03 05 01 75 10 55 0e 65 11 09 30 26 ff 7f 35 00 46 15 0c 81 42 09 31 26 ff 7f 46 cb 06 81 42 05 0d 09 30 26 ff 1f 75 10 95 01 81 02 c0 05 0d 09 22 a1 02 05 0d 95 01 75 06 09 51 15 00 25 3f 81 02 09 42 25 01 75 01 95 01 81 02 75 01 95 01 81 03 05 01 75 10 55 0e 65 11 09 30 26 ff 7f 35 00 46 15 0c 81 42 09 31 26 ff 7f 46 cb 06 81 42 05 0d 09 30 26 ff 1f 75 10 95 01 81 02 c0 05 0d 09 56 55 00 65 00 27 ff ff ff 7f 95 01 75 20 81 02 09 54 25 7f 95 01 75 08 81 02 75 08 95 08 81 03 85 05 09 55 25 0a 75 08 95 01 b1 02 06 00 ff 09 c5 85 06 15 00 26 ff 00 75 08 96 00 01 b1 02 c0",
+            input_info=(BusType.USB, 0x256C, 0x006B),
         )