From: Mikhail Khvainitski me@khvoinitsky.org
[ Upstream commit 46a0a2c96f0f47628190f122c2e3d879e590bcbe ]
Built-in firmware of cptkbd handles scrolling by itself (when middle button is pressed) but with issues: it does not support horizontal and hi-res scrolling and upon middle button release it sends middle button click even if there was a scrolling event. Commit 3cb5ff0220e3 ("HID: lenovo: Hide middle-button press until release") workarounds last issue but it's impossible to workaround scrolling-related issues without firmware modification.
Likely, Dennis Schneider has reverse engineered the firmware and provided an instruction on how to patch it [1]. However, aforementioned workaround prevents userspace (libinput) from knowing exact moment when middle button has been pressed down and performing "On-Button scrolling". This commit detects correctly-behaving patched firmware if cursor movement events has been received during middle button being pressed and stops applying workaround for this device.
Link: https://hohlerde.org/rauch/en/elektronik/projekte/tpkbd-fix/ [1]
Signed-off-by: Mikhail Khvainitski me@khvoinitsky.org Signed-off-by: Jiri Kosina jkosina@suse.cz Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hid/hid-lenovo.c | 68 ++++++++++++++++++++++++++-------------- 1 file changed, 45 insertions(+), 23 deletions(-)
diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c index 0ff03fed97709..71f7b0d539df5 100644 --- a/drivers/hid/hid-lenovo.c +++ b/drivers/hid/hid-lenovo.c @@ -50,7 +50,12 @@ struct lenovo_drvdata { int select_right; int sensitivity; int press_speed; - u8 middlebutton_state; /* 0:Up, 1:Down (undecided), 2:Scrolling */ + /* 0: Up + * 1: Down (undecided) + * 2: Scrolling + * 3: Patched firmware, disable workaround + */ + u8 middlebutton_state; bool fn_lock; };
@@ -478,31 +483,48 @@ static int lenovo_event_cptkbd(struct hid_device *hdev, { struct lenovo_drvdata *cptkbd_data = hid_get_drvdata(hdev);
- /* "wheel" scroll events */ - if (usage->type == EV_REL && (usage->code == REL_WHEEL || - usage->code == REL_HWHEEL)) { - /* Scroll events disable middle-click event */ - cptkbd_data->middlebutton_state = 2; - return 0; - } + if (cptkbd_data->middlebutton_state != 3) { + /* REL_X and REL_Y events during middle button pressed + * are only possible on patched, bug-free firmware + * so set middlebutton_state to 3 + * to never apply workaround anymore + */ + if (cptkbd_data->middlebutton_state == 1 && + usage->type == EV_REL && + (usage->code == REL_X || usage->code == REL_Y)) { + cptkbd_data->middlebutton_state = 3; + /* send middle button press which was hold before */ + input_event(field->hidinput->input, + EV_KEY, BTN_MIDDLE, 1); + input_sync(field->hidinput->input); + }
- /* Middle click events */ - if (usage->type == EV_KEY && usage->code == BTN_MIDDLE) { - if (value == 1) { - cptkbd_data->middlebutton_state = 1; - } else if (value == 0) { - if (cptkbd_data->middlebutton_state == 1) { - /* No scrolling inbetween, send middle-click */ - input_event(field->hidinput->input, - EV_KEY, BTN_MIDDLE, 1); - input_sync(field->hidinput->input); - input_event(field->hidinput->input, - EV_KEY, BTN_MIDDLE, 0); - input_sync(field->hidinput->input); + /* "wheel" scroll events */ + if (usage->type == EV_REL && (usage->code == REL_WHEEL || + usage->code == REL_HWHEEL)) { + /* Scroll events disable middle-click event */ + cptkbd_data->middlebutton_state = 2; + return 0; + } + + /* Middle click events */ + if (usage->type == EV_KEY && usage->code == BTN_MIDDLE) { + if (value == 1) { + cptkbd_data->middlebutton_state = 1; + } else if (value == 0) { + if (cptkbd_data->middlebutton_state == 1) { + /* No scrolling inbetween, send middle-click */ + input_event(field->hidinput->input, + EV_KEY, BTN_MIDDLE, 1); + input_sync(field->hidinput->input); + input_event(field->hidinput->input, + EV_KEY, BTN_MIDDLE, 0); + input_sync(field->hidinput->input); + } + cptkbd_data->middlebutton_state = 0; } - cptkbd_data->middlebutton_state = 0; + return 1; } - return 1; }
return 0;