| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128 |
- .. _t440_support:
- ==============================================================================
- Lenovo \*40 series touchpad support
- ==============================================================================
- The Lenovo \*40 series emulates trackstick buttons on the top part of the
- touchpads.
- .. _t440_support_overview:
- ------------------------------------------------------------------------------
- Overview
- ------------------------------------------------------------------------------
- The Lenovo \*40 series introduced a new type of touchpad. Previously, all
- laptops had a separate set of physical buttons for the
- `trackstick <http://en.wikipedia.org/wiki/Pointing_stick>`_. This
- series removed these buttons, relying on a software emulation of the top
- section of the touchpad. This is visually marked on the trackpad itself,
- and clicks can be triggered by pressing the touchpad down with a finger in
- the respective area:
- .. figure:: top-software-buttons.svg
- :align: center
- Left, right and middle-button click with top software button areas
- This page only covers the top software buttons, the bottom button behavior
- is covered in :ref:`Clickpad software buttons <clickpad_softbuttons>`.
- Clickpads with a top button area are marked with the
- `INPUT_PROP_TOPBUTTONPAD <https://www.kernel.org/doc/Documentation/input/event-codes.txt>`_
- property.
- .. _t440_support_btn_size:
- ------------------------------------------------------------------------------
- Size of the buttons
- ------------------------------------------------------------------------------
- The size of the buttons matches the visual markings on this touchpad.
- The width of the left and right buttons is approximately 42% of the
- touchpad's width, the middle button is centered and assigned 16% of the
- touchpad width.
- The line of the buttons is 5mm from the top edge of the touchpad,
- measurements of button presses showed that the size of the buttons needs to
- be approximately 10mm high to work reliable (especially when using the
- thumb to press the button).
- .. _t440_support_btn_behavior:
- ------------------------------------------------------------------------------
- Button behavior
- ------------------------------------------------------------------------------
- Movement in the top button area does not generate pointer movement. These
- buttons are not replacement buttons for the bottom button area but have
- their own behavior. Semantically attached to the trackstick device, libinput
- re-routes events from these buttons to appear through the trackstick device.
- .. graphviz::
- digraph top_button_routing
- {
- rankdir="LR";
- node [shape="box";]
- trackstick [label="trackstick kernel device"];
- touchpad [label="touchpad kernel device"];
- subgraph cluster0 {
- bgcolor = floralwhite
- label = "libinput"
- libinput_ts [label="trackstick libinput_device"
- style=filled
- fillcolor=white];
- libinput_tp [label="touchpad libinput_device"
- style=filled
- fillcolor=white];
- libinput_tp -> libinput_ts [constraint=false
- color="red4"];
- }
- trackstick -> libinput_ts [arrowhead="none"]
- touchpad -> libinput_tp [color="red4"]
- events_tp [label="other touchpad events"];
- events_topbutton [label="top software button events"];
- libinput_tp -> events_tp [arrowhead="none"]
- libinput_ts -> events_topbutton [color="red4"]
- }
- The top button areas work even if the touchpad is disabled but will be
- disabled when the trackstick device is disabled. If the finger starts inside
- the top area and moves outside the button area the finger is treated as dead
- and must be lifted to generate future buttons. Likewise, movement into the
- top button area does not trigger button events, a click has to start inside
- this area to take effect.
- .. _t440_support_identification:
- ------------------------------------------------------------------------------
- Kernel support
- ------------------------------------------------------------------------------
- The firmware on the first generation of touchpads providing top software
- buttons is buggy and announces wrong ranges.
- `Kernel patches <https://lkml.org/lkml/2014/3/7/722>`_ are required;
- these fixes are available in kernels 3.14.1, 3.15 and later but each
- touchpad needs a separate fix.
- The October 2014 refresh of these laptops do not have this firmware bug
- anymore and should work without per-device patches, though
- `this kernel commit <http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=02e07492cdfae9c86e3bd21c0beec88dbcc1e9e8>`_
- is required.
- For a complete list of supported touchpads check
- `the kernel source <http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/input/mouse/synaptics.c>`_
- (search for "topbuttonpad_pnp_ids").
|
