Some touchscreens are shipped with a physical layer on top of them where
a number of buttons and a resized touchscreen surface might be available.
In order to generate proper key events by overlay buttons and adjust the
touch events to a clipped surface, this series offers a documented,
device-tree-based solution by means of helper functions.
An implementation for a specific touchscreen driver is also included.
The functions in touch-overlay provide a simple workflow to acquire
physical objects from the device tree, map them into a list and generate
events according to the object descriptions.
This feature has been tested with a JT240MHQS-E3 display, which consists
of an st1624 as the base touchscreen and an overlay with two buttons and
a frame that clips its effective surface mounted on it.
To: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
To: Rob Herring <robh@xxxxxxxxxx>
To: Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>
To: Conor Dooley <conor+dt@xxxxxxxxxx>
To: Bastian Hecht <hechtb@xxxxxxxxx>
To: Michael Riesch <michael.riesch@xxxxxxxxxxxxxx>
Cc: linux-input@xxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Javier Carrasco <javier.carrasco@xxxxxxxxxxxxxx>
Changes in v11:
- {touch-overlay,st1232}.c: work on assigned slots instead of positions
retrieved by the sensor to account for those that don't track the
contacts themselves.
- touch-overlay.c: do not emit sync and rely on the driver calling it.
- touch-overlay.c: use cleanup attribute for fwnode_handle *overlay.
- touch-overlay.c: simplify return paths in touch_overlay_map().
- touch-overlay.c: drop validity check in touch_overlay_segment_event()
(internal function, not API).
- Link to v10: https://lore.kernel.org/r/20240626-feature-ts_virtobj_patch-v10-0-873ad79bb2c9@xxxxxxxxxxxxxx
Changes in v10:
- touch-overlay.c: use fwnode_for_each_available_child_node() macro as
there is no point in adding unavailable objects.
- touch-overlay.c: initialize error in touch_overlay_map(), which would
be returned uninitialized if there were no touch overlay segments.
- touch-overlay.c: fix fwnode_handle refcount (overlay must always be
decremented before returning, fw_segment in error paths of the loop).
- Patch 4/4: update description (the feature does not add a second input
device anymore).
- Link to v9: https://lore.kernel.org/r/20240422-feature-ts_virtobj_patch-v9-0-acf118d12a8a@xxxxxxxxxxxxxx
Changes in v9:
- touch-overlay.c: trigger a button release if the finger slides out of
the button segment to be consistent with the button press when sliding
into a button segment (see touch_overlay_button_event()).
- touch-overlay.c: (nit) remove braces in if with a single statement in
touch_overaly_process_event().
- Link to v8: https://lore.kernel.org/r/20240320-feature-ts_virtobj_patch-v8-0-cab6e7dcb1f6@xxxxxxxxxxxxxx
Changes in v8:
- touchscreen bindings: fix description formatting.
- Link to v7: https://lore.kernel.org/r/20240119-feature-ts_virtobj_patch-v7-0-eda70985808f@xxxxxxxxxxxxxx
Changes in v7:
- General: return to a single input device implementation.
- touchscreen bindings: segment instead of button in the label
description.
- touch-overlay.c: define button-specific data inside segment struct.
- touch-overlay.c: remove fwnode_property_present() and check return
value of fwnode_property_read_u32() in touch_overlay_get_segment().
- touch-overlay.c: simplify return path in touch_overlay_map().
- Link to v6: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v6-0-d8a605975153@xxxxxxxxxxxxxx
Changes in v6:
- General: use a single list to manage a single type of object.
- General: swap patches to have bindings preceding the code.
- touch-overlay.c: minor code-sytle fixes.
- Link to v5: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v5-0-ff6b5c4db693@xxxxxxxxxxxxxx
Changes in v5:
- touchscreen bindings: move overlay common properties to a $def entry (Rob Herring)
- st1232 bindings: move overlays to the existing example instead of
making a new one (Rob Herring)
- Link to v4: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v4-0-5c6c0fc1eed6@xxxxxxxxxxxxxx
Changes in v4:
- General: rename "touchscreen" to "touch" to include other consumers.
- PATCH 1/4: move touch-overlay feature to input core.
- PATCH 1/4, 3/4: set key caps and report key events without consumer's
intervention.
- PATCH 2/4: add missing 'required' field with the required properties.
- Link to v3: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v3-0-b4fb7fc4bab7@xxxxxxxxxxxxxx
Changes in v3:
- General: rename "virtobj" and "virtual" to "overlay"
- PATCH 1/4: Make feature bool instead of tristate (selected by
supported touchscreens)
- Link to v2: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v2-0-f68a6bfe7a0f@xxxxxxxxxxxxxx
Changes in v2:
- PATCH 1/4: remove preprocessor directives (the module is selected by
the drivers that support the feature). Typo in the commit message.
- PATCH 2/4: more detailed documentation. Images and examples were added.
- PATCH 3/4: select ts-virtobj automatically.
- Link to v1: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v1-0-5ae5e81bc264@xxxxxxxxxxxxxx
---
Javier Carrasco (4):
dt-bindings: touchscreen: add touch-overlay property
Input: touch-overlay - Add touchscreen overlay handling
dt-bindings: input: touchscreen: st1232: add touch-overlay example
Input: st1232 - add touch-overlay handling
.../input/touchscreen/sitronix,st1232.yaml | 29 +++
.../bindings/input/touchscreen/touchscreen.yaml | 119 +++++++++
MAINTAINERS | 7 +
drivers/input/Makefile | 2 +-
drivers/input/touch-overlay.c | 277 +++++++++++++++++++++
drivers/input/touchscreen/st1232.c | 35 ++-
include/linux/input/touch-overlay.h | 25 ++
7 files changed, 485 insertions(+), 9 deletions(-)
---
base-commit: 9852d85ec9d492ebef56dc5f229416c925758edc
change-id: 20230510-feature-ts_virtobj_patch-e267540aae74
Best regards,
--
Javier Carrasco <javier.carrasco@xxxxxxxxxxxxxx>
