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 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 overlays handling .../input/touchscreen/sitronix,st1232.yaml | 29 +++ .../bindings/input/touchscreen/touchscreen.yaml | 119 ++++++++++ MAINTAINERS | 7 + drivers/input/Makefile | 2 +- drivers/input/touch-overlay.c | 264 +++++++++++++++++++++ drivers/input/touchscreen/st1232.c | 48 ++-- include/linux/input/touch-overlay.h | 22 ++ 7 files changed, 476 insertions(+), 15 deletions(-) --- base-commit: f2661062f16b2de5d7b6a5c42a9a5c96326b8454 change-id: 20230510-feature-ts_virtobj_patch-e267540aae74 Best regards, -- Javier Carrasco <javier.carrasco@xxxxxxxxxxxxxx>
