@@ -22338,6 +22338,13 @@ L: platform-driver-x86@vger.kernel.org
S: Maintained
F: drivers/platform/x86/toshiba-wmi.c
+TOUCH OVERLAY
+M: Javier Carrasco <javier.carrasco@wolfvision.net>
+L: linux-input@vger.kernel.org
+S: Maintained
+F: drivers/input/touch-overlay.c
+F: include/linux/input/touch-overlay.h
+
TPM DEVICE DRIVER
M: Peter Huewe <peterhuewe@gmx.de>
M: Jarkko Sakkinen <jarkko@kernel.org>
@@ -7,7 +7,7 @@
obj-$(CONFIG_INPUT) += input-core.o
input-core-y := input.o input-compat.o input-mt.o input-poller.o ff-core.o
-input-core-y += touchscreen.o
+input-core-y += touchscreen.o touch-overlay.o
obj-$(CONFIG_INPUT_FF_MEMLESS) += ff-memless.o
obj-$(CONFIG_INPUT_SPARSEKMAP) += sparse-keymap.o
new file mode 100644
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Helper functions for overlay objects on touchscreens
+ *
+ * Copyright (c) 2023 Javier Carrasco <javier.carrasco@wolfvision.net>
+ */
+
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touch-overlay.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/property.h>
+
+struct touch_overlay_segment {
+ struct list_head list;
+ u32 x_origin;
+ u32 y_origin;
+ u32 x_size;
+ u32 y_size;
+ u32 key;
+ bool pressed;
+ int slot;
+};
+
+static int touch_overlay_get_segment(struct fwnode_handle *segment_node,
+ struct touch_overlay_segment *segment,
+ struct input_dev *input)
+{
+ int error;
+
+ error = fwnode_property_read_u32(segment_node, "x-origin",
+ &segment->x_origin);
+ if (error)
+ return error;
+
+ error = fwnode_property_read_u32(segment_node, "y-origin",
+ &segment->y_origin);
+ if (error)
+ return error;
+
+ error = fwnode_property_read_u32(segment_node, "x-size",
+ &segment->x_size);
+ if (error)
+ return error;
+
+ error = fwnode_property_read_u32(segment_node, "y-size",
+ &segment->y_size);
+ if (error)
+ return error;
+
+ error = fwnode_property_read_u32(segment_node, "linux,code",
+ &segment->key);
+ if (!error)
+ input_set_capability(input, EV_KEY, segment->key);
+ else if (error != -EINVAL)
+ return error;
+
+ return 0;
+}
+
+/**
+ * touch_overlay_map - map overlay objects from the device tree and set
+ * key capabilities if buttons are defined.
+ * @list: pointer to the list that will hold the segments
+ * @input: pointer to the already allocated input_dev
+ *
+ * Returns 0 on success and error number otherwise.
+ *
+ * If buttons are defined, key capabilities are set accordingly.
+ */
+int touch_overlay_map(struct list_head *list, struct input_dev *input)
+{
+ struct fwnode_handle *overlay, *fw_segment;
+ struct device *dev = input->dev.parent;
+ struct touch_overlay_segment *segment;
+ int error;
+
+ overlay = device_get_named_child_node(dev, "touch-overlay");
+ if (!overlay)
+ return 0;
+
+ fwnode_for_each_child_node(overlay, fw_segment) {
+ segment = devm_kzalloc(dev, sizeof(*segment), GFP_KERNEL);
+ if (!segment) {
+ error = -ENOMEM;
+ fwnode_handle_put(overlay);
+ break;
+ }
+ error = touch_overlay_get_segment(fw_segment, segment, input);
+ if (error) {
+ fwnode_handle_put(overlay);
+ break;
+ }
+ list_add_tail(&segment->list, list);
+ }
+
+ return error;
+}
+EXPORT_SYMBOL(touch_overlay_map);
+
+/**
+ * touch_overlay_get_touchscreen_abs - get abs size from the touchscreen area.
+ * @list: pointer to the list that holds the segments
+ * @x: horizontal abs
+ * @y: vertical abs
+ */
+void touch_overlay_get_touchscreen_abs(struct list_head *list, u16 *x, u16 *y)
+{
+ struct touch_overlay_segment *segment;
+ struct list_head *ptr;
+
+ list_for_each(ptr, list) {
+ segment = list_entry(ptr, struct touch_overlay_segment, list);
+ if (!segment->key) {
+ *x = segment->x_size - 1;
+ *y = segment->y_size - 1;
+ break;
+ }
+ }
+}
+EXPORT_SYMBOL(touch_overlay_get_touchscreen_abs);
+
+static bool touch_overlay_segment_event(struct touch_overlay_segment *seg,
+ u32 x, u32 y)
+{
+ if (!seg)
+ return false;
+
+ if (x >= seg->x_origin && x < (seg->x_origin + seg->x_size) &&
+ y >= seg->y_origin && y < (seg->y_origin + seg->y_size))
+ return true;
+
+ return false;
+}
+
+/**
+ * touch_overlay_mapped_touchscreen - check if a touchscreen area is mapped
+ * @list: pointer to the list that holds the segments
+ *
+ * Returns true if a touchscreen area is mapped or false otherwise.
+ */
+bool touch_overlay_mapped_touchscreen(struct list_head *list)
+{
+ struct touch_overlay_segment *segment;
+ struct list_head *ptr;
+
+ list_for_each(ptr, list) {
+ segment = list_entry(ptr, struct touch_overlay_segment, list);
+ if (!segment->key)
+ return true;
+ }
+
+ return false;
+}
+EXPORT_SYMBOL(touch_overlay_mapped_touchscreen);
+
+static bool touch_overlay_event_on_ts(struct list_head *list, u32 *x, u32 *y)
+{
+ struct touch_overlay_segment *segment;
+ struct list_head *ptr;
+ bool valid_touch = true;
+
+ if (!x || !y)
+ return false;
+
+ list_for_each(ptr, list) {
+ segment = list_entry(ptr, struct touch_overlay_segment, list);
+ if (segment->key)
+ continue;
+
+ if (touch_overlay_segment_event(segment, *x, *y)) {
+ *x -= segment->x_origin;
+ *y -= segment->y_origin;
+ return true;
+ }
+ /* ignore touch events outside the defined area */
+ valid_touch = false;
+ }
+
+ return valid_touch;
+}
+
+static bool touch_overlay_button_event(struct input_dev *input,
+ struct touch_overlay_segment *segment,
+ const u32 *x, const u32 *y, u32 slot)
+{
+ bool contact = x && y;
+
+ if (!contact && segment->pressed && segment->slot == slot) {
+ segment->pressed = false;
+ input_report_key(input, segment->key, false);
+ input_sync(input);
+ return true;
+ } else if (contact && touch_overlay_segment_event(segment, *x, *y)) {
+ segment->pressed = true;
+ segment->slot = slot;
+ input_report_key(input, segment->key, true);
+ input_sync(input);
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * touch_overlay_process_event - process input events according to the overlay
+ * mapping. This function acts as a filter to release the calling driver from
+ * the events that are either related to overlay buttons or out of the overlay
+ * touchscreen area, if defined.
+ * @list: pointer to the list that holds the segments
+ * @input: pointer to the input device associated to the event
+ * @x: pointer to the x coordinate (NULL if not available - no contact)
+ * @y: pointer to the y coordinate (NULL if not available - no contact)
+ * @slot: slot associated to the event
+ *
+ * Returns true if the event was processed (reported for valid key events
+ * and dropped for events outside the overlay touchscreen area) or false
+ * if the event must be processed by the caller. In that case this function
+ * shifts the (x,y) coordinates to the overlay touchscreen axis if required.
+ */
+bool touch_overlay_process_event(struct list_head *list,
+ struct input_dev *input,
+ u32 *x, u32 *y, u32 slot)
+{
+ struct touch_overlay_segment *segment;
+ struct list_head *ptr;
+
+ /*
+ * buttons must be prioritized over overlay touchscreens to account for
+ * overlappings e.g. a button inside the touchscreen area.
+ */
+ list_for_each(ptr, list) {
+ segment = list_entry(ptr, struct touch_overlay_segment, list);
+ if (segment->key &&
+ touch_overlay_button_event(input, segment, x, y, slot)) {
+ return true;
+ }
+ }
+
+ /*
+ * valid touch events on the overlay touchscreen are left for the client
+ * to be processed/reported according to its (possibly) unique features.
+ */
+ return !touch_overlay_event_on_ts(list, x, y);
+}
+EXPORT_SYMBOL(touch_overlay_process_event);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Helper functions for overlay objects on touch devices");
new file mode 100644
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2023 Javier Carrasco <javier.carrasco@wolfvision.net>
+ */
+
+#ifndef _TOUCH_OVERLAY
+#define _TOUCH_OVERLAY
+
+#include <linux/types.h>
+
+struct input_dev;
+
+int touch_overlay_map(struct list_head *list, struct input_dev *input);
+
+void touch_overlay_get_touchscreen_abs(struct list_head *list, u16 *x, u16 *y);
+
+bool touch_overlay_mapped_touchscreen(struct list_head *list);
+
+bool touch_overlay_process_event(struct list_head *list, struct input_dev *input,
+ u32 *x, u32 *y, u32 slot);
+
+#endif