Input: st1232 - add touch-overlay handling

Use touch-overlay to support overlay objects such as buttons and a
resized frame defined in the device tree.

A key event will be generated if the coordinates of a touch event are
within the area defined by the button properties.

Reviewed-by: Jeff LaBundy <jeff@labundy.com>
Signed-off-by: Javier Carrasco <javier.carrasco@wolfvision.net>
Link: https://lore.kernel.org/r/20241016-feature-ts_virtobj_patch-v11-4-b292a1bbb0a1@wolfvision.net
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: JC-WV

drivers/input/touchscreen/st1232.c

@@ -22,6 +22,7 @@
 #include <linux/pm_qos.h>
 #include <linux/slab.h>
 #include <linux/types.h>
+#include <linux/input/touch-overlay.h>
 
 #define ST1232_TS_NAME	"st1232-ts"
 #define ST1633_TS_NAME	"st1633-ts"
@@ -57,6 +58,7 @@ struct st1232_ts_data {
 	struct dev_pm_qos_request low_latency_req;
 	struct gpio_desc *reset_gpio;
 	const struct st_chip_info *chip_info;
+	struct list_head touch_overlay_list;
 	int read_buf_len;
 	u8 *read_buf;
 };
@@ -156,6 +158,10 @@ static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
 
 	input_mt_assign_slots(input, slots, pos, n_contacts, 0);
 	for (i = 0; i < n_contacts; i++) {
+		if (touch_overlay_process_contact(&ts->touch_overlay_list,
+						  input, &pos[i], slots[i]))
+			continue;
+
 		input_mt_slot(input, slots[i]);
 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
 		input_report_abs(input, ABS_MT_POSITION_X, pos[i].x);
@@ -164,6 +170,7 @@ static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
 			input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]);
 	}
 
+	touch_overlay_sync_frame(&ts->touch_overlay_list, input);
 	input_mt_sync_frame(input);
 	input_sync(input);
 
@@ -292,18 +299,30 @@ static int st1232_ts_probe(struct i2c_client *client)
 	if (error)
 		return error;
 
-	/* Read resolution from the chip */
-	error = st1232_ts_read_resolution(ts, &max_x, &max_y);
-	if (error) {
-		dev_err(&client->dev,
-			"Failed to read resolution: %d\n", error);
-		return error;
-	}
-
 	if (ts->chip_info->have_z)
 		input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
 				     ts->chip_info->max_area, 0, 0);
 
+	/* map overlay objects if defined in the device tree */
+	INIT_LIST_HEAD(&ts->touch_overlay_list);
+	error = touch_overlay_map(&ts->touch_overlay_list, input_dev);
+	if (error)
+		return error;
+
+	if (touch_overlay_mapped_touchscreen(&ts->touch_overlay_list)) {
+		/* Read resolution from the overlay touchscreen if defined */
+		touch_overlay_get_touchscreen_abs(&ts->touch_overlay_list,
+						  &max_x, &max_y);
+	} else {
+		/* Read resolution from the chip */
+		error = st1232_ts_read_resolution(ts, &max_x, &max_y);
+		if (error) {
+			dev_err(&client->dev,
+				"Failed to read resolution: %d\n", error);
+			return error;
+		}
+	}
+
 	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 			     0, max_x, 0, 0);
 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,