[PATCH v3 3/4] Input: st1232 - add overlay touchscreen and buttons handling

[Javier Carrasco <javier.carrasco@wolfvision.net>]

Use ts-overlay to support overlay objects such as buttons and resized
frames defined in the device tree.

If a overlay-touchscreen is provided, ignore touch events outside of
the area defined by its properties. Otherwise, transform the event
coordinates to the overlay-touchscreen x and y-axis if required.

If buttons are provided, register an additional device to report key
events separately. A key event will be generated if the coordinates
of a touch event are within the area defined by the button properties.

Signed-off-by: Javier Carrasco <javier.carrasco@wolfvision.net>
---
 drivers/input/touchscreen/Kconfig  |  1 +
 drivers/input/touchscreen/st1232.c | 87 ++++++++++++++++++++++++++++++--------
 2 files changed, 70 insertions(+), 18 deletions(-)

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 8382a4d68326..202e559371e8 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1215,6 +1215,7 @@ config TOUCHSCREEN_SIS_I2C
 config TOUCHSCREEN_ST1232
 	tristate "Sitronix ST1232 or ST1633 touchscreen controllers"
 	depends on I2C
+	select TOUCHSCREEN_TS_OVERLAY
 	help
 	  Say Y here if you want to support the Sitronix ST1232
 	  or ST1633 touchscreen controller.
diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index f49566dc96f8..7d8a69e4831b 100644
--- a/drivers/input/touchscreen/st1232.c
+++ b/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/ts-overlay.h>
 
 #define ST1232_TS_NAME	"st1232-ts"
 #define ST1633_TS_NAME	"st1633-ts"
@@ -56,6 +57,8 @@ struct st1232_ts_data {
 	struct touchscreen_properties prop;
 	struct dev_pm_qos_request low_latency_req;
 	struct gpio_desc *reset_gpio;
+	struct input_dev *overlay_keypad;
+	struct ts_overlay_map *map;
 	const struct st_chip_info *chip_info;
 	int read_buf_len;
 	u8 *read_buf;
@@ -129,10 +132,12 @@ static int st1232_ts_read_resolution(struct st1232_ts_data *ts, u16 *max_x,
 
 static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
 {
-	struct input_dev *input = ts->input_dev;
+	struct input_dev *tscreen = ts->input_dev;
+	__maybe_unused struct input_dev *keypad = ts->overlay_keypad;
 	struct input_mt_pos pos[ST_TS_MAX_FINGERS];
 	u8 z[ST_TS_MAX_FINGERS];
 	int slots[ST_TS_MAX_FINGERS];
+	__maybe_unused bool button_pressed[ST_TS_MAX_FINGERS];
 	int n_contacts = 0;
 	int i;
 
@@ -143,6 +148,15 @@ static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
 			unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
 			unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
 
+			/* forward button presses to the keypad input device */
+			if (ts_overlay_is_button_slot(ts->map, i) ||
+			    ts_overlay_button_press(ts->map, keypad, x, y, i)) {
+				button_pressed[i] = true;
+				continue;
+			}
+			/* Ignore events out of the overlay screen if defined */
+			if (!ts_overlay_mt_on_touchscreen(ts->map, &x, &y))
+				continue;
 			touchscreen_set_mt_pos(&pos[n_contacts],
 					       &ts->prop, x, y);
 
@@ -154,18 +168,25 @@ static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
 		}
 	}
 
-	input_mt_assign_slots(input, slots, pos, n_contacts, 0);
+	input_mt_assign_slots(tscreen, slots, pos, n_contacts, 0);
 	for (i = 0; i < n_contacts; i++) {
-		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);
-		input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y);
+		input_mt_slot(tscreen, slots[i]);
+		input_mt_report_slot_state(tscreen, MT_TOOL_FINGER, true);
+		input_report_abs(tscreen, ABS_MT_POSITION_X, pos[i].x);
+		input_report_abs(tscreen, ABS_MT_POSITION_Y, pos[i].y);
 		if (ts->chip_info->have_z)
-			input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]);
+			input_report_abs(tscreen, ABS_MT_TOUCH_MAJOR, z[i]);
+	}
+	input_mt_sync_frame(tscreen);
+	input_sync(tscreen);
+
+	if (ts_overlay_mapped_buttons(ts->map)) {
+		for (i = 0; i < ts->chip_info->max_fingers; i++)
+			if (ts_overlay_is_button_slot(ts->map, i) &&
+			    !button_pressed[i])
+				ts_overlay_button_release(ts->map, keypad, i);
+		input_sync(keypad);
 	}
-
-	input_mt_sync_frame(input);
-	input_sync(input);
 
 	return n_contacts;
 }
@@ -226,6 +247,7 @@ static int st1232_ts_probe(struct i2c_client *client)
 	const struct st_chip_info *match;
 	struct st1232_ts_data *ts;
 	struct input_dev *input_dev;
+	struct input_dev __maybe_unused *overlay_keypad;
 	u16 max_x, max_y;
 	int error;
 
@@ -292,18 +314,28 @@ 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 */
+	ts->map = ts_overlay_map_objects(&ts->client->dev, ts->input_dev);
+	if (IS_ERR(ts->map))
+		return PTR_ERR(ts->map);
+
+	if (ts_overlay_mapped_touchscreen(ts->map)) {
+		/* Read resolution from the overlay touchscreen if defined*/
+		ts_overlay_get_touchscreen_abs(ts->map, &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,
@@ -335,6 +367,25 @@ static int st1232_ts_probe(struct i2c_client *client)
 		return error;
 	}
 
+	/* Register keypad input device if overlay buttons were defined */
+	if (ts_overlay_mapped_buttons(ts->map)) {
+		overlay_keypad = devm_input_allocate_device(&client->dev);
+		if (!overlay_keypad)
+			return -ENOMEM;
+
+		ts->overlay_keypad = overlay_keypad;
+		overlay_keypad->name = "st1232-keypad";
+		overlay_keypad->id.bustype = BUS_I2C;
+		ts_overlay_set_button_caps(ts->map, overlay_keypad);
+		error = input_register_device(ts->overlay_keypad);
+		if (error) {
+			dev_err(&client->dev,
+				"Unable to register %s input device\n",
+				overlay_keypad->name);
+			return error;
+		}
+	}
+
 	i2c_set_clientdata(client, ts);
 
 	return 0;

-- 
2.39.2