[PATCH v8 4/4] Input: st1232 - add touch overlays handling

From: Javier Carrasco
Date: Wed Mar 20 2024 - 04:01:17 EST


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

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.

Reviewed-by: Jeff LaBundy <jeff@xxxxxxxxxxx>
Signed-off-by: Javier Carrasco <javier.carrasco@xxxxxxxxxxxxxx>
---
drivers/input/touchscreen/st1232.c | 48 +++++++++++++++++++++++++++-----------
1 file changed, 34 insertions(+), 14 deletions(-)

diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index 6475084aee1b..4fa31447dbc1 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/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;
};
@@ -138,14 +140,20 @@ static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)

for (i = 0; i < ts->chip_info->max_fingers; i++) {
u8 *buf = &ts->read_buf[i * 4];
+ bool contact = buf[0] & BIT(7);
+ unsigned int x, y;

- if (buf[0] & BIT(7)) {
- unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
- unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
-
- touchscreen_set_mt_pos(&pos[n_contacts],
- &ts->prop, x, y);
+ if (contact) {
+ x = ((buf[0] & 0x70) << 4) | buf[1];
+ y = ((buf[0] & 0x07) << 8) | buf[2];
+ }
+ if (touch_overlay_process_event(&ts->touch_overlay_list, input,
+ contact ? &x : NULL,
+ contact ? &y : NULL, i))
+ continue;

+ if (contact) {
+ touchscreen_set_mt_pos(&pos[n_contacts], &ts->prop, x, y);
/* st1232 includes a z-axis / touch strength */
if (ts->chip_info->have_z)
z[n_contacts] = ts->read_buf[i + 6];
@@ -292,18 +300,30 @@ 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,

--
2.40.1