[PATCH] Input: elants_i2c - support palm detection

From: Johnny Chuang
Date: Thu Mar 26 2020 - 03:58:54 EST


From: Johnny Chuang <johnny.chuang@xxxxxxxxxx>

Elan define finger/palm detection on the least significant bit of byte 33.
The default value is 1 for all firmwares, which report as MT_TOOL_FINGER.
If firmware support palm detection, the bit will change to 0 and
report as MT_TOOL_PALM when firmware detecting palm.

Signed-off-by: Johnny Chuang <johnny.chuang@xxxxxxxxxx>
---
drivers/input/touchscreen/elants_i2c.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
index 14c577c..3b4d9eb3 100644
--- a/drivers/input/touchscreen/elants_i2c.c
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -73,6 +73,7 @@
#define FW_POS_STATE 1
#define FW_POS_TOTAL 2
#define FW_POS_XY 3
+#define FW_POS_TOOL_TYPE 33
#define FW_POS_CHECKSUM 34
#define FW_POS_WIDTH 35
#define FW_POS_PRESSURE 45
@@ -842,6 +843,7 @@ static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
{
struct input_dev *input = ts->input;
unsigned int n_fingers;
+ unsigned int tool_type;
u16 finger_state;
int i;

@@ -852,6 +854,12 @@ static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
dev_dbg(&ts->client->dev,
"n_fingers: %u, state: %04x\n", n_fingers, finger_state);

+ /* Note: all fingers have the same tool type */
+ if (buf[FW_POS_TOOL_TYPE] & 0x01)
+ tool_type = MT_TOOL_FINGER;
+ else
+ tool_type = MT_TOOL_PALM;
+
for (i = 0; i < MAX_CONTACT_NUM && n_fingers; i++) {
if (finger_state & 1) {
unsigned int x, y, p, w;
@@ -867,7 +875,7 @@ static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
i, x, y, p, w);

input_mt_slot(input, i);
- input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+ input_mt_report_slot_state(input, tool_type, true);
input_event(input, EV_ABS, ABS_MT_POSITION_X, x);
input_event(input, EV_ABS, ABS_MT_POSITION_Y, y);
input_event(input, EV_ABS, ABS_MT_PRESSURE, p);
@@ -1307,6 +1315,7 @@ static int elants_i2c_probe(struct i2c_client *client,
input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, ts->y_max, 0, 0);
input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
+ input_set_abs_params(ts->input, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
input_abs_set_res(ts->input, ABS_MT_TOUCH_MAJOR, 1);
--
2.7.4