-----Original Message-----
From: Peter Hutterer [mailto:peter.hutterer@who-t.net]
Sent: Sunday, March 29, 2020 10:15 AM
To: Johnny Chuang
Cc: Dmitry Torokhov; Benjamin Tissoires; linux-kernel@vger.kernel.org;
linux-input@vger.kernel.org; Rob Schonberger; Johnny Chuang; James Chen;
Jennifer Tsai; Paul Liang; Jeff Chuang
Subject: Re: [PATCH] Input: elants_i2c - support palm detection

On Thu, Mar 26, 2020 at 03:58:45PM +0800, Johnny Chuang wrote:

quoted

From: Johnny Chuang <redacted>

Elan define finger/palm detection on the least significant bit of byte

33.

quoted

The default value is 1 for all firmwares, which report as

MT_TOOL_FINGER.

quoted

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 <redacted>
---
 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)

quoted

 	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)

quoted

 				i, x, y, p, w);

 			input_mt_slot(input, i);
-			input_mt_report_slot_state(input, MT_TOOL_FINGER,

true);

quoted

+			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

quoted

@@ 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);

quoted

 	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,

quoted

+0);

if you're only reporting pen and palm, can we set this to MT_TOOL_PALM
instead? Otherwise you're indicating you may also send MT_TOOL_DIAL which
is unlikely on this hardware :)

Yes, we do not have MT_TOOL_DIAL on touch screen.
So I need to modify MT_TOOL_MAX to MT_TOOL_PALM, right?

Reviewed-by: Peter Hutterer <redacted> otherwise

Cheers,
   Peter

quoted

 	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