Commit f27ad893 authored by Johnny Chuang's avatar Johnny Chuang Committed by Dmitry Torokhov
Browse files

Input: elants_i2c - support palm detection 



Elan uses the least significant bit of byte 33 to signal the type of
contact (finger versus palm). The default value is 1 for all firmwares,
which is reported as MT_TOOL_FINGER. If firmware supports palm detection,
the bit will change to 0 and the driver will report such contact as
MT_TOOL_PALM.

Signed-off-by: default avatarJohnny Chuang <johnny.chuang@emc.com.tw>
Reviewed-by: default avatarPeter Hutterer <peter.hutterer@who-t.net>
Link: https://lore.kernel.org/r/1585551756-29066-1-git-send-email-johnny.chuang.emc@gmail.com


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent cd510679

drivers/input/touchscreen/elants_i2c.c

+10 −1
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
 */





#include <linux/bits.h>

#include <linux/module.h>

#include <linux/input.h>

#include <linux/interrupt.h>
@@ -73,6 +74,7 @@ 
#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 +844,7 @@ 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 +855,10 @@ 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 */

	tool_type = buf[FW_POS_TOOL_TYPE] & BIT(0) ?

			MT_TOOL_FINGER : 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 +874,7 @@ 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 +1314,8 @@ 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_PALM, 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);