Commit 17c76068 authored by Henrik Rydberg's avatar Henrik Rydberg
Browse files

hid: egalax: Add event filtering 



Use estimated signal-to-noise ratios to reduce noise and limit the
amount of events emitted.

Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
Cc: Stephane Chatty <chatty@enac.fr>
Signed-off-by: default avatarHenrik Rydberg <rydberg@euromail.se>
parent 80a469e4

drivers/hid/hid-egalax.c

+10 −6
Original line number Diff line number Diff line
@@ -25,6 +25,10 @@ MODULE_LICENSE("GPL"); 


#include "hid-ids.h"



/* estimated signal-to-noise ratios */

#define SN_MOVE			4096

#define SN_PRESSURE		32



struct egalax_data {

	__u16 x, y, z;

	__u8 id;
@@ -57,17 +61,17 @@ static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
			field->logical_maximum = 32760;

			hid_map_usage(hi, usage, bit, max,

					EV_ABS, ABS_MT_POSITION_X);

			set_abs(input, ABS_MT_POSITION_X, field, 0);

			set_abs(input, ABS_MT_POSITION_X, field, SN_MOVE);

			/* touchscreen emulation */

			set_abs(input, ABS_X, field, 0);

			set_abs(input, ABS_X, field, SN_MOVE);

			return 1;

		case HID_GD_Y:

			field->logical_maximum = 32760;

			hid_map_usage(hi, usage, bit, max,

					EV_ABS, ABS_MT_POSITION_Y);

			set_abs(input, ABS_MT_POSITION_Y, field, 0);

			set_abs(input, ABS_MT_POSITION_Y, field, SN_MOVE);

			/* touchscreen emulation */

			set_abs(input, ABS_Y, field, 0);

			set_abs(input, ABS_Y, field, SN_MOVE);

			return 1;

		}

		return 0;
@@ -93,9 +97,9 @@ static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
			field->logical_minimum = 0;

			hid_map_usage(hi, usage, bit, max,

					EV_ABS, ABS_MT_PRESSURE);

			set_abs(input, ABS_MT_PRESSURE, field, 0);

			set_abs(input, ABS_MT_PRESSURE, field, SN_PRESSURE);

			/* touchscreen emulation */

			set_abs(input, ABS_PRESSURE, field, 0);

			set_abs(input, ABS_PRESSURE, field, SN_PRESSURE);

			return 1;

		}

		return 0;