hid: egalax: Add event filtering

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

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Stephane Chatty <chatty@enac.fr>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
This commit is contained in:
Henrik Rydberg 2010-10-11 21:20:51 +02:00
parent 80a469e4f4
commit 17c760687f

View file

@ -25,6 +25,10 @@ MODULE_LICENSE("GPL");
#include "hid-ids.h" #include "hid-ids.h"
/* estimated signal-to-noise ratios */
#define SN_MOVE 4096
#define SN_PRESSURE 32
struct egalax_data { struct egalax_data {
__u16 x, y, z; __u16 x, y, z;
__u8 id; __u8 id;
@ -57,17 +61,17 @@ static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi,
field->logical_maximum = 32760; field->logical_maximum = 32760;
hid_map_usage(hi, usage, bit, max, hid_map_usage(hi, usage, bit, max,
EV_ABS, ABS_MT_POSITION_X); 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 */ /* touchscreen emulation */
set_abs(input, ABS_X, field, 0); set_abs(input, ABS_X, field, SN_MOVE);
return 1; return 1;
case HID_GD_Y: case HID_GD_Y:
field->logical_maximum = 32760; field->logical_maximum = 32760;
hid_map_usage(hi, usage, bit, max, hid_map_usage(hi, usage, bit, max,
EV_ABS, ABS_MT_POSITION_Y); 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 */ /* touchscreen emulation */
set_abs(input, ABS_Y, field, 0); set_abs(input, ABS_Y, field, SN_MOVE);
return 1; return 1;
} }
return 0; return 0;
@ -93,9 +97,9 @@ static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi,
field->logical_minimum = 0; field->logical_minimum = 0;
hid_map_usage(hi, usage, bit, max, hid_map_usage(hi, usage, bit, max,
EV_ABS, ABS_MT_PRESSURE); EV_ABS, ABS_MT_PRESSURE);
set_abs(input, ABS_MT_PRESSURE, field, 0); set_abs(input, ABS_MT_PRESSURE, field, SN_PRESSURE);
/* touchscreen emulation */ /* touchscreen emulation */
set_abs(input, ABS_PRESSURE, field, 0); set_abs(input, ABS_PRESSURE, field, SN_PRESSURE);
return 1; return 1;
} }
return 0; return 0;