Commit f4ccbef2 authored by Henrik Rydberg's avatar Henrik Rydberg Committed by Dmitry Torokhov
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Input: wacom - add a quirk for low resolution Bamboo devices 



The Bamboo Touch reports a sub-screen resolution of 480x320.  The
signal-to-noise ratio is only about 100, so filtering is needed in
order to reduce the jitter to a usable level. However, the low
resolution leads to round-off errors in the EWMA filter, resulting in
extremely jerky pointer motion. This patch explicitly sets a higher
resolution for those devices, and tells this to the completion handler
via a low-resolution quirk.

Signed-off-by: default avatarHenrik Rydberg <rydberg@euromail.se>
Acked-by: default avatarPing Cheng <pingc@wacom.com>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent cb734c03

drivers/input/tablet/wacom_wac.c

+10 −0
Original line number Diff line number Diff line
@@ -857,6 +857,7 @@ static int wacom_tpc_irq(struct wacom_wac *wacom, size_t len) 


static int wacom_bpt_irq(struct wacom_wac *wacom, size_t len)

{

	struct wacom_features *features = &wacom->features;

	struct input_dev *input = wacom->input;

	unsigned char *data = wacom->data;

	int sp = 0, sx = 0, sy = 0, count = 0;
@@ -871,6 +872,10 @@ static int wacom_bpt_irq(struct wacom_wac *wacom, size_t len) 
		if (p) {

			int x = get_unaligned_be16(&data[9 * i + 3]) & 0x7ff;

			int y = get_unaligned_be16(&data[9 * i + 5]) & 0x7ff;

			if (features->quirks & WACOM_QUIRK_BBTOUCH_LOWRES) {

				x <<= 5;

				y <<= 5;

			}

			input_report_abs(input, ABS_MT_PRESSURE, p);

			input_report_abs(input, ABS_MT_POSITION_X, x);

			input_report_abs(input, ABS_MT_POSITION_Y, y);
@@ -1010,8 +1015,13 @@ void wacom_setup_device_quirks(struct wacom_features *features) 
	/* quirks for bamboo touch */

	if (features->type == BAMBOO_PT &&

	    features->device_type == BTN_TOOL_TRIPLETAP) {

		features->x_max <<= 5;

		features->y_max <<= 5;

		features->x_fuzz <<= 5;

		features->y_fuzz <<= 5;

		features->pressure_max = 256;

		features->pressure_fuzz = 16;

		features->quirks |= WACOM_QUIRK_BBTOUCH_LOWRES;

	}

}

drivers/input/tablet/wacom_wac.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 


/* device quirks */

#define WACOM_QUIRK_MULTI_INPUT		0x0001

#define WACOM_QUIRK_BBTOUCH_LOWRES	0x0002



/* largest reported tracking id */

#define MAX_TRACKING_ID			0xfff

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