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: Henrik Rydberg <rydberg@euromail.se>
Acked-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
index 4e9b1dd..2f4411a 100644
--- a/drivers/input/tablet/wacom_wac.c
+++ b/drivers/input/tablet/wacom_wac.c
@@ -857,6 +857,7 @@
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 @@
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 @@
/* 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;
}
}