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@xxxxxxxxxxx>
---
drivers/input/tablet/wacom_wac.c | 10 ++++++++++
drivers/input/tablet/wacom_wac.h | 1 +
2 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
index 97295aa..8193892 100644
--- a/drivers/input/tablet/wacom_wac.c
+++ b/drivers/input/tablet/wacom_wac.c
@@ -858,6 +858,7 @@ static int wacom_tpc_irq(struct wacom_wac *wacom, size_t len)
static int wacom_bpt_irq(struct wacom_wac *wacom, size_t len)
{
static int trkid;
+ 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;
@@ -872,6 +873,10 @@ 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->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;
}
}
diff --git a/drivers/input/tablet/wacom_wac.h b/drivers/input/tablet/wacom_wac.h
index 816ab0f..22cafe2 100644
--- a/drivers/input/tablet/wacom_wac.h
+++ b/drivers/input/tablet/wacom_wac.h
@@ -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
--
1.7.1
--
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