[PATCH 06/12] Input: synaptics - fuzz position if touchpad reports reduced filtering

djkurtz
2011-06-29T05:09:56Z

From: Daniel Kurtz <djkurtz@chromium.org>

Synaptics touchpads indicate via a capability bit when they perform
reduced filtering on position data.
In such a case, use a non-zero fuzz value.
Fuzz = 8 was chosen empirically by observing the raw position data
reported by a clickpad indicating it had reduced filtering.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
---
drivers/input/mouse/synaptics.c | 17 ++++++++++-------
drivers/input/mouse/synaptics.h | 3 +++
2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index 74b1222..dc54675 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -687,23 +687,27 @@ static psmouse_ret_t synaptics_process_byte(struct psmouse *psmouse)
static void set_input_params(struct input_dev *dev, struct synaptics_data *priv)
{
int i;
+ int fuzz = 0;

__set_bit(INPUT_PROP_POINTER, dev->propbit);

+ if (SYN_CAP_REDUCED_FILTERING(priv->ext_cap_0c))
+ fuzz = SYN_REDUCED_FILTER_FUZZ;
+
__set_bit(EV_ABS, dev->evbit);
- input_set_abs_params(dev, ABS_X,
- XMIN_NOMINAL, priv->x_max ?: XMAX_NOMINAL, 0, 0);
- input_set_abs_params(dev, ABS_Y,
- YMIN_NOMINAL, priv->y_max ?: YMAX_NOMINAL, 0, 0);
+ input_set_abs_params(dev, ABS_X, XMIN_NOMINAL,
+ priv->x_max ?: XMAX_NOMINAL, fuzz, 0);
+ input_set_abs_params(dev, ABS_Y, YMIN_NOMINAL,
+ priv->y_max ?: YMAX_NOMINAL, fuzz, 0);
input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0);

if (SYN_CAP_ADV_GESTURE(priv->ext_cap_0c)) {
__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
input_mt_init_slots(dev, 2);
input_set_abs_params(dev, ABS_MT_POSITION_X, XMIN_NOMINAL,
- priv->x_max ?: XMAX_NOMINAL, 0, 0);
+ priv->x_max ?: XMAX_NOMINAL, fuzz, 0);
input_set_abs_params(dev, ABS_MT_POSITION_Y, YMIN_NOMINAL,
- priv->y_max ?: YMAX_NOMINAL, 0, 0);
+ priv->y_max ?: YMAX_NOMINAL, fuzz, 0);

input_abs_set_res(dev, ABS_MT_POSITION_X, priv->x_res);
input_abs_set_res(dev, ABS_MT_POSITION_Y, priv->y_res);
@@ -977,4 +981,3 @@ bool synaptics_supported(void)
}

#endif /* CONFIG_MOUSE_PS2_SYNAPTICS */
-
diff --git a/drivers/input/mouse/synaptics.h b/drivers/input/mouse/synaptics.h
index 34bedde..8a68e66 100644
--- a/drivers/input/mouse/synaptics.h
+++ b/drivers/input/mouse/synaptics.h
@@ -110,6 +110,9 @@
#define SYN_NEWABS_RELAXED 2
#define SYN_OLDABS 3

+/* amount to fuzz position data when touchpad reports reduced filtering */
+#define SYN_REDUCED_FILTER_FUZZ 8
+
/*
* A structure to describe the state of the touchpad hardware (buttons and pad)
*/
--
1.7.3.1