HID: wacom: Add fuzz factor to distance and tilt axes

Commit Message

Gerecke, Jason April 25, 2016, 6:27 p.m. UTC

The fuzz present on the distance and tilt axes is noticable when a puck is
present, and userspace (specifically libinput) would like the ability to
filter out the noise. To facilitate this, we assign a fuzz value of '1'
for the distance and tilt axes. This is large enough to cover most of the
natural variation in distance value as the puck is moved around, and
enough to cover the jitter in rotation (reported through tilt axes) when
the puck is left alone.

Signed-off-by: Jason Gerecke <[e-mail]>
---
Apologies for attaching rather than inlining the patch. I'm stuck with
using GMail's web interface instead of 'git-send-email' or a real
client at the moment...

Comments

Jiri Kosina May 3, 2016, 9:57 a.m. UTC | #1

On Mon, 25 Apr 2016, Jason Gerecke wrote:

> The fuzz present on the distance and tilt axes is noticable when a puck is
> present, and userspace (specifically libinput) would like the ability to
> filter out the noise. To facilitate this, we assign a fuzz value of '1'
> for the distance and tilt axes. This is large enough to cover most of the
> natural variation in distance value as the puck is moved around, and
> enough to cover the jitter in rotation (reported through tilt axes) when
> the puck is left alone.

Applied to for-4.7/wacom.

Patch

From a2aa9d04d6918169fd0fbf29bf7cf9e172320844 Mon Sep 17 00:00:00 2001
From: Jason Gerecke <[e-mail]>
Date: Fri, 22 Apr 2016 14:30:53 -0700
Subject: [PATCH] HID: wacom: Add fuzz factor to distance and tilt axes

The fuzz present on the distance and tilt axes is noticable when a puck is
present, and userspace (specifically libinput) would like the ability to
filter out the noise. To facilitate this, we assign a fuzz value of '1'
for the distance and tilt axes. This is large enough to cover most of the
natural variation in distance value as the puck is moved around, and
enough to cover the jitter in rotation (reported through tilt axes) when
the puck is left alone.

Signed-off-by: Jason Gerecke <[e-mail]>
---
 drivers/hid/wacom_sys.c |  3 ++-
 drivers/hid/wacom_wac.c | 13 +++++++------
 drivers/hid/wacom_wac.h |  1 +
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index ccf1883..499cc82 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -493,7 +493,8 @@  static void wacom_retrieve_hid_descriptor(struct hid_device *hdev,
 	features->x_fuzz = 4;
 	features->y_fuzz = 4;
 	features->pressure_fuzz = 0;
-	features->distance_fuzz = 0;
+	features->distance_fuzz = 1;
+	features->tilt_fuzz = 1;
 
 	/*
 	 * The wireless device HID is basic and layout conflicts with
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index e9902f2..25fdd97 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -2343,12 +2343,13 @@  static void wacom_setup_basic_pro_pen(struct wacom_wac *wacom_wac)
 	__set_bit(BTN_STYLUS2, input_dev->keybit);
 
 	input_set_abs_params(input_dev, ABS_DISTANCE,
-			     0, wacom_wac->features.distance_max, 0, 0);
+			     0, wacom_wac->features.distance_max, wacom_wac->features.distance_fuzz, 0);
 }
 
 static void wacom_setup_cintiq(struct wacom_wac *wacom_wac)
 {
 	struct input_dev *input_dev = wacom_wac->pen_input;
+	struct wacom_features *features = &wacom_wac->features;
 
 	wacom_setup_basic_pro_pen(wacom_wac);
 
@@ -2358,9 +2359,9 @@  static void wacom_setup_cintiq(struct wacom_wac *wacom_wac)
 	__set_bit(BTN_TOOL_AIRBRUSH, input_dev->keybit);
 
 	input_set_abs_params(input_dev, ABS_WHEEL, 0, 1023, 0, 0);
-	input_set_abs_params(input_dev, ABS_TILT_X, -64, 63, 0, 0);
+	input_set_abs_params(input_dev, ABS_TILT_X, -64, 63, features->tilt_fuzz, 0);
 	input_abs_set_res(input_dev, ABS_TILT_X, 57);
-	input_set_abs_params(input_dev, ABS_TILT_Y, -64, 63, 0, 0);
+	input_set_abs_params(input_dev, ABS_TILT_Y, -64, 63, features->tilt_fuzz, 0);
 	input_abs_set_res(input_dev, ABS_TILT_Y, 57);
 }
 
@@ -2506,7 +2507,7 @@  int wacom_setup_pen_input_capabilities(struct input_dev *input_dev,
 	case WACOM_G4:
 		input_set_abs_params(input_dev, ABS_DISTANCE, 0,
 					      features->distance_max,
-					      0, 0);
+					      features->distance_fuzz, 0);
 		/* fall through */
 
 	case GRAPHIRE:
@@ -2568,7 +2569,7 @@  int wacom_setup_pen_input_capabilities(struct input_dev *input_dev,
 
 		input_set_abs_params(input_dev, ABS_DISTANCE, 0,
 				      features->distance_max,
-				      0, 0);
+				      features->distance_fuzz, 0);
 
 		input_set_abs_params(input_dev, ABS_Z, -900, 899, 0, 0);
 		input_abs_set_res(input_dev, ABS_Z, 287);
@@ -2627,7 +2628,7 @@  int wacom_setup_pen_input_capabilities(struct input_dev *input_dev,
 			__set_bit(BTN_STYLUS2, input_dev->keybit);
 			input_set_abs_params(input_dev, ABS_DISTANCE, 0,
 				      features->distance_max,
-				      0, 0);
+				      features->distance_fuzz, 0);
 		}
 		break;
 	case BAMBOO_PAD:
diff --git a/drivers/hid/wacom_wac.h b/drivers/hid/wacom_wac.h
index e2084d9..53d1653 100644
--- a/drivers/hid/wacom_wac.h
+++ b/drivers/hid/wacom_wac.h
@@ -177,6 +177,7 @@  struct wacom_features {
 	int y_fuzz;
 	int pressure_fuzz;
 	int distance_fuzz;
+	int tilt_fuzz;
 	unsigned quirks;
 	unsigned touch_max;
 	int oVid;
-- 
2.8.0