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-rw-r--r--drivers/input/mouse/appletouch.c103
1 files changed, 79 insertions, 24 deletions
diff --git a/drivers/input/mouse/appletouch.c b/drivers/input/mouse/appletouch.c
index 2745832f74b6..2dbf7a0f0537 100644
--- a/drivers/input/mouse/appletouch.c
+++ b/drivers/input/mouse/appletouch.c
@@ -161,6 +161,12 @@ MODULE_DEVICE_TABLE(usb, atp_table);
#define ATP_XSENSORS 26
#define ATP_YSENSORS 16
+/*
+ * The largest possible bank of sensors with additional buffer of 4 extra values
+ * on either side, for an array of smoothed sensor values.
+ */
+#define ATP_SMOOTHSIZE 34
+
/* maximum pressure this driver will report */
#define ATP_PRESSURE 300
@@ -168,7 +174,13 @@ MODULE_DEVICE_TABLE(usb, atp_table);
* Threshold for the touchpad sensors. Any change less than ATP_THRESHOLD is
* ignored.
*/
-#define ATP_THRESHOLD 5
+#define ATP_THRESHOLD 5
+
+/*
+ * How far we'll bitshift our sensor values before averaging them. Mitigates
+ * rounding errors.
+ */
+#define ATP_SCALE 12
/* Geyser initialization constants */
#define ATP_GEYSER_MODE_READ_REQUEST_ID 1
@@ -211,6 +223,8 @@ struct atp {
signed char xy_cur[ATP_XSENSORS + ATP_YSENSORS];
signed char xy_old[ATP_XSENSORS + ATP_YSENSORS];
int xy_acc[ATP_XSENSORS + ATP_YSENSORS];
+ int smooth[ATP_SMOOTHSIZE];
+ int smooth_tmp[ATP_SMOOTHSIZE];
int idlecount; /* number of empty packets */
struct work_struct work;
};
@@ -329,10 +343,17 @@ static void atp_reinit(struct work_struct *work)
retval);
}
-static int atp_calculate_abs(int *xy_sensors, int nb_sensors, int fact,
- int *z, int *fingers)
+static int atp_calculate_abs(struct atp *dev, int offset, int nb_sensors,
+ int fact, int *z, int *fingers)
{
- int i;
+ int i, pass;
+
+ /*
+ * Use offset to point xy_sensors at the first value in dev->xy_acc
+ * for whichever dimension we're looking at this particular go-round.
+ */
+ int *xy_sensors = dev->xy_acc + offset;
+
/* values to calculate mean */
int pcum = 0, psum = 0;
int is_increasing = 0;
@@ -344,9 +365,6 @@ static int atp_calculate_abs(int *xy_sensors, int nb_sensors, int fact,
if (is_increasing)
is_increasing = 0;
- continue;
- }
-
/*
* Makes the finger detection more versatile. For example,
* two fingers with no gap will be detected. Also, my
@@ -361,27 +379,63 @@ static int atp_calculate_abs(int *xy_sensors, int nb_sensors, int fact,
*
* - Jason Parekh <jasonparekh@gmail.com>
*/
- if (i < 1 ||
+
+ } else if (i < 1 ||
(!is_increasing && xy_sensors[i - 1] < xy_sensors[i])) {
(*fingers)++;
is_increasing = 1;
} else if (i > 0 && (xy_sensors[i - 1] - xy_sensors[i] > threshold)) {
is_increasing = 0;
}
+ }
+
+ if (*fingers < 1) /* No need to continue if no fingers are found. */
+ return 0;
+
+ /*
+ * Use a smoothed version of sensor data for movement calculations, to
+ * combat noise without needing to rely so heavily on a threshold.
+ * This improves tracking.
+ *
+ * The smoothed array is bigger than the original so that the smoothing
+ * doesn't result in edge values being truncated.
+ */
+
+ memset(dev->smooth, 0, 4 * sizeof(dev->smooth[0]));
+ /* Pull base values, scaled up to help avoid truncation errors. */
+ for (i = 0; i < nb_sensors; i++)
+ dev->smooth[i + 4] = xy_sensors[i] << ATP_SCALE;
+ memset(&dev->smooth[nb_sensors + 4], 0, 4 * sizeof(dev->smooth[0]));
+ for (pass = 0; pass < 4; pass++) {
+ /* Handle edge. */
+ dev->smooth_tmp[0] = (dev->smooth[0] + dev->smooth[1]) / 2;
+
+ /* Average values with neighbors. */
+ for (i = 1; i < nb_sensors + 7; i++)
+ dev->smooth_tmp[i] = (dev->smooth[i - 1] +
+ dev->smooth[i] * 2 +
+ dev->smooth[i + 1]) / 4;
+
+ /* Handle other edge. */
+ dev->smooth_tmp[i] = (dev->smooth[i - 1] + dev->smooth[i]) / 2;
+
+ memcpy(dev->smooth, dev->smooth_tmp, sizeof(dev->smooth));
+ }
+
+ for (i = 0; i < nb_sensors + 8; i++) {
/*
- * Subtracts threshold so a high sensor that just passes the
- * threshold won't skew the calculated absolute coordinate.
- * Fixes an issue where slowly moving the mouse would
- * occasionally jump a number of pixels (slowly moving the
- * finger makes this issue most apparent.)
+ * Skip values if they're small enough to be truncated to 0
+ * by scale. Mostly noise.
*/
- pcum += (xy_sensors[i] - threshold) * i;
- psum += (xy_sensors[i] - threshold);
+ if ((dev->smooth[i] >> ATP_SCALE) > 0) {
+ pcum += dev->smooth[i] * i;
+ psum += dev->smooth[i];
+ }
}
if (psum > 0) {
- *z = psum;
+ *z = psum >> ATP_SCALE; /* Scale down pressure output. */
return pcum * fact / psum;
}
@@ -551,16 +605,16 @@ static void atp_complete_geyser_1_2(struct urb *urb)
dbg_dump("accumulator", dev->xy_acc);
- x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
+ x = atp_calculate_abs(dev, 0, ATP_XSENSORS,
dev->info->xfact, &x_z, &x_f);
- y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
+ y = atp_calculate_abs(dev, ATP_XSENSORS, ATP_YSENSORS,
dev->info->yfact, &y_z, &y_f);
key = dev->data[dev->info->datalen - 1] & ATP_STATUS_BUTTON;
if (x && y) {
if (dev->x_old != -1) {
- x = (dev->x_old * 3 + x) >> 2;
- y = (dev->y_old * 3 + y) >> 2;
+ x = (dev->x_old * 7 + x) >> 3;
+ y = (dev->y_old * 7 + y) >> 3;
dev->x_old = x;
dev->y_old = y;
@@ -663,16 +717,17 @@ static void atp_complete_geyser_3_4(struct urb *urb)
dbg_dump("accumulator", dev->xy_acc);
- x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
+ x = atp_calculate_abs(dev, 0, ATP_XSENSORS,
dev->info->xfact, &x_z, &x_f);
- y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
+ y = atp_calculate_abs(dev, ATP_XSENSORS, ATP_YSENSORS,
dev->info->yfact, &y_z, &y_f);
+
key = dev->data[dev->info->datalen - 1] & ATP_STATUS_BUTTON;
if (x && y) {
if (dev->x_old != -1) {
- x = (dev->x_old * 3 + x) >> 2;
- y = (dev->y_old * 3 + y) >> 2;
+ x = (dev->x_old * 7 + x) >> 3;
+ y = (dev->y_old * 7 + y) >> 3;
dev->x_old = x;
dev->y_old = y;
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-27 10:54:22 +0300