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path: root/drivers/mxc/pmic/mc13783/pmic_adc.c
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Diffstat (limited to 'drivers/mxc/pmic/mc13783/pmic_adc.c')
-rw-r--r--drivers/mxc/pmic/mc13783/pmic_adc.c154
1 files changed, 48 insertions, 106 deletions
diff --git a/drivers/mxc/pmic/mc13783/pmic_adc.c b/drivers/mxc/pmic/mc13783/pmic_adc.c
index 5f72f0d43d2a..208087660831 100644
--- a/drivers/mxc/pmic/mc13783/pmic_adc.c
+++ b/drivers/mxc/pmic/mc13783/pmic_adc.c
@@ -231,169 +231,112 @@ static int pmic_adc_filter(t_touch_screen * ts_curr)
{
unsigned int ydiff1, ydiff2, ydiff3, xdiff1, xdiff2, xdiff3;
unsigned int sample_sumx, sample_sumy;
- static unsigned int prev_x[FILTLEN], prev_y[FILTLEN];
- int index = 0;
+ static unsigned int prev_x, prev_y;
unsigned int y_curr, x_curr;
static int filt_count = 0;
- /* Added a variable filt_type to decide filtering at run-time */
- unsigned int filt_type = 0;
+ /* Reset the filter when contact is removed */
if (ts_curr->contact_resistance == 0) {
ts_curr->x_position = 0;
ts_curr->y_position = 0;
filt_count = 0;
+ prev_x = 0;
+ prev_y = 0;
return 0;
}
- ydiff1 = abs(ts_curr->y_position1 - ts_curr->y_position2);
- ydiff2 = abs(ts_curr->y_position2 - ts_curr->y_position3);
- ydiff3 = abs(ts_curr->y_position1 - ts_curr->y_position3);
- if ((ydiff1 > DELTA_Y_MAX) ||
- (ydiff2 > DELTA_Y_MAX) || (ydiff3 > DELTA_Y_MAX)) {
- pr_debug("pmic_adc_filter: Ret pos 1\n");
- return -1;
- }
-
+ /* Compute the differences between the samples */
xdiff1 = abs(ts_curr->x_position1 - ts_curr->x_position2);
xdiff2 = abs(ts_curr->x_position2 - ts_curr->x_position3);
xdiff3 = abs(ts_curr->x_position1 - ts_curr->x_position3);
- if ((xdiff1 > DELTA_X_MAX) ||
- (xdiff2 > DELTA_X_MAX) || (xdiff3 > DELTA_X_MAX)) {
- pr_debug("mc13783_adc_filter: Ret pos 2\n");
- return -1;
- }
- /* Compute two closer values among the three available Y readouts */
+ ydiff1 = abs(ts_curr->y_position1 - ts_curr->y_position2);
+ ydiff2 = abs(ts_curr->y_position2 - ts_curr->y_position3);
+ ydiff3 = abs(ts_curr->y_position1 - ts_curr->y_position3);
+ /*
+ * Compute two closer values among the three available Y
+ * readouts and use the average as the sample
+ */
if (ydiff1 < ydiff2) {
if (ydiff1 < ydiff3) {
- // Sample 0 & 1 closest together
+ // Sample 1 & 2 closest together
sample_sumy = ts_curr->y_position1 +
ts_curr->y_position2;
} else {
- // Sample 0 & 2 closest together
+ // Sample 1 & 3 closest together
sample_sumy = ts_curr->y_position1 +
ts_curr->y_position3;
}
} else {
if (ydiff2 < ydiff3) {
- // Sample 1 & 2 closest together
+ // Sample 2 & 3 closest together
sample_sumy = ts_curr->y_position2 +
ts_curr->y_position3;
} else {
- // Sample 0 & 2 closest together
+ // Sample 1 & 3 closest together
sample_sumy = ts_curr->y_position1 +
ts_curr->y_position3;
}
}
+ sample_sumy /= 2;
/*
* Compute two closer values among the three available X
- * readouts
+ * readouts and use the average as the sample
*/
if (xdiff1 < xdiff2) {
if (xdiff1 < xdiff3) {
- // Sample 0 & 1 closest together
+ // Sample 1 & 2 closest together
sample_sumx = ts_curr->x_position1 +
ts_curr->x_position2;
} else {
- // Sample 0 & 2 closest together
+ // Sample 1 & 3 closest together
sample_sumx = ts_curr->x_position1 +
ts_curr->x_position3;
}
} else {
if (xdiff2 < xdiff3) {
- // Sample 1 & 2 closest together
+ // Sample 2 & 3 closest together
sample_sumx = ts_curr->x_position2 +
ts_curr->x_position3;
} else {
- // Sample 0 & 2 closest together
+ // Sample 1 & 3 closest together
sample_sumx = ts_curr->x_position1 +
ts_curr->x_position3;
}
}
+ sample_sumx /= 2;
+
/*
- * Wait FILTER_MIN_DELAY number of samples to restart
- * filtering
+ * Current output is a simple low pass filter
+ * based on previous and current value.
*/
- if (filt_count < FILTER_MIN_DELAY) {
- /*
- * Current output is the average of the two closer
- * values and no filtering is used
- */
- y_curr = (sample_sumy / 2);
- x_curr = (sample_sumx / 2);
- ts_curr->y_position = y_curr;
- ts_curr->x_position = x_curr;
- filt_count++;
- } else {
- if (abs(sample_sumx - (prev_x[0] + prev_x[1])) >
- (DELTA_X_MAX * 16)) {
- pr_debug("pmic_adc_filter: : Ret pos 3\n");
- return -1;
- }
- if (abs(sample_sumy - (prev_y[0] + prev_y[1])) >
- (DELTA_Y_MAX * 16)) {
- return -1;
- }
- sample_sumy /= 2;
- sample_sumx /= 2;
- /* Use hard filtering if the sample difference < 10 */
- if ((abs(sample_sumy - prev_y[0]) > 10) ||
- (abs(sample_sumx - prev_x[0]) > 10)) {
- filt_type = 1;
- }
+ /* Y Filter */
+ y_curr = ((sample_sumy * 90) + (prev_y * 10))/100;
+ ts_curr->y_position = y_curr;
- /*
- * Current outputs are the average of three previous
- * values and the present readout
- */
- y_curr = sample_sumy;
- for (index = 0; index < FILTLEN; index++) {
- if (filt_type == 0) {
- y_curr = y_curr + (prev_y[index]);
- } else {
- y_curr = y_curr + (prev_y[index] / 3);
- }
- }
- if (filt_type == 0) {
- y_curr = y_curr >> 2;
- } else {
- y_curr = y_curr >> 1;
- }
- ts_curr->y_position = y_curr;
-
- x_curr = sample_sumx;
- for (index = 0; index < FILTLEN; index++) {
- if (filt_type == 0) {
- x_curr = x_curr + (prev_x[index]);
- } else {
- x_curr = x_curr + (prev_x[index] / 3);
- }
- }
- if (filt_type == 0) {
- x_curr = x_curr >> 2;
- } else {
- x_curr = x_curr >> 1;
- }
- ts_curr->x_position = x_curr;
-
- }
-
- /* Update previous X and Y values */
- for (index = (FILTLEN - 1); index > 0; index--) {
- prev_x[index] = prev_x[index - 1];
- prev_y[index] = prev_y[index - 1];
- }
+ /* X Filter */
+ x_curr = ((sample_sumx * 90) + (prev_x * 10))/100;
+ ts_curr->x_position = x_curr;
/*
- * Current output will be the most recent past for the
- * next sample
+ * Store current sample for next evaluation
*/
- prev_y[0] = y_curr;
- prev_x[0] = x_curr;
+ prev_y = y_curr;
+ prev_x = x_curr;
- return 0;
+ /*
+ * Wait FILTER_MIN_DELAY number of samples to restart
+ * filtering. This is used to seed the filter until it
+ * has enough samples to be stable.
+ */
+ if (filt_count < FILTER_MIN_DELAY) {
+ filt_count++;
+ return -1;
+ } else {
+ return 0;
+ }
}
/*!
@@ -687,7 +630,6 @@ PMIC_STATUS mc13783_adc_convert(t_adc_param * adc_param)
adc_param->ts_value.y_position3 = adc_param->value[5];
adc_param->ts_value.y_position = adc_param->value[5];
adc_param->ts_value.contact_resistance = adc_param->value[6];
-
}
/*if (adc_param->read_ts) {
@@ -936,8 +878,8 @@ PMIC_STATUS pmic_adc_get_touch_mode(t_touch_mode * touch_mode)
PMIC_STATUS pmic_adc_get_touch_sample(t_touch_screen * touch_sample, int wait)
{
mc13783_adc_read_ts(touch_sample, wait);
- pmic_adc_filter(touch_sample);
- return PMIC_SUCCESS;
+
+ return pmic_adc_filter(touch_sample);
}
/*!
generated by cgit v1.2.3 (git 2.0.4) at 2024-05-12 15:09:33 +0000