+++ /dev/null
-/*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * Copyright (c) 2008 Andy Green <andy@openmoko.com>
- *
- *
- * Median averaging stuff. We sort incoming raw samples into an array of
- * MEDIAN_SIZE length, discarding the oldest sample each time once we are full.
- * We then return the sum of the middle three samples for X and Y. It means
- * the final result must be divided by (3 * scaling factor) to correct for
- * avoiding the repeated /3.
- *
- * This strongly rejects brief excursions away from a central point that is
- * sticky in time compared to the excursion duration.
- *
- * Thanks to Dale Schumacher (who wrote some example code) and Carl-Daniel
- * Halifinger who pointed out this would be a good method.
- */
-
-#include <linux/errno.h>
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <linux/touchscreen/ts_filter_median.h>
-
-struct ts_filter_median {
- /* Private configuration. */
- struct ts_filter_median_configuration *config;
- /* Generic Filter API. */
- struct ts_filter tsf;
-
- /* Count raw samples we get. */
- int samples_count;
- /*
- * Remember the last coordinates we got in order to know if
- * we are moving slow or fast.
- */
- int last_issued[MAX_TS_FILTER_COORDS];
- /* How many samples in the sort buffer are valid. */
- int valid;
- /* Samples taken for median in sorted form. */
- int *sort[MAX_TS_FILTER_COORDS];
- /* Samples taken for median. */
- int *fifo[MAX_TS_FILTER_COORDS];
- /* Where we are in the fifo sample memory. */
- int pos;
- /* Do we have a sample to deliver? */
- int ready;
-};
-
-#define ts_filter_to_filter_median(f) \
- container_of(f, struct ts_filter_median, tsf)
-
-
-static void ts_filter_median_insert(int *p, int sample, int count)
-{
- int n;
-
- /* Search through what we got so far to find where to put sample. */
- for (n = 0; n < count; n++)
- if (sample < p[n]) { /* We met somebody bigger than us? */
- /* Starting from the end, push bigger guys down one. */
- for (count--; count >= n; count--)
- p[count + 1] = p[count];
- p[n] = sample; /* Put us in place of first bigger. */
- return;
- }
-
- p[count] = sample; /* Nobody was bigger than us, add us on the end. */
-}
-
-static void ts_filter_median_del(int *p, int value, int count)
-{
- int index;
-
- for (index = 0; index < count; index++)
- if (p[index] == value) {
- for (; index < count; index++)
- p[index] = p[index + 1];
- return;
- }
-}
-
-
-static void ts_filter_median_clear(struct ts_filter *tsf)
-{
- struct ts_filter_median *tsfm = ts_filter_to_filter_median(tsf);
-
- tsfm->pos = 0;
- tsfm->valid = 0;
- tsfm->ready = 0;
- memset(&tsfm->last_issued[0], 1, tsf->count_coords * sizeof(int));
-}
-
-static struct ts_filter *ts_filter_median_create(
- struct platform_device *pdev,
- const struct ts_filter_configuration *conf,
- int count_coords)
-{
- int *p;
- int n;
- struct ts_filter_median *tsfm = kzalloc(sizeof(struct ts_filter_median),
- GFP_KERNEL);
-
- if (!tsfm)
- return NULL;
-
- tsfm->config = container_of(conf,
- struct ts_filter_median_configuration,
- config);
-
- tsfm->tsf.count_coords = count_coords;
-
- tsfm->config->midpoint = (tsfm->config->extent >> 1) + 1;
-
- p = kmalloc(2 * count_coords * sizeof(int) * (tsfm->config->extent + 1),
- GFP_KERNEL);
- if (!p) {
- kfree(tsfm);
- return NULL;
- }
-
- for (n = 0; n < count_coords; n++) {
- tsfm->sort[n] = p;
- p += tsfm->config->extent + 1;
- tsfm->fifo[n] = p;
- p += tsfm->config->extent + 1;
- }
-
- ts_filter_median_clear(&tsfm->tsf);
-
- dev_info(&pdev->dev,
- "Created Median filter len:%d coords:%d dec_threshold:%d\n",
- tsfm->config->extent, count_coords,
- tsfm->config->decimation_threshold);
-
- return &tsfm->tsf;
-}
-
-static void ts_filter_median_destroy(struct ts_filter *tsf)
-{
- struct ts_filter_median *tsfm = ts_filter_to_filter_median(tsf);
-
- kfree(tsfm->sort[0]); /* First guy has pointer from kmalloc. */
- kfree(tsf);
-}
-
-static void ts_filter_median_scale(struct ts_filter *tsf, int *coords)
-{
- int n;
-
- for (n = 0; n < tsf->count_coords; n++)
- coords[n] = (coords[n] + 2) / 3;
-}
-
-/*
- * Give us the raw sample data coords, and if we return 1 then you can
- * get a filtered coordinate from coords. If we return 0 you didn't
- * fill all the filters with samples yet.
- */
-
-static int ts_filter_median_process(struct ts_filter *tsf, int *coords)
-{
- struct ts_filter_median *tsfm = ts_filter_to_filter_median(tsf);
- int n;
- int movement = 1;
-
- for (n = 0; n < tsf->count_coords; n++) {
- /* Grab copy in insertion order to remove when oldest. */
- tsfm->fifo[n][tsfm->pos] = coords[n];
- /* Insert these samples in sorted order in the median arrays. */
- ts_filter_median_insert(tsfm->sort[n], coords[n], tsfm->valid);
- }
- /* Move us on in the fifo. */
- if (++tsfm->pos == (tsfm->config->extent + 1))
- tsfm->pos = 0;
-
- /* Have we finished a median sampling? */
- if (++tsfm->valid < tsfm->config->extent)
- goto process_exit; /* No valid sample to use. */
-
- BUG_ON(tsfm->valid != tsfm->config->extent);
-
- tsfm->valid--;
-
- /*
- * Sum the middle 3 in the median sorted arrays. We don't divide back
- * down which increases the sum resolution by a factor of 3 until the
- * scale API function is called.
- */
- for (n = 0; n < tsf->count_coords; n++)
- /* Perform the deletion of the oldest sample. */
- ts_filter_median_del(tsfm->sort[n], tsfm->fifo[n][tsfm->pos],
- tsfm->valid);
-
- tsfm->samples_count--;
- if (tsfm->samples_count >= 0)
- goto process_exit;
-
- for (n = 0; n < tsf->count_coords; n++) {
- /* Give the coordinate result from summing median 3. */
- coords[n] = tsfm->sort[n][tsfm->config->midpoint - 1] +
- tsfm->sort[n][tsfm->config->midpoint] +
- tsfm->sort[n][tsfm->config->midpoint + 1];
-
- movement += abs(tsfm->last_issued[n] - coords[n]);
- }
-
- if (movement > tsfm->config->decimation_threshold) /* Moving fast. */
- tsfm->samples_count = tsfm->config->decimation_above;
- else
- tsfm->samples_count = tsfm->config->decimation_below;
-
- memcpy(&tsfm->last_issued[0], coords, tsf->count_coords * sizeof(int));
-
- tsfm->ready = 1;
-
-process_exit:
- return 0;
-}
-
-static int ts_filter_median_haspoint(struct ts_filter *tsf)
-{
- struct ts_filter_median *priv = ts_filter_to_filter_median(tsf);
-
- return priv->ready;
-}
-
-static void ts_filter_median_getpoint(struct ts_filter *tsf, int *point)
-{
- struct ts_filter_median *priv = ts_filter_to_filter_median(tsf);
-
- BUG_ON(!priv->ready);
-
- memcpy(point, &priv->last_issued[0], tsf->count_coords * sizeof(int));
-
- priv->ready = 0;
-}
-
-const struct ts_filter_api ts_filter_median_api = {
- .create = ts_filter_median_create,
- .destroy = ts_filter_median_destroy,
- .clear = ts_filter_median_clear,
- .process = ts_filter_median_process,
- .scale = ts_filter_median_scale,
- .haspoint = ts_filter_median_haspoint,
- .getpoint = ts_filter_median_getpoint,
-};
-EXPORT_SYMBOL_GPL(ts_filter_median_api);
-
projects / openwrt / svn-archive / archive.git / blobdiff