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authorNelson Castillo <arhuaco@freaks-unidos.net>2009-10-24 03:04:31 -0500
committerLars-Peter Clausen <lars@metafoo.de>2009-12-15 18:30:22 +0100
commit9c015a908586a923406b025f51c5dc3896e530a7 (patch)
treeaa96d1d9c01b835b6a144abe42270e32278a4812 /drivers
parentfb49c8b3238fec0f79535303e90e909ccc058059 (diff)
Add touchscreen filters
Add filter source code and add it to the defconfig. Signed-off-by: Nelson Castillo <arhuaco@freaks-unidos.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/input/touchscreen/Kconfig44
-rw-r--r--drivers/input/touchscreen/Makefile5
-rw-r--r--drivers/input/touchscreen/ts_filter.h74
-rw-r--r--drivers/input/touchscreen/ts_filter_chain.c183
-rw-r--r--drivers/input/touchscreen/ts_filter_chain.h58
-rw-r--r--drivers/input/touchscreen/ts_filter_group.c330
-rw-r--r--drivers/input/touchscreen/ts_filter_group.h36
-rw-r--r--drivers/input/touchscreen/ts_filter_linear.c212
-rw-r--r--drivers/input/touchscreen/ts_filter_linear.h31
-rw-r--r--drivers/input/touchscreen/ts_filter_mean.c174
-rw-r--r--drivers/input/touchscreen/ts_filter_mean.h28
-rw-r--r--drivers/input/touchscreen/ts_filter_median.c261
-rw-r--r--drivers/input/touchscreen/ts_filter_median.h32
13 files changed, 1468 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 8cc453c85ea..faf929e5454 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -11,6 +11,50 @@ menuconfig INPUT_TOUCHSCREEN
if INPUT_TOUCHSCREEN
+menuconfig TOUCHSCREEN_FILTER
+ boolean "Touchscreen Filtering"
+ depends on INPUT_TOUCHSCREEN
+ select TOUCHSCREEN_FILTER_GROUP
+ select TOUCHSCREEN_FILTER_MEDIAN
+ select TOUCHSCREEN_FILTER_MEAN
+ select TOUCHSCREEN_FILTER_LINEAR
+ help
+ Select this to include kernel touchscreen filter support. The filters
+ can be combined in any order in your machine init and the parameters
+ for them can also be set there.
+
+config TOUCHSCREEN_FILTER_GROUP
+ bool "Group Touchscreen Filter"
+ depends on INPUT_TOUCHSCREEN && TOUCHSCREEN_FILTER
+ default Y
+ help
+ Say Y here if you want to use the Group touchscreen filter, it
+ avoids using atypical samples.
+
+config TOUCHSCREEN_FILTER_MEDIAN
+ bool "Median Average Touchscreen Filter"
+ depends on INPUT_TOUCHSCREEN && TOUCHSCREEN_FILTER
+ default Y
+ help
+ Say Y here if you want to use the Median touchscreen filter, it's
+ highly effective if you data is noisy with occasional excursions.
+
+config TOUCHSCREEN_FILTER_MEAN
+ bool "Mean Average Touchscreen Filter"
+ depends on INPUT_TOUCHSCREEN && TOUCHSCREEN_FILTER
+ default Y
+ help
+ Say Y here if you want to use the Mean touchscreen filter, it
+ can further improve decent quality data by removing jitter
+
+config TOUCHSCREEN_FILTER_LINEAR
+ bool "Linear Touchscreen Filter"
+ depends on INPUT_TOUCHSCREEN && TOUCHSCREEN_FILTER
+ default Y
+ help
+ Say Y here if you want to use the Linear touchscreen filter, it
+ enables the use of calibration data for the touchscreen.
+
config TOUCHSCREEN_ADS7846
tristate "ADS7846/TSC2046 and ADS7843 based touchscreens"
depends on SPI_MASTER
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 15fa62cffc7..322df12bb30 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -42,3 +42,8 @@ obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE) += mainstone-wm97xx.o
obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE) += zylonite-wm97xx.o
obj-$(CONFIG_TOUCHSCREEN_W90X900) += w90p910_ts.o
obj-$(CONFIG_TOUCHSCREEN_PCAP) += pcap_ts.o
+obj-$(CONFIG_TOUCHSCREEN_FILTER) += ts_filter_chain.o
+obj-$(CONFIG_TOUCHSCREEN_FILTER_GROUP) += ts_filter_group.o
+obj-$(CONFIG_TOUCHSCREEN_FILTER_LINEAR) += ts_filter_linear.o
+obj-$(CONFIG_TOUCHSCREEN_FILTER_MEDIAN) += ts_filter_median.o
+obj-$(CONFIG_TOUCHSCREEN_FILTER_MEAN) += ts_filter_mean.o
diff --git a/drivers/input/touchscreen/ts_filter.h b/drivers/input/touchscreen/ts_filter.h
new file mode 100644
index 00000000000..632e5fb3f4e
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter.h
@@ -0,0 +1,74 @@
+#ifndef __TS_FILTER_H__
+#define __TS_FILTER_H__
+
+/*
+ * Touchscreen filter.
+ *
+ * (c) 2008,2009 Andy Green <andy@warmcat.com>
+ */
+
+#include <linux/platform_device.h>
+
+#define MAX_TS_FILTER_COORDS 3 /* X, Y and Z (pressure). */
+
+struct ts_filter;
+struct ts_filter_configuration;
+
+/* Operations that a filter can perform. */
+
+struct ts_filter_api {
+ /* Create the filter - mandatory. */
+ struct ts_filter * (*create)(
+ struct platform_device *pdev,
+ const struct ts_filter_configuration *config,
+ int count_coords);
+ /* Destroy the filter - mandatory. */
+ void (*destroy)(struct ts_filter *filter);
+ /* Clear the filter - optional. */
+ void (*clear)(struct ts_filter *filter);
+
+
+ /*
+ * The next three API functions only make sense if all of them are
+ * set for a filter. If a filter has the next three methods then
+ * it can propagate coordinates in the chain.
+ */
+
+ /*
+ * Process the filter.
+ * It returns non-zero if the filter reaches an error.
+ */
+ int (*process)(struct ts_filter *filter, int *coords);
+ /*
+ * Is the filter ready to return a point?
+ * Please do not code side effects in this function.
+ */
+ int (*haspoint)(struct ts_filter *filter);
+ /*
+ * Get a point.
+ * Do not call unless the filter actually has a point to deliver.
+ */
+ void (*getpoint)(struct ts_filter *filter, int *coords);
+
+ /*
+ * Scale the points - optional.
+ * A filter could only scale coordinates.
+ */
+ void (*scale)(struct ts_filter *filter, int *coords);
+};
+
+/*
+ * Generic filter configuration. Actual configurations have this structure
+ * as a member.
+ */
+struct ts_filter_configuration {
+};
+
+struct ts_filter {
+ /* Operations for this filter. */
+ const struct ts_filter_api *api;
+ /* Number of coordinates to process. */
+ int count_coords;
+};
+
+#endif
diff --git a/drivers/input/touchscreen/ts_filter_chain.c b/drivers/input/touchscreen/ts_filter_chain.c
new file mode 100644
index 00000000000..17793ace144
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_chain.c
@@ -0,0 +1,183 @@
+/*
+ * 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) 2008,2009 Andy Green <andy@warmcat.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+
+#include "ts_filter_chain.h"
+#include "ts_filter.h"
+
+/*
+ * Tux, would you like the following function in /lib?
+ * It helps us avoid silly code.
+ */
+
+/**
+ * sptrlen - Count how many non-null pointers are in a pointer array
+ * @arr: The array of pointers
+ */
+static int sptrlen(const void *arr)
+{
+ /* All pointers have the same size. */
+ const int **p = (const int **)arr;
+ int len = 0;
+
+ while (*(p++))
+ len++;
+
+ return len;
+}
+
+
+struct ts_filter_chain {
+ /* All of the filters. */
+ struct ts_filter **arr;
+ /* Filters that can propagate values in the chain. */
+ struct ts_filter **pchain;
+ /* Length of the pchain array. */
+ int pchain_len;
+ /* FIXME: Add a spinlock and use it. */
+};
+
+struct ts_filter_chain *ts_filter_chain_create(
+ struct platform_device *pdev,
+ const struct ts_filter_chain_configuration conf[],
+ int count_coords)
+{
+ struct ts_filter_chain *c;
+ int count = 0;
+ int len;
+
+ BUG_ON((count_coords < 1));
+ BUG_ON(count_coords > MAX_TS_FILTER_COORDS);
+
+ c = kzalloc(sizeof(struct ts_filter_chain), GFP_KERNEL);
+ if (!c)
+ goto create_err_1;
+
+ len = (sptrlen(conf) + 1);
+ /* Memory for two null-terminated arrays of filters. */
+ c->arr = kzalloc(2 * sizeof(struct ts_filter *) * len, GFP_KERNEL);
+ if (!c->arr)
+ goto create_err_1;
+ c->pchain = c->arr + len;
+
+ while (conf->api) {
+ /* TODO: Can we get away with only sending pdev->dev? */
+ struct ts_filter *f =
+ (conf->api->create)(pdev, conf->config, count_coords);
+ if (!f) {
+ dev_info(&pdev->dev, "Filter %d creation failed\n",
+ count);
+ goto create_err_2;
+ }
+
+ f->api = conf->api;
+ c->arr[count++] = f;
+
+ if (f->api->haspoint && f->api->getpoint && f->api->process)
+ c->pchain[c->pchain_len++] = f;
+
+ conf++;
+ }
+
+ dev_info(&pdev->dev, "%d filter(s) initialized\n", count);
+
+ return c;
+
+create_err_2:
+ ts_filter_chain_destroy(c); /* Also frees c. */
+create_err_1:
+ dev_info(&pdev->dev, "Error in filter chain initialization\n");
+ /*
+ * FIXME: Individual filters have to return errors this way.
+ * We only have to forward the errors we find.
+ */
+ return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL_GPL(ts_filter_chain_create);
+
+void ts_filter_chain_destroy(struct ts_filter_chain *c)
+{
+ if (c->arr) {
+ struct ts_filter **a = c->arr;
+ while (*a) {
+ ((*a)->api->destroy)(*a);
+ a++;
+ }
+ kfree(c->arr);
+ }
+ kfree(c);
+}
+EXPORT_SYMBOL_GPL(ts_filter_chain_destroy);
+
+void ts_filter_chain_clear(struct ts_filter_chain *c)
+{
+ struct ts_filter **a = c->arr;
+
+ while (*a) {
+ if ((*a)->api->clear)
+ ((*a)->api->clear)(*a);
+ a++;
+ }
+}
+EXPORT_SYMBOL_GPL(ts_filter_chain_clear);
+
+static void ts_filter_chain_scale(struct ts_filter_chain *c, int *coords)
+{
+ struct ts_filter **a = c->arr;
+ while (*a) {
+ if ((*a)->api->scale)
+ ((*a)->api->scale)(*a, coords);
+ a++;
+ }
+}
+
+int ts_filter_chain_feed(struct ts_filter_chain *c, int *coords)
+{
+ int len = c->pchain_len;
+ int i = len - 1;
+
+ if (!c->pchain[0])
+ return 1; /* Nothing to do. */
+
+ BUG_ON(c->pchain[0]->api->haspoint(c->pchain[0]));
+
+ if (c->pchain[0]->api->process(c->pchain[0], coords))
+ return -1;
+
+ while (i >= 0 && i < len) {
+ if (c->pchain[i]->api->haspoint(c->pchain[i])) {
+ c->pchain[i]->api->getpoint(c->pchain[i], coords);
+ if (++i < len &&
+ c->pchain[i]->api->process(c->pchain[i], coords))
+ return -1; /* Error. */
+ } else {
+ i--;
+ }
+ }
+
+ if (i >= 0) { /* Same as i == len. */
+ ts_filter_chain_scale(c, coords);
+ return 1;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ts_filter_chain_feed);
+
diff --git a/drivers/input/touchscreen/ts_filter_chain.h b/drivers/input/touchscreen/ts_filter_chain.h
new file mode 100644
index 00000000000..065a6a026d2
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_chain.h
@@ -0,0 +1,58 @@
+#ifndef __TS_FILTER_CHAIN_H__
+#define __TS_FILTER_CHAIN_H__
+
+/*
+ * Touchscreen filter chains.
+ *
+ * (c) 2008,2009 Andy Green <andy@warmcat.com>
+ */
+
+#include "ts_filter.h"
+
+#include <linux/err.h>
+
+struct ts_filter_chain_configuration {
+ /* API to use. */
+ const struct ts_filter_api *api;
+ /* Generic filter configuration. Different for each filter. */
+ const struct ts_filter_configuration *config;
+};
+
+struct ts_filter_chain;
+
+#ifdef CONFIG_TOUCHSCREEN_FILTER
+
+/*
+ * Create a filter chain. It will allocate an array of
+ * null-terminated pointers to filters. On error it will return
+ * an error you can check with IS_ERR.
+ */
+extern struct ts_filter_chain *ts_filter_chain_create(
+ struct platform_device *pdev,
+ const struct ts_filter_chain_configuration conf[],
+ int count_coords);
+
+/* Destroy the chain. */
+extern void ts_filter_chain_destroy(struct ts_filter_chain *c);
+
+/* Clear the filter chain. */
+extern void ts_filter_chain_clear(struct ts_filter_chain *c);
+
+/*
+ * Try to get one point. Returns 0 if no points are available.
+ * coords will be used as temporal space, thus you supply a point
+ * using coords but you shouldn't rely on its value on return unless
+ * it returns a nonzero value that is not -1.
+ * If one of the filters find an error then this function will
+ * return -1.
+ */
+int ts_filter_chain_feed(struct ts_filter_chain *c, int *coords);
+
+#else /* !CONFIG_TOUCHSCREEN_FILTER */
+#define ts_filter_chain_create(pdev, config, count_coords) (NULL)
+#define ts_filter_chain_destroy(c) do { } while (0)
+#define ts_filter_chain_clear(c) do { } while (0)
+#define ts_filter_chain_feed(c, coords) (1)
+#endif
+
+#endif
diff --git a/drivers/input/touchscreen/ts_filter_group.c b/drivers/input/touchscreen/ts_filter_group.c
new file mode 100644
index 00000000000..722e8dfbdae
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_group.c
@@ -0,0 +1,330 @@
+/*
+ * 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) 2008,2009 by Openmoko, Inc.
+ * Author: Nelson Castillo <arhuaco@freaks-unidos.net>
+ * All rights reserved.
+ *
+ *
+ * This filter is useful to reject samples that are not reliable. We consider
+ * that a sample is not reliable if it deviates form the Majority.
+ * This filter mixes information from all the available dimensions. It means
+ * that for two dimensions we draw a rectangle where the thought-to-be good
+ * points can be found.
+ *
+ * The implementation would be more efficient with a double-linked list but
+ * let's keep it simple for now.
+ *
+ * 1) We collect S samples and keep it in sorted sets.
+ * - Points that are "close enough" are considered to be in the same set.
+ * We don't actually keep the sets but ranges of points.
+ *
+ * 2) For each dimension:
+ * - We choose the range with more elements. If more than "threshold"
+ * points are in this range we use the minimum and the maximum point
+ * of the range to define the valid range for this dimension [min, max],
+ * otherwise we discard all the points and the ranges and go to step 1.
+ *
+ * 3) We consider the unsorted S samples and try to feed them to the next
+ * filter in the chain. If one of the points of each sample
+ * is not in the allowed range for its dimension we discard the sample.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include "ts_filter_group.h"
+
+struct coord_range {
+ int min; /* Minimum value of the range. */
+ int max; /* Maximum value of the range */
+ int N; /* Number of points in the range. */
+};
+
+struct ts_filter_group {
+ /* Private filter configuration. */
+ struct ts_filter_group_configuration *config;
+ /* Filter API. */
+ struct ts_filter tsf;
+
+ int N; /* How many samples we have. */
+ int *samples[MAX_TS_FILTER_COORDS]; /* The samples: our input. */
+
+ /* Temporal values that help us compute range_min and range_max. */
+ struct coord_range *ranges[MAX_TS_FILTER_COORDS]; /* Ranges. */
+ int n_ranges[MAX_TS_FILTER_COORDS]; /* Number of ranges */
+
+ /* Computed ranges that help us filter the points. */
+ int range_max[MAX_TS_FILTER_COORDS]; /* Max. computed ranges. */
+ int range_min[MAX_TS_FILTER_COORDS]; /* Min. computed ranges. */
+
+ int tries_left; /* We finish if we can't get enough samples. */
+ int ready; /* If we are ready to deliver samples. */
+ int result; /* Index of the point being returned. */
+};
+
+#define ts_filter_to_filter_group(f) \
+ container_of(f, struct ts_filter_group, tsf)
+
+
+static void ts_filter_group_clear_internal(struct ts_filter_group *tsfg,
+ int attempts)
+{
+ int n;
+ tsfg->N = 0;
+ tsfg->tries_left = attempts;
+ tsfg->ready = 0;
+ tsfg->result = 0;
+ for (n = 0; n < tsfg->tsf.count_coords; n++)
+ tsfg->n_ranges[n] = 0;
+}
+
+static void ts_filter_group_clear(struct ts_filter *tsf)
+{
+ struct ts_filter_group *tsfg = ts_filter_to_filter_group(tsf);
+
+ ts_filter_group_clear_internal(tsfg, tsfg->config->attempts);
+}
+
+static struct ts_filter *ts_filter_group_create(
+ struct platform_device *pdev,
+ const struct ts_filter_configuration *conf,
+ int count_coords)
+{
+ struct ts_filter_group *tsfg;
+ int i;
+
+ tsfg = kzalloc(sizeof(struct ts_filter_group), GFP_KERNEL);
+ if (!tsfg)
+ return NULL;
+
+ tsfg->config = container_of(conf,
+ struct ts_filter_group_configuration,
+ config);
+ tsfg->tsf.count_coords = count_coords;
+
+ BUG_ON(tsfg->config->attempts <= 0);
+ BUG_ON(tsfg->config->length < tsfg->config->threshold);
+
+ tsfg->samples[0] = kmalloc(count_coords * sizeof(int) *
+ tsfg->config->length, GFP_KERNEL);
+ if (!tsfg->samples[0]) {
+ kfree(tsfg);
+ return NULL;
+ }
+ for (i = 1; i < count_coords; ++i)
+ tsfg->samples[i] = tsfg->samples[0] + i * tsfg->config->length;
+
+ tsfg->ranges[0] = kmalloc(count_coords * sizeof(struct coord_range) *
+ tsfg->config->length, GFP_KERNEL);
+ if (!tsfg->ranges[0]) {
+ kfree(tsfg->samples[0]);
+ kfree(tsfg);
+ return NULL;
+ }
+ for (i = 1; i < count_coords; ++i)
+ tsfg->ranges[i] = tsfg->ranges[0] + i * tsfg->config->length;
+
+ ts_filter_group_clear_internal(tsfg, tsfg->config->attempts);
+
+ dev_info(&pdev->dev, "Created Group filter len:%d coords:%d close:%d "
+ "thresh:%d\n", tsfg->config->length, count_coords,
+ tsfg->config->close_enough, tsfg->config->threshold);
+
+ return &tsfg->tsf;
+}
+
+static void ts_filter_group_destroy(struct ts_filter *tsf)
+{
+ struct ts_filter_group *tsfg = ts_filter_to_filter_group(tsf);
+
+ kfree(tsfg->samples[0]);
+ kfree(tsfg->ranges[0]);
+ kfree(tsf);
+}
+
+static void ts_filter_group_prepare_next(struct ts_filter *tsf);
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#define IN_RANGE(c, r) ((c) >= (r).min - tsfg->config->close_enough && \
+ (c) <= (r).max + tsfg->config->close_enough)
+
+static void delete_spot(struct coord_range *v, int n, int size)
+{
+ int i;
+ for (i = n; i < size - 1; ++i)
+ v[i] = v[i + 1];
+}
+
+static int ts_filter_group_process(struct ts_filter *tsf, int *coords)
+{
+ struct ts_filter_group *tsfg = ts_filter_to_filter_group(tsf);
+ int n;
+ int j;
+
+ BUG_ON(tsfg->N >= tsfg->config->length);
+ BUG_ON(tsfg->ready);
+
+ for (n = 0; n < tsfg->tsf.count_coords; n++) {
+ int i;
+ struct coord_range *range = tsfg->ranges[n];
+ int *n_ranges = &tsfg->n_ranges[n];
+ int found = 0;
+
+ tsfg->samples[n][tsfg->N] = coords[n];
+
+ for (i = 0; i < *n_ranges; ++i) {
+ if (IN_RANGE(coords[n], range[i])) {
+ range[i].min = MIN(range[i].min, coords[n]);
+ range[i].max = MAX(range[i].max, coords[n]);
+ range[i].N++;
+ found = 1;
+ break;
+ } else if (coords[n] <= range[i].min)
+ break; /* We need to insert a range. */
+ }
+ if (found) { /* We might need to melt ranges. */
+ if (i && range[i - 1].max + tsfg->config->close_enough
+ >= range[i].min) {
+ BUG_ON(range[i - 1].max >= range[i].max);
+ range[i - 1].max = range[i].max;
+ range[i - 1].N += range[i].N;
+ delete_spot(range, i, *n_ranges);
+ (*n_ranges)--;
+ i--;
+ }
+ if (i < *n_ranges - 1 && range[i + 1].min -
+ tsfg->config->close_enough <= range[i].max) {
+ range[i].max = range[i + 1].max;
+ range[i].N += range[i + 1].N;
+ delete_spot(range, i + 1, *n_ranges);
+ (*n_ranges)--;
+ }
+ } else {
+ BUG_ON((*n_ranges) >= tsfg->config->length);
+ (*n_ranges)++;
+ for (j = *n_ranges - 1; j > i; --j)
+ range[j] = range[j - 1];
+ range[i].N = 1;
+ range[i].min = coords[n];
+ range[i].max = coords[n];
+ }
+ }
+
+ if (++tsfg->N < tsfg->config->length)
+ return 0;
+
+ for (n = 0; n < tsfg->tsf.count_coords; ++n) {
+ int best = 0;
+ for (j = 1; j < tsfg->n_ranges[n]; ++j)
+ if (tsfg->ranges[n][best].N < tsfg->ranges[n][j].N)
+ best = j;
+ if (tsfg->ranges[n][best].N < tsfg->config->threshold) {
+ /* This set of points is not good enough for us. */
+ if (--tsfg->tries_left) {
+ ts_filter_group_clear_internal
+ (tsfg, tsfg->tries_left);
+ /* No errors but we need more samples. */
+ return 0;
+ }
+ return 1; /* We give up: error. */
+ }
+ tsfg->range_min[n] = tsfg->ranges[n][best].min;
+ tsfg->range_max[n] = tsfg->ranges[n][best].max;
+ }
+
+ ts_filter_group_prepare_next(tsf);
+
+ return 0;
+}
+
+/*
+ * This private function prepares a point that will be returned
+ * in ts_filter_group_getpoint if it is available. It updates
+ * the priv->ready state also.
+ */
+static void ts_filter_group_prepare_next(struct ts_filter *tsf)
+{
+ struct ts_filter_group *priv = ts_filter_to_filter_group(tsf);
+ int n;
+
+ while (priv->result < priv->N) {
+ for (n = 0; n < priv->tsf.count_coords; ++n) {
+ if (priv->samples[n][priv->result] <
+ priv->range_min[n] ||
+ priv->samples[n][priv->result] > priv->range_max[n])
+ break;
+ }
+
+ if (n == priv->tsf.count_coords) /* Sample is OK. */
+ break;
+
+ priv->result++;
+ }
+
+ if (unlikely(priv->result >= priv->N)) { /* No sample to deliver. */
+ ts_filter_group_clear_internal(priv, priv->config->attempts);
+ priv->ready = 0;
+ } else {
+ priv->ready = 1;
+ }
+}
+
+static int ts_filter_group_haspoint(struct ts_filter *tsf)
+{
+ struct ts_filter_group *priv = ts_filter_to_filter_group(tsf);
+
+ return priv->ready;
+}
+
+static void ts_filter_group_getpoint(struct ts_filter *tsf, int *point)
+{
+ struct ts_filter_group *priv = ts_filter_to_filter_group(tsf);
+ int n;
+
+ BUG_ON(!priv->ready);
+
+ for (n = 0; n < priv->tsf.count_coords; n++)
+ point[n] = priv->samples[n][priv->result];
+
+ priv->result++;
+
+ /* This call will update priv->ready. */
+ ts_filter_group_prepare_next(tsf);
+}
+
+/*
+ * Get ready to process the next batch of points, forget
+ * points we could have delivered.
+ */
+static void ts_filter_group_scale(struct ts_filter *tsf, int *coords)
+{
+ struct ts_filter_group *priv = ts_filter_to_filter_group(tsf);
+
+ ts_filter_group_clear_internal(priv, priv->config->attempts);
+}
+
+const struct ts_filter_api ts_filter_group_api = {
+ .create = ts_filter_group_create,
+ .destroy = ts_filter_group_destroy,
+ .clear = ts_filter_group_clear,
+ .process = ts_filter_group_process,
+ .haspoint = ts_filter_group_haspoint,
+ .getpoint = ts_filter_group_getpoint,
+ .scale = ts_filter_group_scale,
+};
+EXPORT_SYMBOL_GPL(ts_filter_group_api);
+
diff --git a/drivers/input/touchscreen/ts_filter_group.h b/drivers/input/touchscreen/ts_filter_group.h
new file mode 100644
index 00000000000..d1e3590e936
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_group.h
@@ -0,0 +1,36 @@
+#ifndef __TS_FILTER_GROUP_H__
+#define __TS_FILTER_GROUP_H__
+
+#include "ts_filter.h"
+
+/*
+ * Touchscreen group filter.
+ *
+ * Copyright (C) 2008,2009 by Openmoko, Inc.
+ * Author: Nelson Castillo <arhuaco@freaks-unidos.net>
+ *
+ */
+
+struct ts_filter_group_configuration {
+ /* Size of the filter. */
+ int length;
+ /*
+ * If two points are separated by this distance or less they
+ * are considered to be members of the same group.
+ */
+ int close_enough;
+ /* Minimum allowed size for the biggest group in the sample set. */
+ int threshold;
+ /*
+ * Number of times we try to get a group of points with at least
+ * threshold points.
+ */
+ int attempts;
+
+ /* Generic filter configuration. */
+ struct ts_filter_configuration config;
+};
+
+extern const struct ts_filter_api ts_filter_group_api;
+
+#endif
diff --git a/drivers/input/touchscreen/ts_filter_linear.c b/drivers/input/touchscreen/ts_filter_linear.c
new file mode 100644
index 00000000000..7718bbc6e6d
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_linear.c
@@ -0,0 +1,212 @@
+/*
+ * 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; 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) 2008,2009 by Openmoko, Inc.
+ * Author: Nelson Castillo <arhuaco@freaks-unidos.net>
+ * All rights reserved.
+ *
+ * Linearly scale touchscreen values.
+ *
+ * Expose the TS_FILTER_LINEAR_NCONSTANTS for the linear transformation
+ * using sysfs.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "ts_filter_linear.h"
+
+struct ts_filter_linear;
+
+/* Sysfs code. */
+
+struct const_obj {
+ /* The actual private object. */
+ struct ts_filter_linear *tsfl;
+ /* Our kobject. */
+ struct kobject kobj;
+};
+
+#define to_const_obj(x) container_of(x, struct const_obj, kobj)
+
+struct const_attribute {
+ struct attribute attr;
+ ssize_t (*show)(struct const_obj *const, struct const_attribute *attr,
+ char *buf);
+ ssize_t (*store)(struct const_obj *const, struct const_attribute *attr,
+ const char *buf, size_t count);
+};
+
+#define to_const_attr(x) container_of(x, struct const_attribute, attr)
+
+
+/* Private linear filter structure. */
+
+struct ts_filter_linear {
+ /* Private configuration for this filter. */
+ struct ts_filter_linear_configuration *config;
+
+ /* Generic filter API. */
+ struct ts_filter tsf;
+
+ /* Linear constants for the transformation. */
+ int constants[TS_FILTER_LINEAR_NCONSTANTS];
+
+ /* Sysfs. */
+
+ /* Our const_object. */
+ struct const_obj c_obj;
+ /* Our type. We will stick operations to it. */
+ struct kobj_type const_ktype;
+ /* Attrs. of the virtual files. */
+ struct const_attribute kattrs[TS_FILTER_LINEAR_NCONSTANTS];
+ /* Default Attrs. Always NULL for us. */
+ struct attribute *attrs[TS_FILTER_LINEAR_NCONSTANTS + 1];
+ /* Storage for the name of the virtual files. */
+ char attr_names[TS_FILTER_LINEAR_NCONSTANTS][2];
+};
+
+#define ts_filter_to_filter_linear(f) \
+ container_of(f, struct ts_filter_linear, tsf)
+
+/* Sysfs functions. */
+
+static ssize_t const_attr_show(struct kobject *kobj,
+ struct attribute *attr,
+ char *buf)
+{
+ struct const_attribute *a = to_const_attr(attr);
+
+ return a->show(to_const_obj(kobj), a, buf);
+}
+
+static ssize_t const_attr_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buf, size_t len)
+{
+ struct const_attribute *a = to_const_attr(attr);
+
+ return a->store(to_const_obj(kobj), a, buf, len);
+}
+
+static struct sysfs_ops const_sysfs_ops = {
+ .show = const_attr_show,
+ .store = const_attr_store,
+};
+
+static void const_release(struct kobject *kobj)
+{
+ kfree(to_const_obj(kobj)->tsfl);
+}
+
+static ssize_t const_show(struct const_obj *obj, struct const_attribute *attr,
+ char *buf)
+{
+ int who;
+
+ sscanf(attr->attr.name, "%d", &who);
+ return sprintf(buf, "%d\n", obj->tsfl->constants[who]);
+}
+
+static ssize_t const_store(struct const_obj *obj, struct const_attribute *attr,
+ const char *buf, size_t count)
+{
+ int who;
+
+ sscanf(attr->attr.name, "%d", &who);
+ sscanf(buf, "%d", &obj->tsfl->constants[who]);
+ return count;
+}
+
+/* Filter functions. */
+
+static struct ts_filter *ts_filter_linear_create(
+ struct platform_device *pdev,
+ const struct ts_filter_configuration *conf,
+ int count_coords)
+{
+ struct ts_filter_linear *tsfl;
+ int i;
+ int ret;
+
+ tsfl = kzalloc(sizeof(struct ts_filter_linear), GFP_KERNEL);
+ if (!tsfl)
+ return NULL;
+
+ tsfl->config = container_of(conf,
+ struct ts_filter_linear_configuration,
+ config);
+
+ tsfl->tsf.count_coords = count_coords;
+
+ for (i = 0; i < TS_FILTER_LINEAR_NCONSTANTS; ++i) {
+ tsfl->constants[i] = tsfl->config->constants[i];
+
+ /* sysfs */
+ sprintf(tsfl->attr_names[i], "%d", i);
+ tsfl->kattrs[i].attr.name = tsfl->attr_names[i];
+ tsfl->kattrs[i].attr.mode = 0666;
+ tsfl->kattrs[i].show = const_show;
+ tsfl->kattrs[i].store = const_store;
+ tsfl->attrs[i] = &tsfl->kattrs[i].attr;
+ }
+ tsfl->attrs[i] = NULL;
+
+ tsfl->const_ktype.sysfs_ops = &const_sysfs_ops;
+ tsfl->const_ktype.release = const_release;
+ tsfl->const_ktype.default_attrs = tsfl->attrs;
+ tsfl->c_obj.tsfl = tsfl; /* kernel frees tsfl in const_release */
+
+ ret = kobject_init_and_add(&tsfl->c_obj.kobj, &tsfl->const_ktype,
+ &pdev->dev.kobj, "calibration");
+ if (ret) {
+ kobject_put(&tsfl->c_obj.kobj);
+ return NULL;
+ }
+
+ dev_info(&pdev->dev, "Created Linear filter coords:%d\n", count_coords);
+
+ return &tsfl->tsf;
+}
+
+static void ts_filter_linear_destroy(struct ts_filter *tsf)
+{
+ struct ts_filter_linear *tsfl = ts_filter_to_filter_linear(tsf);
+
+ /* Kernel frees tsfl in const_release. */
+ kobject_put(&tsfl->c_obj.kobj);
+}
+
+static void ts_filter_linear_scale(struct ts_filter *tsf, int *coords)
+{
+ struct ts_filter_linear *tsfl = ts_filter_to_filter_linear(tsf);
+
+ int *k = tsfl->constants;
+ int c0 = coords[tsfl->config->coord0];
+ int c1 = coords[tsfl->config->coord1];
+
+ coords[tsfl->config->coord0] = (k[2] + k[0] * c0 + k[1] * c1) / k[6];
+ coords[tsfl->config->coord1] = (k[5] + k[3] * c0 + k[4] * c1) / k[6];
+}
+
+const struct ts_filter_api ts_filter_linear_api = {
+ .create = ts_filter_linear_create,
+ .destroy = ts_filter_linear_destroy,
+ .scale = ts_filter_linear_scale,
+};
+EXPORT_SYMBOL_GPL(ts_filter_linear_api);
+
diff --git a/drivers/input/touchscreen/ts_filter_linear.h b/drivers/input/touchscreen/ts_filter_linear.h
new file mode 100644
index 00000000000..82df3d25b50
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_linear.h
@@ -0,0 +1,31 @@
+#ifndef __TS_FILTER_LINEAR_H__
+#define __TS_FILTER_LINEAR_H__
+
+#include "ts_filter.h"
+#include <linux/kobject.h>
+
+/*
+ * Touchscreen linear filter.
+ *
+ * Copyright (C) 2008,2009 by Openmoko, Inc.
+ * Author: Nelson Castillo <arhuaco@freaks-unidos.net>
+ *
+ */
+
+#define TS_FILTER_LINEAR_NCONSTANTS 7
+
+struct ts_filter_linear_configuration {
+ /* Calibration constants. */
+ int constants[TS_FILTER_LINEAR_NCONSTANTS];
+ /* First coordinate. */
+ int coord0;
+ /* Second coordinate. */
+ int coord1;
+
+ /* Generic filter configuration. */
+ struct ts_filter_configuration config;
+};
+
+extern const struct ts_filter_api ts_filter_linear_api;
+
+#endif
diff --git a/drivers/input/touchscreen/ts_filter_mean.c b/drivers/input/touchscreen/ts_filter_mean.c
new file mode 100644
index 00000000000..0c604321713
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_mean.c
@@ -0,0 +1,174 @@
+/*
+ * 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) 2008,2009
+ * Andy Green <andy@warmcat.com>
+ * Nelson Castillo <arhuaco@freaks-unidos.net>
+ *
+ * Simple mean filter.
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include "ts_filter_mean.h"
+
+struct ts_filter_mean {
+ /* Copy of the private filter configuration. */
+ struct ts_filter_mean_configuration *config;
+ /* Filter API. */
+ struct ts_filter tsf;
+
+ /* Index on a circular buffer. */
+ int curr;
+ /* Useful to tell if the circular buffer is full(read:ready). */
+ int count;
+ /* Sumation used to compute the mean. */
+ int sum[MAX_TS_FILTER_COORDS];
+ /* Keep point values and decrement them from the sum on time. */
+ int *fifo[MAX_TS_FILTER_COORDS];
+ /* Store the output of this filter. */
+ int ready;
+};
+
+#define ts_filter_to_filter_mean(f) container_of(f, struct ts_filter_mean, tsf)
+
+
+static void ts_filter_mean_clear(struct ts_filter *tsf);
+
+static struct ts_filter *ts_filter_mean_create(
+ struct platform_device *pdev,
+ const struct ts_filter_configuration *conf,
+ int count_coords)
+{
+ struct ts_filter_mean *priv;
+ int *v;
+ int n;
+
+ priv = kzalloc(sizeof(struct ts_filter_mean), GFP_KERNEL);
+ if (!priv)
+ return NULL;
+
+ priv->tsf.count_coords = count_coords;
+ priv->config = container_of(conf,
+ struct ts_filter_mean_configuration,
+ config);
+
+ BUG_ON(priv->config->length <= 0);
+
+ v = kmalloc(priv->config->length * sizeof(int) * count_coords,
+ GFP_KERNEL);
+ if (!v)
+ return NULL;
+
+ for (n = 0; n < count_coords; n++) {
+ priv->fifo[n] = v;
+ v += priv->config->length;
+ }
+
+ ts_filter_mean_clear(&priv->tsf);
+
+ dev_info(&pdev->dev, "Created Mean filter len:%d coords:%d\n",
+ priv->config->length, count_coords);
+
+ return &priv->tsf;
+}
+
+static void ts_filter_mean_destroy(struct ts_filter *tsf)
+{
+ struct ts_filter_mean *priv = ts_filter_to_filter_mean(tsf);
+
+ kfree(priv->fifo[0]); /* first guy has pointer from kmalloc */
+ kfree(tsf);
+}
+
+static void ts_filter_mean_clear(struct ts_filter *tsf)
+{
+ struct ts_filter_mean *priv = ts_filter_to_filter_mean(tsf);
+
+ priv->count = 0;
+ priv->curr = 0;
+ priv->ready = 0;
+ memset(priv->sum, 0, tsf->count_coords * sizeof(int));
+}
+
+static int ts_filter_mean_process(struct ts_filter *tsf, int *coords)
+{
+ struct ts_filter_mean *priv = ts_filter_to_filter_mean(tsf);
+ int n;
+
+ BUG_ON(priv->ready);
+
+ for (n = 0; n < tsf->count_coords; n++) {
+ priv->sum[n] += coords[n];
+ priv->fifo[n][priv->curr] = coords[n];
+ }
+
+ if (priv->count + 1 == priv->config->length)
+ priv->ready = 1;
+ else
+ priv->count++;
+
+ priv->curr = (priv->curr + 1) % priv->config->length;
+
+ return 0; /* No error. */
+}
+
+static int ts_filter_mean_haspoint(struct ts_filter *tsf)
+{
+ struct ts_filter_mean *priv = ts_filter_to_filter_mean(tsf);
+
+ return priv->ready;
+}
+
+static void ts_filter_mean_getpoint(struct ts_filter *tsf, int *point)
+{
+ struct ts_filter_mean *priv = ts_filter_to_filter_mean(tsf);
+ int n;
+
+ BUG_ON(!priv->ready);
+
+ for (n = 0; n < tsf->count_coords; n++) {
+ point[n] = priv->sum[n];
+ priv->sum[n] -= priv->fifo[n][priv->curr];
+ }
+
+ priv->ready = 0;
+}
+
+static void ts_filter_mean_scale(struct ts_filter *tsf, int *coords)
+{
+ int n;
+ struct ts_filter_mean *priv = ts_filter_to_filter_mean(tsf);
+
+ for (n = 0; n < tsf->count_coords; n++) {
+ coords[n] += priv->config->length >> 1; /* Rounding. */
+ coords[n] /= priv->config->length;
+ }
+}
+
+const struct ts_filter_api ts_filter_mean_api = {
+ .create = ts_filter_mean_create,
+ .destroy = ts_filter_mean_destroy,
+ .clear = ts_filter_mean_clear,
+ .process = ts_filter_mean_process,
+ .scale = ts_filter_mean_scale,
+ .haspoint = ts_filter_mean_haspoint,
+ .getpoint = ts_filter_mean_getpoint,
+};
+EXPORT_SYMBOL_GPL(ts_filter_mean_api);
+
diff --git a/drivers/input/touchscreen/ts_filter_mean.h b/drivers/input/touchscreen/ts_filter_mean.h
new file mode 100644
index 00000000000..80f9b215dff
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_mean.h
@@ -0,0 +1,28 @@
+#ifndef __TS_FILTER_MEAN_H__
+#define __TS_FILTER_MEAN_H__
+
+#include "ts_filter.h"
+
+/*
+ * Touchscreen filter.
+ *
+ * mean
+ *
+ * (c) 2008,2009
+ * Andy Green <andy@warmcat.com>
+ * Nelson Castillo <arhuaco@freaks-unidos.net>
+ */
+
+/* Configuration for this filter. */
+struct ts_filter_mean_configuration {
+ /* Number of points for the mean. */
+ int length;
+
+ /* Generic filter configuration. */
+ struct ts_filter_configuration config;
+};
+
+/* API functions for the mean filter */
+extern const struct ts_filter_api ts_filter_mean_api;
+
+#endif /* __TS_FILTER_MEAN_H__ */
diff --git a/drivers/input/touchscreen/ts_filter_median.c b/drivers/input/touchscreen/ts_filter_median.c
new file mode 100644
index 00000000000..6f8aae5941d
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_median.c
@@ -0,0 +1,261 @@
+/*
+ * 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@warmcat.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 "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);
+
diff --git a/drivers/input/touchscreen/ts_filter_median.h b/drivers/input/touchscreen/ts_filter_median.h
new file mode 100644
index 00000000000..b13f361bb6a
--- /dev/null
+++ b/drivers/input/touchscreen/ts_filter_median.h
@@ -0,0 +1,32 @@
+#ifndef __TS_FILTER_MEDIAN_H__
+#define __TS_FILTER_MEDIAN_H__
+
+#include "ts_filter.h"
+
+/*
+ * Touchscreen filter.
+ *
+ * median
+ *
+ * (c) 2008 Andy Green <andy@warmcat.com>
+ */
+
+struct ts_filter_median_configuration {
+ /* Size of the filter. */
+ int extent;
+ /* Precomputed midpoint. */
+ int midpoint;
+ /* A reference value for us to check if we are going fast or slow. */
+ int decimation_threshold;
+ /* How many points to replace if we're going fast. */
+ int decimation_above;
+ /* How many points to replace if we're going slow. */
+ int decimation_below;
+
+ /* Generic configuration. */
+ struct ts_filter_configuration config;
+};
+
+extern const struct ts_filter_api ts_filter_median_api;
+
+#endif