diff options
Diffstat (limited to 'drivers/input/touchscreen/ts_filter_linear.c')
| -rw-r--r-- | drivers/input/touchscreen/ts_filter_linear.c | 212 |
1 files changed, 212 insertions, 0 deletions
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); + |