2 * accelerometer - exports device orientation through property
4 * When an "change" event is received on an accelerometer,
5 * open its device node, and from the value, as well as the previous
6 * value of the property, calculate the device's new orientation,
7 * and export it as ID_INPUT_ACCELEROMETER_ORIENTATION.
16 * The property will be persistent across sessions, and the new
17 * orientations can be deducted from the previous one (it allows
18 * for a threshold for switching between opposite ends of the
21 * Copyright (C) 2011 Red Hat, Inc.
23 * Bastien Nocera <hadess@hadess.net>
25 * orientation_calc() from the sensorfw package
26 * Copyright (C) 2009-2010 Nokia Corporation
28 * Üstün Ergenoglu <ext-ustun.ergenoglu@nokia.com>
29 * Timo Rongas <ext-timo.2.rongas@nokia.com>
30 * Lihan Guo <lihan.guo@digia.com>
32 * This program is free software; you can redistribute it and/or modify
33 * it under the terms of the GNU General Public License as published by
34 * the Free Software Foundation; either version 2 of the License, or
35 * (at your option) any later version.
37 * This program is distributed in the hope that it will be useful,
38 * but WITHOUT ANY WARRANTY; without even the implied warranty of
39 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
40 * GNU General Public License for more details.
42 * You should have received a copy of the GNU General Public License along
43 * with this program; if not, write to the Free Software Foundation, Inc.,
44 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
53 #include <linux/input.h>
56 #include "libudev-private.h"
58 /* we must use this kernel-compatible implementation */
59 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
60 #define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
61 #define OFF(x) ((x)%BITS_PER_LONG)
62 #define BIT(x) (1UL<<OFF(x))
63 #define LONG(x) ((x)/BITS_PER_LONG)
64 #define test_bit(bit, array) ((array[LONG(bit)] >> OFF(bit)) & 1)
67 ORIENTATION_UNDEFINED,
69 ORIENTATION_BOTTOM_UP,
74 static const char *orientations[] = {
83 #define ORIENTATION_UP_UP ORIENTATION_NORMAL
85 #define DEFAULT_THRESHOLD 250
86 #define RADIANS_TO_DEGREES 180.0/M_PI
87 #define SAME_AXIS_LIMIT 5
89 #define THRESHOLD_LANDSCAPE 25
90 #define THRESHOLD_PORTRAIT 20
93 orientation_to_string (OrientationUp o)
95 return orientations[o];
99 string_to_orientation (const char *orientation)
103 if (orientation == NULL)
104 return ORIENTATION_UNDEFINED;
105 for (i = 0; orientations[i] != NULL; i++) {
106 if (streq (orientation, orientations[i]))
109 return ORIENTATION_UNDEFINED;
113 orientation_calc (OrientationUp prev,
117 OrientationUp ret = prev;
120 rotation = round(atan((double) x / sqrt(y * y + z * z)) * RADIANS_TO_DEGREES);
122 if (abs(rotation) > THRESHOLD_PORTRAIT) {
123 ret = (rotation < 0) ? ORIENTATION_LEFT_UP : ORIENTATION_RIGHT_UP;
125 /* Some threshold to switching between portrait modes */
126 if (prev == ORIENTATION_LEFT_UP || prev == ORIENTATION_RIGHT_UP) {
127 if (abs(rotation) < SAME_AXIS_LIMIT) {
133 /* Landscape check */
134 rotation = round(atan((double) y / sqrt(x * x + z * z)) * RADIANS_TO_DEGREES);
136 if (abs(rotation) > THRESHOLD_LANDSCAPE) {
137 ret = (rotation < 0) ? ORIENTATION_BOTTOM_UP : ORIENTATION_NORMAL;
139 /* Some threshold to switching between landscape modes */
140 if (prev == ORIENTATION_BOTTOM_UP || prev == ORIENTATION_NORMAL) {
141 if (abs(rotation) < SAME_AXIS_LIMIT) {
152 get_prev_orientation(struct udev_device *dev)
156 value = udev_device_get_property_value(dev, "ID_INPUT_ACCELEROMETER_ORIENTATION");
158 return ORIENTATION_UNDEFINED;
159 return string_to_orientation(value);
162 #define READ_AXIS(axis, var) { memzero(&abs_info, sizeof(abs_info)); r = ioctl(fd, EVIOCGABS(axis), &abs_info); if (r < 0) return; var = abs_info.value; }
165 static void test_orientation(struct udev *udev,
166 struct udev_device *dev,
169 OrientationUp old, new;
170 _cleanup_close_ int fd = -1;
171 struct input_absinfo abs_info;
172 int x = 0, y = 0, z = 0;
176 old = get_prev_orientation(dev);
178 fd = open(devpath, O_RDONLY|O_CLOEXEC);
186 new = orientation_calc(old, x, y, z);
187 snprintf(text, sizeof(text),
188 "ID_INPUT_ACCELEROMETER_ORIENTATION=%s", orientation_to_string(new));
192 static void help(void) {
194 printf("%s [options] <device path>\n\n"
195 "Accelerometer device identification.\n\n"
196 " -h --help Print this message\n"
197 " -d --debug Debug to stderr\n"
198 , program_invocation_short_name);
201 int main (int argc, char** argv)
204 struct udev_device *dev;
206 static const struct option options[] = {
207 { "debug", no_argument, NULL, 'd' },
208 { "help", no_argument, NULL, 'h' },
212 char devpath[PATH_MAX];
214 struct udev_enumerate *enumerate;
215 struct udev_list_entry *list_entry;
217 log_parse_environment();
224 /* CLI argument parsing */
228 option = getopt_long(argc, argv, "dh", options, NULL);
234 log_set_target(LOG_TARGET_CONSOLE);
235 log_set_max_level(LOG_DEBUG);
246 if (argv[optind] == NULL) {
252 snprintf(devpath, sizeof(devpath), "/sys/%s", argv[optind]);
253 dev = udev_device_new_from_syspath(udev, devpath);
255 fprintf(stderr, "unable to access '%s'\n", devpath);
259 /* Get the children devices and find the devnode */
261 enumerate = udev_enumerate_new(udev);
262 udev_enumerate_add_match_parent(enumerate, dev);
263 udev_enumerate_scan_devices(enumerate);
264 udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(enumerate)) {
265 struct udev_device *device;
268 device = udev_device_new_from_syspath(udev_enumerate_get_udev(enumerate),
269 udev_list_entry_get_name(list_entry));
272 /* Already found it */
273 if (devnode != NULL) {
274 udev_device_unref(device);
278 node = udev_device_get_devnode(device);
280 udev_device_unref(device);
283 /* Use the event sub-device */
284 if (strstr(node, "/event") == NULL) {
285 udev_device_unref(device);
289 devnode = strdup(node);
290 udev_device_unref(device);
293 if (devnode == NULL) {
294 fprintf(stderr, "unable to get device node for '%s'\n", devpath);
298 log_debug("opening accelerometer device %s", devnode);
299 test_orientation(udev, dev, devnode);