2 * expose input properties via udev
4 * Copyright (C) 2009 Martin Pitt <martin.pitt@ubuntu.com>
5 * Portions Copyright (C) 2004 David Zeuthen, <david@fubar.dk>
6 * Copyright (C) 2011 Kay Sievers <kay@vrfy.org>
7 * Copyright (C) 2014 Carlos Garnacho <carlosg@gnome.org>
8 * Copyright (C) 2014 David Herrmann <dh.herrmann@gmail.com>
10 * This program is free software: you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation, either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program. If not, see <http://www.gnu.org/licenses/>.
30 #include <linux/limits.h>
31 #include <linux/input.h>
36 /* we must use this kernel-compatible implementation */
37 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
38 #define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
39 #define OFF(x) ((x)%BITS_PER_LONG)
40 #define BIT(x) (1UL<<OFF(x))
41 #define LONG(x) ((x)/BITS_PER_LONG)
42 #define test_bit(bit, array) ((array[LONG(bit)] >> OFF(bit)) & 1)
44 static inline int abs_size_mm(const struct input_absinfo *absinfo) {
45 /* Resolution is defined to be in units/mm for ABS_X/Y */
46 return (absinfo->maximum - absinfo->minimum) / absinfo->resolution;
49 static void extract_info(struct udev_device *dev, const char *devpath, bool test) {
50 char width[DECIMAL_STR_MAX(int)], height[DECIMAL_STR_MAX(int)];
51 struct input_absinfo xabsinfo = {}, yabsinfo = {};
52 _cleanup_close_ int fd = -1;
54 fd = open(devpath, O_RDONLY|O_CLOEXEC);
58 if (ioctl(fd, EVIOCGABS(ABS_X), &xabsinfo) < 0 ||
59 ioctl(fd, EVIOCGABS(ABS_Y), &yabsinfo) < 0)
62 if (xabsinfo.resolution <= 0 || yabsinfo.resolution <= 0)
65 snprintf(width, sizeof(width), "%d", abs_size_mm(&xabsinfo));
66 snprintf(height, sizeof(height), "%d", abs_size_mm(&yabsinfo));
68 udev_builtin_add_property(dev, test, "ID_INPUT_WIDTH_MM", width);
69 udev_builtin_add_property(dev, test, "ID_INPUT_HEIGHT_MM", height);
73 * Read a capability attribute and return bitmask.
74 * @param dev udev_device
75 * @param attr sysfs attribute name (e. g. "capabilities/key")
76 * @param bitmask: Output array which has a sizeof of bitmask_size
78 static void get_cap_mask(struct udev_device *dev,
79 struct udev_device *pdev, const char* attr,
80 unsigned long *bitmask, size_t bitmask_size,
88 v = udev_device_get_sysattr_value(pdev, attr);
92 snprintf(text, sizeof(text), "%s", v);
93 log_debug("%s raw kernel attribute: %s", attr, text);
95 memzero(bitmask, bitmask_size);
97 while ((word = strrchr(text, ' ')) != NULL) {
98 val = strtoul (word+1, NULL, 16);
99 if (i < bitmask_size/sizeof(unsigned long))
102 log_debug("ignoring %s block %lX which is larger than maximum size", attr, val);
106 val = strtoul (text, NULL, 16);
107 if (i < bitmask_size / sizeof(unsigned long))
110 log_debug("ignoring %s block %lX which is larger than maximum size", attr, val);
113 /* printf pattern with the right unsigned long number of hex chars */
114 snprintf(text, sizeof(text), " bit %%4u: %%0%zulX\n", 2 * sizeof(unsigned long));
115 log_debug("%s decoded bit map:", attr);
116 val = bitmask_size / sizeof (unsigned long);
117 /* skip over leading zeros */
118 while (bitmask[val-1] == 0 && val > 0)
120 for (i = 0; i < val; ++i) {
121 DISABLE_WARNING_FORMAT_NONLITERAL;
122 log_debug(text, i * BITS_PER_LONG, bitmask[i]);
128 /* pointer devices */
129 static void test_pointers (struct udev_device *dev,
130 const unsigned long* bitmask_ev,
131 const unsigned long* bitmask_abs,
132 const unsigned long* bitmask_key,
133 const unsigned long* bitmask_rel,
138 if (!test_bit (EV_KEY, bitmask_ev)) {
139 if (test_bit (EV_ABS, bitmask_ev) &&
140 test_bit (ABS_X, bitmask_abs) &&
141 test_bit (ABS_Y, bitmask_abs) &&
142 test_bit (ABS_Z, bitmask_abs))
143 udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
147 if (test_bit (EV_ABS, bitmask_ev) &&
148 test_bit (ABS_X, bitmask_abs) && test_bit (ABS_Y, bitmask_abs)) {
149 if (test_bit (BTN_STYLUS, bitmask_key) || test_bit (BTN_TOOL_PEN, bitmask_key))
150 udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
151 else if (test_bit (BTN_TOOL_FINGER, bitmask_key) && !test_bit (BTN_TOOL_PEN, bitmask_key))
153 else if (test_bit (BTN_MOUSE, bitmask_key))
154 /* This path is taken by VMware's USB mouse, which has
155 * absolute axes, but no touch/pressure button. */
157 else if (test_bit (BTN_TOUCH, bitmask_key))
158 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
159 /* joysticks don't necessarily have to have buttons; e. g.
160 * rudders/pedals are joystick-like, but buttonless; they have
161 * other fancy axes */
162 else if (test_bit (BTN_TRIGGER, bitmask_key) ||
163 test_bit (BTN_A, bitmask_key) ||
164 test_bit (BTN_1, bitmask_key) ||
165 test_bit (ABS_RX, bitmask_abs) ||
166 test_bit (ABS_RY, bitmask_abs) ||
167 test_bit (ABS_RZ, bitmask_abs) ||
168 test_bit (ABS_THROTTLE, bitmask_abs) ||
169 test_bit (ABS_RUDDER, bitmask_abs) ||
170 test_bit (ABS_WHEEL, bitmask_abs) ||
171 test_bit (ABS_GAS, bitmask_abs) ||
172 test_bit (ABS_BRAKE, bitmask_abs))
173 udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
176 if (test_bit (EV_REL, bitmask_ev) &&
177 test_bit (REL_X, bitmask_rel) && test_bit (REL_Y, bitmask_rel) &&
178 test_bit (BTN_MOUSE, bitmask_key))
182 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
184 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
187 /* key like devices */
188 static void test_key (struct udev_device *dev,
189 const unsigned long* bitmask_ev,
190 const unsigned long* bitmask_key,
196 /* do we have any KEY_* capability? */
197 if (!test_bit (EV_KEY, bitmask_ev)) {
198 log_debug("test_key: no EV_KEY capability");
202 /* only consider KEY_* here, not BTN_* */
204 for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
205 found |= bitmask_key[i];
206 log_debug("test_key: checking bit block %lu for any keys; found=%i", (unsigned long)i*BITS_PER_LONG, found > 0);
208 /* If there are no keys in the lower block, check the higher block */
210 for (i = KEY_OK; i < BTN_TRIGGER_HAPPY; ++i) {
211 if (test_bit (i, bitmask_key)) {
212 log_debug("test_key: Found key %x in high block", i);
220 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
222 /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
223 * those, consider it a full keyboard; do not test KEY_RESERVED, though */
225 if ((bitmask_key[0] & mask) == mask)
226 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
229 static int builtin_input_id(struct udev_device *dev, int argc, char *argv[], bool test) {
230 struct udev_device *pdev;
231 unsigned long bitmask_ev[NBITS(EV_MAX)];
232 unsigned long bitmask_abs[NBITS(ABS_MAX)];
233 unsigned long bitmask_key[NBITS(KEY_MAX)];
234 unsigned long bitmask_rel[NBITS(REL_MAX)];
235 const char *sysname, *devnode;
237 /* walk up the parental chain until we find the real input device; the
238 * argument is very likely a subdevice of this, like eventN */
240 while (pdev != NULL && udev_device_get_sysattr_value(pdev, "capabilities/ev") == NULL)
241 pdev = udev_device_get_parent_with_subsystem_devtype(pdev, "input", NULL);
244 /* Use this as a flag that input devices were detected, so that this
245 * program doesn't need to be called more than once per device */
246 udev_builtin_add_property(dev, test, "ID_INPUT", "1");
247 get_cap_mask(dev, pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
248 get_cap_mask(dev, pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
249 get_cap_mask(dev, pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
250 get_cap_mask(dev, pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
251 test_pointers(dev, bitmask_ev, bitmask_abs, bitmask_key, bitmask_rel, test);
252 test_key(dev, bitmask_ev, bitmask_key, test);
255 devnode = udev_device_get_devnode(dev);
256 sysname = udev_device_get_sysname(dev);
257 if (devnode && sysname && startswith(sysname, "event"))
258 extract_info(dev, devnode, test);
263 const struct udev_builtin udev_builtin_input_id = {
265 .cmd = builtin_input_id,
266 .help = "Input device properties",