summaryrefslogtreecommitdiff
path: root/udev/udev-builtin-input_id.c
blob: 4ef060d899925462811e43e9467ff885c73d22cb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
/*
 * compose persistent device path
 *
 * Copyright (C) 2009 Martin Pitt <martin.pitt@ubuntu.com>
 * Portions Copyright (C) 2004 David Zeuthen, <david@fubar.dk>
 * Copyright (C) 2011 Kay Sievers <kay.sievers@vrfy.org>
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <linux/limits.h>
#include <linux/input.h>

#include "udev.h"

/* we must use this kernel-compatible implementation */
#define BITS_PER_LONG (sizeof(unsigned long) * 8)
#define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
#define OFF(x)  ((x)%BITS_PER_LONG)
#define BIT(x)  (1UL<<OFF(x))
#define LONG(x) ((x)/BITS_PER_LONG)
#define test_bit(bit, array)    ((array[LONG(bit)] >> OFF(bit)) & 1)

/*
 * Read a capability attribute and return bitmask.
 * @param dev udev_device
 * @param attr sysfs attribute name (e. g. "capabilities/key")
 * @param bitmask: Output array which has a sizeof of bitmask_size
 */
static void get_cap_mask(struct udev_device *dev,
			 struct udev_device *pdev, const char* attr,
			 unsigned long *bitmask, size_t bitmask_size,
			 bool test)
{
	struct udev *udev = udev_device_get_udev(dev);
	char text[4096];
	unsigned i;
	char* word;
	unsigned long val;

	snprintf(text, sizeof(text), "%s", udev_device_get_sysattr_value(pdev, attr));
	info(udev, "%s raw kernel attribute: %s\n", attr, text);

	memset (bitmask, 0, bitmask_size);
	i = 0;
	while ((word = strrchr(text, ' ')) != NULL) {
		val = strtoul (word+1, NULL, 16);
		if (i < bitmask_size/sizeof(unsigned long))
			bitmask[i] = val;
		else
			info(udev, "ignoring %s block %lX which is larger than maximum size\n", attr, val);
		*word = '\0';
		++i;
	}
	val = strtoul (text, NULL, 16);
	if (i < bitmask_size / sizeof(unsigned long))
		bitmask[i] = val;
	else
		info(udev, "ignoring %s block %lX which is larger than maximum size\n", attr, val);

	if (test) {
		/* printf pattern with the right unsigned long number of hex chars */
		snprintf(text, sizeof(text), "  bit %%4u: %%0%zilX\n", 2 * sizeof(unsigned long));
		info(udev, "%s decoded bit map:\n", attr);
		val = bitmask_size / sizeof (unsigned long);
		/* skip over leading zeros */
		while (bitmask[val-1] == 0 && val > 0)
			--val;
		for (i = 0; i < val; ++i)
			info(udev, text, i * BITS_PER_LONG, bitmask[i]);
	}
}

/* pointer devices */
static void test_pointers (struct udev_device *dev,
			   const unsigned long* bitmask_ev,
			   const unsigned long* bitmask_abs,
			   const unsigned long* bitmask_key,
			   const unsigned long* bitmask_rel,
			   bool test)
{
	int is_mouse = 0;
	int is_touchpad = 0;

	if (!test_bit (EV_KEY, bitmask_ev)) {
		if (test_bit (EV_ABS, bitmask_ev) &&
		    test_bit (ABS_X, bitmask_abs) &&
		    test_bit (ABS_Y, bitmask_abs) &&
		    test_bit (ABS_Z, bitmask_abs))
			udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
		return;
	}

	if (test_bit (EV_ABS, bitmask_ev) &&
	    test_bit (ABS_X, bitmask_abs) && test_bit (ABS_Y, bitmask_abs)) {
		if (test_bit (BTN_STYLUS, bitmask_key) || test_bit (BTN_TOOL_PEN, bitmask_key))
			udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
		else if (test_bit (BTN_TOOL_FINGER, bitmask_key) && !test_bit (BTN_TOOL_PEN, bitmask_key))
			is_touchpad = 1;
		else if (test_bit (BTN_TRIGGER, bitmask_key) || 
			 test_bit (BTN_A, bitmask_key) || 
			 test_bit (BTN_1, bitmask_key))
			udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
		else if (test_bit (BTN_MOUSE, bitmask_key))
			/* This path is taken by VMware's USB mouse, which has
			 * absolute axes, but no touch/pressure button. */
			is_mouse = 1;
		else if (test_bit (BTN_TOUCH, bitmask_key))
			udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
	}

	if (test_bit (EV_REL, bitmask_ev) && 
	    test_bit (REL_X, bitmask_rel) && test_bit (REL_Y, bitmask_rel) &&
	    test_bit (BTN_MOUSE, bitmask_key))
		is_mouse = 1;

	if (is_mouse)
		udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
	if (is_touchpad)
		udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
}

/* key like devices */
static void test_key (struct udev_device *dev,
		      const unsigned long* bitmask_ev,
		      const unsigned long* bitmask_key,
		      bool test)
{
	struct udev *udev = udev_device_get_udev(dev);
	unsigned i;
	unsigned long found;
	unsigned long mask;

	/* do we have any KEY_* capability? */
	if (!test_bit (EV_KEY, bitmask_ev)) {
		info(udev, "test_key: no EV_KEY capability\n");
		return;
	}

	/* only consider KEY_* here, not BTN_* */
	found = 0;
	for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
		found |= bitmask_key[i];
		info(udev, "test_key: checking bit block %lu for any keys; found=%i\n", i*BITS_PER_LONG, found > 0);
	}
	/* If there are no keys in the lower block, check the higher block */
	if (!found) {
		for (i = KEY_OK; i < BTN_TRIGGER_HAPPY; ++i) {
			if (test_bit (i, bitmask_key)) {
				info(udev, "test_key: Found key %x in high block\n", i);
				found = 1;
				break;
			}
		}
	}

	if (found > 0)
		udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");

	/* the first 32 bits are ESC, numbers, and Q to D; if we have all of
	 * those, consider it a full keyboard; do not test KEY_RESERVED, though */
	mask = 0xFFFFFFFE;
	if ((bitmask_key[0] & mask) == mask)
		udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
}

static int builtin_input_id(struct udev_device *dev, int argc, char *argv[], bool test)
{
	struct udev_device *pdev;
	unsigned long bitmask_ev[NBITS(EV_MAX)];
	unsigned long bitmask_abs[NBITS(ABS_MAX)];
	unsigned long bitmask_key[NBITS(KEY_MAX)];
	unsigned long bitmask_rel[NBITS(REL_MAX)];

	/* walk up the parental chain until we find the real input device; the
	 * argument is very likely a subdevice of this, like eventN */
	pdev = dev;
	while (pdev != NULL && udev_device_get_sysattr_value(pdev, "capabilities/ev") == NULL)
		pdev = udev_device_get_parent_with_subsystem_devtype(pdev, "input", NULL);

	/* not an "input" class device */
	if (pdev == NULL)
		return EXIT_SUCCESS;

	/* Use this as a flag that input devices were detected, so that this
	 * program doesn't need to be called more than once per device */
	udev_builtin_add_property(dev, test, "ID_INPUT", "1");
	get_cap_mask(dev, pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
	get_cap_mask(dev, pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
	get_cap_mask(dev, pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
	get_cap_mask(dev, pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
	test_pointers(dev, bitmask_ev, bitmask_abs, bitmask_key, bitmask_rel, test);
	test_key(dev, bitmask_ev, bitmask_key, test);
	return EXIT_SUCCESS;
}

const struct udev_builtin udev_builtin_input_id = {
	.name = "input_id",
	.cmd = builtin_input_id,
	.help = "input device properties",
};