1 // SPDX-License-Identifier: MIT
2 /*
3 * Copyright © 2014 Red Hat, Inc.
4 */
5
6 #include "config.h"
7
8 #include <errno.h>
9 #include <fcntl.h>
10 #include <libgen.h>
11 #include <limits.h>
12 #include <math.h>
13 #include <poll.h>
14 #include <signal.h>
15 #include <stdint.h>
16 #include <stdio.h>
17 #include <stdlib.h>
18 #include <string.h>
19 #include <unistd.h>
20
21 #include "libevdev/libevdev.h"
22
23 #define min(a, b) (((a) < (b)) ? (a) : (b))
24 #define max(a, b) (((a) > (b)) ? (a) : (b))
25
26 static int signalled = 0;
27
28 static int
usage(const char * progname)29 usage(const char *progname) {
30 printf("Usage: %s 12x34 /dev/input/eventX\n", progname);
31 printf("\n");
32 printf("This tool reads the touchpad events from the kernel and calculates\n "
33 "the minimum and maximum for the x and y coordinates, respectively.\n"
34 "The first argument is the physical size of the touchpad in mm (WIDTHxHEIGHT).\n");
35 return 1;
36 }
37
38 struct dimensions {
39 int top, bottom, left, right;
40 };
41
42 struct size {
43 int w, h;
44 };
45
46 static int
print_current_values(const struct dimensions * d)47 print_current_values(const struct dimensions *d)
48 {
49 static int progress;
50 char status = 0;
51
52 switch (progress) {
53 case 0: status = '|'; break;
54 case 1: status = '/'; break;
55 case 2: status = '-'; break;
56 case 3: status = '\\'; break;
57 }
58
59 progress = (progress + 1) % 4;
60
61 printf("\rTouchpad sends: x [%d..%d], y [%d..%d] %c",
62 d->left, d->right, d->top, d->bottom, status);
63 return 0;
64 }
65
66 static int
handle_event(struct dimensions * d,const struct input_event * ev)67 handle_event(struct dimensions *d, const struct input_event *ev) {
68 if (ev->type == EV_SYN)
69 return print_current_values(d);
70
71 if (ev->type != EV_ABS)
72 return 0;
73
74 switch(ev->code) {
75 case ABS_X:
76 case ABS_MT_POSITION_X:
77 d->left = min(d->left, ev->value);
78 d->right = max(d->right, ev->value);
79 break;
80 case ABS_Y:
81 case ABS_MT_POSITION_Y:
82 d->top = min(d->top, ev->value);
83 d->bottom = max(d->bottom, ev->value);
84 break;
85 }
86
87 return 0;
88 }
89
90 static void
signal_handler(int signal)91 signal_handler(__attribute__((__unused__)) int signal)
92 {
93 signalled++;
94 }
95
96 static int
mainloop(struct libevdev * dev,struct dimensions * dim)97 mainloop(struct libevdev *dev, struct dimensions *dim) {
98 struct pollfd fds;
99
100 fds.fd = libevdev_get_fd(dev);
101 fds.events = POLLIN;
102
103 signal(SIGINT, signal_handler);
104
105 while (poll(&fds, 1, -1)) {
106 struct input_event ev;
107 int rc;
108
109 if (signalled)
110 break;
111
112 do {
113 rc = libevdev_next_event(dev, LIBEVDEV_READ_FLAG_NORMAL, &ev);
114 if (rc == LIBEVDEV_READ_STATUS_SYNC) {
115 fprintf(stderr, "Error: cannot keep up\n");
116 return 1;
117 }
118
119 if (rc != -EAGAIN && rc < 0) {
120 fprintf(stderr, "Error: %s\n", strerror(-rc));
121 return 1;
122
123 }
124
125 if (rc == LIBEVDEV_READ_STATUS_SUCCESS)
126 handle_event(dim, &ev);
127 } while (rc != -EAGAIN);
128 }
129
130 return 0;
131 }
132
133 static inline void
pid_vid_matchstr(struct libevdev * dev,char * match,size_t sz)134 pid_vid_matchstr(struct libevdev *dev, char *match, size_t sz)
135 {
136 snprintf(match, sz, "input:b%04Xv%04Xp%04X",
137 libevdev_get_id_bustype(dev),
138 libevdev_get_id_vendor(dev),
139 libevdev_get_id_product(dev));
140 }
141
142 static inline void
dmi_matchstr(struct libevdev * dev,char * match,size_t sz)143 dmi_matchstr(struct libevdev *dev, char *match, size_t sz)
144 {
145 char modalias[PATH_MAX];
146 FILE *fp;
147
148 fp = fopen("/sys/class/dmi/id/modalias", "r");
149 if (!fp || fgets(modalias, sizeof(modalias), fp) == NULL) {
150 sprintf(match, "ERROR READING DMI MODALIAS");
151 if (fp)
152 fclose(fp);
153 return;
154 }
155
156 fclose(fp);
157
158 modalias[strlen(modalias) - 1] = '\0'; /* drop \n */
159 snprintf(match, sz, "name:%s:%s", libevdev_get_name(dev), modalias);
160 }
161
162 static void
print_udev_override_rule(struct libevdev * dev,const struct dimensions * dim,const struct size * size)163 print_udev_override_rule(struct libevdev *dev,
164 const struct dimensions *dim,
165 const struct size *size) {
166 const struct input_absinfo *x, *y;
167 char match[PATH_MAX];
168 int w, h;
169 int xres, yres;
170
171 x = libevdev_get_abs_info(dev, ABS_X);
172 y = libevdev_get_abs_info(dev, ABS_Y);
173 w = dim->right - dim->left;
174 h = dim->bottom - dim->top;
175 xres = round((double)w/size->w);
176 yres = round((double)h/size->h);
177
178 if (x->resolution && y->resolution) {
179 int width = x->maximum - x->minimum,
180 height = y->maximum - y->minimum;
181 printf("Touchpad size as listed by the kernel: %dx%dmm\n",
182 width/x->resolution, height/y->resolution);
183 } else {
184 printf("Touchpad has no resolution, size unknown\n");
185 }
186
187 printf("User-specified touchpad size: %dx%dmm\n", size->w, size->h);
188 printf("Calculated ranges: %d/%d\n", w, h);
189 printf("\n");
190 printf("Suggested udev rule:\n");
191
192 switch(libevdev_get_id_bustype(dev)) {
193 case BUS_USB:
194 case BUS_BLUETOOTH:
195 pid_vid_matchstr(dev, match, sizeof(match));
196 break;
197 default:
198 dmi_matchstr(dev, match, sizeof(match));
199 break;
200 }
201
202 printf("# <Laptop model description goes here>\n"
203 "evdev:%s*\n"
204 " EVDEV_ABS_00=%d:%d:%d\n"
205 " EVDEV_ABS_01=%d:%d:%d\n",
206 match,
207 dim->left, dim->right, xres,
208 dim->top, dim->bottom, yres);
209 if (libevdev_has_event_code(dev, EV_ABS, ABS_MT_POSITION_X))
210 printf(" EVDEV_ABS_35=%d:%d:%d\n"
211 " EVDEV_ABS_36=%d:%d:%d\n",
212 dim->left, dim->right, xres,
213 dim->top, dim->bottom, yres);
214 }
215
main(int argc,char ** argv)216 int main (int argc, char **argv) {
217 int rc;
218 int fd;
219 const char *path;
220 struct libevdev *dev;
221 struct dimensions dim;
222 struct size size;
223
224 if (argc < 3)
225 return usage(basename(argv[0]));
226
227 if (sscanf(argv[1], "%dx%d", &size.w, &size.h) != 2 ||
228 size.w <= 0 || size.h <= 0)
229 return usage(basename(argv[0]));
230
231 if (size.w < 30 || size.h < 30) {
232 fprintf(stderr,
233 "%dx%dmm is too small for a touchpad.\n"
234 "Please specify the touchpad size in mm.\n",
235 size.w, size.h);
236 return 1;
237 }
238
239 path = argv[2];
240 if (path[0] == '-')
241 return usage(basename(argv[0]));
242
243 fd = open(path, O_RDONLY|O_NONBLOCK);
244 if (fd < 0) {
245 fprintf(stderr, "Error opening the device: %s\n", strerror(errno));
246 return 1;
247 }
248
249 rc = libevdev_new_from_fd(fd, &dev);
250 if (rc != 0) {
251 fprintf(stderr, "Error fetching the device info: %s\n", strerror(-rc));
252 return 1;
253 }
254
255 if (libevdev_grab(dev, LIBEVDEV_GRAB) != 0) {
256 fprintf(stderr, "Error: cannot grab the device, something else is grabbing it.\n");
257 fprintf(stderr, "Use 'fuser -v %s' to find processes with an open fd\n", path);
258 return 1;
259 }
260 libevdev_grab(dev, LIBEVDEV_UNGRAB);
261
262 if (!libevdev_has_event_code(dev, EV_ABS, ABS_X) ||
263 !libevdev_has_event_code(dev, EV_ABS, ABS_Y)) {
264 fprintf(stderr, "Error: this device does not have abs axes\n");
265 rc = EXIT_FAILURE;
266 goto out;
267 }
268
269 dim.left = INT_MAX;
270 dim.right = INT_MIN;
271 dim.top = INT_MAX;
272 dim.bottom = INT_MIN;
273
274 printf("Touchpad %s on %s\n", libevdev_get_name(dev), path);
275 printf("Move one finger around the touchpad to detect the actual edges\n");
276 printf("Kernel says: x [%d..%d], y [%d..%d]\n",
277 libevdev_get_abs_minimum(dev, ABS_X),
278 libevdev_get_abs_maximum(dev, ABS_X),
279 libevdev_get_abs_minimum(dev, ABS_Y),
280 libevdev_get_abs_maximum(dev, ABS_Y));
281
282 setbuf(stdout, NULL);
283
284 rc = mainloop(dev, &dim);
285 printf("\n\n");
286
287 print_udev_override_rule(dev, &dim, &size);
288
289 out:
290 libevdev_free(dev);
291 close(fd);
292
293 return rc;
294 }
295