]>
Commit | Line | Data |
---|---|---|
71adf118 FC |
1 | |
2 | Linux USB HID gadget driver | |
3 | ||
4 | Introduction | |
5 | ||
6 | The HID Gadget driver provides emulation of USB Human Interface | |
7 | Devices (HID). The basic HID handling is done in the kernel, | |
8 | and HID reports can be sent/received through I/O on the | |
9 | /dev/hidgX character devices. | |
10 | ||
11 | For more details about HID, see the developer page on | |
12 | http://www.usb.org/developers/hidpage/ | |
13 | ||
14 | Configuration | |
15 | ||
16 | g_hid is a platform driver, so to use it you need to add | |
17 | struct platform_device(s) to your platform code defining the | |
18 | HID function descriptors you want to use - E.G. something | |
19 | like: | |
20 | ||
21 | #include <linux/platform_device.h> | |
22 | #include <linux/usb/g_hid.h> | |
23 | ||
24 | /* hid descriptor for a keyboard */ | |
25 | static struct hidg_func_descriptor my_hid_data = { | |
26 | .subclass = 0, /* No subclass */ | |
27 | .protocol = 1, /* Keyboard */ | |
28 | .report_length = 8, | |
29 | .report_desc_length = 63, | |
30 | .report_desc = { | |
31 | 0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */ | |
32 | 0x09, 0x06, /* USAGE (Keyboard) */ | |
33 | 0xa1, 0x01, /* COLLECTION (Application) */ | |
34 | 0x05, 0x07, /* USAGE_PAGE (Keyboard) */ | |
35 | 0x19, 0xe0, /* USAGE_MINIMUM (Keyboard LeftControl) */ | |
36 | 0x29, 0xe7, /* USAGE_MAXIMUM (Keyboard Right GUI) */ | |
37 | 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ | |
38 | 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */ | |
39 | 0x75, 0x01, /* REPORT_SIZE (1) */ | |
40 | 0x95, 0x08, /* REPORT_COUNT (8) */ | |
41 | 0x81, 0x02, /* INPUT (Data,Var,Abs) */ | |
42 | 0x95, 0x01, /* REPORT_COUNT (1) */ | |
43 | 0x75, 0x08, /* REPORT_SIZE (8) */ | |
44 | 0x81, 0x03, /* INPUT (Cnst,Var,Abs) */ | |
45 | 0x95, 0x05, /* REPORT_COUNT (5) */ | |
46 | 0x75, 0x01, /* REPORT_SIZE (1) */ | |
47 | 0x05, 0x08, /* USAGE_PAGE (LEDs) */ | |
48 | 0x19, 0x01, /* USAGE_MINIMUM (Num Lock) */ | |
49 | 0x29, 0x05, /* USAGE_MAXIMUM (Kana) */ | |
50 | 0x91, 0x02, /* OUTPUT (Data,Var,Abs) */ | |
51 | 0x95, 0x01, /* REPORT_COUNT (1) */ | |
52 | 0x75, 0x03, /* REPORT_SIZE (3) */ | |
53 | 0x91, 0x03, /* OUTPUT (Cnst,Var,Abs) */ | |
54 | 0x95, 0x06, /* REPORT_COUNT (6) */ | |
55 | 0x75, 0x08, /* REPORT_SIZE (8) */ | |
56 | 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ | |
57 | 0x25, 0x65, /* LOGICAL_MAXIMUM (101) */ | |
58 | 0x05, 0x07, /* USAGE_PAGE (Keyboard) */ | |
59 | 0x19, 0x00, /* USAGE_MINIMUM (Reserved) */ | |
60 | 0x29, 0x65, /* USAGE_MAXIMUM (Keyboard Application) */ | |
61 | 0x81, 0x00, /* INPUT (Data,Ary,Abs) */ | |
62 | 0xc0 /* END_COLLECTION */ | |
63 | } | |
64 | }; | |
65 | ||
66 | static struct platform_device my_hid = { | |
67 | .name = "hidg", | |
68 | .id = 0, | |
69 | .num_resources = 0, | |
70 | .resource = 0, | |
71 | .dev.platform_data = &my_hid_data, | |
72 | }; | |
73 | ||
74 | You can add as many HID functions as you want, only limited by | |
75 | the amount of interrupt endpoints your gadget driver supports. | |
76 | ||
21a9476a AP |
77 | Configuration with configfs |
78 | ||
79 | Instead of adding fake platform devices and drivers in order to pass | |
80 | some data to the kernel, if HID is a part of a gadget composed with | |
81 | configfs the hidg_func_descriptor.report_desc is passed to the kernel | |
82 | by writing the appropriate stream of bytes to a configfs attribute. | |
83 | ||
71adf118 FC |
84 | Send and receive HID reports |
85 | ||
86 | HID reports can be sent/received using read/write on the | |
87 | /dev/hidgX character devices. See below for an example program | |
88 | to do this. | |
89 | ||
90 | hid_gadget_test is a small interactive program to test the HID | |
6e7be1a0 TK |
91 | gadget driver. To use, point it at a hidg device and set the |
92 | device type (keyboard / mouse / joystick) - E.G.: | |
71adf118 FC |
93 | |
94 | # hid_gadget_test /dev/hidg0 keyboard | |
95 | ||
96 | You are now in the prompt of hid_gadget_test. You can type any | |
97 | combination of options and values. Available options and | |
98 | values are listed at program start. In keyboard mode you can | |
99 | send up to six values. | |
100 | ||
101 | For example type: g i s t r --left-shift | |
102 | ||
103 | Hit return and the corresponding report will be sent by the | |
104 | HID gadget. | |
105 | ||
106 | Another interesting example is the caps lock test. Type | |
6e7be1a0 | 107 | --caps-lock and hit return. A report is then sent by the |
71adf118 FC |
108 | gadget and you should receive the host answer, corresponding |
109 | to the caps lock LED status. | |
110 | ||
111 | --caps-lock | |
112 | recv report:2 | |
113 | ||
114 | With this command: | |
115 | ||
116 | # hid_gadget_test /dev/hidg1 mouse | |
117 | ||
118 | You can test the mouse emulation. Values are two signed numbers. | |
119 | ||
120 | ||
121 | Sample code | |
122 | ||
123 | /* hid_gadget_test */ | |
124 | ||
125 | #include <pthread.h> | |
126 | #include <string.h> | |
127 | #include <stdio.h> | |
128 | #include <ctype.h> | |
129 | #include <fcntl.h> | |
130 | #include <errno.h> | |
131 | #include <stdio.h> | |
132 | #include <stdlib.h> | |
133 | #include <unistd.h> | |
134 | ||
135 | #define BUF_LEN 512 | |
136 | ||
137 | struct options { | |
138 | const char *opt; | |
139 | unsigned char val; | |
140 | }; | |
141 | ||
142 | static struct options kmod[] = { | |
143 | {.opt = "--left-ctrl", .val = 0x01}, | |
144 | {.opt = "--right-ctrl", .val = 0x10}, | |
145 | {.opt = "--left-shift", .val = 0x02}, | |
146 | {.opt = "--right-shift", .val = 0x20}, | |
147 | {.opt = "--left-alt", .val = 0x04}, | |
148 | {.opt = "--right-alt", .val = 0x40}, | |
149 | {.opt = "--left-meta", .val = 0x08}, | |
150 | {.opt = "--right-meta", .val = 0x80}, | |
151 | {.opt = NULL} | |
152 | }; | |
153 | ||
154 | static struct options kval[] = { | |
155 | {.opt = "--return", .val = 0x28}, | |
156 | {.opt = "--esc", .val = 0x29}, | |
157 | {.opt = "--bckspc", .val = 0x2a}, | |
158 | {.opt = "--tab", .val = 0x2b}, | |
159 | {.opt = "--spacebar", .val = 0x2c}, | |
160 | {.opt = "--caps-lock", .val = 0x39}, | |
161 | {.opt = "--f1", .val = 0x3a}, | |
162 | {.opt = "--f2", .val = 0x3b}, | |
163 | {.opt = "--f3", .val = 0x3c}, | |
164 | {.opt = "--f4", .val = 0x3d}, | |
165 | {.opt = "--f5", .val = 0x3e}, | |
166 | {.opt = "--f6", .val = 0x3f}, | |
167 | {.opt = "--f7", .val = 0x40}, | |
168 | {.opt = "--f8", .val = 0x41}, | |
169 | {.opt = "--f9", .val = 0x42}, | |
170 | {.opt = "--f10", .val = 0x43}, | |
171 | {.opt = "--f11", .val = 0x44}, | |
172 | {.opt = "--f12", .val = 0x45}, | |
173 | {.opt = "--insert", .val = 0x49}, | |
174 | {.opt = "--home", .val = 0x4a}, | |
175 | {.opt = "--pageup", .val = 0x4b}, | |
176 | {.opt = "--del", .val = 0x4c}, | |
177 | {.opt = "--end", .val = 0x4d}, | |
178 | {.opt = "--pagedown", .val = 0x4e}, | |
179 | {.opt = "--right", .val = 0x4f}, | |
180 | {.opt = "--left", .val = 0x50}, | |
181 | {.opt = "--down", .val = 0x51}, | |
182 | {.opt = "--kp-enter", .val = 0x58}, | |
183 | {.opt = "--up", .val = 0x52}, | |
184 | {.opt = "--num-lock", .val = 0x53}, | |
185 | {.opt = NULL} | |
186 | }; | |
187 | ||
188 | int keyboard_fill_report(char report[8], char buf[BUF_LEN], int *hold) | |
189 | { | |
190 | char *tok = strtok(buf, " "); | |
191 | int key = 0; | |
192 | int i = 0; | |
193 | ||
194 | for (; tok != NULL; tok = strtok(NULL, " ")) { | |
195 | ||
196 | if (strcmp(tok, "--quit") == 0) | |
197 | return -1; | |
198 | ||
199 | if (strcmp(tok, "--hold") == 0) { | |
200 | *hold = 1; | |
201 | continue; | |
202 | } | |
203 | ||
204 | if (key < 6) { | |
205 | for (i = 0; kval[i].opt != NULL; i++) | |
206 | if (strcmp(tok, kval[i].opt) == 0) { | |
207 | report[2 + key++] = kval[i].val; | |
208 | break; | |
209 | } | |
210 | if (kval[i].opt != NULL) | |
211 | continue; | |
212 | } | |
213 | ||
214 | if (key < 6) | |
215 | if (islower(tok[0])) { | |
216 | report[2 + key++] = (tok[0] - ('a' - 0x04)); | |
217 | continue; | |
218 | } | |
219 | ||
220 | for (i = 0; kmod[i].opt != NULL; i++) | |
221 | if (strcmp(tok, kmod[i].opt) == 0) { | |
222 | report[0] = report[0] | kmod[i].val; | |
223 | break; | |
224 | } | |
225 | if (kmod[i].opt != NULL) | |
226 | continue; | |
227 | ||
228 | if (key < 6) | |
229 | fprintf(stderr, "unknown option: %s\n", tok); | |
230 | } | |
231 | return 8; | |
232 | } | |
233 | ||
234 | static struct options mmod[] = { | |
235 | {.opt = "--b1", .val = 0x01}, | |
236 | {.opt = "--b2", .val = 0x02}, | |
237 | {.opt = "--b3", .val = 0x04}, | |
238 | {.opt = NULL} | |
239 | }; | |
240 | ||
241 | int mouse_fill_report(char report[8], char buf[BUF_LEN], int *hold) | |
242 | { | |
243 | char *tok = strtok(buf, " "); | |
244 | int mvt = 0; | |
245 | int i = 0; | |
246 | for (; tok != NULL; tok = strtok(NULL, " ")) { | |
247 | ||
248 | if (strcmp(tok, "--quit") == 0) | |
249 | return -1; | |
250 | ||
251 | if (strcmp(tok, "--hold") == 0) { | |
252 | *hold = 1; | |
253 | continue; | |
254 | } | |
255 | ||
256 | for (i = 0; mmod[i].opt != NULL; i++) | |
257 | if (strcmp(tok, mmod[i].opt) == 0) { | |
258 | report[0] = report[0] | mmod[i].val; | |
259 | break; | |
260 | } | |
261 | if (mmod[i].opt != NULL) | |
262 | continue; | |
263 | ||
264 | if (!(tok[0] == '-' && tok[1] == '-') && mvt < 2) { | |
265 | errno = 0; | |
266 | report[1 + mvt++] = (char)strtol(tok, NULL, 0); | |
267 | if (errno != 0) { | |
268 | fprintf(stderr, "Bad value:'%s'\n", tok); | |
269 | report[1 + mvt--] = 0; | |
270 | } | |
271 | continue; | |
272 | } | |
273 | ||
274 | fprintf(stderr, "unknown option: %s\n", tok); | |
275 | } | |
276 | return 3; | |
277 | } | |
278 | ||
279 | static struct options jmod[] = { | |
280 | {.opt = "--b1", .val = 0x10}, | |
281 | {.opt = "--b2", .val = 0x20}, | |
282 | {.opt = "--b3", .val = 0x40}, | |
283 | {.opt = "--b4", .val = 0x80}, | |
284 | {.opt = "--hat1", .val = 0x00}, | |
285 | {.opt = "--hat2", .val = 0x01}, | |
286 | {.opt = "--hat3", .val = 0x02}, | |
287 | {.opt = "--hat4", .val = 0x03}, | |
288 | {.opt = "--hatneutral", .val = 0x04}, | |
289 | {.opt = NULL} | |
290 | }; | |
291 | ||
292 | int joystick_fill_report(char report[8], char buf[BUF_LEN], int *hold) | |
293 | { | |
294 | char *tok = strtok(buf, " "); | |
295 | int mvt = 0; | |
296 | int i = 0; | |
297 | ||
298 | *hold = 1; | |
299 | ||
300 | /* set default hat position: neutral */ | |
301 | report[3] = 0x04; | |
302 | ||
303 | for (; tok != NULL; tok = strtok(NULL, " ")) { | |
304 | ||
305 | if (strcmp(tok, "--quit") == 0) | |
306 | return -1; | |
307 | ||
308 | for (i = 0; jmod[i].opt != NULL; i++) | |
309 | if (strcmp(tok, jmod[i].opt) == 0) { | |
310 | report[3] = (report[3] & 0xF0) | jmod[i].val; | |
311 | break; | |
312 | } | |
313 | if (jmod[i].opt != NULL) | |
314 | continue; | |
315 | ||
316 | if (!(tok[0] == '-' && tok[1] == '-') && mvt < 3) { | |
317 | errno = 0; | |
318 | report[mvt++] = (char)strtol(tok, NULL, 0); | |
319 | if (errno != 0) { | |
320 | fprintf(stderr, "Bad value:'%s'\n", tok); | |
321 | report[mvt--] = 0; | |
322 | } | |
323 | continue; | |
324 | } | |
325 | ||
326 | fprintf(stderr, "unknown option: %s\n", tok); | |
327 | } | |
328 | return 4; | |
329 | } | |
330 | ||
331 | void print_options(char c) | |
332 | { | |
333 | int i = 0; | |
334 | ||
335 | if (c == 'k') { | |
336 | printf(" keyboard options:\n" | |
337 | " --hold\n"); | |
338 | for (i = 0; kmod[i].opt != NULL; i++) | |
339 | printf("\t\t%s\n", kmod[i].opt); | |
340 | printf("\n keyboard values:\n" | |
341 | " [a-z] or\n"); | |
342 | for (i = 0; kval[i].opt != NULL; i++) | |
343 | printf("\t\t%-8s%s", kval[i].opt, i % 2 ? "\n" : ""); | |
344 | printf("\n"); | |
345 | } else if (c == 'm') { | |
346 | printf(" mouse options:\n" | |
347 | " --hold\n"); | |
348 | for (i = 0; mmod[i].opt != NULL; i++) | |
349 | printf("\t\t%s\n", mmod[i].opt); | |
350 | printf("\n mouse values:\n" | |
351 | " Two signed numbers\n" | |
352 | "--quit to close\n"); | |
353 | } else { | |
354 | printf(" joystick options:\n"); | |
355 | for (i = 0; jmod[i].opt != NULL; i++) | |
356 | printf("\t\t%s\n", jmod[i].opt); | |
357 | printf("\n joystick values:\n" | |
358 | " three signed numbers\n" | |
359 | "--quit to close\n"); | |
360 | } | |
361 | } | |
362 | ||
363 | int main(int argc, const char *argv[]) | |
364 | { | |
365 | const char *filename = NULL; | |
366 | int fd = 0; | |
367 | char buf[BUF_LEN]; | |
368 | int cmd_len; | |
369 | char report[8]; | |
370 | int to_send = 8; | |
371 | int hold = 0; | |
372 | fd_set rfds; | |
373 | int retval, i; | |
374 | ||
375 | if (argc < 3) { | |
376 | fprintf(stderr, "Usage: %s devname mouse|keyboard|joystick\n", | |
377 | argv[0]); | |
378 | return 1; | |
379 | } | |
380 | ||
381 | if (argv[2][0] != 'k' && argv[2][0] != 'm' && argv[2][0] != 'j') | |
382 | return 2; | |
383 | ||
384 | filename = argv[1]; | |
385 | ||
386 | if ((fd = open(filename, O_RDWR, 0666)) == -1) { | |
387 | perror(filename); | |
388 | return 3; | |
389 | } | |
390 | ||
391 | print_options(argv[2][0]); | |
392 | ||
393 | while (42) { | |
394 | ||
395 | FD_ZERO(&rfds); | |
396 | FD_SET(STDIN_FILENO, &rfds); | |
397 | FD_SET(fd, &rfds); | |
398 | ||
399 | retval = select(fd + 1, &rfds, NULL, NULL, NULL); | |
400 | if (retval == -1 && errno == EINTR) | |
401 | continue; | |
402 | if (retval < 0) { | |
403 | perror("select()"); | |
404 | return 4; | |
405 | } | |
406 | ||
407 | if (FD_ISSET(fd, &rfds)) { | |
408 | cmd_len = read(fd, buf, BUF_LEN - 1); | |
409 | printf("recv report:"); | |
410 | for (i = 0; i < cmd_len; i++) | |
411 | printf(" %02x", buf[i]); | |
412 | printf("\n"); | |
413 | } | |
414 | ||
415 | if (FD_ISSET(STDIN_FILENO, &rfds)) { | |
416 | memset(report, 0x0, sizeof(report)); | |
417 | cmd_len = read(STDIN_FILENO, buf, BUF_LEN - 1); | |
418 | ||
419 | if (cmd_len == 0) | |
420 | break; | |
421 | ||
422 | buf[cmd_len - 1] = '\0'; | |
423 | hold = 0; | |
424 | ||
425 | memset(report, 0x0, sizeof(report)); | |
426 | if (argv[2][0] == 'k') | |
427 | to_send = keyboard_fill_report(report, buf, &hold); | |
428 | else if (argv[2][0] == 'm') | |
429 | to_send = mouse_fill_report(report, buf, &hold); | |
430 | else | |
431 | to_send = joystick_fill_report(report, buf, &hold); | |
432 | ||
433 | if (to_send == -1) | |
434 | break; | |
435 | ||
436 | if (write(fd, report, to_send) != to_send) { | |
437 | perror(filename); | |
438 | return 5; | |
439 | } | |
440 | if (!hold) { | |
441 | memset(report, 0x0, sizeof(report)); | |
442 | if (write(fd, report, to_send) != to_send) { | |
443 | perror(filename); | |
444 | return 6; | |
445 | } | |
446 | } | |
447 | } | |
448 | } | |
449 | ||
450 | close(fd); | |
451 | return 0; | |
452 | } |