Commit | Line | Data |
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1ccd7a2a DH |
1 | /* |
2 | * User-space I/O driver support for HID subsystem | |
3 | * Copyright (c) 2012 David Herrmann | |
4 | */ | |
5 | ||
6 | /* | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License as published by the Free | |
9 | * Software Foundation; either version 2 of the License, or (at your option) | |
10 | * any later version. | |
11 | */ | |
12 | ||
13 | #include <linux/atomic.h> | |
befde022 | 14 | #include <linux/compat.h> |
1ccd7a2a DH |
15 | #include <linux/device.h> |
16 | #include <linux/fs.h> | |
17 | #include <linux/hid.h> | |
18 | #include <linux/input.h> | |
19 | #include <linux/miscdevice.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/mutex.h> | |
22 | #include <linux/poll.h> | |
23 | #include <linux/sched.h> | |
24 | #include <linux/spinlock.h> | |
25 | #include <linux/uhid.h> | |
26 | #include <linux/wait.h> | |
27 | ||
28 | #define UHID_NAME "uhid" | |
ace3d861 DH |
29 | #define UHID_BUFSIZE 32 |
30 | ||
31 | struct uhid_device { | |
d937ae5f | 32 | struct mutex devlock; |
d365c6cf DH |
33 | bool running; |
34 | ||
35 | __u8 *rd_data; | |
36 | uint rd_size; | |
37 | ||
ace3d861 | 38 | struct hid_device *hid; |
6664ef72 | 39 | struct uhid_event input_buf; |
ace3d861 DH |
40 | |
41 | wait_queue_head_t waitq; | |
42 | spinlock_t qlock; | |
43 | __u8 head; | |
44 | __u8 tail; | |
45 | struct uhid_event *outq[UHID_BUFSIZE]; | |
fcfcf0de DH |
46 | |
47 | struct mutex report_lock; | |
48 | wait_queue_head_t report_wait; | |
49 | atomic_t report_done; | |
50 | atomic_t report_id; | |
51 | struct uhid_event report_buf; | |
ace3d861 | 52 | }; |
1ccd7a2a DH |
53 | |
54 | static struct miscdevice uhid_misc; | |
55 | ||
ace3d861 DH |
56 | static void uhid_queue(struct uhid_device *uhid, struct uhid_event *ev) |
57 | { | |
58 | __u8 newhead; | |
59 | ||
60 | newhead = (uhid->head + 1) % UHID_BUFSIZE; | |
61 | ||
62 | if (newhead != uhid->tail) { | |
63 | uhid->outq[uhid->head] = ev; | |
64 | uhid->head = newhead; | |
65 | wake_up_interruptible(&uhid->waitq); | |
66 | } else { | |
67 | hid_warn(uhid->hid, "Output queue is full\n"); | |
68 | kfree(ev); | |
69 | } | |
70 | } | |
71 | ||
72 | static int uhid_queue_event(struct uhid_device *uhid, __u32 event) | |
73 | { | |
74 | unsigned long flags; | |
75 | struct uhid_event *ev; | |
76 | ||
77 | ev = kzalloc(sizeof(*ev), GFP_KERNEL); | |
78 | if (!ev) | |
79 | return -ENOMEM; | |
80 | ||
81 | ev->type = event; | |
82 | ||
83 | spin_lock_irqsave(&uhid->qlock, flags); | |
84 | uhid_queue(uhid, ev); | |
85 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
d365c6cf DH |
90 | static int uhid_hid_start(struct hid_device *hid) |
91 | { | |
ec4b7dea DH |
92 | struct uhid_device *uhid = hid->driver_data; |
93 | ||
94 | return uhid_queue_event(uhid, UHID_START); | |
d365c6cf DH |
95 | } |
96 | ||
97 | static void uhid_hid_stop(struct hid_device *hid) | |
98 | { | |
ec4b7dea DH |
99 | struct uhid_device *uhid = hid->driver_data; |
100 | ||
101 | hid->claimed = 0; | |
102 | uhid_queue_event(uhid, UHID_STOP); | |
d365c6cf DH |
103 | } |
104 | ||
105 | static int uhid_hid_open(struct hid_device *hid) | |
106 | { | |
e7191474 DH |
107 | struct uhid_device *uhid = hid->driver_data; |
108 | ||
109 | return uhid_queue_event(uhid, UHID_OPEN); | |
d365c6cf DH |
110 | } |
111 | ||
112 | static void uhid_hid_close(struct hid_device *hid) | |
113 | { | |
e7191474 DH |
114 | struct uhid_device *uhid = hid->driver_data; |
115 | ||
116 | uhid_queue_event(uhid, UHID_CLOSE); | |
d365c6cf DH |
117 | } |
118 | ||
119 | static int uhid_hid_input(struct input_dev *input, unsigned int type, | |
120 | unsigned int code, int value) | |
121 | { | |
f80e1360 DH |
122 | struct hid_device *hid = input_get_drvdata(input); |
123 | struct uhid_device *uhid = hid->driver_data; | |
124 | unsigned long flags; | |
125 | struct uhid_event *ev; | |
126 | ||
127 | ev = kzalloc(sizeof(*ev), GFP_ATOMIC); | |
128 | if (!ev) | |
129 | return -ENOMEM; | |
130 | ||
131 | ev->type = UHID_OUTPUT_EV; | |
132 | ev->u.output_ev.type = type; | |
133 | ev->u.output_ev.code = code; | |
134 | ev->u.output_ev.value = value; | |
135 | ||
136 | spin_lock_irqsave(&uhid->qlock, flags); | |
137 | uhid_queue(uhid, ev); | |
138 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
139 | ||
d365c6cf DH |
140 | return 0; |
141 | } | |
142 | ||
143 | static int uhid_hid_parse(struct hid_device *hid) | |
144 | { | |
037c061b DH |
145 | struct uhid_device *uhid = hid->driver_data; |
146 | ||
147 | return hid_parse_report(hid, uhid->rd_data, uhid->rd_size); | |
d365c6cf DH |
148 | } |
149 | ||
150 | static int uhid_hid_get_raw(struct hid_device *hid, unsigned char rnum, | |
151 | __u8 *buf, size_t count, unsigned char rtype) | |
152 | { | |
fcfcf0de DH |
153 | struct uhid_device *uhid = hid->driver_data; |
154 | __u8 report_type; | |
155 | struct uhid_event *ev; | |
156 | unsigned long flags; | |
157 | int ret; | |
1a8b294c | 158 | size_t uninitialized_var(len); |
fcfcf0de DH |
159 | struct uhid_feature_answer_req *req; |
160 | ||
161 | if (!uhid->running) | |
162 | return -EIO; | |
163 | ||
164 | switch (rtype) { | |
165 | case HID_FEATURE_REPORT: | |
166 | report_type = UHID_FEATURE_REPORT; | |
167 | break; | |
168 | case HID_OUTPUT_REPORT: | |
169 | report_type = UHID_OUTPUT_REPORT; | |
170 | break; | |
171 | case HID_INPUT_REPORT: | |
172 | report_type = UHID_INPUT_REPORT; | |
173 | break; | |
174 | default: | |
175 | return -EINVAL; | |
176 | } | |
177 | ||
178 | ret = mutex_lock_interruptible(&uhid->report_lock); | |
179 | if (ret) | |
180 | return ret; | |
181 | ||
182 | ev = kzalloc(sizeof(*ev), GFP_KERNEL); | |
183 | if (!ev) { | |
184 | ret = -ENOMEM; | |
185 | goto unlock; | |
186 | } | |
187 | ||
188 | spin_lock_irqsave(&uhid->qlock, flags); | |
189 | ev->type = UHID_FEATURE; | |
190 | ev->u.feature.id = atomic_inc_return(&uhid->report_id); | |
191 | ev->u.feature.rnum = rnum; | |
192 | ev->u.feature.rtype = report_type; | |
193 | ||
194 | atomic_set(&uhid->report_done, 0); | |
195 | uhid_queue(uhid, ev); | |
196 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
197 | ||
198 | ret = wait_event_interruptible_timeout(uhid->report_wait, | |
199 | atomic_read(&uhid->report_done), 5 * HZ); | |
200 | ||
201 | /* | |
202 | * Make sure "uhid->running" is cleared on shutdown before | |
203 | * "uhid->report_done" is set. | |
204 | */ | |
205 | smp_rmb(); | |
206 | if (!ret || !uhid->running) { | |
207 | ret = -EIO; | |
208 | } else if (ret < 0) { | |
209 | ret = -ERESTARTSYS; | |
210 | } else { | |
211 | spin_lock_irqsave(&uhid->qlock, flags); | |
212 | req = &uhid->report_buf.u.feature_answer; | |
213 | ||
214 | if (req->err) { | |
215 | ret = -EIO; | |
216 | } else { | |
217 | ret = 0; | |
218 | len = min(count, | |
219 | min_t(size_t, req->size, UHID_DATA_MAX)); | |
220 | memcpy(buf, req->data, len); | |
221 | } | |
222 | ||
223 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
224 | } | |
225 | ||
226 | atomic_set(&uhid->report_done, 1); | |
227 | ||
228 | unlock: | |
229 | mutex_unlock(&uhid->report_lock); | |
230 | return ret ? ret : len; | |
d365c6cf DH |
231 | } |
232 | ||
233 | static int uhid_hid_output_raw(struct hid_device *hid, __u8 *buf, size_t count, | |
234 | unsigned char report_type) | |
235 | { | |
3b3baa82 DH |
236 | struct uhid_device *uhid = hid->driver_data; |
237 | __u8 rtype; | |
238 | unsigned long flags; | |
239 | struct uhid_event *ev; | |
240 | ||
241 | switch (report_type) { | |
242 | case HID_FEATURE_REPORT: | |
243 | rtype = UHID_FEATURE_REPORT; | |
244 | break; | |
245 | case HID_OUTPUT_REPORT: | |
246 | rtype = UHID_OUTPUT_REPORT; | |
247 | break; | |
248 | default: | |
249 | return -EINVAL; | |
250 | } | |
251 | ||
252 | if (count < 1 || count > UHID_DATA_MAX) | |
253 | return -EINVAL; | |
254 | ||
255 | ev = kzalloc(sizeof(*ev), GFP_KERNEL); | |
256 | if (!ev) | |
257 | return -ENOMEM; | |
258 | ||
259 | ev->type = UHID_OUTPUT; | |
260 | ev->u.output.size = count; | |
261 | ev->u.output.rtype = rtype; | |
262 | memcpy(ev->u.output.data, buf, count); | |
263 | ||
264 | spin_lock_irqsave(&uhid->qlock, flags); | |
265 | uhid_queue(uhid, ev); | |
266 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
267 | ||
268 | return count; | |
d365c6cf DH |
269 | } |
270 | ||
271 | static struct hid_ll_driver uhid_hid_driver = { | |
272 | .start = uhid_hid_start, | |
273 | .stop = uhid_hid_stop, | |
274 | .open = uhid_hid_open, | |
275 | .close = uhid_hid_close, | |
276 | .hidinput_input_event = uhid_hid_input, | |
277 | .parse = uhid_hid_parse, | |
278 | }; | |
279 | ||
befde022 DT |
280 | #ifdef CONFIG_COMPAT |
281 | ||
282 | /* Apparently we haven't stepped on these rakes enough times yet. */ | |
283 | struct uhid_create_req_compat { | |
284 | __u8 name[128]; | |
285 | __u8 phys[64]; | |
286 | __u8 uniq[64]; | |
287 | ||
288 | compat_uptr_t rd_data; | |
289 | __u16 rd_size; | |
290 | ||
291 | __u16 bus; | |
292 | __u32 vendor; | |
293 | __u32 product; | |
294 | __u32 version; | |
295 | __u32 country; | |
296 | } __attribute__((__packed__)); | |
297 | ||
298 | static int uhid_event_from_user(const char __user *buffer, size_t len, | |
299 | struct uhid_event *event) | |
300 | { | |
301 | if (is_compat_task()) { | |
302 | u32 type; | |
303 | ||
304 | if (get_user(type, buffer)) | |
305 | return -EFAULT; | |
306 | ||
307 | if (type == UHID_CREATE) { | |
308 | /* | |
309 | * This is our messed up request with compat pointer. | |
310 | * It is largish (more than 256 bytes) so we better | |
311 | * allocate it from the heap. | |
312 | */ | |
313 | struct uhid_create_req_compat *compat; | |
314 | ||
315 | compat = kmalloc(sizeof(*compat), GFP_KERNEL); | |
316 | if (!compat) | |
317 | return -ENOMEM; | |
318 | ||
319 | buffer += sizeof(type); | |
320 | len -= sizeof(type); | |
321 | if (copy_from_user(compat, buffer, | |
322 | min(len, sizeof(*compat)))) { | |
323 | kfree(compat); | |
324 | return -EFAULT; | |
325 | } | |
326 | ||
327 | /* Shuffle the data over to proper structure */ | |
328 | event->type = type; | |
329 | ||
330 | memcpy(event->u.create.name, compat->name, | |
331 | sizeof(compat->name)); | |
332 | memcpy(event->u.create.phys, compat->phys, | |
333 | sizeof(compat->phys)); | |
334 | memcpy(event->u.create.uniq, compat->uniq, | |
335 | sizeof(compat->uniq)); | |
336 | ||
337 | event->u.create.rd_data = compat_ptr(compat->rd_data); | |
338 | event->u.create.rd_size = compat->rd_size; | |
339 | ||
340 | event->u.create.bus = compat->bus; | |
341 | event->u.create.vendor = compat->vendor; | |
342 | event->u.create.product = compat->product; | |
343 | event->u.create.version = compat->version; | |
344 | event->u.create.country = compat->country; | |
345 | ||
346 | kfree(compat); | |
347 | return 0; | |
348 | } | |
349 | /* All others can be copied directly */ | |
350 | } | |
351 | ||
352 | if (copy_from_user(event, buffer, min(len, sizeof(*event)))) | |
353 | return -EFAULT; | |
354 | ||
355 | return 0; | |
356 | } | |
357 | #else | |
358 | static int uhid_event_from_user(const char __user *buffer, size_t len, | |
359 | struct uhid_event *event) | |
360 | { | |
361 | if (copy_from_user(event, buffer, min(len, sizeof(*event)))) | |
362 | return -EFAULT; | |
363 | ||
364 | return 0; | |
365 | } | |
366 | #endif | |
367 | ||
d365c6cf DH |
368 | static int uhid_dev_create(struct uhid_device *uhid, |
369 | const struct uhid_event *ev) | |
370 | { | |
371 | struct hid_device *hid; | |
372 | int ret; | |
373 | ||
374 | if (uhid->running) | |
375 | return -EALREADY; | |
376 | ||
377 | uhid->rd_size = ev->u.create.rd_size; | |
378 | if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE) | |
379 | return -EINVAL; | |
380 | ||
381 | uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL); | |
382 | if (!uhid->rd_data) | |
383 | return -ENOMEM; | |
384 | ||
385 | if (copy_from_user(uhid->rd_data, ev->u.create.rd_data, | |
386 | uhid->rd_size)) { | |
387 | ret = -EFAULT; | |
388 | goto err_free; | |
389 | } | |
390 | ||
391 | hid = hid_allocate_device(); | |
392 | if (IS_ERR(hid)) { | |
393 | ret = PTR_ERR(hid); | |
394 | goto err_free; | |
395 | } | |
396 | ||
397 | strncpy(hid->name, ev->u.create.name, 127); | |
398 | hid->name[127] = 0; | |
399 | strncpy(hid->phys, ev->u.create.phys, 63); | |
400 | hid->phys[63] = 0; | |
401 | strncpy(hid->uniq, ev->u.create.uniq, 63); | |
402 | hid->uniq[63] = 0; | |
403 | ||
404 | hid->ll_driver = &uhid_hid_driver; | |
405 | hid->hid_get_raw_report = uhid_hid_get_raw; | |
406 | hid->hid_output_raw_report = uhid_hid_output_raw; | |
407 | hid->bus = ev->u.create.bus; | |
408 | hid->vendor = ev->u.create.vendor; | |
409 | hid->product = ev->u.create.product; | |
410 | hid->version = ev->u.create.version; | |
411 | hid->country = ev->u.create.country; | |
412 | hid->driver_data = uhid; | |
413 | hid->dev.parent = uhid_misc.this_device; | |
414 | ||
415 | uhid->hid = hid; | |
416 | uhid->running = true; | |
417 | ||
418 | ret = hid_add_device(hid); | |
419 | if (ret) { | |
420 | hid_err(hid, "Cannot register HID device\n"); | |
421 | goto err_hid; | |
422 | } | |
423 | ||
424 | return 0; | |
425 | ||
426 | err_hid: | |
427 | hid_destroy_device(hid); | |
428 | uhid->hid = NULL; | |
429 | uhid->running = false; | |
430 | err_free: | |
431 | kfree(uhid->rd_data); | |
432 | return ret; | |
433 | } | |
434 | ||
435 | static int uhid_dev_destroy(struct uhid_device *uhid) | |
436 | { | |
437 | if (!uhid->running) | |
438 | return -EINVAL; | |
439 | ||
fcfcf0de | 440 | /* clear "running" before setting "report_done" */ |
d365c6cf | 441 | uhid->running = false; |
fcfcf0de DH |
442 | smp_wmb(); |
443 | atomic_set(&uhid->report_done, 1); | |
444 | wake_up_interruptible(&uhid->report_wait); | |
d365c6cf DH |
445 | |
446 | hid_destroy_device(uhid->hid); | |
447 | kfree(uhid->rd_data); | |
448 | ||
449 | return 0; | |
450 | } | |
451 | ||
5e87a36a DH |
452 | static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev) |
453 | { | |
454 | if (!uhid->running) | |
455 | return -EINVAL; | |
456 | ||
457 | hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data, | |
458 | min_t(size_t, ev->u.input.size, UHID_DATA_MAX), 0); | |
459 | ||
460 | return 0; | |
461 | } | |
462 | ||
fcfcf0de DH |
463 | static int uhid_dev_feature_answer(struct uhid_device *uhid, |
464 | struct uhid_event *ev) | |
465 | { | |
466 | unsigned long flags; | |
467 | ||
468 | if (!uhid->running) | |
469 | return -EINVAL; | |
470 | ||
471 | spin_lock_irqsave(&uhid->qlock, flags); | |
472 | ||
473 | /* id for old report; drop it silently */ | |
474 | if (atomic_read(&uhid->report_id) != ev->u.feature_answer.id) | |
475 | goto unlock; | |
476 | if (atomic_read(&uhid->report_done)) | |
477 | goto unlock; | |
478 | ||
479 | memcpy(&uhid->report_buf, ev, sizeof(*ev)); | |
480 | atomic_set(&uhid->report_done, 1); | |
481 | wake_up_interruptible(&uhid->report_wait); | |
482 | ||
483 | unlock: | |
484 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
485 | return 0; | |
486 | } | |
487 | ||
1ccd7a2a DH |
488 | static int uhid_char_open(struct inode *inode, struct file *file) |
489 | { | |
ace3d861 DH |
490 | struct uhid_device *uhid; |
491 | ||
492 | uhid = kzalloc(sizeof(*uhid), GFP_KERNEL); | |
493 | if (!uhid) | |
494 | return -ENOMEM; | |
495 | ||
d937ae5f | 496 | mutex_init(&uhid->devlock); |
fcfcf0de | 497 | mutex_init(&uhid->report_lock); |
ace3d861 DH |
498 | spin_lock_init(&uhid->qlock); |
499 | init_waitqueue_head(&uhid->waitq); | |
fcfcf0de | 500 | init_waitqueue_head(&uhid->report_wait); |
d365c6cf | 501 | uhid->running = false; |
fcfcf0de | 502 | atomic_set(&uhid->report_done, 1); |
ace3d861 DH |
503 | |
504 | file->private_data = uhid; | |
505 | nonseekable_open(inode, file); | |
506 | ||
1ccd7a2a DH |
507 | return 0; |
508 | } | |
509 | ||
510 | static int uhid_char_release(struct inode *inode, struct file *file) | |
511 | { | |
ace3d861 DH |
512 | struct uhid_device *uhid = file->private_data; |
513 | unsigned int i; | |
514 | ||
d365c6cf DH |
515 | uhid_dev_destroy(uhid); |
516 | ||
ace3d861 DH |
517 | for (i = 0; i < UHID_BUFSIZE; ++i) |
518 | kfree(uhid->outq[i]); | |
519 | ||
520 | kfree(uhid); | |
521 | ||
1ccd7a2a DH |
522 | return 0; |
523 | } | |
524 | ||
525 | static ssize_t uhid_char_read(struct file *file, char __user *buffer, | |
526 | size_t count, loff_t *ppos) | |
527 | { | |
d937ae5f DH |
528 | struct uhid_device *uhid = file->private_data; |
529 | int ret; | |
530 | unsigned long flags; | |
531 | size_t len; | |
532 | ||
533 | /* they need at least the "type" member of uhid_event */ | |
534 | if (count < sizeof(__u32)) | |
535 | return -EINVAL; | |
536 | ||
537 | try_again: | |
538 | if (file->f_flags & O_NONBLOCK) { | |
539 | if (uhid->head == uhid->tail) | |
540 | return -EAGAIN; | |
541 | } else { | |
542 | ret = wait_event_interruptible(uhid->waitq, | |
543 | uhid->head != uhid->tail); | |
544 | if (ret) | |
545 | return ret; | |
546 | } | |
547 | ||
548 | ret = mutex_lock_interruptible(&uhid->devlock); | |
549 | if (ret) | |
550 | return ret; | |
551 | ||
552 | if (uhid->head == uhid->tail) { | |
553 | mutex_unlock(&uhid->devlock); | |
554 | goto try_again; | |
555 | } else { | |
556 | len = min(count, sizeof(**uhid->outq)); | |
adefb69b | 557 | if (copy_to_user(buffer, uhid->outq[uhid->tail], len)) { |
d937ae5f DH |
558 | ret = -EFAULT; |
559 | } else { | |
560 | kfree(uhid->outq[uhid->tail]); | |
561 | uhid->outq[uhid->tail] = NULL; | |
562 | ||
563 | spin_lock_irqsave(&uhid->qlock, flags); | |
564 | uhid->tail = (uhid->tail + 1) % UHID_BUFSIZE; | |
565 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
566 | } | |
567 | } | |
568 | ||
569 | mutex_unlock(&uhid->devlock); | |
570 | return ret ? ret : len; | |
1ccd7a2a DH |
571 | } |
572 | ||
573 | static ssize_t uhid_char_write(struct file *file, const char __user *buffer, | |
574 | size_t count, loff_t *ppos) | |
575 | { | |
6664ef72 DH |
576 | struct uhid_device *uhid = file->private_data; |
577 | int ret; | |
578 | size_t len; | |
579 | ||
580 | /* we need at least the "type" member of uhid_event */ | |
581 | if (count < sizeof(__u32)) | |
582 | return -EINVAL; | |
583 | ||
584 | ret = mutex_lock_interruptible(&uhid->devlock); | |
585 | if (ret) | |
586 | return ret; | |
587 | ||
588 | memset(&uhid->input_buf, 0, sizeof(uhid->input_buf)); | |
589 | len = min(count, sizeof(uhid->input_buf)); | |
befde022 DT |
590 | |
591 | ret = uhid_event_from_user(buffer, len, &uhid->input_buf); | |
592 | if (ret) | |
6664ef72 | 593 | goto unlock; |
6664ef72 DH |
594 | |
595 | switch (uhid->input_buf.type) { | |
d365c6cf DH |
596 | case UHID_CREATE: |
597 | ret = uhid_dev_create(uhid, &uhid->input_buf); | |
598 | break; | |
599 | case UHID_DESTROY: | |
600 | ret = uhid_dev_destroy(uhid); | |
601 | break; | |
5e87a36a DH |
602 | case UHID_INPUT: |
603 | ret = uhid_dev_input(uhid, &uhid->input_buf); | |
604 | break; | |
fcfcf0de DH |
605 | case UHID_FEATURE_ANSWER: |
606 | ret = uhid_dev_feature_answer(uhid, &uhid->input_buf); | |
607 | break; | |
6664ef72 DH |
608 | default: |
609 | ret = -EOPNOTSUPP; | |
610 | } | |
611 | ||
612 | unlock: | |
613 | mutex_unlock(&uhid->devlock); | |
614 | ||
615 | /* return "count" not "len" to not confuse the caller */ | |
616 | return ret ? ret : count; | |
1ccd7a2a DH |
617 | } |
618 | ||
619 | static unsigned int uhid_char_poll(struct file *file, poll_table *wait) | |
620 | { | |
1f9dec1e DH |
621 | struct uhid_device *uhid = file->private_data; |
622 | ||
623 | poll_wait(file, &uhid->waitq, wait); | |
624 | ||
625 | if (uhid->head != uhid->tail) | |
626 | return POLLIN | POLLRDNORM; | |
627 | ||
1ccd7a2a DH |
628 | return 0; |
629 | } | |
630 | ||
631 | static const struct file_operations uhid_fops = { | |
632 | .owner = THIS_MODULE, | |
633 | .open = uhid_char_open, | |
634 | .release = uhid_char_release, | |
635 | .read = uhid_char_read, | |
636 | .write = uhid_char_write, | |
637 | .poll = uhid_char_poll, | |
638 | .llseek = no_llseek, | |
639 | }; | |
640 | ||
641 | static struct miscdevice uhid_misc = { | |
642 | .fops = &uhid_fops, | |
643 | .minor = MISC_DYNAMIC_MINOR, | |
644 | .name = UHID_NAME, | |
645 | }; | |
646 | ||
647 | static int __init uhid_init(void) | |
648 | { | |
649 | return misc_register(&uhid_misc); | |
650 | } | |
651 | ||
652 | static void __exit uhid_exit(void) | |
653 | { | |
654 | misc_deregister(&uhid_misc); | |
655 | } | |
656 | ||
657 | module_init(uhid_init); | |
658 | module_exit(uhid_exit); | |
659 | MODULE_LICENSE("GPL"); | |
660 | MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>"); | |
661 | MODULE_DESCRIPTION("User-space I/O driver support for HID subsystem"); |