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 | ||
d365c6cf DH |
119 | static int uhid_hid_parse(struct hid_device *hid) |
120 | { | |
037c061b DH |
121 | struct uhid_device *uhid = hid->driver_data; |
122 | ||
123 | return hid_parse_report(hid, uhid->rd_data, uhid->rd_size); | |
d365c6cf DH |
124 | } |
125 | ||
289a7162 JK |
126 | static int uhid_hid_get_raw(struct hid_device *hid, unsigned char rnum, |
127 | __u8 *buf, size_t count, unsigned char rtype) | |
128 | { | |
129 | struct uhid_device *uhid = hid->driver_data; | |
130 | __u8 report_type; | |
131 | struct uhid_event *ev; | |
132 | unsigned long flags; | |
133 | int ret; | |
134 | size_t uninitialized_var(len); | |
135 | struct uhid_feature_answer_req *req; | |
136 | ||
137 | if (!uhid->running) | |
138 | return -EIO; | |
139 | ||
140 | switch (rtype) { | |
141 | case HID_FEATURE_REPORT: | |
142 | report_type = UHID_FEATURE_REPORT; | |
143 | break; | |
144 | case HID_OUTPUT_REPORT: | |
145 | report_type = UHID_OUTPUT_REPORT; | |
146 | break; | |
147 | case HID_INPUT_REPORT: | |
148 | report_type = UHID_INPUT_REPORT; | |
149 | break; | |
150 | default: | |
151 | return -EINVAL; | |
152 | } | |
153 | ||
154 | ret = mutex_lock_interruptible(&uhid->report_lock); | |
155 | if (ret) | |
156 | return ret; | |
157 | ||
158 | ev = kzalloc(sizeof(*ev), GFP_KERNEL); | |
159 | if (!ev) { | |
160 | ret = -ENOMEM; | |
161 | goto unlock; | |
162 | } | |
163 | ||
164 | spin_lock_irqsave(&uhid->qlock, flags); | |
165 | ev->type = UHID_FEATURE; | |
166 | ev->u.feature.id = atomic_inc_return(&uhid->report_id); | |
167 | ev->u.feature.rnum = rnum; | |
168 | ev->u.feature.rtype = report_type; | |
169 | ||
170 | atomic_set(&uhid->report_done, 0); | |
171 | uhid_queue(uhid, ev); | |
172 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
173 | ||
174 | ret = wait_event_interruptible_timeout(uhid->report_wait, | |
175 | atomic_read(&uhid->report_done), 5 * HZ); | |
176 | ||
177 | /* | |
178 | * Make sure "uhid->running" is cleared on shutdown before | |
179 | * "uhid->report_done" is set. | |
180 | */ | |
181 | smp_rmb(); | |
182 | if (!ret || !uhid->running) { | |
183 | ret = -EIO; | |
184 | } else if (ret < 0) { | |
185 | ret = -ERESTARTSYS; | |
186 | } else { | |
187 | spin_lock_irqsave(&uhid->qlock, flags); | |
188 | req = &uhid->report_buf.u.feature_answer; | |
189 | ||
190 | if (req->err) { | |
191 | ret = -EIO; | |
192 | } else { | |
193 | ret = 0; | |
194 | len = min(count, | |
195 | min_t(size_t, req->size, UHID_DATA_MAX)); | |
196 | memcpy(buf, req->data, len); | |
197 | } | |
198 | ||
199 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
200 | } | |
201 | ||
202 | atomic_set(&uhid->report_done, 1); | |
203 | ||
204 | unlock: | |
205 | mutex_unlock(&uhid->report_lock); | |
206 | return ret ? ret : len; | |
207 | } | |
208 | ||
d365c6cf DH |
209 | static int uhid_hid_output_raw(struct hid_device *hid, __u8 *buf, size_t count, |
210 | unsigned char report_type) | |
211 | { | |
3b3baa82 DH |
212 | struct uhid_device *uhid = hid->driver_data; |
213 | __u8 rtype; | |
214 | unsigned long flags; | |
215 | struct uhid_event *ev; | |
216 | ||
217 | switch (report_type) { | |
218 | case HID_FEATURE_REPORT: | |
219 | rtype = UHID_FEATURE_REPORT; | |
220 | break; | |
221 | case HID_OUTPUT_REPORT: | |
222 | rtype = UHID_OUTPUT_REPORT; | |
223 | break; | |
224 | default: | |
225 | return -EINVAL; | |
226 | } | |
227 | ||
228 | if (count < 1 || count > UHID_DATA_MAX) | |
229 | return -EINVAL; | |
230 | ||
231 | ev = kzalloc(sizeof(*ev), GFP_KERNEL); | |
232 | if (!ev) | |
233 | return -ENOMEM; | |
234 | ||
235 | ev->type = UHID_OUTPUT; | |
236 | ev->u.output.size = count; | |
237 | ev->u.output.rtype = rtype; | |
238 | memcpy(ev->u.output.data, buf, count); | |
239 | ||
240 | spin_lock_irqsave(&uhid->qlock, flags); | |
241 | uhid_queue(uhid, ev); | |
242 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
243 | ||
244 | return count; | |
d365c6cf DH |
245 | } |
246 | ||
596cfdd8 FP |
247 | static int uhid_hid_output_report(struct hid_device *hid, __u8 *buf, |
248 | size_t count) | |
249 | { | |
41abfb36 | 250 | return uhid_hid_output_raw(hid, buf, count, HID_OUTPUT_REPORT); |
596cfdd8 FP |
251 | } |
252 | ||
706daeff BT |
253 | static int uhid_raw_request(struct hid_device *hid, unsigned char reportnum, |
254 | __u8 *buf, size_t len, unsigned char rtype, | |
255 | int reqtype) | |
256 | { | |
257 | switch (reqtype) { | |
258 | case HID_REQ_GET_REPORT: | |
259 | return uhid_hid_get_raw(hid, reportnum, buf, len, rtype); | |
260 | case HID_REQ_SET_REPORT: | |
261 | /* TODO: implement proper SET_REPORT functionality */ | |
262 | return -ENOSYS; | |
263 | default: | |
264 | return -EIO; | |
265 | } | |
266 | } | |
267 | ||
d365c6cf DH |
268 | static struct hid_ll_driver uhid_hid_driver = { |
269 | .start = uhid_hid_start, | |
270 | .stop = uhid_hid_stop, | |
271 | .open = uhid_hid_open, | |
272 | .close = uhid_hid_close, | |
d365c6cf | 273 | .parse = uhid_hid_parse, |
596cfdd8 | 274 | .output_report = uhid_hid_output_report, |
706daeff | 275 | .raw_request = uhid_raw_request, |
d365c6cf DH |
276 | }; |
277 | ||
befde022 DT |
278 | #ifdef CONFIG_COMPAT |
279 | ||
280 | /* Apparently we haven't stepped on these rakes enough times yet. */ | |
281 | struct uhid_create_req_compat { | |
282 | __u8 name[128]; | |
283 | __u8 phys[64]; | |
284 | __u8 uniq[64]; | |
285 | ||
286 | compat_uptr_t rd_data; | |
287 | __u16 rd_size; | |
288 | ||
289 | __u16 bus; | |
290 | __u32 vendor; | |
291 | __u32 product; | |
292 | __u32 version; | |
293 | __u32 country; | |
294 | } __attribute__((__packed__)); | |
295 | ||
296 | static int uhid_event_from_user(const char __user *buffer, size_t len, | |
297 | struct uhid_event *event) | |
298 | { | |
299 | if (is_compat_task()) { | |
300 | u32 type; | |
301 | ||
302 | if (get_user(type, buffer)) | |
303 | return -EFAULT; | |
304 | ||
305 | if (type == UHID_CREATE) { | |
306 | /* | |
307 | * This is our messed up request with compat pointer. | |
308 | * It is largish (more than 256 bytes) so we better | |
309 | * allocate it from the heap. | |
310 | */ | |
311 | struct uhid_create_req_compat *compat; | |
312 | ||
80897aa7 | 313 | compat = kzalloc(sizeof(*compat), GFP_KERNEL); |
befde022 DT |
314 | if (!compat) |
315 | return -ENOMEM; | |
316 | ||
317 | buffer += sizeof(type); | |
318 | len -= sizeof(type); | |
319 | if (copy_from_user(compat, buffer, | |
320 | min(len, sizeof(*compat)))) { | |
321 | kfree(compat); | |
322 | return -EFAULT; | |
323 | } | |
324 | ||
325 | /* Shuffle the data over to proper structure */ | |
326 | event->type = type; | |
327 | ||
328 | memcpy(event->u.create.name, compat->name, | |
329 | sizeof(compat->name)); | |
330 | memcpy(event->u.create.phys, compat->phys, | |
331 | sizeof(compat->phys)); | |
332 | memcpy(event->u.create.uniq, compat->uniq, | |
333 | sizeof(compat->uniq)); | |
334 | ||
335 | event->u.create.rd_data = compat_ptr(compat->rd_data); | |
336 | event->u.create.rd_size = compat->rd_size; | |
337 | ||
338 | event->u.create.bus = compat->bus; | |
339 | event->u.create.vendor = compat->vendor; | |
340 | event->u.create.product = compat->product; | |
341 | event->u.create.version = compat->version; | |
342 | event->u.create.country = compat->country; | |
343 | ||
344 | kfree(compat); | |
345 | return 0; | |
346 | } | |
347 | /* All others can be copied directly */ | |
348 | } | |
349 | ||
350 | if (copy_from_user(event, buffer, min(len, sizeof(*event)))) | |
351 | return -EFAULT; | |
352 | ||
353 | return 0; | |
354 | } | |
355 | #else | |
356 | static int uhid_event_from_user(const char __user *buffer, size_t len, | |
357 | struct uhid_event *event) | |
358 | { | |
359 | if (copy_from_user(event, buffer, min(len, sizeof(*event)))) | |
360 | return -EFAULT; | |
361 | ||
362 | return 0; | |
363 | } | |
364 | #endif | |
365 | ||
d365c6cf DH |
366 | static int uhid_dev_create(struct uhid_device *uhid, |
367 | const struct uhid_event *ev) | |
368 | { | |
369 | struct hid_device *hid; | |
370 | int ret; | |
371 | ||
372 | if (uhid->running) | |
373 | return -EALREADY; | |
374 | ||
375 | uhid->rd_size = ev->u.create.rd_size; | |
376 | if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE) | |
377 | return -EINVAL; | |
378 | ||
379 | uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL); | |
380 | if (!uhid->rd_data) | |
381 | return -ENOMEM; | |
382 | ||
383 | if (copy_from_user(uhid->rd_data, ev->u.create.rd_data, | |
384 | uhid->rd_size)) { | |
385 | ret = -EFAULT; | |
386 | goto err_free; | |
387 | } | |
388 | ||
389 | hid = hid_allocate_device(); | |
390 | if (IS_ERR(hid)) { | |
391 | ret = PTR_ERR(hid); | |
392 | goto err_free; | |
393 | } | |
394 | ||
395 | strncpy(hid->name, ev->u.create.name, 127); | |
396 | hid->name[127] = 0; | |
397 | strncpy(hid->phys, ev->u.create.phys, 63); | |
398 | hid->phys[63] = 0; | |
399 | strncpy(hid->uniq, ev->u.create.uniq, 63); | |
400 | hid->uniq[63] = 0; | |
401 | ||
402 | hid->ll_driver = &uhid_hid_driver; | |
d365c6cf DH |
403 | hid->bus = ev->u.create.bus; |
404 | hid->vendor = ev->u.create.vendor; | |
405 | hid->product = ev->u.create.product; | |
406 | hid->version = ev->u.create.version; | |
407 | hid->country = ev->u.create.country; | |
408 | hid->driver_data = uhid; | |
409 | hid->dev.parent = uhid_misc.this_device; | |
410 | ||
411 | uhid->hid = hid; | |
412 | uhid->running = true; | |
413 | ||
414 | ret = hid_add_device(hid); | |
415 | if (ret) { | |
416 | hid_err(hid, "Cannot register HID device\n"); | |
417 | goto err_hid; | |
418 | } | |
419 | ||
420 | return 0; | |
421 | ||
422 | err_hid: | |
423 | hid_destroy_device(hid); | |
424 | uhid->hid = NULL; | |
425 | uhid->running = false; | |
426 | err_free: | |
427 | kfree(uhid->rd_data); | |
428 | return ret; | |
429 | } | |
430 | ||
4522643a PG |
431 | static int uhid_dev_create2(struct uhid_device *uhid, |
432 | const struct uhid_event *ev) | |
433 | { | |
434 | struct hid_device *hid; | |
435 | int ret; | |
436 | ||
437 | if (uhid->running) | |
438 | return -EALREADY; | |
439 | ||
440 | uhid->rd_size = ev->u.create2.rd_size; | |
441 | if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE) | |
442 | return -EINVAL; | |
443 | ||
444 | uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL); | |
445 | if (!uhid->rd_data) | |
446 | return -ENOMEM; | |
447 | ||
448 | memcpy(uhid->rd_data, ev->u.create2.rd_data, uhid->rd_size); | |
449 | ||
450 | hid = hid_allocate_device(); | |
451 | if (IS_ERR(hid)) { | |
452 | ret = PTR_ERR(hid); | |
453 | goto err_free; | |
454 | } | |
455 | ||
456 | strncpy(hid->name, ev->u.create2.name, 127); | |
457 | hid->name[127] = 0; | |
458 | strncpy(hid->phys, ev->u.create2.phys, 63); | |
459 | hid->phys[63] = 0; | |
460 | strncpy(hid->uniq, ev->u.create2.uniq, 63); | |
461 | hid->uniq[63] = 0; | |
462 | ||
463 | hid->ll_driver = &uhid_hid_driver; | |
464 | hid->bus = ev->u.create2.bus; | |
465 | hid->vendor = ev->u.create2.vendor; | |
466 | hid->product = ev->u.create2.product; | |
467 | hid->version = ev->u.create2.version; | |
468 | hid->country = ev->u.create2.country; | |
469 | hid->driver_data = uhid; | |
470 | hid->dev.parent = uhid_misc.this_device; | |
471 | ||
472 | uhid->hid = hid; | |
473 | uhid->running = true; | |
474 | ||
475 | ret = hid_add_device(hid); | |
476 | if (ret) { | |
477 | hid_err(hid, "Cannot register HID device\n"); | |
478 | goto err_hid; | |
479 | } | |
480 | ||
481 | return 0; | |
482 | ||
483 | err_hid: | |
484 | hid_destroy_device(hid); | |
485 | uhid->hid = NULL; | |
486 | uhid->running = false; | |
487 | err_free: | |
488 | kfree(uhid->rd_data); | |
489 | return ret; | |
490 | } | |
491 | ||
d365c6cf DH |
492 | static int uhid_dev_destroy(struct uhid_device *uhid) |
493 | { | |
494 | if (!uhid->running) | |
495 | return -EINVAL; | |
496 | ||
fcfcf0de | 497 | /* clear "running" before setting "report_done" */ |
d365c6cf | 498 | uhid->running = false; |
fcfcf0de DH |
499 | smp_wmb(); |
500 | atomic_set(&uhid->report_done, 1); | |
501 | wake_up_interruptible(&uhid->report_wait); | |
d365c6cf DH |
502 | |
503 | hid_destroy_device(uhid->hid); | |
504 | kfree(uhid->rd_data); | |
505 | ||
506 | return 0; | |
507 | } | |
508 | ||
5e87a36a DH |
509 | static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev) |
510 | { | |
511 | if (!uhid->running) | |
512 | return -EINVAL; | |
513 | ||
514 | hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data, | |
515 | min_t(size_t, ev->u.input.size, UHID_DATA_MAX), 0); | |
516 | ||
517 | return 0; | |
518 | } | |
519 | ||
4522643a PG |
520 | static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev) |
521 | { | |
522 | if (!uhid->running) | |
523 | return -EINVAL; | |
524 | ||
525 | hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data, | |
526 | min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0); | |
527 | ||
528 | return 0; | |
529 | } | |
530 | ||
fcfcf0de DH |
531 | static int uhid_dev_feature_answer(struct uhid_device *uhid, |
532 | struct uhid_event *ev) | |
533 | { | |
534 | unsigned long flags; | |
535 | ||
536 | if (!uhid->running) | |
537 | return -EINVAL; | |
538 | ||
539 | spin_lock_irqsave(&uhid->qlock, flags); | |
540 | ||
541 | /* id for old report; drop it silently */ | |
542 | if (atomic_read(&uhid->report_id) != ev->u.feature_answer.id) | |
543 | goto unlock; | |
544 | if (atomic_read(&uhid->report_done)) | |
545 | goto unlock; | |
546 | ||
547 | memcpy(&uhid->report_buf, ev, sizeof(*ev)); | |
548 | atomic_set(&uhid->report_done, 1); | |
549 | wake_up_interruptible(&uhid->report_wait); | |
550 | ||
551 | unlock: | |
552 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
553 | return 0; | |
554 | } | |
555 | ||
1ccd7a2a DH |
556 | static int uhid_char_open(struct inode *inode, struct file *file) |
557 | { | |
ace3d861 DH |
558 | struct uhid_device *uhid; |
559 | ||
560 | uhid = kzalloc(sizeof(*uhid), GFP_KERNEL); | |
561 | if (!uhid) | |
562 | return -ENOMEM; | |
563 | ||
d937ae5f | 564 | mutex_init(&uhid->devlock); |
fcfcf0de | 565 | mutex_init(&uhid->report_lock); |
ace3d861 DH |
566 | spin_lock_init(&uhid->qlock); |
567 | init_waitqueue_head(&uhid->waitq); | |
fcfcf0de | 568 | init_waitqueue_head(&uhid->report_wait); |
d365c6cf | 569 | uhid->running = false; |
fcfcf0de | 570 | atomic_set(&uhid->report_done, 1); |
ace3d861 DH |
571 | |
572 | file->private_data = uhid; | |
573 | nonseekable_open(inode, file); | |
574 | ||
1ccd7a2a DH |
575 | return 0; |
576 | } | |
577 | ||
578 | static int uhid_char_release(struct inode *inode, struct file *file) | |
579 | { | |
ace3d861 DH |
580 | struct uhid_device *uhid = file->private_data; |
581 | unsigned int i; | |
582 | ||
d365c6cf DH |
583 | uhid_dev_destroy(uhid); |
584 | ||
ace3d861 DH |
585 | for (i = 0; i < UHID_BUFSIZE; ++i) |
586 | kfree(uhid->outq[i]); | |
587 | ||
588 | kfree(uhid); | |
589 | ||
1ccd7a2a DH |
590 | return 0; |
591 | } | |
592 | ||
593 | static ssize_t uhid_char_read(struct file *file, char __user *buffer, | |
594 | size_t count, loff_t *ppos) | |
595 | { | |
d937ae5f DH |
596 | struct uhid_device *uhid = file->private_data; |
597 | int ret; | |
598 | unsigned long flags; | |
599 | size_t len; | |
600 | ||
601 | /* they need at least the "type" member of uhid_event */ | |
602 | if (count < sizeof(__u32)) | |
603 | return -EINVAL; | |
604 | ||
605 | try_again: | |
606 | if (file->f_flags & O_NONBLOCK) { | |
607 | if (uhid->head == uhid->tail) | |
608 | return -EAGAIN; | |
609 | } else { | |
610 | ret = wait_event_interruptible(uhid->waitq, | |
611 | uhid->head != uhid->tail); | |
612 | if (ret) | |
613 | return ret; | |
614 | } | |
615 | ||
616 | ret = mutex_lock_interruptible(&uhid->devlock); | |
617 | if (ret) | |
618 | return ret; | |
619 | ||
620 | if (uhid->head == uhid->tail) { | |
621 | mutex_unlock(&uhid->devlock); | |
622 | goto try_again; | |
623 | } else { | |
624 | len = min(count, sizeof(**uhid->outq)); | |
adefb69b | 625 | if (copy_to_user(buffer, uhid->outq[uhid->tail], len)) { |
d937ae5f DH |
626 | ret = -EFAULT; |
627 | } else { | |
628 | kfree(uhid->outq[uhid->tail]); | |
629 | uhid->outq[uhid->tail] = NULL; | |
630 | ||
631 | spin_lock_irqsave(&uhid->qlock, flags); | |
632 | uhid->tail = (uhid->tail + 1) % UHID_BUFSIZE; | |
633 | spin_unlock_irqrestore(&uhid->qlock, flags); | |
634 | } | |
635 | } | |
636 | ||
637 | mutex_unlock(&uhid->devlock); | |
638 | return ret ? ret : len; | |
1ccd7a2a DH |
639 | } |
640 | ||
641 | static ssize_t uhid_char_write(struct file *file, const char __user *buffer, | |
642 | size_t count, loff_t *ppos) | |
643 | { | |
6664ef72 DH |
644 | struct uhid_device *uhid = file->private_data; |
645 | int ret; | |
646 | size_t len; | |
647 | ||
648 | /* we need at least the "type" member of uhid_event */ | |
649 | if (count < sizeof(__u32)) | |
650 | return -EINVAL; | |
651 | ||
652 | ret = mutex_lock_interruptible(&uhid->devlock); | |
653 | if (ret) | |
654 | return ret; | |
655 | ||
656 | memset(&uhid->input_buf, 0, sizeof(uhid->input_buf)); | |
657 | len = min(count, sizeof(uhid->input_buf)); | |
befde022 DT |
658 | |
659 | ret = uhid_event_from_user(buffer, len, &uhid->input_buf); | |
660 | if (ret) | |
6664ef72 | 661 | goto unlock; |
6664ef72 DH |
662 | |
663 | switch (uhid->input_buf.type) { | |
d365c6cf DH |
664 | case UHID_CREATE: |
665 | ret = uhid_dev_create(uhid, &uhid->input_buf); | |
666 | break; | |
4522643a PG |
667 | case UHID_CREATE2: |
668 | ret = uhid_dev_create2(uhid, &uhid->input_buf); | |
669 | break; | |
d365c6cf DH |
670 | case UHID_DESTROY: |
671 | ret = uhid_dev_destroy(uhid); | |
672 | break; | |
5e87a36a DH |
673 | case UHID_INPUT: |
674 | ret = uhid_dev_input(uhid, &uhid->input_buf); | |
675 | break; | |
4522643a PG |
676 | case UHID_INPUT2: |
677 | ret = uhid_dev_input2(uhid, &uhid->input_buf); | |
678 | break; | |
fcfcf0de DH |
679 | case UHID_FEATURE_ANSWER: |
680 | ret = uhid_dev_feature_answer(uhid, &uhid->input_buf); | |
681 | break; | |
6664ef72 DH |
682 | default: |
683 | ret = -EOPNOTSUPP; | |
684 | } | |
685 | ||
686 | unlock: | |
687 | mutex_unlock(&uhid->devlock); | |
688 | ||
689 | /* return "count" not "len" to not confuse the caller */ | |
690 | return ret ? ret : count; | |
1ccd7a2a DH |
691 | } |
692 | ||
693 | static unsigned int uhid_char_poll(struct file *file, poll_table *wait) | |
694 | { | |
1f9dec1e DH |
695 | struct uhid_device *uhid = file->private_data; |
696 | ||
697 | poll_wait(file, &uhid->waitq, wait); | |
698 | ||
699 | if (uhid->head != uhid->tail) | |
700 | return POLLIN | POLLRDNORM; | |
701 | ||
1ccd7a2a DH |
702 | return 0; |
703 | } | |
704 | ||
705 | static const struct file_operations uhid_fops = { | |
706 | .owner = THIS_MODULE, | |
707 | .open = uhid_char_open, | |
708 | .release = uhid_char_release, | |
709 | .read = uhid_char_read, | |
710 | .write = uhid_char_write, | |
711 | .poll = uhid_char_poll, | |
712 | .llseek = no_llseek, | |
713 | }; | |
714 | ||
715 | static struct miscdevice uhid_misc = { | |
716 | .fops = &uhid_fops, | |
19872d20 | 717 | .minor = UHID_MINOR, |
1ccd7a2a DH |
718 | .name = UHID_NAME, |
719 | }; | |
720 | ||
721 | static int __init uhid_init(void) | |
722 | { | |
723 | return misc_register(&uhid_misc); | |
724 | } | |
725 | ||
726 | static void __exit uhid_exit(void) | |
727 | { | |
728 | misc_deregister(&uhid_misc); | |
729 | } | |
730 | ||
731 | module_init(uhid_init); | |
732 | module_exit(uhid_exit); | |
733 | MODULE_LICENSE("GPL"); | |
734 | MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>"); | |
735 | MODULE_DESCRIPTION("User-space I/O driver support for HID subsystem"); | |
19872d20 | 736 | MODULE_ALIAS_MISCDEV(UHID_MINOR); |
60cbd53e | 737 | MODULE_ALIAS("devname:" UHID_NAME); |