1 /*
2 * f_hid.c -- USB HID function driver
3 *
4 * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 #include <linux/kernel.h>
22 #include <linux/utsname.h>
23 #include <linux/module.h>
24 #include <linux/hid.h>
25 #include <linux/cdev.h>
26 #include <linux/mutex.h>
27 #include <linux/poll.h>
28 #include <linux/uaccess.h>
29 #include <linux/wait.h>
30 #include <linux/usb/g_hid.h>
31
32 static int major, minors;
33 static struct class *hidg_class;
34
35 /*-------------------------------------------------------------------------*/
36 /* HID gadget struct */
37
38 struct f_hidg {
39 /* configuration */
40 unsigned char bInterfaceSubClass;
41 unsigned char bInterfaceProtocol;
42 unsigned short report_desc_length;
43 char *report_desc;
44 unsigned short report_length;
45
46 /* recv report */
47 char *set_report_buff;
48 unsigned short set_report_length;
49 spinlock_t spinlock;
50 wait_queue_head_t read_queue;
51
52 /* send report */
53 struct mutex lock;
54 bool write_pending;
55 wait_queue_head_t write_queue;
56 struct usb_request *req;
57
58 int minor;
59 struct cdev cdev;
60 struct usb_function func;
61 struct usb_ep *in_ep;
62 struct usb_endpoint_descriptor *fs_in_ep_desc;
63 struct usb_endpoint_descriptor *hs_in_ep_desc;
64 };
65
func_to_hidg(struct usb_function * f)66 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
67 {
68 return container_of(f, struct f_hidg, func);
69 }
70
71 /*-------------------------------------------------------------------------*/
72 /* Static descriptors */
73
74 static struct usb_interface_descriptor hidg_interface_desc = {
75 .bLength = sizeof hidg_interface_desc,
76 .bDescriptorType = USB_DT_INTERFACE,
77 /* .bInterfaceNumber = DYNAMIC */
78 .bAlternateSetting = 0,
79 .bNumEndpoints = 1,
80 .bInterfaceClass = USB_CLASS_HID,
81 /* .bInterfaceSubClass = DYNAMIC */
82 /* .bInterfaceProtocol = DYNAMIC */
83 /* .iInterface = DYNAMIC */
84 };
85
86 static struct hid_descriptor hidg_desc = {
87 .bLength = sizeof hidg_desc,
88 .bDescriptorType = HID_DT_HID,
89 .bcdHID = 0x0101,
90 .bCountryCode = 0x00,
91 .bNumDescriptors = 0x1,
92 /*.desc[0].bDescriptorType = DYNAMIC */
93 /*.desc[0].wDescriptorLenght = DYNAMIC */
94 };
95
96 /* High-Speed Support */
97
98 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
99 .bLength = USB_DT_ENDPOINT_SIZE,
100 .bDescriptorType = USB_DT_ENDPOINT,
101 .bEndpointAddress = USB_DIR_IN,
102 .bmAttributes = USB_ENDPOINT_XFER_INT,
103 /*.wMaxPacketSize = DYNAMIC */
104 .bInterval = 4, /* FIXME: Add this field in the
105 * HID gadget configuration?
106 * (struct hidg_func_descriptor)
107 */
108 };
109
110 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
111 (struct usb_descriptor_header *)&hidg_interface_desc,
112 (struct usb_descriptor_header *)&hidg_desc,
113 (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
114 NULL,
115 };
116
117 /* Full-Speed Support */
118
119 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
120 .bLength = USB_DT_ENDPOINT_SIZE,
121 .bDescriptorType = USB_DT_ENDPOINT,
122 .bEndpointAddress = USB_DIR_IN,
123 .bmAttributes = USB_ENDPOINT_XFER_INT,
124 /*.wMaxPacketSize = DYNAMIC */
125 .bInterval = 10, /* FIXME: Add this field in the
126 * HID gadget configuration?
127 * (struct hidg_func_descriptor)
128 */
129 };
130
131 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
132 (struct usb_descriptor_header *)&hidg_interface_desc,
133 (struct usb_descriptor_header *)&hidg_desc,
134 (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
135 NULL,
136 };
137
138 /*-------------------------------------------------------------------------*/
139 /* Char Device */
140
f_hidg_read(struct file * file,char __user * buffer,size_t count,loff_t * ptr)141 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
142 size_t count, loff_t *ptr)
143 {
144 struct f_hidg *hidg = file->private_data;
145 char *tmp_buff = NULL;
146 unsigned long flags;
147
148 if (!count)
149 return 0;
150
151 if (!access_ok(VERIFY_WRITE, buffer, count))
152 return -EFAULT;
153
154 spin_lock_irqsave(&hidg->spinlock, flags);
155
156 #define READ_COND (hidg->set_report_buff != NULL)
157
158 while (!READ_COND) {
159 spin_unlock_irqrestore(&hidg->spinlock, flags);
160 if (file->f_flags & O_NONBLOCK)
161 return -EAGAIN;
162
163 if (wait_event_interruptible(hidg->read_queue, READ_COND))
164 return -ERESTARTSYS;
165
166 spin_lock_irqsave(&hidg->spinlock, flags);
167 }
168
169
170 count = min_t(unsigned, count, hidg->set_report_length);
171 tmp_buff = hidg->set_report_buff;
172 hidg->set_report_buff = NULL;
173
174 spin_unlock_irqrestore(&hidg->spinlock, flags);
175
176 if (tmp_buff != NULL) {
177 /* copy to user outside spinlock */
178 count -= copy_to_user(buffer, tmp_buff, count);
179 kfree(tmp_buff);
180 } else
181 count = -ENOMEM;
182
183 return count;
184 }
185
f_hidg_req_complete(struct usb_ep * ep,struct usb_request * req)186 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
187 {
188 struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
189
190 if (req->status != 0) {
191 ERROR(hidg->func.config->cdev,
192 "End Point Request ERROR: %d\n", req->status);
193 }
194
195 hidg->write_pending = 0;
196 wake_up(&hidg->write_queue);
197 }
198
f_hidg_write(struct file * file,const char __user * buffer,size_t count,loff_t * offp)199 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
200 size_t count, loff_t *offp)
201 {
202 struct f_hidg *hidg = file->private_data;
203 ssize_t status = -ENOMEM;
204
205 if (!access_ok(VERIFY_READ, buffer, count))
206 return -EFAULT;
207
208 mutex_lock(&hidg->lock);
209
210 #define WRITE_COND (!hidg->write_pending)
211
212 /* write queue */
213 while (!WRITE_COND) {
214 mutex_unlock(&hidg->lock);
215 if (file->f_flags & O_NONBLOCK)
216 return -EAGAIN;
217
218 if (wait_event_interruptible_exclusive(
219 hidg->write_queue, WRITE_COND))
220 return -ERESTARTSYS;
221
222 mutex_lock(&hidg->lock);
223 }
224
225 count = min_t(unsigned, count, hidg->report_length);
226 status = copy_from_user(hidg->req->buf, buffer, count);
227
228 if (status != 0) {
229 ERROR(hidg->func.config->cdev,
230 "copy_from_user error\n");
231 mutex_unlock(&hidg->lock);
232 return -EINVAL;
233 }
234
235 hidg->req->status = 0;
236 hidg->req->zero = 0;
237 hidg->req->length = count;
238 hidg->req->complete = f_hidg_req_complete;
239 hidg->req->context = hidg;
240 hidg->write_pending = 1;
241
242 status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
243 if (status < 0) {
244 ERROR(hidg->func.config->cdev,
245 "usb_ep_queue error on int endpoint %zd\n", status);
246 hidg->write_pending = 0;
247 wake_up(&hidg->write_queue);
248 } else {
249 status = count;
250 }
251
252 mutex_unlock(&hidg->lock);
253
254 return status;
255 }
256
f_hidg_poll(struct file * file,poll_table * wait)257 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
258 {
259 struct f_hidg *hidg = file->private_data;
260 unsigned int ret = 0;
261
262 poll_wait(file, &hidg->read_queue, wait);
263 poll_wait(file, &hidg->write_queue, wait);
264
265 if (WRITE_COND)
266 ret |= POLLOUT | POLLWRNORM;
267
268 if (READ_COND)
269 ret |= POLLIN | POLLRDNORM;
270
271 return ret;
272 }
273
274 #undef WRITE_COND
275 #undef READ_COND
276
f_hidg_release(struct inode * inode,struct file * fd)277 static int f_hidg_release(struct inode *inode, struct file *fd)
278 {
279 fd->private_data = NULL;
280 return 0;
281 }
282
f_hidg_open(struct inode * inode,struct file * fd)283 static int f_hidg_open(struct inode *inode, struct file *fd)
284 {
285 struct f_hidg *hidg =
286 container_of(inode->i_cdev, struct f_hidg, cdev);
287
288 fd->private_data = hidg;
289
290 return 0;
291 }
292
293 /*-------------------------------------------------------------------------*/
294 /* usb_function */
295
hidg_set_report_complete(struct usb_ep * ep,struct usb_request * req)296 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
297 {
298 struct f_hidg *hidg = (struct f_hidg *)req->context;
299
300 if (req->status != 0 || req->buf == NULL || req->actual == 0) {
301 ERROR(hidg->func.config->cdev, "%s FAILED\n", __func__);
302 return;
303 }
304
305 spin_lock(&hidg->spinlock);
306
307 hidg->set_report_buff = krealloc(hidg->set_report_buff,
308 req->actual, GFP_ATOMIC);
309
310 if (hidg->set_report_buff == NULL) {
311 spin_unlock(&hidg->spinlock);
312 return;
313 }
314 hidg->set_report_length = req->actual;
315 memcpy(hidg->set_report_buff, req->buf, req->actual);
316
317 spin_unlock(&hidg->spinlock);
318
319 wake_up(&hidg->read_queue);
320 }
321
hidg_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)322 static int hidg_setup(struct usb_function *f,
323 const struct usb_ctrlrequest *ctrl)
324 {
325 struct f_hidg *hidg = func_to_hidg(f);
326 struct usb_composite_dev *cdev = f->config->cdev;
327 struct usb_request *req = cdev->req;
328 int status = 0;
329 __u16 value, length;
330
331 value = __le16_to_cpu(ctrl->wValue);
332 length = __le16_to_cpu(ctrl->wLength);
333
334 VDBG(cdev, "hid_setup crtl_request : bRequestType:0x%x bRequest:0x%x "
335 "Value:0x%x\n", ctrl->bRequestType, ctrl->bRequest, value);
336
337 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
338 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
339 | HID_REQ_GET_REPORT):
340 VDBG(cdev, "get_report\n");
341
342 /* send an empty report */
343 length = min_t(unsigned, length, hidg->report_length);
344 memset(req->buf, 0x0, length);
345
346 goto respond;
347 break;
348
349 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
350 | HID_REQ_GET_PROTOCOL):
351 VDBG(cdev, "get_protocol\n");
352 goto stall;
353 break;
354
355 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
356 | HID_REQ_SET_REPORT):
357 VDBG(cdev, "set_report | wLenght=%d\n", ctrl->wLength);
358 req->context = hidg;
359 req->complete = hidg_set_report_complete;
360 goto respond;
361 break;
362
363 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
364 | HID_REQ_SET_PROTOCOL):
365 VDBG(cdev, "set_protocol\n");
366 goto stall;
367 break;
368
369 case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
370 | USB_REQ_GET_DESCRIPTOR):
371 switch (value >> 8) {
372 case HID_DT_REPORT:
373 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
374 length = min_t(unsigned short, length,
375 hidg->report_desc_length);
376 memcpy(req->buf, hidg->report_desc, length);
377 goto respond;
378 break;
379
380 default:
381 VDBG(cdev, "Unknown decriptor request 0x%x\n",
382 value >> 8);
383 goto stall;
384 break;
385 }
386 break;
387
388 default:
389 VDBG(cdev, "Unknown request 0x%x\n",
390 ctrl->bRequest);
391 goto stall;
392 break;
393 }
394
395 stall:
396 return -EOPNOTSUPP;
397
398 respond:
399 req->zero = 0;
400 req->length = length;
401 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
402 if (status < 0)
403 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
404 return status;
405 }
406
hidg_disable(struct usb_function * f)407 static void hidg_disable(struct usb_function *f)
408 {
409 struct f_hidg *hidg = func_to_hidg(f);
410
411 usb_ep_disable(hidg->in_ep);
412 hidg->in_ep->driver_data = NULL;
413 }
414
hidg_set_alt(struct usb_function * f,unsigned intf,unsigned alt)415 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
416 {
417 struct usb_composite_dev *cdev = f->config->cdev;
418 struct f_hidg *hidg = func_to_hidg(f);
419 const struct usb_endpoint_descriptor *ep_desc;
420 int status = 0;
421
422 VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
423
424 if (hidg->in_ep != NULL) {
425 /* restart endpoint */
426 if (hidg->in_ep->driver_data != NULL)
427 usb_ep_disable(hidg->in_ep);
428
429 ep_desc = ep_choose(f->config->cdev->gadget,
430 hidg->hs_in_ep_desc, hidg->fs_in_ep_desc);
431 status = usb_ep_enable(hidg->in_ep, ep_desc);
432 if (status < 0) {
433 ERROR(cdev, "Enable endpoint FAILED!\n");
434 goto fail;
435 }
436 hidg->in_ep->driver_data = hidg;
437 }
438 fail:
439 return status;
440 }
441
442 const struct file_operations f_hidg_fops = {
443 .owner = THIS_MODULE,
444 .open = f_hidg_open,
445 .release = f_hidg_release,
446 .write = f_hidg_write,
447 .read = f_hidg_read,
448 .poll = f_hidg_poll,
449 .llseek = noop_llseek,
450 };
451
hidg_bind(struct usb_configuration * c,struct usb_function * f)452 static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f)
453 {
454 struct usb_ep *ep;
455 struct f_hidg *hidg = func_to_hidg(f);
456 int status;
457 dev_t dev;
458
459 /* allocate instance-specific interface IDs, and patch descriptors */
460 status = usb_interface_id(c, f);
461 if (status < 0)
462 goto fail;
463 hidg_interface_desc.bInterfaceNumber = status;
464
465
466 /* allocate instance-specific endpoints */
467 status = -ENODEV;
468 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
469 if (!ep)
470 goto fail;
471 ep->driver_data = c->cdev; /* claim */
472 hidg->in_ep = ep;
473
474 /* preallocate request and buffer */
475 status = -ENOMEM;
476 hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
477 if (!hidg->req)
478 goto fail;
479
480
481 hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
482 if (!hidg->req->buf)
483 goto fail;
484
485 /* set descriptor dynamic values */
486 hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
487 hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
488 hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
489 hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
490 hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
491 hidg_desc.desc[0].wDescriptorLength =
492 cpu_to_le16(hidg->report_desc_length);
493
494 hidg->set_report_buff = NULL;
495
496 /* copy descriptors */
497 f->descriptors = usb_copy_descriptors(hidg_fs_descriptors);
498 if (!f->descriptors)
499 goto fail;
500
501 hidg->fs_in_ep_desc = usb_find_endpoint(hidg_fs_descriptors,
502 f->descriptors,
503 &hidg_fs_in_ep_desc);
504
505 if (gadget_is_dualspeed(c->cdev->gadget)) {
506 hidg_hs_in_ep_desc.bEndpointAddress =
507 hidg_fs_in_ep_desc.bEndpointAddress;
508 f->hs_descriptors = usb_copy_descriptors(hidg_hs_descriptors);
509 if (!f->hs_descriptors)
510 goto fail;
511 hidg->hs_in_ep_desc = usb_find_endpoint(hidg_hs_descriptors,
512 f->hs_descriptors,
513 &hidg_hs_in_ep_desc);
514 } else {
515 hidg->hs_in_ep_desc = NULL;
516 }
517
518 mutex_init(&hidg->lock);
519 spin_lock_init(&hidg->spinlock);
520 init_waitqueue_head(&hidg->write_queue);
521 init_waitqueue_head(&hidg->read_queue);
522
523 /* create char device */
524 cdev_init(&hidg->cdev, &f_hidg_fops);
525 dev = MKDEV(major, hidg->minor);
526 status = cdev_add(&hidg->cdev, dev, 1);
527 if (status)
528 goto fail;
529
530 device_create(hidg_class, NULL, dev, NULL, "%s%d", "hidg", hidg->minor);
531
532 return 0;
533
534 fail:
535 ERROR(f->config->cdev, "hidg_bind FAILED\n");
536 if (hidg->req != NULL) {
537 kfree(hidg->req->buf);
538 if (hidg->in_ep != NULL)
539 usb_ep_free_request(hidg->in_ep, hidg->req);
540 }
541
542 usb_free_descriptors(f->hs_descriptors);
543 usb_free_descriptors(f->descriptors);
544
545 return status;
546 }
547
hidg_unbind(struct usb_configuration * c,struct usb_function * f)548 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
549 {
550 struct f_hidg *hidg = func_to_hidg(f);
551
552 device_destroy(hidg_class, MKDEV(major, hidg->minor));
553 cdev_del(&hidg->cdev);
554
555 /* disable/free request and end point */
556 usb_ep_disable(hidg->in_ep);
557 usb_ep_dequeue(hidg->in_ep, hidg->req);
558 kfree(hidg->req->buf);
559 usb_ep_free_request(hidg->in_ep, hidg->req);
560
561 /* free descriptors copies */
562 usb_free_descriptors(f->hs_descriptors);
563 usb_free_descriptors(f->descriptors);
564
565 kfree(hidg->report_desc);
566 kfree(hidg->set_report_buff);
567 kfree(hidg);
568 }
569
570 /*-------------------------------------------------------------------------*/
571 /* Strings */
572
573 #define CT_FUNC_HID_IDX 0
574
575 static struct usb_string ct_func_string_defs[] = {
576 [CT_FUNC_HID_IDX].s = "HID Interface",
577 {}, /* end of list */
578 };
579
580 static struct usb_gadget_strings ct_func_string_table = {
581 .language = 0x0409, /* en-US */
582 .strings = ct_func_string_defs,
583 };
584
585 static struct usb_gadget_strings *ct_func_strings[] = {
586 &ct_func_string_table,
587 NULL,
588 };
589
590 /*-------------------------------------------------------------------------*/
591 /* usb_configuration */
592
hidg_bind_config(struct usb_configuration * c,struct hidg_func_descriptor * fdesc,int index)593 int __init hidg_bind_config(struct usb_configuration *c,
594 struct hidg_func_descriptor *fdesc, int index)
595 {
596 struct f_hidg *hidg;
597 int status;
598
599 if (index >= minors)
600 return -ENOENT;
601
602 /* maybe allocate device-global string IDs, and patch descriptors */
603 if (ct_func_string_defs[CT_FUNC_HID_IDX].id == 0) {
604 status = usb_string_id(c->cdev);
605 if (status < 0)
606 return status;
607 ct_func_string_defs[CT_FUNC_HID_IDX].id = status;
608 hidg_interface_desc.iInterface = status;
609 }
610
611 /* allocate and initialize one new instance */
612 hidg = kzalloc(sizeof *hidg, GFP_KERNEL);
613 if (!hidg)
614 return -ENOMEM;
615
616 hidg->minor = index;
617 hidg->bInterfaceSubClass = fdesc->subclass;
618 hidg->bInterfaceProtocol = fdesc->protocol;
619 hidg->report_length = fdesc->report_length;
620 hidg->report_desc_length = fdesc->report_desc_length;
621 hidg->report_desc = kmemdup(fdesc->report_desc,
622 fdesc->report_desc_length,
623 GFP_KERNEL);
624 if (!hidg->report_desc) {
625 kfree(hidg);
626 return -ENOMEM;
627 }
628
629 hidg->func.name = "hid";
630 hidg->func.strings = ct_func_strings;
631 hidg->func.bind = hidg_bind;
632 hidg->func.unbind = hidg_unbind;
633 hidg->func.set_alt = hidg_set_alt;
634 hidg->func.disable = hidg_disable;
635 hidg->func.setup = hidg_setup;
636
637 status = usb_add_function(c, &hidg->func);
638 if (status)
639 kfree(hidg);
640
641 return status;
642 }
643
ghid_setup(struct usb_gadget * g,int count)644 int __init ghid_setup(struct usb_gadget *g, int count)
645 {
646 int status;
647 dev_t dev;
648
649 hidg_class = class_create(THIS_MODULE, "hidg");
650
651 status = alloc_chrdev_region(&dev, 0, count, "hidg");
652 if (!status) {
653 major = MAJOR(dev);
654 minors = count;
655 }
656
657 return status;
658 }
659
ghid_cleanup(void)660 void ghid_cleanup(void)
661 {
662 if (major) {
663 unregister_chrdev_region(MKDEV(major, 0), minors);
664 major = minors = 0;
665 }
666
667 class_destroy(hidg_class);
668 hidg_class = NULL;
669 }
670