1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * f_hid.c -- USB HID function driver
4  *
5  * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/hid.h>
11 #include <linux/idr.h>
12 #include <linux/cdev.h>
13 #include <linux/mutex.h>
14 #include <linux/poll.h>
15 #include <linux/uaccess.h>
16 #include <linux/wait.h>
17 #include <linux/sched.h>
18 #include <linux/usb/g_hid.h>
19 
20 #include "u_f.h"
21 #include "u_hid.h"
22 
23 #define HIDG_MINORS	4
24 
25 static int major, minors;
26 
27 static const struct class hidg_class = {
28 	.name = "hidg",
29 };
30 
31 static DEFINE_IDA(hidg_ida);
32 static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
33 
34 /*-------------------------------------------------------------------------*/
35 /*                            HID gadget struct                            */
36 
37 struct f_hidg_req_list {
38 	struct usb_request	*req;
39 	unsigned int		pos;
40 	struct list_head 	list;
41 };
42 
43 struct f_hidg {
44 	/* configuration */
45 	unsigned char			bInterfaceSubClass;
46 	unsigned char			bInterfaceProtocol;
47 	unsigned char			protocol;
48 	unsigned char			idle;
49 	unsigned short			report_desc_length;
50 	char				*report_desc;
51 	unsigned short			report_length;
52 	/*
53 	 * use_out_ep - if true, the OUT Endpoint (interrupt out method)
54 	 *              will be used to receive reports from the host
55 	 *              using functions with the "intout" suffix.
56 	 *              Otherwise, the OUT Endpoint will not be configured
57 	 *              and the SETUP/SET_REPORT method ("ssreport" suffix)
58 	 *              will be used to receive reports.
59 	 */
60 	bool				use_out_ep;
61 
62 	/* recv report */
63 	spinlock_t			read_spinlock;
64 	wait_queue_head_t		read_queue;
65 	/* recv report - interrupt out only (use_out_ep == 1) */
66 	struct list_head		completed_out_req;
67 	unsigned int			qlen;
68 	/* recv report - setup set_report only (use_out_ep == 0) */
69 	char				*set_report_buf;
70 	unsigned int			set_report_length;
71 
72 	/* send report */
73 	spinlock_t			write_spinlock;
74 	bool				write_pending;
75 	wait_queue_head_t		write_queue;
76 	struct usb_request		*req;
77 
78 	struct device			dev;
79 	struct cdev			cdev;
80 	struct usb_function		func;
81 
82 	struct usb_ep			*in_ep;
83 	struct usb_ep			*out_ep;
84 };
85 
86 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
87 {
88 	return container_of(f, struct f_hidg, func);
89 }
90 
91 static void hidg_release(struct device *dev)
92 {
93 	struct f_hidg *hidg = container_of(dev, struct f_hidg, dev);
94 
95 	kfree(hidg->report_desc);
96 	kfree(hidg->set_report_buf);
97 	kfree(hidg);
98 }
99 
100 /*-------------------------------------------------------------------------*/
101 /*                           Static descriptors                            */
102 
103 static struct usb_interface_descriptor hidg_interface_desc = {
104 	.bLength		= sizeof hidg_interface_desc,
105 	.bDescriptorType	= USB_DT_INTERFACE,
106 	/* .bInterfaceNumber	= DYNAMIC */
107 	.bAlternateSetting	= 0,
108 	/* .bNumEndpoints	= DYNAMIC (depends on use_out_ep) */
109 	.bInterfaceClass	= USB_CLASS_HID,
110 	/* .bInterfaceSubClass	= DYNAMIC */
111 	/* .bInterfaceProtocol	= DYNAMIC */
112 	/* .iInterface		= DYNAMIC */
113 };
114 
115 static struct hid_descriptor hidg_desc = {
116 	.bLength			= sizeof hidg_desc,
117 	.bDescriptorType		= HID_DT_HID,
118 	.bcdHID				= cpu_to_le16(0x0101),
119 	.bCountryCode			= 0x00,
120 	.bNumDescriptors		= 0x1,
121 	/*.desc[0].bDescriptorType	= DYNAMIC */
122 	/*.desc[0].wDescriptorLenght	= DYNAMIC */
123 };
124 
125 /* Super-Speed Support */
126 
127 static struct usb_endpoint_descriptor hidg_ss_in_ep_desc = {
128 	.bLength		= USB_DT_ENDPOINT_SIZE,
129 	.bDescriptorType	= USB_DT_ENDPOINT,
130 	.bEndpointAddress	= USB_DIR_IN,
131 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
132 	/*.wMaxPacketSize	= DYNAMIC */
133 	.bInterval		= 4, /* FIXME: Add this field in the
134 				      * HID gadget configuration?
135 				      * (struct hidg_func_descriptor)
136 				      */
137 };
138 
139 static struct usb_ss_ep_comp_descriptor hidg_ss_in_comp_desc = {
140 	.bLength                = sizeof(hidg_ss_in_comp_desc),
141 	.bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
142 
143 	/* .bMaxBurst           = 0, */
144 	/* .bmAttributes        = 0, */
145 	/* .wBytesPerInterval   = DYNAMIC */
146 };
147 
148 static struct usb_endpoint_descriptor hidg_ss_out_ep_desc = {
149 	.bLength		= USB_DT_ENDPOINT_SIZE,
150 	.bDescriptorType	= USB_DT_ENDPOINT,
151 	.bEndpointAddress	= USB_DIR_OUT,
152 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
153 	/*.wMaxPacketSize	= DYNAMIC */
154 	.bInterval		= 4, /* FIXME: Add this field in the
155 				      * HID gadget configuration?
156 				      * (struct hidg_func_descriptor)
157 				      */
158 };
159 
160 static struct usb_ss_ep_comp_descriptor hidg_ss_out_comp_desc = {
161 	.bLength                = sizeof(hidg_ss_out_comp_desc),
162 	.bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
163 
164 	/* .bMaxBurst           = 0, */
165 	/* .bmAttributes        = 0, */
166 	/* .wBytesPerInterval   = DYNAMIC */
167 };
168 
169 static struct usb_descriptor_header *hidg_ss_descriptors_intout[] = {
170 	(struct usb_descriptor_header *)&hidg_interface_desc,
171 	(struct usb_descriptor_header *)&hidg_desc,
172 	(struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
173 	(struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
174 	(struct usb_descriptor_header *)&hidg_ss_out_ep_desc,
175 	(struct usb_descriptor_header *)&hidg_ss_out_comp_desc,
176 	NULL,
177 };
178 
179 static struct usb_descriptor_header *hidg_ss_descriptors_ssreport[] = {
180 	(struct usb_descriptor_header *)&hidg_interface_desc,
181 	(struct usb_descriptor_header *)&hidg_desc,
182 	(struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
183 	(struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
184 	NULL,
185 };
186 
187 /* High-Speed Support */
188 
189 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
190 	.bLength		= USB_DT_ENDPOINT_SIZE,
191 	.bDescriptorType	= USB_DT_ENDPOINT,
192 	.bEndpointAddress	= USB_DIR_IN,
193 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
194 	/*.wMaxPacketSize	= DYNAMIC */
195 	.bInterval		= 4, /* FIXME: Add this field in the
196 				      * HID gadget configuration?
197 				      * (struct hidg_func_descriptor)
198 				      */
199 };
200 
201 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
202 	.bLength		= USB_DT_ENDPOINT_SIZE,
203 	.bDescriptorType	= USB_DT_ENDPOINT,
204 	.bEndpointAddress	= USB_DIR_OUT,
205 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
206 	/*.wMaxPacketSize	= DYNAMIC */
207 	.bInterval		= 4, /* FIXME: Add this field in the
208 				      * HID gadget configuration?
209 				      * (struct hidg_func_descriptor)
210 				      */
211 };
212 
213 static struct usb_descriptor_header *hidg_hs_descriptors_intout[] = {
214 	(struct usb_descriptor_header *)&hidg_interface_desc,
215 	(struct usb_descriptor_header *)&hidg_desc,
216 	(struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
217 	(struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
218 	NULL,
219 };
220 
221 static struct usb_descriptor_header *hidg_hs_descriptors_ssreport[] = {
222 	(struct usb_descriptor_header *)&hidg_interface_desc,
223 	(struct usb_descriptor_header *)&hidg_desc,
224 	(struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
225 	NULL,
226 };
227 
228 /* Full-Speed Support */
229 
230 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
231 	.bLength		= USB_DT_ENDPOINT_SIZE,
232 	.bDescriptorType	= USB_DT_ENDPOINT,
233 	.bEndpointAddress	= USB_DIR_IN,
234 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
235 	/*.wMaxPacketSize	= DYNAMIC */
236 	.bInterval		= 10, /* FIXME: Add this field in the
237 				       * HID gadget configuration?
238 				       * (struct hidg_func_descriptor)
239 				       */
240 };
241 
242 static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
243 	.bLength		= USB_DT_ENDPOINT_SIZE,
244 	.bDescriptorType	= USB_DT_ENDPOINT,
245 	.bEndpointAddress	= USB_DIR_OUT,
246 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
247 	/*.wMaxPacketSize	= DYNAMIC */
248 	.bInterval		= 10, /* FIXME: Add this field in the
249 				       * HID gadget configuration?
250 				       * (struct hidg_func_descriptor)
251 				       */
252 };
253 
254 static struct usb_descriptor_header *hidg_fs_descriptors_intout[] = {
255 	(struct usb_descriptor_header *)&hidg_interface_desc,
256 	(struct usb_descriptor_header *)&hidg_desc,
257 	(struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
258 	(struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
259 	NULL,
260 };
261 
262 static struct usb_descriptor_header *hidg_fs_descriptors_ssreport[] = {
263 	(struct usb_descriptor_header *)&hidg_interface_desc,
264 	(struct usb_descriptor_header *)&hidg_desc,
265 	(struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
266 	NULL,
267 };
268 
269 /*-------------------------------------------------------------------------*/
270 /*                                 Strings                                 */
271 
272 #define CT_FUNC_HID_IDX	0
273 
274 static struct usb_string ct_func_string_defs[] = {
275 	[CT_FUNC_HID_IDX].s	= "HID Interface",
276 	{},			/* end of list */
277 };
278 
279 static struct usb_gadget_strings ct_func_string_table = {
280 	.language	= 0x0409,	/* en-US */
281 	.strings	= ct_func_string_defs,
282 };
283 
284 static struct usb_gadget_strings *ct_func_strings[] = {
285 	&ct_func_string_table,
286 	NULL,
287 };
288 
289 /*-------------------------------------------------------------------------*/
290 /*                              Char Device                                */
291 
292 static ssize_t f_hidg_intout_read(struct file *file, char __user *buffer,
293 				  size_t count, loff_t *ptr)
294 {
295 	struct f_hidg *hidg = file->private_data;
296 	struct f_hidg_req_list *list;
297 	struct usb_request *req;
298 	unsigned long flags;
299 	int ret;
300 
301 	if (!count)
302 		return 0;
303 
304 	spin_lock_irqsave(&hidg->read_spinlock, flags);
305 
306 #define READ_COND_INTOUT (!list_empty(&hidg->completed_out_req))
307 
308 	/* wait for at least one buffer to complete */
309 	while (!READ_COND_INTOUT) {
310 		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
311 		if (file->f_flags & O_NONBLOCK)
312 			return -EAGAIN;
313 
314 		if (wait_event_interruptible(hidg->read_queue, READ_COND_INTOUT))
315 			return -ERESTARTSYS;
316 
317 		spin_lock_irqsave(&hidg->read_spinlock, flags);
318 	}
319 
320 	/* pick the first one */
321 	list = list_first_entry(&hidg->completed_out_req,
322 				struct f_hidg_req_list, list);
323 
324 	/*
325 	 * Remove this from list to protect it from beign free()
326 	 * while host disables our function
327 	 */
328 	list_del(&list->list);
329 
330 	req = list->req;
331 	count = min_t(unsigned int, count, req->actual - list->pos);
332 	spin_unlock_irqrestore(&hidg->read_spinlock, flags);
333 
334 	/* copy to user outside spinlock */
335 	count -= copy_to_user(buffer, req->buf + list->pos, count);
336 	list->pos += count;
337 
338 	/*
339 	 * if this request is completely handled and transfered to
340 	 * userspace, remove its entry from the list and requeue it
341 	 * again. Otherwise, we will revisit it again upon the next
342 	 * call, taking into account its current read position.
343 	 */
344 	if (list->pos == req->actual) {
345 		kfree(list);
346 
347 		req->length = hidg->report_length;
348 		ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
349 		if (ret < 0) {
350 			free_ep_req(hidg->out_ep, req);
351 			return ret;
352 		}
353 	} else {
354 		spin_lock_irqsave(&hidg->read_spinlock, flags);
355 		list_add(&list->list, &hidg->completed_out_req);
356 		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
357 
358 		wake_up(&hidg->read_queue);
359 	}
360 
361 	return count;
362 }
363 
364 #define READ_COND_SSREPORT (hidg->set_report_buf != NULL)
365 
366 static ssize_t f_hidg_ssreport_read(struct file *file, char __user *buffer,
367 				    size_t count, loff_t *ptr)
368 {
369 	struct f_hidg *hidg = file->private_data;
370 	char *tmp_buf = NULL;
371 	unsigned long flags;
372 
373 	if (!count)
374 		return 0;
375 
376 	spin_lock_irqsave(&hidg->read_spinlock, flags);
377 
378 	while (!READ_COND_SSREPORT) {
379 		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
380 		if (file->f_flags & O_NONBLOCK)
381 			return -EAGAIN;
382 
383 		if (wait_event_interruptible(hidg->read_queue, READ_COND_SSREPORT))
384 			return -ERESTARTSYS;
385 
386 		spin_lock_irqsave(&hidg->read_spinlock, flags);
387 	}
388 
389 	count = min_t(unsigned int, count, hidg->set_report_length);
390 	tmp_buf = hidg->set_report_buf;
391 	hidg->set_report_buf = NULL;
392 
393 	spin_unlock_irqrestore(&hidg->read_spinlock, flags);
394 
395 	if (tmp_buf != NULL) {
396 		count -= copy_to_user(buffer, tmp_buf, count);
397 		kfree(tmp_buf);
398 	} else {
399 		count = -ENOMEM;
400 	}
401 
402 	wake_up(&hidg->read_queue);
403 
404 	return count;
405 }
406 
407 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
408 			   size_t count, loff_t *ptr)
409 {
410 	struct f_hidg *hidg = file->private_data;
411 
412 	if (hidg->use_out_ep)
413 		return f_hidg_intout_read(file, buffer, count, ptr);
414 	else
415 		return f_hidg_ssreport_read(file, buffer, count, ptr);
416 }
417 
418 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
419 {
420 	struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
421 	unsigned long flags;
422 
423 	if (req->status != 0) {
424 		ERROR(hidg->func.config->cdev,
425 			"End Point Request ERROR: %d\n", req->status);
426 	}
427 
428 	spin_lock_irqsave(&hidg->write_spinlock, flags);
429 	hidg->write_pending = 0;
430 	spin_unlock_irqrestore(&hidg->write_spinlock, flags);
431 	wake_up(&hidg->write_queue);
432 }
433 
434 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
435 			    size_t count, loff_t *offp)
436 {
437 	struct f_hidg *hidg  = file->private_data;
438 	struct usb_request *req;
439 	unsigned long flags;
440 	ssize_t status = -ENOMEM;
441 
442 	spin_lock_irqsave(&hidg->write_spinlock, flags);
443 
444 	if (!hidg->req) {
445 		spin_unlock_irqrestore(&hidg->write_spinlock, flags);
446 		return -ESHUTDOWN;
447 	}
448 
449 #define WRITE_COND (!hidg->write_pending)
450 try_again:
451 	/* write queue */
452 	while (!WRITE_COND) {
453 		spin_unlock_irqrestore(&hidg->write_spinlock, flags);
454 		if (file->f_flags & O_NONBLOCK)
455 			return -EAGAIN;
456 
457 		if (wait_event_interruptible_exclusive(
458 				hidg->write_queue, WRITE_COND))
459 			return -ERESTARTSYS;
460 
461 		spin_lock_irqsave(&hidg->write_spinlock, flags);
462 	}
463 
464 	hidg->write_pending = 1;
465 	req = hidg->req;
466 	count  = min_t(unsigned, count, hidg->report_length);
467 
468 	spin_unlock_irqrestore(&hidg->write_spinlock, flags);
469 
470 	if (!req) {
471 		ERROR(hidg->func.config->cdev, "hidg->req is NULL\n");
472 		status = -ESHUTDOWN;
473 		goto release_write_pending;
474 	}
475 
476 	status = copy_from_user(req->buf, buffer, count);
477 	if (status != 0) {
478 		ERROR(hidg->func.config->cdev,
479 			"copy_from_user error\n");
480 		status = -EINVAL;
481 		goto release_write_pending;
482 	}
483 
484 	spin_lock_irqsave(&hidg->write_spinlock, flags);
485 
486 	/* when our function has been disabled by host */
487 	if (!hidg->req) {
488 		free_ep_req(hidg->in_ep, req);
489 		/*
490 		 * TODO
491 		 * Should we fail with error here?
492 		 */
493 		goto try_again;
494 	}
495 
496 	req->status   = 0;
497 	req->zero     = 0;
498 	req->length   = count;
499 	req->complete = f_hidg_req_complete;
500 	req->context  = hidg;
501 
502 	spin_unlock_irqrestore(&hidg->write_spinlock, flags);
503 
504 	if (!hidg->in_ep->enabled) {
505 		ERROR(hidg->func.config->cdev, "in_ep is disabled\n");
506 		status = -ESHUTDOWN;
507 		goto release_write_pending;
508 	}
509 
510 	status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
511 	if (status < 0)
512 		goto release_write_pending;
513 	else
514 		status = count;
515 
516 	return status;
517 release_write_pending:
518 	spin_lock_irqsave(&hidg->write_spinlock, flags);
519 	hidg->write_pending = 0;
520 	spin_unlock_irqrestore(&hidg->write_spinlock, flags);
521 
522 	wake_up(&hidg->write_queue);
523 
524 	return status;
525 }
526 
527 static __poll_t f_hidg_poll(struct file *file, poll_table *wait)
528 {
529 	struct f_hidg	*hidg  = file->private_data;
530 	__poll_t	ret = 0;
531 
532 	poll_wait(file, &hidg->read_queue, wait);
533 	poll_wait(file, &hidg->write_queue, wait);
534 
535 	if (WRITE_COND)
536 		ret |= EPOLLOUT | EPOLLWRNORM;
537 
538 	if (hidg->use_out_ep) {
539 		if (READ_COND_INTOUT)
540 			ret |= EPOLLIN | EPOLLRDNORM;
541 	} else {
542 		if (READ_COND_SSREPORT)
543 			ret |= EPOLLIN | EPOLLRDNORM;
544 	}
545 
546 	return ret;
547 }
548 
549 #undef WRITE_COND
550 #undef READ_COND_SSREPORT
551 #undef READ_COND_INTOUT
552 
553 static int f_hidg_release(struct inode *inode, struct file *fd)
554 {
555 	fd->private_data = NULL;
556 	return 0;
557 }
558 
559 static int f_hidg_open(struct inode *inode, struct file *fd)
560 {
561 	struct f_hidg *hidg =
562 		container_of(inode->i_cdev, struct f_hidg, cdev);
563 
564 	fd->private_data = hidg;
565 
566 	return 0;
567 }
568 
569 /*-------------------------------------------------------------------------*/
570 /*                                usb_function                             */
571 
572 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
573 						    unsigned length)
574 {
575 	return alloc_ep_req(ep, length);
576 }
577 
578 static void hidg_intout_complete(struct usb_ep *ep, struct usb_request *req)
579 {
580 	struct f_hidg *hidg = (struct f_hidg *) req->context;
581 	struct usb_composite_dev *cdev = hidg->func.config->cdev;
582 	struct f_hidg_req_list *req_list;
583 	unsigned long flags;
584 
585 	switch (req->status) {
586 	case 0:
587 		req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
588 		if (!req_list) {
589 			ERROR(cdev, "Unable to allocate mem for req_list\n");
590 			goto free_req;
591 		}
592 
593 		req_list->req = req;
594 
595 		spin_lock_irqsave(&hidg->read_spinlock, flags);
596 		list_add_tail(&req_list->list, &hidg->completed_out_req);
597 		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
598 
599 		wake_up(&hidg->read_queue);
600 		break;
601 	default:
602 		ERROR(cdev, "Set report failed %d\n", req->status);
603 		fallthrough;
604 	case -ECONNABORTED:		/* hardware forced ep reset */
605 	case -ECONNRESET:		/* request dequeued */
606 	case -ESHUTDOWN:		/* disconnect from host */
607 free_req:
608 		free_ep_req(ep, req);
609 		return;
610 	}
611 }
612 
613 static void hidg_ssreport_complete(struct usb_ep *ep, struct usb_request *req)
614 {
615 	struct f_hidg *hidg = (struct f_hidg *)req->context;
616 	struct usb_composite_dev *cdev = hidg->func.config->cdev;
617 	char *new_buf = NULL;
618 	unsigned long flags;
619 
620 	if (req->status != 0 || req->buf == NULL || req->actual == 0) {
621 		ERROR(cdev,
622 		      "%s FAILED: status=%d, buf=%p, actual=%d\n",
623 		      __func__, req->status, req->buf, req->actual);
624 		return;
625 	}
626 
627 	spin_lock_irqsave(&hidg->read_spinlock, flags);
628 
629 	new_buf = krealloc(hidg->set_report_buf, req->actual, GFP_ATOMIC);
630 	if (new_buf == NULL) {
631 		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
632 		return;
633 	}
634 	hidg->set_report_buf = new_buf;
635 
636 	hidg->set_report_length = req->actual;
637 	memcpy(hidg->set_report_buf, req->buf, req->actual);
638 
639 	spin_unlock_irqrestore(&hidg->read_spinlock, flags);
640 
641 	wake_up(&hidg->read_queue);
642 }
643 
644 static int hidg_setup(struct usb_function *f,
645 		const struct usb_ctrlrequest *ctrl)
646 {
647 	struct f_hidg			*hidg = func_to_hidg(f);
648 	struct usb_composite_dev	*cdev = f->config->cdev;
649 	struct usb_request		*req  = cdev->req;
650 	int status = 0;
651 	__u16 value, length;
652 
653 	value	= __le16_to_cpu(ctrl->wValue);
654 	length	= __le16_to_cpu(ctrl->wLength);
655 
656 	VDBG(cdev,
657 	     "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
658 	     __func__, ctrl->bRequestType, ctrl->bRequest, value);
659 
660 	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
661 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
662 		  | HID_REQ_GET_REPORT):
663 		VDBG(cdev, "get_report\n");
664 
665 		/* send an empty report */
666 		length = min_t(unsigned, length, hidg->report_length);
667 		memset(req->buf, 0x0, length);
668 
669 		goto respond;
670 		break;
671 
672 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
673 		  | HID_REQ_GET_PROTOCOL):
674 		VDBG(cdev, "get_protocol\n");
675 		length = min_t(unsigned int, length, 1);
676 		((u8 *) req->buf)[0] = hidg->protocol;
677 		goto respond;
678 		break;
679 
680 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
681 		  | HID_REQ_GET_IDLE):
682 		VDBG(cdev, "get_idle\n");
683 		length = min_t(unsigned int, length, 1);
684 		((u8 *) req->buf)[0] = hidg->idle;
685 		goto respond;
686 		break;
687 
688 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
689 		  | HID_REQ_SET_REPORT):
690 		VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
691 		if (hidg->use_out_ep)
692 			goto stall;
693 		req->complete = hidg_ssreport_complete;
694 		req->context  = hidg;
695 		goto respond;
696 		break;
697 
698 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
699 		  | HID_REQ_SET_PROTOCOL):
700 		VDBG(cdev, "set_protocol\n");
701 		if (value > HID_REPORT_PROTOCOL)
702 			goto stall;
703 		length = 0;
704 		/*
705 		 * We assume that programs implementing the Boot protocol
706 		 * are also compatible with the Report Protocol
707 		 */
708 		if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) {
709 			hidg->protocol = value;
710 			goto respond;
711 		}
712 		goto stall;
713 		break;
714 
715 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
716 		  | HID_REQ_SET_IDLE):
717 		VDBG(cdev, "set_idle\n");
718 		length = 0;
719 		hidg->idle = value >> 8;
720 		goto respond;
721 		break;
722 
723 	case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
724 		  | USB_REQ_GET_DESCRIPTOR):
725 		switch (value >> 8) {
726 		case HID_DT_HID:
727 		{
728 			struct hid_descriptor hidg_desc_copy = hidg_desc;
729 
730 			VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
731 			hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
732 			hidg_desc_copy.desc[0].wDescriptorLength =
733 				cpu_to_le16(hidg->report_desc_length);
734 
735 			length = min_t(unsigned short, length,
736 						   hidg_desc_copy.bLength);
737 			memcpy(req->buf, &hidg_desc_copy, length);
738 			goto respond;
739 			break;
740 		}
741 		case HID_DT_REPORT:
742 			VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
743 			length = min_t(unsigned short, length,
744 						   hidg->report_desc_length);
745 			memcpy(req->buf, hidg->report_desc, length);
746 			goto respond;
747 			break;
748 
749 		default:
750 			VDBG(cdev, "Unknown descriptor request 0x%x\n",
751 				 value >> 8);
752 			goto stall;
753 			break;
754 		}
755 		break;
756 
757 	default:
758 		VDBG(cdev, "Unknown request 0x%x\n",
759 			 ctrl->bRequest);
760 		goto stall;
761 		break;
762 	}
763 
764 stall:
765 	return -EOPNOTSUPP;
766 
767 respond:
768 	req->zero = 0;
769 	req->length = length;
770 	status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
771 	if (status < 0)
772 		ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
773 	return status;
774 }
775 
776 static void hidg_disable(struct usb_function *f)
777 {
778 	struct f_hidg *hidg = func_to_hidg(f);
779 	struct f_hidg_req_list *list, *next;
780 	unsigned long flags;
781 
782 	usb_ep_disable(hidg->in_ep);
783 
784 	if (hidg->out_ep) {
785 		usb_ep_disable(hidg->out_ep);
786 
787 		spin_lock_irqsave(&hidg->read_spinlock, flags);
788 		list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
789 			free_ep_req(hidg->out_ep, list->req);
790 			list_del(&list->list);
791 			kfree(list);
792 		}
793 		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
794 	}
795 
796 	spin_lock_irqsave(&hidg->write_spinlock, flags);
797 	if (!hidg->write_pending) {
798 		free_ep_req(hidg->in_ep, hidg->req);
799 		hidg->write_pending = 1;
800 	}
801 
802 	hidg->req = NULL;
803 	spin_unlock_irqrestore(&hidg->write_spinlock, flags);
804 }
805 
806 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
807 {
808 	struct usb_composite_dev		*cdev = f->config->cdev;
809 	struct f_hidg				*hidg = func_to_hidg(f);
810 	struct usb_request			*req_in = NULL;
811 	unsigned long				flags;
812 	int i, status = 0;
813 
814 	VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
815 
816 	if (hidg->in_ep != NULL) {
817 		/* restart endpoint */
818 		usb_ep_disable(hidg->in_ep);
819 
820 		status = config_ep_by_speed(f->config->cdev->gadget, f,
821 					    hidg->in_ep);
822 		if (status) {
823 			ERROR(cdev, "config_ep_by_speed FAILED!\n");
824 			goto fail;
825 		}
826 		status = usb_ep_enable(hidg->in_ep);
827 		if (status < 0) {
828 			ERROR(cdev, "Enable IN endpoint FAILED!\n");
829 			goto fail;
830 		}
831 		hidg->in_ep->driver_data = hidg;
832 
833 		req_in = hidg_alloc_ep_req(hidg->in_ep, hidg->report_length);
834 		if (!req_in) {
835 			status = -ENOMEM;
836 			goto disable_ep_in;
837 		}
838 	}
839 
840 	if (hidg->use_out_ep && hidg->out_ep != NULL) {
841 		/* restart endpoint */
842 		usb_ep_disable(hidg->out_ep);
843 
844 		status = config_ep_by_speed(f->config->cdev->gadget, f,
845 					    hidg->out_ep);
846 		if (status) {
847 			ERROR(cdev, "config_ep_by_speed FAILED!\n");
848 			goto free_req_in;
849 		}
850 		status = usb_ep_enable(hidg->out_ep);
851 		if (status < 0) {
852 			ERROR(cdev, "Enable OUT endpoint FAILED!\n");
853 			goto free_req_in;
854 		}
855 		hidg->out_ep->driver_data = hidg;
856 
857 		/*
858 		 * allocate a bunch of read buffers and queue them all at once.
859 		 */
860 		for (i = 0; i < hidg->qlen && status == 0; i++) {
861 			struct usb_request *req =
862 					hidg_alloc_ep_req(hidg->out_ep,
863 							  hidg->report_length);
864 			if (req) {
865 				req->complete = hidg_intout_complete;
866 				req->context  = hidg;
867 				status = usb_ep_queue(hidg->out_ep, req,
868 						      GFP_ATOMIC);
869 				if (status) {
870 					ERROR(cdev, "%s queue req --> %d\n",
871 						hidg->out_ep->name, status);
872 					free_ep_req(hidg->out_ep, req);
873 				}
874 			} else {
875 				status = -ENOMEM;
876 				goto disable_out_ep;
877 			}
878 		}
879 	}
880 
881 	if (hidg->in_ep != NULL) {
882 		spin_lock_irqsave(&hidg->write_spinlock, flags);
883 		hidg->req = req_in;
884 		hidg->write_pending = 0;
885 		spin_unlock_irqrestore(&hidg->write_spinlock, flags);
886 
887 		wake_up(&hidg->write_queue);
888 	}
889 	return 0;
890 disable_out_ep:
891 	if (hidg->out_ep)
892 		usb_ep_disable(hidg->out_ep);
893 free_req_in:
894 	if (req_in)
895 		free_ep_req(hidg->in_ep, req_in);
896 
897 disable_ep_in:
898 	if (hidg->in_ep)
899 		usb_ep_disable(hidg->in_ep);
900 
901 fail:
902 	return status;
903 }
904 
905 static const struct file_operations f_hidg_fops = {
906 	.owner		= THIS_MODULE,
907 	.open		= f_hidg_open,
908 	.release	= f_hidg_release,
909 	.write		= f_hidg_write,
910 	.read		= f_hidg_read,
911 	.poll		= f_hidg_poll,
912 	.llseek		= noop_llseek,
913 };
914 
915 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
916 {
917 	struct usb_ep		*ep;
918 	struct f_hidg		*hidg = func_to_hidg(f);
919 	struct usb_string	*us;
920 	int			status;
921 
922 	/* maybe allocate device-global string IDs, and patch descriptors */
923 	us = usb_gstrings_attach(c->cdev, ct_func_strings,
924 				 ARRAY_SIZE(ct_func_string_defs));
925 	if (IS_ERR(us))
926 		return PTR_ERR(us);
927 	hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
928 
929 	/* allocate instance-specific interface IDs, and patch descriptors */
930 	status = usb_interface_id(c, f);
931 	if (status < 0)
932 		goto fail;
933 	hidg_interface_desc.bInterfaceNumber = status;
934 
935 	/* allocate instance-specific endpoints */
936 	status = -ENODEV;
937 	ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
938 	if (!ep)
939 		goto fail;
940 	hidg->in_ep = ep;
941 
942 	hidg->out_ep = NULL;
943 	if (hidg->use_out_ep) {
944 		ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
945 		if (!ep)
946 			goto fail;
947 		hidg->out_ep = ep;
948 	}
949 
950 	/* used only if use_out_ep == 1 */
951 	hidg->set_report_buf = NULL;
952 
953 	/* set descriptor dynamic values */
954 	hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
955 	hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
956 	hidg_interface_desc.bNumEndpoints = hidg->use_out_ep ? 2 : 1;
957 	hidg->protocol = HID_REPORT_PROTOCOL;
958 	hidg->idle = 1;
959 	hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
960 	hidg_ss_in_comp_desc.wBytesPerInterval =
961 				cpu_to_le16(hidg->report_length);
962 	hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
963 	hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
964 	hidg_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
965 	hidg_ss_out_comp_desc.wBytesPerInterval =
966 				cpu_to_le16(hidg->report_length);
967 	hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
968 	hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
969 	/*
970 	 * We can use hidg_desc struct here but we should not relay
971 	 * that its content won't change after returning from this function.
972 	 */
973 	hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
974 	hidg_desc.desc[0].wDescriptorLength =
975 		cpu_to_le16(hidg->report_desc_length);
976 
977 	hidg_hs_in_ep_desc.bEndpointAddress =
978 		hidg_fs_in_ep_desc.bEndpointAddress;
979 	hidg_hs_out_ep_desc.bEndpointAddress =
980 		hidg_fs_out_ep_desc.bEndpointAddress;
981 
982 	hidg_ss_in_ep_desc.bEndpointAddress =
983 		hidg_fs_in_ep_desc.bEndpointAddress;
984 	hidg_ss_out_ep_desc.bEndpointAddress =
985 		hidg_fs_out_ep_desc.bEndpointAddress;
986 
987 	if (hidg->use_out_ep)
988 		status = usb_assign_descriptors(f,
989 			hidg_fs_descriptors_intout,
990 			hidg_hs_descriptors_intout,
991 			hidg_ss_descriptors_intout,
992 			hidg_ss_descriptors_intout);
993 	else
994 		status = usb_assign_descriptors(f,
995 			hidg_fs_descriptors_ssreport,
996 			hidg_hs_descriptors_ssreport,
997 			hidg_ss_descriptors_ssreport,
998 			hidg_ss_descriptors_ssreport);
999 
1000 	if (status)
1001 		goto fail;
1002 
1003 	spin_lock_init(&hidg->write_spinlock);
1004 	hidg->write_pending = 1;
1005 	hidg->req = NULL;
1006 	spin_lock_init(&hidg->read_spinlock);
1007 	init_waitqueue_head(&hidg->write_queue);
1008 	init_waitqueue_head(&hidg->read_queue);
1009 	INIT_LIST_HEAD(&hidg->completed_out_req);
1010 
1011 	/* create char device */
1012 	cdev_init(&hidg->cdev, &f_hidg_fops);
1013 	status = cdev_device_add(&hidg->cdev, &hidg->dev);
1014 	if (status)
1015 		goto fail_free_descs;
1016 
1017 	return 0;
1018 fail_free_descs:
1019 	usb_free_all_descriptors(f);
1020 fail:
1021 	ERROR(f->config->cdev, "hidg_bind FAILED\n");
1022 	if (hidg->req != NULL)
1023 		free_ep_req(hidg->in_ep, hidg->req);
1024 
1025 	return status;
1026 }
1027 
1028 static inline int hidg_get_minor(void)
1029 {
1030 	int ret;
1031 
1032 	ret = ida_alloc(&hidg_ida, GFP_KERNEL);
1033 	if (ret >= HIDG_MINORS) {
1034 		ida_free(&hidg_ida, ret);
1035 		ret = -ENODEV;
1036 	}
1037 
1038 	return ret;
1039 }
1040 
1041 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
1042 {
1043 	return container_of(to_config_group(item), struct f_hid_opts,
1044 			    func_inst.group);
1045 }
1046 
1047 static void hid_attr_release(struct config_item *item)
1048 {
1049 	struct f_hid_opts *opts = to_f_hid_opts(item);
1050 
1051 	usb_put_function_instance(&opts->func_inst);
1052 }
1053 
1054 static struct configfs_item_operations hidg_item_ops = {
1055 	.release	= hid_attr_release,
1056 };
1057 
1058 #define F_HID_OPT(name, prec, limit)					\
1059 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
1060 {									\
1061 	struct f_hid_opts *opts = to_f_hid_opts(item);			\
1062 	int result;							\
1063 									\
1064 	mutex_lock(&opts->lock);					\
1065 	result = sprintf(page, "%d\n", opts->name);			\
1066 	mutex_unlock(&opts->lock);					\
1067 									\
1068 	return result;							\
1069 }									\
1070 									\
1071 static ssize_t f_hid_opts_##name##_store(struct config_item *item,	\
1072 					 const char *page, size_t len)	\
1073 {									\
1074 	struct f_hid_opts *opts = to_f_hid_opts(item);			\
1075 	int ret;							\
1076 	u##prec num;							\
1077 									\
1078 	mutex_lock(&opts->lock);					\
1079 	if (opts->refcnt) {						\
1080 		ret = -EBUSY;						\
1081 		goto end;						\
1082 	}								\
1083 									\
1084 	ret = kstrtou##prec(page, 0, &num);				\
1085 	if (ret)							\
1086 		goto end;						\
1087 									\
1088 	if (num > limit) {						\
1089 		ret = -EINVAL;						\
1090 		goto end;						\
1091 	}								\
1092 	opts->name = num;						\
1093 	ret = len;							\
1094 									\
1095 end:									\
1096 	mutex_unlock(&opts->lock);					\
1097 	return ret;							\
1098 }									\
1099 									\
1100 CONFIGFS_ATTR(f_hid_opts_, name)
1101 
1102 F_HID_OPT(subclass, 8, 255);
1103 F_HID_OPT(protocol, 8, 255);
1104 F_HID_OPT(no_out_endpoint, 8, 1);
1105 F_HID_OPT(report_length, 16, 65535);
1106 
1107 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
1108 {
1109 	struct f_hid_opts *opts = to_f_hid_opts(item);
1110 	int result;
1111 
1112 	mutex_lock(&opts->lock);
1113 	result = opts->report_desc_length;
1114 	memcpy(page, opts->report_desc, opts->report_desc_length);
1115 	mutex_unlock(&opts->lock);
1116 
1117 	return result;
1118 }
1119 
1120 static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
1121 					    const char *page, size_t len)
1122 {
1123 	struct f_hid_opts *opts = to_f_hid_opts(item);
1124 	int ret = -EBUSY;
1125 	char *d;
1126 
1127 	mutex_lock(&opts->lock);
1128 
1129 	if (opts->refcnt)
1130 		goto end;
1131 	if (len > PAGE_SIZE) {
1132 		ret = -ENOSPC;
1133 		goto end;
1134 	}
1135 	d = kmemdup(page, len, GFP_KERNEL);
1136 	if (!d) {
1137 		ret = -ENOMEM;
1138 		goto end;
1139 	}
1140 	kfree(opts->report_desc);
1141 	opts->report_desc = d;
1142 	opts->report_desc_length = len;
1143 	opts->report_desc_alloc = true;
1144 	ret = len;
1145 end:
1146 	mutex_unlock(&opts->lock);
1147 	return ret;
1148 }
1149 
1150 CONFIGFS_ATTR(f_hid_opts_, report_desc);
1151 
1152 static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page)
1153 {
1154 	struct f_hid_opts *opts = to_f_hid_opts(item);
1155 
1156 	return sprintf(page, "%d:%d\n", major, opts->minor);
1157 }
1158 
1159 CONFIGFS_ATTR_RO(f_hid_opts_, dev);
1160 
1161 static struct configfs_attribute *hid_attrs[] = {
1162 	&f_hid_opts_attr_subclass,
1163 	&f_hid_opts_attr_protocol,
1164 	&f_hid_opts_attr_no_out_endpoint,
1165 	&f_hid_opts_attr_report_length,
1166 	&f_hid_opts_attr_report_desc,
1167 	&f_hid_opts_attr_dev,
1168 	NULL,
1169 };
1170 
1171 static const struct config_item_type hid_func_type = {
1172 	.ct_item_ops	= &hidg_item_ops,
1173 	.ct_attrs	= hid_attrs,
1174 	.ct_owner	= THIS_MODULE,
1175 };
1176 
1177 static inline void hidg_put_minor(int minor)
1178 {
1179 	ida_free(&hidg_ida, minor);
1180 }
1181 
1182 static void hidg_free_inst(struct usb_function_instance *f)
1183 {
1184 	struct f_hid_opts *opts;
1185 
1186 	opts = container_of(f, struct f_hid_opts, func_inst);
1187 
1188 	mutex_lock(&hidg_ida_lock);
1189 
1190 	hidg_put_minor(opts->minor);
1191 	if (ida_is_empty(&hidg_ida))
1192 		ghid_cleanup();
1193 
1194 	mutex_unlock(&hidg_ida_lock);
1195 
1196 	if (opts->report_desc_alloc)
1197 		kfree(opts->report_desc);
1198 
1199 	kfree(opts);
1200 }
1201 
1202 static struct usb_function_instance *hidg_alloc_inst(void)
1203 {
1204 	struct f_hid_opts *opts;
1205 	struct usb_function_instance *ret;
1206 	int status = 0;
1207 
1208 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1209 	if (!opts)
1210 		return ERR_PTR(-ENOMEM);
1211 	mutex_init(&opts->lock);
1212 	opts->func_inst.free_func_inst = hidg_free_inst;
1213 	ret = &opts->func_inst;
1214 
1215 	mutex_lock(&hidg_ida_lock);
1216 
1217 	if (ida_is_empty(&hidg_ida)) {
1218 		status = ghid_setup(NULL, HIDG_MINORS);
1219 		if (status)  {
1220 			ret = ERR_PTR(status);
1221 			kfree(opts);
1222 			goto unlock;
1223 		}
1224 	}
1225 
1226 	opts->minor = hidg_get_minor();
1227 	if (opts->minor < 0) {
1228 		ret = ERR_PTR(opts->minor);
1229 		kfree(opts);
1230 		if (ida_is_empty(&hidg_ida))
1231 			ghid_cleanup();
1232 		goto unlock;
1233 	}
1234 	config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
1235 
1236 unlock:
1237 	mutex_unlock(&hidg_ida_lock);
1238 	return ret;
1239 }
1240 
1241 static void hidg_free(struct usb_function *f)
1242 {
1243 	struct f_hidg *hidg;
1244 	struct f_hid_opts *opts;
1245 
1246 	hidg = func_to_hidg(f);
1247 	opts = container_of(f->fi, struct f_hid_opts, func_inst);
1248 	put_device(&hidg->dev);
1249 	mutex_lock(&opts->lock);
1250 	--opts->refcnt;
1251 	mutex_unlock(&opts->lock);
1252 }
1253 
1254 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
1255 {
1256 	struct f_hidg *hidg = func_to_hidg(f);
1257 
1258 	cdev_device_del(&hidg->cdev, &hidg->dev);
1259 
1260 	usb_free_all_descriptors(f);
1261 }
1262 
1263 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
1264 {
1265 	struct f_hidg *hidg;
1266 	struct f_hid_opts *opts;
1267 	int ret;
1268 
1269 	/* allocate and initialize one new instance */
1270 	hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
1271 	if (!hidg)
1272 		return ERR_PTR(-ENOMEM);
1273 
1274 	opts = container_of(fi, struct f_hid_opts, func_inst);
1275 
1276 	mutex_lock(&opts->lock);
1277 
1278 	device_initialize(&hidg->dev);
1279 	hidg->dev.release = hidg_release;
1280 	hidg->dev.class = &hidg_class;
1281 	hidg->dev.devt = MKDEV(major, opts->minor);
1282 	ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);
1283 	if (ret)
1284 		goto err_unlock;
1285 
1286 	hidg->bInterfaceSubClass = opts->subclass;
1287 	hidg->bInterfaceProtocol = opts->protocol;
1288 	hidg->report_length = opts->report_length;
1289 	hidg->report_desc_length = opts->report_desc_length;
1290 	if (opts->report_desc) {
1291 		hidg->report_desc = kmemdup(opts->report_desc,
1292 					    opts->report_desc_length,
1293 					    GFP_KERNEL);
1294 		if (!hidg->report_desc) {
1295 			ret = -ENOMEM;
1296 			goto err_put_device;
1297 		}
1298 	}
1299 	hidg->use_out_ep = !opts->no_out_endpoint;
1300 
1301 	++opts->refcnt;
1302 	mutex_unlock(&opts->lock);
1303 
1304 	hidg->func.name    = "hid";
1305 	hidg->func.bind    = hidg_bind;
1306 	hidg->func.unbind  = hidg_unbind;
1307 	hidg->func.set_alt = hidg_set_alt;
1308 	hidg->func.disable = hidg_disable;
1309 	hidg->func.setup   = hidg_setup;
1310 	hidg->func.free_func = hidg_free;
1311 
1312 	/* this could be made configurable at some point */
1313 	hidg->qlen	   = 4;
1314 
1315 	return &hidg->func;
1316 
1317 err_put_device:
1318 	put_device(&hidg->dev);
1319 err_unlock:
1320 	mutex_unlock(&opts->lock);
1321 	return ERR_PTR(ret);
1322 }
1323 
1324 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
1325 MODULE_LICENSE("GPL");
1326 MODULE_AUTHOR("Fabien Chouteau");
1327 
1328 int ghid_setup(struct usb_gadget *g, int count)
1329 {
1330 	int status;
1331 	dev_t dev;
1332 
1333 	status = class_register(&hidg_class);
1334 	if (status)
1335 		return status;
1336 
1337 	status = alloc_chrdev_region(&dev, 0, count, "hidg");
1338 	if (status) {
1339 		class_unregister(&hidg_class);
1340 		return status;
1341 	}
1342 
1343 	major = MAJOR(dev);
1344 	minors = count;
1345 
1346 	return 0;
1347 }
1348 
1349 void ghid_cleanup(void)
1350 {
1351 	if (major) {
1352 		unregister_chrdev_region(MKDEV(major, 0), minors);
1353 		major = minors = 0;
1354 	}
1355 
1356 	class_unregister(&hidg_class);
1357 }
1358