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