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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 
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/hid.h>
15 #include <linux/cdev.h>
16 #include <linux/mutex.h>
17 #include <linux/poll.h>
18 #include <linux/uaccess.h>
19 #include <linux/wait.h>
20 #include <linux/sched.h>
21 #include <linux/usb/g_hid.h>
22 
23 #include "u_f.h"
24 
25 static int major, minors;
26 static struct class *hidg_class;
27 
28 /*-------------------------------------------------------------------------*/
29 /*                            HID gadget struct                            */
30 
31 struct f_hidg_req_list {
32 	struct usb_request	*req;
33 	unsigned int		pos;
34 	struct list_head 	list;
35 };
36 
37 struct f_hidg {
38 	/* configuration */
39 	unsigned char			bInterfaceSubClass;
40 	unsigned char			bInterfaceProtocol;
41 	unsigned short			report_desc_length;
42 	char				*report_desc;
43 	unsigned short			report_length;
44 
45 	/* recv report */
46 	struct list_head		completed_out_req;
47 	spinlock_t			spinlock;
48 	wait_queue_head_t		read_queue;
49 	unsigned int			qlen;
50 
51 	/* send report */
52 	struct mutex			lock;
53 	bool				write_pending;
54 	wait_queue_head_t		write_queue;
55 	struct usb_request		*req;
56 
57 	int				minor;
58 	struct cdev			cdev;
59 	struct usb_function		func;
60 
61 	struct usb_ep			*in_ep;
62 	struct usb_ep			*out_ep;
63 };
64 
func_to_hidg(struct usb_function * f)65 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
66 {
67 	return container_of(f, struct f_hidg, func);
68 }
69 
70 /*-------------------------------------------------------------------------*/
71 /*                           Static descriptors                            */
72 
73 static struct usb_interface_descriptor hidg_interface_desc = {
74 	.bLength		= sizeof hidg_interface_desc,
75 	.bDescriptorType	= USB_DT_INTERFACE,
76 	/* .bInterfaceNumber	= DYNAMIC */
77 	.bAlternateSetting	= 0,
78 	.bNumEndpoints		= 2,
79 	.bInterfaceClass	= USB_CLASS_HID,
80 	/* .bInterfaceSubClass	= DYNAMIC */
81 	/* .bInterfaceProtocol	= DYNAMIC */
82 	/* .iInterface		= DYNAMIC */
83 };
84 
85 static struct hid_descriptor hidg_desc = {
86 	.bLength			= sizeof hidg_desc,
87 	.bDescriptorType		= HID_DT_HID,
88 	.bcdHID				= 0x0101,
89 	.bCountryCode			= 0x00,
90 	.bNumDescriptors		= 0x1,
91 	/*.desc[0].bDescriptorType	= DYNAMIC */
92 	/*.desc[0].wDescriptorLenght	= DYNAMIC */
93 };
94 
95 /* High-Speed Support */
96 
97 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
98 	.bLength		= USB_DT_ENDPOINT_SIZE,
99 	.bDescriptorType	= USB_DT_ENDPOINT,
100 	.bEndpointAddress	= USB_DIR_IN,
101 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
102 	/*.wMaxPacketSize	= DYNAMIC */
103 	.bInterval		= 4, /* FIXME: Add this field in the
104 				      * HID gadget configuration?
105 				      * (struct hidg_func_descriptor)
106 				      */
107 };
108 
109 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
110 	.bLength		= USB_DT_ENDPOINT_SIZE,
111 	.bDescriptorType	= USB_DT_ENDPOINT,
112 	.bEndpointAddress	= USB_DIR_OUT,
113 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
114 	/*.wMaxPacketSize	= DYNAMIC */
115 	.bInterval		= 4, /* FIXME: Add this field in the
116 				      * HID gadget configuration?
117 				      * (struct hidg_func_descriptor)
118 				      */
119 };
120 
121 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
122 	(struct usb_descriptor_header *)&hidg_interface_desc,
123 	(struct usb_descriptor_header *)&hidg_desc,
124 	(struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
125 	(struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
126 	NULL,
127 };
128 
129 /* Full-Speed Support */
130 
131 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
132 	.bLength		= USB_DT_ENDPOINT_SIZE,
133 	.bDescriptorType	= USB_DT_ENDPOINT,
134 	.bEndpointAddress	= USB_DIR_IN,
135 	.bmAttributes		= USB_ENDPOINT_XFER_INT,
136 	/*.wMaxPacketSize	= DYNAMIC */
137 	.bInterval		= 10, /* FIXME: Add this field in the
138 				       * HID gadget configuration?
139 				       * (struct hidg_func_descriptor)
140 				       */
141 };
142 
143 static struct usb_endpoint_descriptor hidg_fs_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		= 10, /* FIXME: Add this field in the
150 				       * HID gadget configuration?
151 				       * (struct hidg_func_descriptor)
152 				       */
153 };
154 
155 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
156 	(struct usb_descriptor_header *)&hidg_interface_desc,
157 	(struct usb_descriptor_header *)&hidg_desc,
158 	(struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
159 	(struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
160 	NULL,
161 };
162 
163 /*-------------------------------------------------------------------------*/
164 /*                              Char Device                                */
165 
f_hidg_read(struct file * file,char __user * buffer,size_t count,loff_t * ptr)166 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
167 			size_t count, loff_t *ptr)
168 {
169 	struct f_hidg *hidg = file->private_data;
170 	struct f_hidg_req_list *list;
171 	struct usb_request *req;
172 	unsigned long flags;
173 	int ret;
174 
175 	if (!count)
176 		return 0;
177 
178 	if (!access_ok(VERIFY_WRITE, buffer, count))
179 		return -EFAULT;
180 
181 	spin_lock_irqsave(&hidg->spinlock, flags);
182 
183 #define READ_COND (!list_empty(&hidg->completed_out_req))
184 
185 	/* wait for at least one buffer to complete */
186 	while (!READ_COND) {
187 		spin_unlock_irqrestore(&hidg->spinlock, flags);
188 		if (file->f_flags & O_NONBLOCK)
189 			return -EAGAIN;
190 
191 		if (wait_event_interruptible(hidg->read_queue, READ_COND))
192 			return -ERESTARTSYS;
193 
194 		spin_lock_irqsave(&hidg->spinlock, flags);
195 	}
196 
197 	/* pick the first one */
198 	list = list_first_entry(&hidg->completed_out_req,
199 				struct f_hidg_req_list, list);
200 	req = list->req;
201 	count = min_t(unsigned int, count, req->actual - list->pos);
202 	spin_unlock_irqrestore(&hidg->spinlock, flags);
203 
204 	/* copy to user outside spinlock */
205 	count -= copy_to_user(buffer, req->buf + list->pos, count);
206 	list->pos += count;
207 
208 	/*
209 	 * if this request is completely handled and transfered to
210 	 * userspace, remove its entry from the list and requeue it
211 	 * again. Otherwise, we will revisit it again upon the next
212 	 * call, taking into account its current read position.
213 	 */
214 	if (list->pos == req->actual) {
215 		spin_lock_irqsave(&hidg->spinlock, flags);
216 		list_del(&list->list);
217 		kfree(list);
218 		spin_unlock_irqrestore(&hidg->spinlock, flags);
219 
220 		req->length = hidg->report_length;
221 		ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
222 		if (ret < 0)
223 			return ret;
224 	}
225 
226 	return count;
227 }
228 
f_hidg_req_complete(struct usb_ep * ep,struct usb_request * req)229 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
230 {
231 	struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
232 
233 	if (req->status != 0) {
234 		ERROR(hidg->func.config->cdev,
235 			"End Point Request ERROR: %d\n", req->status);
236 	}
237 
238 	hidg->write_pending = 0;
239 	wake_up(&hidg->write_queue);
240 }
241 
f_hidg_write(struct file * file,const char __user * buffer,size_t count,loff_t * offp)242 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
243 			    size_t count, loff_t *offp)
244 {
245 	struct f_hidg *hidg  = file->private_data;
246 	ssize_t status = -ENOMEM;
247 
248 	if (!access_ok(VERIFY_READ, buffer, count))
249 		return -EFAULT;
250 
251 	mutex_lock(&hidg->lock);
252 
253 #define WRITE_COND (!hidg->write_pending)
254 
255 	/* write queue */
256 	while (!WRITE_COND) {
257 		mutex_unlock(&hidg->lock);
258 		if (file->f_flags & O_NONBLOCK)
259 			return -EAGAIN;
260 
261 		if (wait_event_interruptible_exclusive(
262 				hidg->write_queue, WRITE_COND))
263 			return -ERESTARTSYS;
264 
265 		mutex_lock(&hidg->lock);
266 	}
267 
268 	count  = min_t(unsigned, count, hidg->report_length);
269 	status = copy_from_user(hidg->req->buf, buffer, count);
270 
271 	if (status != 0) {
272 		ERROR(hidg->func.config->cdev,
273 			"copy_from_user error\n");
274 		mutex_unlock(&hidg->lock);
275 		return -EINVAL;
276 	}
277 
278 	hidg->req->status   = 0;
279 	hidg->req->zero     = 0;
280 	hidg->req->length   = count;
281 	hidg->req->complete = f_hidg_req_complete;
282 	hidg->req->context  = hidg;
283 	hidg->write_pending = 1;
284 
285 	status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
286 	if (status < 0) {
287 		ERROR(hidg->func.config->cdev,
288 			"usb_ep_queue error on int endpoint %zd\n", status);
289 		hidg->write_pending = 0;
290 		wake_up(&hidg->write_queue);
291 	} else {
292 		status = count;
293 	}
294 
295 	mutex_unlock(&hidg->lock);
296 
297 	return status;
298 }
299 
f_hidg_poll(struct file * file,poll_table * wait)300 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
301 {
302 	struct f_hidg	*hidg  = file->private_data;
303 	unsigned int	ret = 0;
304 
305 	poll_wait(file, &hidg->read_queue, wait);
306 	poll_wait(file, &hidg->write_queue, wait);
307 
308 	if (WRITE_COND)
309 		ret |= POLLOUT | POLLWRNORM;
310 
311 	if (READ_COND)
312 		ret |= POLLIN | POLLRDNORM;
313 
314 	return ret;
315 }
316 
317 #undef WRITE_COND
318 #undef READ_COND
319 
f_hidg_release(struct inode * inode,struct file * fd)320 static int f_hidg_release(struct inode *inode, struct file *fd)
321 {
322 	fd->private_data = NULL;
323 	return 0;
324 }
325 
f_hidg_open(struct inode * inode,struct file * fd)326 static int f_hidg_open(struct inode *inode, struct file *fd)
327 {
328 	struct f_hidg *hidg =
329 		container_of(inode->i_cdev, struct f_hidg, cdev);
330 
331 	fd->private_data = hidg;
332 
333 	return 0;
334 }
335 
336 /*-------------------------------------------------------------------------*/
337 /*                                usb_function                             */
338 
hidg_alloc_ep_req(struct usb_ep * ep,unsigned length)339 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
340 						    unsigned length)
341 {
342 	return alloc_ep_req(ep, length, length);
343 }
344 
hidg_set_report_complete(struct usb_ep * ep,struct usb_request * req)345 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
346 {
347 	struct f_hidg *hidg = (struct f_hidg *) req->context;
348 	struct f_hidg_req_list *req_list;
349 	unsigned long flags;
350 
351 	req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
352 	if (!req_list)
353 		return;
354 
355 	req_list->req = req;
356 
357 	spin_lock_irqsave(&hidg->spinlock, flags);
358 	list_add_tail(&req_list->list, &hidg->completed_out_req);
359 	spin_unlock_irqrestore(&hidg->spinlock, flags);
360 
361 	wake_up(&hidg->read_queue);
362 }
363 
hidg_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)364 static int hidg_setup(struct usb_function *f,
365 		const struct usb_ctrlrequest *ctrl)
366 {
367 	struct f_hidg			*hidg = func_to_hidg(f);
368 	struct usb_composite_dev	*cdev = f->config->cdev;
369 	struct usb_request		*req  = cdev->req;
370 	int status = 0;
371 	__u16 value, length;
372 
373 	value	= __le16_to_cpu(ctrl->wValue);
374 	length	= __le16_to_cpu(ctrl->wLength);
375 
376 	VDBG(cdev,
377 	     "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
378 	     __func__, ctrl->bRequestType, ctrl->bRequest, value);
379 
380 	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
381 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
382 		  | HID_REQ_GET_REPORT):
383 		VDBG(cdev, "get_report\n");
384 
385 		/* send an empty report */
386 		length = min_t(unsigned, length, hidg->report_length);
387 		memset(req->buf, 0x0, length);
388 
389 		goto respond;
390 		break;
391 
392 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
393 		  | HID_REQ_GET_PROTOCOL):
394 		VDBG(cdev, "get_protocol\n");
395 		goto stall;
396 		break;
397 
398 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
399 		  | HID_REQ_SET_REPORT):
400 		VDBG(cdev, "set_report | wLenght=%d\n", ctrl->wLength);
401 		goto stall;
402 		break;
403 
404 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
405 		  | HID_REQ_SET_PROTOCOL):
406 		VDBG(cdev, "set_protocol\n");
407 		goto stall;
408 		break;
409 
410 	case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
411 		  | USB_REQ_GET_DESCRIPTOR):
412 		switch (value >> 8) {
413 		case HID_DT_HID:
414 			VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
415 			length = min_t(unsigned short, length,
416 						   hidg_desc.bLength);
417 			memcpy(req->buf, &hidg_desc, length);
418 			goto respond;
419 			break;
420 		case HID_DT_REPORT:
421 			VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
422 			length = min_t(unsigned short, length,
423 						   hidg->report_desc_length);
424 			memcpy(req->buf, hidg->report_desc, length);
425 			goto respond;
426 			break;
427 
428 		default:
429 			VDBG(cdev, "Unknown descriptor request 0x%x\n",
430 				 value >> 8);
431 			goto stall;
432 			break;
433 		}
434 		break;
435 
436 	default:
437 		VDBG(cdev, "Unknown request 0x%x\n",
438 			 ctrl->bRequest);
439 		goto stall;
440 		break;
441 	}
442 
443 stall:
444 	return -EOPNOTSUPP;
445 
446 respond:
447 	req->zero = 0;
448 	req->length = length;
449 	status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
450 	if (status < 0)
451 		ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
452 	return status;
453 }
454 
hidg_disable(struct usb_function * f)455 static void hidg_disable(struct usb_function *f)
456 {
457 	struct f_hidg *hidg = func_to_hidg(f);
458 	struct f_hidg_req_list *list, *next;
459 
460 	usb_ep_disable(hidg->in_ep);
461 	hidg->in_ep->driver_data = NULL;
462 
463 	usb_ep_disable(hidg->out_ep);
464 	hidg->out_ep->driver_data = NULL;
465 
466 	list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
467 		list_del(&list->list);
468 		kfree(list);
469 	}
470 }
471 
hidg_set_alt(struct usb_function * f,unsigned intf,unsigned alt)472 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
473 {
474 	struct usb_composite_dev		*cdev = f->config->cdev;
475 	struct f_hidg				*hidg = func_to_hidg(f);
476 	int i, status = 0;
477 
478 	VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
479 
480 	if (hidg->in_ep != NULL) {
481 		/* restart endpoint */
482 		if (hidg->in_ep->driver_data != NULL)
483 			usb_ep_disable(hidg->in_ep);
484 
485 		status = config_ep_by_speed(f->config->cdev->gadget, f,
486 					    hidg->in_ep);
487 		if (status) {
488 			ERROR(cdev, "config_ep_by_speed FAILED!\n");
489 			goto fail;
490 		}
491 		status = usb_ep_enable(hidg->in_ep);
492 		if (status < 0) {
493 			ERROR(cdev, "Enable IN endpoint FAILED!\n");
494 			goto fail;
495 		}
496 		hidg->in_ep->driver_data = hidg;
497 	}
498 
499 
500 	if (hidg->out_ep != NULL) {
501 		/* restart endpoint */
502 		if (hidg->out_ep->driver_data != NULL)
503 			usb_ep_disable(hidg->out_ep);
504 
505 		status = config_ep_by_speed(f->config->cdev->gadget, f,
506 					    hidg->out_ep);
507 		if (status) {
508 			ERROR(cdev, "config_ep_by_speed FAILED!\n");
509 			goto fail;
510 		}
511 		status = usb_ep_enable(hidg->out_ep);
512 		if (status < 0) {
513 			ERROR(cdev, "Enable IN endpoint FAILED!\n");
514 			goto fail;
515 		}
516 		hidg->out_ep->driver_data = hidg;
517 
518 		/*
519 		 * allocate a bunch of read buffers and queue them all at once.
520 		 */
521 		for (i = 0; i < hidg->qlen && status == 0; i++) {
522 			struct usb_request *req =
523 					hidg_alloc_ep_req(hidg->out_ep,
524 							  hidg->report_length);
525 			if (req) {
526 				req->complete = hidg_set_report_complete;
527 				req->context  = hidg;
528 				status = usb_ep_queue(hidg->out_ep, req,
529 						      GFP_ATOMIC);
530 				if (status)
531 					ERROR(cdev, "%s queue req --> %d\n",
532 						hidg->out_ep->name, status);
533 			} else {
534 				usb_ep_disable(hidg->out_ep);
535 				hidg->out_ep->driver_data = NULL;
536 				status = -ENOMEM;
537 				goto fail;
538 			}
539 		}
540 	}
541 
542 fail:
543 	return status;
544 }
545 
546 const struct file_operations f_hidg_fops = {
547 	.owner		= THIS_MODULE,
548 	.open		= f_hidg_open,
549 	.release	= f_hidg_release,
550 	.write		= f_hidg_write,
551 	.read		= f_hidg_read,
552 	.poll		= f_hidg_poll,
553 	.llseek		= noop_llseek,
554 };
555 
hidg_bind(struct usb_configuration * c,struct usb_function * f)556 static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f)
557 {
558 	struct usb_ep		*ep;
559 	struct f_hidg		*hidg = func_to_hidg(f);
560 	int			status;
561 	dev_t			dev;
562 
563 	/* allocate instance-specific interface IDs, and patch descriptors */
564 	status = usb_interface_id(c, f);
565 	if (status < 0)
566 		goto fail;
567 	hidg_interface_desc.bInterfaceNumber = status;
568 
569 	/* allocate instance-specific endpoints */
570 	status = -ENODEV;
571 	ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
572 	if (!ep)
573 		goto fail;
574 	ep->driver_data = c->cdev;	/* claim */
575 	hidg->in_ep = ep;
576 
577 	ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
578 	if (!ep)
579 		goto fail;
580 	ep->driver_data = c->cdev;	/* claim */
581 	hidg->out_ep = ep;
582 
583 	/* preallocate request and buffer */
584 	status = -ENOMEM;
585 	hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
586 	if (!hidg->req)
587 		goto fail;
588 
589 	hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
590 	if (!hidg->req->buf)
591 		goto fail;
592 
593 	/* set descriptor dynamic values */
594 	hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
595 	hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
596 	hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
597 	hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
598 	hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
599 	hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
600 	hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
601 	hidg_desc.desc[0].wDescriptorLength =
602 		cpu_to_le16(hidg->report_desc_length);
603 
604 	hidg_hs_in_ep_desc.bEndpointAddress =
605 		hidg_fs_in_ep_desc.bEndpointAddress;
606 	hidg_hs_out_ep_desc.bEndpointAddress =
607 		hidg_fs_out_ep_desc.bEndpointAddress;
608 
609 	status = usb_assign_descriptors(f, hidg_fs_descriptors,
610 			hidg_hs_descriptors, NULL);
611 	if (status)
612 		goto fail;
613 
614 	mutex_init(&hidg->lock);
615 	spin_lock_init(&hidg->spinlock);
616 	init_waitqueue_head(&hidg->write_queue);
617 	init_waitqueue_head(&hidg->read_queue);
618 	INIT_LIST_HEAD(&hidg->completed_out_req);
619 
620 	/* create char device */
621 	cdev_init(&hidg->cdev, &f_hidg_fops);
622 	dev = MKDEV(major, hidg->minor);
623 	status = cdev_add(&hidg->cdev, dev, 1);
624 	if (status)
625 		goto fail_free_descs;
626 
627 	device_create(hidg_class, NULL, dev, NULL, "%s%d", "hidg", hidg->minor);
628 
629 	return 0;
630 
631 fail_free_descs:
632 	usb_free_all_descriptors(f);
633 fail:
634 	ERROR(f->config->cdev, "hidg_bind FAILED\n");
635 	if (hidg->req != NULL) {
636 		kfree(hidg->req->buf);
637 		if (hidg->in_ep != NULL)
638 			usb_ep_free_request(hidg->in_ep, hidg->req);
639 	}
640 
641 	return status;
642 }
643 
hidg_unbind(struct usb_configuration * c,struct usb_function * f)644 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
645 {
646 	struct f_hidg *hidg = func_to_hidg(f);
647 
648 	device_destroy(hidg_class, MKDEV(major, hidg->minor));
649 	cdev_del(&hidg->cdev);
650 
651 	/* disable/free request and end point */
652 	usb_ep_disable(hidg->in_ep);
653 	usb_ep_dequeue(hidg->in_ep, hidg->req);
654 	kfree(hidg->req->buf);
655 	usb_ep_free_request(hidg->in_ep, hidg->req);
656 
657 	usb_free_all_descriptors(f);
658 
659 	kfree(hidg->report_desc);
660 	kfree(hidg);
661 }
662 
663 /*-------------------------------------------------------------------------*/
664 /*                                 Strings                                 */
665 
666 #define CT_FUNC_HID_IDX	0
667 
668 static struct usb_string ct_func_string_defs[] = {
669 	[CT_FUNC_HID_IDX].s	= "HID Interface",
670 	{},			/* end of list */
671 };
672 
673 static struct usb_gadget_strings ct_func_string_table = {
674 	.language	= 0x0409,	/* en-US */
675 	.strings	= ct_func_string_defs,
676 };
677 
678 static struct usb_gadget_strings *ct_func_strings[] = {
679 	&ct_func_string_table,
680 	NULL,
681 };
682 
683 /*-------------------------------------------------------------------------*/
684 /*                             usb_configuration                           */
685 
hidg_bind_config(struct usb_configuration * c,struct hidg_func_descriptor * fdesc,int index)686 int __init hidg_bind_config(struct usb_configuration *c,
687 			    struct hidg_func_descriptor *fdesc, int index)
688 {
689 	struct f_hidg *hidg;
690 	int status;
691 
692 	if (index >= minors)
693 		return -ENOENT;
694 
695 	/* maybe allocate device-global string IDs, and patch descriptors */
696 	if (ct_func_string_defs[CT_FUNC_HID_IDX].id == 0) {
697 		status = usb_string_id(c->cdev);
698 		if (status < 0)
699 			return status;
700 		ct_func_string_defs[CT_FUNC_HID_IDX].id = status;
701 		hidg_interface_desc.iInterface = status;
702 	}
703 
704 	/* allocate and initialize one new instance */
705 	hidg = kzalloc(sizeof *hidg, GFP_KERNEL);
706 	if (!hidg)
707 		return -ENOMEM;
708 
709 	hidg->minor = index;
710 	hidg->bInterfaceSubClass = fdesc->subclass;
711 	hidg->bInterfaceProtocol = fdesc->protocol;
712 	hidg->report_length = fdesc->report_length;
713 	hidg->report_desc_length = fdesc->report_desc_length;
714 	hidg->report_desc = kmemdup(fdesc->report_desc,
715 				    fdesc->report_desc_length,
716 				    GFP_KERNEL);
717 	if (!hidg->report_desc) {
718 		kfree(hidg);
719 		return -ENOMEM;
720 	}
721 
722 	hidg->func.name    = "hid";
723 	hidg->func.strings = ct_func_strings;
724 	hidg->func.bind    = hidg_bind;
725 	hidg->func.unbind  = hidg_unbind;
726 	hidg->func.set_alt = hidg_set_alt;
727 	hidg->func.disable = hidg_disable;
728 	hidg->func.setup   = hidg_setup;
729 
730 	/* this could me made configurable at some point */
731 	hidg->qlen	   = 4;
732 
733 	status = usb_add_function(c, &hidg->func);
734 	if (status)
735 		kfree(hidg);
736 
737 	return status;
738 }
739 
ghid_setup(struct usb_gadget * g,int count)740 int __init ghid_setup(struct usb_gadget *g, int count)
741 {
742 	int status;
743 	dev_t dev;
744 
745 	hidg_class = class_create(THIS_MODULE, "hidg");
746 
747 	status = alloc_chrdev_region(&dev, 0, count, "hidg");
748 	if (!status) {
749 		major = MAJOR(dev);
750 		minors = count;
751 	}
752 
753 	return status;
754 }
755 
ghid_cleanup(void)756 void ghid_cleanup(void)
757 {
758 	if (major) {
759 		unregister_chrdev_region(MKDEV(major, 0), minors);
760 		major = minors = 0;
761 	}
762 
763 	class_destroy(hidg_class);
764 	hidg_class = NULL;
765 }
766