xref: /linux/drivers/usb/gadget/legacy/raw_gadget.c (revision 0c8a32eed1625a65798286fb73fea8710a908545)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB Raw Gadget driver.
4  * See Documentation/usb/raw-gadget.rst for more details.
5  *
6  * Andrey Konovalov <andreyknvl@gmail.com>
7  */
8 
9 #include <linux/compiler.h>
10 #include <linux/ctype.h>
11 #include <linux/debugfs.h>
12 #include <linux/delay.h>
13 #include <linux/kref.h>
14 #include <linux/miscdevice.h>
15 #include <linux/module.h>
16 #include <linux/semaphore.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/uaccess.h>
20 #include <linux/wait.h>
21 
22 #include <linux/usb.h>
23 #include <linux/usb/ch9.h>
24 #include <linux/usb/ch11.h>
25 #include <linux/usb/gadget.h>
26 
27 #include <uapi/linux/usb/raw_gadget.h>
28 
29 #define	DRIVER_DESC "USB Raw Gadget"
30 #define DRIVER_NAME "raw-gadget"
31 
32 MODULE_DESCRIPTION(DRIVER_DESC);
33 MODULE_AUTHOR("Andrey Konovalov");
34 MODULE_LICENSE("GPL");
35 
36 /*----------------------------------------------------------------------*/
37 
38 #define RAW_EVENT_QUEUE_SIZE	16
39 
40 struct raw_event_queue {
41 	/* See the comment in raw_event_queue_fetch() for locking details. */
42 	spinlock_t		lock;
43 	struct semaphore	sema;
44 	struct usb_raw_event	*events[RAW_EVENT_QUEUE_SIZE];
45 	int			size;
46 };
47 
48 static void raw_event_queue_init(struct raw_event_queue *queue)
49 {
50 	spin_lock_init(&queue->lock);
51 	sema_init(&queue->sema, 0);
52 	queue->size = 0;
53 }
54 
55 static int raw_event_queue_add(struct raw_event_queue *queue,
56 	enum usb_raw_event_type type, size_t length, const void *data)
57 {
58 	unsigned long flags;
59 	struct usb_raw_event *event;
60 
61 	spin_lock_irqsave(&queue->lock, flags);
62 	if (WARN_ON(queue->size >= RAW_EVENT_QUEUE_SIZE)) {
63 		spin_unlock_irqrestore(&queue->lock, flags);
64 		return -ENOMEM;
65 	}
66 	event = kmalloc(sizeof(*event) + length, GFP_ATOMIC);
67 	if (!event) {
68 		spin_unlock_irqrestore(&queue->lock, flags);
69 		return -ENOMEM;
70 	}
71 	event->type = type;
72 	event->length = length;
73 	if (event->length)
74 		memcpy(&event->data[0], data, length);
75 	queue->events[queue->size] = event;
76 	queue->size++;
77 	up(&queue->sema);
78 	spin_unlock_irqrestore(&queue->lock, flags);
79 	return 0;
80 }
81 
82 static struct usb_raw_event *raw_event_queue_fetch(
83 				struct raw_event_queue *queue)
84 {
85 	int ret;
86 	unsigned long flags;
87 	struct usb_raw_event *event;
88 
89 	/*
90 	 * This function can be called concurrently. We first check that
91 	 * there's at least one event queued by decrementing the semaphore,
92 	 * and then take the lock to protect queue struct fields.
93 	 */
94 	ret = down_interruptible(&queue->sema);
95 	if (ret)
96 		return ERR_PTR(ret);
97 	spin_lock_irqsave(&queue->lock, flags);
98 	/*
99 	 * queue->size must have the same value as queue->sema counter (before
100 	 * the down_interruptible() call above), so this check is a fail-safe.
101 	 */
102 	if (WARN_ON(!queue->size)) {
103 		spin_unlock_irqrestore(&queue->lock, flags);
104 		return ERR_PTR(-ENODEV);
105 	}
106 	event = queue->events[0];
107 	queue->size--;
108 	memmove(&queue->events[0], &queue->events[1],
109 			queue->size * sizeof(queue->events[0]));
110 	spin_unlock_irqrestore(&queue->lock, flags);
111 	return event;
112 }
113 
114 static void raw_event_queue_destroy(struct raw_event_queue *queue)
115 {
116 	int i;
117 
118 	for (i = 0; i < queue->size; i++)
119 		kfree(queue->events[i]);
120 	queue->size = 0;
121 }
122 
123 /*----------------------------------------------------------------------*/
124 
125 struct raw_dev;
126 
127 enum ep_state {
128 	STATE_EP_DISABLED,
129 	STATE_EP_ENABLED,
130 };
131 
132 struct raw_ep {
133 	struct raw_dev		*dev;
134 	enum ep_state		state;
135 	struct usb_ep		*ep;
136 	u8			addr;
137 	struct usb_request	*req;
138 	bool			urb_queued;
139 	bool			disabling;
140 	ssize_t			status;
141 };
142 
143 enum dev_state {
144 	STATE_DEV_INVALID = 0,
145 	STATE_DEV_OPENED,
146 	STATE_DEV_INITIALIZED,
147 	STATE_DEV_RUNNING,
148 	STATE_DEV_CLOSED,
149 	STATE_DEV_FAILED
150 };
151 
152 struct raw_dev {
153 	struct kref			count;
154 	spinlock_t			lock;
155 
156 	const char			*udc_name;
157 	struct usb_gadget_driver	driver;
158 
159 	/* Reference to misc device: */
160 	struct device			*dev;
161 
162 	/* Protected by lock: */
163 	enum dev_state			state;
164 	bool				gadget_registered;
165 	struct usb_gadget		*gadget;
166 	struct usb_request		*req;
167 	bool				ep0_in_pending;
168 	bool				ep0_out_pending;
169 	bool				ep0_urb_queued;
170 	ssize_t				ep0_status;
171 	struct raw_ep			eps[USB_RAW_EPS_NUM_MAX];
172 	int				eps_num;
173 
174 	struct completion		ep0_done;
175 	struct raw_event_queue		queue;
176 };
177 
178 static struct raw_dev *dev_new(void)
179 {
180 	struct raw_dev *dev;
181 
182 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
183 	if (!dev)
184 		return NULL;
185 	/* Matches kref_put() in raw_release(). */
186 	kref_init(&dev->count);
187 	spin_lock_init(&dev->lock);
188 	init_completion(&dev->ep0_done);
189 	raw_event_queue_init(&dev->queue);
190 	return dev;
191 }
192 
193 static void dev_free(struct kref *kref)
194 {
195 	struct raw_dev *dev = container_of(kref, struct raw_dev, count);
196 	int i;
197 
198 	kfree(dev->udc_name);
199 	kfree(dev->driver.udc_name);
200 	if (dev->req) {
201 		if (dev->ep0_urb_queued)
202 			usb_ep_dequeue(dev->gadget->ep0, dev->req);
203 		usb_ep_free_request(dev->gadget->ep0, dev->req);
204 	}
205 	raw_event_queue_destroy(&dev->queue);
206 	for (i = 0; i < dev->eps_num; i++) {
207 		if (dev->eps[i].state == STATE_EP_DISABLED)
208 			continue;
209 		usb_ep_disable(dev->eps[i].ep);
210 		usb_ep_free_request(dev->eps[i].ep, dev->eps[i].req);
211 		kfree(dev->eps[i].ep->desc);
212 		dev->eps[i].state = STATE_EP_DISABLED;
213 	}
214 	kfree(dev);
215 }
216 
217 /*----------------------------------------------------------------------*/
218 
219 static int raw_queue_event(struct raw_dev *dev,
220 	enum usb_raw_event_type type, size_t length, const void *data)
221 {
222 	int ret = 0;
223 	unsigned long flags;
224 
225 	ret = raw_event_queue_add(&dev->queue, type, length, data);
226 	if (ret < 0) {
227 		spin_lock_irqsave(&dev->lock, flags);
228 		dev->state = STATE_DEV_FAILED;
229 		spin_unlock_irqrestore(&dev->lock, flags);
230 	}
231 	return ret;
232 }
233 
234 static void gadget_ep0_complete(struct usb_ep *ep, struct usb_request *req)
235 {
236 	struct raw_dev *dev = req->context;
237 	unsigned long flags;
238 
239 	spin_lock_irqsave(&dev->lock, flags);
240 	if (req->status)
241 		dev->ep0_status = req->status;
242 	else
243 		dev->ep0_status = req->actual;
244 	if (dev->ep0_in_pending)
245 		dev->ep0_in_pending = false;
246 	else
247 		dev->ep0_out_pending = false;
248 	spin_unlock_irqrestore(&dev->lock, flags);
249 
250 	complete(&dev->ep0_done);
251 }
252 
253 static u8 get_ep_addr(const char *name)
254 {
255 	/* If the endpoint has fixed function (named as e.g. "ep12out-bulk"),
256 	 * parse the endpoint address from its name. We deliberately use
257 	 * deprecated simple_strtoul() function here, as the number isn't
258 	 * followed by '\0' nor '\n'.
259 	 */
260 	if (isdigit(name[2]))
261 		return simple_strtoul(&name[2], NULL, 10);
262 	/* Otherwise the endpoint is configurable (named as e.g. "ep-a"). */
263 	return USB_RAW_EP_ADDR_ANY;
264 }
265 
266 static int gadget_bind(struct usb_gadget *gadget,
267 			struct usb_gadget_driver *driver)
268 {
269 	int ret = 0, i = 0;
270 	struct raw_dev *dev = container_of(driver, struct raw_dev, driver);
271 	struct usb_request *req;
272 	struct usb_ep *ep;
273 	unsigned long flags;
274 
275 	if (strcmp(gadget->name, dev->udc_name) != 0)
276 		return -ENODEV;
277 
278 	set_gadget_data(gadget, dev);
279 	req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
280 	if (!req) {
281 		dev_err(&gadget->dev, "usb_ep_alloc_request failed\n");
282 		set_gadget_data(gadget, NULL);
283 		return -ENOMEM;
284 	}
285 
286 	spin_lock_irqsave(&dev->lock, flags);
287 	dev->req = req;
288 	dev->req->context = dev;
289 	dev->req->complete = gadget_ep0_complete;
290 	dev->gadget = gadget;
291 	gadget_for_each_ep(ep, dev->gadget) {
292 		dev->eps[i].ep = ep;
293 		dev->eps[i].addr = get_ep_addr(ep->name);
294 		dev->eps[i].state = STATE_EP_DISABLED;
295 		i++;
296 	}
297 	dev->eps_num = i;
298 	spin_unlock_irqrestore(&dev->lock, flags);
299 
300 	/* Matches kref_put() in gadget_unbind(). */
301 	kref_get(&dev->count);
302 
303 	ret = raw_queue_event(dev, USB_RAW_EVENT_CONNECT, 0, NULL);
304 	if (ret < 0)
305 		dev_err(&gadget->dev, "failed to queue event\n");
306 
307 	return ret;
308 }
309 
310 static void gadget_unbind(struct usb_gadget *gadget)
311 {
312 	struct raw_dev *dev = get_gadget_data(gadget);
313 
314 	set_gadget_data(gadget, NULL);
315 	/* Matches kref_get() in gadget_bind(). */
316 	kref_put(&dev->count, dev_free);
317 }
318 
319 static int gadget_setup(struct usb_gadget *gadget,
320 			const struct usb_ctrlrequest *ctrl)
321 {
322 	int ret = 0;
323 	struct raw_dev *dev = get_gadget_data(gadget);
324 	unsigned long flags;
325 
326 	spin_lock_irqsave(&dev->lock, flags);
327 	if (dev->state != STATE_DEV_RUNNING) {
328 		dev_err(&gadget->dev, "ignoring, device is not running\n");
329 		ret = -ENODEV;
330 		goto out_unlock;
331 	}
332 	if (dev->ep0_in_pending || dev->ep0_out_pending) {
333 		dev_dbg(&gadget->dev, "stalling, request already pending\n");
334 		ret = -EBUSY;
335 		goto out_unlock;
336 	}
337 	if ((ctrl->bRequestType & USB_DIR_IN) && ctrl->wLength)
338 		dev->ep0_in_pending = true;
339 	else
340 		dev->ep0_out_pending = true;
341 	spin_unlock_irqrestore(&dev->lock, flags);
342 
343 	ret = raw_queue_event(dev, USB_RAW_EVENT_CONTROL, sizeof(*ctrl), ctrl);
344 	if (ret < 0)
345 		dev_err(&gadget->dev, "failed to queue event\n");
346 	goto out;
347 
348 out_unlock:
349 	spin_unlock_irqrestore(&dev->lock, flags);
350 out:
351 	return ret;
352 }
353 
354 /* These are currently unused but present in case UDC driver requires them. */
355 static void gadget_disconnect(struct usb_gadget *gadget) { }
356 static void gadget_suspend(struct usb_gadget *gadget) { }
357 static void gadget_resume(struct usb_gadget *gadget) { }
358 static void gadget_reset(struct usb_gadget *gadget) { }
359 
360 /*----------------------------------------------------------------------*/
361 
362 static struct miscdevice raw_misc_device;
363 
364 static int raw_open(struct inode *inode, struct file *fd)
365 {
366 	struct raw_dev *dev;
367 
368 	/* Nonblocking I/O is not supported yet. */
369 	if (fd->f_flags & O_NONBLOCK)
370 		return -EINVAL;
371 
372 	dev = dev_new();
373 	if (!dev)
374 		return -ENOMEM;
375 	fd->private_data = dev;
376 	dev->state = STATE_DEV_OPENED;
377 	dev->dev = raw_misc_device.this_device;
378 	return 0;
379 }
380 
381 static int raw_release(struct inode *inode, struct file *fd)
382 {
383 	int ret = 0;
384 	struct raw_dev *dev = fd->private_data;
385 	unsigned long flags;
386 	bool unregister = false;
387 
388 	spin_lock_irqsave(&dev->lock, flags);
389 	dev->state = STATE_DEV_CLOSED;
390 	if (!dev->gadget) {
391 		spin_unlock_irqrestore(&dev->lock, flags);
392 		goto out_put;
393 	}
394 	if (dev->gadget_registered)
395 		unregister = true;
396 	dev->gadget_registered = false;
397 	spin_unlock_irqrestore(&dev->lock, flags);
398 
399 	if (unregister) {
400 		ret = usb_gadget_unregister_driver(&dev->driver);
401 		if (ret != 0)
402 			dev_err(dev->dev,
403 				"usb_gadget_unregister_driver() failed with %d\n",
404 				ret);
405 		/* Matches kref_get() in raw_ioctl_run(). */
406 		kref_put(&dev->count, dev_free);
407 	}
408 
409 out_put:
410 	/* Matches dev_new() in raw_open(). */
411 	kref_put(&dev->count, dev_free);
412 	return ret;
413 }
414 
415 /*----------------------------------------------------------------------*/
416 
417 static int raw_ioctl_init(struct raw_dev *dev, unsigned long value)
418 {
419 	int ret = 0;
420 	struct usb_raw_init arg;
421 	char *udc_driver_name;
422 	char *udc_device_name;
423 	unsigned long flags;
424 
425 	if (copy_from_user(&arg, (void __user *)value, sizeof(arg)))
426 		return -EFAULT;
427 
428 	switch (arg.speed) {
429 	case USB_SPEED_UNKNOWN:
430 		arg.speed = USB_SPEED_HIGH;
431 		break;
432 	case USB_SPEED_LOW:
433 	case USB_SPEED_FULL:
434 	case USB_SPEED_HIGH:
435 	case USB_SPEED_SUPER:
436 		break;
437 	default:
438 		return -EINVAL;
439 	}
440 
441 	udc_driver_name = kmalloc(UDC_NAME_LENGTH_MAX, GFP_KERNEL);
442 	if (!udc_driver_name)
443 		return -ENOMEM;
444 	ret = strscpy(udc_driver_name, &arg.driver_name[0],
445 				UDC_NAME_LENGTH_MAX);
446 	if (ret < 0) {
447 		kfree(udc_driver_name);
448 		return ret;
449 	}
450 	ret = 0;
451 
452 	udc_device_name = kmalloc(UDC_NAME_LENGTH_MAX, GFP_KERNEL);
453 	if (!udc_device_name) {
454 		kfree(udc_driver_name);
455 		return -ENOMEM;
456 	}
457 	ret = strscpy(udc_device_name, &arg.device_name[0],
458 				UDC_NAME_LENGTH_MAX);
459 	if (ret < 0) {
460 		kfree(udc_driver_name);
461 		kfree(udc_device_name);
462 		return ret;
463 	}
464 	ret = 0;
465 
466 	spin_lock_irqsave(&dev->lock, flags);
467 	if (dev->state != STATE_DEV_OPENED) {
468 		dev_dbg(dev->dev, "fail, device is not opened\n");
469 		kfree(udc_driver_name);
470 		kfree(udc_device_name);
471 		ret = -EINVAL;
472 		goto out_unlock;
473 	}
474 	dev->udc_name = udc_driver_name;
475 
476 	dev->driver.function = DRIVER_DESC;
477 	dev->driver.max_speed = arg.speed;
478 	dev->driver.setup = gadget_setup;
479 	dev->driver.disconnect = gadget_disconnect;
480 	dev->driver.bind = gadget_bind;
481 	dev->driver.unbind = gadget_unbind;
482 	dev->driver.suspend = gadget_suspend;
483 	dev->driver.resume = gadget_resume;
484 	dev->driver.reset = gadget_reset;
485 	dev->driver.driver.name = DRIVER_NAME;
486 	dev->driver.udc_name = udc_device_name;
487 	dev->driver.match_existing_only = 1;
488 
489 	dev->state = STATE_DEV_INITIALIZED;
490 
491 out_unlock:
492 	spin_unlock_irqrestore(&dev->lock, flags);
493 	return ret;
494 }
495 
496 static int raw_ioctl_run(struct raw_dev *dev, unsigned long value)
497 {
498 	int ret = 0;
499 	unsigned long flags;
500 
501 	if (value)
502 		return -EINVAL;
503 
504 	spin_lock_irqsave(&dev->lock, flags);
505 	if (dev->state != STATE_DEV_INITIALIZED) {
506 		dev_dbg(dev->dev, "fail, device is not initialized\n");
507 		ret = -EINVAL;
508 		goto out_unlock;
509 	}
510 	spin_unlock_irqrestore(&dev->lock, flags);
511 
512 	ret = usb_gadget_probe_driver(&dev->driver);
513 
514 	spin_lock_irqsave(&dev->lock, flags);
515 	if (ret) {
516 		dev_err(dev->dev,
517 			"fail, usb_gadget_probe_driver returned %d\n", ret);
518 		dev->state = STATE_DEV_FAILED;
519 		goto out_unlock;
520 	}
521 	dev->gadget_registered = true;
522 	dev->state = STATE_DEV_RUNNING;
523 	/* Matches kref_put() in raw_release(). */
524 	kref_get(&dev->count);
525 
526 out_unlock:
527 	spin_unlock_irqrestore(&dev->lock, flags);
528 	return ret;
529 }
530 
531 static int raw_ioctl_event_fetch(struct raw_dev *dev, unsigned long value)
532 {
533 	struct usb_raw_event arg;
534 	unsigned long flags;
535 	struct usb_raw_event *event;
536 	uint32_t length;
537 
538 	if (copy_from_user(&arg, (void __user *)value, sizeof(arg)))
539 		return -EFAULT;
540 
541 	spin_lock_irqsave(&dev->lock, flags);
542 	if (dev->state != STATE_DEV_RUNNING) {
543 		dev_dbg(dev->dev, "fail, device is not running\n");
544 		spin_unlock_irqrestore(&dev->lock, flags);
545 		return -EINVAL;
546 	}
547 	if (!dev->gadget) {
548 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
549 		spin_unlock_irqrestore(&dev->lock, flags);
550 		return -EBUSY;
551 	}
552 	spin_unlock_irqrestore(&dev->lock, flags);
553 
554 	event = raw_event_queue_fetch(&dev->queue);
555 	if (PTR_ERR(event) == -EINTR) {
556 		dev_dbg(&dev->gadget->dev, "event fetching interrupted\n");
557 		return -EINTR;
558 	}
559 	if (IS_ERR(event)) {
560 		dev_err(&dev->gadget->dev, "failed to fetch event\n");
561 		spin_lock_irqsave(&dev->lock, flags);
562 		dev->state = STATE_DEV_FAILED;
563 		spin_unlock_irqrestore(&dev->lock, flags);
564 		return -ENODEV;
565 	}
566 	length = min(arg.length, event->length);
567 	if (copy_to_user((void __user *)value, event, sizeof(*event) + length)) {
568 		kfree(event);
569 		return -EFAULT;
570 	}
571 
572 	kfree(event);
573 	return 0;
574 }
575 
576 static void *raw_alloc_io_data(struct usb_raw_ep_io *io, void __user *ptr,
577 				bool get_from_user)
578 {
579 	void *data;
580 
581 	if (copy_from_user(io, ptr, sizeof(*io)))
582 		return ERR_PTR(-EFAULT);
583 	if (io->ep >= USB_RAW_EPS_NUM_MAX)
584 		return ERR_PTR(-EINVAL);
585 	if (!usb_raw_io_flags_valid(io->flags))
586 		return ERR_PTR(-EINVAL);
587 	if (io->length > PAGE_SIZE)
588 		return ERR_PTR(-EINVAL);
589 	if (get_from_user)
590 		data = memdup_user(ptr + sizeof(*io), io->length);
591 	else {
592 		data = kmalloc(io->length, GFP_KERNEL);
593 		if (!data)
594 			data = ERR_PTR(-ENOMEM);
595 	}
596 	return data;
597 }
598 
599 static int raw_process_ep0_io(struct raw_dev *dev, struct usb_raw_ep_io *io,
600 				void *data, bool in)
601 {
602 	int ret = 0;
603 	unsigned long flags;
604 
605 	spin_lock_irqsave(&dev->lock, flags);
606 	if (dev->state != STATE_DEV_RUNNING) {
607 		dev_dbg(dev->dev, "fail, device is not running\n");
608 		ret = -EINVAL;
609 		goto out_unlock;
610 	}
611 	if (!dev->gadget) {
612 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
613 		ret = -EBUSY;
614 		goto out_unlock;
615 	}
616 	if (dev->ep0_urb_queued) {
617 		dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
618 		ret = -EBUSY;
619 		goto out_unlock;
620 	}
621 	if ((in && !dev->ep0_in_pending) ||
622 			(!in && !dev->ep0_out_pending)) {
623 		dev_dbg(&dev->gadget->dev, "fail, wrong direction\n");
624 		ret = -EBUSY;
625 		goto out_unlock;
626 	}
627 	if (WARN_ON(in && dev->ep0_out_pending)) {
628 		ret = -ENODEV;
629 		dev->state = STATE_DEV_FAILED;
630 		goto out_done;
631 	}
632 	if (WARN_ON(!in && dev->ep0_in_pending)) {
633 		ret = -ENODEV;
634 		dev->state = STATE_DEV_FAILED;
635 		goto out_done;
636 	}
637 
638 	dev->req->buf = data;
639 	dev->req->length = io->length;
640 	dev->req->zero = usb_raw_io_flags_zero(io->flags);
641 	dev->ep0_urb_queued = true;
642 	spin_unlock_irqrestore(&dev->lock, flags);
643 
644 	ret = usb_ep_queue(dev->gadget->ep0, dev->req, GFP_KERNEL);
645 	if (ret) {
646 		dev_err(&dev->gadget->dev,
647 				"fail, usb_ep_queue returned %d\n", ret);
648 		spin_lock_irqsave(&dev->lock, flags);
649 		dev->state = STATE_DEV_FAILED;
650 		goto out_done;
651 	}
652 
653 	ret = wait_for_completion_interruptible(&dev->ep0_done);
654 	if (ret) {
655 		dev_dbg(&dev->gadget->dev, "wait interrupted\n");
656 		usb_ep_dequeue(dev->gadget->ep0, dev->req);
657 		wait_for_completion(&dev->ep0_done);
658 		spin_lock_irqsave(&dev->lock, flags);
659 		goto out_done;
660 	}
661 
662 	spin_lock_irqsave(&dev->lock, flags);
663 	ret = dev->ep0_status;
664 
665 out_done:
666 	dev->ep0_urb_queued = false;
667 out_unlock:
668 	spin_unlock_irqrestore(&dev->lock, flags);
669 	return ret;
670 }
671 
672 static int raw_ioctl_ep0_write(struct raw_dev *dev, unsigned long value)
673 {
674 	int ret = 0;
675 	void *data;
676 	struct usb_raw_ep_io io;
677 
678 	data = raw_alloc_io_data(&io, (void __user *)value, true);
679 	if (IS_ERR(data))
680 		return PTR_ERR(data);
681 	ret = raw_process_ep0_io(dev, &io, data, true);
682 	kfree(data);
683 	return ret;
684 }
685 
686 static int raw_ioctl_ep0_read(struct raw_dev *dev, unsigned long value)
687 {
688 	int ret = 0;
689 	void *data;
690 	struct usb_raw_ep_io io;
691 	unsigned int length;
692 
693 	data = raw_alloc_io_data(&io, (void __user *)value, false);
694 	if (IS_ERR(data))
695 		return PTR_ERR(data);
696 	ret = raw_process_ep0_io(dev, &io, data, false);
697 	if (ret < 0)
698 		goto free;
699 
700 	length = min(io.length, (unsigned int)ret);
701 	if (copy_to_user((void __user *)(value + sizeof(io)), data, length))
702 		ret = -EFAULT;
703 	else
704 		ret = length;
705 free:
706 	kfree(data);
707 	return ret;
708 }
709 
710 static int raw_ioctl_ep0_stall(struct raw_dev *dev, unsigned long value)
711 {
712 	int ret = 0;
713 	unsigned long flags;
714 
715 	if (value)
716 		return -EINVAL;
717 	spin_lock_irqsave(&dev->lock, flags);
718 	if (dev->state != STATE_DEV_RUNNING) {
719 		dev_dbg(dev->dev, "fail, device is not running\n");
720 		ret = -EINVAL;
721 		goto out_unlock;
722 	}
723 	if (!dev->gadget) {
724 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
725 		ret = -EBUSY;
726 		goto out_unlock;
727 	}
728 	if (dev->ep0_urb_queued) {
729 		dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
730 		ret = -EBUSY;
731 		goto out_unlock;
732 	}
733 	if (!dev->ep0_in_pending && !dev->ep0_out_pending) {
734 		dev_dbg(&dev->gadget->dev, "fail, no request pending\n");
735 		ret = -EBUSY;
736 		goto out_unlock;
737 	}
738 
739 	ret = usb_ep_set_halt(dev->gadget->ep0);
740 	if (ret < 0)
741 		dev_err(&dev->gadget->dev,
742 				"fail, usb_ep_set_halt returned %d\n", ret);
743 
744 	if (dev->ep0_in_pending)
745 		dev->ep0_in_pending = false;
746 	else
747 		dev->ep0_out_pending = false;
748 
749 out_unlock:
750 	spin_unlock_irqrestore(&dev->lock, flags);
751 	return ret;
752 }
753 
754 static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
755 {
756 	int ret = 0, i;
757 	unsigned long flags;
758 	struct usb_endpoint_descriptor *desc;
759 	struct raw_ep *ep;
760 
761 	desc = memdup_user((void __user *)value, sizeof(*desc));
762 	if (IS_ERR(desc))
763 		return PTR_ERR(desc);
764 
765 	/*
766 	 * Endpoints with a maxpacket length of 0 can cause crashes in UDC
767 	 * drivers.
768 	 */
769 	if (usb_endpoint_maxp(desc) == 0) {
770 		dev_dbg(dev->dev, "fail, bad endpoint maxpacket\n");
771 		kfree(desc);
772 		return -EINVAL;
773 	}
774 
775 	spin_lock_irqsave(&dev->lock, flags);
776 	if (dev->state != STATE_DEV_RUNNING) {
777 		dev_dbg(dev->dev, "fail, device is not running\n");
778 		ret = -EINVAL;
779 		goto out_free;
780 	}
781 	if (!dev->gadget) {
782 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
783 		ret = -EBUSY;
784 		goto out_free;
785 	}
786 
787 	for (i = 0; i < dev->eps_num; i++) {
788 		ep = &dev->eps[i];
789 		if (ep->state != STATE_EP_DISABLED)
790 			continue;
791 		if (ep->addr != usb_endpoint_num(desc) &&
792 				ep->addr != USB_RAW_EP_ADDR_ANY)
793 			continue;
794 		if (!usb_gadget_ep_match_desc(dev->gadget, ep->ep, desc, NULL))
795 			continue;
796 		ep->ep->desc = desc;
797 		ret = usb_ep_enable(ep->ep);
798 		if (ret < 0) {
799 			dev_err(&dev->gadget->dev,
800 				"fail, usb_ep_enable returned %d\n", ret);
801 			goto out_free;
802 		}
803 		ep->req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC);
804 		if (!ep->req) {
805 			dev_err(&dev->gadget->dev,
806 				"fail, usb_ep_alloc_request failed\n");
807 			usb_ep_disable(ep->ep);
808 			ret = -ENOMEM;
809 			goto out_free;
810 		}
811 		ep->state = STATE_EP_ENABLED;
812 		ep->ep->driver_data = ep;
813 		ret = i;
814 		goto out_unlock;
815 	}
816 
817 	dev_dbg(&dev->gadget->dev, "fail, no gadget endpoints available\n");
818 	ret = -EBUSY;
819 
820 out_free:
821 	kfree(desc);
822 out_unlock:
823 	spin_unlock_irqrestore(&dev->lock, flags);
824 	return ret;
825 }
826 
827 static int raw_ioctl_ep_disable(struct raw_dev *dev, unsigned long value)
828 {
829 	int ret = 0, i = value;
830 	unsigned long flags;
831 
832 	spin_lock_irqsave(&dev->lock, flags);
833 	if (dev->state != STATE_DEV_RUNNING) {
834 		dev_dbg(dev->dev, "fail, device is not running\n");
835 		ret = -EINVAL;
836 		goto out_unlock;
837 	}
838 	if (!dev->gadget) {
839 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
840 		ret = -EBUSY;
841 		goto out_unlock;
842 	}
843 	if (i < 0 || i >= dev->eps_num) {
844 		dev_dbg(dev->dev, "fail, invalid endpoint\n");
845 		ret = -EBUSY;
846 		goto out_unlock;
847 	}
848 	if (dev->eps[i].state == STATE_EP_DISABLED) {
849 		dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
850 		ret = -EINVAL;
851 		goto out_unlock;
852 	}
853 	if (dev->eps[i].disabling) {
854 		dev_dbg(&dev->gadget->dev,
855 				"fail, disable already in progress\n");
856 		ret = -EINVAL;
857 		goto out_unlock;
858 	}
859 	if (dev->eps[i].urb_queued) {
860 		dev_dbg(&dev->gadget->dev,
861 				"fail, waiting for urb completion\n");
862 		ret = -EINVAL;
863 		goto out_unlock;
864 	}
865 	dev->eps[i].disabling = true;
866 	spin_unlock_irqrestore(&dev->lock, flags);
867 
868 	usb_ep_disable(dev->eps[i].ep);
869 
870 	spin_lock_irqsave(&dev->lock, flags);
871 	usb_ep_free_request(dev->eps[i].ep, dev->eps[i].req);
872 	kfree(dev->eps[i].ep->desc);
873 	dev->eps[i].state = STATE_EP_DISABLED;
874 	dev->eps[i].disabling = false;
875 
876 out_unlock:
877 	spin_unlock_irqrestore(&dev->lock, flags);
878 	return ret;
879 }
880 
881 static int raw_ioctl_ep_set_clear_halt_wedge(struct raw_dev *dev,
882 		unsigned long value, bool set, bool halt)
883 {
884 	int ret = 0, i = value;
885 	unsigned long flags;
886 
887 	spin_lock_irqsave(&dev->lock, flags);
888 	if (dev->state != STATE_DEV_RUNNING) {
889 		dev_dbg(dev->dev, "fail, device is not running\n");
890 		ret = -EINVAL;
891 		goto out_unlock;
892 	}
893 	if (!dev->gadget) {
894 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
895 		ret = -EBUSY;
896 		goto out_unlock;
897 	}
898 	if (i < 0 || i >= dev->eps_num) {
899 		dev_dbg(dev->dev, "fail, invalid endpoint\n");
900 		ret = -EBUSY;
901 		goto out_unlock;
902 	}
903 	if (dev->eps[i].state == STATE_EP_DISABLED) {
904 		dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
905 		ret = -EINVAL;
906 		goto out_unlock;
907 	}
908 	if (dev->eps[i].disabling) {
909 		dev_dbg(&dev->gadget->dev,
910 				"fail, disable is in progress\n");
911 		ret = -EINVAL;
912 		goto out_unlock;
913 	}
914 	if (dev->eps[i].urb_queued) {
915 		dev_dbg(&dev->gadget->dev,
916 				"fail, waiting for urb completion\n");
917 		ret = -EINVAL;
918 		goto out_unlock;
919 	}
920 	if (usb_endpoint_xfer_isoc(dev->eps[i].ep->desc)) {
921 		dev_dbg(&dev->gadget->dev,
922 				"fail, can't halt/wedge ISO endpoint\n");
923 		ret = -EINVAL;
924 		goto out_unlock;
925 	}
926 
927 	if (set && halt) {
928 		ret = usb_ep_set_halt(dev->eps[i].ep);
929 		if (ret < 0)
930 			dev_err(&dev->gadget->dev,
931 				"fail, usb_ep_set_halt returned %d\n", ret);
932 	} else if (!set && halt) {
933 		ret = usb_ep_clear_halt(dev->eps[i].ep);
934 		if (ret < 0)
935 			dev_err(&dev->gadget->dev,
936 				"fail, usb_ep_clear_halt returned %d\n", ret);
937 	} else if (set && !halt) {
938 		ret = usb_ep_set_wedge(dev->eps[i].ep);
939 		if (ret < 0)
940 			dev_err(&dev->gadget->dev,
941 				"fail, usb_ep_set_wedge returned %d\n", ret);
942 	}
943 
944 out_unlock:
945 	spin_unlock_irqrestore(&dev->lock, flags);
946 	return ret;
947 }
948 
949 static void gadget_ep_complete(struct usb_ep *ep, struct usb_request *req)
950 {
951 	struct raw_ep *r_ep = (struct raw_ep *)ep->driver_data;
952 	struct raw_dev *dev = r_ep->dev;
953 	unsigned long flags;
954 
955 	spin_lock_irqsave(&dev->lock, flags);
956 	if (req->status)
957 		r_ep->status = req->status;
958 	else
959 		r_ep->status = req->actual;
960 	spin_unlock_irqrestore(&dev->lock, flags);
961 
962 	complete((struct completion *)req->context);
963 }
964 
965 static int raw_process_ep_io(struct raw_dev *dev, struct usb_raw_ep_io *io,
966 				void *data, bool in)
967 {
968 	int ret = 0;
969 	unsigned long flags;
970 	struct raw_ep *ep;
971 	DECLARE_COMPLETION_ONSTACK(done);
972 
973 	spin_lock_irqsave(&dev->lock, flags);
974 	if (dev->state != STATE_DEV_RUNNING) {
975 		dev_dbg(dev->dev, "fail, device is not running\n");
976 		ret = -EINVAL;
977 		goto out_unlock;
978 	}
979 	if (!dev->gadget) {
980 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
981 		ret = -EBUSY;
982 		goto out_unlock;
983 	}
984 	if (io->ep >= dev->eps_num) {
985 		dev_dbg(&dev->gadget->dev, "fail, invalid endpoint\n");
986 		ret = -EINVAL;
987 		goto out_unlock;
988 	}
989 	ep = &dev->eps[io->ep];
990 	if (ep->state != STATE_EP_ENABLED) {
991 		dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
992 		ret = -EBUSY;
993 		goto out_unlock;
994 	}
995 	if (ep->disabling) {
996 		dev_dbg(&dev->gadget->dev,
997 				"fail, endpoint is already being disabled\n");
998 		ret = -EBUSY;
999 		goto out_unlock;
1000 	}
1001 	if (ep->urb_queued) {
1002 		dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
1003 		ret = -EBUSY;
1004 		goto out_unlock;
1005 	}
1006 	if ((in && !ep->ep->caps.dir_in) || (!in && ep->ep->caps.dir_in)) {
1007 		dev_dbg(&dev->gadget->dev, "fail, wrong direction\n");
1008 		ret = -EINVAL;
1009 		goto out_unlock;
1010 	}
1011 
1012 	ep->dev = dev;
1013 	ep->req->context = &done;
1014 	ep->req->complete = gadget_ep_complete;
1015 	ep->req->buf = data;
1016 	ep->req->length = io->length;
1017 	ep->req->zero = usb_raw_io_flags_zero(io->flags);
1018 	ep->urb_queued = true;
1019 	spin_unlock_irqrestore(&dev->lock, flags);
1020 
1021 	ret = usb_ep_queue(ep->ep, ep->req, GFP_KERNEL);
1022 	if (ret) {
1023 		dev_err(&dev->gadget->dev,
1024 				"fail, usb_ep_queue returned %d\n", ret);
1025 		spin_lock_irqsave(&dev->lock, flags);
1026 		dev->state = STATE_DEV_FAILED;
1027 		goto out_done;
1028 	}
1029 
1030 	ret = wait_for_completion_interruptible(&done);
1031 	if (ret) {
1032 		dev_dbg(&dev->gadget->dev, "wait interrupted\n");
1033 		usb_ep_dequeue(ep->ep, ep->req);
1034 		wait_for_completion(&done);
1035 		spin_lock_irqsave(&dev->lock, flags);
1036 		goto out_done;
1037 	}
1038 
1039 	spin_lock_irqsave(&dev->lock, flags);
1040 	ret = ep->status;
1041 
1042 out_done:
1043 	ep->urb_queued = false;
1044 out_unlock:
1045 	spin_unlock_irqrestore(&dev->lock, flags);
1046 	return ret;
1047 }
1048 
1049 static int raw_ioctl_ep_write(struct raw_dev *dev, unsigned long value)
1050 {
1051 	int ret = 0;
1052 	char *data;
1053 	struct usb_raw_ep_io io;
1054 
1055 	data = raw_alloc_io_data(&io, (void __user *)value, true);
1056 	if (IS_ERR(data))
1057 		return PTR_ERR(data);
1058 	ret = raw_process_ep_io(dev, &io, data, true);
1059 	kfree(data);
1060 	return ret;
1061 }
1062 
1063 static int raw_ioctl_ep_read(struct raw_dev *dev, unsigned long value)
1064 {
1065 	int ret = 0;
1066 	char *data;
1067 	struct usb_raw_ep_io io;
1068 	unsigned int length;
1069 
1070 	data = raw_alloc_io_data(&io, (void __user *)value, false);
1071 	if (IS_ERR(data))
1072 		return PTR_ERR(data);
1073 	ret = raw_process_ep_io(dev, &io, data, false);
1074 	if (ret < 0)
1075 		goto free;
1076 
1077 	length = min(io.length, (unsigned int)ret);
1078 	if (copy_to_user((void __user *)(value + sizeof(io)), data, length))
1079 		ret = -EFAULT;
1080 	else
1081 		ret = length;
1082 free:
1083 	kfree(data);
1084 	return ret;
1085 }
1086 
1087 static int raw_ioctl_configure(struct raw_dev *dev, unsigned long value)
1088 {
1089 	int ret = 0;
1090 	unsigned long flags;
1091 
1092 	if (value)
1093 		return -EINVAL;
1094 	spin_lock_irqsave(&dev->lock, flags);
1095 	if (dev->state != STATE_DEV_RUNNING) {
1096 		dev_dbg(dev->dev, "fail, device is not running\n");
1097 		ret = -EINVAL;
1098 		goto out_unlock;
1099 	}
1100 	if (!dev->gadget) {
1101 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
1102 		ret = -EBUSY;
1103 		goto out_unlock;
1104 	}
1105 	usb_gadget_set_state(dev->gadget, USB_STATE_CONFIGURED);
1106 
1107 out_unlock:
1108 	spin_unlock_irqrestore(&dev->lock, flags);
1109 	return ret;
1110 }
1111 
1112 static int raw_ioctl_vbus_draw(struct raw_dev *dev, unsigned long value)
1113 {
1114 	int ret = 0;
1115 	unsigned long flags;
1116 
1117 	spin_lock_irqsave(&dev->lock, flags);
1118 	if (dev->state != STATE_DEV_RUNNING) {
1119 		dev_dbg(dev->dev, "fail, device is not running\n");
1120 		ret = -EINVAL;
1121 		goto out_unlock;
1122 	}
1123 	if (!dev->gadget) {
1124 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
1125 		ret = -EBUSY;
1126 		goto out_unlock;
1127 	}
1128 	usb_gadget_vbus_draw(dev->gadget, 2 * value);
1129 
1130 out_unlock:
1131 	spin_unlock_irqrestore(&dev->lock, flags);
1132 	return ret;
1133 }
1134 
1135 static void fill_ep_caps(struct usb_ep_caps *caps,
1136 				struct usb_raw_ep_caps *raw_caps)
1137 {
1138 	raw_caps->type_control = caps->type_control;
1139 	raw_caps->type_iso = caps->type_iso;
1140 	raw_caps->type_bulk = caps->type_bulk;
1141 	raw_caps->type_int = caps->type_int;
1142 	raw_caps->dir_in = caps->dir_in;
1143 	raw_caps->dir_out = caps->dir_out;
1144 }
1145 
1146 static void fill_ep_limits(struct usb_ep *ep, struct usb_raw_ep_limits *limits)
1147 {
1148 	limits->maxpacket_limit = ep->maxpacket_limit;
1149 	limits->max_streams = ep->max_streams;
1150 }
1151 
1152 static int raw_ioctl_eps_info(struct raw_dev *dev, unsigned long value)
1153 {
1154 	int ret = 0, i;
1155 	unsigned long flags;
1156 	struct usb_raw_eps_info *info;
1157 	struct raw_ep *ep;
1158 
1159 	info = kmalloc(sizeof(*info), GFP_KERNEL);
1160 	if (!info) {
1161 		ret = -ENOMEM;
1162 		goto out;
1163 	}
1164 
1165 	spin_lock_irqsave(&dev->lock, flags);
1166 	if (dev->state != STATE_DEV_RUNNING) {
1167 		dev_dbg(dev->dev, "fail, device is not running\n");
1168 		ret = -EINVAL;
1169 		spin_unlock_irqrestore(&dev->lock, flags);
1170 		goto out_free;
1171 	}
1172 	if (!dev->gadget) {
1173 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
1174 		ret = -EBUSY;
1175 		spin_unlock_irqrestore(&dev->lock, flags);
1176 		goto out_free;
1177 	}
1178 
1179 	memset(info, 0, sizeof(*info));
1180 	for (i = 0; i < dev->eps_num; i++) {
1181 		ep = &dev->eps[i];
1182 		strscpy(&info->eps[i].name[0], ep->ep->name,
1183 				USB_RAW_EP_NAME_MAX);
1184 		info->eps[i].addr = ep->addr;
1185 		fill_ep_caps(&ep->ep->caps, &info->eps[i].caps);
1186 		fill_ep_limits(ep->ep, &info->eps[i].limits);
1187 	}
1188 	ret = dev->eps_num;
1189 	spin_unlock_irqrestore(&dev->lock, flags);
1190 
1191 	if (copy_to_user((void __user *)value, info, sizeof(*info)))
1192 		ret = -EFAULT;
1193 
1194 out_free:
1195 	kfree(info);
1196 out:
1197 	return ret;
1198 }
1199 
1200 static long raw_ioctl(struct file *fd, unsigned int cmd, unsigned long value)
1201 {
1202 	struct raw_dev *dev = fd->private_data;
1203 	int ret = 0;
1204 
1205 	if (!dev)
1206 		return -EBUSY;
1207 
1208 	switch (cmd) {
1209 	case USB_RAW_IOCTL_INIT:
1210 		ret = raw_ioctl_init(dev, value);
1211 		break;
1212 	case USB_RAW_IOCTL_RUN:
1213 		ret = raw_ioctl_run(dev, value);
1214 		break;
1215 	case USB_RAW_IOCTL_EVENT_FETCH:
1216 		ret = raw_ioctl_event_fetch(dev, value);
1217 		break;
1218 	case USB_RAW_IOCTL_EP0_WRITE:
1219 		ret = raw_ioctl_ep0_write(dev, value);
1220 		break;
1221 	case USB_RAW_IOCTL_EP0_READ:
1222 		ret = raw_ioctl_ep0_read(dev, value);
1223 		break;
1224 	case USB_RAW_IOCTL_EP_ENABLE:
1225 		ret = raw_ioctl_ep_enable(dev, value);
1226 		break;
1227 	case USB_RAW_IOCTL_EP_DISABLE:
1228 		ret = raw_ioctl_ep_disable(dev, value);
1229 		break;
1230 	case USB_RAW_IOCTL_EP_WRITE:
1231 		ret = raw_ioctl_ep_write(dev, value);
1232 		break;
1233 	case USB_RAW_IOCTL_EP_READ:
1234 		ret = raw_ioctl_ep_read(dev, value);
1235 		break;
1236 	case USB_RAW_IOCTL_CONFIGURE:
1237 		ret = raw_ioctl_configure(dev, value);
1238 		break;
1239 	case USB_RAW_IOCTL_VBUS_DRAW:
1240 		ret = raw_ioctl_vbus_draw(dev, value);
1241 		break;
1242 	case USB_RAW_IOCTL_EPS_INFO:
1243 		ret = raw_ioctl_eps_info(dev, value);
1244 		break;
1245 	case USB_RAW_IOCTL_EP0_STALL:
1246 		ret = raw_ioctl_ep0_stall(dev, value);
1247 		break;
1248 	case USB_RAW_IOCTL_EP_SET_HALT:
1249 		ret = raw_ioctl_ep_set_clear_halt_wedge(
1250 					dev, value, true, true);
1251 		break;
1252 	case USB_RAW_IOCTL_EP_CLEAR_HALT:
1253 		ret = raw_ioctl_ep_set_clear_halt_wedge(
1254 					dev, value, false, true);
1255 		break;
1256 	case USB_RAW_IOCTL_EP_SET_WEDGE:
1257 		ret = raw_ioctl_ep_set_clear_halt_wedge(
1258 					dev, value, true, false);
1259 		break;
1260 	default:
1261 		ret = -EINVAL;
1262 	}
1263 
1264 	return ret;
1265 }
1266 
1267 /*----------------------------------------------------------------------*/
1268 
1269 static const struct file_operations raw_fops = {
1270 	.open =			raw_open,
1271 	.unlocked_ioctl =	raw_ioctl,
1272 	.compat_ioctl =		raw_ioctl,
1273 	.release =		raw_release,
1274 	.llseek =		no_llseek,
1275 };
1276 
1277 static struct miscdevice raw_misc_device = {
1278 	.minor = MISC_DYNAMIC_MINOR,
1279 	.name = DRIVER_NAME,
1280 	.fops = &raw_fops,
1281 };
1282 
1283 module_misc_device(raw_misc_device);
1284