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  * Copyright (c) 2020 Google, Inc.
7  * Author: Andrey Konovalov <andreyknvl@gmail.com>
8  */
9 
10 #include <linux/compiler.h>
11 #include <linux/ctype.h>
12 #include <linux/debugfs.h>
13 #include <linux/delay.h>
14 #include <linux/kref.h>
15 #include <linux/miscdevice.h>
16 #include <linux/module.h>
17 #include <linux/semaphore.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/uaccess.h>
21 #include <linux/wait.h>
22 
23 #include <linux/usb.h>
24 #include <linux/usb/ch9.h>
25 #include <linux/usb/ch11.h>
26 #include <linux/usb/gadget.h>
27 
28 #include <uapi/linux/usb/raw_gadget.h>
29 
30 #define	DRIVER_DESC "USB Raw Gadget"
31 #define DRIVER_NAME "raw-gadget"
32 
33 MODULE_DESCRIPTION(DRIVER_DESC);
34 MODULE_AUTHOR("Andrey Konovalov");
35 MODULE_LICENSE("GPL");
36 
37 /*----------------------------------------------------------------------*/
38 
39 #define RAW_EVENT_QUEUE_SIZE	16
40 
41 struct raw_event_queue {
42 	/* See the comment in raw_event_queue_fetch() for locking details. */
43 	spinlock_t		lock;
44 	struct semaphore	sema;
45 	struct usb_raw_event	*events[RAW_EVENT_QUEUE_SIZE];
46 	int			size;
47 };
48 
49 static void raw_event_queue_init(struct raw_event_queue *queue)
50 {
51 	spin_lock_init(&queue->lock);
52 	sema_init(&queue->sema, 0);
53 	queue->size = 0;
54 }
55 
56 static int raw_event_queue_add(struct raw_event_queue *queue,
57 	enum usb_raw_event_type type, size_t length, const void *data)
58 {
59 	unsigned long flags;
60 	struct usb_raw_event *event;
61 
62 	spin_lock_irqsave(&queue->lock, flags);
63 	if (WARN_ON(queue->size >= RAW_EVENT_QUEUE_SIZE)) {
64 		spin_unlock_irqrestore(&queue->lock, flags);
65 		return -ENOMEM;
66 	}
67 	event = kmalloc(sizeof(*event) + length, GFP_ATOMIC);
68 	if (!event) {
69 		spin_unlock_irqrestore(&queue->lock, flags);
70 		return -ENOMEM;
71 	}
72 	event->type = type;
73 	event->length = length;
74 	if (event->length)
75 		memcpy(&event->data[0], data, length);
76 	queue->events[queue->size] = event;
77 	queue->size++;
78 	up(&queue->sema);
79 	spin_unlock_irqrestore(&queue->lock, flags);
80 	return 0;
81 }
82 
83 static struct usb_raw_event *raw_event_queue_fetch(
84 				struct raw_event_queue *queue)
85 {
86 	int ret;
87 	unsigned long flags;
88 	struct usb_raw_event *event;
89 
90 	/*
91 	 * This function can be called concurrently. We first check that
92 	 * there's at least one event queued by decrementing the semaphore,
93 	 * and then take the lock to protect queue struct fields.
94 	 */
95 	ret = down_interruptible(&queue->sema);
96 	if (ret)
97 		return ERR_PTR(ret);
98 	spin_lock_irqsave(&queue->lock, flags);
99 	/*
100 	 * queue->size must have the same value as queue->sema counter (before
101 	 * the down_interruptible() call above), so this check is a fail-safe.
102 	 */
103 	if (WARN_ON(!queue->size)) {
104 		spin_unlock_irqrestore(&queue->lock, flags);
105 		return ERR_PTR(-ENODEV);
106 	}
107 	event = queue->events[0];
108 	queue->size--;
109 	memmove(&queue->events[0], &queue->events[1],
110 			queue->size * sizeof(queue->events[0]));
111 	spin_unlock_irqrestore(&queue->lock, flags);
112 	return event;
113 }
114 
115 static void raw_event_queue_destroy(struct raw_event_queue *queue)
116 {
117 	int i;
118 
119 	for (i = 0; i < queue->size; i++)
120 		kfree(queue->events[i]);
121 	queue->size = 0;
122 }
123 
124 /*----------------------------------------------------------------------*/
125 
126 struct raw_dev;
127 
128 enum ep_state {
129 	STATE_EP_DISABLED,
130 	STATE_EP_ENABLED,
131 };
132 
133 struct raw_ep {
134 	struct raw_dev		*dev;
135 	enum ep_state		state;
136 	struct usb_ep		*ep;
137 	u8			addr;
138 	struct usb_request	*req;
139 	bool			urb_queued;
140 	bool			disabling;
141 	ssize_t			status;
142 };
143 
144 enum dev_state {
145 	STATE_DEV_INVALID = 0,
146 	STATE_DEV_OPENED,
147 	STATE_DEV_INITIALIZED,
148 	STATE_DEV_RUNNING,
149 	STATE_DEV_CLOSED,
150 	STATE_DEV_FAILED
151 };
152 
153 struct raw_dev {
154 	struct kref			count;
155 	spinlock_t			lock;
156 
157 	const char			*udc_name;
158 	struct usb_gadget_driver	driver;
159 
160 	/* Reference to misc device: */
161 	struct device			*dev;
162 
163 	/* Protected by lock: */
164 	enum dev_state			state;
165 	bool				gadget_registered;
166 	struct usb_gadget		*gadget;
167 	struct usb_request		*req;
168 	bool				ep0_in_pending;
169 	bool				ep0_out_pending;
170 	bool				ep0_urb_queued;
171 	ssize_t				ep0_status;
172 	struct raw_ep			eps[USB_RAW_EPS_NUM_MAX];
173 	int				eps_num;
174 
175 	struct completion		ep0_done;
176 	struct raw_event_queue		queue;
177 };
178 
179 static struct raw_dev *dev_new(void)
180 {
181 	struct raw_dev *dev;
182 
183 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
184 	if (!dev)
185 		return NULL;
186 	/* Matches kref_put() in raw_release(). */
187 	kref_init(&dev->count);
188 	spin_lock_init(&dev->lock);
189 	init_completion(&dev->ep0_done);
190 	raw_event_queue_init(&dev->queue);
191 	return dev;
192 }
193 
194 static void dev_free(struct kref *kref)
195 {
196 	struct raw_dev *dev = container_of(kref, struct raw_dev, count);
197 	int i;
198 
199 	kfree(dev->udc_name);
200 	kfree(dev->driver.udc_name);
201 	if (dev->req) {
202 		if (dev->ep0_urb_queued)
203 			usb_ep_dequeue(dev->gadget->ep0, dev->req);
204 		usb_ep_free_request(dev->gadget->ep0, dev->req);
205 	}
206 	raw_event_queue_destroy(&dev->queue);
207 	for (i = 0; i < dev->eps_num; i++) {
208 		if (dev->eps[i].state == STATE_EP_DISABLED)
209 			continue;
210 		usb_ep_disable(dev->eps[i].ep);
211 		usb_ep_free_request(dev->eps[i].ep, dev->eps[i].req);
212 		kfree(dev->eps[i].ep->desc);
213 		dev->eps[i].state = STATE_EP_DISABLED;
214 	}
215 	kfree(dev);
216 }
217 
218 /*----------------------------------------------------------------------*/
219 
220 static int raw_queue_event(struct raw_dev *dev,
221 	enum usb_raw_event_type type, size_t length, const void *data)
222 {
223 	int ret = 0;
224 	unsigned long flags;
225 
226 	ret = raw_event_queue_add(&dev->queue, type, length, data);
227 	if (ret < 0) {
228 		spin_lock_irqsave(&dev->lock, flags);
229 		dev->state = STATE_DEV_FAILED;
230 		spin_unlock_irqrestore(&dev->lock, flags);
231 	}
232 	return ret;
233 }
234 
235 static void gadget_ep0_complete(struct usb_ep *ep, struct usb_request *req)
236 {
237 	struct raw_dev *dev = req->context;
238 	unsigned long flags;
239 
240 	spin_lock_irqsave(&dev->lock, flags);
241 	if (req->status)
242 		dev->ep0_status = req->status;
243 	else
244 		dev->ep0_status = req->actual;
245 	if (dev->ep0_in_pending)
246 		dev->ep0_in_pending = false;
247 	else
248 		dev->ep0_out_pending = false;
249 	spin_unlock_irqrestore(&dev->lock, flags);
250 
251 	complete(&dev->ep0_done);
252 }
253 
254 static u8 get_ep_addr(const char *name)
255 {
256 	/* If the endpoint has fixed function (named as e.g. "ep12out-bulk"),
257 	 * parse the endpoint address from its name. We deliberately use
258 	 * deprecated simple_strtoul() function here, as the number isn't
259 	 * followed by '\0' nor '\n'.
260 	 */
261 	if (isdigit(name[2]))
262 		return simple_strtoul(&name[2], NULL, 10);
263 	/* Otherwise the endpoint is configurable (named as e.g. "ep-a"). */
264 	return USB_RAW_EP_ADDR_ANY;
265 }
266 
267 static int gadget_bind(struct usb_gadget *gadget,
268 			struct usb_gadget_driver *driver)
269 {
270 	int ret = 0, i = 0;
271 	struct raw_dev *dev = container_of(driver, struct raw_dev, driver);
272 	struct usb_request *req;
273 	struct usb_ep *ep;
274 	unsigned long flags;
275 
276 	if (strcmp(gadget->name, dev->udc_name) != 0)
277 		return -ENODEV;
278 
279 	set_gadget_data(gadget, dev);
280 	req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
281 	if (!req) {
282 		dev_err(&gadget->dev, "usb_ep_alloc_request failed\n");
283 		set_gadget_data(gadget, NULL);
284 		return -ENOMEM;
285 	}
286 
287 	spin_lock_irqsave(&dev->lock, flags);
288 	dev->req = req;
289 	dev->req->context = dev;
290 	dev->req->complete = gadget_ep0_complete;
291 	dev->gadget = gadget;
292 	gadget_for_each_ep(ep, dev->gadget) {
293 		dev->eps[i].ep = ep;
294 		dev->eps[i].addr = get_ep_addr(ep->name);
295 		dev->eps[i].state = STATE_EP_DISABLED;
296 		i++;
297 	}
298 	dev->eps_num = i;
299 	spin_unlock_irqrestore(&dev->lock, flags);
300 
301 	/* Matches kref_put() in gadget_unbind(). */
302 	kref_get(&dev->count);
303 
304 	ret = raw_queue_event(dev, USB_RAW_EVENT_CONNECT, 0, NULL);
305 	if (ret < 0)
306 		dev_err(&gadget->dev, "failed to queue event\n");
307 
308 	return ret;
309 }
310 
311 static void gadget_unbind(struct usb_gadget *gadget)
312 {
313 	struct raw_dev *dev = get_gadget_data(gadget);
314 
315 	set_gadget_data(gadget, NULL);
316 	/* Matches kref_get() in gadget_bind(). */
317 	kref_put(&dev->count, dev_free);
318 }
319 
320 static int gadget_setup(struct usb_gadget *gadget,
321 			const struct usb_ctrlrequest *ctrl)
322 {
323 	int ret = 0;
324 	struct raw_dev *dev = get_gadget_data(gadget);
325 	unsigned long flags;
326 
327 	spin_lock_irqsave(&dev->lock, flags);
328 	if (dev->state != STATE_DEV_RUNNING) {
329 		dev_err(&gadget->dev, "ignoring, device is not running\n");
330 		ret = -ENODEV;
331 		goto out_unlock;
332 	}
333 	if (dev->ep0_in_pending || dev->ep0_out_pending) {
334 		dev_dbg(&gadget->dev, "stalling, request already pending\n");
335 		ret = -EBUSY;
336 		goto out_unlock;
337 	}
338 	if ((ctrl->bRequestType & USB_DIR_IN) && ctrl->wLength)
339 		dev->ep0_in_pending = true;
340 	else
341 		dev->ep0_out_pending = true;
342 	spin_unlock_irqrestore(&dev->lock, flags);
343 
344 	ret = raw_queue_event(dev, USB_RAW_EVENT_CONTROL, sizeof(*ctrl), ctrl);
345 	if (ret < 0)
346 		dev_err(&gadget->dev, "failed to queue event\n");
347 	goto out;
348 
349 out_unlock:
350 	spin_unlock_irqrestore(&dev->lock, flags);
351 out:
352 	return ret;
353 }
354 
355 /* These are currently unused but present in case UDC driver requires them. */
356 static void gadget_disconnect(struct usb_gadget *gadget) { }
357 static void gadget_suspend(struct usb_gadget *gadget) { }
358 static void gadget_resume(struct usb_gadget *gadget) { }
359 static void gadget_reset(struct usb_gadget *gadget) { }
360 
361 /*----------------------------------------------------------------------*/
362 
363 static struct miscdevice raw_misc_device;
364 
365 static int raw_open(struct inode *inode, struct file *fd)
366 {
367 	struct raw_dev *dev;
368 
369 	/* Nonblocking I/O is not supported yet. */
370 	if (fd->f_flags & O_NONBLOCK)
371 		return -EINVAL;
372 
373 	dev = dev_new();
374 	if (!dev)
375 		return -ENOMEM;
376 	fd->private_data = dev;
377 	dev->state = STATE_DEV_OPENED;
378 	dev->dev = raw_misc_device.this_device;
379 	return 0;
380 }
381 
382 static int raw_release(struct inode *inode, struct file *fd)
383 {
384 	int ret = 0;
385 	struct raw_dev *dev = fd->private_data;
386 	unsigned long flags;
387 	bool unregister = false;
388 
389 	spin_lock_irqsave(&dev->lock, flags);
390 	dev->state = STATE_DEV_CLOSED;
391 	if (!dev->gadget) {
392 		spin_unlock_irqrestore(&dev->lock, flags);
393 		goto out_put;
394 	}
395 	if (dev->gadget_registered)
396 		unregister = true;
397 	dev->gadget_registered = false;
398 	spin_unlock_irqrestore(&dev->lock, flags);
399 
400 	if (unregister) {
401 		ret = usb_gadget_unregister_driver(&dev->driver);
402 		if (ret != 0)
403 			dev_err(dev->dev,
404 				"usb_gadget_unregister_driver() failed with %d\n",
405 				ret);
406 		/* Matches kref_get() in raw_ioctl_run(). */
407 		kref_put(&dev->count, dev_free);
408 	}
409 
410 out_put:
411 	/* Matches dev_new() in raw_open(). */
412 	kref_put(&dev->count, dev_free);
413 	return ret;
414 }
415 
416 /*----------------------------------------------------------------------*/
417 
418 static int raw_ioctl_init(struct raw_dev *dev, unsigned long value)
419 {
420 	int ret = 0;
421 	struct usb_raw_init arg;
422 	char *udc_driver_name;
423 	char *udc_device_name;
424 	unsigned long flags;
425 
426 	if (copy_from_user(&arg, (void __user *)value, sizeof(arg)))
427 		return -EFAULT;
428 
429 	switch (arg.speed) {
430 	case USB_SPEED_UNKNOWN:
431 		arg.speed = USB_SPEED_HIGH;
432 		break;
433 	case USB_SPEED_LOW:
434 	case USB_SPEED_FULL:
435 	case USB_SPEED_HIGH:
436 	case USB_SPEED_SUPER:
437 		break;
438 	default:
439 		return -EINVAL;
440 	}
441 
442 	udc_driver_name = kmalloc(UDC_NAME_LENGTH_MAX, GFP_KERNEL);
443 	if (!udc_driver_name)
444 		return -ENOMEM;
445 	ret = strscpy(udc_driver_name, &arg.driver_name[0],
446 				UDC_NAME_LENGTH_MAX);
447 	if (ret < 0) {
448 		kfree(udc_driver_name);
449 		return ret;
450 	}
451 	ret = 0;
452 
453 	udc_device_name = kmalloc(UDC_NAME_LENGTH_MAX, GFP_KERNEL);
454 	if (!udc_device_name) {
455 		kfree(udc_driver_name);
456 		return -ENOMEM;
457 	}
458 	ret = strscpy(udc_device_name, &arg.device_name[0],
459 				UDC_NAME_LENGTH_MAX);
460 	if (ret < 0) {
461 		kfree(udc_driver_name);
462 		kfree(udc_device_name);
463 		return ret;
464 	}
465 	ret = 0;
466 
467 	spin_lock_irqsave(&dev->lock, flags);
468 	if (dev->state != STATE_DEV_OPENED) {
469 		dev_dbg(dev->dev, "fail, device is not opened\n");
470 		kfree(udc_driver_name);
471 		kfree(udc_device_name);
472 		ret = -EINVAL;
473 		goto out_unlock;
474 	}
475 	dev->udc_name = udc_driver_name;
476 
477 	dev->driver.function = DRIVER_DESC;
478 	dev->driver.max_speed = arg.speed;
479 	dev->driver.setup = gadget_setup;
480 	dev->driver.disconnect = gadget_disconnect;
481 	dev->driver.bind = gadget_bind;
482 	dev->driver.unbind = gadget_unbind;
483 	dev->driver.suspend = gadget_suspend;
484 	dev->driver.resume = gadget_resume;
485 	dev->driver.reset = gadget_reset;
486 	dev->driver.driver.name = DRIVER_NAME;
487 	dev->driver.udc_name = udc_device_name;
488 	dev->driver.match_existing_only = 1;
489 
490 	dev->state = STATE_DEV_INITIALIZED;
491 
492 out_unlock:
493 	spin_unlock_irqrestore(&dev->lock, flags);
494 	return ret;
495 }
496 
497 static int raw_ioctl_run(struct raw_dev *dev, unsigned long value)
498 {
499 	int ret = 0;
500 	unsigned long flags;
501 
502 	if (value)
503 		return -EINVAL;
504 
505 	spin_lock_irqsave(&dev->lock, flags);
506 	if (dev->state != STATE_DEV_INITIALIZED) {
507 		dev_dbg(dev->dev, "fail, device is not initialized\n");
508 		ret = -EINVAL;
509 		goto out_unlock;
510 	}
511 	spin_unlock_irqrestore(&dev->lock, flags);
512 
513 	ret = usb_gadget_probe_driver(&dev->driver);
514 
515 	spin_lock_irqsave(&dev->lock, flags);
516 	if (ret) {
517 		dev_err(dev->dev,
518 			"fail, usb_gadget_probe_driver returned %d\n", ret);
519 		dev->state = STATE_DEV_FAILED;
520 		goto out_unlock;
521 	}
522 	dev->gadget_registered = true;
523 	dev->state = STATE_DEV_RUNNING;
524 	/* Matches kref_put() in raw_release(). */
525 	kref_get(&dev->count);
526 
527 out_unlock:
528 	spin_unlock_irqrestore(&dev->lock, flags);
529 	return ret;
530 }
531 
532 static int raw_ioctl_event_fetch(struct raw_dev *dev, unsigned long value)
533 {
534 	struct usb_raw_event arg;
535 	unsigned long flags;
536 	struct usb_raw_event *event;
537 	uint32_t length;
538 
539 	if (copy_from_user(&arg, (void __user *)value, sizeof(arg)))
540 		return -EFAULT;
541 
542 	spin_lock_irqsave(&dev->lock, flags);
543 	if (dev->state != STATE_DEV_RUNNING) {
544 		dev_dbg(dev->dev, "fail, device is not running\n");
545 		spin_unlock_irqrestore(&dev->lock, flags);
546 		return -EINVAL;
547 	}
548 	if (!dev->gadget) {
549 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
550 		spin_unlock_irqrestore(&dev->lock, flags);
551 		return -EBUSY;
552 	}
553 	spin_unlock_irqrestore(&dev->lock, flags);
554 
555 	event = raw_event_queue_fetch(&dev->queue);
556 	if (PTR_ERR(event) == -EINTR) {
557 		dev_dbg(&dev->gadget->dev, "event fetching interrupted\n");
558 		return -EINTR;
559 	}
560 	if (IS_ERR(event)) {
561 		dev_err(&dev->gadget->dev, "failed to fetch event\n");
562 		spin_lock_irqsave(&dev->lock, flags);
563 		dev->state = STATE_DEV_FAILED;
564 		spin_unlock_irqrestore(&dev->lock, flags);
565 		return -ENODEV;
566 	}
567 	length = min(arg.length, event->length);
568 	if (copy_to_user((void __user *)value, event, sizeof(*event) + length)) {
569 		kfree(event);
570 		return -EFAULT;
571 	}
572 
573 	kfree(event);
574 	return 0;
575 }
576 
577 static void *raw_alloc_io_data(struct usb_raw_ep_io *io, void __user *ptr,
578 				bool get_from_user)
579 {
580 	void *data;
581 
582 	if (copy_from_user(io, ptr, sizeof(*io)))
583 		return ERR_PTR(-EFAULT);
584 	if (io->ep >= USB_RAW_EPS_NUM_MAX)
585 		return ERR_PTR(-EINVAL);
586 	if (!usb_raw_io_flags_valid(io->flags))
587 		return ERR_PTR(-EINVAL);
588 	if (io->length > PAGE_SIZE)
589 		return ERR_PTR(-EINVAL);
590 	if (get_from_user)
591 		data = memdup_user(ptr + sizeof(*io), io->length);
592 	else {
593 		data = kmalloc(io->length, GFP_KERNEL);
594 		if (!data)
595 			data = ERR_PTR(-ENOMEM);
596 	}
597 	return data;
598 }
599 
600 static int raw_process_ep0_io(struct raw_dev *dev, struct usb_raw_ep_io *io,
601 				void *data, bool in)
602 {
603 	int ret = 0;
604 	unsigned long flags;
605 
606 	spin_lock_irqsave(&dev->lock, flags);
607 	if (dev->state != STATE_DEV_RUNNING) {
608 		dev_dbg(dev->dev, "fail, device is not running\n");
609 		ret = -EINVAL;
610 		goto out_unlock;
611 	}
612 	if (!dev->gadget) {
613 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
614 		ret = -EBUSY;
615 		goto out_unlock;
616 	}
617 	if (dev->ep0_urb_queued) {
618 		dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
619 		ret = -EBUSY;
620 		goto out_unlock;
621 	}
622 	if ((in && !dev->ep0_in_pending) ||
623 			(!in && !dev->ep0_out_pending)) {
624 		dev_dbg(&dev->gadget->dev, "fail, wrong direction\n");
625 		ret = -EBUSY;
626 		goto out_unlock;
627 	}
628 	if (WARN_ON(in && dev->ep0_out_pending)) {
629 		ret = -ENODEV;
630 		dev->state = STATE_DEV_FAILED;
631 		goto out_done;
632 	}
633 	if (WARN_ON(!in && dev->ep0_in_pending)) {
634 		ret = -ENODEV;
635 		dev->state = STATE_DEV_FAILED;
636 		goto out_done;
637 	}
638 
639 	dev->req->buf = data;
640 	dev->req->length = io->length;
641 	dev->req->zero = usb_raw_io_flags_zero(io->flags);
642 	dev->ep0_urb_queued = true;
643 	spin_unlock_irqrestore(&dev->lock, flags);
644 
645 	ret = usb_ep_queue(dev->gadget->ep0, dev->req, GFP_KERNEL);
646 	if (ret) {
647 		dev_err(&dev->gadget->dev,
648 				"fail, usb_ep_queue returned %d\n", ret);
649 		spin_lock_irqsave(&dev->lock, flags);
650 		dev->state = STATE_DEV_FAILED;
651 		goto out_done;
652 	}
653 
654 	ret = wait_for_completion_interruptible(&dev->ep0_done);
655 	if (ret) {
656 		dev_dbg(&dev->gadget->dev, "wait interrupted\n");
657 		usb_ep_dequeue(dev->gadget->ep0, dev->req);
658 		wait_for_completion(&dev->ep0_done);
659 		spin_lock_irqsave(&dev->lock, flags);
660 		goto out_done;
661 	}
662 
663 	spin_lock_irqsave(&dev->lock, flags);
664 	ret = dev->ep0_status;
665 
666 out_done:
667 	dev->ep0_urb_queued = false;
668 out_unlock:
669 	spin_unlock_irqrestore(&dev->lock, flags);
670 	return ret;
671 }
672 
673 static int raw_ioctl_ep0_write(struct raw_dev *dev, unsigned long value)
674 {
675 	int ret = 0;
676 	void *data;
677 	struct usb_raw_ep_io io;
678 
679 	data = raw_alloc_io_data(&io, (void __user *)value, true);
680 	if (IS_ERR(data))
681 		return PTR_ERR(data);
682 	ret = raw_process_ep0_io(dev, &io, data, true);
683 	kfree(data);
684 	return ret;
685 }
686 
687 static int raw_ioctl_ep0_read(struct raw_dev *dev, unsigned long value)
688 {
689 	int ret = 0;
690 	void *data;
691 	struct usb_raw_ep_io io;
692 	unsigned int length;
693 
694 	data = raw_alloc_io_data(&io, (void __user *)value, false);
695 	if (IS_ERR(data))
696 		return PTR_ERR(data);
697 	ret = raw_process_ep0_io(dev, &io, data, false);
698 	if (ret < 0)
699 		goto free;
700 
701 	length = min(io.length, (unsigned int)ret);
702 	if (copy_to_user((void __user *)(value + sizeof(io)), data, length))
703 		ret = -EFAULT;
704 	else
705 		ret = length;
706 free:
707 	kfree(data);
708 	return ret;
709 }
710 
711 static int raw_ioctl_ep0_stall(struct raw_dev *dev, unsigned long value)
712 {
713 	int ret = 0;
714 	unsigned long flags;
715 
716 	if (value)
717 		return -EINVAL;
718 	spin_lock_irqsave(&dev->lock, flags);
719 	if (dev->state != STATE_DEV_RUNNING) {
720 		dev_dbg(dev->dev, "fail, device is not running\n");
721 		ret = -EINVAL;
722 		goto out_unlock;
723 	}
724 	if (!dev->gadget) {
725 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
726 		ret = -EBUSY;
727 		goto out_unlock;
728 	}
729 	if (dev->ep0_urb_queued) {
730 		dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
731 		ret = -EBUSY;
732 		goto out_unlock;
733 	}
734 	if (!dev->ep0_in_pending && !dev->ep0_out_pending) {
735 		dev_dbg(&dev->gadget->dev, "fail, no request pending\n");
736 		ret = -EBUSY;
737 		goto out_unlock;
738 	}
739 
740 	ret = usb_ep_set_halt(dev->gadget->ep0);
741 	if (ret < 0)
742 		dev_err(&dev->gadget->dev,
743 				"fail, usb_ep_set_halt returned %d\n", ret);
744 
745 	if (dev->ep0_in_pending)
746 		dev->ep0_in_pending = false;
747 	else
748 		dev->ep0_out_pending = false;
749 
750 out_unlock:
751 	spin_unlock_irqrestore(&dev->lock, flags);
752 	return ret;
753 }
754 
755 static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
756 {
757 	int ret = 0, i;
758 	unsigned long flags;
759 	struct usb_endpoint_descriptor *desc;
760 	struct raw_ep *ep;
761 
762 	desc = memdup_user((void __user *)value, sizeof(*desc));
763 	if (IS_ERR(desc))
764 		return PTR_ERR(desc);
765 
766 	/*
767 	 * Endpoints with a maxpacket length of 0 can cause crashes in UDC
768 	 * drivers.
769 	 */
770 	if (usb_endpoint_maxp(desc) == 0) {
771 		dev_dbg(dev->dev, "fail, bad endpoint maxpacket\n");
772 		kfree(desc);
773 		return -EINVAL;
774 	}
775 
776 	spin_lock_irqsave(&dev->lock, flags);
777 	if (dev->state != STATE_DEV_RUNNING) {
778 		dev_dbg(dev->dev, "fail, device is not running\n");
779 		ret = -EINVAL;
780 		goto out_free;
781 	}
782 	if (!dev->gadget) {
783 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
784 		ret = -EBUSY;
785 		goto out_free;
786 	}
787 
788 	for (i = 0; i < dev->eps_num; i++) {
789 		ep = &dev->eps[i];
790 		if (ep->state != STATE_EP_DISABLED)
791 			continue;
792 		if (ep->addr != usb_endpoint_num(desc) &&
793 				ep->addr != USB_RAW_EP_ADDR_ANY)
794 			continue;
795 		if (!usb_gadget_ep_match_desc(dev->gadget, ep->ep, desc, NULL))
796 			continue;
797 		ep->ep->desc = desc;
798 		ret = usb_ep_enable(ep->ep);
799 		if (ret < 0) {
800 			dev_err(&dev->gadget->dev,
801 				"fail, usb_ep_enable returned %d\n", ret);
802 			goto out_free;
803 		}
804 		ep->req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC);
805 		if (!ep->req) {
806 			dev_err(&dev->gadget->dev,
807 				"fail, usb_ep_alloc_request failed\n");
808 			usb_ep_disable(ep->ep);
809 			ret = -ENOMEM;
810 			goto out_free;
811 		}
812 		ep->state = STATE_EP_ENABLED;
813 		ep->ep->driver_data = ep;
814 		ret = i;
815 		goto out_unlock;
816 	}
817 
818 	dev_dbg(&dev->gadget->dev, "fail, no gadget endpoints available\n");
819 	ret = -EBUSY;
820 
821 out_free:
822 	kfree(desc);
823 out_unlock:
824 	spin_unlock_irqrestore(&dev->lock, flags);
825 	return ret;
826 }
827 
828 static int raw_ioctl_ep_disable(struct raw_dev *dev, unsigned long value)
829 {
830 	int ret = 0, i = value;
831 	unsigned long flags;
832 
833 	spin_lock_irqsave(&dev->lock, flags);
834 	if (dev->state != STATE_DEV_RUNNING) {
835 		dev_dbg(dev->dev, "fail, device is not running\n");
836 		ret = -EINVAL;
837 		goto out_unlock;
838 	}
839 	if (!dev->gadget) {
840 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
841 		ret = -EBUSY;
842 		goto out_unlock;
843 	}
844 	if (i < 0 || i >= dev->eps_num) {
845 		dev_dbg(dev->dev, "fail, invalid endpoint\n");
846 		ret = -EBUSY;
847 		goto out_unlock;
848 	}
849 	if (dev->eps[i].state == STATE_EP_DISABLED) {
850 		dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
851 		ret = -EINVAL;
852 		goto out_unlock;
853 	}
854 	if (dev->eps[i].disabling) {
855 		dev_dbg(&dev->gadget->dev,
856 				"fail, disable already in progress\n");
857 		ret = -EINVAL;
858 		goto out_unlock;
859 	}
860 	if (dev->eps[i].urb_queued) {
861 		dev_dbg(&dev->gadget->dev,
862 				"fail, waiting for urb completion\n");
863 		ret = -EINVAL;
864 		goto out_unlock;
865 	}
866 	dev->eps[i].disabling = true;
867 	spin_unlock_irqrestore(&dev->lock, flags);
868 
869 	usb_ep_disable(dev->eps[i].ep);
870 
871 	spin_lock_irqsave(&dev->lock, flags);
872 	usb_ep_free_request(dev->eps[i].ep, dev->eps[i].req);
873 	kfree(dev->eps[i].ep->desc);
874 	dev->eps[i].state = STATE_EP_DISABLED;
875 	dev->eps[i].disabling = false;
876 
877 out_unlock:
878 	spin_unlock_irqrestore(&dev->lock, flags);
879 	return ret;
880 }
881 
882 static int raw_ioctl_ep_set_clear_halt_wedge(struct raw_dev *dev,
883 		unsigned long value, bool set, bool halt)
884 {
885 	int ret = 0, i = value;
886 	unsigned long flags;
887 
888 	spin_lock_irqsave(&dev->lock, flags);
889 	if (dev->state != STATE_DEV_RUNNING) {
890 		dev_dbg(dev->dev, "fail, device is not running\n");
891 		ret = -EINVAL;
892 		goto out_unlock;
893 	}
894 	if (!dev->gadget) {
895 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
896 		ret = -EBUSY;
897 		goto out_unlock;
898 	}
899 	if (i < 0 || i >= dev->eps_num) {
900 		dev_dbg(dev->dev, "fail, invalid endpoint\n");
901 		ret = -EBUSY;
902 		goto out_unlock;
903 	}
904 	if (dev->eps[i].state == STATE_EP_DISABLED) {
905 		dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
906 		ret = -EINVAL;
907 		goto out_unlock;
908 	}
909 	if (dev->eps[i].disabling) {
910 		dev_dbg(&dev->gadget->dev,
911 				"fail, disable is in progress\n");
912 		ret = -EINVAL;
913 		goto out_unlock;
914 	}
915 	if (dev->eps[i].urb_queued) {
916 		dev_dbg(&dev->gadget->dev,
917 				"fail, waiting for urb completion\n");
918 		ret = -EINVAL;
919 		goto out_unlock;
920 	}
921 	if (usb_endpoint_xfer_isoc(dev->eps[i].ep->desc)) {
922 		dev_dbg(&dev->gadget->dev,
923 				"fail, can't halt/wedge ISO endpoint\n");
924 		ret = -EINVAL;
925 		goto out_unlock;
926 	}
927 
928 	if (set && halt) {
929 		ret = usb_ep_set_halt(dev->eps[i].ep);
930 		if (ret < 0)
931 			dev_err(&dev->gadget->dev,
932 				"fail, usb_ep_set_halt returned %d\n", ret);
933 	} else if (!set && halt) {
934 		ret = usb_ep_clear_halt(dev->eps[i].ep);
935 		if (ret < 0)
936 			dev_err(&dev->gadget->dev,
937 				"fail, usb_ep_clear_halt returned %d\n", ret);
938 	} else if (set && !halt) {
939 		ret = usb_ep_set_wedge(dev->eps[i].ep);
940 		if (ret < 0)
941 			dev_err(&dev->gadget->dev,
942 				"fail, usb_ep_set_wedge returned %d\n", ret);
943 	}
944 
945 out_unlock:
946 	spin_unlock_irqrestore(&dev->lock, flags);
947 	return ret;
948 }
949 
950 static void gadget_ep_complete(struct usb_ep *ep, struct usb_request *req)
951 {
952 	struct raw_ep *r_ep = (struct raw_ep *)ep->driver_data;
953 	struct raw_dev *dev = r_ep->dev;
954 	unsigned long flags;
955 
956 	spin_lock_irqsave(&dev->lock, flags);
957 	if (req->status)
958 		r_ep->status = req->status;
959 	else
960 		r_ep->status = req->actual;
961 	spin_unlock_irqrestore(&dev->lock, flags);
962 
963 	complete((struct completion *)req->context);
964 }
965 
966 static int raw_process_ep_io(struct raw_dev *dev, struct usb_raw_ep_io *io,
967 				void *data, bool in)
968 {
969 	int ret = 0;
970 	unsigned long flags;
971 	struct raw_ep *ep;
972 	DECLARE_COMPLETION_ONSTACK(done);
973 
974 	spin_lock_irqsave(&dev->lock, flags);
975 	if (dev->state != STATE_DEV_RUNNING) {
976 		dev_dbg(dev->dev, "fail, device is not running\n");
977 		ret = -EINVAL;
978 		goto out_unlock;
979 	}
980 	if (!dev->gadget) {
981 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
982 		ret = -EBUSY;
983 		goto out_unlock;
984 	}
985 	if (io->ep >= dev->eps_num) {
986 		dev_dbg(&dev->gadget->dev, "fail, invalid endpoint\n");
987 		ret = -EINVAL;
988 		goto out_unlock;
989 	}
990 	ep = &dev->eps[io->ep];
991 	if (ep->state != STATE_EP_ENABLED) {
992 		dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
993 		ret = -EBUSY;
994 		goto out_unlock;
995 	}
996 	if (ep->disabling) {
997 		dev_dbg(&dev->gadget->dev,
998 				"fail, endpoint is already being disabled\n");
999 		ret = -EBUSY;
1000 		goto out_unlock;
1001 	}
1002 	if (ep->urb_queued) {
1003 		dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
1004 		ret = -EBUSY;
1005 		goto out_unlock;
1006 	}
1007 	if ((in && !ep->ep->caps.dir_in) || (!in && ep->ep->caps.dir_in)) {
1008 		dev_dbg(&dev->gadget->dev, "fail, wrong direction\n");
1009 		ret = -EINVAL;
1010 		goto out_unlock;
1011 	}
1012 
1013 	ep->dev = dev;
1014 	ep->req->context = &done;
1015 	ep->req->complete = gadget_ep_complete;
1016 	ep->req->buf = data;
1017 	ep->req->length = io->length;
1018 	ep->req->zero = usb_raw_io_flags_zero(io->flags);
1019 	ep->urb_queued = true;
1020 	spin_unlock_irqrestore(&dev->lock, flags);
1021 
1022 	ret = usb_ep_queue(ep->ep, ep->req, GFP_KERNEL);
1023 	if (ret) {
1024 		dev_err(&dev->gadget->dev,
1025 				"fail, usb_ep_queue returned %d\n", ret);
1026 		spin_lock_irqsave(&dev->lock, flags);
1027 		dev->state = STATE_DEV_FAILED;
1028 		goto out_done;
1029 	}
1030 
1031 	ret = wait_for_completion_interruptible(&done);
1032 	if (ret) {
1033 		dev_dbg(&dev->gadget->dev, "wait interrupted\n");
1034 		usb_ep_dequeue(ep->ep, ep->req);
1035 		wait_for_completion(&done);
1036 		spin_lock_irqsave(&dev->lock, flags);
1037 		goto out_done;
1038 	}
1039 
1040 	spin_lock_irqsave(&dev->lock, flags);
1041 	ret = ep->status;
1042 
1043 out_done:
1044 	ep->urb_queued = false;
1045 out_unlock:
1046 	spin_unlock_irqrestore(&dev->lock, flags);
1047 	return ret;
1048 }
1049 
1050 static int raw_ioctl_ep_write(struct raw_dev *dev, unsigned long value)
1051 {
1052 	int ret = 0;
1053 	char *data;
1054 	struct usb_raw_ep_io io;
1055 
1056 	data = raw_alloc_io_data(&io, (void __user *)value, true);
1057 	if (IS_ERR(data))
1058 		return PTR_ERR(data);
1059 	ret = raw_process_ep_io(dev, &io, data, true);
1060 	kfree(data);
1061 	return ret;
1062 }
1063 
1064 static int raw_ioctl_ep_read(struct raw_dev *dev, unsigned long value)
1065 {
1066 	int ret = 0;
1067 	char *data;
1068 	struct usb_raw_ep_io io;
1069 	unsigned int length;
1070 
1071 	data = raw_alloc_io_data(&io, (void __user *)value, false);
1072 	if (IS_ERR(data))
1073 		return PTR_ERR(data);
1074 	ret = raw_process_ep_io(dev, &io, data, false);
1075 	if (ret < 0)
1076 		goto free;
1077 
1078 	length = min(io.length, (unsigned int)ret);
1079 	if (copy_to_user((void __user *)(value + sizeof(io)), data, length))
1080 		ret = -EFAULT;
1081 	else
1082 		ret = length;
1083 free:
1084 	kfree(data);
1085 	return ret;
1086 }
1087 
1088 static int raw_ioctl_configure(struct raw_dev *dev, unsigned long value)
1089 {
1090 	int ret = 0;
1091 	unsigned long flags;
1092 
1093 	if (value)
1094 		return -EINVAL;
1095 	spin_lock_irqsave(&dev->lock, flags);
1096 	if (dev->state != STATE_DEV_RUNNING) {
1097 		dev_dbg(dev->dev, "fail, device is not running\n");
1098 		ret = -EINVAL;
1099 		goto out_unlock;
1100 	}
1101 	if (!dev->gadget) {
1102 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
1103 		ret = -EBUSY;
1104 		goto out_unlock;
1105 	}
1106 	usb_gadget_set_state(dev->gadget, USB_STATE_CONFIGURED);
1107 
1108 out_unlock:
1109 	spin_unlock_irqrestore(&dev->lock, flags);
1110 	return ret;
1111 }
1112 
1113 static int raw_ioctl_vbus_draw(struct raw_dev *dev, unsigned long value)
1114 {
1115 	int ret = 0;
1116 	unsigned long flags;
1117 
1118 	spin_lock_irqsave(&dev->lock, flags);
1119 	if (dev->state != STATE_DEV_RUNNING) {
1120 		dev_dbg(dev->dev, "fail, device is not running\n");
1121 		ret = -EINVAL;
1122 		goto out_unlock;
1123 	}
1124 	if (!dev->gadget) {
1125 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
1126 		ret = -EBUSY;
1127 		goto out_unlock;
1128 	}
1129 	usb_gadget_vbus_draw(dev->gadget, 2 * value);
1130 
1131 out_unlock:
1132 	spin_unlock_irqrestore(&dev->lock, flags);
1133 	return ret;
1134 }
1135 
1136 static void fill_ep_caps(struct usb_ep_caps *caps,
1137 				struct usb_raw_ep_caps *raw_caps)
1138 {
1139 	raw_caps->type_control = caps->type_control;
1140 	raw_caps->type_iso = caps->type_iso;
1141 	raw_caps->type_bulk = caps->type_bulk;
1142 	raw_caps->type_int = caps->type_int;
1143 	raw_caps->dir_in = caps->dir_in;
1144 	raw_caps->dir_out = caps->dir_out;
1145 }
1146 
1147 static void fill_ep_limits(struct usb_ep *ep, struct usb_raw_ep_limits *limits)
1148 {
1149 	limits->maxpacket_limit = ep->maxpacket_limit;
1150 	limits->max_streams = ep->max_streams;
1151 }
1152 
1153 static int raw_ioctl_eps_info(struct raw_dev *dev, unsigned long value)
1154 {
1155 	int ret = 0, i;
1156 	unsigned long flags;
1157 	struct usb_raw_eps_info *info;
1158 	struct raw_ep *ep;
1159 
1160 	info = kmalloc(sizeof(*info), GFP_KERNEL);
1161 	if (!info) {
1162 		ret = -ENOMEM;
1163 		goto out;
1164 	}
1165 
1166 	spin_lock_irqsave(&dev->lock, flags);
1167 	if (dev->state != STATE_DEV_RUNNING) {
1168 		dev_dbg(dev->dev, "fail, device is not running\n");
1169 		ret = -EINVAL;
1170 		spin_unlock_irqrestore(&dev->lock, flags);
1171 		goto out_free;
1172 	}
1173 	if (!dev->gadget) {
1174 		dev_dbg(dev->dev, "fail, gadget is not bound\n");
1175 		ret = -EBUSY;
1176 		spin_unlock_irqrestore(&dev->lock, flags);
1177 		goto out_free;
1178 	}
1179 
1180 	memset(info, 0, sizeof(*info));
1181 	for (i = 0; i < dev->eps_num; i++) {
1182 		ep = &dev->eps[i];
1183 		strscpy(&info->eps[i].name[0], ep->ep->name,
1184 				USB_RAW_EP_NAME_MAX);
1185 		info->eps[i].addr = ep->addr;
1186 		fill_ep_caps(&ep->ep->caps, &info->eps[i].caps);
1187 		fill_ep_limits(ep->ep, &info->eps[i].limits);
1188 	}
1189 	ret = dev->eps_num;
1190 	spin_unlock_irqrestore(&dev->lock, flags);
1191 
1192 	if (copy_to_user((void __user *)value, info, sizeof(*info)))
1193 		ret = -EFAULT;
1194 
1195 out_free:
1196 	kfree(info);
1197 out:
1198 	return ret;
1199 }
1200 
1201 static long raw_ioctl(struct file *fd, unsigned int cmd, unsigned long value)
1202 {
1203 	struct raw_dev *dev = fd->private_data;
1204 	int ret = 0;
1205 
1206 	if (!dev)
1207 		return -EBUSY;
1208 
1209 	switch (cmd) {
1210 	case USB_RAW_IOCTL_INIT:
1211 		ret = raw_ioctl_init(dev, value);
1212 		break;
1213 	case USB_RAW_IOCTL_RUN:
1214 		ret = raw_ioctl_run(dev, value);
1215 		break;
1216 	case USB_RAW_IOCTL_EVENT_FETCH:
1217 		ret = raw_ioctl_event_fetch(dev, value);
1218 		break;
1219 	case USB_RAW_IOCTL_EP0_WRITE:
1220 		ret = raw_ioctl_ep0_write(dev, value);
1221 		break;
1222 	case USB_RAW_IOCTL_EP0_READ:
1223 		ret = raw_ioctl_ep0_read(dev, value);
1224 		break;
1225 	case USB_RAW_IOCTL_EP_ENABLE:
1226 		ret = raw_ioctl_ep_enable(dev, value);
1227 		break;
1228 	case USB_RAW_IOCTL_EP_DISABLE:
1229 		ret = raw_ioctl_ep_disable(dev, value);
1230 		break;
1231 	case USB_RAW_IOCTL_EP_WRITE:
1232 		ret = raw_ioctl_ep_write(dev, value);
1233 		break;
1234 	case USB_RAW_IOCTL_EP_READ:
1235 		ret = raw_ioctl_ep_read(dev, value);
1236 		break;
1237 	case USB_RAW_IOCTL_CONFIGURE:
1238 		ret = raw_ioctl_configure(dev, value);
1239 		break;
1240 	case USB_RAW_IOCTL_VBUS_DRAW:
1241 		ret = raw_ioctl_vbus_draw(dev, value);
1242 		break;
1243 	case USB_RAW_IOCTL_EPS_INFO:
1244 		ret = raw_ioctl_eps_info(dev, value);
1245 		break;
1246 	case USB_RAW_IOCTL_EP0_STALL:
1247 		ret = raw_ioctl_ep0_stall(dev, value);
1248 		break;
1249 	case USB_RAW_IOCTL_EP_SET_HALT:
1250 		ret = raw_ioctl_ep_set_clear_halt_wedge(
1251 					dev, value, true, true);
1252 		break;
1253 	case USB_RAW_IOCTL_EP_CLEAR_HALT:
1254 		ret = raw_ioctl_ep_set_clear_halt_wedge(
1255 					dev, value, false, true);
1256 		break;
1257 	case USB_RAW_IOCTL_EP_SET_WEDGE:
1258 		ret = raw_ioctl_ep_set_clear_halt_wedge(
1259 					dev, value, true, false);
1260 		break;
1261 	default:
1262 		ret = -EINVAL;
1263 	}
1264 
1265 	return ret;
1266 }
1267 
1268 /*----------------------------------------------------------------------*/
1269 
1270 static const struct file_operations raw_fops = {
1271 	.open =			raw_open,
1272 	.unlocked_ioctl =	raw_ioctl,
1273 	.compat_ioctl =		raw_ioctl,
1274 	.release =		raw_release,
1275 	.llseek =		no_llseek,
1276 };
1277 
1278 static struct miscdevice raw_misc_device = {
1279 	.minor = MISC_DYNAMIC_MINOR,
1280 	.name = DRIVER_NAME,
1281 	.fops = &raw_fops,
1282 };
1283 
1284 module_misc_device(raw_misc_device);
1285