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/idr.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
33MODULE_DESCRIPTION(DRIVER_DESC);
34MODULE_AUTHOR("Andrey Konovalov");
35MODULE_LICENSE("GPL");
36
37/*----------------------------------------------------------------------*/
38
39static DEFINE_IDA(driver_id_numbers);
40#define DRIVER_DRIVER_NAME_LENGTH_MAX	32
41
42#define RAW_EVENT_QUEUE_SIZE	16
43
44struct raw_event_queue {
45	/* See the comment in raw_event_queue_fetch() for locking details. */
46	spinlock_t		lock;
47	struct semaphore	sema;
48	struct usb_raw_event	*events[RAW_EVENT_QUEUE_SIZE];
49	int			size;
50};
51
52static void raw_event_queue_init(struct raw_event_queue *queue)
53{
54	spin_lock_init(&queue->lock);
55	sema_init(&queue->sema, 0);
56	queue->size = 0;
57}
58
59static int raw_event_queue_add(struct raw_event_queue *queue,
60	enum usb_raw_event_type type, size_t length, const void *data)
61{
62	unsigned long flags;
63	struct usb_raw_event *event;
64
65	spin_lock_irqsave(&queue->lock, flags);
66	if (WARN_ON(queue->size >= RAW_EVENT_QUEUE_SIZE)) {
67		spin_unlock_irqrestore(&queue->lock, flags);
68		return -ENOMEM;
69	}
70	event = kmalloc(sizeof(*event) + length, GFP_ATOMIC);
71	if (!event) {
72		spin_unlock_irqrestore(&queue->lock, flags);
73		return -ENOMEM;
74	}
75	event->type = type;
76	event->length = length;
77	if (event->length)
78		memcpy(&event->data[0], data, length);
79	queue->events[queue->size] = event;
80	queue->size++;
81	up(&queue->sema);
82	spin_unlock_irqrestore(&queue->lock, flags);
83	return 0;
84}
85
86static struct usb_raw_event *raw_event_queue_fetch(
87				struct raw_event_queue *queue)
88{
89	int ret;
90	unsigned long flags;
91	struct usb_raw_event *event;
92
93	/*
94	 * This function can be called concurrently. We first check that
95	 * there's at least one event queued by decrementing the semaphore,
96	 * and then take the lock to protect queue struct fields.
97	 */
98	ret = down_interruptible(&queue->sema);
99	if (ret)
100		return ERR_PTR(ret);
101	spin_lock_irqsave(&queue->lock, flags);
102	/*
103	 * queue->size must have the same value as queue->sema counter (before
104	 * the down_interruptible() call above), so this check is a fail-safe.
105	 */
106	if (WARN_ON(!queue->size)) {
107		spin_unlock_irqrestore(&queue->lock, flags);
108		return ERR_PTR(-ENODEV);
109	}
110	event = queue->events[0];
111	queue->size--;
112	memmove(&queue->events[0], &queue->events[1],
113			queue->size * sizeof(queue->events[0]));
114	spin_unlock_irqrestore(&queue->lock, flags);
115	return event;
116}
117
118static void raw_event_queue_destroy(struct raw_event_queue *queue)
119{
120	int i;
121
122	for (i = 0; i < queue->size; i++)
123		kfree(queue->events[i]);
124	queue->size = 0;
125}
126
127/*----------------------------------------------------------------------*/
128
129struct raw_dev;
130
131enum ep_state {
132	STATE_EP_DISABLED,
133	STATE_EP_ENABLED,
134};
135
136struct raw_ep {
137	struct raw_dev		*dev;
138	enum ep_state		state;
139	struct usb_ep		*ep;
140	u8			addr;
141	struct usb_request	*req;
142	bool			urb_queued;
143	bool			disabling;
144	ssize_t			status;
145};
146
147enum dev_state {
148	STATE_DEV_INVALID = 0,
149	STATE_DEV_OPENED,
150	STATE_DEV_INITIALIZED,
151	STATE_DEV_REGISTERING,
152	STATE_DEV_RUNNING,
153	STATE_DEV_CLOSED,
154	STATE_DEV_FAILED
155};
156
157struct raw_dev {
158	struct kref			count;
159	spinlock_t			lock;
160
161	const char			*udc_name;
162	struct usb_gadget_driver	driver;
163
164	/* Reference to misc device: */
165	struct device			*dev;
166
167	/* Make driver names unique */
168	int				driver_id_number;
169
170	/* Protected by lock: */
171	enum dev_state			state;
172	bool				gadget_registered;
173	struct usb_gadget		*gadget;
174	struct usb_request		*req;
175	bool				ep0_in_pending;
176	bool				ep0_out_pending;
177	bool				ep0_urb_queued;
178	ssize_t				ep0_status;
179	struct raw_ep			eps[USB_RAW_EPS_NUM_MAX];
180	int				eps_num;
181
182	struct completion		ep0_done;
183	struct raw_event_queue		queue;
184};
185
186static struct raw_dev *dev_new(void)
187{
188	struct raw_dev *dev;
189
190	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
191	if (!dev)
192		return NULL;
193	/* Matches kref_put() in raw_release(). */
194	kref_init(&dev->count);
195	spin_lock_init(&dev->lock);
196	init_completion(&dev->ep0_done);
197	raw_event_queue_init(&dev->queue);
198	dev->driver_id_number = -1;
199	return dev;
200}
201
202static void dev_free(struct kref *kref)
203{
204	struct raw_dev *dev = container_of(kref, struct raw_dev, count);
205	int i;
206
207	kfree(dev->udc_name);
208	kfree(dev->driver.udc_name);
209	kfree(dev->driver.driver.name);
210	if (dev->driver_id_number >= 0)
211		ida_free(&driver_id_numbers, dev->driver_id_number);
212	if (dev->req) {
213		if (dev->ep0_urb_queued)
214			usb_ep_dequeue(dev->gadget->ep0, dev->req);
215		usb_ep_free_request(dev->gadget->ep0, dev->req);
216	}
217	raw_event_queue_destroy(&dev->queue);
218	for (i = 0; i < dev->eps_num; i++) {
219		if (dev->eps[i].state == STATE_EP_DISABLED)
220			continue;
221		usb_ep_disable(dev->eps[i].ep);
222		usb_ep_free_request(dev->eps[i].ep, dev->eps[i].req);
223		kfree(dev->eps[i].ep->desc);
224		dev->eps[i].state = STATE_EP_DISABLED;
225	}
226	kfree(dev);
227}
228
229/*----------------------------------------------------------------------*/
230
231static int raw_queue_event(struct raw_dev *dev,
232	enum usb_raw_event_type type, size_t length, const void *data)
233{
234	int ret = 0;
235	unsigned long flags;
236
237	ret = raw_event_queue_add(&dev->queue, type, length, data);
238	if (ret < 0) {
239		spin_lock_irqsave(&dev->lock, flags);
240		dev->state = STATE_DEV_FAILED;
241		spin_unlock_irqrestore(&dev->lock, flags);
242	}
243	return ret;
244}
245
246static void gadget_ep0_complete(struct usb_ep *ep, struct usb_request *req)
247{
248	struct raw_dev *dev = req->context;
249	unsigned long flags;
250
251	spin_lock_irqsave(&dev->lock, flags);
252	if (req->status)
253		dev->ep0_status = req->status;
254	else
255		dev->ep0_status = req->actual;
256	if (dev->ep0_in_pending)
257		dev->ep0_in_pending = false;
258	else
259		dev->ep0_out_pending = false;
260	spin_unlock_irqrestore(&dev->lock, flags);
261
262	complete(&dev->ep0_done);
263}
264
265static u8 get_ep_addr(const char *name)
266{
267	/* If the endpoint has fixed function (named as e.g. "ep12out-bulk"),
268	 * parse the endpoint address from its name. We deliberately use
269	 * deprecated simple_strtoul() function here, as the number isn't
270	 * followed by '\0' nor '\n'.
271	 */
272	if (isdigit(name[2]))
273		return simple_strtoul(&name[2], NULL, 10);
274	/* Otherwise the endpoint is configurable (named as e.g. "ep-a"). */
275	return USB_RAW_EP_ADDR_ANY;
276}
277
278static int gadget_bind(struct usb_gadget *gadget,
279			struct usb_gadget_driver *driver)
280{
281	int ret = 0, i = 0;
282	struct raw_dev *dev = container_of(driver, struct raw_dev, driver);
283	struct usb_request *req;
284	struct usb_ep *ep;
285	unsigned long flags;
286
287	if (strcmp(gadget->name, dev->udc_name) != 0)
288		return -ENODEV;
289
290	set_gadget_data(gadget, dev);
291	req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
292	if (!req) {
293		dev_err(&gadget->dev, "usb_ep_alloc_request failed\n");
294		set_gadget_data(gadget, NULL);
295		return -ENOMEM;
296	}
297
298	spin_lock_irqsave(&dev->lock, flags);
299	dev->req = req;
300	dev->req->context = dev;
301	dev->req->complete = gadget_ep0_complete;
302	dev->gadget = gadget;
303	gadget_for_each_ep(ep, dev->gadget) {
304		dev->eps[i].ep = ep;
305		dev->eps[i].addr = get_ep_addr(ep->name);
306		dev->eps[i].state = STATE_EP_DISABLED;
307		i++;
308	}
309	dev->eps_num = i;
310	spin_unlock_irqrestore(&dev->lock, flags);
311
312	ret = raw_queue_event(dev, USB_RAW_EVENT_CONNECT, 0, NULL);
313	if (ret < 0) {
314		dev_err(&gadget->dev, "failed to queue event\n");
315		set_gadget_data(gadget, NULL);
316		return ret;
317	}
318
319	/* Matches kref_put() in gadget_unbind(). */
320	kref_get(&dev->count);
321	return ret;
322}
323
324static void gadget_unbind(struct usb_gadget *gadget)
325{
326	struct raw_dev *dev = get_gadget_data(gadget);
327
328	set_gadget_data(gadget, NULL);
329	/* Matches kref_get() in gadget_bind(). */
330	kref_put(&dev->count, dev_free);
331}
332
333static int gadget_setup(struct usb_gadget *gadget,
334			const struct usb_ctrlrequest *ctrl)
335{
336	int ret = 0;
337	struct raw_dev *dev = get_gadget_data(gadget);
338	unsigned long flags;
339
340	spin_lock_irqsave(&dev->lock, flags);
341	if (dev->state != STATE_DEV_RUNNING) {
342		dev_err(&gadget->dev, "ignoring, device is not running\n");
343		ret = -ENODEV;
344		goto out_unlock;
345	}
346	if (dev->ep0_in_pending || dev->ep0_out_pending) {
347		dev_dbg(&gadget->dev, "stalling, request already pending\n");
348		ret = -EBUSY;
349		goto out_unlock;
350	}
351	if ((ctrl->bRequestType & USB_DIR_IN) && ctrl->wLength)
352		dev->ep0_in_pending = true;
353	else
354		dev->ep0_out_pending = true;
355	spin_unlock_irqrestore(&dev->lock, flags);
356
357	ret = raw_queue_event(dev, USB_RAW_EVENT_CONTROL, sizeof(*ctrl), ctrl);
358	if (ret < 0)
359		dev_err(&gadget->dev, "failed to queue event\n");
360	goto out;
361
362out_unlock:
363	spin_unlock_irqrestore(&dev->lock, flags);
364out:
365	return ret;
366}
367
368/* These are currently unused but present in case UDC driver requires them. */
369static void gadget_disconnect(struct usb_gadget *gadget) { }
370static void gadget_suspend(struct usb_gadget *gadget) { }
371static void gadget_resume(struct usb_gadget *gadget) { }
372static void gadget_reset(struct usb_gadget *gadget) { }
373
374/*----------------------------------------------------------------------*/
375
376static struct miscdevice raw_misc_device;
377
378static int raw_open(struct inode *inode, struct file *fd)
379{
380	struct raw_dev *dev;
381
382	/* Nonblocking I/O is not supported yet. */
383	if (fd->f_flags & O_NONBLOCK)
384		return -EINVAL;
385
386	dev = dev_new();
387	if (!dev)
388		return -ENOMEM;
389	fd->private_data = dev;
390	dev->state = STATE_DEV_OPENED;
391	dev->dev = raw_misc_device.this_device;
392	return 0;
393}
394
395static int raw_release(struct inode *inode, struct file *fd)
396{
397	int ret = 0;
398	struct raw_dev *dev = fd->private_data;
399	unsigned long flags;
400	bool unregister = false;
401
402	spin_lock_irqsave(&dev->lock, flags);
403	dev->state = STATE_DEV_CLOSED;
404	if (!dev->gadget) {
405		spin_unlock_irqrestore(&dev->lock, flags);
406		goto out_put;
407	}
408	if (dev->gadget_registered)
409		unregister = true;
410	dev->gadget_registered = false;
411	spin_unlock_irqrestore(&dev->lock, flags);
412
413	if (unregister) {
414		ret = usb_gadget_unregister_driver(&dev->driver);
415		if (ret != 0)
416			dev_err(dev->dev,
417				"usb_gadget_unregister_driver() failed with %d\n",
418				ret);
419		/* Matches kref_get() in raw_ioctl_run(). */
420		kref_put(&dev->count, dev_free);
421	}
422
423out_put:
424	/* Matches dev_new() in raw_open(). */
425	kref_put(&dev->count, dev_free);
426	return ret;
427}
428
429/*----------------------------------------------------------------------*/
430
431static int raw_ioctl_init(struct raw_dev *dev, unsigned long value)
432{
433	int ret = 0;
434	int driver_id_number;
435	struct usb_raw_init arg;
436	char *udc_driver_name;
437	char *udc_device_name;
438	char *driver_driver_name;
439	unsigned long flags;
440
441	if (copy_from_user(&arg, (void __user *)value, sizeof(arg)))
442		return -EFAULT;
443
444	switch (arg.speed) {
445	case USB_SPEED_UNKNOWN:
446		arg.speed = USB_SPEED_HIGH;
447		break;
448	case USB_SPEED_LOW:
449	case USB_SPEED_FULL:
450	case USB_SPEED_HIGH:
451	case USB_SPEED_SUPER:
452		break;
453	default:
454		return -EINVAL;
455	}
456
457	driver_id_number = ida_alloc(&driver_id_numbers, GFP_KERNEL);
458	if (driver_id_number < 0)
459		return driver_id_number;
460
461	driver_driver_name = kmalloc(DRIVER_DRIVER_NAME_LENGTH_MAX, GFP_KERNEL);
462	if (!driver_driver_name) {
463		ret = -ENOMEM;
464		goto out_free_driver_id_number;
465	}
466	snprintf(driver_driver_name, DRIVER_DRIVER_NAME_LENGTH_MAX,
467				DRIVER_NAME ".%d", driver_id_number);
468
469	udc_driver_name = kmalloc(UDC_NAME_LENGTH_MAX, GFP_KERNEL);
470	if (!udc_driver_name) {
471		ret = -ENOMEM;
472		goto out_free_driver_driver_name;
473	}
474	ret = strscpy(udc_driver_name, &arg.driver_name[0],
475				UDC_NAME_LENGTH_MAX);
476	if (ret < 0)
477		goto out_free_udc_driver_name;
478	ret = 0;
479
480	udc_device_name = kmalloc(UDC_NAME_LENGTH_MAX, GFP_KERNEL);
481	if (!udc_device_name) {
482		ret = -ENOMEM;
483		goto out_free_udc_driver_name;
484	}
485	ret = strscpy(udc_device_name, &arg.device_name[0],
486				UDC_NAME_LENGTH_MAX);
487	if (ret < 0)
488		goto out_free_udc_device_name;
489	ret = 0;
490
491	spin_lock_irqsave(&dev->lock, flags);
492	if (dev->state != STATE_DEV_OPENED) {
493		dev_dbg(dev->dev, "fail, device is not opened\n");
494		ret = -EINVAL;
495		goto out_unlock;
496	}
497	dev->udc_name = udc_driver_name;
498
499	dev->driver.function = DRIVER_DESC;
500	dev->driver.max_speed = arg.speed;
501	dev->driver.setup = gadget_setup;
502	dev->driver.disconnect = gadget_disconnect;
503	dev->driver.bind = gadget_bind;
504	dev->driver.unbind = gadget_unbind;
505	dev->driver.suspend = gadget_suspend;
506	dev->driver.resume = gadget_resume;
507	dev->driver.reset = gadget_reset;
508	dev->driver.driver.name = driver_driver_name;
509	dev->driver.udc_name = udc_device_name;
510	dev->driver.match_existing_only = 1;
511	dev->driver_id_number = driver_id_number;
512
513	dev->state = STATE_DEV_INITIALIZED;
514	spin_unlock_irqrestore(&dev->lock, flags);
515	return ret;
516
517out_unlock:
518	spin_unlock_irqrestore(&dev->lock, flags);
519out_free_udc_device_name:
520	kfree(udc_device_name);
521out_free_udc_driver_name:
522	kfree(udc_driver_name);
523out_free_driver_driver_name:
524	kfree(driver_driver_name);
525out_free_driver_id_number:
526	ida_free(&driver_id_numbers, driver_id_number);
527	return ret;
528}
529
530static int raw_ioctl_run(struct raw_dev *dev, unsigned long value)
531{
532	int ret = 0;
533	unsigned long flags;
534
535	if (value)
536		return -EINVAL;
537
538	spin_lock_irqsave(&dev->lock, flags);
539	if (dev->state != STATE_DEV_INITIALIZED) {
540		dev_dbg(dev->dev, "fail, device is not initialized\n");
541		ret = -EINVAL;
542		goto out_unlock;
543	}
544	dev->state = STATE_DEV_REGISTERING;
545	spin_unlock_irqrestore(&dev->lock, flags);
546
547	ret = usb_gadget_probe_driver(&dev->driver);
548
549	spin_lock_irqsave(&dev->lock, flags);
550	if (ret) {
551		dev_err(dev->dev,
552			"fail, usb_gadget_probe_driver returned %d\n", ret);
553		dev->state = STATE_DEV_FAILED;
554		goto out_unlock;
555	}
556	dev->gadget_registered = true;
557	dev->state = STATE_DEV_RUNNING;
558	/* Matches kref_put() in raw_release(). */
559	kref_get(&dev->count);
560
561out_unlock:
562	spin_unlock_irqrestore(&dev->lock, flags);
563	return ret;
564}
565
566static int raw_ioctl_event_fetch(struct raw_dev *dev, unsigned long value)
567{
568	struct usb_raw_event arg;
569	unsigned long flags;
570	struct usb_raw_event *event;
571	uint32_t length;
572
573	if (copy_from_user(&arg, (void __user *)value, sizeof(arg)))
574		return -EFAULT;
575
576	spin_lock_irqsave(&dev->lock, flags);
577	if (dev->state != STATE_DEV_RUNNING) {
578		dev_dbg(dev->dev, "fail, device is not running\n");
579		spin_unlock_irqrestore(&dev->lock, flags);
580		return -EINVAL;
581	}
582	if (!dev->gadget) {
583		dev_dbg(dev->dev, "fail, gadget is not bound\n");
584		spin_unlock_irqrestore(&dev->lock, flags);
585		return -EBUSY;
586	}
587	spin_unlock_irqrestore(&dev->lock, flags);
588
589	event = raw_event_queue_fetch(&dev->queue);
590	if (PTR_ERR(event) == -EINTR) {
591		dev_dbg(&dev->gadget->dev, "event fetching interrupted\n");
592		return -EINTR;
593	}
594	if (IS_ERR(event)) {
595		dev_err(&dev->gadget->dev, "failed to fetch event\n");
596		spin_lock_irqsave(&dev->lock, flags);
597		dev->state = STATE_DEV_FAILED;
598		spin_unlock_irqrestore(&dev->lock, flags);
599		return -ENODEV;
600	}
601	length = min(arg.length, event->length);
602	if (copy_to_user((void __user *)value, event, sizeof(*event) + length)) {
603		kfree(event);
604		return -EFAULT;
605	}
606
607	kfree(event);
608	return 0;
609}
610
611static void *raw_alloc_io_data(struct usb_raw_ep_io *io, void __user *ptr,
612				bool get_from_user)
613{
614	void *data;
615
616	if (copy_from_user(io, ptr, sizeof(*io)))
617		return ERR_PTR(-EFAULT);
618	if (io->ep >= USB_RAW_EPS_NUM_MAX)
619		return ERR_PTR(-EINVAL);
620	if (!usb_raw_io_flags_valid(io->flags))
621		return ERR_PTR(-EINVAL);
622	if (io->length > PAGE_SIZE)
623		return ERR_PTR(-EINVAL);
624	if (get_from_user)
625		data = memdup_user(ptr + sizeof(*io), io->length);
626	else {
627		data = kmalloc(io->length, GFP_KERNEL);
628		if (!data)
629			data = ERR_PTR(-ENOMEM);
630	}
631	return data;
632}
633
634static int raw_process_ep0_io(struct raw_dev *dev, struct usb_raw_ep_io *io,
635				void *data, bool in)
636{
637	int ret = 0;
638	unsigned long flags;
639
640	spin_lock_irqsave(&dev->lock, flags);
641	if (dev->state != STATE_DEV_RUNNING) {
642		dev_dbg(dev->dev, "fail, device is not running\n");
643		ret = -EINVAL;
644		goto out_unlock;
645	}
646	if (!dev->gadget) {
647		dev_dbg(dev->dev, "fail, gadget is not bound\n");
648		ret = -EBUSY;
649		goto out_unlock;
650	}
651	if (dev->ep0_urb_queued) {
652		dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
653		ret = -EBUSY;
654		goto out_unlock;
655	}
656	if ((in && !dev->ep0_in_pending) ||
657			(!in && !dev->ep0_out_pending)) {
658		dev_dbg(&dev->gadget->dev, "fail, wrong direction\n");
659		ret = -EBUSY;
660		goto out_unlock;
661	}
662	if (WARN_ON(in && dev->ep0_out_pending)) {
663		ret = -ENODEV;
664		dev->state = STATE_DEV_FAILED;
665		goto out_unlock;
666	}
667	if (WARN_ON(!in && dev->ep0_in_pending)) {
668		ret = -ENODEV;
669		dev->state = STATE_DEV_FAILED;
670		goto out_unlock;
671	}
672
673	dev->req->buf = data;
674	dev->req->length = io->length;
675	dev->req->zero = usb_raw_io_flags_zero(io->flags);
676	dev->ep0_urb_queued = true;
677	spin_unlock_irqrestore(&dev->lock, flags);
678
679	ret = usb_ep_queue(dev->gadget->ep0, dev->req, GFP_KERNEL);
680	if (ret) {
681		dev_err(&dev->gadget->dev,
682				"fail, usb_ep_queue returned %d\n", ret);
683		spin_lock_irqsave(&dev->lock, flags);
684		dev->state = STATE_DEV_FAILED;
685		goto out_queue_failed;
686	}
687
688	ret = wait_for_completion_interruptible(&dev->ep0_done);
689	if (ret) {
690		dev_dbg(&dev->gadget->dev, "wait interrupted\n");
691		usb_ep_dequeue(dev->gadget->ep0, dev->req);
692		wait_for_completion(&dev->ep0_done);
693		spin_lock_irqsave(&dev->lock, flags);
694		if (dev->ep0_status == -ECONNRESET)
695			dev->ep0_status = -EINTR;
696		goto out_interrupted;
697	}
698
699	spin_lock_irqsave(&dev->lock, flags);
700
701out_interrupted:
702	ret = dev->ep0_status;
703out_queue_failed:
704	dev->ep0_urb_queued = false;
705out_unlock:
706	spin_unlock_irqrestore(&dev->lock, flags);
707	return ret;
708}
709
710static int raw_ioctl_ep0_write(struct raw_dev *dev, unsigned long value)
711{
712	int ret = 0;
713	void *data;
714	struct usb_raw_ep_io io;
715
716	data = raw_alloc_io_data(&io, (void __user *)value, true);
717	if (IS_ERR(data))
718		return PTR_ERR(data);
719	ret = raw_process_ep0_io(dev, &io, data, true);
720	kfree(data);
721	return ret;
722}
723
724static int raw_ioctl_ep0_read(struct raw_dev *dev, unsigned long value)
725{
726	int ret = 0;
727	void *data;
728	struct usb_raw_ep_io io;
729	unsigned int length;
730
731	data = raw_alloc_io_data(&io, (void __user *)value, false);
732	if (IS_ERR(data))
733		return PTR_ERR(data);
734	ret = raw_process_ep0_io(dev, &io, data, false);
735	if (ret < 0)
736		goto free;
737
738	length = min(io.length, (unsigned int)ret);
739	if (copy_to_user((void __user *)(value + sizeof(io)), data, length))
740		ret = -EFAULT;
741	else
742		ret = length;
743free:
744	kfree(data);
745	return ret;
746}
747
748static int raw_ioctl_ep0_stall(struct raw_dev *dev, unsigned long value)
749{
750	int ret = 0;
751	unsigned long flags;
752
753	if (value)
754		return -EINVAL;
755	spin_lock_irqsave(&dev->lock, flags);
756	if (dev->state != STATE_DEV_RUNNING) {
757		dev_dbg(dev->dev, "fail, device is not running\n");
758		ret = -EINVAL;
759		goto out_unlock;
760	}
761	if (!dev->gadget) {
762		dev_dbg(dev->dev, "fail, gadget is not bound\n");
763		ret = -EBUSY;
764		goto out_unlock;
765	}
766	if (dev->ep0_urb_queued) {
767		dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
768		ret = -EBUSY;
769		goto out_unlock;
770	}
771	if (!dev->ep0_in_pending && !dev->ep0_out_pending) {
772		dev_dbg(&dev->gadget->dev, "fail, no request pending\n");
773		ret = -EBUSY;
774		goto out_unlock;
775	}
776
777	ret = usb_ep_set_halt(dev->gadget->ep0);
778	if (ret < 0)
779		dev_err(&dev->gadget->dev,
780				"fail, usb_ep_set_halt returned %d\n", ret);
781
782	if (dev->ep0_in_pending)
783		dev->ep0_in_pending = false;
784	else
785		dev->ep0_out_pending = false;
786
787out_unlock:
788	spin_unlock_irqrestore(&dev->lock, flags);
789	return ret;
790}
791
792static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
793{
794	int ret = 0, i;
795	unsigned long flags;
796	struct usb_endpoint_descriptor *desc;
797	struct raw_ep *ep;
798
799	desc = memdup_user((void __user *)value, sizeof(*desc));
800	if (IS_ERR(desc))
801		return PTR_ERR(desc);
802
803	/*
804	 * Endpoints with a maxpacket length of 0 can cause crashes in UDC
805	 * drivers.
806	 */
807	if (usb_endpoint_maxp(desc) == 0) {
808		dev_dbg(dev->dev, "fail, bad endpoint maxpacket\n");
809		kfree(desc);
810		return -EINVAL;
811	}
812
813	spin_lock_irqsave(&dev->lock, flags);
814	if (dev->state != STATE_DEV_RUNNING) {
815		dev_dbg(dev->dev, "fail, device is not running\n");
816		ret = -EINVAL;
817		goto out_free;
818	}
819	if (!dev->gadget) {
820		dev_dbg(dev->dev, "fail, gadget is not bound\n");
821		ret = -EBUSY;
822		goto out_free;
823	}
824
825	for (i = 0; i < dev->eps_num; i++) {
826		ep = &dev->eps[i];
827		if (ep->state != STATE_EP_DISABLED)
828			continue;
829		if (ep->addr != usb_endpoint_num(desc) &&
830				ep->addr != USB_RAW_EP_ADDR_ANY)
831			continue;
832		if (!usb_gadget_ep_match_desc(dev->gadget, ep->ep, desc, NULL))
833			continue;
834		ep->ep->desc = desc;
835		ret = usb_ep_enable(ep->ep);
836		if (ret < 0) {
837			dev_err(&dev->gadget->dev,
838				"fail, usb_ep_enable returned %d\n", ret);
839			goto out_free;
840		}
841		ep->req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC);
842		if (!ep->req) {
843			dev_err(&dev->gadget->dev,
844				"fail, usb_ep_alloc_request failed\n");
845			usb_ep_disable(ep->ep);
846			ret = -ENOMEM;
847			goto out_free;
848		}
849		ep->state = STATE_EP_ENABLED;
850		ep->ep->driver_data = ep;
851		ret = i;
852		goto out_unlock;
853	}
854
855	dev_dbg(&dev->gadget->dev, "fail, no gadget endpoints available\n");
856	ret = -EBUSY;
857
858out_free:
859	kfree(desc);
860out_unlock:
861	spin_unlock_irqrestore(&dev->lock, flags);
862	return ret;
863}
864
865static int raw_ioctl_ep_disable(struct raw_dev *dev, unsigned long value)
866{
867	int ret = 0, i = value;
868	unsigned long flags;
869
870	spin_lock_irqsave(&dev->lock, flags);
871	if (dev->state != STATE_DEV_RUNNING) {
872		dev_dbg(dev->dev, "fail, device is not running\n");
873		ret = -EINVAL;
874		goto out_unlock;
875	}
876	if (!dev->gadget) {
877		dev_dbg(dev->dev, "fail, gadget is not bound\n");
878		ret = -EBUSY;
879		goto out_unlock;
880	}
881	if (i < 0 || i >= dev->eps_num) {
882		dev_dbg(dev->dev, "fail, invalid endpoint\n");
883		ret = -EBUSY;
884		goto out_unlock;
885	}
886	if (dev->eps[i].state == STATE_EP_DISABLED) {
887		dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
888		ret = -EINVAL;
889		goto out_unlock;
890	}
891	if (dev->eps[i].disabling) {
892		dev_dbg(&dev->gadget->dev,
893				"fail, disable already in progress\n");
894		ret = -EINVAL;
895		goto out_unlock;
896	}
897	if (dev->eps[i].urb_queued) {
898		dev_dbg(&dev->gadget->dev,
899				"fail, waiting for urb completion\n");
900		ret = -EINVAL;
901		goto out_unlock;
902	}
903	dev->eps[i].disabling = true;
904	spin_unlock_irqrestore(&dev->lock, flags);
905
906	usb_ep_disable(dev->eps[i].ep);
907
908	spin_lock_irqsave(&dev->lock, flags);
909	usb_ep_free_request(dev->eps[i].ep, dev->eps[i].req);
910	kfree(dev->eps[i].ep->desc);
911	dev->eps[i].state = STATE_EP_DISABLED;
912	dev->eps[i].disabling = false;
913
914out_unlock:
915	spin_unlock_irqrestore(&dev->lock, flags);
916	return ret;
917}
918
919static int raw_ioctl_ep_set_clear_halt_wedge(struct raw_dev *dev,
920		unsigned long value, bool set, bool halt)
921{
922	int ret = 0, i = value;
923	unsigned long flags;
924
925	spin_lock_irqsave(&dev->lock, flags);
926	if (dev->state != STATE_DEV_RUNNING) {
927		dev_dbg(dev->dev, "fail, device is not running\n");
928		ret = -EINVAL;
929		goto out_unlock;
930	}
931	if (!dev->gadget) {
932		dev_dbg(dev->dev, "fail, gadget is not bound\n");
933		ret = -EBUSY;
934		goto out_unlock;
935	}
936	if (i < 0 || i >= dev->eps_num) {
937		dev_dbg(dev->dev, "fail, invalid endpoint\n");
938		ret = -EBUSY;
939		goto out_unlock;
940	}
941	if (dev->eps[i].state == STATE_EP_DISABLED) {
942		dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
943		ret = -EINVAL;
944		goto out_unlock;
945	}
946	if (dev->eps[i].disabling) {
947		dev_dbg(&dev->gadget->dev,
948				"fail, disable is in progress\n");
949		ret = -EINVAL;
950		goto out_unlock;
951	}
952	if (dev->eps[i].urb_queued) {
953		dev_dbg(&dev->gadget->dev,
954				"fail, waiting for urb completion\n");
955		ret = -EINVAL;
956		goto out_unlock;
957	}
958	if (usb_endpoint_xfer_isoc(dev->eps[i].ep->desc)) {
959		dev_dbg(&dev->gadget->dev,
960				"fail, can't halt/wedge ISO endpoint\n");
961		ret = -EINVAL;
962		goto out_unlock;
963	}
964
965	if (set && halt) {
966		ret = usb_ep_set_halt(dev->eps[i].ep);
967		if (ret < 0)
968			dev_err(&dev->gadget->dev,
969				"fail, usb_ep_set_halt returned %d\n", ret);
970	} else if (!set && halt) {
971		ret = usb_ep_clear_halt(dev->eps[i].ep);
972		if (ret < 0)
973			dev_err(&dev->gadget->dev,
974				"fail, usb_ep_clear_halt returned %d\n", ret);
975	} else if (set && !halt) {
976		ret = usb_ep_set_wedge(dev->eps[i].ep);
977		if (ret < 0)
978			dev_err(&dev->gadget->dev,
979				"fail, usb_ep_set_wedge returned %d\n", ret);
980	}
981
982out_unlock:
983	spin_unlock_irqrestore(&dev->lock, flags);
984	return ret;
985}
986
987static void gadget_ep_complete(struct usb_ep *ep, struct usb_request *req)
988{
989	struct raw_ep *r_ep = (struct raw_ep *)ep->driver_data;
990	struct raw_dev *dev = r_ep->dev;
991	unsigned long flags;
992
993	spin_lock_irqsave(&dev->lock, flags);
994	if (req->status)
995		r_ep->status = req->status;
996	else
997		r_ep->status = req->actual;
998	spin_unlock_irqrestore(&dev->lock, flags);
999
1000	complete((struct completion *)req->context);
1001}
1002
1003static int raw_process_ep_io(struct raw_dev *dev, struct usb_raw_ep_io *io,
1004				void *data, bool in)
1005{
1006	int ret = 0;
1007	unsigned long flags;
1008	struct raw_ep *ep;
1009	DECLARE_COMPLETION_ONSTACK(done);
1010
1011	spin_lock_irqsave(&dev->lock, flags);
1012	if (dev->state != STATE_DEV_RUNNING) {
1013		dev_dbg(dev->dev, "fail, device is not running\n");
1014		ret = -EINVAL;
1015		goto out_unlock;
1016	}
1017	if (!dev->gadget) {
1018		dev_dbg(dev->dev, "fail, gadget is not bound\n");
1019		ret = -EBUSY;
1020		goto out_unlock;
1021	}
1022	if (io->ep >= dev->eps_num) {
1023		dev_dbg(&dev->gadget->dev, "fail, invalid endpoint\n");
1024		ret = -EINVAL;
1025		goto out_unlock;
1026	}
1027	ep = &dev->eps[io->ep];
1028	if (ep->state != STATE_EP_ENABLED) {
1029		dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
1030		ret = -EBUSY;
1031		goto out_unlock;
1032	}
1033	if (ep->disabling) {
1034		dev_dbg(&dev->gadget->dev,
1035				"fail, endpoint is already being disabled\n");
1036		ret = -EBUSY;
1037		goto out_unlock;
1038	}
1039	if (ep->urb_queued) {
1040		dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
1041		ret = -EBUSY;
1042		goto out_unlock;
1043	}
1044	if (in != usb_endpoint_dir_in(ep->ep->desc)) {
1045		dev_dbg(&dev->gadget->dev, "fail, wrong direction\n");
1046		ret = -EINVAL;
1047		goto out_unlock;
1048	}
1049
1050	ep->dev = dev;
1051	ep->req->context = &done;
1052	ep->req->complete = gadget_ep_complete;
1053	ep->req->buf = data;
1054	ep->req->length = io->length;
1055	ep->req->zero = usb_raw_io_flags_zero(io->flags);
1056	ep->urb_queued = true;
1057	spin_unlock_irqrestore(&dev->lock, flags);
1058
1059	ret = usb_ep_queue(ep->ep, ep->req, GFP_KERNEL);
1060	if (ret) {
1061		dev_err(&dev->gadget->dev,
1062				"fail, usb_ep_queue returned %d\n", ret);
1063		spin_lock_irqsave(&dev->lock, flags);
1064		dev->state = STATE_DEV_FAILED;
1065		goto out_queue_failed;
1066	}
1067
1068	ret = wait_for_completion_interruptible(&done);
1069	if (ret) {
1070		dev_dbg(&dev->gadget->dev, "wait interrupted\n");
1071		usb_ep_dequeue(ep->ep, ep->req);
1072		wait_for_completion(&done);
1073		spin_lock_irqsave(&dev->lock, flags);
1074		if (ep->status == -ECONNRESET)
1075			ep->status = -EINTR;
1076		goto out_interrupted;
1077	}
1078
1079	spin_lock_irqsave(&dev->lock, flags);
1080
1081out_interrupted:
1082	ret = ep->status;
1083out_queue_failed:
1084	ep->urb_queued = false;
1085out_unlock:
1086	spin_unlock_irqrestore(&dev->lock, flags);
1087	return ret;
1088}
1089
1090static int raw_ioctl_ep_write(struct raw_dev *dev, unsigned long value)
1091{
1092	int ret = 0;
1093	char *data;
1094	struct usb_raw_ep_io io;
1095
1096	data = raw_alloc_io_data(&io, (void __user *)value, true);
1097	if (IS_ERR(data))
1098		return PTR_ERR(data);
1099	ret = raw_process_ep_io(dev, &io, data, true);
1100	kfree(data);
1101	return ret;
1102}
1103
1104static int raw_ioctl_ep_read(struct raw_dev *dev, unsigned long value)
1105{
1106	int ret = 0;
1107	char *data;
1108	struct usb_raw_ep_io io;
1109	unsigned int length;
1110
1111	data = raw_alloc_io_data(&io, (void __user *)value, false);
1112	if (IS_ERR(data))
1113		return PTR_ERR(data);
1114	ret = raw_process_ep_io(dev, &io, data, false);
1115	if (ret < 0)
1116		goto free;
1117
1118	length = min(io.length, (unsigned int)ret);
1119	if (copy_to_user((void __user *)(value + sizeof(io)), data, length))
1120		ret = -EFAULT;
1121	else
1122		ret = length;
1123free:
1124	kfree(data);
1125	return ret;
1126}
1127
1128static int raw_ioctl_configure(struct raw_dev *dev, unsigned long value)
1129{
1130	int ret = 0;
1131	unsigned long flags;
1132
1133	if (value)
1134		return -EINVAL;
1135	spin_lock_irqsave(&dev->lock, flags);
1136	if (dev->state != STATE_DEV_RUNNING) {
1137		dev_dbg(dev->dev, "fail, device is not running\n");
1138		ret = -EINVAL;
1139		goto out_unlock;
1140	}
1141	if (!dev->gadget) {
1142		dev_dbg(dev->dev, "fail, gadget is not bound\n");
1143		ret = -EBUSY;
1144		goto out_unlock;
1145	}
1146	usb_gadget_set_state(dev->gadget, USB_STATE_CONFIGURED);
1147
1148out_unlock:
1149	spin_unlock_irqrestore(&dev->lock, flags);
1150	return ret;
1151}
1152
1153static int raw_ioctl_vbus_draw(struct raw_dev *dev, unsigned long value)
1154{
1155	int ret = 0;
1156	unsigned long flags;
1157
1158	spin_lock_irqsave(&dev->lock, flags);
1159	if (dev->state != STATE_DEV_RUNNING) {
1160		dev_dbg(dev->dev, "fail, device is not running\n");
1161		ret = -EINVAL;
1162		goto out_unlock;
1163	}
1164	if (!dev->gadget) {
1165		dev_dbg(dev->dev, "fail, gadget is not bound\n");
1166		ret = -EBUSY;
1167		goto out_unlock;
1168	}
1169	usb_gadget_vbus_draw(dev->gadget, 2 * value);
1170
1171out_unlock:
1172	spin_unlock_irqrestore(&dev->lock, flags);
1173	return ret;
1174}
1175
1176static void fill_ep_caps(struct usb_ep_caps *caps,
1177				struct usb_raw_ep_caps *raw_caps)
1178{
1179	raw_caps->type_control = caps->type_control;
1180	raw_caps->type_iso = caps->type_iso;
1181	raw_caps->type_bulk = caps->type_bulk;
1182	raw_caps->type_int = caps->type_int;
1183	raw_caps->dir_in = caps->dir_in;
1184	raw_caps->dir_out = caps->dir_out;
1185}
1186
1187static void fill_ep_limits(struct usb_ep *ep, struct usb_raw_ep_limits *limits)
1188{
1189	limits->maxpacket_limit = ep->maxpacket_limit;
1190	limits->max_streams = ep->max_streams;
1191}
1192
1193static int raw_ioctl_eps_info(struct raw_dev *dev, unsigned long value)
1194{
1195	int ret = 0, i;
1196	unsigned long flags;
1197	struct usb_raw_eps_info *info;
1198	struct raw_ep *ep;
1199
1200	info = kmalloc(sizeof(*info), GFP_KERNEL);
1201	if (!info) {
1202		ret = -ENOMEM;
1203		goto out;
1204	}
1205
1206	spin_lock_irqsave(&dev->lock, flags);
1207	if (dev->state != STATE_DEV_RUNNING) {
1208		dev_dbg(dev->dev, "fail, device is not running\n");
1209		ret = -EINVAL;
1210		spin_unlock_irqrestore(&dev->lock, flags);
1211		goto out_free;
1212	}
1213	if (!dev->gadget) {
1214		dev_dbg(dev->dev, "fail, gadget is not bound\n");
1215		ret = -EBUSY;
1216		spin_unlock_irqrestore(&dev->lock, flags);
1217		goto out_free;
1218	}
1219
1220	memset(info, 0, sizeof(*info));
1221	for (i = 0; i < dev->eps_num; i++) {
1222		ep = &dev->eps[i];
1223		strscpy(&info->eps[i].name[0], ep->ep->name,
1224				USB_RAW_EP_NAME_MAX);
1225		info->eps[i].addr = ep->addr;
1226		fill_ep_caps(&ep->ep->caps, &info->eps[i].caps);
1227		fill_ep_limits(ep->ep, &info->eps[i].limits);
1228	}
1229	ret = dev->eps_num;
1230	spin_unlock_irqrestore(&dev->lock, flags);
1231
1232	if (copy_to_user((void __user *)value, info, sizeof(*info)))
1233		ret = -EFAULT;
1234
1235out_free:
1236	kfree(info);
1237out:
1238	return ret;
1239}
1240
1241static long raw_ioctl(struct file *fd, unsigned int cmd, unsigned long value)
1242{
1243	struct raw_dev *dev = fd->private_data;
1244	int ret = 0;
1245
1246	if (!dev)
1247		return -EBUSY;
1248
1249	switch (cmd) {
1250	case USB_RAW_IOCTL_INIT:
1251		ret = raw_ioctl_init(dev, value);
1252		break;
1253	case USB_RAW_IOCTL_RUN:
1254		ret = raw_ioctl_run(dev, value);
1255		break;
1256	case USB_RAW_IOCTL_EVENT_FETCH:
1257		ret = raw_ioctl_event_fetch(dev, value);
1258		break;
1259	case USB_RAW_IOCTL_EP0_WRITE:
1260		ret = raw_ioctl_ep0_write(dev, value);
1261		break;
1262	case USB_RAW_IOCTL_EP0_READ:
1263		ret = raw_ioctl_ep0_read(dev, value);
1264		break;
1265	case USB_RAW_IOCTL_EP_ENABLE:
1266		ret = raw_ioctl_ep_enable(dev, value);
1267		break;
1268	case USB_RAW_IOCTL_EP_DISABLE:
1269		ret = raw_ioctl_ep_disable(dev, value);
1270		break;
1271	case USB_RAW_IOCTL_EP_WRITE:
1272		ret = raw_ioctl_ep_write(dev, value);
1273		break;
1274	case USB_RAW_IOCTL_EP_READ:
1275		ret = raw_ioctl_ep_read(dev, value);
1276		break;
1277	case USB_RAW_IOCTL_CONFIGURE:
1278		ret = raw_ioctl_configure(dev, value);
1279		break;
1280	case USB_RAW_IOCTL_VBUS_DRAW:
1281		ret = raw_ioctl_vbus_draw(dev, value);
1282		break;
1283	case USB_RAW_IOCTL_EPS_INFO:
1284		ret = raw_ioctl_eps_info(dev, value);
1285		break;
1286	case USB_RAW_IOCTL_EP0_STALL:
1287		ret = raw_ioctl_ep0_stall(dev, value);
1288		break;
1289	case USB_RAW_IOCTL_EP_SET_HALT:
1290		ret = raw_ioctl_ep_set_clear_halt_wedge(
1291					dev, value, true, true);
1292		break;
1293	case USB_RAW_IOCTL_EP_CLEAR_HALT:
1294		ret = raw_ioctl_ep_set_clear_halt_wedge(
1295					dev, value, false, true);
1296		break;
1297	case USB_RAW_IOCTL_EP_SET_WEDGE:
1298		ret = raw_ioctl_ep_set_clear_halt_wedge(
1299					dev, value, true, false);
1300		break;
1301	default:
1302		ret = -EINVAL;
1303	}
1304
1305	return ret;
1306}
1307
1308/*----------------------------------------------------------------------*/
1309
1310static const struct file_operations raw_fops = {
1311	.open =			raw_open,
1312	.unlocked_ioctl =	raw_ioctl,
1313	.compat_ioctl =		raw_ioctl,
1314	.release =		raw_release,
1315	.llseek =		no_llseek,
1316};
1317
1318static struct miscdevice raw_misc_device = {
1319	.minor = MISC_DYNAMIC_MINOR,
1320	.name = DRIVER_NAME,
1321	.fops = &raw_fops,
1322};
1323
1324module_misc_device(raw_misc_device);
1325