1 /*
2 * inode.c -- user mode filesystem api for usb gadget controllers
3 *
4 * Copyright (C) 2003-2004 David Brownell
5 * Copyright (C) 2003 Agilent Technologies
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13
14 /* #define VERBOSE_DEBUG */
15
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/fs.h>
19 #include <linux/pagemap.h>
20 #include <linux/uts.h>
21 #include <linux/wait.h>
22 #include <linux/compiler.h>
23 #include <asm/uaccess.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/poll.h>
27 #include <linux/mmu_context.h>
28 #include <linux/aio.h>
29 #include <linux/uio.h>
30 #include <linux/delay.h>
31 #include <linux/device.h>
32 #include <linux/moduleparam.h>
33
34 #include <linux/usb/gadgetfs.h>
35 #include <linux/usb/gadget.h>
36
37
38 /*
39 * The gadgetfs API maps each endpoint to a file descriptor so that you
40 * can use standard synchronous read/write calls for I/O. There's some
41 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
42 * drivers show how this works in practice. You can also use AIO to
43 * eliminate I/O gaps between requests, to help when streaming data.
44 *
45 * Key parts that must be USB-specific are protocols defining how the
46 * read/write operations relate to the hardware state machines. There
47 * are two types of files. One type is for the device, implementing ep0.
48 * The other type is for each IN or OUT endpoint. In both cases, the
49 * user mode driver must configure the hardware before using it.
50 *
51 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
52 * (by writing configuration and device descriptors). Afterwards it
53 * may serve as a source of device events, used to handle all control
54 * requests other than basic enumeration.
55 *
56 * - Then, after a SET_CONFIGURATION control request, ep_config() is
57 * called when each /dev/gadget/ep* file is configured (by writing
58 * endpoint descriptors). Afterwards these files are used to write()
59 * IN data or to read() OUT data. To halt the endpoint, a "wrong
60 * direction" request is issued (like reading an IN endpoint).
61 *
62 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
63 * not possible on all hardware. For example, precise fault handling with
64 * respect to data left in endpoint fifos after aborted operations; or
65 * selective clearing of endpoint halts, to implement SET_INTERFACE.
66 */
67
68 #define DRIVER_DESC "USB Gadget filesystem"
69 #define DRIVER_VERSION "24 Aug 2004"
70
71 static const char driver_desc [] = DRIVER_DESC;
72 static const char shortname [] = "gadgetfs";
73
74 MODULE_DESCRIPTION (DRIVER_DESC);
75 MODULE_AUTHOR ("David Brownell");
76 MODULE_LICENSE ("GPL");
77
78 static int ep_open(struct inode *, struct file *);
79
80
81 /*----------------------------------------------------------------------*/
82
83 #define GADGETFS_MAGIC 0xaee71ee7
84
85 /* /dev/gadget/$CHIP represents ep0 and the whole device */
86 enum ep0_state {
87 /* DISBLED is the initial state.
88 */
89 STATE_DEV_DISABLED = 0,
90
91 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
92 * ep0/device i/o modes and binding to the controller. Driver
93 * must always write descriptors to initialize the device, then
94 * the device becomes UNCONNECTED until enumeration.
95 */
96 STATE_DEV_OPENED,
97
98 /* From then on, ep0 fd is in either of two basic modes:
99 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
100 * - SETUP: read/write will transfer control data and succeed;
101 * or if "wrong direction", performs protocol stall
102 */
103 STATE_DEV_UNCONNECTED,
104 STATE_DEV_CONNECTED,
105 STATE_DEV_SETUP,
106
107 /* UNBOUND means the driver closed ep0, so the device won't be
108 * accessible again (DEV_DISABLED) until all fds are closed.
109 */
110 STATE_DEV_UNBOUND,
111 };
112
113 /* enough for the whole queue: most events invalidate others */
114 #define N_EVENT 5
115
116 #define RBUF_SIZE 256
117
118 struct dev_data {
119 spinlock_t lock;
120 atomic_t count;
121 int udc_usage;
122 enum ep0_state state; /* P: lock */
123 struct usb_gadgetfs_event event [N_EVENT];
124 unsigned ev_next;
125 struct fasync_struct *fasync;
126 u8 current_config;
127
128 /* drivers reading ep0 MUST handle control requests (SETUP)
129 * reported that way; else the host will time out.
130 */
131 unsigned usermode_setup : 1,
132 setup_in : 1,
133 setup_can_stall : 1,
134 setup_out_ready : 1,
135 setup_out_error : 1,
136 setup_abort : 1;
137 unsigned setup_wLength;
138
139 /* the rest is basically write-once */
140 struct usb_config_descriptor *config, *hs_config;
141 struct usb_device_descriptor *dev;
142 struct usb_request *req;
143 struct usb_gadget *gadget;
144 struct list_head epfiles;
145 void *buf;
146 wait_queue_head_t wait;
147 struct super_block *sb;
148 struct dentry *dentry;
149
150 /* except this scratch i/o buffer for ep0 */
151 u8 rbuf[RBUF_SIZE];
152 };
153
get_dev(struct dev_data * data)154 static inline void get_dev (struct dev_data *data)
155 {
156 atomic_inc (&data->count);
157 }
158
put_dev(struct dev_data * data)159 static void put_dev (struct dev_data *data)
160 {
161 if (likely (!atomic_dec_and_test (&data->count)))
162 return;
163 /* needs no more cleanup */
164 BUG_ON (waitqueue_active (&data->wait));
165 kfree (data);
166 }
167
dev_new(void)168 static struct dev_data *dev_new (void)
169 {
170 struct dev_data *dev;
171
172 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
173 if (!dev)
174 return NULL;
175 dev->state = STATE_DEV_DISABLED;
176 atomic_set (&dev->count, 1);
177 spin_lock_init (&dev->lock);
178 INIT_LIST_HEAD (&dev->epfiles);
179 init_waitqueue_head (&dev->wait);
180 return dev;
181 }
182
183 /*----------------------------------------------------------------------*/
184
185 /* other /dev/gadget/$ENDPOINT files represent endpoints */
186 enum ep_state {
187 STATE_EP_DISABLED = 0,
188 STATE_EP_READY,
189 STATE_EP_ENABLED,
190 STATE_EP_UNBOUND,
191 };
192
193 struct ep_data {
194 struct mutex lock;
195 enum ep_state state;
196 atomic_t count;
197 struct dev_data *dev;
198 /* must hold dev->lock before accessing ep or req */
199 struct usb_ep *ep;
200 struct usb_request *req;
201 ssize_t status;
202 char name [16];
203 struct usb_endpoint_descriptor desc, hs_desc;
204 struct list_head epfiles;
205 wait_queue_head_t wait;
206 struct dentry *dentry;
207 };
208
get_ep(struct ep_data * data)209 static inline void get_ep (struct ep_data *data)
210 {
211 atomic_inc (&data->count);
212 }
213
put_ep(struct ep_data * data)214 static void put_ep (struct ep_data *data)
215 {
216 if (likely (!atomic_dec_and_test (&data->count)))
217 return;
218 put_dev (data->dev);
219 /* needs no more cleanup */
220 BUG_ON (!list_empty (&data->epfiles));
221 BUG_ON (waitqueue_active (&data->wait));
222 kfree (data);
223 }
224
225 /*----------------------------------------------------------------------*/
226
227 /* most "how to use the hardware" policy choices are in userspace:
228 * mapping endpoint roles (which the driver needs) to the capabilities
229 * which the usb controller has. most of those capabilities are exposed
230 * implicitly, starting with the driver name and then endpoint names.
231 */
232
233 static const char *CHIP;
234
235 /*----------------------------------------------------------------------*/
236
237 /* NOTE: don't use dev_printk calls before binding to the gadget
238 * at the end of ep0 configuration, or after unbind.
239 */
240
241 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
242 #define xprintk(d,level,fmt,args...) \
243 printk(level "%s: " fmt , shortname , ## args)
244
245 #ifdef DEBUG
246 #define DBG(dev,fmt,args...) \
247 xprintk(dev , KERN_DEBUG , fmt , ## args)
248 #else
249 #define DBG(dev,fmt,args...) \
250 do { } while (0)
251 #endif /* DEBUG */
252
253 #ifdef VERBOSE_DEBUG
254 #define VDEBUG DBG
255 #else
256 #define VDEBUG(dev,fmt,args...) \
257 do { } while (0)
258 #endif /* DEBUG */
259
260 #define ERROR(dev,fmt,args...) \
261 xprintk(dev , KERN_ERR , fmt , ## args)
262 #define INFO(dev,fmt,args...) \
263 xprintk(dev , KERN_INFO , fmt , ## args)
264
265
266 /*----------------------------------------------------------------------*/
267
268 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
269 *
270 * After opening, configure non-control endpoints. Then use normal
271 * stream read() and write() requests; and maybe ioctl() to get more
272 * precise FIFO status when recovering from cancellation.
273 */
274
epio_complete(struct usb_ep * ep,struct usb_request * req)275 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
276 {
277 struct ep_data *epdata = ep->driver_data;
278
279 if (!req->context)
280 return;
281 if (req->status)
282 epdata->status = req->status;
283 else
284 epdata->status = req->actual;
285 complete ((struct completion *)req->context);
286 }
287
288 /* tasklock endpoint, returning when it's connected.
289 * still need dev->lock to use epdata->ep.
290 */
291 static int
get_ready_ep(unsigned f_flags,struct ep_data * epdata,bool is_write)292 get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
293 {
294 int val;
295
296 if (f_flags & O_NONBLOCK) {
297 if (!mutex_trylock(&epdata->lock))
298 goto nonblock;
299 if (epdata->state != STATE_EP_ENABLED &&
300 (!is_write || epdata->state != STATE_EP_READY)) {
301 mutex_unlock(&epdata->lock);
302 nonblock:
303 val = -EAGAIN;
304 } else
305 val = 0;
306 return val;
307 }
308
309 val = mutex_lock_interruptible(&epdata->lock);
310 if (val < 0)
311 return val;
312
313 switch (epdata->state) {
314 case STATE_EP_ENABLED:
315 return 0;
316 case STATE_EP_READY: /* not configured yet */
317 if (is_write)
318 return 0;
319 // FALLTHRU
320 case STATE_EP_UNBOUND: /* clean disconnect */
321 break;
322 // case STATE_EP_DISABLED: /* "can't happen" */
323 default: /* error! */
324 pr_debug ("%s: ep %p not available, state %d\n",
325 shortname, epdata, epdata->state);
326 }
327 mutex_unlock(&epdata->lock);
328 return -ENODEV;
329 }
330
331 static ssize_t
ep_io(struct ep_data * epdata,void * buf,unsigned len)332 ep_io (struct ep_data *epdata, void *buf, unsigned len)
333 {
334 DECLARE_COMPLETION_ONSTACK (done);
335 int value;
336
337 spin_lock_irq (&epdata->dev->lock);
338 if (likely (epdata->ep != NULL)) {
339 struct usb_request *req = epdata->req;
340
341 req->context = &done;
342 req->complete = epio_complete;
343 req->buf = buf;
344 req->length = len;
345 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
346 } else
347 value = -ENODEV;
348 spin_unlock_irq (&epdata->dev->lock);
349
350 if (likely (value == 0)) {
351 value = wait_event_interruptible (done.wait, done.done);
352 if (value != 0) {
353 spin_lock_irq (&epdata->dev->lock);
354 if (likely (epdata->ep != NULL)) {
355 DBG (epdata->dev, "%s i/o interrupted\n",
356 epdata->name);
357 usb_ep_dequeue (epdata->ep, epdata->req);
358 spin_unlock_irq (&epdata->dev->lock);
359
360 wait_event (done.wait, done.done);
361 if (epdata->status == -ECONNRESET)
362 epdata->status = -EINTR;
363 } else {
364 spin_unlock_irq (&epdata->dev->lock);
365
366 DBG (epdata->dev, "endpoint gone\n");
367 epdata->status = -ENODEV;
368 }
369 }
370 return epdata->status;
371 }
372 return value;
373 }
374
375 static int
ep_release(struct inode * inode,struct file * fd)376 ep_release (struct inode *inode, struct file *fd)
377 {
378 struct ep_data *data = fd->private_data;
379 int value;
380
381 value = mutex_lock_interruptible(&data->lock);
382 if (value < 0)
383 return value;
384
385 /* clean up if this can be reopened */
386 if (data->state != STATE_EP_UNBOUND) {
387 data->state = STATE_EP_DISABLED;
388 data->desc.bDescriptorType = 0;
389 data->hs_desc.bDescriptorType = 0;
390 usb_ep_disable(data->ep);
391 }
392 mutex_unlock(&data->lock);
393 put_ep (data);
394 return 0;
395 }
396
ep_ioctl(struct file * fd,unsigned code,unsigned long value)397 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
398 {
399 struct ep_data *data = fd->private_data;
400 int status;
401
402 if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
403 return status;
404
405 spin_lock_irq (&data->dev->lock);
406 if (likely (data->ep != NULL)) {
407 switch (code) {
408 case GADGETFS_FIFO_STATUS:
409 status = usb_ep_fifo_status (data->ep);
410 break;
411 case GADGETFS_FIFO_FLUSH:
412 usb_ep_fifo_flush (data->ep);
413 break;
414 case GADGETFS_CLEAR_HALT:
415 status = usb_ep_clear_halt (data->ep);
416 break;
417 default:
418 status = -ENOTTY;
419 }
420 } else
421 status = -ENODEV;
422 spin_unlock_irq (&data->dev->lock);
423 mutex_unlock(&data->lock);
424 return status;
425 }
426
427 /*----------------------------------------------------------------------*/
428
429 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
430
431 struct kiocb_priv {
432 struct usb_request *req;
433 struct ep_data *epdata;
434 struct kiocb *iocb;
435 struct mm_struct *mm;
436 struct work_struct work;
437 void *buf;
438 struct iov_iter to;
439 const void *to_free;
440 unsigned actual;
441 };
442
ep_aio_cancel(struct kiocb * iocb)443 static int ep_aio_cancel(struct kiocb *iocb)
444 {
445 struct kiocb_priv *priv = iocb->private;
446 struct ep_data *epdata;
447 int value;
448
449 local_irq_disable();
450 epdata = priv->epdata;
451 // spin_lock(&epdata->dev->lock);
452 if (likely(epdata && epdata->ep && priv->req))
453 value = usb_ep_dequeue (epdata->ep, priv->req);
454 else
455 value = -EINVAL;
456 // spin_unlock(&epdata->dev->lock);
457 local_irq_enable();
458
459 return value;
460 }
461
ep_user_copy_worker(struct work_struct * work)462 static void ep_user_copy_worker(struct work_struct *work)
463 {
464 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
465 struct mm_struct *mm = priv->mm;
466 struct kiocb *iocb = priv->iocb;
467 size_t ret;
468
469 use_mm(mm);
470 ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
471 unuse_mm(mm);
472 if (!ret)
473 ret = -EFAULT;
474
475 /* completing the iocb can drop the ctx and mm, don't touch mm after */
476 iocb->ki_complete(iocb, ret, ret);
477
478 kfree(priv->buf);
479 kfree(priv->to_free);
480 kfree(priv);
481 }
482
ep_aio_complete(struct usb_ep * ep,struct usb_request * req)483 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
484 {
485 struct kiocb *iocb = req->context;
486 struct kiocb_priv *priv = iocb->private;
487 struct ep_data *epdata = priv->epdata;
488
489 /* lock against disconnect (and ideally, cancel) */
490 spin_lock(&epdata->dev->lock);
491 priv->req = NULL;
492 priv->epdata = NULL;
493
494 /* if this was a write or a read returning no data then we
495 * don't need to copy anything to userspace, so we can
496 * complete the aio request immediately.
497 */
498 if (priv->to_free == NULL || unlikely(req->actual == 0)) {
499 kfree(req->buf);
500 kfree(priv->to_free);
501 kfree(priv);
502 iocb->private = NULL;
503 /* aio_complete() reports bytes-transferred _and_ faults */
504
505 iocb->ki_complete(iocb, req->actual ? req->actual : req->status,
506 req->status);
507 } else {
508 /* ep_copy_to_user() won't report both; we hide some faults */
509 if (unlikely(0 != req->status))
510 DBG(epdata->dev, "%s fault %d len %d\n",
511 ep->name, req->status, req->actual);
512
513 priv->buf = req->buf;
514 priv->actual = req->actual;
515 INIT_WORK(&priv->work, ep_user_copy_worker);
516 schedule_work(&priv->work);
517 }
518
519 usb_ep_free_request(ep, req);
520 spin_unlock(&epdata->dev->lock);
521 put_ep(epdata);
522 }
523
ep_aio(struct kiocb * iocb,struct kiocb_priv * priv,struct ep_data * epdata,char * buf,size_t len)524 static ssize_t ep_aio(struct kiocb *iocb,
525 struct kiocb_priv *priv,
526 struct ep_data *epdata,
527 char *buf,
528 size_t len)
529 {
530 struct usb_request *req;
531 ssize_t value;
532
533 iocb->private = priv;
534 priv->iocb = iocb;
535
536 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
537 get_ep(epdata);
538 priv->epdata = epdata;
539 priv->actual = 0;
540 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
541
542 /* each kiocb is coupled to one usb_request, but we can't
543 * allocate or submit those if the host disconnected.
544 */
545 spin_lock_irq(&epdata->dev->lock);
546 value = -ENODEV;
547 if (unlikely(epdata->ep == NULL))
548 goto fail;
549
550 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
551 value = -ENOMEM;
552 if (unlikely(!req))
553 goto fail;
554
555 priv->req = req;
556 req->buf = buf;
557 req->length = len;
558 req->complete = ep_aio_complete;
559 req->context = iocb;
560 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
561 if (unlikely(0 != value)) {
562 usb_ep_free_request(epdata->ep, req);
563 goto fail;
564 }
565 spin_unlock_irq(&epdata->dev->lock);
566 return -EIOCBQUEUED;
567
568 fail:
569 spin_unlock_irq(&epdata->dev->lock);
570 kfree(priv->to_free);
571 kfree(priv);
572 put_ep(epdata);
573 return value;
574 }
575
576 static ssize_t
ep_read_iter(struct kiocb * iocb,struct iov_iter * to)577 ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
578 {
579 struct file *file = iocb->ki_filp;
580 struct ep_data *epdata = file->private_data;
581 size_t len = iov_iter_count(to);
582 ssize_t value;
583 char *buf;
584
585 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
586 return value;
587
588 /* halt any endpoint by doing a "wrong direction" i/o call */
589 if (usb_endpoint_dir_in(&epdata->desc)) {
590 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
591 !is_sync_kiocb(iocb)) {
592 mutex_unlock(&epdata->lock);
593 return -EINVAL;
594 }
595 DBG (epdata->dev, "%s halt\n", epdata->name);
596 spin_lock_irq(&epdata->dev->lock);
597 if (likely(epdata->ep != NULL))
598 usb_ep_set_halt(epdata->ep);
599 spin_unlock_irq(&epdata->dev->lock);
600 mutex_unlock(&epdata->lock);
601 return -EBADMSG;
602 }
603
604 buf = kmalloc(len, GFP_KERNEL);
605 if (unlikely(!buf)) {
606 mutex_unlock(&epdata->lock);
607 return -ENOMEM;
608 }
609 if (is_sync_kiocb(iocb)) {
610 value = ep_io(epdata, buf, len);
611 if (value >= 0 && copy_to_iter(buf, value, to))
612 value = -EFAULT;
613 } else {
614 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
615 value = -ENOMEM;
616 if (!priv)
617 goto fail;
618 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
619 if (!priv->to_free) {
620 kfree(priv);
621 goto fail;
622 }
623 value = ep_aio(iocb, priv, epdata, buf, len);
624 if (value == -EIOCBQUEUED)
625 buf = NULL;
626 }
627 fail:
628 kfree(buf);
629 mutex_unlock(&epdata->lock);
630 return value;
631 }
632
633 static ssize_t ep_config(struct ep_data *, const char *, size_t);
634
635 static ssize_t
ep_write_iter(struct kiocb * iocb,struct iov_iter * from)636 ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
637 {
638 struct file *file = iocb->ki_filp;
639 struct ep_data *epdata = file->private_data;
640 size_t len = iov_iter_count(from);
641 bool configured;
642 ssize_t value;
643 char *buf;
644
645 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
646 return value;
647
648 configured = epdata->state == STATE_EP_ENABLED;
649
650 /* halt any endpoint by doing a "wrong direction" i/o call */
651 if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
652 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
653 !is_sync_kiocb(iocb)) {
654 mutex_unlock(&epdata->lock);
655 return -EINVAL;
656 }
657 DBG (epdata->dev, "%s halt\n", epdata->name);
658 spin_lock_irq(&epdata->dev->lock);
659 if (likely(epdata->ep != NULL))
660 usb_ep_set_halt(epdata->ep);
661 spin_unlock_irq(&epdata->dev->lock);
662 mutex_unlock(&epdata->lock);
663 return -EBADMSG;
664 }
665
666 buf = kmalloc(len, GFP_KERNEL);
667 if (unlikely(!buf)) {
668 mutex_unlock(&epdata->lock);
669 return -ENOMEM;
670 }
671
672 if (unlikely(copy_from_iter(buf, len, from) != len)) {
673 value = -EFAULT;
674 goto out;
675 }
676
677 if (unlikely(!configured)) {
678 value = ep_config(epdata, buf, len);
679 } else if (is_sync_kiocb(iocb)) {
680 value = ep_io(epdata, buf, len);
681 } else {
682 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
683 value = -ENOMEM;
684 if (priv) {
685 value = ep_aio(iocb, priv, epdata, buf, len);
686 if (value == -EIOCBQUEUED)
687 buf = NULL;
688 }
689 }
690 out:
691 kfree(buf);
692 mutex_unlock(&epdata->lock);
693 return value;
694 }
695
696 /*----------------------------------------------------------------------*/
697
698 /* used after endpoint configuration */
699 static const struct file_operations ep_io_operations = {
700 .owner = THIS_MODULE,
701
702 .open = ep_open,
703 .release = ep_release,
704 .llseek = no_llseek,
705 .unlocked_ioctl = ep_ioctl,
706 .read_iter = ep_read_iter,
707 .write_iter = ep_write_iter,
708 };
709
710 /* ENDPOINT INITIALIZATION
711 *
712 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
713 * status = write (fd, descriptors, sizeof descriptors)
714 *
715 * That write establishes the endpoint configuration, configuring
716 * the controller to process bulk, interrupt, or isochronous transfers
717 * at the right maxpacket size, and so on.
718 *
719 * The descriptors are message type 1, identified by a host order u32
720 * at the beginning of what's written. Descriptor order is: full/low
721 * speed descriptor, then optional high speed descriptor.
722 */
723 static ssize_t
ep_config(struct ep_data * data,const char * buf,size_t len)724 ep_config (struct ep_data *data, const char *buf, size_t len)
725 {
726 struct usb_ep *ep;
727 u32 tag;
728 int value, length = len;
729
730 if (data->state != STATE_EP_READY) {
731 value = -EL2HLT;
732 goto fail;
733 }
734
735 value = len;
736 if (len < USB_DT_ENDPOINT_SIZE + 4)
737 goto fail0;
738
739 /* we might need to change message format someday */
740 memcpy(&tag, buf, 4);
741 if (tag != 1) {
742 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
743 goto fail0;
744 }
745 buf += 4;
746 len -= 4;
747
748 /* NOTE: audio endpoint extensions not accepted here;
749 * just don't include the extra bytes.
750 */
751
752 /* full/low speed descriptor, then high speed */
753 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
754 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
755 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
756 goto fail0;
757 if (len != USB_DT_ENDPOINT_SIZE) {
758 if (len != 2 * USB_DT_ENDPOINT_SIZE)
759 goto fail0;
760 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
761 USB_DT_ENDPOINT_SIZE);
762 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
763 || data->hs_desc.bDescriptorType
764 != USB_DT_ENDPOINT) {
765 DBG(data->dev, "config %s, bad hs length or type\n",
766 data->name);
767 goto fail0;
768 }
769 }
770
771 spin_lock_irq (&data->dev->lock);
772 if (data->dev->state == STATE_DEV_UNBOUND) {
773 value = -ENOENT;
774 goto gone;
775 } else {
776 ep = data->ep;
777 if (ep == NULL) {
778 value = -ENODEV;
779 goto gone;
780 }
781 }
782 switch (data->dev->gadget->speed) {
783 case USB_SPEED_LOW:
784 case USB_SPEED_FULL:
785 ep->desc = &data->desc;
786 break;
787 case USB_SPEED_HIGH:
788 /* fails if caller didn't provide that descriptor... */
789 ep->desc = &data->hs_desc;
790 break;
791 default:
792 DBG(data->dev, "unconnected, %s init abandoned\n",
793 data->name);
794 value = -EINVAL;
795 goto gone;
796 }
797 value = usb_ep_enable(ep);
798 if (value == 0) {
799 data->state = STATE_EP_ENABLED;
800 value = length;
801 }
802 gone:
803 spin_unlock_irq (&data->dev->lock);
804 if (value < 0) {
805 fail:
806 data->desc.bDescriptorType = 0;
807 data->hs_desc.bDescriptorType = 0;
808 }
809 return value;
810 fail0:
811 value = -EINVAL;
812 goto fail;
813 }
814
815 static int
ep_open(struct inode * inode,struct file * fd)816 ep_open (struct inode *inode, struct file *fd)
817 {
818 struct ep_data *data = inode->i_private;
819 int value = -EBUSY;
820
821 if (mutex_lock_interruptible(&data->lock) != 0)
822 return -EINTR;
823 spin_lock_irq (&data->dev->lock);
824 if (data->dev->state == STATE_DEV_UNBOUND)
825 value = -ENOENT;
826 else if (data->state == STATE_EP_DISABLED) {
827 value = 0;
828 data->state = STATE_EP_READY;
829 get_ep (data);
830 fd->private_data = data;
831 VDEBUG (data->dev, "%s ready\n", data->name);
832 } else
833 DBG (data->dev, "%s state %d\n",
834 data->name, data->state);
835 spin_unlock_irq (&data->dev->lock);
836 mutex_unlock(&data->lock);
837 return value;
838 }
839
840 /*----------------------------------------------------------------------*/
841
842 /* EP0 IMPLEMENTATION can be partly in userspace.
843 *
844 * Drivers that use this facility receive various events, including
845 * control requests the kernel doesn't handle. Drivers that don't
846 * use this facility may be too simple-minded for real applications.
847 */
848
ep0_readable(struct dev_data * dev)849 static inline void ep0_readable (struct dev_data *dev)
850 {
851 wake_up (&dev->wait);
852 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
853 }
854
clean_req(struct usb_ep * ep,struct usb_request * req)855 static void clean_req (struct usb_ep *ep, struct usb_request *req)
856 {
857 struct dev_data *dev = ep->driver_data;
858
859 if (req->buf != dev->rbuf) {
860 kfree(req->buf);
861 req->buf = dev->rbuf;
862 }
863 req->complete = epio_complete;
864 dev->setup_out_ready = 0;
865 }
866
ep0_complete(struct usb_ep * ep,struct usb_request * req)867 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
868 {
869 struct dev_data *dev = ep->driver_data;
870 unsigned long flags;
871 int free = 1;
872
873 /* for control OUT, data must still get to userspace */
874 spin_lock_irqsave(&dev->lock, flags);
875 if (!dev->setup_in) {
876 dev->setup_out_error = (req->status != 0);
877 if (!dev->setup_out_error)
878 free = 0;
879 dev->setup_out_ready = 1;
880 ep0_readable (dev);
881 }
882
883 /* clean up as appropriate */
884 if (free && req->buf != &dev->rbuf)
885 clean_req (ep, req);
886 req->complete = epio_complete;
887 spin_unlock_irqrestore(&dev->lock, flags);
888 }
889
setup_req(struct usb_ep * ep,struct usb_request * req,u16 len)890 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
891 {
892 struct dev_data *dev = ep->driver_data;
893
894 if (dev->setup_out_ready) {
895 DBG (dev, "ep0 request busy!\n");
896 return -EBUSY;
897 }
898 if (len > sizeof (dev->rbuf))
899 req->buf = kmalloc(len, GFP_ATOMIC);
900 if (req->buf == NULL) {
901 req->buf = dev->rbuf;
902 return -ENOMEM;
903 }
904 req->complete = ep0_complete;
905 req->length = len;
906 req->zero = 0;
907 return 0;
908 }
909
910 static ssize_t
ep0_read(struct file * fd,char __user * buf,size_t len,loff_t * ptr)911 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
912 {
913 struct dev_data *dev = fd->private_data;
914 ssize_t retval;
915 enum ep0_state state;
916
917 spin_lock_irq (&dev->lock);
918 if (dev->state <= STATE_DEV_OPENED) {
919 retval = -EINVAL;
920 goto done;
921 }
922
923 /* report fd mode change before acting on it */
924 if (dev->setup_abort) {
925 dev->setup_abort = 0;
926 retval = -EIDRM;
927 goto done;
928 }
929
930 /* control DATA stage */
931 if ((state = dev->state) == STATE_DEV_SETUP) {
932
933 if (dev->setup_in) { /* stall IN */
934 VDEBUG(dev, "ep0in stall\n");
935 (void) usb_ep_set_halt (dev->gadget->ep0);
936 retval = -EL2HLT;
937 dev->state = STATE_DEV_CONNECTED;
938
939 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
940 struct usb_ep *ep = dev->gadget->ep0;
941 struct usb_request *req = dev->req;
942
943 if ((retval = setup_req (ep, req, 0)) == 0) {
944 ++dev->udc_usage;
945 spin_unlock_irq (&dev->lock);
946 retval = usb_ep_queue (ep, req, GFP_KERNEL);
947 spin_lock_irq (&dev->lock);
948 --dev->udc_usage;
949 }
950 dev->state = STATE_DEV_CONNECTED;
951
952 /* assume that was SET_CONFIGURATION */
953 if (dev->current_config) {
954 unsigned power;
955
956 if (gadget_is_dualspeed(dev->gadget)
957 && (dev->gadget->speed
958 == USB_SPEED_HIGH))
959 power = dev->hs_config->bMaxPower;
960 else
961 power = dev->config->bMaxPower;
962 usb_gadget_vbus_draw(dev->gadget, 2 * power);
963 }
964
965 } else { /* collect OUT data */
966 if ((fd->f_flags & O_NONBLOCK) != 0
967 && !dev->setup_out_ready) {
968 retval = -EAGAIN;
969 goto done;
970 }
971 spin_unlock_irq (&dev->lock);
972 retval = wait_event_interruptible (dev->wait,
973 dev->setup_out_ready != 0);
974
975 /* FIXME state could change from under us */
976 spin_lock_irq (&dev->lock);
977 if (retval)
978 goto done;
979
980 if (dev->state != STATE_DEV_SETUP) {
981 retval = -ECANCELED;
982 goto done;
983 }
984 dev->state = STATE_DEV_CONNECTED;
985
986 if (dev->setup_out_error)
987 retval = -EIO;
988 else {
989 len = min (len, (size_t)dev->req->actual);
990 ++dev->udc_usage;
991 spin_unlock_irq(&dev->lock);
992 if (copy_to_user (buf, dev->req->buf, len))
993 retval = -EFAULT;
994 else
995 retval = len;
996 spin_lock_irq(&dev->lock);
997 --dev->udc_usage;
998 clean_req (dev->gadget->ep0, dev->req);
999 /* NOTE userspace can't yet choose to stall */
1000 }
1001 }
1002 goto done;
1003 }
1004
1005 /* else normal: return event data */
1006 if (len < sizeof dev->event [0]) {
1007 retval = -EINVAL;
1008 goto done;
1009 }
1010 len -= len % sizeof (struct usb_gadgetfs_event);
1011 dev->usermode_setup = 1;
1012
1013 scan:
1014 /* return queued events right away */
1015 if (dev->ev_next != 0) {
1016 unsigned i, n;
1017
1018 n = len / sizeof (struct usb_gadgetfs_event);
1019 if (dev->ev_next < n)
1020 n = dev->ev_next;
1021
1022 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1023 for (i = 0; i < n; i++) {
1024 if (dev->event [i].type == GADGETFS_SETUP) {
1025 dev->state = STATE_DEV_SETUP;
1026 n = i + 1;
1027 break;
1028 }
1029 }
1030 spin_unlock_irq (&dev->lock);
1031 len = n * sizeof (struct usb_gadgetfs_event);
1032 if (copy_to_user (buf, &dev->event, len))
1033 retval = -EFAULT;
1034 else
1035 retval = len;
1036 if (len > 0) {
1037 /* NOTE this doesn't guard against broken drivers;
1038 * concurrent ep0 readers may lose events.
1039 */
1040 spin_lock_irq (&dev->lock);
1041 if (dev->ev_next > n) {
1042 memmove(&dev->event[0], &dev->event[n],
1043 sizeof (struct usb_gadgetfs_event)
1044 * (dev->ev_next - n));
1045 }
1046 dev->ev_next -= n;
1047 spin_unlock_irq (&dev->lock);
1048 }
1049 return retval;
1050 }
1051 if (fd->f_flags & O_NONBLOCK) {
1052 retval = -EAGAIN;
1053 goto done;
1054 }
1055
1056 switch (state) {
1057 default:
1058 DBG (dev, "fail %s, state %d\n", __func__, state);
1059 retval = -ESRCH;
1060 break;
1061 case STATE_DEV_UNCONNECTED:
1062 case STATE_DEV_CONNECTED:
1063 spin_unlock_irq (&dev->lock);
1064 DBG (dev, "%s wait\n", __func__);
1065
1066 /* wait for events */
1067 retval = wait_event_interruptible (dev->wait,
1068 dev->ev_next != 0);
1069 if (retval < 0)
1070 return retval;
1071 spin_lock_irq (&dev->lock);
1072 goto scan;
1073 }
1074
1075 done:
1076 spin_unlock_irq (&dev->lock);
1077 return retval;
1078 }
1079
1080 static struct usb_gadgetfs_event *
next_event(struct dev_data * dev,enum usb_gadgetfs_event_type type)1081 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1082 {
1083 struct usb_gadgetfs_event *event;
1084 unsigned i;
1085
1086 switch (type) {
1087 /* these events purge the queue */
1088 case GADGETFS_DISCONNECT:
1089 if (dev->state == STATE_DEV_SETUP)
1090 dev->setup_abort = 1;
1091 // FALL THROUGH
1092 case GADGETFS_CONNECT:
1093 dev->ev_next = 0;
1094 break;
1095 case GADGETFS_SETUP: /* previous request timed out */
1096 case GADGETFS_SUSPEND: /* same effect */
1097 /* these events can't be repeated */
1098 for (i = 0; i != dev->ev_next; i++) {
1099 if (dev->event [i].type != type)
1100 continue;
1101 DBG(dev, "discard old event[%d] %d\n", i, type);
1102 dev->ev_next--;
1103 if (i == dev->ev_next)
1104 break;
1105 /* indices start at zero, for simplicity */
1106 memmove (&dev->event [i], &dev->event [i + 1],
1107 sizeof (struct usb_gadgetfs_event)
1108 * (dev->ev_next - i));
1109 }
1110 break;
1111 default:
1112 BUG ();
1113 }
1114 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1115 event = &dev->event [dev->ev_next++];
1116 BUG_ON (dev->ev_next > N_EVENT);
1117 memset (event, 0, sizeof *event);
1118 event->type = type;
1119 return event;
1120 }
1121
1122 static ssize_t
ep0_write(struct file * fd,const char __user * buf,size_t len,loff_t * ptr)1123 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1124 {
1125 struct dev_data *dev = fd->private_data;
1126 ssize_t retval = -ESRCH;
1127
1128 /* report fd mode change before acting on it */
1129 if (dev->setup_abort) {
1130 dev->setup_abort = 0;
1131 retval = -EIDRM;
1132
1133 /* data and/or status stage for control request */
1134 } else if (dev->state == STATE_DEV_SETUP) {
1135
1136 len = min_t(size_t, len, dev->setup_wLength);
1137 if (dev->setup_in) {
1138 retval = setup_req (dev->gadget->ep0, dev->req, len);
1139 if (retval == 0) {
1140 dev->state = STATE_DEV_CONNECTED;
1141 ++dev->udc_usage;
1142 spin_unlock_irq (&dev->lock);
1143 if (copy_from_user (dev->req->buf, buf, len))
1144 retval = -EFAULT;
1145 else {
1146 if (len < dev->setup_wLength)
1147 dev->req->zero = 1;
1148 retval = usb_ep_queue (
1149 dev->gadget->ep0, dev->req,
1150 GFP_KERNEL);
1151 }
1152 spin_lock_irq(&dev->lock);
1153 --dev->udc_usage;
1154 if (retval < 0) {
1155 clean_req (dev->gadget->ep0, dev->req);
1156 } else
1157 retval = len;
1158
1159 return retval;
1160 }
1161
1162 /* can stall some OUT transfers */
1163 } else if (dev->setup_can_stall) {
1164 VDEBUG(dev, "ep0out stall\n");
1165 (void) usb_ep_set_halt (dev->gadget->ep0);
1166 retval = -EL2HLT;
1167 dev->state = STATE_DEV_CONNECTED;
1168 } else {
1169 DBG(dev, "bogus ep0out stall!\n");
1170 }
1171 } else
1172 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1173
1174 return retval;
1175 }
1176
1177 static int
ep0_fasync(int f,struct file * fd,int on)1178 ep0_fasync (int f, struct file *fd, int on)
1179 {
1180 struct dev_data *dev = fd->private_data;
1181 // caller must F_SETOWN before signal delivery happens
1182 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1183 return fasync_helper (f, fd, on, &dev->fasync);
1184 }
1185
1186 static struct usb_gadget_driver gadgetfs_driver;
1187
1188 static int
dev_release(struct inode * inode,struct file * fd)1189 dev_release (struct inode *inode, struct file *fd)
1190 {
1191 struct dev_data *dev = fd->private_data;
1192
1193 /* closing ep0 === shutdown all */
1194
1195 usb_gadget_unregister_driver (&gadgetfs_driver);
1196
1197 /* at this point "good" hardware has disconnected the
1198 * device from USB; the host won't see it any more.
1199 * alternatively, all host requests will time out.
1200 */
1201
1202 kfree (dev->buf);
1203 dev->buf = NULL;
1204
1205 /* other endpoints were all decoupled from this device */
1206 spin_lock_irq(&dev->lock);
1207 dev->state = STATE_DEV_DISABLED;
1208 spin_unlock_irq(&dev->lock);
1209
1210 put_dev (dev);
1211 return 0;
1212 }
1213
1214 static unsigned int
ep0_poll(struct file * fd,poll_table * wait)1215 ep0_poll (struct file *fd, poll_table *wait)
1216 {
1217 struct dev_data *dev = fd->private_data;
1218 int mask = 0;
1219
1220 if (dev->state <= STATE_DEV_OPENED)
1221 return DEFAULT_POLLMASK;
1222
1223 poll_wait(fd, &dev->wait, wait);
1224
1225 spin_lock_irq (&dev->lock);
1226
1227 /* report fd mode change before acting on it */
1228 if (dev->setup_abort) {
1229 dev->setup_abort = 0;
1230 mask = POLLHUP;
1231 goto out;
1232 }
1233
1234 if (dev->state == STATE_DEV_SETUP) {
1235 if (dev->setup_in || dev->setup_can_stall)
1236 mask = POLLOUT;
1237 } else {
1238 if (dev->ev_next != 0)
1239 mask = POLLIN;
1240 }
1241 out:
1242 spin_unlock_irq(&dev->lock);
1243 return mask;
1244 }
1245
dev_ioctl(struct file * fd,unsigned code,unsigned long value)1246 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1247 {
1248 struct dev_data *dev = fd->private_data;
1249 struct usb_gadget *gadget = dev->gadget;
1250 long ret = -ENOTTY;
1251
1252 spin_lock_irq(&dev->lock);
1253 if (dev->state == STATE_DEV_OPENED ||
1254 dev->state == STATE_DEV_UNBOUND) {
1255 /* Not bound to a UDC */
1256 } else if (gadget->ops->ioctl) {
1257 ++dev->udc_usage;
1258 spin_unlock_irq(&dev->lock);
1259
1260 ret = gadget->ops->ioctl (gadget, code, value);
1261
1262 spin_lock_irq(&dev->lock);
1263 --dev->udc_usage;
1264 }
1265 spin_unlock_irq(&dev->lock);
1266
1267 return ret;
1268 }
1269
1270 /*----------------------------------------------------------------------*/
1271
1272 /* The in-kernel gadget driver handles most ep0 issues, in particular
1273 * enumerating the single configuration (as provided from user space).
1274 *
1275 * Unrecognized ep0 requests may be handled in user space.
1276 */
1277
make_qualifier(struct dev_data * dev)1278 static void make_qualifier (struct dev_data *dev)
1279 {
1280 struct usb_qualifier_descriptor qual;
1281 struct usb_device_descriptor *desc;
1282
1283 qual.bLength = sizeof qual;
1284 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1285 qual.bcdUSB = cpu_to_le16 (0x0200);
1286
1287 desc = dev->dev;
1288 qual.bDeviceClass = desc->bDeviceClass;
1289 qual.bDeviceSubClass = desc->bDeviceSubClass;
1290 qual.bDeviceProtocol = desc->bDeviceProtocol;
1291
1292 /* assumes ep0 uses the same value for both speeds ... */
1293 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1294
1295 qual.bNumConfigurations = 1;
1296 qual.bRESERVED = 0;
1297
1298 memcpy (dev->rbuf, &qual, sizeof qual);
1299 }
1300
1301 static int
config_buf(struct dev_data * dev,u8 type,unsigned index)1302 config_buf (struct dev_data *dev, u8 type, unsigned index)
1303 {
1304 int len;
1305 int hs = 0;
1306
1307 /* only one configuration */
1308 if (index > 0)
1309 return -EINVAL;
1310
1311 if (gadget_is_dualspeed(dev->gadget)) {
1312 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1313 if (type == USB_DT_OTHER_SPEED_CONFIG)
1314 hs = !hs;
1315 }
1316 if (hs) {
1317 dev->req->buf = dev->hs_config;
1318 len = le16_to_cpu(dev->hs_config->wTotalLength);
1319 } else {
1320 dev->req->buf = dev->config;
1321 len = le16_to_cpu(dev->config->wTotalLength);
1322 }
1323 ((u8 *)dev->req->buf) [1] = type;
1324 return len;
1325 }
1326
1327 static int
gadgetfs_setup(struct usb_gadget * gadget,const struct usb_ctrlrequest * ctrl)1328 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1329 {
1330 struct dev_data *dev = get_gadget_data (gadget);
1331 struct usb_request *req = dev->req;
1332 int value = -EOPNOTSUPP;
1333 struct usb_gadgetfs_event *event;
1334 u16 w_value = le16_to_cpu(ctrl->wValue);
1335 u16 w_length = le16_to_cpu(ctrl->wLength);
1336
1337 if (w_length > RBUF_SIZE) {
1338 if (ctrl->bRequestType & USB_DIR_IN) {
1339 /* Cast away the const, we are going to overwrite on purpose. */
1340 __le16 *temp = (__le16 *)&ctrl->wLength;
1341
1342 *temp = cpu_to_le16(RBUF_SIZE);
1343 w_length = RBUF_SIZE;
1344 } else {
1345 return value;
1346 }
1347 }
1348
1349 spin_lock (&dev->lock);
1350 dev->setup_abort = 0;
1351 if (dev->state == STATE_DEV_UNCONNECTED) {
1352 if (gadget_is_dualspeed(gadget)
1353 && gadget->speed == USB_SPEED_HIGH
1354 && dev->hs_config == NULL) {
1355 spin_unlock(&dev->lock);
1356 ERROR (dev, "no high speed config??\n");
1357 return -EINVAL;
1358 }
1359
1360 dev->state = STATE_DEV_CONNECTED;
1361
1362 INFO (dev, "connected\n");
1363 event = next_event (dev, GADGETFS_CONNECT);
1364 event->u.speed = gadget->speed;
1365 ep0_readable (dev);
1366
1367 /* host may have given up waiting for response. we can miss control
1368 * requests handled lower down (device/endpoint status and features);
1369 * then ep0_{read,write} will report the wrong status. controller
1370 * driver will have aborted pending i/o.
1371 */
1372 } else if (dev->state == STATE_DEV_SETUP)
1373 dev->setup_abort = 1;
1374
1375 req->buf = dev->rbuf;
1376 req->context = NULL;
1377 switch (ctrl->bRequest) {
1378
1379 case USB_REQ_GET_DESCRIPTOR:
1380 if (ctrl->bRequestType != USB_DIR_IN)
1381 goto unrecognized;
1382 switch (w_value >> 8) {
1383
1384 case USB_DT_DEVICE:
1385 value = min (w_length, (u16) sizeof *dev->dev);
1386 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1387 req->buf = dev->dev;
1388 break;
1389 case USB_DT_DEVICE_QUALIFIER:
1390 if (!dev->hs_config)
1391 break;
1392 value = min (w_length, (u16)
1393 sizeof (struct usb_qualifier_descriptor));
1394 make_qualifier (dev);
1395 break;
1396 case USB_DT_OTHER_SPEED_CONFIG:
1397 // FALLTHROUGH
1398 case USB_DT_CONFIG:
1399 value = config_buf (dev,
1400 w_value >> 8,
1401 w_value & 0xff);
1402 if (value >= 0)
1403 value = min (w_length, (u16) value);
1404 break;
1405 case USB_DT_STRING:
1406 goto unrecognized;
1407
1408 default: // all others are errors
1409 break;
1410 }
1411 break;
1412
1413 /* currently one config, two speeds */
1414 case USB_REQ_SET_CONFIGURATION:
1415 if (ctrl->bRequestType != 0)
1416 goto unrecognized;
1417 if (0 == (u8) w_value) {
1418 value = 0;
1419 dev->current_config = 0;
1420 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1421 // user mode expected to disable endpoints
1422 } else {
1423 u8 config, power;
1424
1425 if (gadget_is_dualspeed(gadget)
1426 && gadget->speed == USB_SPEED_HIGH) {
1427 config = dev->hs_config->bConfigurationValue;
1428 power = dev->hs_config->bMaxPower;
1429 } else {
1430 config = dev->config->bConfigurationValue;
1431 power = dev->config->bMaxPower;
1432 }
1433
1434 if (config == (u8) w_value) {
1435 value = 0;
1436 dev->current_config = config;
1437 usb_gadget_vbus_draw(gadget, 2 * power);
1438 }
1439 }
1440
1441 /* report SET_CONFIGURATION like any other control request,
1442 * except that usermode may not stall this. the next
1443 * request mustn't be allowed start until this finishes:
1444 * endpoints and threads set up, etc.
1445 *
1446 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1447 * has bad/racey automagic that prevents synchronizing here.
1448 * even kernel mode drivers often miss them.
1449 */
1450 if (value == 0) {
1451 INFO (dev, "configuration #%d\n", dev->current_config);
1452 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1453 if (dev->usermode_setup) {
1454 dev->setup_can_stall = 0;
1455 goto delegate;
1456 }
1457 }
1458 break;
1459
1460 #ifndef CONFIG_USB_PXA25X
1461 /* PXA automagically handles this request too */
1462 case USB_REQ_GET_CONFIGURATION:
1463 if (ctrl->bRequestType != 0x80)
1464 goto unrecognized;
1465 *(u8 *)req->buf = dev->current_config;
1466 value = min (w_length, (u16) 1);
1467 break;
1468 #endif
1469
1470 default:
1471 unrecognized:
1472 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1473 dev->usermode_setup ? "delegate" : "fail",
1474 ctrl->bRequestType, ctrl->bRequest,
1475 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1476
1477 /* if there's an ep0 reader, don't stall */
1478 if (dev->usermode_setup) {
1479 dev->setup_can_stall = 1;
1480 delegate:
1481 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1482 ? 1 : 0;
1483 dev->setup_wLength = w_length;
1484 dev->setup_out_ready = 0;
1485 dev->setup_out_error = 0;
1486 value = 0;
1487
1488 /* read DATA stage for OUT right away */
1489 if (unlikely (!dev->setup_in && w_length)) {
1490 value = setup_req (gadget->ep0, dev->req,
1491 w_length);
1492 if (value < 0)
1493 break;
1494
1495 ++dev->udc_usage;
1496 spin_unlock (&dev->lock);
1497 value = usb_ep_queue (gadget->ep0, dev->req,
1498 GFP_KERNEL);
1499 spin_lock (&dev->lock);
1500 --dev->udc_usage;
1501 if (value < 0) {
1502 clean_req (gadget->ep0, dev->req);
1503 break;
1504 }
1505
1506 /* we can't currently stall these */
1507 dev->setup_can_stall = 0;
1508 }
1509
1510 /* state changes when reader collects event */
1511 event = next_event (dev, GADGETFS_SETUP);
1512 event->u.setup = *ctrl;
1513 ep0_readable (dev);
1514 spin_unlock (&dev->lock);
1515 return 0;
1516 }
1517 }
1518
1519 /* proceed with data transfer and status phases? */
1520 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1521 req->length = value;
1522 req->zero = value < w_length;
1523
1524 ++dev->udc_usage;
1525 spin_unlock (&dev->lock);
1526 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL);
1527 spin_lock(&dev->lock);
1528 --dev->udc_usage;
1529 spin_unlock(&dev->lock);
1530 if (value < 0) {
1531 DBG (dev, "ep_queue --> %d\n", value);
1532 req->status = 0;
1533 }
1534 return value;
1535 }
1536
1537 /* device stalls when value < 0 */
1538 spin_unlock (&dev->lock);
1539 return value;
1540 }
1541
destroy_ep_files(struct dev_data * dev)1542 static void destroy_ep_files (struct dev_data *dev)
1543 {
1544 DBG (dev, "%s %d\n", __func__, dev->state);
1545
1546 /* dev->state must prevent interference */
1547 spin_lock_irq (&dev->lock);
1548 while (!list_empty(&dev->epfiles)) {
1549 struct ep_data *ep;
1550 struct inode *parent;
1551 struct dentry *dentry;
1552
1553 /* break link to FS */
1554 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1555 list_del_init (&ep->epfiles);
1556 spin_unlock_irq (&dev->lock);
1557
1558 dentry = ep->dentry;
1559 ep->dentry = NULL;
1560 parent = d_inode(dentry->d_parent);
1561
1562 /* break link to controller */
1563 mutex_lock(&ep->lock);
1564 if (ep->state == STATE_EP_ENABLED)
1565 (void) usb_ep_disable (ep->ep);
1566 ep->state = STATE_EP_UNBOUND;
1567 usb_ep_free_request (ep->ep, ep->req);
1568 ep->ep = NULL;
1569 mutex_unlock(&ep->lock);
1570
1571 wake_up (&ep->wait);
1572 put_ep (ep);
1573
1574 /* break link to dcache */
1575 mutex_lock (&parent->i_mutex);
1576 d_delete (dentry);
1577 dput (dentry);
1578 mutex_unlock (&parent->i_mutex);
1579
1580 spin_lock_irq (&dev->lock);
1581 }
1582 spin_unlock_irq (&dev->lock);
1583 }
1584
1585
1586 static struct dentry *
1587 gadgetfs_create_file (struct super_block *sb, char const *name,
1588 void *data, const struct file_operations *fops);
1589
activate_ep_files(struct dev_data * dev)1590 static int activate_ep_files (struct dev_data *dev)
1591 {
1592 struct usb_ep *ep;
1593 struct ep_data *data;
1594
1595 gadget_for_each_ep (ep, dev->gadget) {
1596
1597 data = kzalloc(sizeof(*data), GFP_KERNEL);
1598 if (!data)
1599 goto enomem0;
1600 data->state = STATE_EP_DISABLED;
1601 mutex_init(&data->lock);
1602 init_waitqueue_head (&data->wait);
1603
1604 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1605 atomic_set (&data->count, 1);
1606 data->dev = dev;
1607 get_dev (dev);
1608
1609 data->ep = ep;
1610 ep->driver_data = data;
1611
1612 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1613 if (!data->req)
1614 goto enomem1;
1615
1616 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1617 data, &ep_io_operations);
1618 if (!data->dentry)
1619 goto enomem2;
1620 list_add_tail (&data->epfiles, &dev->epfiles);
1621 }
1622 return 0;
1623
1624 enomem2:
1625 usb_ep_free_request (ep, data->req);
1626 enomem1:
1627 put_dev (dev);
1628 kfree (data);
1629 enomem0:
1630 DBG (dev, "%s enomem\n", __func__);
1631 destroy_ep_files (dev);
1632 return -ENOMEM;
1633 }
1634
1635 static void
gadgetfs_unbind(struct usb_gadget * gadget)1636 gadgetfs_unbind (struct usb_gadget *gadget)
1637 {
1638 struct dev_data *dev = get_gadget_data (gadget);
1639
1640 DBG (dev, "%s\n", __func__);
1641
1642 spin_lock_irq (&dev->lock);
1643 dev->state = STATE_DEV_UNBOUND;
1644 while (dev->udc_usage > 0) {
1645 spin_unlock_irq(&dev->lock);
1646 usleep_range(1000, 2000);
1647 spin_lock_irq(&dev->lock);
1648 }
1649 spin_unlock_irq (&dev->lock);
1650
1651 destroy_ep_files (dev);
1652 gadget->ep0->driver_data = NULL;
1653 set_gadget_data (gadget, NULL);
1654
1655 /* we've already been disconnected ... no i/o is active */
1656 if (dev->req)
1657 usb_ep_free_request (gadget->ep0, dev->req);
1658 DBG (dev, "%s done\n", __func__);
1659 put_dev (dev);
1660 }
1661
1662 static struct dev_data *the_device;
1663
gadgetfs_bind(struct usb_gadget * gadget,struct usb_gadget_driver * driver)1664 static int gadgetfs_bind(struct usb_gadget *gadget,
1665 struct usb_gadget_driver *driver)
1666 {
1667 struct dev_data *dev = the_device;
1668
1669 if (!dev)
1670 return -ESRCH;
1671 if (0 != strcmp (CHIP, gadget->name)) {
1672 pr_err("%s expected %s controller not %s\n",
1673 shortname, CHIP, gadget->name);
1674 return -ENODEV;
1675 }
1676
1677 set_gadget_data (gadget, dev);
1678 dev->gadget = gadget;
1679 gadget->ep0->driver_data = dev;
1680
1681 /* preallocate control response and buffer */
1682 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1683 if (!dev->req)
1684 goto enomem;
1685 dev->req->context = NULL;
1686 dev->req->complete = epio_complete;
1687
1688 if (activate_ep_files (dev) < 0)
1689 goto enomem;
1690
1691 INFO (dev, "bound to %s driver\n", gadget->name);
1692 spin_lock_irq(&dev->lock);
1693 dev->state = STATE_DEV_UNCONNECTED;
1694 spin_unlock_irq(&dev->lock);
1695 get_dev (dev);
1696 return 0;
1697
1698 enomem:
1699 gadgetfs_unbind (gadget);
1700 return -ENOMEM;
1701 }
1702
1703 static void
gadgetfs_disconnect(struct usb_gadget * gadget)1704 gadgetfs_disconnect (struct usb_gadget *gadget)
1705 {
1706 struct dev_data *dev = get_gadget_data (gadget);
1707 unsigned long flags;
1708
1709 spin_lock_irqsave (&dev->lock, flags);
1710 if (dev->state == STATE_DEV_UNCONNECTED)
1711 goto exit;
1712 dev->state = STATE_DEV_UNCONNECTED;
1713
1714 INFO (dev, "disconnected\n");
1715 next_event (dev, GADGETFS_DISCONNECT);
1716 ep0_readable (dev);
1717 exit:
1718 spin_unlock_irqrestore (&dev->lock, flags);
1719 }
1720
1721 static void
gadgetfs_suspend(struct usb_gadget * gadget)1722 gadgetfs_suspend (struct usb_gadget *gadget)
1723 {
1724 struct dev_data *dev = get_gadget_data (gadget);
1725 unsigned long flags;
1726
1727 INFO (dev, "suspended from state %d\n", dev->state);
1728 spin_lock_irqsave(&dev->lock, flags);
1729 switch (dev->state) {
1730 case STATE_DEV_SETUP: // VERY odd... host died??
1731 case STATE_DEV_CONNECTED:
1732 case STATE_DEV_UNCONNECTED:
1733 next_event (dev, GADGETFS_SUSPEND);
1734 ep0_readable (dev);
1735 /* FALLTHROUGH */
1736 default:
1737 break;
1738 }
1739 spin_unlock_irqrestore(&dev->lock, flags);
1740 }
1741
1742 static struct usb_gadget_driver gadgetfs_driver = {
1743 .function = (char *) driver_desc,
1744 .bind = gadgetfs_bind,
1745 .unbind = gadgetfs_unbind,
1746 .setup = gadgetfs_setup,
1747 .reset = gadgetfs_disconnect,
1748 .disconnect = gadgetfs_disconnect,
1749 .suspend = gadgetfs_suspend,
1750
1751 .driver = {
1752 .name = (char *) shortname,
1753 },
1754 };
1755
1756 /*----------------------------------------------------------------------*/
1757
gadgetfs_nop(struct usb_gadget * arg)1758 static void gadgetfs_nop(struct usb_gadget *arg) { }
1759
gadgetfs_probe(struct usb_gadget * gadget,struct usb_gadget_driver * driver)1760 static int gadgetfs_probe(struct usb_gadget *gadget,
1761 struct usb_gadget_driver *driver)
1762 {
1763 CHIP = gadget->name;
1764 return -EISNAM;
1765 }
1766
1767 static struct usb_gadget_driver probe_driver = {
1768 .max_speed = USB_SPEED_HIGH,
1769 .bind = gadgetfs_probe,
1770 .unbind = gadgetfs_nop,
1771 .setup = (void *)gadgetfs_nop,
1772 .disconnect = gadgetfs_nop,
1773 .driver = {
1774 .name = "nop",
1775 },
1776 };
1777
1778
1779 /* DEVICE INITIALIZATION
1780 *
1781 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1782 * status = write (fd, descriptors, sizeof descriptors)
1783 *
1784 * That write establishes the device configuration, so the kernel can
1785 * bind to the controller ... guaranteeing it can handle enumeration
1786 * at all necessary speeds. Descriptor order is:
1787 *
1788 * . message tag (u32, host order) ... for now, must be zero; it
1789 * would change to support features like multi-config devices
1790 * . full/low speed config ... all wTotalLength bytes (with interface,
1791 * class, altsetting, endpoint, and other descriptors)
1792 * . high speed config ... all descriptors, for high speed operation;
1793 * this one's optional except for high-speed hardware
1794 * . device descriptor
1795 *
1796 * Endpoints are not yet enabled. Drivers must wait until device
1797 * configuration and interface altsetting changes create
1798 * the need to configure (or unconfigure) them.
1799 *
1800 * After initialization, the device stays active for as long as that
1801 * $CHIP file is open. Events must then be read from that descriptor,
1802 * such as configuration notifications.
1803 */
1804
is_valid_config(struct usb_config_descriptor * config,unsigned int total)1805 static int is_valid_config(struct usb_config_descriptor *config,
1806 unsigned int total)
1807 {
1808 return config->bDescriptorType == USB_DT_CONFIG
1809 && config->bLength == USB_DT_CONFIG_SIZE
1810 && total >= USB_DT_CONFIG_SIZE
1811 && config->bConfigurationValue != 0
1812 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1813 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1814 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1815 /* FIXME check lengths: walk to end */
1816 }
1817
1818 static ssize_t
dev_config(struct file * fd,const char __user * buf,size_t len,loff_t * ptr)1819 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1820 {
1821 struct dev_data *dev = fd->private_data;
1822 ssize_t value, length = len;
1823 unsigned total;
1824 u32 tag;
1825 char *kbuf;
1826
1827 spin_lock_irq(&dev->lock);
1828 if (dev->state > STATE_DEV_OPENED) {
1829 value = ep0_write(fd, buf, len, ptr);
1830 spin_unlock_irq(&dev->lock);
1831 return value;
1832 }
1833 spin_unlock_irq(&dev->lock);
1834
1835 if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
1836 (len > PAGE_SIZE * 4))
1837 return -EINVAL;
1838
1839 /* we might need to change message format someday */
1840 if (copy_from_user (&tag, buf, 4))
1841 return -EFAULT;
1842 if (tag != 0)
1843 return -EINVAL;
1844 buf += 4;
1845 length -= 4;
1846
1847 kbuf = memdup_user(buf, length);
1848 if (IS_ERR(kbuf))
1849 return PTR_ERR(kbuf);
1850
1851 spin_lock_irq (&dev->lock);
1852 value = -EINVAL;
1853 if (dev->buf) {
1854 kfree(kbuf);
1855 goto fail;
1856 }
1857 dev->buf = kbuf;
1858
1859 /* full or low speed config */
1860 dev->config = (void *) kbuf;
1861 total = le16_to_cpu(dev->config->wTotalLength);
1862 if (!is_valid_config(dev->config, total) ||
1863 total > length - USB_DT_DEVICE_SIZE)
1864 goto fail;
1865 kbuf += total;
1866 length -= total;
1867
1868 /* optional high speed config */
1869 if (kbuf [1] == USB_DT_CONFIG) {
1870 dev->hs_config = (void *) kbuf;
1871 total = le16_to_cpu(dev->hs_config->wTotalLength);
1872 if (!is_valid_config(dev->hs_config, total) ||
1873 total > length - USB_DT_DEVICE_SIZE)
1874 goto fail;
1875 kbuf += total;
1876 length -= total;
1877 } else {
1878 dev->hs_config = NULL;
1879 }
1880
1881 /* could support multiple configs, using another encoding! */
1882
1883 /* device descriptor (tweaked for paranoia) */
1884 if (length != USB_DT_DEVICE_SIZE)
1885 goto fail;
1886 dev->dev = (void *)kbuf;
1887 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1888 || dev->dev->bDescriptorType != USB_DT_DEVICE
1889 || dev->dev->bNumConfigurations != 1)
1890 goto fail;
1891 dev->dev->bNumConfigurations = 1;
1892 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1893
1894 /* triggers gadgetfs_bind(); then we can enumerate. */
1895 spin_unlock_irq (&dev->lock);
1896 if (dev->hs_config)
1897 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1898 else
1899 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1900
1901 value = usb_gadget_probe_driver(&gadgetfs_driver);
1902 if (value != 0) {
1903 kfree (dev->buf);
1904 dev->buf = NULL;
1905 } else {
1906 /* at this point "good" hardware has for the first time
1907 * let the USB the host see us. alternatively, if users
1908 * unplug/replug that will clear all the error state.
1909 *
1910 * note: everything running before here was guaranteed
1911 * to choke driver model style diagnostics. from here
1912 * on, they can work ... except in cleanup paths that
1913 * kick in after the ep0 descriptor is closed.
1914 */
1915 value = len;
1916 }
1917 return value;
1918
1919 fail:
1920 spin_unlock_irq (&dev->lock);
1921 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1922 kfree (dev->buf);
1923 dev->buf = NULL;
1924 return value;
1925 }
1926
1927 static int
dev_open(struct inode * inode,struct file * fd)1928 dev_open (struct inode *inode, struct file *fd)
1929 {
1930 struct dev_data *dev = inode->i_private;
1931 int value = -EBUSY;
1932
1933 spin_lock_irq(&dev->lock);
1934 if (dev->state == STATE_DEV_DISABLED) {
1935 dev->ev_next = 0;
1936 dev->state = STATE_DEV_OPENED;
1937 fd->private_data = dev;
1938 get_dev (dev);
1939 value = 0;
1940 }
1941 spin_unlock_irq(&dev->lock);
1942 return value;
1943 }
1944
1945 static const struct file_operations ep0_operations = {
1946 .llseek = no_llseek,
1947
1948 .open = dev_open,
1949 .read = ep0_read,
1950 .write = dev_config,
1951 .fasync = ep0_fasync,
1952 .poll = ep0_poll,
1953 .unlocked_ioctl = dev_ioctl,
1954 .release = dev_release,
1955 };
1956
1957 /*----------------------------------------------------------------------*/
1958
1959 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1960 *
1961 * Mounting the filesystem creates a controller file, used first for
1962 * device configuration then later for event monitoring.
1963 */
1964
1965
1966 /* FIXME PAM etc could set this security policy without mount options
1967 * if epfiles inherited ownership and permissons from ep0 ...
1968 */
1969
1970 static unsigned default_uid;
1971 static unsigned default_gid;
1972 static unsigned default_perm = S_IRUSR | S_IWUSR;
1973
1974 module_param (default_uid, uint, 0644);
1975 module_param (default_gid, uint, 0644);
1976 module_param (default_perm, uint, 0644);
1977
1978
1979 static struct inode *
gadgetfs_make_inode(struct super_block * sb,void * data,const struct file_operations * fops,int mode)1980 gadgetfs_make_inode (struct super_block *sb,
1981 void *data, const struct file_operations *fops,
1982 int mode)
1983 {
1984 struct inode *inode = new_inode (sb);
1985
1986 if (inode) {
1987 inode->i_ino = get_next_ino();
1988 inode->i_mode = mode;
1989 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1990 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1991 inode->i_atime = inode->i_mtime = inode->i_ctime
1992 = CURRENT_TIME;
1993 inode->i_private = data;
1994 inode->i_fop = fops;
1995 }
1996 return inode;
1997 }
1998
1999 /* creates in fs root directory, so non-renamable and non-linkable.
2000 * so inode and dentry are paired, until device reconfig.
2001 */
2002 static struct dentry *
gadgetfs_create_file(struct super_block * sb,char const * name,void * data,const struct file_operations * fops)2003 gadgetfs_create_file (struct super_block *sb, char const *name,
2004 void *data, const struct file_operations *fops)
2005 {
2006 struct dentry *dentry;
2007 struct inode *inode;
2008
2009 dentry = d_alloc_name(sb->s_root, name);
2010 if (!dentry)
2011 return NULL;
2012
2013 inode = gadgetfs_make_inode (sb, data, fops,
2014 S_IFREG | (default_perm & S_IRWXUGO));
2015 if (!inode) {
2016 dput(dentry);
2017 return NULL;
2018 }
2019 d_add (dentry, inode);
2020 return dentry;
2021 }
2022
2023 static const struct super_operations gadget_fs_operations = {
2024 .statfs = simple_statfs,
2025 .drop_inode = generic_delete_inode,
2026 };
2027
2028 static int
gadgetfs_fill_super(struct super_block * sb,void * opts,int silent)2029 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2030 {
2031 struct inode *inode;
2032 struct dev_data *dev;
2033
2034 if (the_device)
2035 return -ESRCH;
2036
2037 /* fake probe to determine $CHIP */
2038 CHIP = NULL;
2039 usb_gadget_probe_driver(&probe_driver);
2040 if (!CHIP)
2041 return -ENODEV;
2042
2043 /* superblock */
2044 sb->s_blocksize = PAGE_CACHE_SIZE;
2045 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2046 sb->s_magic = GADGETFS_MAGIC;
2047 sb->s_op = &gadget_fs_operations;
2048 sb->s_time_gran = 1;
2049
2050 /* root inode */
2051 inode = gadgetfs_make_inode (sb,
2052 NULL, &simple_dir_operations,
2053 S_IFDIR | S_IRUGO | S_IXUGO);
2054 if (!inode)
2055 goto Enomem;
2056 inode->i_op = &simple_dir_inode_operations;
2057 if (!(sb->s_root = d_make_root (inode)))
2058 goto Enomem;
2059
2060 /* the ep0 file is named after the controller we expect;
2061 * user mode code can use it for sanity checks, like we do.
2062 */
2063 dev = dev_new ();
2064 if (!dev)
2065 goto Enomem;
2066
2067 dev->sb = sb;
2068 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2069 if (!dev->dentry) {
2070 put_dev(dev);
2071 goto Enomem;
2072 }
2073
2074 /* other endpoint files are available after hardware setup,
2075 * from binding to a controller.
2076 */
2077 the_device = dev;
2078 return 0;
2079
2080 Enomem:
2081 return -ENOMEM;
2082 }
2083
2084 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2085 static struct dentry *
gadgetfs_mount(struct file_system_type * t,int flags,const char * path,void * opts)2086 gadgetfs_mount (struct file_system_type *t, int flags,
2087 const char *path, void *opts)
2088 {
2089 return mount_single (t, flags, opts, gadgetfs_fill_super);
2090 }
2091
2092 static void
gadgetfs_kill_sb(struct super_block * sb)2093 gadgetfs_kill_sb (struct super_block *sb)
2094 {
2095 kill_litter_super (sb);
2096 if (the_device) {
2097 put_dev (the_device);
2098 the_device = NULL;
2099 }
2100 }
2101
2102 /*----------------------------------------------------------------------*/
2103
2104 static struct file_system_type gadgetfs_type = {
2105 .owner = THIS_MODULE,
2106 .name = shortname,
2107 .mount = gadgetfs_mount,
2108 .kill_sb = gadgetfs_kill_sb,
2109 };
2110 MODULE_ALIAS_FS("gadgetfs");
2111
2112 /*----------------------------------------------------------------------*/
2113
init(void)2114 static int __init init (void)
2115 {
2116 int status;
2117
2118 status = register_filesystem (&gadgetfs_type);
2119 if (status == 0)
2120 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2121 shortname, driver_desc);
2122 return status;
2123 }
2124 module_init (init);
2125
cleanup(void)2126 static void __exit cleanup (void)
2127 {
2128 pr_debug ("unregister %s\n", shortname);
2129 unregister_filesystem (&gadgetfs_type);
2130 }
2131 module_exit (cleanup);
2132
2133