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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
30 #include <linux/device.h>
31 #include <linux/moduleparam.h>
32
33 #include <linux/usb/gadgetfs.h>
34 #include <linux/usb/gadget.h>
35
36
37 /*
38  * The gadgetfs API maps each endpoint to a file descriptor so that you
39  * can use standard synchronous read/write calls for I/O.  There's some
40  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
41  * drivers show how this works in practice.  You can also use AIO to
42  * eliminate I/O gaps between requests, to help when streaming data.
43  *
44  * Key parts that must be USB-specific are protocols defining how the
45  * read/write operations relate to the hardware state machines.  There
46  * are two types of files.  One type is for the device, implementing ep0.
47  * The other type is for each IN or OUT endpoint.  In both cases, the
48  * user mode driver must configure the hardware before using it.
49  *
50  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
51  *   (by writing configuration and device descriptors).  Afterwards it
52  *   may serve as a source of device events, used to handle all control
53  *   requests other than basic enumeration.
54  *
55  * - Then, after a SET_CONFIGURATION control request, ep_config() is
56  *   called when each /dev/gadget/ep* file is configured (by writing
57  *   endpoint descriptors).  Afterwards these files are used to write()
58  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
59  *   direction" request is issued (like reading an IN endpoint).
60  *
61  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
62  * not possible on all hardware.  For example, precise fault handling with
63  * respect to data left in endpoint fifos after aborted operations; or
64  * selective clearing of endpoint halts, to implement SET_INTERFACE.
65  */
66
67 #define DRIVER_DESC     "USB Gadget filesystem"
68 #define DRIVER_VERSION  "24 Aug 2004"
69
70 static const char driver_desc [] = DRIVER_DESC;
71 static const char shortname [] = "gadgetfs";
72
73 MODULE_DESCRIPTION (DRIVER_DESC);
74 MODULE_AUTHOR ("David Brownell");
75 MODULE_LICENSE ("GPL");
76
77
78 /*----------------------------------------------------------------------*/
79
80 #define GADGETFS_MAGIC          0xaee71ee7
81
82 /* /dev/gadget/$CHIP represents ep0 and the whole device */
83 enum ep0_state {
84         /* DISBLED is the initial state.
85          */
86         STATE_DEV_DISABLED = 0,
87
88         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
89          * ep0/device i/o modes and binding to the controller.  Driver
90          * must always write descriptors to initialize the device, then
91          * the device becomes UNCONNECTED until enumeration.
92          */
93         STATE_DEV_OPENED,
94
95         /* From then on, ep0 fd is in either of two basic modes:
96          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
97          * - SETUP: read/write will transfer control data and succeed;
98          *   or if "wrong direction", performs protocol stall
99          */
100         STATE_DEV_UNCONNECTED,
101         STATE_DEV_CONNECTED,
102         STATE_DEV_SETUP,
103
104         /* UNBOUND means the driver closed ep0, so the device won't be
105          * accessible again (DEV_DISABLED) until all fds are closed.
106          */
107         STATE_DEV_UNBOUND,
108 };
109
110 /* enough for the whole queue: most events invalidate others */
111 #define N_EVENT                 5
112
113 struct dev_data {
114         spinlock_t                      lock;
115         atomic_t                        count;
116         enum ep0_state                  state;          /* P: lock */
117         struct usb_gadgetfs_event       event [N_EVENT];
118         unsigned                        ev_next;
119         struct fasync_struct            *fasync;
120         u8                              current_config;
121
122         /* drivers reading ep0 MUST handle control requests (SETUP)
123          * reported that way; else the host will time out.
124          */
125         unsigned                        usermode_setup : 1,
126                                         setup_in : 1,
127                                         setup_can_stall : 1,
128                                         setup_out_ready : 1,
129                                         setup_out_error : 1,
130                                         setup_abort : 1;
131         unsigned                        setup_wLength;
132
133         /* the rest is basically write-once */
134         struct usb_config_descriptor    *config, *hs_config;
135         struct usb_device_descriptor    *dev;
136         struct usb_request              *req;
137         struct usb_gadget               *gadget;
138         struct list_head                epfiles;
139         void                            *buf;
140         wait_queue_head_t               wait;
141         struct super_block              *sb;
142         struct dentry                   *dentry;
143
144         /* except this scratch i/o buffer for ep0 */
145         u8                              rbuf [256];
146 };
147
148 static inline void get_dev (struct dev_data *data)
149 {
150         atomic_inc (&data->count);
151 }
152
153 static void put_dev (struct dev_data *data)
154 {
155         if (likely (!atomic_dec_and_test (&data->count)))
156                 return;
157         /* needs no more cleanup */
158         BUG_ON (waitqueue_active (&data->wait));
159         kfree (data);
160 }
161
162 static struct dev_data *dev_new (void)
163 {
164         struct dev_data         *dev;
165
166         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
167         if (!dev)
168                 return NULL;
169         dev->state = STATE_DEV_DISABLED;
170         atomic_set (&dev->count, 1);
171         spin_lock_init (&dev->lock);
172         INIT_LIST_HEAD (&dev->epfiles);
173         init_waitqueue_head (&dev->wait);
174         return dev;
175 }
176
177 /*----------------------------------------------------------------------*/
178
179 /* other /dev/gadget/$ENDPOINT files represent endpoints */
180 enum ep_state {
181         STATE_EP_DISABLED = 0,
182         STATE_EP_READY,
183         STATE_EP_ENABLED,
184         STATE_EP_UNBOUND,
185 };
186
187 struct ep_data {
188         struct mutex                    lock;
189         enum ep_state                   state;
190         atomic_t                        count;
191         struct dev_data                 *dev;
192         /* must hold dev->lock before accessing ep or req */
193         struct usb_ep                   *ep;
194         struct usb_request              *req;
195         ssize_t                         status;
196         char                            name [16];
197         struct usb_endpoint_descriptor  desc, hs_desc;
198         struct list_head                epfiles;
199         wait_queue_head_t               wait;
200         struct dentry                   *dentry;
201         struct inode                    *inode;
202 };
203
204 static inline void get_ep (struct ep_data *data)
205 {
206         atomic_inc (&data->count);
207 }
208
209 static void put_ep (struct ep_data *data)
210 {
211         if (likely (!atomic_dec_and_test (&data->count)))
212                 return;
213         put_dev (data->dev);
214         /* needs no more cleanup */
215         BUG_ON (!list_empty (&data->epfiles));
216         BUG_ON (waitqueue_active (&data->wait));
217         kfree (data);
218 }
219
220 /*----------------------------------------------------------------------*/
221
222 /* most "how to use the hardware" policy choices are in userspace:
223  * mapping endpoint roles (which the driver needs) to the capabilities
224  * which the usb controller has.  most of those capabilities are exposed
225  * implicitly, starting with the driver name and then endpoint names.
226  */
227
228 static const char *CHIP;
229
230 /*----------------------------------------------------------------------*/
231
232 /* NOTE:  don't use dev_printk calls before binding to the gadget
233  * at the end of ep0 configuration, or after unbind.
234  */
235
236 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
237 #define xprintk(d,level,fmt,args...) \
238         printk(level "%s: " fmt , shortname , ## args)
239
240 #ifdef DEBUG
241 #define DBG(dev,fmt,args...) \
242         xprintk(dev , KERN_DEBUG , fmt , ## args)
243 #else
244 #define DBG(dev,fmt,args...) \
245         do { } while (0)
246 #endif /* DEBUG */
247
248 #ifdef VERBOSE_DEBUG
249 #define VDEBUG  DBG
250 #else
251 #define VDEBUG(dev,fmt,args...) \
252         do { } while (0)
253 #endif /* DEBUG */
254
255 #define ERROR(dev,fmt,args...) \
256         xprintk(dev , KERN_ERR , fmt , ## args)
257 #define INFO(dev,fmt,args...) \
258         xprintk(dev , KERN_INFO , fmt , ## args)
259
260
261 /*----------------------------------------------------------------------*/
262
263 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
264  *
265  * After opening, configure non-control endpoints.  Then use normal
266  * stream read() and write() requests; and maybe ioctl() to get more
267  * precise FIFO status when recovering from cancellation.
268  */
269
270 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
271 {
272         struct ep_data  *epdata = ep->driver_data;
273
274         if (!req->context)
275                 return;
276         if (req->status)
277                 epdata->status = req->status;
278         else
279                 epdata->status = req->actual;
280         complete ((struct completion *)req->context);
281 }
282
283 /* tasklock endpoint, returning when it's connected.
284  * still need dev->lock to use epdata->ep.
285  */
286 static int
287 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
288 {
289         int     val;
290
291         if (f_flags & O_NONBLOCK) {
292                 if (!mutex_trylock(&epdata->lock))
293                         goto nonblock;
294                 if (epdata->state != STATE_EP_ENABLED) {
295                         mutex_unlock(&epdata->lock);
296 nonblock:
297                         val = -EAGAIN;
298                 } else
299                         val = 0;
300                 return val;
301         }
302
303         val = mutex_lock_interruptible(&epdata->lock);
304         if (val < 0)
305                 return val;
306
307         switch (epdata->state) {
308         case STATE_EP_ENABLED:
309                 break;
310         // case STATE_EP_DISABLED:              /* "can't happen" */
311         // case STATE_EP_READY:                 /* "can't happen" */
312         default:                                /* error! */
313                 pr_debug ("%s: ep %p not available, state %d\n",
314                                 shortname, epdata, epdata->state);
315                 // FALLTHROUGH
316         case STATE_EP_UNBOUND:                  /* clean disconnect */
317                 val = -ENODEV;
318                 mutex_unlock(&epdata->lock);
319         }
320         return val;
321 }
322
323 static ssize_t
324 ep_io (struct ep_data *epdata, void *buf, unsigned len)
325 {
326         DECLARE_COMPLETION_ONSTACK (done);
327         int value;
328
329         spin_lock_irq (&epdata->dev->lock);
330         if (likely (epdata->ep != NULL)) {
331                 struct usb_request      *req = epdata->req;
332
333                 req->context = &done;
334                 req->complete = epio_complete;
335                 req->buf = buf;
336                 req->length = len;
337                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
338         } else
339                 value = -ENODEV;
340         spin_unlock_irq (&epdata->dev->lock);
341
342         if (likely (value == 0)) {
343                 value = wait_event_interruptible (done.wait, done.done);
344                 if (value != 0) {
345                         spin_lock_irq (&epdata->dev->lock);
346                         if (likely (epdata->ep != NULL)) {
347                                 DBG (epdata->dev, "%s i/o interrupted\n",
348                                                 epdata->name);
349                                 usb_ep_dequeue (epdata->ep, epdata->req);
350                                 spin_unlock_irq (&epdata->dev->lock);
351
352                                 wait_event (done.wait, done.done);
353                                 if (epdata->status == -ECONNRESET)
354                                         epdata->status = -EINTR;
355                         } else {
356                                 spin_unlock_irq (&epdata->dev->lock);
357
358                                 DBG (epdata->dev, "endpoint gone\n");
359                                 epdata->status = -ENODEV;
360                         }
361                 }
362                 return epdata->status;
363         }
364         return value;
365 }
366
367
368 /* handle a synchronous OUT bulk/intr/iso transfer */
369 static ssize_t
370 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
371 {
372         struct ep_data          *data = fd->private_data;
373         void                    *kbuf;
374         ssize_t                 value;
375
376         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
377                 return value;
378
379         /* halt any endpoint by doing a "wrong direction" i/o call */
380         if (usb_endpoint_dir_in(&data->desc)) {
381                 if (usb_endpoint_xfer_isoc(&data->desc)) {
382                         mutex_unlock(&data->lock);
383                         return -EINVAL;
384                 }
385                 DBG (data->dev, "%s halt\n", data->name);
386                 spin_lock_irq (&data->dev->lock);
387                 if (likely (data->ep != NULL))
388                         usb_ep_set_halt (data->ep);
389                 spin_unlock_irq (&data->dev->lock);
390                 mutex_unlock(&data->lock);
391                 return -EBADMSG;
392         }
393
394         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
395
396         value = -ENOMEM;
397         kbuf = kmalloc (len, GFP_KERNEL);
398         if (unlikely (!kbuf))
399                 goto free1;
400
401         value = ep_io (data, kbuf, len);
402         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
403                 data->name, len, (int) value);
404         if (value >= 0 && copy_to_user (buf, kbuf, value))
405                 value = -EFAULT;
406
407 free1:
408         mutex_unlock(&data->lock);
409         kfree (kbuf);
410         return value;
411 }
412
413 /* handle a synchronous IN bulk/intr/iso transfer */
414 static ssize_t
415 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
416 {
417         struct ep_data          *data = fd->private_data;
418         void                    *kbuf;
419         ssize_t                 value;
420
421         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
422                 return value;
423
424         /* halt any endpoint by doing a "wrong direction" i/o call */
425         if (!usb_endpoint_dir_in(&data->desc)) {
426                 if (usb_endpoint_xfer_isoc(&data->desc)) {
427                         mutex_unlock(&data->lock);
428                         return -EINVAL;
429                 }
430                 DBG (data->dev, "%s halt\n", data->name);
431                 spin_lock_irq (&data->dev->lock);
432                 if (likely (data->ep != NULL))
433                         usb_ep_set_halt (data->ep);
434                 spin_unlock_irq (&data->dev->lock);
435                 mutex_unlock(&data->lock);
436                 return -EBADMSG;
437         }
438
439         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
440
441         value = -ENOMEM;
442         kbuf = kmalloc (len, GFP_KERNEL);
443         if (!kbuf)
444                 goto free1;
445         if (copy_from_user (kbuf, buf, len)) {
446                 value = -EFAULT;
447                 goto free1;
448         }
449
450         value = ep_io (data, kbuf, len);
451         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
452                 data->name, len, (int) value);
453 free1:
454         mutex_unlock(&data->lock);
455         kfree (kbuf);
456         return value;
457 }
458
459 static int
460 ep_release (struct inode *inode, struct file *fd)
461 {
462         struct ep_data          *data = fd->private_data;
463         int value;
464
465         value = mutex_lock_interruptible(&data->lock);
466         if (value < 0)
467                 return value;
468
469         /* clean up if this can be reopened */
470         if (data->state != STATE_EP_UNBOUND) {
471                 data->state = STATE_EP_DISABLED;
472                 data->desc.bDescriptorType = 0;
473                 data->hs_desc.bDescriptorType = 0;
474                 usb_ep_disable(data->ep);
475         }
476         mutex_unlock(&data->lock);
477         put_ep (data);
478         return 0;
479 }
480
481 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
482 {
483         struct ep_data          *data = fd->private_data;
484         int                     status;
485
486         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
487                 return status;
488
489         spin_lock_irq (&data->dev->lock);
490         if (likely (data->ep != NULL)) {
491                 switch (code) {
492                 case GADGETFS_FIFO_STATUS:
493                         status = usb_ep_fifo_status (data->ep);
494                         break;
495                 case GADGETFS_FIFO_FLUSH:
496                         usb_ep_fifo_flush (data->ep);
497                         break;
498                 case GADGETFS_CLEAR_HALT:
499                         status = usb_ep_clear_halt (data->ep);
500                         break;
501                 default:
502                         status = -ENOTTY;
503                 }
504         } else
505                 status = -ENODEV;
506         spin_unlock_irq (&data->dev->lock);
507         mutex_unlock(&data->lock);
508         return status;
509 }
510
511 /*----------------------------------------------------------------------*/
512
513 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
514
515 struct kiocb_priv {
516         struct usb_request      *req;
517         struct ep_data          *epdata;
518         struct kiocb            *iocb;
519         struct mm_struct        *mm;
520         struct work_struct      work;
521         void                    *buf;
522         const struct iovec      *iv;
523         unsigned long           nr_segs;
524         unsigned                actual;
525 };
526
527 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
528 {
529         struct kiocb_priv       *priv = iocb->private;
530         struct ep_data          *epdata;
531         int                     value;
532
533         local_irq_disable();
534         epdata = priv->epdata;
535         // spin_lock(&epdata->dev->lock);
536         if (likely(epdata && epdata->ep && priv->req))
537                 value = usb_ep_dequeue (epdata->ep, priv->req);
538         else
539                 value = -EINVAL;
540         // spin_unlock(&epdata->dev->lock);
541         local_irq_enable();
542
543         aio_put_req(iocb);
544         return value;
545 }
546
547 static ssize_t ep_copy_to_user(struct kiocb_priv *priv)
548 {
549         ssize_t                 len, total;
550         void                    *to_copy;
551         int                     i;
552
553         /* copy stuff into user buffers */
554         total = priv->actual;
555         len = 0;
556         to_copy = priv->buf;
557         for (i=0; i < priv->nr_segs; i++) {
558                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
559
560                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
561                         if (len == 0)
562                                 len = -EFAULT;
563                         break;
564                 }
565
566                 total -= this;
567                 len += this;
568                 to_copy += this;
569                 if (total == 0)
570                         break;
571         }
572
573         return len;
574 }
575
576 static void ep_user_copy_worker(struct work_struct *work)
577 {
578         struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
579         struct mm_struct *mm = priv->mm;
580         struct kiocb *iocb = priv->iocb;
581         size_t ret;
582
583         use_mm(mm);
584         ret = ep_copy_to_user(priv);
585         unuse_mm(mm);
586
587         /* completing the iocb can drop the ctx and mm, don't touch mm after */
588         aio_complete(iocb, ret, ret);
589
590         kfree(priv->buf);
591         kfree(priv);
592 }
593
594 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
595 {
596         struct kiocb            *iocb = req->context;
597         struct kiocb_priv       *priv = iocb->private;
598         struct ep_data          *epdata = priv->epdata;
599
600         /* lock against disconnect (and ideally, cancel) */
601         spin_lock(&epdata->dev->lock);
602         priv->req = NULL;
603         priv->epdata = NULL;
604
605         /* if this was a write or a read returning no data then we
606          * don't need to copy anything to userspace, so we can
607          * complete the aio request immediately.
608          */
609         if (priv->iv == NULL || unlikely(req->actual == 0)) {
610                 kfree(req->buf);
611                 kfree(priv);
612                 iocb->private = NULL;
613                 /* aio_complete() reports bytes-transferred _and_ faults */
614                 aio_complete(iocb, req->actual ? req->actual : req->status,
615                                 req->status);
616         } else {
617                 /* ep_copy_to_user() won't report both; we hide some faults */
618                 if (unlikely(0 != req->status))
619                         DBG(epdata->dev, "%s fault %d len %d\n",
620                                 ep->name, req->status, req->actual);
621
622                 priv->buf = req->buf;
623                 priv->actual = req->actual;
624                 schedule_work(&priv->work);
625         }
626         spin_unlock(&epdata->dev->lock);
627
628         usb_ep_free_request(ep, req);
629         put_ep(epdata);
630 }
631
632 static ssize_t
633 ep_aio_rwtail(
634         struct kiocb    *iocb,
635         char            *buf,
636         size_t          len,
637         struct ep_data  *epdata,
638         const struct iovec *iv,
639         unsigned long   nr_segs
640 )
641 {
642         struct kiocb_priv       *priv;
643         struct usb_request      *req;
644         ssize_t                 value;
645
646         priv = kmalloc(sizeof *priv, GFP_KERNEL);
647         if (!priv) {
648                 value = -ENOMEM;
649 fail:
650                 kfree(buf);
651                 return value;
652         }
653         iocb->private = priv;
654         priv->iocb = iocb;
655         priv->iv = iv;
656         priv->nr_segs = nr_segs;
657         INIT_WORK(&priv->work, ep_user_copy_worker);
658
659         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
660         if (unlikely(value < 0)) {
661                 kfree(priv);
662                 goto fail;
663         }
664
665         kiocb_set_cancel_fn(iocb, ep_aio_cancel);
666         get_ep(epdata);
667         priv->epdata = epdata;
668         priv->actual = 0;
669         priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
670
671         /* each kiocb is coupled to one usb_request, but we can't
672          * allocate or submit those if the host disconnected.
673          */
674         spin_lock_irq(&epdata->dev->lock);
675         if (likely(epdata->ep)) {
676                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
677                 if (likely(req)) {
678                         priv->req = req;
679                         req->buf = buf;
680                         req->length = len;
681                         req->complete = ep_aio_complete;
682                         req->context = iocb;
683                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
684                         if (unlikely(0 != value))
685                                 usb_ep_free_request(epdata->ep, req);
686                 } else
687                         value = -EAGAIN;
688         } else
689                 value = -ENODEV;
690         spin_unlock_irq(&epdata->dev->lock);
691
692         mutex_unlock(&epdata->lock);
693
694         if (unlikely(value)) {
695                 kfree(priv);
696                 put_ep(epdata);
697         } else
698                 value = -EIOCBQUEUED;
699         return value;
700 }
701
702 static ssize_t
703 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
704                 unsigned long nr_segs, loff_t o)
705 {
706         struct ep_data          *epdata = iocb->ki_filp->private_data;
707         char                    *buf;
708
709         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
710                 return -EINVAL;
711
712         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
713         if (unlikely(!buf))
714                 return -ENOMEM;
715
716         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
717 }
718
719 static ssize_t
720 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
721                 unsigned long nr_segs, loff_t o)
722 {
723         struct ep_data          *epdata = iocb->ki_filp->private_data;
724         char                    *buf;
725         size_t                  len = 0;
726         int                     i = 0;
727
728         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
729                 return -EINVAL;
730
731         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
732         if (unlikely(!buf))
733                 return -ENOMEM;
734
735         for (i=0; i < nr_segs; i++) {
736                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
737                                 iov[i].iov_len) != 0)) {
738                         kfree(buf);
739                         return -EFAULT;
740                 }
741                 len += iov[i].iov_len;
742         }
743         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
744 }
745
746 /*----------------------------------------------------------------------*/
747
748 /* used after endpoint configuration */
749 static const struct file_operations ep_io_operations = {
750         .owner =        THIS_MODULE,
751         .llseek =       no_llseek,
752
753         .read =         ep_read,
754         .write =        ep_write,
755         .unlocked_ioctl = ep_ioctl,
756         .release =      ep_release,
757
758         .aio_read =     ep_aio_read,
759         .aio_write =    ep_aio_write,
760 };
761
762 /* ENDPOINT INITIALIZATION
763  *
764  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
765  *     status = write (fd, descriptors, sizeof descriptors)
766  *
767  * That write establishes the endpoint configuration, configuring
768  * the controller to process bulk, interrupt, or isochronous transfers
769  * at the right maxpacket size, and so on.
770  *
771  * The descriptors are message type 1, identified by a host order u32
772  * at the beginning of what's written.  Descriptor order is: full/low
773  * speed descriptor, then optional high speed descriptor.
774  */
775 static ssize_t
776 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
777 {
778         struct ep_data          *data = fd->private_data;
779         struct usb_ep           *ep;
780         u32                     tag;
781         int                     value, length = len;
782
783         value = mutex_lock_interruptible(&data->lock);
784         if (value < 0)
785                 return value;
786
787         if (data->state != STATE_EP_READY) {
788                 value = -EL2HLT;
789                 goto fail;
790         }
791
792         value = len;
793         if (len < USB_DT_ENDPOINT_SIZE + 4)
794                 goto fail0;
795
796         /* we might need to change message format someday */
797         if (copy_from_user (&tag, buf, 4)) {
798                 goto fail1;
799         }
800         if (tag != 1) {
801                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
802                 goto fail0;
803         }
804         buf += 4;
805         len -= 4;
806
807         /* NOTE:  audio endpoint extensions not accepted here;
808          * just don't include the extra bytes.
809          */
810
811         /* full/low speed descriptor, then high speed */
812         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
813                 goto fail1;
814         }
815         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
816                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
817                 goto fail0;
818         if (len != USB_DT_ENDPOINT_SIZE) {
819                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
820                         goto fail0;
821                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
822                                         USB_DT_ENDPOINT_SIZE)) {
823                         goto fail1;
824                 }
825                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
826                                 || data->hs_desc.bDescriptorType
827                                         != USB_DT_ENDPOINT) {
828                         DBG(data->dev, "config %s, bad hs length or type\n",
829                                         data->name);
830                         goto fail0;
831                 }
832         }
833
834         spin_lock_irq (&data->dev->lock);
835         if (data->dev->state == STATE_DEV_UNBOUND) {
836                 value = -ENOENT;
837                 goto gone;
838         } else if ((ep = data->ep) == NULL) {
839                 value = -ENODEV;
840                 goto gone;
841         }
842         switch (data->dev->gadget->speed) {
843         case USB_SPEED_LOW:
844         case USB_SPEED_FULL:
845                 ep->desc = &data->desc;
846                 value = usb_ep_enable(ep);
847                 if (value == 0)
848                         data->state = STATE_EP_ENABLED;
849                 break;
850         case USB_SPEED_HIGH:
851                 /* fails if caller didn't provide that descriptor... */
852                 ep->desc = &data->hs_desc;
853                 value = usb_ep_enable(ep);
854                 if (value == 0)
855                         data->state = STATE_EP_ENABLED;
856                 break;
857         default:
858                 DBG(data->dev, "unconnected, %s init abandoned\n",
859                                 data->name);
860                 value = -EINVAL;
861         }
862         if (value == 0) {
863                 fd->f_op = &ep_io_operations;
864                 value = length;
865         }
866 gone:
867         spin_unlock_irq (&data->dev->lock);
868         if (value < 0) {
869 fail:
870                 data->desc.bDescriptorType = 0;
871                 data->hs_desc.bDescriptorType = 0;
872         }
873         mutex_unlock(&data->lock);
874         return value;
875 fail0:
876         value = -EINVAL;
877         goto fail;
878 fail1:
879         value = -EFAULT;
880         goto fail;
881 }
882
883 static int
884 ep_open (struct inode *inode, struct file *fd)
885 {
886         struct ep_data          *data = inode->i_private;
887         int                     value = -EBUSY;
888
889         if (mutex_lock_interruptible(&data->lock) != 0)
890                 return -EINTR;
891         spin_lock_irq (&data->dev->lock);
892         if (data->dev->state == STATE_DEV_UNBOUND)
893                 value = -ENOENT;
894         else if (data->state == STATE_EP_DISABLED) {
895                 value = 0;
896                 data->state = STATE_EP_READY;
897                 get_ep (data);
898                 fd->private_data = data;
899                 VDEBUG (data->dev, "%s ready\n", data->name);
900         } else
901                 DBG (data->dev, "%s state %d\n",
902                         data->name, data->state);
903         spin_unlock_irq (&data->dev->lock);
904         mutex_unlock(&data->lock);
905         return value;
906 }
907
908 /* used before endpoint configuration */
909 static const struct file_operations ep_config_operations = {
910         .owner =        THIS_MODULE,
911         .llseek =       no_llseek,
912
913         .open =         ep_open,
914         .write =        ep_config,
915         .release =      ep_release,
916 };
917
918 /*----------------------------------------------------------------------*/
919
920 /* EP0 IMPLEMENTATION can be partly in userspace.
921  *
922  * Drivers that use this facility receive various events, including
923  * control requests the kernel doesn't handle.  Drivers that don't
924  * use this facility may be too simple-minded for real applications.
925  */
926
927 static inline void ep0_readable (struct dev_data *dev)
928 {
929         wake_up (&dev->wait);
930         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
931 }
932
933 static void clean_req (struct usb_ep *ep, struct usb_request *req)
934 {
935         struct dev_data         *dev = ep->driver_data;
936
937         if (req->buf != dev->rbuf) {
938                 kfree(req->buf);
939                 req->buf = dev->rbuf;
940         }
941         req->complete = epio_complete;
942         dev->setup_out_ready = 0;
943 }
944
945 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
946 {
947         struct dev_data         *dev = ep->driver_data;
948         unsigned long           flags;
949         int                     free = 1;
950
951         /* for control OUT, data must still get to userspace */
952         spin_lock_irqsave(&dev->lock, flags);
953         if (!dev->setup_in) {
954                 dev->setup_out_error = (req->status != 0);
955                 if (!dev->setup_out_error)
956                         free = 0;
957                 dev->setup_out_ready = 1;
958                 ep0_readable (dev);
959         }
960
961         /* clean up as appropriate */
962         if (free && req->buf != &dev->rbuf)
963                 clean_req (ep, req);
964         req->complete = epio_complete;
965         spin_unlock_irqrestore(&dev->lock, flags);
966 }
967
968 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
969 {
970         struct dev_data *dev = ep->driver_data;
971
972         if (dev->setup_out_ready) {
973                 DBG (dev, "ep0 request busy!\n");
974                 return -EBUSY;
975         }
976         if (len > sizeof (dev->rbuf))
977                 req->buf = kmalloc(len, GFP_ATOMIC);
978         if (req->buf == NULL) {
979                 req->buf = dev->rbuf;
980                 return -ENOMEM;
981         }
982         req->complete = ep0_complete;
983         req->length = len;
984         req->zero = 0;
985         return 0;
986 }
987
988 static ssize_t
989 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
990 {
991         struct dev_data                 *dev = fd->private_data;
992         ssize_t                         retval;
993         enum ep0_state                  state;
994
995         spin_lock_irq (&dev->lock);
996
997         /* report fd mode change before acting on it */
998         if (dev->setup_abort) {
999                 dev->setup_abort = 0;
1000                 retval = -EIDRM;
1001                 goto done;
1002         }
1003
1004         /* control DATA stage */
1005         if ((state = dev->state) == STATE_DEV_SETUP) {
1006
1007                 if (dev->setup_in) {            /* stall IN */
1008                         VDEBUG(dev, "ep0in stall\n");
1009                         (void) usb_ep_set_halt (dev->gadget->ep0);
1010                         retval = -EL2HLT;
1011                         dev->state = STATE_DEV_CONNECTED;
1012
1013                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1014                         struct usb_ep           *ep = dev->gadget->ep0;
1015                         struct usb_request      *req = dev->req;
1016
1017                         if ((retval = setup_req (ep, req, 0)) == 0)
1018                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1019                         dev->state = STATE_DEV_CONNECTED;
1020
1021                         /* assume that was SET_CONFIGURATION */
1022                         if (dev->current_config) {
1023                                 unsigned power;
1024
1025                                 if (gadget_is_dualspeed(dev->gadget)
1026                                                 && (dev->gadget->speed
1027                                                         == USB_SPEED_HIGH))
1028                                         power = dev->hs_config->bMaxPower;
1029                                 else
1030                                         power = dev->config->bMaxPower;
1031                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1032                         }
1033
1034                 } else {                        /* collect OUT data */
1035                         if ((fd->f_flags & O_NONBLOCK) != 0
1036                                         && !dev->setup_out_ready) {
1037                                 retval = -EAGAIN;
1038                                 goto done;
1039                         }
1040                         spin_unlock_irq (&dev->lock);
1041                         retval = wait_event_interruptible (dev->wait,
1042                                         dev->setup_out_ready != 0);
1043
1044                         /* FIXME state could change from under us */
1045                         spin_lock_irq (&dev->lock);
1046                         if (retval)
1047                                 goto done;
1048
1049                         if (dev->state != STATE_DEV_SETUP) {
1050                                 retval = -ECANCELED;
1051                                 goto done;
1052                         }
1053                         dev->state = STATE_DEV_CONNECTED;
1054
1055                         if (dev->setup_out_error)
1056                                 retval = -EIO;
1057                         else {
1058                                 len = min (len, (size_t)dev->req->actual);
1059 // FIXME don't call this with the spinlock held ...
1060                                 if (copy_to_user (buf, dev->req->buf, len))
1061                                         retval = -EFAULT;
1062                                 else
1063                                         retval = len;
1064                                 clean_req (dev->gadget->ep0, dev->req);
1065                                 /* NOTE userspace can't yet choose to stall */
1066                         }
1067                 }
1068                 goto done;
1069         }
1070
1071         /* else normal: return event data */
1072         if (len < sizeof dev->event [0]) {
1073                 retval = -EINVAL;
1074                 goto done;
1075         }
1076         len -= len % sizeof (struct usb_gadgetfs_event);
1077         dev->usermode_setup = 1;
1078
1079 scan:
1080         /* return queued events right away */
1081         if (dev->ev_next != 0) {
1082                 unsigned                i, n;
1083
1084                 n = len / sizeof (struct usb_gadgetfs_event);
1085                 if (dev->ev_next < n)
1086                         n = dev->ev_next;
1087
1088                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1089                 for (i = 0; i < n; i++) {
1090                         if (dev->event [i].type == GADGETFS_SETUP) {
1091                                 dev->state = STATE_DEV_SETUP;
1092                                 n = i + 1;
1093                                 break;
1094                         }
1095                 }
1096                 spin_unlock_irq (&dev->lock);
1097                 len = n * sizeof (struct usb_gadgetfs_event);
1098                 if (copy_to_user (buf, &dev->event, len))
1099                         retval = -EFAULT;
1100                 else
1101                         retval = len;
1102                 if (len > 0) {
1103                         /* NOTE this doesn't guard against broken drivers;
1104                          * concurrent ep0 readers may lose events.
1105                          */
1106                         spin_lock_irq (&dev->lock);
1107                         if (dev->ev_next > n) {
1108                                 memmove(&dev->event[0], &dev->event[n],
1109                                         sizeof (struct usb_gadgetfs_event)
1110                                                 * (dev->ev_next - n));
1111                         }
1112                         dev->ev_next -= n;
1113                         spin_unlock_irq (&dev->lock);
1114                 }
1115                 return retval;
1116         }
1117         if (fd->f_flags & O_NONBLOCK) {
1118                 retval = -EAGAIN;
1119                 goto done;
1120         }
1121
1122         switch (state) {
1123         default:
1124                 DBG (dev, "fail %s, state %d\n", __func__, state);
1125                 retval = -ESRCH;
1126                 break;
1127         case STATE_DEV_UNCONNECTED:
1128         case STATE_DEV_CONNECTED:
1129                 spin_unlock_irq (&dev->lock);
1130                 DBG (dev, "%s wait\n", __func__);
1131
1132                 /* wait for events */
1133                 retval = wait_event_interruptible (dev->wait,
1134                                 dev->ev_next != 0);
1135                 if (retval < 0)
1136                         return retval;
1137                 spin_lock_irq (&dev->lock);
1138                 goto scan;
1139         }
1140
1141 done:
1142         spin_unlock_irq (&dev->lock);
1143         return retval;
1144 }
1145
1146 static struct usb_gadgetfs_event *
1147 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1148 {
1149         struct usb_gadgetfs_event       *event;
1150         unsigned                        i;
1151
1152         switch (type) {
1153         /* these events purge the queue */
1154         case GADGETFS_DISCONNECT:
1155                 if (dev->state == STATE_DEV_SETUP)
1156                         dev->setup_abort = 1;
1157                 // FALL THROUGH
1158         case GADGETFS_CONNECT:
1159                 dev->ev_next = 0;
1160                 break;
1161         case GADGETFS_SETUP:            /* previous request timed out */
1162         case GADGETFS_SUSPEND:          /* same effect */
1163                 /* these events can't be repeated */
1164                 for (i = 0; i != dev->ev_next; i++) {
1165                         if (dev->event [i].type != type)
1166                                 continue;
1167                         DBG(dev, "discard old event[%d] %d\n", i, type);
1168                         dev->ev_next--;
1169                         if (i == dev->ev_next)
1170                                 break;
1171                         /* indices start at zero, for simplicity */
1172                         memmove (&dev->event [i], &dev->event [i + 1],
1173                                 sizeof (struct usb_gadgetfs_event)
1174                                         * (dev->ev_next - i));
1175                 }
1176                 break;
1177         default:
1178                 BUG ();
1179         }
1180         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1181         event = &dev->event [dev->ev_next++];
1182         BUG_ON (dev->ev_next > N_EVENT);
1183         memset (event, 0, sizeof *event);
1184         event->type = type;
1185         return event;
1186 }
1187
1188 static ssize_t
1189 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1190 {
1191         struct dev_data         *dev = fd->private_data;
1192         ssize_t                 retval = -ESRCH;
1193
1194         spin_lock_irq (&dev->lock);
1195
1196         /* report fd mode change before acting on it */
1197         if (dev->setup_abort) {
1198                 dev->setup_abort = 0;
1199                 retval = -EIDRM;
1200
1201         /* data and/or status stage for control request */
1202         } else if (dev->state == STATE_DEV_SETUP) {
1203
1204                 /* IN DATA+STATUS caller makes len <= wLength */
1205                 if (dev->setup_in) {
1206                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1207                         if (retval == 0) {
1208                                 dev->state = STATE_DEV_CONNECTED;
1209                                 spin_unlock_irq (&dev->lock);
1210                                 if (copy_from_user (dev->req->buf, buf, len))
1211                                         retval = -EFAULT;
1212                                 else {
1213                                         if (len < dev->setup_wLength)
1214                                                 dev->req->zero = 1;
1215                                         retval = usb_ep_queue (
1216                                                 dev->gadget->ep0, dev->req,
1217                                                 GFP_KERNEL);
1218                                 }
1219                                 if (retval < 0) {
1220                                         spin_lock_irq (&dev->lock);
1221                                         clean_req (dev->gadget->ep0, dev->req);
1222                                         spin_unlock_irq (&dev->lock);
1223                                 } else
1224                                         retval = len;
1225
1226                                 return retval;
1227                         }
1228
1229                 /* can stall some OUT transfers */
1230                 } else if (dev->setup_can_stall) {
1231                         VDEBUG(dev, "ep0out stall\n");
1232                         (void) usb_ep_set_halt (dev->gadget->ep0);
1233                         retval = -EL2HLT;
1234                         dev->state = STATE_DEV_CONNECTED;
1235                 } else {
1236                         DBG(dev, "bogus ep0out stall!\n");
1237                 }
1238         } else
1239                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1240
1241         spin_unlock_irq (&dev->lock);
1242         return retval;
1243 }
1244
1245 static int
1246 ep0_fasync (int f, struct file *fd, int on)
1247 {
1248         struct dev_data         *dev = fd->private_data;
1249         // caller must F_SETOWN before signal delivery happens
1250         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1251         return fasync_helper (f, fd, on, &dev->fasync);
1252 }
1253
1254 static struct usb_gadget_driver gadgetfs_driver;
1255
1256 static int
1257 dev_release (struct inode *inode, struct file *fd)
1258 {
1259         struct dev_data         *dev = fd->private_data;
1260
1261         /* closing ep0 === shutdown all */
1262
1263         usb_gadget_unregister_driver (&gadgetfs_driver);
1264
1265         /* at this point "good" hardware has disconnected the
1266          * device from USB; the host won't see it any more.
1267          * alternatively, all host requests will time out.
1268          */
1269
1270         kfree (dev->buf);
1271         dev->buf = NULL;
1272         put_dev (dev);
1273
1274         /* other endpoints were all decoupled from this device */
1275         spin_lock_irq(&dev->lock);
1276         dev->state = STATE_DEV_DISABLED;
1277         spin_unlock_irq(&dev->lock);
1278         return 0;
1279 }
1280
1281 static unsigned int
1282 ep0_poll (struct file *fd, poll_table *wait)
1283 {
1284        struct dev_data         *dev = fd->private_data;
1285        int                     mask = 0;
1286
1287        poll_wait(fd, &dev->wait, wait);
1288
1289        spin_lock_irq (&dev->lock);
1290
1291        /* report fd mode change before acting on it */
1292        if (dev->setup_abort) {
1293                dev->setup_abort = 0;
1294                mask = POLLHUP;
1295                goto out;
1296        }
1297
1298        if (dev->state == STATE_DEV_SETUP) {
1299                if (dev->setup_in || dev->setup_can_stall)
1300                        mask = POLLOUT;
1301        } else {
1302                if (dev->ev_next != 0)
1303                        mask = POLLIN;
1304        }
1305 out:
1306        spin_unlock_irq(&dev->lock);
1307        return mask;
1308 }
1309
1310 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1311 {
1312         struct dev_data         *dev = fd->private_data;
1313         struct usb_gadget       *gadget = dev->gadget;
1314         long ret = -ENOTTY;
1315
1316         if (gadget->ops->ioctl)
1317                 ret = gadget->ops->ioctl (gadget, code, value);
1318
1319         return ret;
1320 }
1321
1322 /* used after device configuration */
1323 static const struct file_operations ep0_io_operations = {
1324         .owner =        THIS_MODULE,
1325         .llseek =       no_llseek,
1326
1327         .read =         ep0_read,
1328         .write =        ep0_write,
1329         .fasync =       ep0_fasync,
1330         .poll =         ep0_poll,
1331         .unlocked_ioctl =       dev_ioctl,
1332         .release =      dev_release,
1333 };
1334
1335 /*----------------------------------------------------------------------*/
1336
1337 /* The in-kernel gadget driver handles most ep0 issues, in particular
1338  * enumerating the single configuration (as provided from user space).
1339  *
1340  * Unrecognized ep0 requests may be handled in user space.
1341  */
1342
1343 static void make_qualifier (struct dev_data *dev)
1344 {
1345         struct usb_qualifier_descriptor         qual;
1346         struct usb_device_descriptor            *desc;
1347
1348         qual.bLength = sizeof qual;
1349         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1350         qual.bcdUSB = cpu_to_le16 (0x0200);
1351
1352         desc = dev->dev;
1353         qual.bDeviceClass = desc->bDeviceClass;
1354         qual.bDeviceSubClass = desc->bDeviceSubClass;
1355         qual.bDeviceProtocol = desc->bDeviceProtocol;
1356
1357         /* assumes ep0 uses the same value for both speeds ... */
1358         qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1359
1360         qual.bNumConfigurations = 1;
1361         qual.bRESERVED = 0;
1362
1363         memcpy (dev->rbuf, &qual, sizeof qual);
1364 }
1365
1366 static int
1367 config_buf (struct dev_data *dev, u8 type, unsigned index)
1368 {
1369         int             len;
1370         int             hs = 0;
1371
1372         /* only one configuration */
1373         if (index > 0)
1374                 return -EINVAL;
1375
1376         if (gadget_is_dualspeed(dev->gadget)) {
1377                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1378                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1379                         hs = !hs;
1380         }
1381         if (hs) {
1382                 dev->req->buf = dev->hs_config;
1383                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1384         } else {
1385                 dev->req->buf = dev->config;
1386                 len = le16_to_cpu(dev->config->wTotalLength);
1387         }
1388         ((u8 *)dev->req->buf) [1] = type;
1389         return len;
1390 }
1391
1392 static int
1393 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1394 {
1395         struct dev_data                 *dev = get_gadget_data (gadget);
1396         struct usb_request              *req = dev->req;
1397         int                             value = -EOPNOTSUPP;
1398         struct usb_gadgetfs_event       *event;
1399         u16                             w_value = le16_to_cpu(ctrl->wValue);
1400         u16                             w_length = le16_to_cpu(ctrl->wLength);
1401
1402         spin_lock (&dev->lock);
1403         dev->setup_abort = 0;
1404         if (dev->state == STATE_DEV_UNCONNECTED) {
1405                 if (gadget_is_dualspeed(gadget)
1406                                 && gadget->speed == USB_SPEED_HIGH
1407                                 && dev->hs_config == NULL) {
1408                         spin_unlock(&dev->lock);
1409                         ERROR (dev, "no high speed config??\n");
1410                         return -EINVAL;
1411                 }
1412
1413                 dev->state = STATE_DEV_CONNECTED;
1414
1415                 INFO (dev, "connected\n");
1416                 event = next_event (dev, GADGETFS_CONNECT);
1417                 event->u.speed = gadget->speed;
1418                 ep0_readable (dev);
1419
1420         /* host may have given up waiting for response.  we can miss control
1421          * requests handled lower down (device/endpoint status and features);
1422          * then ep0_{read,write} will report the wrong status. controller
1423          * driver will have aborted pending i/o.
1424          */
1425         } else if (dev->state == STATE_DEV_SETUP)
1426                 dev->setup_abort = 1;
1427
1428         req->buf = dev->rbuf;
1429         req->context = NULL;
1430         value = -EOPNOTSUPP;
1431         switch (ctrl->bRequest) {
1432
1433         case USB_REQ_GET_DESCRIPTOR:
1434                 if (ctrl->bRequestType != USB_DIR_IN)
1435                         goto unrecognized;
1436                 switch (w_value >> 8) {
1437
1438                 case USB_DT_DEVICE:
1439                         value = min (w_length, (u16) sizeof *dev->dev);
1440                         dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1441                         req->buf = dev->dev;
1442                         break;
1443                 case USB_DT_DEVICE_QUALIFIER:
1444                         if (!dev->hs_config)
1445                                 break;
1446                         value = min (w_length, (u16)
1447                                 sizeof (struct usb_qualifier_descriptor));
1448                         make_qualifier (dev);
1449                         break;
1450                 case USB_DT_OTHER_SPEED_CONFIG:
1451                         // FALLTHROUGH
1452                 case USB_DT_CONFIG:
1453                         value = config_buf (dev,
1454                                         w_value >> 8,
1455                                         w_value & 0xff);
1456                         if (value >= 0)
1457                                 value = min (w_length, (u16) value);
1458                         break;
1459                 case USB_DT_STRING:
1460                         goto unrecognized;
1461
1462                 default:                // all others are errors
1463                         break;
1464                 }
1465                 break;
1466
1467         /* currently one config, two speeds */
1468         case USB_REQ_SET_CONFIGURATION:
1469                 if (ctrl->bRequestType != 0)
1470                         goto unrecognized;
1471                 if (0 == (u8) w_value) {
1472                         value = 0;
1473                         dev->current_config = 0;
1474                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1475                         // user mode expected to disable endpoints
1476                 } else {
1477                         u8      config, power;
1478
1479                         if (gadget_is_dualspeed(gadget)
1480                                         && gadget->speed == USB_SPEED_HIGH) {
1481                                 config = dev->hs_config->bConfigurationValue;
1482                                 power = dev->hs_config->bMaxPower;
1483                         } else {
1484                                 config = dev->config->bConfigurationValue;
1485                                 power = dev->config->bMaxPower;
1486                         }
1487
1488                         if (config == (u8) w_value) {
1489                                 value = 0;
1490                                 dev->current_config = config;
1491                                 usb_gadget_vbus_draw(gadget, 2 * power);
1492                         }
1493                 }
1494
1495                 /* report SET_CONFIGURATION like any other control request,
1496                  * except that usermode may not stall this.  the next
1497                  * request mustn't be allowed start until this finishes:
1498                  * endpoints and threads set up, etc.
1499                  *
1500                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1501                  * has bad/racey automagic that prevents synchronizing here.
1502                  * even kernel mode drivers often miss them.
1503                  */
1504                 if (value == 0) {
1505                         INFO (dev, "configuration #%d\n", dev->current_config);
1506                         if (dev->usermode_setup) {
1507                                 dev->setup_can_stall = 0;
1508                                 goto delegate;
1509                         }
1510                 }
1511                 break;
1512
1513 #ifndef CONFIG_USB_GADGET_PXA25X
1514         /* PXA automagically handles this request too */
1515         case USB_REQ_GET_CONFIGURATION:
1516                 if (ctrl->bRequestType != 0x80)
1517                         goto unrecognized;
1518                 *(u8 *)req->buf = dev->current_config;
1519                 value = min (w_length, (u16) 1);
1520                 break;
1521 #endif
1522
1523         default:
1524 unrecognized:
1525                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1526                         dev->usermode_setup ? "delegate" : "fail",
1527                         ctrl->bRequestType, ctrl->bRequest,
1528                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1529
1530                 /* if there's an ep0 reader, don't stall */
1531                 if (dev->usermode_setup) {
1532                         dev->setup_can_stall = 1;
1533 delegate:
1534                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1535                                                 ? 1 : 0;
1536                         dev->setup_wLength = w_length;
1537                         dev->setup_out_ready = 0;
1538                         dev->setup_out_error = 0;
1539                         value = 0;
1540
1541                         /* read DATA stage for OUT right away */
1542                         if (unlikely (!dev->setup_in && w_length)) {
1543                                 value = setup_req (gadget->ep0, dev->req,
1544                                                         w_length);
1545                                 if (value < 0)
1546                                         break;
1547                                 value = usb_ep_queue (gadget->ep0, dev->req,
1548                                                         GFP_ATOMIC);
1549                                 if (value < 0) {
1550                                         clean_req (gadget->ep0, dev->req);
1551                                         break;
1552                                 }
1553
1554                                 /* we can't currently stall these */
1555                                 dev->setup_can_stall = 0;
1556                         }
1557
1558                         /* state changes when reader collects event */
1559                         event = next_event (dev, GADGETFS_SETUP);
1560                         event->u.setup = *ctrl;
1561                         ep0_readable (dev);
1562                         spin_unlock (&dev->lock);
1563                         return 0;
1564                 }
1565         }
1566
1567         /* proceed with data transfer and status phases? */
1568         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1569                 req->length = value;
1570                 req->zero = value < w_length;
1571                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1572                 if (value < 0) {
1573                         DBG (dev, "ep_queue --> %d\n", value);
1574                         req->status = 0;
1575                 }
1576         }
1577
1578         /* device stalls when value < 0 */
1579         spin_unlock (&dev->lock);
1580         return value;
1581 }
1582
1583 static void destroy_ep_files (struct dev_data *dev)
1584 {
1585         DBG (dev, "%s %d\n", __func__, dev->state);
1586
1587         /* dev->state must prevent interference */
1588         spin_lock_irq (&dev->lock);
1589         while (!list_empty(&dev->epfiles)) {
1590                 struct ep_data  *ep;
1591                 struct inode    *parent;
1592                 struct dentry   *dentry;
1593
1594                 /* break link to FS */
1595                 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1596                 list_del_init (&ep->epfiles);
1597                 dentry = ep->dentry;
1598                 ep->dentry = NULL;
1599                 parent = dentry->d_parent->d_inode;
1600
1601                 /* break link to controller */
1602                 if (ep->state == STATE_EP_ENABLED)
1603                         (void) usb_ep_disable (ep->ep);
1604                 ep->state = STATE_EP_UNBOUND;
1605                 usb_ep_free_request (ep->ep, ep->req);
1606                 ep->ep = NULL;
1607                 wake_up (&ep->wait);
1608                 put_ep (ep);
1609
1610                 spin_unlock_irq (&dev->lock);
1611
1612                 /* break link to dcache */
1613                 mutex_lock (&parent->i_mutex);
1614                 d_delete (dentry);
1615                 dput (dentry);
1616                 mutex_unlock (&parent->i_mutex);
1617
1618                 spin_lock_irq (&dev->lock);
1619         }
1620         spin_unlock_irq (&dev->lock);
1621 }
1622
1623
1624 static struct inode *
1625 gadgetfs_create_file (struct super_block *sb, char const *name,
1626                 void *data, const struct file_operations *fops,
1627                 struct dentry **dentry_p);
1628
1629 static int activate_ep_files (struct dev_data *dev)
1630 {
1631         struct usb_ep   *ep;
1632         struct ep_data  *data;
1633
1634         gadget_for_each_ep (ep, dev->gadget) {
1635
1636                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1637                 if (!data)
1638                         goto enomem0;
1639                 data->state = STATE_EP_DISABLED;
1640                 mutex_init(&data->lock);
1641                 init_waitqueue_head (&data->wait);
1642
1643                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1644                 atomic_set (&data->count, 1);
1645                 data->dev = dev;
1646                 get_dev (dev);
1647
1648                 data->ep = ep;
1649                 ep->driver_data = data;
1650
1651                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1652                 if (!data->req)
1653                         goto enomem1;
1654
1655                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1656                                 data, &ep_config_operations,
1657                                 &data->dentry);
1658                 if (!data->inode)
1659                         goto enomem2;
1660                 list_add_tail (&data->epfiles, &dev->epfiles);
1661         }
1662         return 0;
1663
1664 enomem2:
1665         usb_ep_free_request (ep, data->req);
1666 enomem1:
1667         put_dev (dev);
1668         kfree (data);
1669 enomem0:
1670         DBG (dev, "%s enomem\n", __func__);
1671         destroy_ep_files (dev);
1672         return -ENOMEM;
1673 }
1674
1675 static void
1676 gadgetfs_unbind (struct usb_gadget *gadget)
1677 {
1678         struct dev_data         *dev = get_gadget_data (gadget);
1679
1680         DBG (dev, "%s\n", __func__);
1681
1682         spin_lock_irq (&dev->lock);
1683         dev->state = STATE_DEV_UNBOUND;
1684         spin_unlock_irq (&dev->lock);
1685
1686         destroy_ep_files (dev);
1687         gadget->ep0->driver_data = NULL;
1688         set_gadget_data (gadget, NULL);
1689
1690         /* we've already been disconnected ... no i/o is active */
1691         if (dev->req)
1692                 usb_ep_free_request (gadget->ep0, dev->req);
1693         DBG (dev, "%s done\n", __func__);
1694         put_dev (dev);
1695 }
1696
1697 static struct dev_data          *the_device;
1698
1699 static int gadgetfs_bind(struct usb_gadget *gadget,
1700                 struct usb_gadget_driver *driver)
1701 {
1702         struct dev_data         *dev = the_device;
1703
1704         if (!dev)
1705                 return -ESRCH;
1706         if (0 != strcmp (CHIP, gadget->name)) {
1707                 pr_err("%s expected %s controller not %s\n",
1708                         shortname, CHIP, gadget->name);
1709                 return -ENODEV;
1710         }
1711
1712         set_gadget_data (gadget, dev);
1713         dev->gadget = gadget;
1714         gadget->ep0->driver_data = dev;
1715
1716         /* preallocate control response and buffer */
1717         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1718         if (!dev->req)
1719                 goto enomem;
1720         dev->req->context = NULL;
1721         dev->req->complete = epio_complete;
1722
1723         if (activate_ep_files (dev) < 0)
1724                 goto enomem;
1725
1726         INFO (dev, "bound to %s driver\n", gadget->name);
1727         spin_lock_irq(&dev->lock);
1728         dev->state = STATE_DEV_UNCONNECTED;
1729         spin_unlock_irq(&dev->lock);
1730         get_dev (dev);
1731         return 0;
1732
1733 enomem:
1734         gadgetfs_unbind (gadget);
1735         return -ENOMEM;
1736 }
1737
1738 static void
1739 gadgetfs_disconnect (struct usb_gadget *gadget)
1740 {
1741         struct dev_data         *dev = get_gadget_data (gadget);
1742         unsigned long           flags;
1743
1744         spin_lock_irqsave (&dev->lock, flags);
1745         if (dev->state == STATE_DEV_UNCONNECTED)
1746                 goto exit;
1747         dev->state = STATE_DEV_UNCONNECTED;
1748
1749         INFO (dev, "disconnected\n");
1750         next_event (dev, GADGETFS_DISCONNECT);
1751         ep0_readable (dev);
1752 exit:
1753         spin_unlock_irqrestore (&dev->lock, flags);
1754 }
1755
1756 static void
1757 gadgetfs_suspend (struct usb_gadget *gadget)
1758 {
1759         struct dev_data         *dev = get_gadget_data (gadget);
1760
1761         INFO (dev, "suspended from state %d\n", dev->state);
1762         spin_lock (&dev->lock);
1763         switch (dev->state) {
1764         case STATE_DEV_SETUP:           // VERY odd... host died??
1765         case STATE_DEV_CONNECTED:
1766         case STATE_DEV_UNCONNECTED:
1767                 next_event (dev, GADGETFS_SUSPEND);
1768                 ep0_readable (dev);
1769                 /* FALLTHROUGH */
1770         default:
1771                 break;
1772         }
1773         spin_unlock (&dev->lock);
1774 }
1775
1776 static struct usb_gadget_driver gadgetfs_driver = {
1777         .function       = (char *) driver_desc,
1778         .bind           = gadgetfs_bind,
1779         .unbind         = gadgetfs_unbind,
1780         .setup          = gadgetfs_setup,
1781         .disconnect     = gadgetfs_disconnect,
1782         .suspend        = gadgetfs_suspend,
1783
1784         .driver = {
1785                 .name           = (char *) shortname,
1786         },
1787 };
1788
1789 /*----------------------------------------------------------------------*/
1790
1791 static void gadgetfs_nop(struct usb_gadget *arg) { }
1792
1793 static int gadgetfs_probe(struct usb_gadget *gadget,
1794                 struct usb_gadget_driver *driver)
1795 {
1796         CHIP = gadget->name;
1797         return -EISNAM;
1798 }
1799
1800 static struct usb_gadget_driver probe_driver = {
1801         .max_speed      = USB_SPEED_HIGH,
1802         .bind           = gadgetfs_probe,
1803         .unbind         = gadgetfs_nop,
1804         .setup          = (void *)gadgetfs_nop,
1805         .disconnect     = gadgetfs_nop,
1806         .driver = {
1807                 .name           = "nop",
1808         },
1809 };
1810
1811
1812 /* DEVICE INITIALIZATION
1813  *
1814  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1815  *     status = write (fd, descriptors, sizeof descriptors)
1816  *
1817  * That write establishes the device configuration, so the kernel can
1818  * bind to the controller ... guaranteeing it can handle enumeration
1819  * at all necessary speeds.  Descriptor order is:
1820  *
1821  * . message tag (u32, host order) ... for now, must be zero; it
1822  *      would change to support features like multi-config devices
1823  * . full/low speed config ... all wTotalLength bytes (with interface,
1824  *      class, altsetting, endpoint, and other descriptors)
1825  * . high speed config ... all descriptors, for high speed operation;
1826  *      this one's optional except for high-speed hardware
1827  * . device descriptor
1828  *
1829  * Endpoints are not yet enabled. Drivers must wait until device
1830  * configuration and interface altsetting changes create
1831  * the need to configure (or unconfigure) them.
1832  *
1833  * After initialization, the device stays active for as long as that
1834  * $CHIP file is open.  Events must then be read from that descriptor,
1835  * such as configuration notifications.
1836  */
1837
1838 static int is_valid_config (struct usb_config_descriptor *config)
1839 {
1840         return config->bDescriptorType == USB_DT_CONFIG
1841                 && config->bLength == USB_DT_CONFIG_SIZE
1842                 && config->bConfigurationValue != 0
1843                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1844                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1845         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1846         /* FIXME check lengths: walk to end */
1847 }
1848
1849 static ssize_t
1850 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1851 {
1852         struct dev_data         *dev = fd->private_data;
1853         ssize_t                 value = len, length = len;
1854         unsigned                total;
1855         u32                     tag;
1856         char                    *kbuf;
1857
1858         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1859                 return -EINVAL;
1860
1861         /* we might need to change message format someday */
1862         if (copy_from_user (&tag, buf, 4))
1863                 return -EFAULT;
1864         if (tag != 0)
1865                 return -EINVAL;
1866         buf += 4;
1867         length -= 4;
1868
1869         kbuf = memdup_user(buf, length);
1870         if (IS_ERR(kbuf))
1871                 return PTR_ERR(kbuf);
1872
1873         spin_lock_irq (&dev->lock);
1874         value = -EINVAL;
1875         if (dev->buf)
1876                 goto fail;
1877         dev->buf = kbuf;
1878
1879         /* full or low speed config */
1880         dev->config = (void *) kbuf;
1881         total = le16_to_cpu(dev->config->wTotalLength);
1882         if (!is_valid_config (dev->config) || total >= length)
1883                 goto fail;
1884         kbuf += total;
1885         length -= total;
1886
1887         /* optional high speed config */
1888         if (kbuf [1] == USB_DT_CONFIG) {
1889                 dev->hs_config = (void *) kbuf;
1890                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1891                 if (!is_valid_config (dev->hs_config) || total >= length)
1892                         goto fail;
1893                 kbuf += total;
1894                 length -= total;
1895         }
1896
1897         /* could support multiple configs, using another encoding! */
1898
1899         /* device descriptor (tweaked for paranoia) */
1900         if (length != USB_DT_DEVICE_SIZE)
1901                 goto fail;
1902         dev->dev = (void *)kbuf;
1903         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1904                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1905                         || dev->dev->bNumConfigurations != 1)
1906                 goto fail;
1907         dev->dev->bNumConfigurations = 1;
1908         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1909
1910         /* triggers gadgetfs_bind(); then we can enumerate. */
1911         spin_unlock_irq (&dev->lock);
1912         if (dev->hs_config)
1913                 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1914         else
1915                 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1916
1917         value = usb_gadget_probe_driver(&gadgetfs_driver);
1918         if (value != 0) {
1919                 kfree (dev->buf);
1920                 dev->buf = NULL;
1921         } else {
1922                 /* at this point "good" hardware has for the first time
1923                  * let the USB the host see us.  alternatively, if users
1924                  * unplug/replug that will clear all the error state.
1925                  *
1926                  * note:  everything running before here was guaranteed
1927                  * to choke driver model style diagnostics.  from here
1928                  * on, they can work ... except in cleanup paths that
1929                  * kick in after the ep0 descriptor is closed.
1930                  */
1931                 fd->f_op = &ep0_io_operations;
1932                 value = len;
1933         }
1934         return value;
1935
1936 fail:
1937         spin_unlock_irq (&dev->lock);
1938         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1939         kfree (dev->buf);
1940         dev->buf = NULL;
1941         return value;
1942 }
1943
1944 static int
1945 dev_open (struct inode *inode, struct file *fd)
1946 {
1947         struct dev_data         *dev = inode->i_private;
1948         int                     value = -EBUSY;
1949
1950         spin_lock_irq(&dev->lock);
1951         if (dev->state == STATE_DEV_DISABLED) {
1952                 dev->ev_next = 0;
1953                 dev->state = STATE_DEV_OPENED;
1954                 fd->private_data = dev;
1955                 get_dev (dev);
1956                 value = 0;
1957         }
1958         spin_unlock_irq(&dev->lock);
1959         return value;
1960 }
1961
1962 static const struct file_operations dev_init_operations = {
1963         .owner =        THIS_MODULE,
1964         .llseek =       no_llseek,
1965
1966         .open =         dev_open,
1967         .write =        dev_config,
1968         .fasync =       ep0_fasync,
1969         .unlocked_ioctl = dev_ioctl,
1970         .release =      dev_release,
1971 };
1972
1973 /*----------------------------------------------------------------------*/
1974
1975 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1976  *
1977  * Mounting the filesystem creates a controller file, used first for
1978  * device configuration then later for event monitoring.
1979  */
1980
1981
1982 /* FIXME PAM etc could set this security policy without mount options
1983  * if epfiles inherited ownership and permissons from ep0 ...
1984  */
1985
1986 static unsigned default_uid;
1987 static unsigned default_gid;
1988 static unsigned default_perm = S_IRUSR | S_IWUSR;
1989
1990 module_param (default_uid, uint, 0644);
1991 module_param (default_gid, uint, 0644);
1992 module_param (default_perm, uint, 0644);
1993
1994
1995 static struct inode *
1996 gadgetfs_make_inode (struct super_block *sb,
1997                 void *data, const struct file_operations *fops,
1998                 int mode)
1999 {
2000         struct inode *inode = new_inode (sb);
2001
2002         if (inode) {
2003                 inode->i_ino = get_next_ino();
2004                 inode->i_mode = mode;
2005                 inode->i_uid = make_kuid(&init_user_ns, default_uid);
2006                 inode->i_gid = make_kgid(&init_user_ns, default_gid);
2007                 inode->i_atime = inode->i_mtime = inode->i_ctime
2008                                 = CURRENT_TIME;
2009                 inode->i_private = data;
2010                 inode->i_fop = fops;
2011         }
2012         return inode;
2013 }
2014
2015 /* creates in fs root directory, so non-renamable and non-linkable.
2016  * so inode and dentry are paired, until device reconfig.
2017  */
2018 static struct inode *
2019 gadgetfs_create_file (struct super_block *sb, char const *name,
2020                 void *data, const struct file_operations *fops,
2021                 struct dentry **dentry_p)
2022 {
2023         struct dentry   *dentry;
2024         struct inode    *inode;
2025
2026         dentry = d_alloc_name(sb->s_root, name);
2027         if (!dentry)
2028                 return NULL;
2029
2030         inode = gadgetfs_make_inode (sb, data, fops,
2031                         S_IFREG | (default_perm & S_IRWXUGO));
2032         if (!inode) {
2033                 dput(dentry);
2034                 return NULL;
2035         }
2036         d_add (dentry, inode);
2037         *dentry_p = dentry;
2038         return inode;
2039 }
2040
2041 static const struct super_operations gadget_fs_operations = {
2042         .statfs =       simple_statfs,
2043         .drop_inode =   generic_delete_inode,
2044 };
2045
2046 static int
2047 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2048 {
2049         struct inode    *inode;
2050         struct dev_data *dev;
2051
2052         if (the_device)
2053                 return -ESRCH;
2054
2055         /* fake probe to determine $CHIP */
2056         usb_gadget_probe_driver(&probe_driver);
2057         if (!CHIP)
2058                 return -ENODEV;
2059
2060         /* superblock */
2061         sb->s_blocksize = PAGE_CACHE_SIZE;
2062         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2063         sb->s_magic = GADGETFS_MAGIC;
2064         sb->s_op = &gadget_fs_operations;
2065         sb->s_time_gran = 1;
2066
2067         /* root inode */
2068         inode = gadgetfs_make_inode (sb,
2069                         NULL, &simple_dir_operations,
2070                         S_IFDIR | S_IRUGO | S_IXUGO);
2071         if (!inode)
2072                 goto Enomem;
2073         inode->i_op = &simple_dir_inode_operations;
2074         if (!(sb->s_root = d_make_root (inode)))
2075                 goto Enomem;
2076
2077         /* the ep0 file is named after the controller we expect;
2078          * user mode code can use it for sanity checks, like we do.
2079          */
2080         dev = dev_new ();
2081         if (!dev)
2082                 goto Enomem;
2083
2084         dev->sb = sb;
2085         if (!gadgetfs_create_file (sb, CHIP,
2086                                 dev, &dev_init_operations,
2087                                 &dev->dentry)) {
2088                 put_dev(dev);
2089                 goto Enomem;
2090         }
2091
2092         /* other endpoint files are available after hardware setup,
2093          * from binding to a controller.
2094          */
2095         the_device = dev;
2096         return 0;
2097
2098 Enomem:
2099         return -ENOMEM;
2100 }
2101
2102 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2103 static struct dentry *
2104 gadgetfs_mount (struct file_system_type *t, int flags,
2105                 const char *path, void *opts)
2106 {
2107         return mount_single (t, flags, opts, gadgetfs_fill_super);
2108 }
2109
2110 static void
2111 gadgetfs_kill_sb (struct super_block *sb)
2112 {
2113         kill_litter_super (sb);
2114         if (the_device) {
2115                 put_dev (the_device);
2116                 the_device = NULL;
2117         }
2118 }
2119
2120 /*----------------------------------------------------------------------*/
2121
2122 static struct file_system_type gadgetfs_type = {
2123         .owner          = THIS_MODULE,
2124         .name           = shortname,
2125         .mount          = gadgetfs_mount,
2126         .kill_sb        = gadgetfs_kill_sb,
2127 };
2128
2129 /*----------------------------------------------------------------------*/
2130
2131 static int __init init (void)
2132 {
2133         int status;
2134
2135         status = register_filesystem (&gadgetfs_type);
2136         if (status == 0)
2137                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2138                         shortname, driver_desc);
2139         return status;
2140 }
2141 module_init (init);
2142
2143 static void __exit cleanup (void)
2144 {
2145         pr_debug ("unregister %s\n", shortname);
2146         unregister_filesystem (&gadgetfs_type);
2147 }
2148 module_exit (cleanup);
2149