USB: gadgetfs simplifications
[linux-2.6.git] / drivers / usb / gadget / inode.c
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  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
20  */
21
22
23 // #define      DEBUG                   /* data to help fault diagnosis */
24 // #define      VERBOSE         /* extra debug messages (success too) */
25
26 #include <linux/init.h>
27 #include <linux/module.h>
28 #include <linux/fs.h>
29 #include <linux/pagemap.h>
30 #include <linux/uts.h>
31 #include <linux/wait.h>
32 #include <linux/compiler.h>
33 #include <asm/uaccess.h>
34 #include <linux/slab.h>
35 #include <linux/poll.h>
36
37 #include <linux/device.h>
38 #include <linux/moduleparam.h>
39
40 #include <linux/usb_gadgetfs.h>
41 #include <linux/usb_gadget.h>
42
43
44 /*
45  * The gadgetfs API maps each endpoint to a file descriptor so that you
46  * can use standard synchronous read/write calls for I/O.  There's some
47  * O_NONBLOCK and O_ASYNC/FASYNC style i/o support.  Example usermode
48  * drivers show how this works in practice.  You can also use AIO to
49  * eliminate I/O gaps between requests, to help when streaming data.
50  *
51  * Key parts that must be USB-specific are protocols defining how the
52  * read/write operations relate to the hardware state machines.  There
53  * are two types of files.  One type is for the device, implementing ep0.
54  * The other type is for each IN or OUT endpoint.  In both cases, the
55  * user mode driver must configure the hardware before using it.
56  *
57  * - First, dev_config() is called when /dev/gadget/$CHIP is configured
58  *   (by writing configuration and device descriptors).  Afterwards it
59  *   may serve as a source of device events, used to handle all control
60  *   requests other than basic enumeration.
61  *
62  * - Then, after a SET_CONFIGURATION control request, ep_config() is
63  *   called when each /dev/gadget/ep* file is configured (by writing
64  *   endpoint descriptors).  Afterwards these files are used to write()
65  *   IN data or to read() OUT data.  To halt the endpoint, a "wrong
66  *   direction" request is issued (like reading an IN endpoint).
67  *
68  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
69  * not possible on all hardware.  For example, precise fault handling with
70  * respect to data left in endpoint fifos after aborted operations; or
71  * selective clearing of endpoint halts, to implement SET_INTERFACE.
72  */
73
74 #define DRIVER_DESC     "USB Gadget filesystem"
75 #define DRIVER_VERSION  "24 Aug 2004"
76
77 static const char driver_desc [] = DRIVER_DESC;
78 static const char shortname [] = "gadgetfs";
79
80 MODULE_DESCRIPTION (DRIVER_DESC);
81 MODULE_AUTHOR ("David Brownell");
82 MODULE_LICENSE ("GPL");
83
84
85 /*----------------------------------------------------------------------*/
86
87 #define GADGETFS_MAGIC          0xaee71ee7
88 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
89
90 /* /dev/gadget/$CHIP represents ep0 and the whole device */
91 enum ep0_state {
92         /* DISBLED is the initial state.
93          */
94         STATE_DEV_DISABLED = 0,
95
96         /* Only one open() of /dev/gadget/$CHIP; only one file tracks
97          * ep0/device i/o modes and binding to the controller.  Driver
98          * must always write descriptors to initialize the device, then
99          * the device becomes UNCONNECTED until enumeration.
100          */
101         STATE_DEV_OPENED,
102
103         /* From then on, ep0 fd is in either of two basic modes:
104          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
105          * - SETUP: read/write will transfer control data and succeed;
106          *   or if "wrong direction", performs protocol stall
107          */
108         STATE_DEV_UNCONNECTED,
109         STATE_DEV_CONNECTED,
110         STATE_DEV_SETUP,
111
112         /* UNBOUND means the driver closed ep0, so the device won't be
113          * accessible again (DEV_DISABLED) until all fds are closed.
114          */
115         STATE_DEV_UNBOUND,
116 };
117
118 /* enough for the whole queue: most events invalidate others */
119 #define N_EVENT                 5
120
121 struct dev_data {
122         spinlock_t                      lock;
123         atomic_t                        count;
124         enum ep0_state                  state;          /* P: lock */
125         struct usb_gadgetfs_event       event [N_EVENT];
126         unsigned                        ev_next;
127         struct fasync_struct            *fasync;
128         u8                              current_config;
129
130         /* drivers reading ep0 MUST handle control requests (SETUP)
131          * reported that way; else the host will time out.
132          */
133         unsigned                        usermode_setup : 1,
134                                         setup_in : 1,
135                                         setup_can_stall : 1,
136                                         setup_out_ready : 1,
137                                         setup_out_error : 1,
138                                         setup_abort : 1;
139         unsigned                        setup_wLength;
140
141         /* the rest is basically write-once */
142         struct usb_config_descriptor    *config, *hs_config;
143         struct usb_device_descriptor    *dev;
144         struct usb_request              *req;
145         struct usb_gadget               *gadget;
146         struct list_head                epfiles;
147         void                            *buf;
148         wait_queue_head_t               wait;
149         struct super_block              *sb;
150         struct dentry                   *dentry;
151
152         /* except this scratch i/o buffer for ep0 */
153         u8                              rbuf [256];
154 };
155
156 static inline void get_dev (struct dev_data *data)
157 {
158         atomic_inc (&data->count);
159 }
160
161 static void put_dev (struct dev_data *data)
162 {
163         if (likely (!atomic_dec_and_test (&data->count)))
164                 return;
165         /* needs no more cleanup */
166         BUG_ON (waitqueue_active (&data->wait));
167         kfree (data);
168 }
169
170 static struct dev_data *dev_new (void)
171 {
172         struct dev_data         *dev;
173
174         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
175         if (!dev)
176                 return NULL;
177         dev->state = STATE_DEV_DISABLED;
178         atomic_set (&dev->count, 1);
179         spin_lock_init (&dev->lock);
180         INIT_LIST_HEAD (&dev->epfiles);
181         init_waitqueue_head (&dev->wait);
182         return dev;
183 }
184
185 /*----------------------------------------------------------------------*/
186
187 /* other /dev/gadget/$ENDPOINT files represent endpoints */
188 enum ep_state {
189         STATE_EP_DISABLED = 0,
190         STATE_EP_READY,
191         STATE_EP_ENABLED,
192         STATE_EP_UNBOUND,
193 };
194
195 struct ep_data {
196         struct semaphore                lock;
197         enum ep_state                   state;
198         atomic_t                        count;
199         struct dev_data                 *dev;
200         /* must hold dev->lock before accessing ep or req */
201         struct usb_ep                   *ep;
202         struct usb_request              *req;
203         ssize_t                         status;
204         char                            name [16];
205         struct usb_endpoint_descriptor  desc, hs_desc;
206         struct list_head                epfiles;
207         wait_queue_head_t               wait;
208         struct dentry                   *dentry;
209         struct inode                    *inode;
210 };
211
212 static inline void get_ep (struct ep_data *data)
213 {
214         atomic_inc (&data->count);
215 }
216
217 static void put_ep (struct ep_data *data)
218 {
219         if (likely (!atomic_dec_and_test (&data->count)))
220                 return;
221         put_dev (data->dev);
222         /* needs no more cleanup */
223         BUG_ON (!list_empty (&data->epfiles));
224         BUG_ON (waitqueue_active (&data->wait));
225         kfree (data);
226 }
227
228 /*----------------------------------------------------------------------*/
229
230 /* most "how to use the hardware" policy choices are in userspace:
231  * mapping endpoint roles (which the driver needs) to the capabilities
232  * which the usb controller has.  most of those capabilities are exposed
233  * implicitly, starting with the driver name and then endpoint names.
234  */
235
236 static const char *CHIP;
237
238 /*----------------------------------------------------------------------*/
239
240 /* NOTE:  don't use dev_printk calls before binding to the gadget
241  * at the end of ep0 configuration, or after unbind.
242  */
243
244 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
245 #define xprintk(d,level,fmt,args...) \
246         printk(level "%s: " fmt , shortname , ## args)
247
248 #ifdef DEBUG
249 #define DBG(dev,fmt,args...) \
250         xprintk(dev , KERN_DEBUG , fmt , ## args)
251 #else
252 #define DBG(dev,fmt,args...) \
253         do { } while (0)
254 #endif /* DEBUG */
255
256 #ifdef VERBOSE
257 #define VDEBUG  DBG
258 #else
259 #define VDEBUG(dev,fmt,args...) \
260         do { } while (0)
261 #endif /* DEBUG */
262
263 #define ERROR(dev,fmt,args...) \
264         xprintk(dev , KERN_ERR , fmt , ## args)
265 #define WARN(dev,fmt,args...) \
266         xprintk(dev , KERN_WARNING , fmt , ## args)
267 #define INFO(dev,fmt,args...) \
268         xprintk(dev , KERN_INFO , fmt , ## args)
269
270
271 /*----------------------------------------------------------------------*/
272
273 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
274  *
275  * After opening, configure non-control endpoints.  Then use normal
276  * stream read() and write() requests; and maybe ioctl() to get more
277  * precise FIFO status when recovering from cancellation.
278  */
279
280 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
281 {
282         struct ep_data  *epdata = ep->driver_data;
283
284         if (!req->context)
285                 return;
286         if (req->status)
287                 epdata->status = req->status;
288         else
289                 epdata->status = req->actual;
290         complete ((struct completion *)req->context);
291 }
292
293 /* tasklock endpoint, returning when it's connected.
294  * still need dev->lock to use epdata->ep.
295  */
296 static int
297 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
298 {
299         int     val;
300
301         if (f_flags & O_NONBLOCK) {
302                 if (down_trylock (&epdata->lock) != 0)
303                         goto nonblock;
304                 if (epdata->state != STATE_EP_ENABLED) {
305                         up (&epdata->lock);
306 nonblock:
307                         val = -EAGAIN;
308                 } else
309                         val = 0;
310                 return val;
311         }
312
313         if ((val = down_interruptible (&epdata->lock)) < 0)
314                 return val;
315
316         switch (epdata->state) {
317         case STATE_EP_ENABLED:
318                 break;
319         // case STATE_EP_DISABLED:              /* "can't happen" */
320         // case STATE_EP_READY:                 /* "can't happen" */
321         default:                                /* error! */
322                 pr_debug ("%s: ep %p not available, state %d\n",
323                                 shortname, epdata, epdata->state);
324                 // FALLTHROUGH
325         case STATE_EP_UNBOUND:                  /* clean disconnect */
326                 val = -ENODEV;
327                 up (&epdata->lock);
328         }
329         return val;
330 }
331
332 static ssize_t
333 ep_io (struct ep_data *epdata, void *buf, unsigned len)
334 {
335         DECLARE_COMPLETION_ONSTACK (done);
336         int value;
337
338         spin_lock_irq (&epdata->dev->lock);
339         if (likely (epdata->ep != NULL)) {
340                 struct usb_request      *req = epdata->req;
341
342                 req->context = &done;
343                 req->complete = epio_complete;
344                 req->buf = buf;
345                 req->length = len;
346                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
347         } else
348                 value = -ENODEV;
349         spin_unlock_irq (&epdata->dev->lock);
350
351         if (likely (value == 0)) {
352                 value = wait_event_interruptible (done.wait, done.done);
353                 if (value != 0) {
354                         spin_lock_irq (&epdata->dev->lock);
355                         if (likely (epdata->ep != NULL)) {
356                                 DBG (epdata->dev, "%s i/o interrupted\n",
357                                                 epdata->name);
358                                 usb_ep_dequeue (epdata->ep, epdata->req);
359                                 spin_unlock_irq (&epdata->dev->lock);
360
361                                 wait_event (done.wait, done.done);
362                                 if (epdata->status == -ECONNRESET)
363                                         epdata->status = -EINTR;
364                         } else {
365                                 spin_unlock_irq (&epdata->dev->lock);
366
367                                 DBG (epdata->dev, "endpoint gone\n");
368                                 epdata->status = -ENODEV;
369                         }
370                 }
371                 return epdata->status;
372         }
373         return value;
374 }
375
376
377 /* handle a synchronous OUT bulk/intr/iso transfer */
378 static ssize_t
379 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
380 {
381         struct ep_data          *data = fd->private_data;
382         void                    *kbuf;
383         ssize_t                 value;
384
385         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
386                 return value;
387
388         /* halt any endpoint by doing a "wrong direction" i/o call */
389         if (data->desc.bEndpointAddress & USB_DIR_IN) {
390                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
391                                 == USB_ENDPOINT_XFER_ISOC)
392                         return -EINVAL;
393                 DBG (data->dev, "%s halt\n", data->name);
394                 spin_lock_irq (&data->dev->lock);
395                 if (likely (data->ep != NULL))
396                         usb_ep_set_halt (data->ep);
397                 spin_unlock_irq (&data->dev->lock);
398                 up (&data->lock);
399                 return -EBADMSG;
400         }
401
402         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
403
404         value = -ENOMEM;
405         kbuf = kmalloc (len, GFP_KERNEL);
406         if (unlikely (!kbuf))
407                 goto free1;
408
409         value = ep_io (data, kbuf, len);
410         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
411                 data->name, len, (int) value);
412         if (value >= 0 && copy_to_user (buf, kbuf, value))
413                 value = -EFAULT;
414
415 free1:
416         up (&data->lock);
417         kfree (kbuf);
418         return value;
419 }
420
421 /* handle a synchronous IN bulk/intr/iso transfer */
422 static ssize_t
423 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
424 {
425         struct ep_data          *data = fd->private_data;
426         void                    *kbuf;
427         ssize_t                 value;
428
429         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
430                 return value;
431
432         /* halt any endpoint by doing a "wrong direction" i/o call */
433         if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
434                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
435                                 == USB_ENDPOINT_XFER_ISOC)
436                         return -EINVAL;
437                 DBG (data->dev, "%s halt\n", data->name);
438                 spin_lock_irq (&data->dev->lock);
439                 if (likely (data->ep != NULL))
440                         usb_ep_set_halt (data->ep);
441                 spin_unlock_irq (&data->dev->lock);
442                 up (&data->lock);
443                 return -EBADMSG;
444         }
445
446         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
447
448         value = -ENOMEM;
449         kbuf = kmalloc (len, GFP_KERNEL);
450         if (!kbuf)
451                 goto free1;
452         if (copy_from_user (kbuf, buf, len)) {
453                 value = -EFAULT;
454                 goto free1;
455         }
456
457         value = ep_io (data, kbuf, len);
458         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
459                 data->name, len, (int) value);
460 free1:
461         up (&data->lock);
462         kfree (kbuf);
463         return value;
464 }
465
466 static int
467 ep_release (struct inode *inode, struct file *fd)
468 {
469         struct ep_data          *data = fd->private_data;
470         int value;
471
472         if ((value = down_interruptible(&data->lock)) < 0)
473                 return value;
474
475         /* clean up if this can be reopened */
476         if (data->state != STATE_EP_UNBOUND) {
477                 data->state = STATE_EP_DISABLED;
478                 data->desc.bDescriptorType = 0;
479                 data->hs_desc.bDescriptorType = 0;
480                 usb_ep_disable(data->ep);
481         }
482         up (&data->lock);
483         put_ep (data);
484         return 0;
485 }
486
487 static int ep_ioctl (struct inode *inode, struct file *fd,
488                 unsigned code, unsigned long value)
489 {
490         struct ep_data          *data = fd->private_data;
491         int                     status;
492
493         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
494                 return status;
495
496         spin_lock_irq (&data->dev->lock);
497         if (likely (data->ep != NULL)) {
498                 switch (code) {
499                 case GADGETFS_FIFO_STATUS:
500                         status = usb_ep_fifo_status (data->ep);
501                         break;
502                 case GADGETFS_FIFO_FLUSH:
503                         usb_ep_fifo_flush (data->ep);
504                         break;
505                 case GADGETFS_CLEAR_HALT:
506                         status = usb_ep_clear_halt (data->ep);
507                         break;
508                 default:
509                         status = -ENOTTY;
510                 }
511         } else
512                 status = -ENODEV;
513         spin_unlock_irq (&data->dev->lock);
514         up (&data->lock);
515         return status;
516 }
517
518 /*----------------------------------------------------------------------*/
519
520 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
521
522 struct kiocb_priv {
523         struct usb_request      *req;
524         struct ep_data          *epdata;
525         void                    *buf;
526         const struct iovec      *iv;
527         unsigned long           nr_segs;
528         unsigned                actual;
529 };
530
531 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
532 {
533         struct kiocb_priv       *priv = iocb->private;
534         struct ep_data          *epdata;
535         int                     value;
536
537         local_irq_disable();
538         epdata = priv->epdata;
539         // spin_lock(&epdata->dev->lock);
540         kiocbSetCancelled(iocb);
541         if (likely(epdata && epdata->ep && priv->req))
542                 value = usb_ep_dequeue (epdata->ep, priv->req);
543         else
544                 value = -EINVAL;
545         // spin_unlock(&epdata->dev->lock);
546         local_irq_enable();
547
548         aio_put_req(iocb);
549         return value;
550 }
551
552 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
553 {
554         struct kiocb_priv       *priv = iocb->private;
555         ssize_t                 len, total;
556         int                     i;
557
558         /* we "retry" to get the right mm context for this: */
559
560         /* copy stuff into user buffers */
561         total = priv->actual;
562         len = 0;
563         for (i=0; i < priv->nr_segs; i++) {
564                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
565
566                 if (copy_to_user(priv->iv[i].iov_base, priv->buf, this)) {
567                         if (len == 0)
568                                 len = -EFAULT;
569                         break;
570                 }
571
572                 total -= this;
573                 len += this;
574                 if (total == 0)
575                         break;
576         }
577         kfree(priv->buf);
578         kfree(priv);
579         aio_put_req(iocb);
580         return len;
581 }
582
583 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
584 {
585         struct kiocb            *iocb = req->context;
586         struct kiocb_priv       *priv = iocb->private;
587         struct ep_data          *epdata = priv->epdata;
588
589         /* lock against disconnect (and ideally, cancel) */
590         spin_lock(&epdata->dev->lock);
591         priv->req = NULL;
592         priv->epdata = NULL;
593         if (priv->iv == NULL
594                         || unlikely(req->actual == 0)
595                         || unlikely(kiocbIsCancelled(iocb))) {
596                 kfree(req->buf);
597                 kfree(priv);
598                 iocb->private = NULL;
599                 /* aio_complete() reports bytes-transferred _and_ faults */
600                 if (unlikely(kiocbIsCancelled(iocb)))
601                         aio_put_req(iocb);
602                 else
603                         aio_complete(iocb,
604                                 req->actual ? req->actual : req->status,
605                                 req->status);
606         } else {
607                 /* retry() won't report both; so we hide some faults */
608                 if (unlikely(0 != req->status))
609                         DBG(epdata->dev, "%s fault %d len %d\n",
610                                 ep->name, req->status, req->actual);
611
612                 priv->buf = req->buf;
613                 priv->actual = req->actual;
614                 kick_iocb(iocb);
615         }
616         spin_unlock(&epdata->dev->lock);
617
618         usb_ep_free_request(ep, req);
619         put_ep(epdata);
620 }
621
622 static ssize_t
623 ep_aio_rwtail(
624         struct kiocb    *iocb,
625         char            *buf,
626         size_t          len,
627         struct ep_data  *epdata,
628         const struct iovec *iv,
629         unsigned long   nr_segs
630 )
631 {
632         struct kiocb_priv       *priv;
633         struct usb_request      *req;
634         ssize_t                 value;
635
636         priv = kmalloc(sizeof *priv, GFP_KERNEL);
637         if (!priv) {
638                 value = -ENOMEM;
639 fail:
640                 kfree(buf);
641                 return value;
642         }
643         iocb->private = priv;
644         priv->iv = iv;
645         priv->nr_segs = nr_segs;
646
647         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
648         if (unlikely(value < 0)) {
649                 kfree(priv);
650                 goto fail;
651         }
652
653         iocb->ki_cancel = ep_aio_cancel;
654         get_ep(epdata);
655         priv->epdata = epdata;
656         priv->actual = 0;
657
658         /* each kiocb is coupled to one usb_request, but we can't
659          * allocate or submit those if the host disconnected.
660          */
661         spin_lock_irq(&epdata->dev->lock);
662         if (likely(epdata->ep)) {
663                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
664                 if (likely(req)) {
665                         priv->req = req;
666                         req->buf = buf;
667                         req->length = len;
668                         req->complete = ep_aio_complete;
669                         req->context = iocb;
670                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
671                         if (unlikely(0 != value))
672                                 usb_ep_free_request(epdata->ep, req);
673                 } else
674                         value = -EAGAIN;
675         } else
676                 value = -ENODEV;
677         spin_unlock_irq(&epdata->dev->lock);
678
679         up(&epdata->lock);
680
681         if (unlikely(value)) {
682                 kfree(priv);
683                 put_ep(epdata);
684         } else
685                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
686         return value;
687 }
688
689 static ssize_t
690 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
691                 unsigned long nr_segs, loff_t o)
692 {
693         struct ep_data          *epdata = iocb->ki_filp->private_data;
694         char                    *buf;
695
696         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
697                 return -EINVAL;
698
699         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
700         if (unlikely(!buf))
701                 return -ENOMEM;
702
703         iocb->ki_retry = ep_aio_read_retry;
704         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
705 }
706
707 static ssize_t
708 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
709                 unsigned long nr_segs, loff_t o)
710 {
711         struct ep_data          *epdata = iocb->ki_filp->private_data;
712         char                    *buf;
713         size_t                  len = 0;
714         int                     i = 0;
715
716         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
717                 return -EINVAL;
718
719         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
720         if (unlikely(!buf))
721                 return -ENOMEM;
722
723         for (i=0; i < nr_segs; i++) {
724                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
725                                 iov[i].iov_len) != 0)) {
726                         kfree(buf);
727                         return -EFAULT;
728                 }
729                 len += iov[i].iov_len;
730         }
731         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
732 }
733
734 /*----------------------------------------------------------------------*/
735
736 /* used after endpoint configuration */
737 static const struct file_operations ep_io_operations = {
738         .owner =        THIS_MODULE,
739         .llseek =       no_llseek,
740
741         .read =         ep_read,
742         .write =        ep_write,
743         .ioctl =        ep_ioctl,
744         .release =      ep_release,
745
746         .aio_read =     ep_aio_read,
747         .aio_write =    ep_aio_write,
748 };
749
750 /* ENDPOINT INITIALIZATION
751  *
752  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
753  *     status = write (fd, descriptors, sizeof descriptors)
754  *
755  * That write establishes the endpoint configuration, configuring
756  * the controller to process bulk, interrupt, or isochronous transfers
757  * at the right maxpacket size, and so on.
758  *
759  * The descriptors are message type 1, identified by a host order u32
760  * at the beginning of what's written.  Descriptor order is: full/low
761  * speed descriptor, then optional high speed descriptor.
762  */
763 static ssize_t
764 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
765 {
766         struct ep_data          *data = fd->private_data;
767         struct usb_ep           *ep;
768         u32                     tag;
769         int                     value, length = len;
770
771         if ((value = down_interruptible (&data->lock)) < 0)
772                 return value;
773
774         if (data->state != STATE_EP_READY) {
775                 value = -EL2HLT;
776                 goto fail;
777         }
778
779         value = len;
780         if (len < USB_DT_ENDPOINT_SIZE + 4)
781                 goto fail0;
782
783         /* we might need to change message format someday */
784         if (copy_from_user (&tag, buf, 4)) {
785                 goto fail1;
786         }
787         if (tag != 1) {
788                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
789                 goto fail0;
790         }
791         buf += 4;
792         len -= 4;
793
794         /* NOTE:  audio endpoint extensions not accepted here;
795          * just don't include the extra bytes.
796          */
797
798         /* full/low speed descriptor, then high speed */
799         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
800                 goto fail1;
801         }
802         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
803                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
804                 goto fail0;
805         if (len != USB_DT_ENDPOINT_SIZE) {
806                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
807                         goto fail0;
808                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
809                                         USB_DT_ENDPOINT_SIZE)) {
810                         goto fail1;
811                 }
812                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
813                                 || data->hs_desc.bDescriptorType
814                                         != USB_DT_ENDPOINT) {
815                         DBG(data->dev, "config %s, bad hs length or type\n",
816                                         data->name);
817                         goto fail0;
818                 }
819         }
820
821         spin_lock_irq (&data->dev->lock);
822         if (data->dev->state == STATE_DEV_UNBOUND) {
823                 value = -ENOENT;
824                 goto gone;
825         } else if ((ep = data->ep) == NULL) {
826                 value = -ENODEV;
827                 goto gone;
828         }
829         switch (data->dev->gadget->speed) {
830         case USB_SPEED_LOW:
831         case USB_SPEED_FULL:
832                 value = usb_ep_enable (ep, &data->desc);
833                 if (value == 0)
834                         data->state = STATE_EP_ENABLED;
835                 break;
836 #ifdef  CONFIG_USB_GADGET_DUALSPEED
837         case USB_SPEED_HIGH:
838                 /* fails if caller didn't provide that descriptor... */
839                 value = usb_ep_enable (ep, &data->hs_desc);
840                 if (value == 0)
841                         data->state = STATE_EP_ENABLED;
842                 break;
843 #endif
844         default:
845                 DBG(data->dev, "unconnected, %s init abandoned\n",
846                                 data->name);
847                 value = -EINVAL;
848         }
849         if (value == 0) {
850                 fd->f_op = &ep_io_operations;
851                 value = length;
852         }
853 gone:
854         spin_unlock_irq (&data->dev->lock);
855         if (value < 0) {
856 fail:
857                 data->desc.bDescriptorType = 0;
858                 data->hs_desc.bDescriptorType = 0;
859         }
860         up (&data->lock);
861         return value;
862 fail0:
863         value = -EINVAL;
864         goto fail;
865 fail1:
866         value = -EFAULT;
867         goto fail;
868 }
869
870 static int
871 ep_open (struct inode *inode, struct file *fd)
872 {
873         struct ep_data          *data = inode->i_private;
874         int                     value = -EBUSY;
875
876         if (down_interruptible (&data->lock) != 0)
877                 return -EINTR;
878         spin_lock_irq (&data->dev->lock);
879         if (data->dev->state == STATE_DEV_UNBOUND)
880                 value = -ENOENT;
881         else if (data->state == STATE_EP_DISABLED) {
882                 value = 0;
883                 data->state = STATE_EP_READY;
884                 get_ep (data);
885                 fd->private_data = data;
886                 VDEBUG (data->dev, "%s ready\n", data->name);
887         } else
888                 DBG (data->dev, "%s state %d\n",
889                         data->name, data->state);
890         spin_unlock_irq (&data->dev->lock);
891         up (&data->lock);
892         return value;
893 }
894
895 /* used before endpoint configuration */
896 static const struct file_operations ep_config_operations = {
897         .owner =        THIS_MODULE,
898         .llseek =       no_llseek,
899
900         .open =         ep_open,
901         .write =        ep_config,
902         .release =      ep_release,
903 };
904
905 /*----------------------------------------------------------------------*/
906
907 /* EP0 IMPLEMENTATION can be partly in userspace.
908  *
909  * Drivers that use this facility receive various events, including
910  * control requests the kernel doesn't handle.  Drivers that don't
911  * use this facility may be too simple-minded for real applications.
912  */
913
914 static inline void ep0_readable (struct dev_data *dev)
915 {
916         wake_up (&dev->wait);
917         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
918 }
919
920 static void clean_req (struct usb_ep *ep, struct usb_request *req)
921 {
922         struct dev_data         *dev = ep->driver_data;
923
924         if (req->buf != dev->rbuf) {
925                 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
926                 req->buf = dev->rbuf;
927                 req->dma = DMA_ADDR_INVALID;
928         }
929         req->complete = epio_complete;
930         dev->setup_out_ready = 0;
931 }
932
933 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
934 {
935         struct dev_data         *dev = ep->driver_data;
936         int                     free = 1;
937
938         /* for control OUT, data must still get to userspace */
939         if (!dev->setup_in) {
940                 dev->setup_out_error = (req->status != 0);
941                 if (!dev->setup_out_error)
942                         free = 0;
943                 dev->setup_out_ready = 1;
944                 ep0_readable (dev);
945         } else {
946                 unsigned long   flags;
947
948                 spin_lock_irqsave(&dev->lock, flags);
949                 if (dev->state == STATE_DEV_SETUP)
950                         dev->state = STATE_DEV_CONNECTED;
951                 spin_unlock_irqrestore(&dev->lock, flags);
952         }
953
954         /* clean up as appropriate */
955         if (free && req->buf != &dev->rbuf)
956                 clean_req (ep, req);
957         req->complete = epio_complete;
958 }
959
960 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
961 {
962         struct dev_data *dev = ep->driver_data;
963
964         if (dev->setup_out_ready) {
965                 DBG (dev, "ep0 request busy!\n");
966                 return -EBUSY;
967         }
968         if (len > sizeof (dev->rbuf))
969                 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
970         if (req->buf == 0) {
971                 req->buf = dev->rbuf;
972                 return -ENOMEM;
973         }
974         req->complete = ep0_complete;
975         req->length = len;
976         req->zero = 0;
977         return 0;
978 }
979
980 static ssize_t
981 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
982 {
983         struct dev_data                 *dev = fd->private_data;
984         ssize_t                         retval;
985         enum ep0_state                  state;
986
987         spin_lock_irq (&dev->lock);
988
989         /* report fd mode change before acting on it */
990         if (dev->setup_abort) {
991                 dev->setup_abort = 0;
992                 retval = -EIDRM;
993                 goto done;
994         }
995
996         /* control DATA stage */
997         if ((state = dev->state) == STATE_DEV_SETUP) {
998
999                 if (dev->setup_in) {            /* stall IN */
1000                         VDEBUG(dev, "ep0in stall\n");
1001                         (void) usb_ep_set_halt (dev->gadget->ep0);
1002                         retval = -EL2HLT;
1003                         dev->state = STATE_DEV_CONNECTED;
1004
1005                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1006                         struct usb_ep           *ep = dev->gadget->ep0;
1007                         struct usb_request      *req = dev->req;
1008
1009                         if ((retval = setup_req (ep, req, 0)) == 0)
1010                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1011                         dev->state = STATE_DEV_CONNECTED;
1012
1013                         /* assume that was SET_CONFIGURATION */
1014                         if (dev->current_config) {
1015                                 unsigned power;
1016 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1017                                 if (dev->gadget->speed == USB_SPEED_HIGH)
1018                                         power = dev->hs_config->bMaxPower;
1019                                 else
1020 #endif
1021                                         power = dev->config->bMaxPower;
1022                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1023                         }
1024
1025                 } else {                        /* collect OUT data */
1026                         if ((fd->f_flags & O_NONBLOCK) != 0
1027                                         && !dev->setup_out_ready) {
1028                                 retval = -EAGAIN;
1029                                 goto done;
1030                         }
1031                         spin_unlock_irq (&dev->lock);
1032                         retval = wait_event_interruptible (dev->wait,
1033                                         dev->setup_out_ready != 0);
1034
1035                         /* FIXME state could change from under us */
1036                         spin_lock_irq (&dev->lock);
1037                         if (retval)
1038                                 goto done;
1039                         if (dev->setup_out_error)
1040                                 retval = -EIO;
1041                         else {
1042                                 len = min (len, (size_t)dev->req->actual);
1043 // FIXME don't call this with the spinlock held ...
1044                                 if (copy_to_user (buf, dev->req->buf, len))
1045                                         retval = -EFAULT;
1046                                 clean_req (dev->gadget->ep0, dev->req);
1047                                 /* NOTE userspace can't yet choose to stall */
1048                         }
1049                 }
1050                 goto done;
1051         }
1052
1053         /* else normal: return event data */
1054         if (len < sizeof dev->event [0]) {
1055                 retval = -EINVAL;
1056                 goto done;
1057         }
1058         len -= len % sizeof (struct usb_gadgetfs_event);
1059         dev->usermode_setup = 1;
1060
1061 scan:
1062         /* return queued events right away */
1063         if (dev->ev_next != 0) {
1064                 unsigned                i, n;
1065
1066                 n = len / sizeof (struct usb_gadgetfs_event);
1067                 if (dev->ev_next < n)
1068                         n = dev->ev_next;
1069
1070                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1071                 for (i = 0; i < n; i++) {
1072                         if (dev->event [i].type == GADGETFS_SETUP) {
1073                                 dev->state = STATE_DEV_SETUP;
1074                                 n = i + 1;
1075                                 break;
1076                         }
1077                 }
1078                 spin_unlock_irq (&dev->lock);
1079                 len = n * sizeof (struct usb_gadgetfs_event);
1080                 if (copy_to_user (buf, &dev->event, len))
1081                         retval = -EFAULT;
1082                 else
1083                         retval = len;
1084                 if (len > 0) {
1085                         /* NOTE this doesn't guard against broken drivers;
1086                          * concurrent ep0 readers may lose events.
1087                          */
1088                         spin_lock_irq (&dev->lock);
1089                         if (dev->ev_next > n) {
1090                                 memmove(&dev->event[0], &dev->event[n],
1091                                         sizeof (struct usb_gadgetfs_event)
1092                                                 * (dev->ev_next - n));
1093                         }
1094                         dev->ev_next -= n;
1095                         spin_unlock_irq (&dev->lock);
1096                 }
1097                 return retval;
1098         }
1099         if (fd->f_flags & O_NONBLOCK) {
1100                 retval = -EAGAIN;
1101                 goto done;
1102         }
1103
1104         switch (state) {
1105         default:
1106                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1107                 retval = -ESRCH;
1108                 break;
1109         case STATE_DEV_UNCONNECTED:
1110         case STATE_DEV_CONNECTED:
1111                 spin_unlock_irq (&dev->lock);
1112                 DBG (dev, "%s wait\n", __FUNCTION__);
1113
1114                 /* wait for events */
1115                 retval = wait_event_interruptible (dev->wait,
1116                                 dev->ev_next != 0);
1117                 if (retval < 0)
1118                         return retval;
1119                 spin_lock_irq (&dev->lock);
1120                 goto scan;
1121         }
1122
1123 done:
1124         spin_unlock_irq (&dev->lock);
1125         return retval;
1126 }
1127
1128 static struct usb_gadgetfs_event *
1129 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1130 {
1131         struct usb_gadgetfs_event       *event;
1132         unsigned                        i;
1133
1134         switch (type) {
1135         /* these events purge the queue */
1136         case GADGETFS_DISCONNECT:
1137                 if (dev->state == STATE_DEV_SETUP)
1138                         dev->setup_abort = 1;
1139                 // FALL THROUGH
1140         case GADGETFS_CONNECT:
1141                 dev->ev_next = 0;
1142                 break;
1143         case GADGETFS_SETUP:            /* previous request timed out */
1144         case GADGETFS_SUSPEND:          /* same effect */
1145                 /* these events can't be repeated */
1146                 for (i = 0; i != dev->ev_next; i++) {
1147                         if (dev->event [i].type != type)
1148                                 continue;
1149                         DBG(dev, "discard old event[%d] %d\n", i, type);
1150                         dev->ev_next--;
1151                         if (i == dev->ev_next)
1152                                 break;
1153                         /* indices start at zero, for simplicity */
1154                         memmove (&dev->event [i], &dev->event [i + 1],
1155                                 sizeof (struct usb_gadgetfs_event)
1156                                         * (dev->ev_next - i));
1157                 }
1158                 break;
1159         default:
1160                 BUG ();
1161         }
1162         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1163         event = &dev->event [dev->ev_next++];
1164         BUG_ON (dev->ev_next > N_EVENT);
1165         memset (event, 0, sizeof *event);
1166         event->type = type;
1167         return event;
1168 }
1169
1170 static ssize_t
1171 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1172 {
1173         struct dev_data         *dev = fd->private_data;
1174         ssize_t                 retval = -ESRCH;
1175
1176         spin_lock_irq (&dev->lock);
1177
1178         /* report fd mode change before acting on it */
1179         if (dev->setup_abort) {
1180                 dev->setup_abort = 0;
1181                 retval = -EIDRM;
1182
1183         /* data and/or status stage for control request */
1184         } else if (dev->state == STATE_DEV_SETUP) {
1185
1186                 /* IN DATA+STATUS caller makes len <= wLength */
1187                 if (dev->setup_in) {
1188                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1189                         if (retval == 0) {
1190                                 spin_unlock_irq (&dev->lock);
1191                                 if (copy_from_user (dev->req->buf, buf, len))
1192                                         retval = -EFAULT;
1193                                 else {
1194                                         if (len < dev->setup_wLength)
1195                                                 dev->req->zero = 1;
1196                                         retval = usb_ep_queue (
1197                                                 dev->gadget->ep0, dev->req,
1198                                                 GFP_KERNEL);
1199                                 }
1200                                 if (retval < 0) {
1201                                         spin_lock_irq (&dev->lock);
1202                                         clean_req (dev->gadget->ep0, dev->req);
1203                                         spin_unlock_irq (&dev->lock);
1204                                 } else
1205                                         retval = len;
1206
1207                                 return retval;
1208                         }
1209
1210                 /* can stall some OUT transfers */
1211                 } else if (dev->setup_can_stall) {
1212                         VDEBUG(dev, "ep0out stall\n");
1213                         (void) usb_ep_set_halt (dev->gadget->ep0);
1214                         retval = -EL2HLT;
1215                         dev->state = STATE_DEV_CONNECTED;
1216                 } else {
1217                         DBG(dev, "bogus ep0out stall!\n");
1218                 }
1219         } else
1220                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1221
1222         spin_unlock_irq (&dev->lock);
1223         return retval;
1224 }
1225
1226 static int
1227 ep0_fasync (int f, struct file *fd, int on)
1228 {
1229         struct dev_data         *dev = fd->private_data;
1230         // caller must F_SETOWN before signal delivery happens
1231         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1232         return fasync_helper (f, fd, on, &dev->fasync);
1233 }
1234
1235 static struct usb_gadget_driver gadgetfs_driver;
1236
1237 static int
1238 dev_release (struct inode *inode, struct file *fd)
1239 {
1240         struct dev_data         *dev = fd->private_data;
1241
1242         /* closing ep0 === shutdown all */
1243
1244         usb_gadget_unregister_driver (&gadgetfs_driver);
1245
1246         /* at this point "good" hardware has disconnected the
1247          * device from USB; the host won't see it any more.
1248          * alternatively, all host requests will time out.
1249          */
1250
1251         fasync_helper (-1, fd, 0, &dev->fasync);
1252         kfree (dev->buf);
1253         dev->buf = NULL;
1254         put_dev (dev);
1255
1256         /* other endpoints were all decoupled from this device */
1257         spin_lock_irq(&dev->lock);
1258         dev->state = STATE_DEV_DISABLED;
1259         spin_unlock_irq(&dev->lock);
1260         return 0;
1261 }
1262
1263 static unsigned int
1264 ep0_poll (struct file *fd, poll_table *wait)
1265 {
1266        struct dev_data         *dev = fd->private_data;
1267        int                     mask = 0;
1268
1269        poll_wait(fd, &dev->wait, wait);
1270
1271        spin_lock_irq (&dev->lock);
1272
1273        /* report fd mode change before acting on it */
1274        if (dev->setup_abort) {
1275                dev->setup_abort = 0;
1276                mask = POLLHUP;
1277                goto out;
1278        }
1279
1280        if (dev->state == STATE_DEV_SETUP) {
1281                if (dev->setup_in || dev->setup_can_stall)
1282                        mask = POLLOUT;
1283        } else {
1284                if (dev->ev_next != 0)
1285                        mask = POLLIN;
1286        }
1287 out:
1288        spin_unlock_irq(&dev->lock);
1289        return mask;
1290 }
1291
1292 static int dev_ioctl (struct inode *inode, struct file *fd,
1293                 unsigned code, unsigned long value)
1294 {
1295         struct dev_data         *dev = fd->private_data;
1296         struct usb_gadget       *gadget = dev->gadget;
1297
1298         if (gadget->ops->ioctl)
1299                 return gadget->ops->ioctl (gadget, code, value);
1300         return -ENOTTY;
1301 }
1302
1303 /* used after device configuration */
1304 static const struct file_operations ep0_io_operations = {
1305         .owner =        THIS_MODULE,
1306         .llseek =       no_llseek,
1307
1308         .read =         ep0_read,
1309         .write =        ep0_write,
1310         .fasync =       ep0_fasync,
1311         .poll =         ep0_poll,
1312         .ioctl =        dev_ioctl,
1313         .release =      dev_release,
1314 };
1315
1316 /*----------------------------------------------------------------------*/
1317
1318 /* The in-kernel gadget driver handles most ep0 issues, in particular
1319  * enumerating the single configuration (as provided from user space).
1320  *
1321  * Unrecognized ep0 requests may be handled in user space.
1322  */
1323
1324 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1325 static void make_qualifier (struct dev_data *dev)
1326 {
1327         struct usb_qualifier_descriptor         qual;
1328         struct usb_device_descriptor            *desc;
1329
1330         qual.bLength = sizeof qual;
1331         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1332         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1333
1334         desc = dev->dev;
1335         qual.bDeviceClass = desc->bDeviceClass;
1336         qual.bDeviceSubClass = desc->bDeviceSubClass;
1337         qual.bDeviceProtocol = desc->bDeviceProtocol;
1338
1339         /* assumes ep0 uses the same value for both speeds ... */
1340         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1341
1342         qual.bNumConfigurations = 1;
1343         qual.bRESERVED = 0;
1344
1345         memcpy (dev->rbuf, &qual, sizeof qual);
1346 }
1347 #endif
1348
1349 static int
1350 config_buf (struct dev_data *dev, u8 type, unsigned index)
1351 {
1352         int             len;
1353 #ifdef CONFIG_USB_GADGET_DUALSPEED
1354         int             hs;
1355 #endif
1356
1357         /* only one configuration */
1358         if (index > 0)
1359                 return -EINVAL;
1360
1361 #ifdef CONFIG_USB_GADGET_DUALSPEED
1362         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1363         if (type == USB_DT_OTHER_SPEED_CONFIG)
1364                 hs = !hs;
1365         if (hs) {
1366                 dev->req->buf = dev->hs_config;
1367                 len = le16_to_cpup (&dev->hs_config->wTotalLength);
1368         } else
1369 #endif
1370         {
1371                 dev->req->buf = dev->config;
1372                 len = le16_to_cpup (&dev->config->wTotalLength);
1373         }
1374         ((u8 *)dev->req->buf) [1] = type;
1375         return len;
1376 }
1377
1378 static int
1379 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1380 {
1381         struct dev_data                 *dev = get_gadget_data (gadget);
1382         struct usb_request              *req = dev->req;
1383         int                             value = -EOPNOTSUPP;
1384         struct usb_gadgetfs_event       *event;
1385         u16                             w_value = le16_to_cpu(ctrl->wValue);
1386         u16                             w_length = le16_to_cpu(ctrl->wLength);
1387
1388         spin_lock (&dev->lock);
1389         dev->setup_abort = 0;
1390         if (dev->state == STATE_DEV_UNCONNECTED) {
1391
1392                 dev->state = STATE_DEV_CONNECTED;
1393                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1394
1395 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1396                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1397                         ERROR (dev, "no high speed config??\n");
1398                         return -EINVAL;
1399                 }
1400 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1401
1402                 INFO (dev, "connected\n");
1403                 event = next_event (dev, GADGETFS_CONNECT);
1404                 event->u.speed = gadget->speed;
1405                 ep0_readable (dev);
1406
1407         /* host may have given up waiting for response.  we can miss control
1408          * requests handled lower down (device/endpoint status and features);
1409          * then ep0_{read,write} will report the wrong status. controller
1410          * driver will have aborted pending i/o.
1411          */
1412         } else if (dev->state == STATE_DEV_SETUP)
1413                 dev->setup_abort = 1;
1414
1415         req->buf = dev->rbuf;
1416         req->dma = DMA_ADDR_INVALID;
1417         req->context = NULL;
1418         value = -EOPNOTSUPP;
1419         switch (ctrl->bRequest) {
1420
1421         case USB_REQ_GET_DESCRIPTOR:
1422                 if (ctrl->bRequestType != USB_DIR_IN)
1423                         goto unrecognized;
1424                 switch (w_value >> 8) {
1425
1426                 case USB_DT_DEVICE:
1427                         value = min (w_length, (u16) sizeof *dev->dev);
1428                         req->buf = dev->dev;
1429                         break;
1430 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1431                 case USB_DT_DEVICE_QUALIFIER:
1432                         if (!dev->hs_config)
1433                                 break;
1434                         value = min (w_length, (u16)
1435                                 sizeof (struct usb_qualifier_descriptor));
1436                         make_qualifier (dev);
1437                         break;
1438                 case USB_DT_OTHER_SPEED_CONFIG:
1439                         // FALLTHROUGH
1440 #endif
1441                 case USB_DT_CONFIG:
1442                         value = config_buf (dev,
1443                                         w_value >> 8,
1444                                         w_value & 0xff);
1445                         if (value >= 0)
1446                                 value = min (w_length, (u16) value);
1447                         break;
1448                 case USB_DT_STRING:
1449                         goto unrecognized;
1450
1451                 default:                // all others are errors
1452                         break;
1453                 }
1454                 break;
1455
1456         /* currently one config, two speeds */
1457         case USB_REQ_SET_CONFIGURATION:
1458                 if (ctrl->bRequestType != 0)
1459                         break;
1460                 if (0 == (u8) w_value) {
1461                         value = 0;
1462                         dev->current_config = 0;
1463                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1464                         // user mode expected to disable endpoints
1465                 } else {
1466                         u8      config, power;
1467 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1468                         if (gadget->speed == USB_SPEED_HIGH) {
1469                                 config = dev->hs_config->bConfigurationValue;
1470                                 power = dev->hs_config->bMaxPower;
1471                         } else
1472 #endif
1473                         {
1474                                 config = dev->config->bConfigurationValue;
1475                                 power = dev->config->bMaxPower;
1476                         }
1477
1478                         if (config == (u8) w_value) {
1479                                 value = 0;
1480                                 dev->current_config = config;
1481                                 usb_gadget_vbus_draw(gadget, 2 * power);
1482                         }
1483                 }
1484
1485                 /* report SET_CONFIGURATION like any other control request,
1486                  * except that usermode may not stall this.  the next
1487                  * request mustn't be allowed start until this finishes:
1488                  * endpoints and threads set up, etc.
1489                  *
1490                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1491                  * has bad/racey automagic that prevents synchronizing here.
1492                  * even kernel mode drivers often miss them.
1493                  */
1494                 if (value == 0) {
1495                         INFO (dev, "configuration #%d\n", dev->current_config);
1496                         if (dev->usermode_setup) {
1497                                 dev->setup_can_stall = 0;
1498                                 goto delegate;
1499                         }
1500                 }
1501                 break;
1502
1503 #ifndef CONFIG_USB_GADGETFS_PXA2XX
1504         /* PXA automagically handles this request too */
1505         case USB_REQ_GET_CONFIGURATION:
1506                 if (ctrl->bRequestType != 0x80)
1507                         break;
1508                 *(u8 *)req->buf = dev->current_config;
1509                 value = min (w_length, (u16) 1);
1510                 break;
1511 #endif
1512
1513         default:
1514 unrecognized:
1515                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1516                         dev->usermode_setup ? "delegate" : "fail",
1517                         ctrl->bRequestType, ctrl->bRequest,
1518                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1519
1520                 /* if there's an ep0 reader, don't stall */
1521                 if (dev->usermode_setup) {
1522                         dev->setup_can_stall = 1;
1523 delegate:
1524                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1525                                                 ? 1 : 0;
1526                         dev->setup_wLength = w_length;
1527                         dev->setup_out_ready = 0;
1528                         dev->setup_out_error = 0;
1529                         value = 0;
1530
1531                         /* read DATA stage for OUT right away */
1532                         if (unlikely (!dev->setup_in && w_length)) {
1533                                 value = setup_req (gadget->ep0, dev->req,
1534                                                         w_length);
1535                                 if (value < 0)
1536                                         break;
1537                                 value = usb_ep_queue (gadget->ep0, dev->req,
1538                                                         GFP_ATOMIC);
1539                                 if (value < 0) {
1540                                         clean_req (gadget->ep0, dev->req);
1541                                         break;
1542                                 }
1543
1544                                 /* we can't currently stall these */
1545                                 dev->setup_can_stall = 0;
1546                         }
1547
1548                         /* state changes when reader collects event */
1549                         event = next_event (dev, GADGETFS_SETUP);
1550                         event->u.setup = *ctrl;
1551                         ep0_readable (dev);
1552                         spin_unlock (&dev->lock);
1553                         return 0;
1554                 }
1555         }
1556
1557         /* proceed with data transfer and status phases? */
1558         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1559                 req->length = value;
1560                 req->zero = value < w_length;
1561                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1562                 if (value < 0) {
1563                         DBG (dev, "ep_queue --> %d\n", value);
1564                         req->status = 0;
1565                 }
1566         }
1567
1568         /* device stalls when value < 0 */
1569         spin_unlock (&dev->lock);
1570         return value;
1571 }
1572
1573 static void destroy_ep_files (struct dev_data *dev)
1574 {
1575         struct list_head        *entry, *tmp;
1576
1577         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1578
1579         /* dev->state must prevent interference */
1580 restart:
1581         spin_lock_irq (&dev->lock);
1582         list_for_each_safe (entry, tmp, &dev->epfiles) {
1583                 struct ep_data  *ep;
1584                 struct inode    *parent;
1585                 struct dentry   *dentry;
1586
1587                 /* break link to FS */
1588                 ep = list_entry (entry, struct ep_data, epfiles);
1589                 list_del_init (&ep->epfiles);
1590                 dentry = ep->dentry;
1591                 ep->dentry = NULL;
1592                 parent = dentry->d_parent->d_inode;
1593
1594                 /* break link to controller */
1595                 if (ep->state == STATE_EP_ENABLED)
1596                         (void) usb_ep_disable (ep->ep);
1597                 ep->state = STATE_EP_UNBOUND;
1598                 usb_ep_free_request (ep->ep, ep->req);
1599                 ep->ep = NULL;
1600                 wake_up (&ep->wait);
1601                 put_ep (ep);
1602
1603                 spin_unlock_irq (&dev->lock);
1604
1605                 /* break link to dcache */
1606                 mutex_lock (&parent->i_mutex);
1607                 d_delete (dentry);
1608                 dput (dentry);
1609                 mutex_unlock (&parent->i_mutex);
1610
1611                 /* fds may still be open */
1612                 goto restart;
1613         }
1614         spin_unlock_irq (&dev->lock);
1615 }
1616
1617
1618 static struct inode *
1619 gadgetfs_create_file (struct super_block *sb, char const *name,
1620                 void *data, const struct file_operations *fops,
1621                 struct dentry **dentry_p);
1622
1623 static int activate_ep_files (struct dev_data *dev)
1624 {
1625         struct usb_ep   *ep;
1626         struct ep_data  *data;
1627
1628         gadget_for_each_ep (ep, dev->gadget) {
1629
1630                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1631                 if (!data)
1632                         goto enomem0;
1633                 data->state = STATE_EP_DISABLED;
1634                 init_MUTEX (&data->lock);
1635                 init_waitqueue_head (&data->wait);
1636
1637                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1638                 atomic_set (&data->count, 1);
1639                 data->dev = dev;
1640                 get_dev (dev);
1641
1642                 data->ep = ep;
1643                 ep->driver_data = data;
1644
1645                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1646                 if (!data->req)
1647                         goto enomem1;
1648
1649                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1650                                 data, &ep_config_operations,
1651                                 &data->dentry);
1652                 if (!data->inode)
1653                         goto enomem2;
1654                 list_add_tail (&data->epfiles, &dev->epfiles);
1655         }
1656         return 0;
1657
1658 enomem2:
1659         usb_ep_free_request (ep, data->req);
1660 enomem1:
1661         put_dev (dev);
1662         kfree (data);
1663 enomem0:
1664         DBG (dev, "%s enomem\n", __FUNCTION__);
1665         destroy_ep_files (dev);
1666         return -ENOMEM;
1667 }
1668
1669 static void
1670 gadgetfs_unbind (struct usb_gadget *gadget)
1671 {
1672         struct dev_data         *dev = get_gadget_data (gadget);
1673
1674         DBG (dev, "%s\n", __FUNCTION__);
1675
1676         spin_lock_irq (&dev->lock);
1677         dev->state = STATE_DEV_UNBOUND;
1678         spin_unlock_irq (&dev->lock);
1679
1680         destroy_ep_files (dev);
1681         gadget->ep0->driver_data = NULL;
1682         set_gadget_data (gadget, NULL);
1683
1684         /* we've already been disconnected ... no i/o is active */
1685         if (dev->req)
1686                 usb_ep_free_request (gadget->ep0, dev->req);
1687         DBG (dev, "%s done\n", __FUNCTION__);
1688         put_dev (dev);
1689 }
1690
1691 static struct dev_data          *the_device;
1692
1693 static int
1694 gadgetfs_bind (struct usb_gadget *gadget)
1695 {
1696         struct dev_data         *dev = the_device;
1697
1698         if (!dev)
1699                 return -ESRCH;
1700         if (0 != strcmp (CHIP, gadget->name)) {
1701                 printk (KERN_ERR "%s expected %s controller not %s\n",
1702                         shortname, CHIP, gadget->name);
1703                 return -ENODEV;
1704         }
1705
1706         set_gadget_data (gadget, dev);
1707         dev->gadget = gadget;
1708         gadget->ep0->driver_data = dev;
1709         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1710
1711         /* preallocate control response and buffer */
1712         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1713         if (!dev->req)
1714                 goto enomem;
1715         dev->req->context = NULL;
1716         dev->req->complete = epio_complete;
1717
1718         if (activate_ep_files (dev) < 0)
1719                 goto enomem;
1720
1721         INFO (dev, "bound to %s driver\n", gadget->name);
1722         spin_lock_irq(&dev->lock);
1723         dev->state = STATE_DEV_UNCONNECTED;
1724         spin_unlock_irq(&dev->lock);
1725         get_dev (dev);
1726         return 0;
1727
1728 enomem:
1729         gadgetfs_unbind (gadget);
1730         return -ENOMEM;
1731 }
1732
1733 static void
1734 gadgetfs_disconnect (struct usb_gadget *gadget)
1735 {
1736         struct dev_data         *dev = get_gadget_data (gadget);
1737
1738         spin_lock (&dev->lock);
1739         if (dev->state == STATE_DEV_UNCONNECTED)
1740                 goto exit;
1741         dev->state = STATE_DEV_UNCONNECTED;
1742
1743         INFO (dev, "disconnected\n");
1744         next_event (dev, GADGETFS_DISCONNECT);
1745         ep0_readable (dev);
1746 exit:
1747         spin_unlock (&dev->lock);
1748 }
1749
1750 static void
1751 gadgetfs_suspend (struct usb_gadget *gadget)
1752 {
1753         struct dev_data         *dev = get_gadget_data (gadget);
1754
1755         INFO (dev, "suspended from state %d\n", dev->state);
1756         spin_lock (&dev->lock);
1757         switch (dev->state) {
1758         case STATE_DEV_SETUP:           // VERY odd... host died??
1759         case STATE_DEV_CONNECTED:
1760         case STATE_DEV_UNCONNECTED:
1761                 next_event (dev, GADGETFS_SUSPEND);
1762                 ep0_readable (dev);
1763                 /* FALLTHROUGH */
1764         default:
1765                 break;
1766         }
1767         spin_unlock (&dev->lock);
1768 }
1769
1770 static struct usb_gadget_driver gadgetfs_driver = {
1771 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1772         .speed          = USB_SPEED_HIGH,
1773 #else
1774         .speed          = USB_SPEED_FULL,
1775 #endif
1776         .function       = (char *) driver_desc,
1777         .bind           = gadgetfs_bind,
1778         .unbind         = gadgetfs_unbind,
1779         .setup          = gadgetfs_setup,
1780         .disconnect     = gadgetfs_disconnect,
1781         .suspend        = gadgetfs_suspend,
1782
1783         .driver = {
1784                 .name           = (char *) shortname,
1785         },
1786 };
1787
1788 /*----------------------------------------------------------------------*/
1789
1790 static void gadgetfs_nop(struct usb_gadget *arg) { }
1791
1792 static int gadgetfs_probe (struct usb_gadget *gadget)
1793 {
1794         CHIP = gadget->name;
1795         return -EISNAM;
1796 }
1797
1798 static struct usb_gadget_driver probe_driver = {
1799         .speed          = USB_SPEED_HIGH,
1800         .bind           = gadgetfs_probe,
1801         .unbind         = gadgetfs_nop,
1802         .setup          = (void *)gadgetfs_nop,
1803         .disconnect     = gadgetfs_nop,
1804         .driver = {
1805                 .name           = "nop",
1806         },
1807 };
1808
1809
1810 /* DEVICE INITIALIZATION
1811  *
1812  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1813  *     status = write (fd, descriptors, sizeof descriptors)
1814  *
1815  * That write establishes the device configuration, so the kernel can
1816  * bind to the controller ... guaranteeing it can handle enumeration
1817  * at all necessary speeds.  Descriptor order is:
1818  *
1819  * . message tag (u32, host order) ... for now, must be zero; it
1820  *      would change to support features like multi-config devices
1821  * . full/low speed config ... all wTotalLength bytes (with interface,
1822  *      class, altsetting, endpoint, and other descriptors)
1823  * . high speed config ... all descriptors, for high speed operation;
1824  *      this one's optional except for high-speed hardware
1825  * . device descriptor
1826  *
1827  * Endpoints are not yet enabled. Drivers must wait until device
1828  * configuration and interface altsetting changes create
1829  * the need to configure (or unconfigure) them.
1830  *
1831  * After initialization, the device stays active for as long as that
1832  * $CHIP file is open.  Events must then be read from that descriptor,
1833  * such as configuration notifications.
1834  */
1835
1836 static int is_valid_config (struct usb_config_descriptor *config)
1837 {
1838         return config->bDescriptorType == USB_DT_CONFIG
1839                 && config->bLength == USB_DT_CONFIG_SIZE
1840                 && config->bConfigurationValue != 0
1841                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1842                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1843         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1844         /* FIXME check lengths: walk to end */
1845 }
1846
1847 static ssize_t
1848 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1849 {
1850         struct dev_data         *dev = fd->private_data;
1851         ssize_t                 value = len, length = len;
1852         unsigned                total;
1853         u32                     tag;
1854         char                    *kbuf;
1855
1856         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1857                 return -EINVAL;
1858
1859         /* we might need to change message format someday */
1860         if (copy_from_user (&tag, buf, 4))
1861                 return -EFAULT;
1862         if (tag != 0)
1863                 return -EINVAL;
1864         buf += 4;
1865         length -= 4;
1866
1867         kbuf = kmalloc (length, GFP_KERNEL);
1868         if (!kbuf)
1869                 return -ENOMEM;
1870         if (copy_from_user (kbuf, buf, length)) {
1871                 kfree (kbuf);
1872                 return -EFAULT;
1873         }
1874
1875         spin_lock_irq (&dev->lock);
1876         value = -EINVAL;
1877         if (dev->buf)
1878                 goto fail;
1879         dev->buf = kbuf;
1880
1881         /* full or low speed config */
1882         dev->config = (void *) kbuf;
1883         total = le16_to_cpup (&dev->config->wTotalLength);
1884         if (!is_valid_config (dev->config) || total >= length)
1885                 goto fail;
1886         kbuf += total;
1887         length -= total;
1888
1889         /* optional high speed config */
1890         if (kbuf [1] == USB_DT_CONFIG) {
1891                 dev->hs_config = (void *) kbuf;
1892                 total = le16_to_cpup (&dev->hs_config->wTotalLength);
1893                 if (!is_valid_config (dev->hs_config) || total >= length)
1894                         goto fail;
1895                 kbuf += total;
1896                 length -= total;
1897         }
1898
1899         /* could support multiple configs, using another encoding! */
1900
1901         /* device descriptor (tweaked for paranoia) */
1902         if (length != USB_DT_DEVICE_SIZE)
1903                 goto fail;
1904         dev->dev = (void *)kbuf;
1905         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1906                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1907                         || dev->dev->bNumConfigurations != 1)
1908                 goto fail;
1909         dev->dev->bNumConfigurations = 1;
1910         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1911
1912         /* triggers gadgetfs_bind(); then we can enumerate. */
1913         spin_unlock_irq (&dev->lock);
1914         value = usb_gadget_register_driver (&gadgetfs_driver);
1915         if (value != 0) {
1916                 kfree (dev->buf);
1917                 dev->buf = NULL;
1918         } else {
1919                 /* at this point "good" hardware has for the first time
1920                  * let the USB the host see us.  alternatively, if users
1921                  * unplug/replug that will clear all the error state.
1922                  *
1923                  * note:  everything running before here was guaranteed
1924                  * to choke driver model style diagnostics.  from here
1925                  * on, they can work ... except in cleanup paths that
1926                  * kick in after the ep0 descriptor is closed.
1927                  */
1928                 fd->f_op = &ep0_io_operations;
1929                 value = len;
1930         }
1931         return value;
1932
1933 fail:
1934         spin_unlock_irq (&dev->lock);
1935         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1936         kfree (dev->buf);
1937         dev->buf = NULL;
1938         return value;
1939 }
1940
1941 static int
1942 dev_open (struct inode *inode, struct file *fd)
1943 {
1944         struct dev_data         *dev = inode->i_private;
1945         int                     value = -EBUSY;
1946
1947         spin_lock_irq(&dev->lock);
1948         if (dev->state == STATE_DEV_DISABLED) {
1949                 dev->ev_next = 0;
1950                 dev->state = STATE_DEV_OPENED;
1951                 fd->private_data = dev;
1952                 get_dev (dev);
1953                 value = 0;
1954         }
1955         spin_unlock_irq(&dev->lock);
1956         return value;
1957 }
1958
1959 static const struct file_operations dev_init_operations = {
1960         .owner =        THIS_MODULE,
1961         .llseek =       no_llseek,
1962
1963         .open =         dev_open,
1964         .write =        dev_config,
1965         .fasync =       ep0_fasync,
1966         .ioctl =        dev_ioctl,
1967         .release =      dev_release,
1968 };
1969
1970 /*----------------------------------------------------------------------*/
1971
1972 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1973  *
1974  * Mounting the filesystem creates a controller file, used first for
1975  * device configuration then later for event monitoring.
1976  */
1977
1978
1979 /* FIXME PAM etc could set this security policy without mount options
1980  * if epfiles inherited ownership and permissons from ep0 ...
1981  */
1982
1983 static unsigned default_uid;
1984 static unsigned default_gid;
1985 static unsigned default_perm = S_IRUSR | S_IWUSR;
1986
1987 module_param (default_uid, uint, 0644);
1988 module_param (default_gid, uint, 0644);
1989 module_param (default_perm, uint, 0644);
1990
1991
1992 static struct inode *
1993 gadgetfs_make_inode (struct super_block *sb,
1994                 void *data, const struct file_operations *fops,
1995                 int mode)
1996 {
1997         struct inode *inode = new_inode (sb);
1998
1999         if (inode) {
2000                 inode->i_mode = mode;
2001                 inode->i_uid = default_uid;
2002                 inode->i_gid = default_gid;
2003                 inode->i_blocks = 0;
2004                 inode->i_atime = inode->i_mtime = inode->i_ctime
2005                                 = CURRENT_TIME;
2006                 inode->i_private = data;
2007                 inode->i_fop = fops;
2008         }
2009         return inode;
2010 }
2011
2012 /* creates in fs root directory, so non-renamable and non-linkable.
2013  * so inode and dentry are paired, until device reconfig.
2014  */
2015 static struct inode *
2016 gadgetfs_create_file (struct super_block *sb, char const *name,
2017                 void *data, const struct file_operations *fops,
2018                 struct dentry **dentry_p)
2019 {
2020         struct dentry   *dentry;
2021         struct inode    *inode;
2022
2023         dentry = d_alloc_name(sb->s_root, name);
2024         if (!dentry)
2025                 return NULL;
2026
2027         inode = gadgetfs_make_inode (sb, data, fops,
2028                         S_IFREG | (default_perm & S_IRWXUGO));
2029         if (!inode) {
2030                 dput(dentry);
2031                 return NULL;
2032         }
2033         d_add (dentry, inode);
2034         *dentry_p = dentry;
2035         return inode;
2036 }
2037
2038 static struct super_operations gadget_fs_operations = {
2039         .statfs =       simple_statfs,
2040         .drop_inode =   generic_delete_inode,
2041 };
2042
2043 static int
2044 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2045 {
2046         struct inode    *inode;
2047         struct dentry   *d;
2048         struct dev_data *dev;
2049
2050         if (the_device)
2051                 return -ESRCH;
2052
2053         /* fake probe to determine $CHIP */
2054         (void) usb_gadget_register_driver (&probe_driver);
2055         if (!CHIP)
2056                 return -ENODEV;
2057
2058         /* superblock */
2059         sb->s_blocksize = PAGE_CACHE_SIZE;
2060         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2061         sb->s_magic = GADGETFS_MAGIC;
2062         sb->s_op = &gadget_fs_operations;
2063         sb->s_time_gran = 1;
2064
2065         /* root inode */
2066         inode = gadgetfs_make_inode (sb,
2067                         NULL, &simple_dir_operations,
2068                         S_IFDIR | S_IRUGO | S_IXUGO);
2069         if (!inode)
2070                 goto enomem0;
2071         inode->i_op = &simple_dir_inode_operations;
2072         if (!(d = d_alloc_root (inode)))
2073                 goto enomem1;
2074         sb->s_root = d;
2075
2076         /* the ep0 file is named after the controller we expect;
2077          * user mode code can use it for sanity checks, like we do.
2078          */
2079         dev = dev_new ();
2080         if (!dev)
2081                 goto enomem2;
2082
2083         dev->sb = sb;
2084         if (!gadgetfs_create_file (sb, CHIP,
2085                                 dev, &dev_init_operations,
2086                                 &dev->dentry))
2087                 goto enomem3;
2088
2089         /* other endpoint files are available after hardware setup,
2090          * from binding to a controller.
2091          */
2092         the_device = dev;
2093         return 0;
2094
2095 enomem3:
2096         put_dev (dev);
2097 enomem2:
2098         dput (d);
2099 enomem1:
2100         iput (inode);
2101 enomem0:
2102         return -ENOMEM;
2103 }
2104
2105 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2106 static int
2107 gadgetfs_get_sb (struct file_system_type *t, int flags,
2108                 const char *path, void *opts, struct vfsmount *mnt)
2109 {
2110         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2111 }
2112
2113 static void
2114 gadgetfs_kill_sb (struct super_block *sb)
2115 {
2116         kill_litter_super (sb);
2117         if (the_device) {
2118                 put_dev (the_device);
2119                 the_device = NULL;
2120         }
2121 }
2122
2123 /*----------------------------------------------------------------------*/
2124
2125 static struct file_system_type gadgetfs_type = {
2126         .owner          = THIS_MODULE,
2127         .name           = shortname,
2128         .get_sb         = gadgetfs_get_sb,
2129         .kill_sb        = gadgetfs_kill_sb,
2130 };
2131
2132 /*----------------------------------------------------------------------*/
2133
2134 static int __init init (void)
2135 {
2136         int status;
2137
2138         status = register_filesystem (&gadgetfs_type);
2139         if (status == 0)
2140                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2141                         shortname, driver_desc);
2142         return status;
2143 }
2144 module_init (init);
2145
2146 static void __exit cleanup (void)
2147 {
2148         pr_debug ("unregister %s\n", shortname);
2149         unregister_filesystem (&gadgetfs_type);
2150 }
2151 module_exit (cleanup);
2152