USB: export <linux/usb_gadgetfs> as <linux/usb/gadgetfs.h>
[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         void                    *to_copy;
557         int                     i;
558
559         /* we "retry" to get the right mm context for this: */
560
561         /* copy stuff into user buffers */
562         total = priv->actual;
563         len = 0;
564         to_copy = priv->buf;
565         for (i=0; i < priv->nr_segs; i++) {
566                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
567
568                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
569                         if (len == 0)
570                                 len = -EFAULT;
571                         break;
572                 }
573
574                 total -= this;
575                 len += this;
576                 to_copy += this;
577                 if (total == 0)
578                         break;
579         }
580         kfree(priv->buf);
581         kfree(priv);
582         return len;
583 }
584
585 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
586 {
587         struct kiocb            *iocb = req->context;
588         struct kiocb_priv       *priv = iocb->private;
589         struct ep_data          *epdata = priv->epdata;
590
591         /* lock against disconnect (and ideally, cancel) */
592         spin_lock(&epdata->dev->lock);
593         priv->req = NULL;
594         priv->epdata = NULL;
595
596         /* if this was a write or a read returning no data then we
597          * don't need to copy anything to userspace, so we can
598          * complete the aio request immediately.
599          */
600         if (priv->iv == NULL || unlikely(req->actual == 0)) {
601                 kfree(req->buf);
602                 kfree(priv);
603                 iocb->private = NULL;
604                 /* aio_complete() reports bytes-transferred _and_ faults */
605                 aio_complete(iocb, req->actual ? req->actual : req->status,
606                                 req->status);
607         } else {
608                 /* retry() won't report both; so we hide some faults */
609                 if (unlikely(0 != req->status))
610                         DBG(epdata->dev, "%s fault %d len %d\n",
611                                 ep->name, req->status, req->actual);
612
613                 priv->buf = req->buf;
614                 priv->actual = req->actual;
615                 kick_iocb(iocb);
616         }
617         spin_unlock(&epdata->dev->lock);
618
619         usb_ep_free_request(ep, req);
620         put_ep(epdata);
621 }
622
623 static ssize_t
624 ep_aio_rwtail(
625         struct kiocb    *iocb,
626         char            *buf,
627         size_t          len,
628         struct ep_data  *epdata,
629         const struct iovec *iv,
630         unsigned long   nr_segs
631 )
632 {
633         struct kiocb_priv       *priv;
634         struct usb_request      *req;
635         ssize_t                 value;
636
637         priv = kmalloc(sizeof *priv, GFP_KERNEL);
638         if (!priv) {
639                 value = -ENOMEM;
640 fail:
641                 kfree(buf);
642                 return value;
643         }
644         iocb->private = priv;
645         priv->iv = iv;
646         priv->nr_segs = nr_segs;
647
648         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
649         if (unlikely(value < 0)) {
650                 kfree(priv);
651                 goto fail;
652         }
653
654         iocb->ki_cancel = ep_aio_cancel;
655         get_ep(epdata);
656         priv->epdata = epdata;
657         priv->actual = 0;
658
659         /* each kiocb is coupled to one usb_request, but we can't
660          * allocate or submit those if the host disconnected.
661          */
662         spin_lock_irq(&epdata->dev->lock);
663         if (likely(epdata->ep)) {
664                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
665                 if (likely(req)) {
666                         priv->req = req;
667                         req->buf = buf;
668                         req->length = len;
669                         req->complete = ep_aio_complete;
670                         req->context = iocb;
671                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
672                         if (unlikely(0 != value))
673                                 usb_ep_free_request(epdata->ep, req);
674                 } else
675                         value = -EAGAIN;
676         } else
677                 value = -ENODEV;
678         spin_unlock_irq(&epdata->dev->lock);
679
680         up(&epdata->lock);
681
682         if (unlikely(value)) {
683                 kfree(priv);
684                 put_ep(epdata);
685         } else
686                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
687         return value;
688 }
689
690 static ssize_t
691 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
692                 unsigned long nr_segs, loff_t o)
693 {
694         struct ep_data          *epdata = iocb->ki_filp->private_data;
695         char                    *buf;
696
697         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
698                 return -EINVAL;
699
700         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
701         if (unlikely(!buf))
702                 return -ENOMEM;
703
704         iocb->ki_retry = ep_aio_read_retry;
705         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
706 }
707
708 static ssize_t
709 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
710                 unsigned long nr_segs, loff_t o)
711 {
712         struct ep_data          *epdata = iocb->ki_filp->private_data;
713         char                    *buf;
714         size_t                  len = 0;
715         int                     i = 0;
716
717         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
718                 return -EINVAL;
719
720         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
721         if (unlikely(!buf))
722                 return -ENOMEM;
723
724         for (i=0; i < nr_segs; i++) {
725                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
726                                 iov[i].iov_len) != 0)) {
727                         kfree(buf);
728                         return -EFAULT;
729                 }
730                 len += iov[i].iov_len;
731         }
732         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
733 }
734
735 /*----------------------------------------------------------------------*/
736
737 /* used after endpoint configuration */
738 static const struct file_operations ep_io_operations = {
739         .owner =        THIS_MODULE,
740         .llseek =       no_llseek,
741
742         .read =         ep_read,
743         .write =        ep_write,
744         .ioctl =        ep_ioctl,
745         .release =      ep_release,
746
747         .aio_read =     ep_aio_read,
748         .aio_write =    ep_aio_write,
749 };
750
751 /* ENDPOINT INITIALIZATION
752  *
753  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
754  *     status = write (fd, descriptors, sizeof descriptors)
755  *
756  * That write establishes the endpoint configuration, configuring
757  * the controller to process bulk, interrupt, or isochronous transfers
758  * at the right maxpacket size, and so on.
759  *
760  * The descriptors are message type 1, identified by a host order u32
761  * at the beginning of what's written.  Descriptor order is: full/low
762  * speed descriptor, then optional high speed descriptor.
763  */
764 static ssize_t
765 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
766 {
767         struct ep_data          *data = fd->private_data;
768         struct usb_ep           *ep;
769         u32                     tag;
770         int                     value, length = len;
771
772         if ((value = down_interruptible (&data->lock)) < 0)
773                 return value;
774
775         if (data->state != STATE_EP_READY) {
776                 value = -EL2HLT;
777                 goto fail;
778         }
779
780         value = len;
781         if (len < USB_DT_ENDPOINT_SIZE + 4)
782                 goto fail0;
783
784         /* we might need to change message format someday */
785         if (copy_from_user (&tag, buf, 4)) {
786                 goto fail1;
787         }
788         if (tag != 1) {
789                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
790                 goto fail0;
791         }
792         buf += 4;
793         len -= 4;
794
795         /* NOTE:  audio endpoint extensions not accepted here;
796          * just don't include the extra bytes.
797          */
798
799         /* full/low speed descriptor, then high speed */
800         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
801                 goto fail1;
802         }
803         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
804                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
805                 goto fail0;
806         if (len != USB_DT_ENDPOINT_SIZE) {
807                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
808                         goto fail0;
809                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
810                                         USB_DT_ENDPOINT_SIZE)) {
811                         goto fail1;
812                 }
813                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
814                                 || data->hs_desc.bDescriptorType
815                                         != USB_DT_ENDPOINT) {
816                         DBG(data->dev, "config %s, bad hs length or type\n",
817                                         data->name);
818                         goto fail0;
819                 }
820         }
821
822         spin_lock_irq (&data->dev->lock);
823         if (data->dev->state == STATE_DEV_UNBOUND) {
824                 value = -ENOENT;
825                 goto gone;
826         } else if ((ep = data->ep) == NULL) {
827                 value = -ENODEV;
828                 goto gone;
829         }
830         switch (data->dev->gadget->speed) {
831         case USB_SPEED_LOW:
832         case USB_SPEED_FULL:
833                 value = usb_ep_enable (ep, &data->desc);
834                 if (value == 0)
835                         data->state = STATE_EP_ENABLED;
836                 break;
837 #ifdef  CONFIG_USB_GADGET_DUALSPEED
838         case USB_SPEED_HIGH:
839                 /* fails if caller didn't provide that descriptor... */
840                 value = usb_ep_enable (ep, &data->hs_desc);
841                 if (value == 0)
842                         data->state = STATE_EP_ENABLED;
843                 break;
844 #endif
845         default:
846                 DBG(data->dev, "unconnected, %s init abandoned\n",
847                                 data->name);
848                 value = -EINVAL;
849         }
850         if (value == 0) {
851                 fd->f_op = &ep_io_operations;
852                 value = length;
853         }
854 gone:
855         spin_unlock_irq (&data->dev->lock);
856         if (value < 0) {
857 fail:
858                 data->desc.bDescriptorType = 0;
859                 data->hs_desc.bDescriptorType = 0;
860         }
861         up (&data->lock);
862         return value;
863 fail0:
864         value = -EINVAL;
865         goto fail;
866 fail1:
867         value = -EFAULT;
868         goto fail;
869 }
870
871 static int
872 ep_open (struct inode *inode, struct file *fd)
873 {
874         struct ep_data          *data = inode->i_private;
875         int                     value = -EBUSY;
876
877         if (down_interruptible (&data->lock) != 0)
878                 return -EINTR;
879         spin_lock_irq (&data->dev->lock);
880         if (data->dev->state == STATE_DEV_UNBOUND)
881                 value = -ENOENT;
882         else if (data->state == STATE_EP_DISABLED) {
883                 value = 0;
884                 data->state = STATE_EP_READY;
885                 get_ep (data);
886                 fd->private_data = data;
887                 VDEBUG (data->dev, "%s ready\n", data->name);
888         } else
889                 DBG (data->dev, "%s state %d\n",
890                         data->name, data->state);
891         spin_unlock_irq (&data->dev->lock);
892         up (&data->lock);
893         return value;
894 }
895
896 /* used before endpoint configuration */
897 static const struct file_operations ep_config_operations = {
898         .owner =        THIS_MODULE,
899         .llseek =       no_llseek,
900
901         .open =         ep_open,
902         .write =        ep_config,
903         .release =      ep_release,
904 };
905
906 /*----------------------------------------------------------------------*/
907
908 /* EP0 IMPLEMENTATION can be partly in userspace.
909  *
910  * Drivers that use this facility receive various events, including
911  * control requests the kernel doesn't handle.  Drivers that don't
912  * use this facility may be too simple-minded for real applications.
913  */
914
915 static inline void ep0_readable (struct dev_data *dev)
916 {
917         wake_up (&dev->wait);
918         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
919 }
920
921 static void clean_req (struct usb_ep *ep, struct usb_request *req)
922 {
923         struct dev_data         *dev = ep->driver_data;
924
925         if (req->buf != dev->rbuf) {
926                 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
927                 req->buf = dev->rbuf;
928                 req->dma = DMA_ADDR_INVALID;
929         }
930         req->complete = epio_complete;
931         dev->setup_out_ready = 0;
932 }
933
934 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
935 {
936         struct dev_data         *dev = ep->driver_data;
937         unsigned long           flags;
938         int                     free = 1;
939
940         /* for control OUT, data must still get to userspace */
941         spin_lock_irqsave(&dev->lock, flags);
942         if (!dev->setup_in) {
943                 dev->setup_out_error = (req->status != 0);
944                 if (!dev->setup_out_error)
945                         free = 0;
946                 dev->setup_out_ready = 1;
947                 ep0_readable (dev);
948         }
949
950         /* clean up as appropriate */
951         if (free && req->buf != &dev->rbuf)
952                 clean_req (ep, req);
953         req->complete = epio_complete;
954         spin_unlock_irqrestore(&dev->lock, flags);
955 }
956
957 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
958 {
959         struct dev_data *dev = ep->driver_data;
960
961         if (dev->setup_out_ready) {
962                 DBG (dev, "ep0 request busy!\n");
963                 return -EBUSY;
964         }
965         if (len > sizeof (dev->rbuf))
966                 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
967         if (req->buf == 0) {
968                 req->buf = dev->rbuf;
969                 return -ENOMEM;
970         }
971         req->complete = ep0_complete;
972         req->length = len;
973         req->zero = 0;
974         return 0;
975 }
976
977 static ssize_t
978 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
979 {
980         struct dev_data                 *dev = fd->private_data;
981         ssize_t                         retval;
982         enum ep0_state                  state;
983
984         spin_lock_irq (&dev->lock);
985
986         /* report fd mode change before acting on it */
987         if (dev->setup_abort) {
988                 dev->setup_abort = 0;
989                 retval = -EIDRM;
990                 goto done;
991         }
992
993         /* control DATA stage */
994         if ((state = dev->state) == STATE_DEV_SETUP) {
995
996                 if (dev->setup_in) {            /* stall IN */
997                         VDEBUG(dev, "ep0in stall\n");
998                         (void) usb_ep_set_halt (dev->gadget->ep0);
999                         retval = -EL2HLT;
1000                         dev->state = STATE_DEV_CONNECTED;
1001
1002                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1003                         struct usb_ep           *ep = dev->gadget->ep0;
1004                         struct usb_request      *req = dev->req;
1005
1006                         if ((retval = setup_req (ep, req, 0)) == 0)
1007                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1008                         dev->state = STATE_DEV_CONNECTED;
1009
1010                         /* assume that was SET_CONFIGURATION */
1011                         if (dev->current_config) {
1012                                 unsigned power;
1013 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1014                                 if (dev->gadget->speed == USB_SPEED_HIGH)
1015                                         power = dev->hs_config->bMaxPower;
1016                                 else
1017 #endif
1018                                         power = dev->config->bMaxPower;
1019                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1020                         }
1021
1022                 } else {                        /* collect OUT data */
1023                         if ((fd->f_flags & O_NONBLOCK) != 0
1024                                         && !dev->setup_out_ready) {
1025                                 retval = -EAGAIN;
1026                                 goto done;
1027                         }
1028                         spin_unlock_irq (&dev->lock);
1029                         retval = wait_event_interruptible (dev->wait,
1030                                         dev->setup_out_ready != 0);
1031
1032                         /* FIXME state could change from under us */
1033                         spin_lock_irq (&dev->lock);
1034                         if (retval)
1035                                 goto done;
1036
1037                         if (dev->state != STATE_DEV_SETUP) {
1038                                 retval = -ECANCELED;
1039                                 goto done;
1040                         }
1041                         dev->state = STATE_DEV_CONNECTED;
1042
1043                         if (dev->setup_out_error)
1044                                 retval = -EIO;
1045                         else {
1046                                 len = min (len, (size_t)dev->req->actual);
1047 // FIXME don't call this with the spinlock held ...
1048                                 if (copy_to_user (buf, dev->req->buf, len))
1049                                         retval = -EFAULT;
1050                                 clean_req (dev->gadget->ep0, dev->req);
1051                                 /* NOTE userspace can't yet choose to stall */
1052                         }
1053                 }
1054                 goto done;
1055         }
1056
1057         /* else normal: return event data */
1058         if (len < sizeof dev->event [0]) {
1059                 retval = -EINVAL;
1060                 goto done;
1061         }
1062         len -= len % sizeof (struct usb_gadgetfs_event);
1063         dev->usermode_setup = 1;
1064
1065 scan:
1066         /* return queued events right away */
1067         if (dev->ev_next != 0) {
1068                 unsigned                i, n;
1069
1070                 n = len / sizeof (struct usb_gadgetfs_event);
1071                 if (dev->ev_next < n)
1072                         n = dev->ev_next;
1073
1074                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1075                 for (i = 0; i < n; i++) {
1076                         if (dev->event [i].type == GADGETFS_SETUP) {
1077                                 dev->state = STATE_DEV_SETUP;
1078                                 n = i + 1;
1079                                 break;
1080                         }
1081                 }
1082                 spin_unlock_irq (&dev->lock);
1083                 len = n * sizeof (struct usb_gadgetfs_event);
1084                 if (copy_to_user (buf, &dev->event, len))
1085                         retval = -EFAULT;
1086                 else
1087                         retval = len;
1088                 if (len > 0) {
1089                         /* NOTE this doesn't guard against broken drivers;
1090                          * concurrent ep0 readers may lose events.
1091                          */
1092                         spin_lock_irq (&dev->lock);
1093                         if (dev->ev_next > n) {
1094                                 memmove(&dev->event[0], &dev->event[n],
1095                                         sizeof (struct usb_gadgetfs_event)
1096                                                 * (dev->ev_next - n));
1097                         }
1098                         dev->ev_next -= n;
1099                         spin_unlock_irq (&dev->lock);
1100                 }
1101                 return retval;
1102         }
1103         if (fd->f_flags & O_NONBLOCK) {
1104                 retval = -EAGAIN;
1105                 goto done;
1106         }
1107
1108         switch (state) {
1109         default:
1110                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1111                 retval = -ESRCH;
1112                 break;
1113         case STATE_DEV_UNCONNECTED:
1114         case STATE_DEV_CONNECTED:
1115                 spin_unlock_irq (&dev->lock);
1116                 DBG (dev, "%s wait\n", __FUNCTION__);
1117
1118                 /* wait for events */
1119                 retval = wait_event_interruptible (dev->wait,
1120                                 dev->ev_next != 0);
1121                 if (retval < 0)
1122                         return retval;
1123                 spin_lock_irq (&dev->lock);
1124                 goto scan;
1125         }
1126
1127 done:
1128         spin_unlock_irq (&dev->lock);
1129         return retval;
1130 }
1131
1132 static struct usb_gadgetfs_event *
1133 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1134 {
1135         struct usb_gadgetfs_event       *event;
1136         unsigned                        i;
1137
1138         switch (type) {
1139         /* these events purge the queue */
1140         case GADGETFS_DISCONNECT:
1141                 if (dev->state == STATE_DEV_SETUP)
1142                         dev->setup_abort = 1;
1143                 // FALL THROUGH
1144         case GADGETFS_CONNECT:
1145                 dev->ev_next = 0;
1146                 break;
1147         case GADGETFS_SETUP:            /* previous request timed out */
1148         case GADGETFS_SUSPEND:          /* same effect */
1149                 /* these events can't be repeated */
1150                 for (i = 0; i != dev->ev_next; i++) {
1151                         if (dev->event [i].type != type)
1152                                 continue;
1153                         DBG(dev, "discard old event[%d] %d\n", i, type);
1154                         dev->ev_next--;
1155                         if (i == dev->ev_next)
1156                                 break;
1157                         /* indices start at zero, for simplicity */
1158                         memmove (&dev->event [i], &dev->event [i + 1],
1159                                 sizeof (struct usb_gadgetfs_event)
1160                                         * (dev->ev_next - i));
1161                 }
1162                 break;
1163         default:
1164                 BUG ();
1165         }
1166         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1167         event = &dev->event [dev->ev_next++];
1168         BUG_ON (dev->ev_next > N_EVENT);
1169         memset (event, 0, sizeof *event);
1170         event->type = type;
1171         return event;
1172 }
1173
1174 static ssize_t
1175 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1176 {
1177         struct dev_data         *dev = fd->private_data;
1178         ssize_t                 retval = -ESRCH;
1179
1180         spin_lock_irq (&dev->lock);
1181
1182         /* report fd mode change before acting on it */
1183         if (dev->setup_abort) {
1184                 dev->setup_abort = 0;
1185                 retval = -EIDRM;
1186
1187         /* data and/or status stage for control request */
1188         } else if (dev->state == STATE_DEV_SETUP) {
1189
1190                 /* IN DATA+STATUS caller makes len <= wLength */
1191                 if (dev->setup_in) {
1192                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1193                         if (retval == 0) {
1194                                 dev->state = STATE_DEV_CONNECTED;
1195                                 spin_unlock_irq (&dev->lock);
1196                                 if (copy_from_user (dev->req->buf, buf, len))
1197                                         retval = -EFAULT;
1198                                 else {
1199                                         if (len < dev->setup_wLength)
1200                                                 dev->req->zero = 1;
1201                                         retval = usb_ep_queue (
1202                                                 dev->gadget->ep0, dev->req,
1203                                                 GFP_KERNEL);
1204                                 }
1205                                 if (retval < 0) {
1206                                         spin_lock_irq (&dev->lock);
1207                                         clean_req (dev->gadget->ep0, dev->req);
1208                                         spin_unlock_irq (&dev->lock);
1209                                 } else
1210                                         retval = len;
1211
1212                                 return retval;
1213                         }
1214
1215                 /* can stall some OUT transfers */
1216                 } else if (dev->setup_can_stall) {
1217                         VDEBUG(dev, "ep0out stall\n");
1218                         (void) usb_ep_set_halt (dev->gadget->ep0);
1219                         retval = -EL2HLT;
1220                         dev->state = STATE_DEV_CONNECTED;
1221                 } else {
1222                         DBG(dev, "bogus ep0out stall!\n");
1223                 }
1224         } else
1225                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1226
1227         spin_unlock_irq (&dev->lock);
1228         return retval;
1229 }
1230
1231 static int
1232 ep0_fasync (int f, struct file *fd, int on)
1233 {
1234         struct dev_data         *dev = fd->private_data;
1235         // caller must F_SETOWN before signal delivery happens
1236         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1237         return fasync_helper (f, fd, on, &dev->fasync);
1238 }
1239
1240 static struct usb_gadget_driver gadgetfs_driver;
1241
1242 static int
1243 dev_release (struct inode *inode, struct file *fd)
1244 {
1245         struct dev_data         *dev = fd->private_data;
1246
1247         /* closing ep0 === shutdown all */
1248
1249         usb_gadget_unregister_driver (&gadgetfs_driver);
1250
1251         /* at this point "good" hardware has disconnected the
1252          * device from USB; the host won't see it any more.
1253          * alternatively, all host requests will time out.
1254          */
1255
1256         fasync_helper (-1, fd, 0, &dev->fasync);
1257         kfree (dev->buf);
1258         dev->buf = NULL;
1259         put_dev (dev);
1260
1261         /* other endpoints were all decoupled from this device */
1262         spin_lock_irq(&dev->lock);
1263         dev->state = STATE_DEV_DISABLED;
1264         spin_unlock_irq(&dev->lock);
1265         return 0;
1266 }
1267
1268 static unsigned int
1269 ep0_poll (struct file *fd, poll_table *wait)
1270 {
1271        struct dev_data         *dev = fd->private_data;
1272        int                     mask = 0;
1273
1274        poll_wait(fd, &dev->wait, wait);
1275
1276        spin_lock_irq (&dev->lock);
1277
1278        /* report fd mode change before acting on it */
1279        if (dev->setup_abort) {
1280                dev->setup_abort = 0;
1281                mask = POLLHUP;
1282                goto out;
1283        }
1284
1285        if (dev->state == STATE_DEV_SETUP) {
1286                if (dev->setup_in || dev->setup_can_stall)
1287                        mask = POLLOUT;
1288        } else {
1289                if (dev->ev_next != 0)
1290                        mask = POLLIN;
1291        }
1292 out:
1293        spin_unlock_irq(&dev->lock);
1294        return mask;
1295 }
1296
1297 static int dev_ioctl (struct inode *inode, struct file *fd,
1298                 unsigned code, unsigned long value)
1299 {
1300         struct dev_data         *dev = fd->private_data;
1301         struct usb_gadget       *gadget = dev->gadget;
1302
1303         if (gadget->ops->ioctl)
1304                 return gadget->ops->ioctl (gadget, code, value);
1305         return -ENOTTY;
1306 }
1307
1308 /* used after device configuration */
1309 static const struct file_operations ep0_io_operations = {
1310         .owner =        THIS_MODULE,
1311         .llseek =       no_llseek,
1312
1313         .read =         ep0_read,
1314         .write =        ep0_write,
1315         .fasync =       ep0_fasync,
1316         .poll =         ep0_poll,
1317         .ioctl =        dev_ioctl,
1318         .release =      dev_release,
1319 };
1320
1321 /*----------------------------------------------------------------------*/
1322
1323 /* The in-kernel gadget driver handles most ep0 issues, in particular
1324  * enumerating the single configuration (as provided from user space).
1325  *
1326  * Unrecognized ep0 requests may be handled in user space.
1327  */
1328
1329 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1330 static void make_qualifier (struct dev_data *dev)
1331 {
1332         struct usb_qualifier_descriptor         qual;
1333         struct usb_device_descriptor            *desc;
1334
1335         qual.bLength = sizeof qual;
1336         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1337         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1338
1339         desc = dev->dev;
1340         qual.bDeviceClass = desc->bDeviceClass;
1341         qual.bDeviceSubClass = desc->bDeviceSubClass;
1342         qual.bDeviceProtocol = desc->bDeviceProtocol;
1343
1344         /* assumes ep0 uses the same value for both speeds ... */
1345         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1346
1347         qual.bNumConfigurations = 1;
1348         qual.bRESERVED = 0;
1349
1350         memcpy (dev->rbuf, &qual, sizeof qual);
1351 }
1352 #endif
1353
1354 static int
1355 config_buf (struct dev_data *dev, u8 type, unsigned index)
1356 {
1357         int             len;
1358 #ifdef CONFIG_USB_GADGET_DUALSPEED
1359         int             hs;
1360 #endif
1361
1362         /* only one configuration */
1363         if (index > 0)
1364                 return -EINVAL;
1365
1366 #ifdef CONFIG_USB_GADGET_DUALSPEED
1367         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1368         if (type == USB_DT_OTHER_SPEED_CONFIG)
1369                 hs = !hs;
1370         if (hs) {
1371                 dev->req->buf = dev->hs_config;
1372                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1373         } else
1374 #endif
1375         {
1376                 dev->req->buf = dev->config;
1377                 len = le16_to_cpu(dev->config->wTotalLength);
1378         }
1379         ((u8 *)dev->req->buf) [1] = type;
1380         return len;
1381 }
1382
1383 static int
1384 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1385 {
1386         struct dev_data                 *dev = get_gadget_data (gadget);
1387         struct usb_request              *req = dev->req;
1388         int                             value = -EOPNOTSUPP;
1389         struct usb_gadgetfs_event       *event;
1390         u16                             w_value = le16_to_cpu(ctrl->wValue);
1391         u16                             w_length = le16_to_cpu(ctrl->wLength);
1392
1393         spin_lock (&dev->lock);
1394         dev->setup_abort = 0;
1395         if (dev->state == STATE_DEV_UNCONNECTED) {
1396 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1397                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1398                         spin_unlock(&dev->lock);
1399                         ERROR (dev, "no high speed config??\n");
1400                         return -EINVAL;
1401                 }
1402 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1403
1404                 dev->state = STATE_DEV_CONNECTED;
1405                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1406
1407                 INFO (dev, "connected\n");
1408                 event = next_event (dev, GADGETFS_CONNECT);
1409                 event->u.speed = gadget->speed;
1410                 ep0_readable (dev);
1411
1412         /* host may have given up waiting for response.  we can miss control
1413          * requests handled lower down (device/endpoint status and features);
1414          * then ep0_{read,write} will report the wrong status. controller
1415          * driver will have aborted pending i/o.
1416          */
1417         } else if (dev->state == STATE_DEV_SETUP)
1418                 dev->setup_abort = 1;
1419
1420         req->buf = dev->rbuf;
1421         req->dma = DMA_ADDR_INVALID;
1422         req->context = NULL;
1423         value = -EOPNOTSUPP;
1424         switch (ctrl->bRequest) {
1425
1426         case USB_REQ_GET_DESCRIPTOR:
1427                 if (ctrl->bRequestType != USB_DIR_IN)
1428                         goto unrecognized;
1429                 switch (w_value >> 8) {
1430
1431                 case USB_DT_DEVICE:
1432                         value = min (w_length, (u16) sizeof *dev->dev);
1433                         req->buf = dev->dev;
1434                         break;
1435 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1436                 case USB_DT_DEVICE_QUALIFIER:
1437                         if (!dev->hs_config)
1438                                 break;
1439                         value = min (w_length, (u16)
1440                                 sizeof (struct usb_qualifier_descriptor));
1441                         make_qualifier (dev);
1442                         break;
1443                 case USB_DT_OTHER_SPEED_CONFIG:
1444                         // FALLTHROUGH
1445 #endif
1446                 case USB_DT_CONFIG:
1447                         value = config_buf (dev,
1448                                         w_value >> 8,
1449                                         w_value & 0xff);
1450                         if (value >= 0)
1451                                 value = min (w_length, (u16) value);
1452                         break;
1453                 case USB_DT_STRING:
1454                         goto unrecognized;
1455
1456                 default:                // all others are errors
1457                         break;
1458                 }
1459                 break;
1460
1461         /* currently one config, two speeds */
1462         case USB_REQ_SET_CONFIGURATION:
1463                 if (ctrl->bRequestType != 0)
1464                         break;
1465                 if (0 == (u8) w_value) {
1466                         value = 0;
1467                         dev->current_config = 0;
1468                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1469                         // user mode expected to disable endpoints
1470                 } else {
1471                         u8      config, power;
1472 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1473                         if (gadget->speed == USB_SPEED_HIGH) {
1474                                 config = dev->hs_config->bConfigurationValue;
1475                                 power = dev->hs_config->bMaxPower;
1476                         } else
1477 #endif
1478                         {
1479                                 config = dev->config->bConfigurationValue;
1480                                 power = dev->config->bMaxPower;
1481                         }
1482
1483                         if (config == (u8) w_value) {
1484                                 value = 0;
1485                                 dev->current_config = config;
1486                                 usb_gadget_vbus_draw(gadget, 2 * power);
1487                         }
1488                 }
1489
1490                 /* report SET_CONFIGURATION like any other control request,
1491                  * except that usermode may not stall this.  the next
1492                  * request mustn't be allowed start until this finishes:
1493                  * endpoints and threads set up, etc.
1494                  *
1495                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1496                  * has bad/racey automagic that prevents synchronizing here.
1497                  * even kernel mode drivers often miss them.
1498                  */
1499                 if (value == 0) {
1500                         INFO (dev, "configuration #%d\n", dev->current_config);
1501                         if (dev->usermode_setup) {
1502                                 dev->setup_can_stall = 0;
1503                                 goto delegate;
1504                         }
1505                 }
1506                 break;
1507
1508 #ifndef CONFIG_USB_GADGET_PXA2XX
1509         /* PXA automagically handles this request too */
1510         case USB_REQ_GET_CONFIGURATION:
1511                 if (ctrl->bRequestType != 0x80)
1512                         break;
1513                 *(u8 *)req->buf = dev->current_config;
1514                 value = min (w_length, (u16) 1);
1515                 break;
1516 #endif
1517
1518         default:
1519 unrecognized:
1520                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1521                         dev->usermode_setup ? "delegate" : "fail",
1522                         ctrl->bRequestType, ctrl->bRequest,
1523                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1524
1525                 /* if there's an ep0 reader, don't stall */
1526                 if (dev->usermode_setup) {
1527                         dev->setup_can_stall = 1;
1528 delegate:
1529                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1530                                                 ? 1 : 0;
1531                         dev->setup_wLength = w_length;
1532                         dev->setup_out_ready = 0;
1533                         dev->setup_out_error = 0;
1534                         value = 0;
1535
1536                         /* read DATA stage for OUT right away */
1537                         if (unlikely (!dev->setup_in && w_length)) {
1538                                 value = setup_req (gadget->ep0, dev->req,
1539                                                         w_length);
1540                                 if (value < 0)
1541                                         break;
1542                                 value = usb_ep_queue (gadget->ep0, dev->req,
1543                                                         GFP_ATOMIC);
1544                                 if (value < 0) {
1545                                         clean_req (gadget->ep0, dev->req);
1546                                         break;
1547                                 }
1548
1549                                 /* we can't currently stall these */
1550                                 dev->setup_can_stall = 0;
1551                         }
1552
1553                         /* state changes when reader collects event */
1554                         event = next_event (dev, GADGETFS_SETUP);
1555                         event->u.setup = *ctrl;
1556                         ep0_readable (dev);
1557                         spin_unlock (&dev->lock);
1558                         return 0;
1559                 }
1560         }
1561
1562         /* proceed with data transfer and status phases? */
1563         if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1564                 req->length = value;
1565                 req->zero = value < w_length;
1566                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1567                 if (value < 0) {
1568                         DBG (dev, "ep_queue --> %d\n", value);
1569                         req->status = 0;
1570                 }
1571         }
1572
1573         /* device stalls when value < 0 */
1574         spin_unlock (&dev->lock);
1575         return value;
1576 }
1577
1578 static void destroy_ep_files (struct dev_data *dev)
1579 {
1580         struct list_head        *entry, *tmp;
1581
1582         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1583
1584         /* dev->state must prevent interference */
1585 restart:
1586         spin_lock_irq (&dev->lock);
1587         list_for_each_safe (entry, tmp, &dev->epfiles) {
1588                 struct ep_data  *ep;
1589                 struct inode    *parent;
1590                 struct dentry   *dentry;
1591
1592                 /* break link to FS */
1593                 ep = list_entry (entry, struct ep_data, epfiles);
1594                 list_del_init (&ep->epfiles);
1595                 dentry = ep->dentry;
1596                 ep->dentry = NULL;
1597                 parent = dentry->d_parent->d_inode;
1598
1599                 /* break link to controller */
1600                 if (ep->state == STATE_EP_ENABLED)
1601                         (void) usb_ep_disable (ep->ep);
1602                 ep->state = STATE_EP_UNBOUND;
1603                 usb_ep_free_request (ep->ep, ep->req);
1604                 ep->ep = NULL;
1605                 wake_up (&ep->wait);
1606                 put_ep (ep);
1607
1608                 spin_unlock_irq (&dev->lock);
1609
1610                 /* break link to dcache */
1611                 mutex_lock (&parent->i_mutex);
1612                 d_delete (dentry);
1613                 dput (dentry);
1614                 mutex_unlock (&parent->i_mutex);
1615
1616                 /* fds may still be open */
1617                 goto restart;
1618         }
1619         spin_unlock_irq (&dev->lock);
1620 }
1621
1622
1623 static struct inode *
1624 gadgetfs_create_file (struct super_block *sb, char const *name,
1625                 void *data, const struct file_operations *fops,
1626                 struct dentry **dentry_p);
1627
1628 static int activate_ep_files (struct dev_data *dev)
1629 {
1630         struct usb_ep   *ep;
1631         struct ep_data  *data;
1632
1633         gadget_for_each_ep (ep, dev->gadget) {
1634
1635                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1636                 if (!data)
1637                         goto enomem0;
1638                 data->state = STATE_EP_DISABLED;
1639                 init_MUTEX (&data->lock);
1640                 init_waitqueue_head (&data->wait);
1641
1642                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1643                 atomic_set (&data->count, 1);
1644                 data->dev = dev;
1645                 get_dev (dev);
1646
1647                 data->ep = ep;
1648                 ep->driver_data = data;
1649
1650                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1651                 if (!data->req)
1652                         goto enomem1;
1653
1654                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1655                                 data, &ep_config_operations,
1656                                 &data->dentry);
1657                 if (!data->inode)
1658                         goto enomem2;
1659                 list_add_tail (&data->epfiles, &dev->epfiles);
1660         }
1661         return 0;
1662
1663 enomem2:
1664         usb_ep_free_request (ep, data->req);
1665 enomem1:
1666         put_dev (dev);
1667         kfree (data);
1668 enomem0:
1669         DBG (dev, "%s enomem\n", __FUNCTION__);
1670         destroy_ep_files (dev);
1671         return -ENOMEM;
1672 }
1673
1674 static void
1675 gadgetfs_unbind (struct usb_gadget *gadget)
1676 {
1677         struct dev_data         *dev = get_gadget_data (gadget);
1678
1679         DBG (dev, "%s\n", __FUNCTION__);
1680
1681         spin_lock_irq (&dev->lock);
1682         dev->state = STATE_DEV_UNBOUND;
1683         spin_unlock_irq (&dev->lock);
1684
1685         destroy_ep_files (dev);
1686         gadget->ep0->driver_data = NULL;
1687         set_gadget_data (gadget, NULL);
1688
1689         /* we've already been disconnected ... no i/o is active */
1690         if (dev->req)
1691                 usb_ep_free_request (gadget->ep0, dev->req);
1692         DBG (dev, "%s done\n", __FUNCTION__);
1693         put_dev (dev);
1694 }
1695
1696 static struct dev_data          *the_device;
1697
1698 static int
1699 gadgetfs_bind (struct usb_gadget *gadget)
1700 {
1701         struct dev_data         *dev = the_device;
1702
1703         if (!dev)
1704                 return -ESRCH;
1705         if (0 != strcmp (CHIP, gadget->name)) {
1706                 printk (KERN_ERR "%s expected %s controller not %s\n",
1707                         shortname, CHIP, gadget->name);
1708                 return -ENODEV;
1709         }
1710
1711         set_gadget_data (gadget, dev);
1712         dev->gadget = gadget;
1713         gadget->ep0->driver_data = dev;
1714         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
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
1743         spin_lock (&dev->lock);
1744         if (dev->state == STATE_DEV_UNCONNECTED)
1745                 goto exit;
1746         dev->state = STATE_DEV_UNCONNECTED;
1747
1748         INFO (dev, "disconnected\n");
1749         next_event (dev, GADGETFS_DISCONNECT);
1750         ep0_readable (dev);
1751 exit:
1752         spin_unlock (&dev->lock);
1753 }
1754
1755 static void
1756 gadgetfs_suspend (struct usb_gadget *gadget)
1757 {
1758         struct dev_data         *dev = get_gadget_data (gadget);
1759
1760         INFO (dev, "suspended from state %d\n", dev->state);
1761         spin_lock (&dev->lock);
1762         switch (dev->state) {
1763         case STATE_DEV_SETUP:           // VERY odd... host died??
1764         case STATE_DEV_CONNECTED:
1765         case STATE_DEV_UNCONNECTED:
1766                 next_event (dev, GADGETFS_SUSPEND);
1767                 ep0_readable (dev);
1768                 /* FALLTHROUGH */
1769         default:
1770                 break;
1771         }
1772         spin_unlock (&dev->lock);
1773 }
1774
1775 static struct usb_gadget_driver gadgetfs_driver = {
1776 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1777         .speed          = USB_SPEED_HIGH,
1778 #else
1779         .speed          = USB_SPEED_FULL,
1780 #endif
1781         .function       = (char *) driver_desc,
1782         .bind           = gadgetfs_bind,
1783         .unbind         = gadgetfs_unbind,
1784         .setup          = gadgetfs_setup,
1785         .disconnect     = gadgetfs_disconnect,
1786         .suspend        = gadgetfs_suspend,
1787
1788         .driver = {
1789                 .name           = (char *) shortname,
1790         },
1791 };
1792
1793 /*----------------------------------------------------------------------*/
1794
1795 static void gadgetfs_nop(struct usb_gadget *arg) { }
1796
1797 static int gadgetfs_probe (struct usb_gadget *gadget)
1798 {
1799         CHIP = gadget->name;
1800         return -EISNAM;
1801 }
1802
1803 static struct usb_gadget_driver probe_driver = {
1804         .speed          = USB_SPEED_HIGH,
1805         .bind           = gadgetfs_probe,
1806         .unbind         = gadgetfs_nop,
1807         .setup          = (void *)gadgetfs_nop,
1808         .disconnect     = gadgetfs_nop,
1809         .driver = {
1810                 .name           = "nop",
1811         },
1812 };
1813
1814
1815 /* DEVICE INITIALIZATION
1816  *
1817  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1818  *     status = write (fd, descriptors, sizeof descriptors)
1819  *
1820  * That write establishes the device configuration, so the kernel can
1821  * bind to the controller ... guaranteeing it can handle enumeration
1822  * at all necessary speeds.  Descriptor order is:
1823  *
1824  * . message tag (u32, host order) ... for now, must be zero; it
1825  *      would change to support features like multi-config devices
1826  * . full/low speed config ... all wTotalLength bytes (with interface,
1827  *      class, altsetting, endpoint, and other descriptors)
1828  * . high speed config ... all descriptors, for high speed operation;
1829  *      this one's optional except for high-speed hardware
1830  * . device descriptor
1831  *
1832  * Endpoints are not yet enabled. Drivers must wait until device
1833  * configuration and interface altsetting changes create
1834  * the need to configure (or unconfigure) them.
1835  *
1836  * After initialization, the device stays active for as long as that
1837  * $CHIP file is open.  Events must then be read from that descriptor,
1838  * such as configuration notifications.
1839  */
1840
1841 static int is_valid_config (struct usb_config_descriptor *config)
1842 {
1843         return config->bDescriptorType == USB_DT_CONFIG
1844                 && config->bLength == USB_DT_CONFIG_SIZE
1845                 && config->bConfigurationValue != 0
1846                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1847                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1848         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1849         /* FIXME check lengths: walk to end */
1850 }
1851
1852 static ssize_t
1853 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1854 {
1855         struct dev_data         *dev = fd->private_data;
1856         ssize_t                 value = len, length = len;
1857         unsigned                total;
1858         u32                     tag;
1859         char                    *kbuf;
1860
1861         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1862                 return -EINVAL;
1863
1864         /* we might need to change message format someday */
1865         if (copy_from_user (&tag, buf, 4))
1866                 return -EFAULT;
1867         if (tag != 0)
1868                 return -EINVAL;
1869         buf += 4;
1870         length -= 4;
1871
1872         kbuf = kmalloc (length, GFP_KERNEL);
1873         if (!kbuf)
1874                 return -ENOMEM;
1875         if (copy_from_user (kbuf, buf, length)) {
1876                 kfree (kbuf);
1877                 return -EFAULT;
1878         }
1879
1880         spin_lock_irq (&dev->lock);
1881         value = -EINVAL;
1882         if (dev->buf)
1883                 goto fail;
1884         dev->buf = kbuf;
1885
1886         /* full or low speed config */
1887         dev->config = (void *) kbuf;
1888         total = le16_to_cpu(dev->config->wTotalLength);
1889         if (!is_valid_config (dev->config) || total >= length)
1890                 goto fail;
1891         kbuf += total;
1892         length -= total;
1893
1894         /* optional high speed config */
1895         if (kbuf [1] == USB_DT_CONFIG) {
1896                 dev->hs_config = (void *) kbuf;
1897                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1898                 if (!is_valid_config (dev->hs_config) || total >= length)
1899                         goto fail;
1900                 kbuf += total;
1901                 length -= total;
1902         }
1903
1904         /* could support multiple configs, using another encoding! */
1905
1906         /* device descriptor (tweaked for paranoia) */
1907         if (length != USB_DT_DEVICE_SIZE)
1908                 goto fail;
1909         dev->dev = (void *)kbuf;
1910         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1911                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1912                         || dev->dev->bNumConfigurations != 1)
1913                 goto fail;
1914         dev->dev->bNumConfigurations = 1;
1915         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1916
1917         /* triggers gadgetfs_bind(); then we can enumerate. */
1918         spin_unlock_irq (&dev->lock);
1919         value = usb_gadget_register_driver (&gadgetfs_driver);
1920         if (value != 0) {
1921                 kfree (dev->buf);
1922                 dev->buf = NULL;
1923         } else {
1924                 /* at this point "good" hardware has for the first time
1925                  * let the USB the host see us.  alternatively, if users
1926                  * unplug/replug that will clear all the error state.
1927                  *
1928                  * note:  everything running before here was guaranteed
1929                  * to choke driver model style diagnostics.  from here
1930                  * on, they can work ... except in cleanup paths that
1931                  * kick in after the ep0 descriptor is closed.
1932                  */
1933                 fd->f_op = &ep0_io_operations;
1934                 value = len;
1935         }
1936         return value;
1937
1938 fail:
1939         spin_unlock_irq (&dev->lock);
1940         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1941         kfree (dev->buf);
1942         dev->buf = NULL;
1943         return value;
1944 }
1945
1946 static int
1947 dev_open (struct inode *inode, struct file *fd)
1948 {
1949         struct dev_data         *dev = inode->i_private;
1950         int                     value = -EBUSY;
1951
1952         spin_lock_irq(&dev->lock);
1953         if (dev->state == STATE_DEV_DISABLED) {
1954                 dev->ev_next = 0;
1955                 dev->state = STATE_DEV_OPENED;
1956                 fd->private_data = dev;
1957                 get_dev (dev);
1958                 value = 0;
1959         }
1960         spin_unlock_irq(&dev->lock);
1961         return value;
1962 }
1963
1964 static const struct file_operations dev_init_operations = {
1965         .owner =        THIS_MODULE,
1966         .llseek =       no_llseek,
1967
1968         .open =         dev_open,
1969         .write =        dev_config,
1970         .fasync =       ep0_fasync,
1971         .ioctl =        dev_ioctl,
1972         .release =      dev_release,
1973 };
1974
1975 /*----------------------------------------------------------------------*/
1976
1977 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1978  *
1979  * Mounting the filesystem creates a controller file, used first for
1980  * device configuration then later for event monitoring.
1981  */
1982
1983
1984 /* FIXME PAM etc could set this security policy without mount options
1985  * if epfiles inherited ownership and permissons from ep0 ...
1986  */
1987
1988 static unsigned default_uid;
1989 static unsigned default_gid;
1990 static unsigned default_perm = S_IRUSR | S_IWUSR;
1991
1992 module_param (default_uid, uint, 0644);
1993 module_param (default_gid, uint, 0644);
1994 module_param (default_perm, uint, 0644);
1995
1996
1997 static struct inode *
1998 gadgetfs_make_inode (struct super_block *sb,
1999                 void *data, const struct file_operations *fops,
2000                 int mode)
2001 {
2002         struct inode *inode = new_inode (sb);
2003
2004         if (inode) {
2005                 inode->i_mode = mode;
2006                 inode->i_uid = default_uid;
2007                 inode->i_gid = default_gid;
2008                 inode->i_blocks = 0;
2009                 inode->i_atime = inode->i_mtime = inode->i_ctime
2010                                 = CURRENT_TIME;
2011                 inode->i_private = data;
2012                 inode->i_fop = fops;
2013         }
2014         return inode;
2015 }
2016
2017 /* creates in fs root directory, so non-renamable and non-linkable.
2018  * so inode and dentry are paired, until device reconfig.
2019  */
2020 static struct inode *
2021 gadgetfs_create_file (struct super_block *sb, char const *name,
2022                 void *data, const struct file_operations *fops,
2023                 struct dentry **dentry_p)
2024 {
2025         struct dentry   *dentry;
2026         struct inode    *inode;
2027
2028         dentry = d_alloc_name(sb->s_root, name);
2029         if (!dentry)
2030                 return NULL;
2031
2032         inode = gadgetfs_make_inode (sb, data, fops,
2033                         S_IFREG | (default_perm & S_IRWXUGO));
2034         if (!inode) {
2035                 dput(dentry);
2036                 return NULL;
2037         }
2038         d_add (dentry, inode);
2039         *dentry_p = dentry;
2040         return inode;
2041 }
2042
2043 static struct super_operations gadget_fs_operations = {
2044         .statfs =       simple_statfs,
2045         .drop_inode =   generic_delete_inode,
2046 };
2047
2048 static int
2049 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2050 {
2051         struct inode    *inode;
2052         struct dentry   *d;
2053         struct dev_data *dev;
2054
2055         if (the_device)
2056                 return -ESRCH;
2057
2058         /* fake probe to determine $CHIP */
2059         (void) usb_gadget_register_driver (&probe_driver);
2060         if (!CHIP)
2061                 return -ENODEV;
2062
2063         /* superblock */
2064         sb->s_blocksize = PAGE_CACHE_SIZE;
2065         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2066         sb->s_magic = GADGETFS_MAGIC;
2067         sb->s_op = &gadget_fs_operations;
2068         sb->s_time_gran = 1;
2069
2070         /* root inode */
2071         inode = gadgetfs_make_inode (sb,
2072                         NULL, &simple_dir_operations,
2073                         S_IFDIR | S_IRUGO | S_IXUGO);
2074         if (!inode)
2075                 goto enomem0;
2076         inode->i_op = &simple_dir_inode_operations;
2077         if (!(d = d_alloc_root (inode)))
2078                 goto enomem1;
2079         sb->s_root = d;
2080
2081         /* the ep0 file is named after the controller we expect;
2082          * user mode code can use it for sanity checks, like we do.
2083          */
2084         dev = dev_new ();
2085         if (!dev)
2086                 goto enomem2;
2087
2088         dev->sb = sb;
2089         if (!gadgetfs_create_file (sb, CHIP,
2090                                 dev, &dev_init_operations,
2091                                 &dev->dentry))
2092                 goto enomem3;
2093
2094         /* other endpoint files are available after hardware setup,
2095          * from binding to a controller.
2096          */
2097         the_device = dev;
2098         return 0;
2099
2100 enomem3:
2101         put_dev (dev);
2102 enomem2:
2103         dput (d);
2104 enomem1:
2105         iput (inode);
2106 enomem0:
2107         return -ENOMEM;
2108 }
2109
2110 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2111 static int
2112 gadgetfs_get_sb (struct file_system_type *t, int flags,
2113                 const char *path, void *opts, struct vfsmount *mnt)
2114 {
2115         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2116 }
2117
2118 static void
2119 gadgetfs_kill_sb (struct super_block *sb)
2120 {
2121         kill_litter_super (sb);
2122         if (the_device) {
2123                 put_dev (the_device);
2124                 the_device = NULL;
2125         }
2126 }
2127
2128 /*----------------------------------------------------------------------*/
2129
2130 static struct file_system_type gadgetfs_type = {
2131         .owner          = THIS_MODULE,
2132         .name           = shortname,
2133         .get_sb         = gadgetfs_get_sb,
2134         .kill_sb        = gadgetfs_kill_sb,
2135 };
2136
2137 /*----------------------------------------------------------------------*/
2138
2139 static int __init init (void)
2140 {
2141         int status;
2142
2143         status = register_filesystem (&gadgetfs_type);
2144         if (status == 0)
2145                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2146                         shortname, driver_desc);
2147         return status;
2148 }
2149 module_init (init);
2150
2151 static void __exit cleanup (void)
2152 {
2153         pr_debug ("unregister %s\n", shortname);
2154         unregister_filesystem (&gadgetfs_type);
2155 }
2156 module_exit (cleanup);
2157