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[linux-3.10.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 VERBOSE_DEBUG */
24
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/fs.h>
28 #include <linux/pagemap.h>
29 #include <linux/uts.h>
30 #include <linux/wait.h>
31 #include <linux/compiler.h>
32 #include <asm/uaccess.h>
33 #include <linux/sched.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 mutex                    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_DEBUG
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 INFO(dev,fmt,args...) \
266         xprintk(dev , KERN_INFO , fmt , ## args)
267
268
269 /*----------------------------------------------------------------------*/
270
271 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
272  *
273  * After opening, configure non-control endpoints.  Then use normal
274  * stream read() and write() requests; and maybe ioctl() to get more
275  * precise FIFO status when recovering from cancellation.
276  */
277
278 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
279 {
280         struct ep_data  *epdata = ep->driver_data;
281
282         if (!req->context)
283                 return;
284         if (req->status)
285                 epdata->status = req->status;
286         else
287                 epdata->status = req->actual;
288         complete ((struct completion *)req->context);
289 }
290
291 /* tasklock endpoint, returning when it's connected.
292  * still need dev->lock to use epdata->ep.
293  */
294 static int
295 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
296 {
297         int     val;
298
299         if (f_flags & O_NONBLOCK) {
300                 if (!mutex_trylock(&epdata->lock))
301                         goto nonblock;
302                 if (epdata->state != STATE_EP_ENABLED) {
303                         mutex_unlock(&epdata->lock);
304 nonblock:
305                         val = -EAGAIN;
306                 } else
307                         val = 0;
308                 return val;
309         }
310
311         val = mutex_lock_interruptible(&epdata->lock);
312         if (val < 0)
313                 return val;
314
315         switch (epdata->state) {
316         case STATE_EP_ENABLED:
317                 break;
318         // case STATE_EP_DISABLED:              /* "can't happen" */
319         // case STATE_EP_READY:                 /* "can't happen" */
320         default:                                /* error! */
321                 pr_debug ("%s: ep %p not available, state %d\n",
322                                 shortname, epdata, epdata->state);
323                 // FALLTHROUGH
324         case STATE_EP_UNBOUND:                  /* clean disconnect */
325                 val = -ENODEV;
326                 mutex_unlock(&epdata->lock);
327         }
328         return val;
329 }
330
331 static ssize_t
332 ep_io (struct ep_data *epdata, void *buf, unsigned len)
333 {
334         DECLARE_COMPLETION_ONSTACK (done);
335         int value;
336
337         spin_lock_irq (&epdata->dev->lock);
338         if (likely (epdata->ep != NULL)) {
339                 struct usb_request      *req = epdata->req;
340
341                 req->context = &done;
342                 req->complete = epio_complete;
343                 req->buf = buf;
344                 req->length = len;
345                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
346         } else
347                 value = -ENODEV;
348         spin_unlock_irq (&epdata->dev->lock);
349
350         if (likely (value == 0)) {
351                 value = wait_event_interruptible (done.wait, done.done);
352                 if (value != 0) {
353                         spin_lock_irq (&epdata->dev->lock);
354                         if (likely (epdata->ep != NULL)) {
355                                 DBG (epdata->dev, "%s i/o interrupted\n",
356                                                 epdata->name);
357                                 usb_ep_dequeue (epdata->ep, epdata->req);
358                                 spin_unlock_irq (&epdata->dev->lock);
359
360                                 wait_event (done.wait, done.done);
361                                 if (epdata->status == -ECONNRESET)
362                                         epdata->status = -EINTR;
363                         } else {
364                                 spin_unlock_irq (&epdata->dev->lock);
365
366                                 DBG (epdata->dev, "endpoint gone\n");
367                                 epdata->status = -ENODEV;
368                         }
369                 }
370                 return epdata->status;
371         }
372         return value;
373 }
374
375
376 /* handle a synchronous OUT bulk/intr/iso transfer */
377 static ssize_t
378 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
379 {
380         struct ep_data          *data = fd->private_data;
381         void                    *kbuf;
382         ssize_t                 value;
383
384         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
385                 return value;
386
387         /* halt any endpoint by doing a "wrong direction" i/o call */
388         if (usb_endpoint_dir_in(&data->desc)) {
389                 if (usb_endpoint_xfer_isoc(&data->desc))
390                         return -EINVAL;
391                 DBG (data->dev, "%s halt\n", data->name);
392                 spin_lock_irq (&data->dev->lock);
393                 if (likely (data->ep != NULL))
394                         usb_ep_set_halt (data->ep);
395                 spin_unlock_irq (&data->dev->lock);
396                 mutex_unlock(&data->lock);
397                 return -EBADMSG;
398         }
399
400         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
401
402         value = -ENOMEM;
403         kbuf = kmalloc (len, GFP_KERNEL);
404         if (unlikely (!kbuf))
405                 goto free1;
406
407         value = ep_io (data, kbuf, len);
408         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
409                 data->name, len, (int) value);
410         if (value >= 0 && copy_to_user (buf, kbuf, value))
411                 value = -EFAULT;
412
413 free1:
414         mutex_unlock(&data->lock);
415         kfree (kbuf);
416         return value;
417 }
418
419 /* handle a synchronous IN bulk/intr/iso transfer */
420 static ssize_t
421 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
422 {
423         struct ep_data          *data = fd->private_data;
424         void                    *kbuf;
425         ssize_t                 value;
426
427         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
428                 return value;
429
430         /* halt any endpoint by doing a "wrong direction" i/o call */
431         if (!usb_endpoint_dir_in(&data->desc)) {
432                 if (usb_endpoint_xfer_isoc(&data->desc))
433                         return -EINVAL;
434                 DBG (data->dev, "%s halt\n", data->name);
435                 spin_lock_irq (&data->dev->lock);
436                 if (likely (data->ep != NULL))
437                         usb_ep_set_halt (data->ep);
438                 spin_unlock_irq (&data->dev->lock);
439                 mutex_unlock(&data->lock);
440                 return -EBADMSG;
441         }
442
443         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
444
445         value = -ENOMEM;
446         kbuf = kmalloc (len, GFP_KERNEL);
447         if (!kbuf)
448                 goto free1;
449         if (copy_from_user (kbuf, buf, len)) {
450                 value = -EFAULT;
451                 goto free1;
452         }
453
454         value = ep_io (data, kbuf, len);
455         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
456                 data->name, len, (int) value);
457 free1:
458         mutex_unlock(&data->lock);
459         kfree (kbuf);
460         return value;
461 }
462
463 static int
464 ep_release (struct inode *inode, struct file *fd)
465 {
466         struct ep_data          *data = fd->private_data;
467         int value;
468
469         value = mutex_lock_interruptible(&data->lock);
470         if (value < 0)
471                 return value;
472
473         /* clean up if this can be reopened */
474         if (data->state != STATE_EP_UNBOUND) {
475                 data->state = STATE_EP_DISABLED;
476                 data->desc.bDescriptorType = 0;
477                 data->hs_desc.bDescriptorType = 0;
478                 usb_ep_disable(data->ep);
479         }
480         mutex_unlock(&data->lock);
481         put_ep (data);
482         return 0;
483 }
484
485 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
486 {
487         struct ep_data          *data = fd->private_data;
488         int                     status;
489
490         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
491                 return status;
492
493         spin_lock_irq (&data->dev->lock);
494         if (likely (data->ep != NULL)) {
495                 switch (code) {
496                 case GADGETFS_FIFO_STATUS:
497                         status = usb_ep_fifo_status (data->ep);
498                         break;
499                 case GADGETFS_FIFO_FLUSH:
500                         usb_ep_fifo_flush (data->ep);
501                         break;
502                 case GADGETFS_CLEAR_HALT:
503                         status = usb_ep_clear_halt (data->ep);
504                         break;
505                 default:
506                         status = -ENOTTY;
507                 }
508         } else
509                 status = -ENODEV;
510         spin_unlock_irq (&data->dev->lock);
511         mutex_unlock(&data->lock);
512         return status;
513 }
514
515 /*----------------------------------------------------------------------*/
516
517 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
518
519 struct kiocb_priv {
520         struct usb_request      *req;
521         struct ep_data          *epdata;
522         void                    *buf;
523         const struct iovec      *iv;
524         unsigned long           nr_segs;
525         unsigned                actual;
526 };
527
528 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
529 {
530         struct kiocb_priv       *priv = iocb->private;
531         struct ep_data          *epdata;
532         int                     value;
533
534         local_irq_disable();
535         epdata = priv->epdata;
536         // spin_lock(&epdata->dev->lock);
537         kiocbSetCancelled(iocb);
538         if (likely(epdata && epdata->ep && priv->req))
539                 value = usb_ep_dequeue (epdata->ep, priv->req);
540         else
541                 value = -EINVAL;
542         // spin_unlock(&epdata->dev->lock);
543         local_irq_enable();
544
545         aio_put_req(iocb);
546         return value;
547 }
548
549 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
550 {
551         struct kiocb_priv       *priv = iocb->private;
552         ssize_t                 len, total;
553         void                    *to_copy;
554         int                     i;
555
556         /* we "retry" to get the right mm context for this: */
557
558         /* copy stuff into user buffers */
559         total = priv->actual;
560         len = 0;
561         to_copy = priv->buf;
562         for (i=0; i < priv->nr_segs; i++) {
563                 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
564
565                 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
566                         if (len == 0)
567                                 len = -EFAULT;
568                         break;
569                 }
570
571                 total -= this;
572                 len += this;
573                 to_copy += this;
574                 if (total == 0)
575                         break;
576         }
577         kfree(priv->buf);
578         kfree(priv);
579         return len;
580 }
581
582 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
583 {
584         struct kiocb            *iocb = req->context;
585         struct kiocb_priv       *priv = iocb->private;
586         struct ep_data          *epdata = priv->epdata;
587
588         /* lock against disconnect (and ideally, cancel) */
589         spin_lock(&epdata->dev->lock);
590         priv->req = NULL;
591         priv->epdata = NULL;
592
593         /* if this was a write or a read returning no data then we
594          * don't need to copy anything to userspace, so we can
595          * complete the aio request immediately.
596          */
597         if (priv->iv == NULL || unlikely(req->actual == 0)) {
598                 kfree(req->buf);
599                 kfree(priv);
600                 iocb->private = NULL;
601                 /* aio_complete() reports bytes-transferred _and_ faults */
602                 aio_complete(iocb, req->actual ? req->actual : req->status,
603                                 req->status);
604         } else {
605                 /* retry() won't report both; so we hide some faults */
606                 if (unlikely(0 != req->status))
607                         DBG(epdata->dev, "%s fault %d len %d\n",
608                                 ep->name, req->status, req->actual);
609
610                 priv->buf = req->buf;
611                 priv->actual = req->actual;
612                 kick_iocb(iocb);
613         }
614         spin_unlock(&epdata->dev->lock);
615
616         usb_ep_free_request(ep, req);
617         put_ep(epdata);
618 }
619
620 static ssize_t
621 ep_aio_rwtail(
622         struct kiocb    *iocb,
623         char            *buf,
624         size_t          len,
625         struct ep_data  *epdata,
626         const struct iovec *iv,
627         unsigned long   nr_segs
628 )
629 {
630         struct kiocb_priv       *priv;
631         struct usb_request      *req;
632         ssize_t                 value;
633
634         priv = kmalloc(sizeof *priv, GFP_KERNEL);
635         if (!priv) {
636                 value = -ENOMEM;
637 fail:
638                 kfree(buf);
639                 return value;
640         }
641         iocb->private = priv;
642         priv->iv = iv;
643         priv->nr_segs = nr_segs;
644
645         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
646         if (unlikely(value < 0)) {
647                 kfree(priv);
648                 goto fail;
649         }
650
651         iocb->ki_cancel = ep_aio_cancel;
652         get_ep(epdata);
653         priv->epdata = epdata;
654         priv->actual = 0;
655
656         /* each kiocb is coupled to one usb_request, but we can't
657          * allocate or submit those if the host disconnected.
658          */
659         spin_lock_irq(&epdata->dev->lock);
660         if (likely(epdata->ep)) {
661                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
662                 if (likely(req)) {
663                         priv->req = req;
664                         req->buf = buf;
665                         req->length = len;
666                         req->complete = ep_aio_complete;
667                         req->context = iocb;
668                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
669                         if (unlikely(0 != value))
670                                 usb_ep_free_request(epdata->ep, req);
671                 } else
672                         value = -EAGAIN;
673         } else
674                 value = -ENODEV;
675         spin_unlock_irq(&epdata->dev->lock);
676
677         mutex_unlock(&epdata->lock);
678
679         if (unlikely(value)) {
680                 kfree(priv);
681                 put_ep(epdata);
682         } else
683                 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
684         return value;
685 }
686
687 static ssize_t
688 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
689                 unsigned long nr_segs, loff_t o)
690 {
691         struct ep_data          *epdata = iocb->ki_filp->private_data;
692         char                    *buf;
693
694         if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
695                 return -EINVAL;
696
697         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
698         if (unlikely(!buf))
699                 return -ENOMEM;
700
701         iocb->ki_retry = ep_aio_read_retry;
702         return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
703 }
704
705 static ssize_t
706 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
707                 unsigned long nr_segs, loff_t o)
708 {
709         struct ep_data          *epdata = iocb->ki_filp->private_data;
710         char                    *buf;
711         size_t                  len = 0;
712         int                     i = 0;
713
714         if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
715                 return -EINVAL;
716
717         buf = kmalloc(iocb->ki_left, GFP_KERNEL);
718         if (unlikely(!buf))
719                 return -ENOMEM;
720
721         for (i=0; i < nr_segs; i++) {
722                 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
723                                 iov[i].iov_len) != 0)) {
724                         kfree(buf);
725                         return -EFAULT;
726                 }
727                 len += iov[i].iov_len;
728         }
729         return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
730 }
731
732 /*----------------------------------------------------------------------*/
733
734 /* used after endpoint configuration */
735 static const struct file_operations ep_io_operations = {
736         .owner =        THIS_MODULE,
737         .llseek =       no_llseek,
738
739         .read =         ep_read,
740         .write =        ep_write,
741         .unlocked_ioctl = ep_ioctl,
742         .release =      ep_release,
743
744         .aio_read =     ep_aio_read,
745         .aio_write =    ep_aio_write,
746 };
747
748 /* ENDPOINT INITIALIZATION
749  *
750  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
751  *     status = write (fd, descriptors, sizeof descriptors)
752  *
753  * That write establishes the endpoint configuration, configuring
754  * the controller to process bulk, interrupt, or isochronous transfers
755  * at the right maxpacket size, and so on.
756  *
757  * The descriptors are message type 1, identified by a host order u32
758  * at the beginning of what's written.  Descriptor order is: full/low
759  * speed descriptor, then optional high speed descriptor.
760  */
761 static ssize_t
762 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
763 {
764         struct ep_data          *data = fd->private_data;
765         struct usb_ep           *ep;
766         u32                     tag;
767         int                     value, length = len;
768
769         value = mutex_lock_interruptible(&data->lock);
770         if (value < 0)
771                 return value;
772
773         if (data->state != STATE_EP_READY) {
774                 value = -EL2HLT;
775                 goto fail;
776         }
777
778         value = len;
779         if (len < USB_DT_ENDPOINT_SIZE + 4)
780                 goto fail0;
781
782         /* we might need to change message format someday */
783         if (copy_from_user (&tag, buf, 4)) {
784                 goto fail1;
785         }
786         if (tag != 1) {
787                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
788                 goto fail0;
789         }
790         buf += 4;
791         len -= 4;
792
793         /* NOTE:  audio endpoint extensions not accepted here;
794          * just don't include the extra bytes.
795          */
796
797         /* full/low speed descriptor, then high speed */
798         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
799                 goto fail1;
800         }
801         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
802                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
803                 goto fail0;
804         if (len != USB_DT_ENDPOINT_SIZE) {
805                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
806                         goto fail0;
807                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
808                                         USB_DT_ENDPOINT_SIZE)) {
809                         goto fail1;
810                 }
811                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
812                                 || data->hs_desc.bDescriptorType
813                                         != USB_DT_ENDPOINT) {
814                         DBG(data->dev, "config %s, bad hs length or type\n",
815                                         data->name);
816                         goto fail0;
817                 }
818         }
819
820         spin_lock_irq (&data->dev->lock);
821         if (data->dev->state == STATE_DEV_UNBOUND) {
822                 value = -ENOENT;
823                 goto gone;
824         } else if ((ep = data->ep) == NULL) {
825                 value = -ENODEV;
826                 goto gone;
827         }
828         switch (data->dev->gadget->speed) {
829         case USB_SPEED_LOW:
830         case USB_SPEED_FULL:
831                 value = usb_ep_enable (ep, &data->desc);
832                 if (value == 0)
833                         data->state = STATE_EP_ENABLED;
834                 break;
835 #ifdef  CONFIG_USB_GADGET_DUALSPEED
836         case USB_SPEED_HIGH:
837                 /* fails if caller didn't provide that descriptor... */
838                 value = usb_ep_enable (ep, &data->hs_desc);
839                 if (value == 0)
840                         data->state = STATE_EP_ENABLED;
841                 break;
842 #endif
843         default:
844                 DBG(data->dev, "unconnected, %s init abandoned\n",
845                                 data->name);
846                 value = -EINVAL;
847         }
848         if (value == 0) {
849                 fd->f_op = &ep_io_operations;
850                 value = length;
851         }
852 gone:
853         spin_unlock_irq (&data->dev->lock);
854         if (value < 0) {
855 fail:
856                 data->desc.bDescriptorType = 0;
857                 data->hs_desc.bDescriptorType = 0;
858         }
859         mutex_unlock(&data->lock);
860         return value;
861 fail0:
862         value = -EINVAL;
863         goto fail;
864 fail1:
865         value = -EFAULT;
866         goto fail;
867 }
868
869 static int
870 ep_open (struct inode *inode, struct file *fd)
871 {
872         struct ep_data          *data = inode->i_private;
873         int                     value = -EBUSY;
874
875         if (mutex_lock_interruptible(&data->lock) != 0)
876                 return -EINTR;
877         spin_lock_irq (&data->dev->lock);
878         if (data->dev->state == STATE_DEV_UNBOUND)
879                 value = -ENOENT;
880         else if (data->state == STATE_EP_DISABLED) {
881                 value = 0;
882                 data->state = STATE_EP_READY;
883                 get_ep (data);
884                 fd->private_data = data;
885                 VDEBUG (data->dev, "%s ready\n", data->name);
886         } else
887                 DBG (data->dev, "%s state %d\n",
888                         data->name, data->state);
889         spin_unlock_irq (&data->dev->lock);
890         mutex_unlock(&data->lock);
891         return value;
892 }
893
894 /* used before endpoint configuration */
895 static const struct file_operations ep_config_operations = {
896         .owner =        THIS_MODULE,
897         .llseek =       no_llseek,
898
899         .open =         ep_open,
900         .write =        ep_config,
901         .release =      ep_release,
902 };
903
904 /*----------------------------------------------------------------------*/
905
906 /* EP0 IMPLEMENTATION can be partly in userspace.
907  *
908  * Drivers that use this facility receive various events, including
909  * control requests the kernel doesn't handle.  Drivers that don't
910  * use this facility may be too simple-minded for real applications.
911  */
912
913 static inline void ep0_readable (struct dev_data *dev)
914 {
915         wake_up (&dev->wait);
916         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
917 }
918
919 static void clean_req (struct usb_ep *ep, struct usb_request *req)
920 {
921         struct dev_data         *dev = ep->driver_data;
922
923         if (req->buf != dev->rbuf) {
924                 kfree(req->buf);
925                 req->buf = dev->rbuf;
926                 req->dma = DMA_ADDR_INVALID;
927         }
928         req->complete = epio_complete;
929         dev->setup_out_ready = 0;
930 }
931
932 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
933 {
934         struct dev_data         *dev = ep->driver_data;
935         unsigned long           flags;
936         int                     free = 1;
937
938         /* for control OUT, data must still get to userspace */
939         spin_lock_irqsave(&dev->lock, flags);
940         if (!dev->setup_in) {
941                 dev->setup_out_error = (req->status != 0);
942                 if (!dev->setup_out_error)
943                         free = 0;
944                 dev->setup_out_ready = 1;
945                 ep0_readable (dev);
946         }
947
948         /* clean up as appropriate */
949         if (free && req->buf != &dev->rbuf)
950                 clean_req (ep, req);
951         req->complete = epio_complete;
952         spin_unlock_irqrestore(&dev->lock, flags);
953 }
954
955 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
956 {
957         struct dev_data *dev = ep->driver_data;
958
959         if (dev->setup_out_ready) {
960                 DBG (dev, "ep0 request busy!\n");
961                 return -EBUSY;
962         }
963         if (len > sizeof (dev->rbuf))
964                 req->buf = kmalloc(len, GFP_ATOMIC);
965         if (req->buf == NULL) {
966                 req->buf = dev->rbuf;
967                 return -ENOMEM;
968         }
969         req->complete = ep0_complete;
970         req->length = len;
971         req->zero = 0;
972         return 0;
973 }
974
975 static ssize_t
976 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
977 {
978         struct dev_data                 *dev = fd->private_data;
979         ssize_t                         retval;
980         enum ep0_state                  state;
981
982         spin_lock_irq (&dev->lock);
983
984         /* report fd mode change before acting on it */
985         if (dev->setup_abort) {
986                 dev->setup_abort = 0;
987                 retval = -EIDRM;
988                 goto done;
989         }
990
991         /* control DATA stage */
992         if ((state = dev->state) == STATE_DEV_SETUP) {
993
994                 if (dev->setup_in) {            /* stall IN */
995                         VDEBUG(dev, "ep0in stall\n");
996                         (void) usb_ep_set_halt (dev->gadget->ep0);
997                         retval = -EL2HLT;
998                         dev->state = STATE_DEV_CONNECTED;
999
1000                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
1001                         struct usb_ep           *ep = dev->gadget->ep0;
1002                         struct usb_request      *req = dev->req;
1003
1004                         if ((retval = setup_req (ep, req, 0)) == 0)
1005                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1006                         dev->state = STATE_DEV_CONNECTED;
1007
1008                         /* assume that was SET_CONFIGURATION */
1009                         if (dev->current_config) {
1010                                 unsigned power;
1011
1012                                 if (gadget_is_dualspeed(dev->gadget)
1013                                                 && (dev->gadget->speed
1014                                                         == USB_SPEED_HIGH))
1015                                         power = dev->hs_config->bMaxPower;
1016                                 else
1017                                         power = dev->config->bMaxPower;
1018                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1019                         }
1020
1021                 } else {                        /* collect OUT data */
1022                         if ((fd->f_flags & O_NONBLOCK) != 0
1023                                         && !dev->setup_out_ready) {
1024                                 retval = -EAGAIN;
1025                                 goto done;
1026                         }
1027                         spin_unlock_irq (&dev->lock);
1028                         retval = wait_event_interruptible (dev->wait,
1029                                         dev->setup_out_ready != 0);
1030
1031                         /* FIXME state could change from under us */
1032                         spin_lock_irq (&dev->lock);
1033                         if (retval)
1034                                 goto done;
1035
1036                         if (dev->state != STATE_DEV_SETUP) {
1037                                 retval = -ECANCELED;
1038                                 goto done;
1039                         }
1040                         dev->state = STATE_DEV_CONNECTED;
1041
1042                         if (dev->setup_out_error)
1043                                 retval = -EIO;
1044                         else {
1045                                 len = min (len, (size_t)dev->req->actual);
1046 // FIXME don't call this with the spinlock held ...
1047                                 if (copy_to_user (buf, dev->req->buf, len))
1048                                         retval = -EFAULT;
1049                                 clean_req (dev->gadget->ep0, dev->req);
1050                                 /* NOTE userspace can't yet choose to stall */
1051                         }
1052                 }
1053                 goto done;
1054         }
1055
1056         /* else normal: return event data */
1057         if (len < sizeof dev->event [0]) {
1058                 retval = -EINVAL;
1059                 goto done;
1060         }
1061         len -= len % sizeof (struct usb_gadgetfs_event);
1062         dev->usermode_setup = 1;
1063
1064 scan:
1065         /* return queued events right away */
1066         if (dev->ev_next != 0) {
1067                 unsigned                i, n;
1068
1069                 n = len / sizeof (struct usb_gadgetfs_event);
1070                 if (dev->ev_next < n)
1071                         n = dev->ev_next;
1072
1073                 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1074                 for (i = 0; i < n; i++) {
1075                         if (dev->event [i].type == GADGETFS_SETUP) {
1076                                 dev->state = STATE_DEV_SETUP;
1077                                 n = i + 1;
1078                                 break;
1079                         }
1080                 }
1081                 spin_unlock_irq (&dev->lock);
1082                 len = n * sizeof (struct usb_gadgetfs_event);
1083                 if (copy_to_user (buf, &dev->event, len))
1084                         retval = -EFAULT;
1085                 else
1086                         retval = len;
1087                 if (len > 0) {
1088                         /* NOTE this doesn't guard against broken drivers;
1089                          * concurrent ep0 readers may lose events.
1090                          */
1091                         spin_lock_irq (&dev->lock);
1092                         if (dev->ev_next > n) {
1093                                 memmove(&dev->event[0], &dev->event[n],
1094                                         sizeof (struct usb_gadgetfs_event)
1095                                                 * (dev->ev_next - n));
1096                         }
1097                         dev->ev_next -= n;
1098                         spin_unlock_irq (&dev->lock);
1099                 }
1100                 return retval;
1101         }
1102         if (fd->f_flags & O_NONBLOCK) {
1103                 retval = -EAGAIN;
1104                 goto done;
1105         }
1106
1107         switch (state) {
1108         default:
1109                 DBG (dev, "fail %s, state %d\n", __func__, state);
1110                 retval = -ESRCH;
1111                 break;
1112         case STATE_DEV_UNCONNECTED:
1113         case STATE_DEV_CONNECTED:
1114                 spin_unlock_irq (&dev->lock);
1115                 DBG (dev, "%s wait\n", __func__);
1116
1117                 /* wait for events */
1118                 retval = wait_event_interruptible (dev->wait,
1119                                 dev->ev_next != 0);
1120                 if (retval < 0)
1121                         return retval;
1122                 spin_lock_irq (&dev->lock);
1123                 goto scan;
1124         }
1125
1126 done:
1127         spin_unlock_irq (&dev->lock);
1128         return retval;
1129 }
1130
1131 static struct usb_gadgetfs_event *
1132 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1133 {
1134         struct usb_gadgetfs_event       *event;
1135         unsigned                        i;
1136
1137         switch (type) {
1138         /* these events purge the queue */
1139         case GADGETFS_DISCONNECT:
1140                 if (dev->state == STATE_DEV_SETUP)
1141                         dev->setup_abort = 1;
1142                 // FALL THROUGH
1143         case GADGETFS_CONNECT:
1144                 dev->ev_next = 0;
1145                 break;
1146         case GADGETFS_SETUP:            /* previous request timed out */
1147         case GADGETFS_SUSPEND:          /* same effect */
1148                 /* these events can't be repeated */
1149                 for (i = 0; i != dev->ev_next; i++) {
1150                         if (dev->event [i].type != type)
1151                                 continue;
1152                         DBG(dev, "discard old event[%d] %d\n", i, type);
1153                         dev->ev_next--;
1154                         if (i == dev->ev_next)
1155                                 break;
1156                         /* indices start at zero, for simplicity */
1157                         memmove (&dev->event [i], &dev->event [i + 1],
1158                                 sizeof (struct usb_gadgetfs_event)
1159                                         * (dev->ev_next - i));
1160                 }
1161                 break;
1162         default:
1163                 BUG ();
1164         }
1165         VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1166         event = &dev->event [dev->ev_next++];
1167         BUG_ON (dev->ev_next > N_EVENT);
1168         memset (event, 0, sizeof *event);
1169         event->type = type;
1170         return event;
1171 }
1172
1173 static ssize_t
1174 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1175 {
1176         struct dev_data         *dev = fd->private_data;
1177         ssize_t                 retval = -ESRCH;
1178
1179         spin_lock_irq (&dev->lock);
1180
1181         /* report fd mode change before acting on it */
1182         if (dev->setup_abort) {
1183                 dev->setup_abort = 0;
1184                 retval = -EIDRM;
1185
1186         /* data and/or status stage for control request */
1187         } else if (dev->state == STATE_DEV_SETUP) {
1188
1189                 /* IN DATA+STATUS caller makes len <= wLength */
1190                 if (dev->setup_in) {
1191                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1192                         if (retval == 0) {
1193                                 dev->state = STATE_DEV_CONNECTED;
1194                                 spin_unlock_irq (&dev->lock);
1195                                 if (copy_from_user (dev->req->buf, buf, len))
1196                                         retval = -EFAULT;
1197                                 else {
1198                                         if (len < dev->setup_wLength)
1199                                                 dev->req->zero = 1;
1200                                         retval = usb_ep_queue (
1201                                                 dev->gadget->ep0, dev->req,
1202                                                 GFP_KERNEL);
1203                                 }
1204                                 if (retval < 0) {
1205                                         spin_lock_irq (&dev->lock);
1206                                         clean_req (dev->gadget->ep0, dev->req);
1207                                         spin_unlock_irq (&dev->lock);
1208                                 } else
1209                                         retval = len;
1210
1211                                 return retval;
1212                         }
1213
1214                 /* can stall some OUT transfers */
1215                 } else if (dev->setup_can_stall) {
1216                         VDEBUG(dev, "ep0out stall\n");
1217                         (void) usb_ep_set_halt (dev->gadget->ep0);
1218                         retval = -EL2HLT;
1219                         dev->state = STATE_DEV_CONNECTED;
1220                 } else {
1221                         DBG(dev, "bogus ep0out stall!\n");
1222                 }
1223         } else
1224                 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1225
1226         spin_unlock_irq (&dev->lock);
1227         return retval;
1228 }
1229
1230 static int
1231 ep0_fasync (int f, struct file *fd, int on)
1232 {
1233         struct dev_data         *dev = fd->private_data;
1234         // caller must F_SETOWN before signal delivery happens
1235         VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1236         return fasync_helper (f, fd, on, &dev->fasync);
1237 }
1238
1239 static struct usb_gadget_driver gadgetfs_driver;
1240
1241 static int
1242 dev_release (struct inode *inode, struct file *fd)
1243 {
1244         struct dev_data         *dev = fd->private_data;
1245
1246         /* closing ep0 === shutdown all */
1247
1248         usb_gadget_unregister_driver (&gadgetfs_driver);
1249
1250         /* at this point "good" hardware has disconnected the
1251          * device from USB; the host won't see it any more.
1252          * alternatively, all host requests will time out.
1253          */
1254
1255         kfree (dev->buf);
1256         dev->buf = NULL;
1257         put_dev (dev);
1258
1259         /* other endpoints were all decoupled from this device */
1260         spin_lock_irq(&dev->lock);
1261         dev->state = STATE_DEV_DISABLED;
1262         spin_unlock_irq(&dev->lock);
1263         return 0;
1264 }
1265
1266 static unsigned int
1267 ep0_poll (struct file *fd, poll_table *wait)
1268 {
1269        struct dev_data         *dev = fd->private_data;
1270        int                     mask = 0;
1271
1272        poll_wait(fd, &dev->wait, wait);
1273
1274        spin_lock_irq (&dev->lock);
1275
1276        /* report fd mode change before acting on it */
1277        if (dev->setup_abort) {
1278                dev->setup_abort = 0;
1279                mask = POLLHUP;
1280                goto out;
1281        }
1282
1283        if (dev->state == STATE_DEV_SETUP) {
1284                if (dev->setup_in || dev->setup_can_stall)
1285                        mask = POLLOUT;
1286        } else {
1287                if (dev->ev_next != 0)
1288                        mask = POLLIN;
1289        }
1290 out:
1291        spin_unlock_irq(&dev->lock);
1292        return mask;
1293 }
1294
1295 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1296 {
1297         struct dev_data         *dev = fd->private_data;
1298         struct usb_gadget       *gadget = dev->gadget;
1299         long ret = -ENOTTY;
1300
1301         if (gadget->ops->ioctl)
1302                 ret = gadget->ops->ioctl (gadget, code, value);
1303
1304         return ret;
1305 }
1306
1307 /* used after device configuration */
1308 static const struct file_operations ep0_io_operations = {
1309         .owner =        THIS_MODULE,
1310         .llseek =       no_llseek,
1311
1312         .read =         ep0_read,
1313         .write =        ep0_write,
1314         .fasync =       ep0_fasync,
1315         .poll =         ep0_poll,
1316         .unlocked_ioctl =       dev_ioctl,
1317         .release =      dev_release,
1318 };
1319
1320 /*----------------------------------------------------------------------*/
1321
1322 /* The in-kernel gadget driver handles most ep0 issues, in particular
1323  * enumerating the single configuration (as provided from user space).
1324  *
1325  * Unrecognized ep0 requests may be handled in user space.
1326  */
1327
1328 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1329 static void make_qualifier (struct dev_data *dev)
1330 {
1331         struct usb_qualifier_descriptor         qual;
1332         struct usb_device_descriptor            *desc;
1333
1334         qual.bLength = sizeof qual;
1335         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1336         qual.bcdUSB = cpu_to_le16 (0x0200);
1337
1338         desc = dev->dev;
1339         qual.bDeviceClass = desc->bDeviceClass;
1340         qual.bDeviceSubClass = desc->bDeviceSubClass;
1341         qual.bDeviceProtocol = desc->bDeviceProtocol;
1342
1343         /* assumes ep0 uses the same value for both speeds ... */
1344         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1345
1346         qual.bNumConfigurations = 1;
1347         qual.bRESERVED = 0;
1348
1349         memcpy (dev->rbuf, &qual, sizeof qual);
1350 }
1351 #endif
1352
1353 static int
1354 config_buf (struct dev_data *dev, u8 type, unsigned index)
1355 {
1356         int             len;
1357         int             hs = 0;
1358
1359         /* only one configuration */
1360         if (index > 0)
1361                 return -EINVAL;
1362
1363         if (gadget_is_dualspeed(dev->gadget)) {
1364                 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1365                 if (type == USB_DT_OTHER_SPEED_CONFIG)
1366                         hs = !hs;
1367         }
1368         if (hs) {
1369                 dev->req->buf = dev->hs_config;
1370                 len = le16_to_cpu(dev->hs_config->wTotalLength);
1371         } else {
1372                 dev->req->buf = dev->config;
1373                 len = le16_to_cpu(dev->config->wTotalLength);
1374         }
1375         ((u8 *)dev->req->buf) [1] = type;
1376         return len;
1377 }
1378
1379 static int
1380 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1381 {
1382         struct dev_data                 *dev = get_gadget_data (gadget);
1383         struct usb_request              *req = dev->req;
1384         int                             value = -EOPNOTSUPP;
1385         struct usb_gadgetfs_event       *event;
1386         u16                             w_value = le16_to_cpu(ctrl->wValue);
1387         u16                             w_length = le16_to_cpu(ctrl->wLength);
1388
1389         spin_lock (&dev->lock);
1390         dev->setup_abort = 0;
1391         if (dev->state == STATE_DEV_UNCONNECTED) {
1392                 if (gadget_is_dualspeed(gadget)
1393                                 && gadget->speed == USB_SPEED_HIGH
1394                                 && dev->hs_config == NULL) {
1395                         spin_unlock(&dev->lock);
1396                         ERROR (dev, "no high speed config??\n");
1397                         return -EINVAL;
1398                 }
1399
1400                 dev->state = STATE_DEV_CONNECTED;
1401                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1402
1403                 INFO (dev, "connected\n");
1404                 event = next_event (dev, GADGETFS_CONNECT);
1405                 event->u.speed = gadget->speed;
1406                 ep0_readable (dev);
1407
1408         /* host may have given up waiting for response.  we can miss control
1409          * requests handled lower down (device/endpoint status and features);
1410          * then ep0_{read,write} will report the wrong status. controller
1411          * driver will have aborted pending i/o.
1412          */
1413         } else if (dev->state == STATE_DEV_SETUP)
1414                 dev->setup_abort = 1;
1415
1416         req->buf = dev->rbuf;
1417         req->dma = DMA_ADDR_INVALID;
1418         req->context = NULL;
1419         value = -EOPNOTSUPP;
1420         switch (ctrl->bRequest) {
1421
1422         case USB_REQ_GET_DESCRIPTOR:
1423                 if (ctrl->bRequestType != USB_DIR_IN)
1424                         goto unrecognized;
1425                 switch (w_value >> 8) {
1426
1427                 case USB_DT_DEVICE:
1428                         value = min (w_length, (u16) sizeof *dev->dev);
1429                         req->buf = dev->dev;
1430                         break;
1431 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1432                 case USB_DT_DEVICE_QUALIFIER:
1433                         if (!dev->hs_config)
1434                                 break;
1435                         value = min (w_length, (u16)
1436                                 sizeof (struct usb_qualifier_descriptor));
1437                         make_qualifier (dev);
1438                         break;
1439                 case USB_DT_OTHER_SPEED_CONFIG:
1440                         // FALLTHROUGH
1441 #endif
1442                 case USB_DT_CONFIG:
1443                         value = config_buf (dev,
1444                                         w_value >> 8,
1445                                         w_value & 0xff);
1446                         if (value >= 0)
1447                                 value = min (w_length, (u16) value);
1448                         break;
1449                 case USB_DT_STRING:
1450                         goto unrecognized;
1451
1452                 default:                // all others are errors
1453                         break;
1454                 }
1455                 break;
1456
1457         /* currently one config, two speeds */
1458         case USB_REQ_SET_CONFIGURATION:
1459                 if (ctrl->bRequestType != 0)
1460                         goto unrecognized;
1461                 if (0 == (u8) w_value) {
1462                         value = 0;
1463                         dev->current_config = 0;
1464                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1465                         // user mode expected to disable endpoints
1466                 } else {
1467                         u8      config, power;
1468
1469                         if (gadget_is_dualspeed(gadget)
1470                                         && gadget->speed == USB_SPEED_HIGH) {
1471                                 config = dev->hs_config->bConfigurationValue;
1472                                 power = dev->hs_config->bMaxPower;
1473                         } else {
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_GADGET_PXA25X
1504         /* PXA automagically handles this request too */
1505         case USB_REQ_GET_CONFIGURATION:
1506                 if (ctrl->bRequestType != 0x80)
1507                         goto unrecognized;
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", __func__, 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                 mutex_init(&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", __func__);
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", __func__);
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", __func__);
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                 pr_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         .unbind         = gadgetfs_unbind,
1778         .setup          = gadgetfs_setup,
1779         .disconnect     = gadgetfs_disconnect,
1780         .suspend        = gadgetfs_suspend,
1781
1782         .driver = {
1783                 .name           = (char *) shortname,
1784         },
1785 };
1786
1787 /*----------------------------------------------------------------------*/
1788
1789 static void gadgetfs_nop(struct usb_gadget *arg) { }
1790
1791 static int gadgetfs_probe (struct usb_gadget *gadget)
1792 {
1793         CHIP = gadget->name;
1794         return -EISNAM;
1795 }
1796
1797 static struct usb_gadget_driver probe_driver = {
1798         .speed          = USB_SPEED_HIGH,
1799         .unbind         = gadgetfs_nop,
1800         .setup          = (void *)gadgetfs_nop,
1801         .disconnect     = gadgetfs_nop,
1802         .driver = {
1803                 .name           = "nop",
1804         },
1805 };
1806
1807
1808 /* DEVICE INITIALIZATION
1809  *
1810  *     fd = open ("/dev/gadget/$CHIP", O_RDWR)
1811  *     status = write (fd, descriptors, sizeof descriptors)
1812  *
1813  * That write establishes the device configuration, so the kernel can
1814  * bind to the controller ... guaranteeing it can handle enumeration
1815  * at all necessary speeds.  Descriptor order is:
1816  *
1817  * . message tag (u32, host order) ... for now, must be zero; it
1818  *      would change to support features like multi-config devices
1819  * . full/low speed config ... all wTotalLength bytes (with interface,
1820  *      class, altsetting, endpoint, and other descriptors)
1821  * . high speed config ... all descriptors, for high speed operation;
1822  *      this one's optional except for high-speed hardware
1823  * . device descriptor
1824  *
1825  * Endpoints are not yet enabled. Drivers must wait until device
1826  * configuration and interface altsetting changes create
1827  * the need to configure (or unconfigure) them.
1828  *
1829  * After initialization, the device stays active for as long as that
1830  * $CHIP file is open.  Events must then be read from that descriptor,
1831  * such as configuration notifications.
1832  */
1833
1834 static int is_valid_config (struct usb_config_descriptor *config)
1835 {
1836         return config->bDescriptorType == USB_DT_CONFIG
1837                 && config->bLength == USB_DT_CONFIG_SIZE
1838                 && config->bConfigurationValue != 0
1839                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1840                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1841         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1842         /* FIXME check lengths: walk to end */
1843 }
1844
1845 static ssize_t
1846 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1847 {
1848         struct dev_data         *dev = fd->private_data;
1849         ssize_t                 value = len, length = len;
1850         unsigned                total;
1851         u32                     tag;
1852         char                    *kbuf;
1853
1854         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1855                 return -EINVAL;
1856
1857         /* we might need to change message format someday */
1858         if (copy_from_user (&tag, buf, 4))
1859                 return -EFAULT;
1860         if (tag != 0)
1861                 return -EINVAL;
1862         buf += 4;
1863         length -= 4;
1864
1865         kbuf = memdup_user(buf, length);
1866         if (IS_ERR(kbuf))
1867                 return PTR_ERR(kbuf);
1868
1869         spin_lock_irq (&dev->lock);
1870         value = -EINVAL;
1871         if (dev->buf)
1872                 goto fail;
1873         dev->buf = kbuf;
1874
1875         /* full or low speed config */
1876         dev->config = (void *) kbuf;
1877         total = le16_to_cpu(dev->config->wTotalLength);
1878         if (!is_valid_config (dev->config) || total >= length)
1879                 goto fail;
1880         kbuf += total;
1881         length -= total;
1882
1883         /* optional high speed config */
1884         if (kbuf [1] == USB_DT_CONFIG) {
1885                 dev->hs_config = (void *) kbuf;
1886                 total = le16_to_cpu(dev->hs_config->wTotalLength);
1887                 if (!is_valid_config (dev->hs_config) || total >= length)
1888                         goto fail;
1889                 kbuf += total;
1890                 length -= total;
1891         }
1892
1893         /* could support multiple configs, using another encoding! */
1894
1895         /* device descriptor (tweaked for paranoia) */
1896         if (length != USB_DT_DEVICE_SIZE)
1897                 goto fail;
1898         dev->dev = (void *)kbuf;
1899         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1900                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1901                         || dev->dev->bNumConfigurations != 1)
1902                 goto fail;
1903         dev->dev->bNumConfigurations = 1;
1904         dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1905
1906         /* triggers gadgetfs_bind(); then we can enumerate. */
1907         spin_unlock_irq (&dev->lock);
1908         value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1909         if (value != 0) {
1910                 kfree (dev->buf);
1911                 dev->buf = NULL;
1912         } else {
1913                 /* at this point "good" hardware has for the first time
1914                  * let the USB the host see us.  alternatively, if users
1915                  * unplug/replug that will clear all the error state.
1916                  *
1917                  * note:  everything running before here was guaranteed
1918                  * to choke driver model style diagnostics.  from here
1919                  * on, they can work ... except in cleanup paths that
1920                  * kick in after the ep0 descriptor is closed.
1921                  */
1922                 fd->f_op = &ep0_io_operations;
1923                 value = len;
1924         }
1925         return value;
1926
1927 fail:
1928         spin_unlock_irq (&dev->lock);
1929         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1930         kfree (dev->buf);
1931         dev->buf = NULL;
1932         return value;
1933 }
1934
1935 static int
1936 dev_open (struct inode *inode, struct file *fd)
1937 {
1938         struct dev_data         *dev = inode->i_private;
1939         int                     value = -EBUSY;
1940
1941         spin_lock_irq(&dev->lock);
1942         if (dev->state == STATE_DEV_DISABLED) {
1943                 dev->ev_next = 0;
1944                 dev->state = STATE_DEV_OPENED;
1945                 fd->private_data = dev;
1946                 get_dev (dev);
1947                 value = 0;
1948         }
1949         spin_unlock_irq(&dev->lock);
1950         return value;
1951 }
1952
1953 static const struct file_operations dev_init_operations = {
1954         .owner =        THIS_MODULE,
1955         .llseek =       no_llseek,
1956
1957         .open =         dev_open,
1958         .write =        dev_config,
1959         .fasync =       ep0_fasync,
1960         .unlocked_ioctl = dev_ioctl,
1961         .release =      dev_release,
1962 };
1963
1964 /*----------------------------------------------------------------------*/
1965
1966 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1967  *
1968  * Mounting the filesystem creates a controller file, used first for
1969  * device configuration then later for event monitoring.
1970  */
1971
1972
1973 /* FIXME PAM etc could set this security policy without mount options
1974  * if epfiles inherited ownership and permissons from ep0 ...
1975  */
1976
1977 static unsigned default_uid;
1978 static unsigned default_gid;
1979 static unsigned default_perm = S_IRUSR | S_IWUSR;
1980
1981 module_param (default_uid, uint, 0644);
1982 module_param (default_gid, uint, 0644);
1983 module_param (default_perm, uint, 0644);
1984
1985
1986 static struct inode *
1987 gadgetfs_make_inode (struct super_block *sb,
1988                 void *data, const struct file_operations *fops,
1989                 int mode)
1990 {
1991         struct inode *inode = new_inode (sb);
1992
1993         if (inode) {
1994                 inode->i_ino = get_next_ino();
1995                 inode->i_mode = mode;
1996                 inode->i_uid = default_uid;
1997                 inode->i_gid = default_gid;
1998                 inode->i_atime = inode->i_mtime = inode->i_ctime
1999                                 = CURRENT_TIME;
2000                 inode->i_private = data;
2001                 inode->i_fop = fops;
2002         }
2003         return inode;
2004 }
2005
2006 /* creates in fs root directory, so non-renamable and non-linkable.
2007  * so inode and dentry are paired, until device reconfig.
2008  */
2009 static struct inode *
2010 gadgetfs_create_file (struct super_block *sb, char const *name,
2011                 void *data, const struct file_operations *fops,
2012                 struct dentry **dentry_p)
2013 {
2014         struct dentry   *dentry;
2015         struct inode    *inode;
2016
2017         dentry = d_alloc_name(sb->s_root, name);
2018         if (!dentry)
2019                 return NULL;
2020
2021         inode = gadgetfs_make_inode (sb, data, fops,
2022                         S_IFREG | (default_perm & S_IRWXUGO));
2023         if (!inode) {
2024                 dput(dentry);
2025                 return NULL;
2026         }
2027         d_add (dentry, inode);
2028         *dentry_p = dentry;
2029         return inode;
2030 }
2031
2032 static const struct super_operations gadget_fs_operations = {
2033         .statfs =       simple_statfs,
2034         .drop_inode =   generic_delete_inode,
2035 };
2036
2037 static int
2038 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2039 {
2040         struct inode    *inode;
2041         struct dentry   *d;
2042         struct dev_data *dev;
2043
2044         if (the_device)
2045                 return -ESRCH;
2046
2047         /* fake probe to determine $CHIP */
2048         (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2049         if (!CHIP)
2050                 return -ENODEV;
2051
2052         /* superblock */
2053         sb->s_blocksize = PAGE_CACHE_SIZE;
2054         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2055         sb->s_magic = GADGETFS_MAGIC;
2056         sb->s_op = &gadget_fs_operations;
2057         sb->s_time_gran = 1;
2058
2059         /* root inode */
2060         inode = gadgetfs_make_inode (sb,
2061                         NULL, &simple_dir_operations,
2062                         S_IFDIR | S_IRUGO | S_IXUGO);
2063         if (!inode)
2064                 goto enomem0;
2065         inode->i_op = &simple_dir_inode_operations;
2066         if (!(d = d_alloc_root (inode)))
2067                 goto enomem1;
2068         sb->s_root = d;
2069
2070         /* the ep0 file is named after the controller we expect;
2071          * user mode code can use it for sanity checks, like we do.
2072          */
2073         dev = dev_new ();
2074         if (!dev)
2075                 goto enomem2;
2076
2077         dev->sb = sb;
2078         if (!gadgetfs_create_file (sb, CHIP,
2079                                 dev, &dev_init_operations,
2080                                 &dev->dentry))
2081                 goto enomem3;
2082
2083         /* other endpoint files are available after hardware setup,
2084          * from binding to a controller.
2085          */
2086         the_device = dev;
2087         return 0;
2088
2089 enomem3:
2090         put_dev (dev);
2091 enomem2:
2092         dput (d);
2093 enomem1:
2094         iput (inode);
2095 enomem0:
2096         return -ENOMEM;
2097 }
2098
2099 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2100 static struct dentry *
2101 gadgetfs_mount (struct file_system_type *t, int flags,
2102                 const char *path, void *opts)
2103 {
2104         return mount_single (t, flags, opts, gadgetfs_fill_super);
2105 }
2106
2107 static void
2108 gadgetfs_kill_sb (struct super_block *sb)
2109 {
2110         kill_litter_super (sb);
2111         if (the_device) {
2112                 put_dev (the_device);
2113                 the_device = NULL;
2114         }
2115 }
2116
2117 /*----------------------------------------------------------------------*/
2118
2119 static struct file_system_type gadgetfs_type = {
2120         .owner          = THIS_MODULE,
2121         .name           = shortname,
2122         .mount          = gadgetfs_mount,
2123         .kill_sb        = gadgetfs_kill_sb,
2124 };
2125
2126 /*----------------------------------------------------------------------*/
2127
2128 static int __init init (void)
2129 {
2130         int status;
2131
2132         status = register_filesystem (&gadgetfs_type);
2133         if (status == 0)
2134                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2135                         shortname, driver_desc);
2136         return status;
2137 }
2138 module_init (init);
2139
2140 static void __exit cleanup (void)
2141 {
2142         pr_debug ("unregister %s\n", shortname);
2143         unregister_filesystem (&gadgetfs_type);
2144 }
2145 module_exit (cleanup);
2146