USB gadget: gadgetfs dont try to lock before free
[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/$CHIP is configured
58  *   (by writing configuration and device descriptors).  Afterwards it
59  *   may serve as a source of device events, used to handle all control
60  *   requests other than basic enumeration.
61  *
62  * - Then either immediately, or after a SET_CONFIGURATION control request,
63  *   ep_config() is called when each /dev/gadget/ep* file is configured
64  *   (by writing endpoint descriptors).  Afterwards these files are used
65  *   to write() IN data or to read() OUT data.  To halt the endpoint, a
66  *   "wrong direction" request is issued (like reading an IN endpoint).
67  *
68  * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
69  * not possible on all hardware.  For example, precise fault handling with
70  * respect to data left in endpoint fifos after aborted operations; or
71  * selective clearing of endpoint halts, to implement SET_INTERFACE.
72  */
73
74 #define DRIVER_DESC     "USB Gadget filesystem"
75 #define DRIVER_VERSION  "24 Aug 2004"
76
77 static const char driver_desc [] = DRIVER_DESC;
78 static const char shortname [] = "gadgetfs";
79
80 MODULE_DESCRIPTION (DRIVER_DESC);
81 MODULE_AUTHOR ("David Brownell");
82 MODULE_LICENSE ("GPL");
83
84
85 /*----------------------------------------------------------------------*/
86
87 #define GADGETFS_MAGIC          0xaee71ee7
88 #define DMA_ADDR_INVALID        (~(dma_addr_t)0)
89
90 /* /dev/gadget/$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_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_UNCONNECTED,
109         STATE_CONNECTED,
110         STATE_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;
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_DEFER_ENABLE,
192         STATE_EP_ENABLED,
193         STATE_EP_UNBOUND,
194 };
195
196 struct ep_data {
197         struct semaphore                lock;
198         enum ep_state                   state;
199         atomic_t                        count;
200         struct dev_data                 *dev;
201         /* must hold dev->lock before accessing ep or req */
202         struct usb_ep                   *ep;
203         struct usb_request              *req;
204         ssize_t                         status;
205         char                            name [16];
206         struct usb_endpoint_descriptor  desc, hs_desc;
207         struct list_head                epfiles;
208         wait_queue_head_t               wait;
209         struct dentry                   *dentry;
210         struct inode                    *inode;
211 };
212
213 static inline void get_ep (struct ep_data *data)
214 {
215         atomic_inc (&data->count);
216 }
217
218 static void put_ep (struct ep_data *data)
219 {
220         if (likely (!atomic_dec_and_test (&data->count)))
221                 return;
222         put_dev (data->dev);
223         /* needs no more cleanup */
224         BUG_ON (!list_empty (&data->epfiles));
225         BUG_ON (waitqueue_active (&data->wait));
226         kfree (data);
227 }
228
229 /*----------------------------------------------------------------------*/
230
231 /* most "how to use the hardware" policy choices are in userspace:
232  * mapping endpoint roles (which the driver needs) to the capabilities
233  * which the usb controller has.  most of those capabilities are exposed
234  * implicitly, starting with the driver name and then endpoint names.
235  */
236
237 static const char *CHIP;
238
239 /*----------------------------------------------------------------------*/
240
241 /* NOTE:  don't use dev_printk calls before binding to the gadget
242  * at the end of ep0 configuration, or after unbind.
243  */
244
245 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
246 #define xprintk(d,level,fmt,args...) \
247         printk(level "%s: " fmt , shortname , ## args)
248
249 #ifdef DEBUG
250 #define DBG(dev,fmt,args...) \
251         xprintk(dev , KERN_DEBUG , fmt , ## args)
252 #else
253 #define DBG(dev,fmt,args...) \
254         do { } while (0)
255 #endif /* DEBUG */
256
257 #ifdef VERBOSE
258 #define VDEBUG  DBG
259 #else
260 #define VDEBUG(dev,fmt,args...) \
261         do { } while (0)
262 #endif /* DEBUG */
263
264 #define ERROR(dev,fmt,args...) \
265         xprintk(dev , KERN_ERR , fmt , ## args)
266 #define WARN(dev,fmt,args...) \
267         xprintk(dev , KERN_WARNING , fmt , ## args)
268 #define INFO(dev,fmt,args...) \
269         xprintk(dev , KERN_INFO , fmt , ## args)
270
271
272 /*----------------------------------------------------------------------*/
273
274 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
275  *
276  * After opening, configure non-control endpoints.  Then use normal
277  * stream read() and write() requests; and maybe ioctl() to get more
278  * precise FIFO status when recovering from cancellation.
279  */
280
281 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
282 {
283         struct ep_data  *epdata = ep->driver_data;
284
285         if (!req->context)
286                 return;
287         if (req->status)
288                 epdata->status = req->status;
289         else
290                 epdata->status = req->actual;
291         complete ((struct completion *)req->context);
292 }
293
294 /* tasklock endpoint, returning when it's connected.
295  * still need dev->lock to use epdata->ep.
296  */
297 static int
298 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
299 {
300         int     val;
301
302         if (f_flags & O_NONBLOCK) {
303                 if (down_trylock (&epdata->lock) != 0)
304                         goto nonblock;
305                 if (epdata->state != STATE_EP_ENABLED) {
306                         up (&epdata->lock);
307 nonblock:
308                         val = -EAGAIN;
309                 } else
310                         val = 0;
311                 return val;
312         }
313
314         if ((val = down_interruptible (&epdata->lock)) < 0)
315                 return val;
316 newstate:
317         switch (epdata->state) {
318         case STATE_EP_ENABLED:
319                 break;
320         case STATE_EP_DEFER_ENABLE:
321                 DBG (epdata->dev, "%s wait for host\n", epdata->name);
322                 if ((val = wait_event_interruptible (epdata->wait, 
323                                 epdata->state != STATE_EP_DEFER_ENABLE
324                                 || epdata->dev->state == STATE_DEV_UNBOUND
325                                 )) < 0)
326                         goto fail;
327                 goto newstate;
328         // case STATE_EP_DISABLED:              /* "can't happen" */
329         // case STATE_EP_READY:                 /* "can't happen" */
330         default:                                /* error! */
331                 pr_debug ("%s: ep %p not available, state %d\n",
332                                 shortname, epdata, epdata->state);
333                 // FALLTHROUGH
334         case STATE_EP_UNBOUND:                  /* clean disconnect */
335                 val = -ENODEV;
336 fail:
337                 up (&epdata->lock);
338         }
339         return val;
340 }
341
342 static ssize_t
343 ep_io (struct ep_data *epdata, void *buf, unsigned len)
344 {
345         DECLARE_COMPLETION (done);
346         int value;
347
348         spin_lock_irq (&epdata->dev->lock);
349         if (likely (epdata->ep != NULL)) {
350                 struct usb_request      *req = epdata->req;
351
352                 req->context = &done;
353                 req->complete = epio_complete;
354                 req->buf = buf;
355                 req->length = len;
356                 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
357         } else
358                 value = -ENODEV;
359         spin_unlock_irq (&epdata->dev->lock);
360
361         if (likely (value == 0)) {
362                 value = wait_event_interruptible (done.wait, done.done);
363                 if (value != 0) {
364                         spin_lock_irq (&epdata->dev->lock);
365                         if (likely (epdata->ep != NULL)) {
366                                 DBG (epdata->dev, "%s i/o interrupted\n",
367                                                 epdata->name);
368                                 usb_ep_dequeue (epdata->ep, epdata->req);
369                                 spin_unlock_irq (&epdata->dev->lock);
370
371                                 wait_event (done.wait, done.done);
372                                 if (epdata->status == -ECONNRESET)
373                                         epdata->status = -EINTR;
374                         } else {
375                                 spin_unlock_irq (&epdata->dev->lock);
376
377                                 DBG (epdata->dev, "endpoint gone\n");
378                                 epdata->status = -ENODEV;
379                         }
380                 }
381                 return epdata->status;
382         }
383         return value;
384 }
385
386
387 /* handle a synchronous OUT bulk/intr/iso transfer */
388 static ssize_t
389 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
390 {
391         struct ep_data          *data = fd->private_data;
392         void                    *kbuf;
393         ssize_t                 value;
394
395         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
396                 return value;
397
398         /* halt any endpoint by doing a "wrong direction" i/o call */
399         if (data->desc.bEndpointAddress & USB_DIR_IN) {
400                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
401                                 == USB_ENDPOINT_XFER_ISOC)
402                         return -EINVAL;
403                 DBG (data->dev, "%s halt\n", data->name);
404                 spin_lock_irq (&data->dev->lock);
405                 if (likely (data->ep != NULL))
406                         usb_ep_set_halt (data->ep);
407                 spin_unlock_irq (&data->dev->lock);
408                 up (&data->lock);
409                 return -EBADMSG;
410         }
411
412         /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
413
414         value = -ENOMEM;
415         kbuf = kmalloc (len, SLAB_KERNEL);
416         if (unlikely (!kbuf))
417                 goto free1;
418
419         value = ep_io (data, kbuf, len);
420         VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
421                 data->name, len, (int) value);
422         if (value >= 0 && copy_to_user (buf, kbuf, value))
423                 value = -EFAULT;
424
425 free1:
426         up (&data->lock);
427         kfree (kbuf);
428         return value;
429 }
430
431 /* handle a synchronous IN bulk/intr/iso transfer */
432 static ssize_t
433 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
434 {
435         struct ep_data          *data = fd->private_data;
436         void                    *kbuf;
437         ssize_t                 value;
438
439         if ((value = get_ready_ep (fd->f_flags, data)) < 0)
440                 return value;
441
442         /* halt any endpoint by doing a "wrong direction" i/o call */
443         if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
444                 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
445                                 == USB_ENDPOINT_XFER_ISOC)
446                         return -EINVAL;
447                 DBG (data->dev, "%s halt\n", data->name);
448                 spin_lock_irq (&data->dev->lock);
449                 if (likely (data->ep != NULL))
450                         usb_ep_set_halt (data->ep);
451                 spin_unlock_irq (&data->dev->lock);
452                 up (&data->lock);
453                 return -EBADMSG;
454         }
455
456         /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
457
458         value = -ENOMEM;
459         kbuf = kmalloc (len, SLAB_KERNEL);
460         if (!kbuf)
461                 goto free1;
462         if (copy_from_user (kbuf, buf, len)) {
463                 value = -EFAULT;
464                 goto free1;
465         }
466
467         value = ep_io (data, kbuf, len);
468         VDEBUG (data->dev, "%s write %zu IN, status %d\n",
469                 data->name, len, (int) value);
470 free1:
471         up (&data->lock);
472         kfree (kbuf);
473         return value;
474 }
475
476 static int
477 ep_release (struct inode *inode, struct file *fd)
478 {
479         struct ep_data          *data = fd->private_data;
480         int value;
481
482         if ((value = down_interruptible(&data->lock)) < 0)
483                 return value;
484
485         /* clean up if this can be reopened */
486         if (data->state != STATE_EP_UNBOUND) {
487                 data->state = STATE_EP_DISABLED;
488                 data->desc.bDescriptorType = 0;
489                 data->hs_desc.bDescriptorType = 0;
490                 usb_ep_disable(data->ep);
491         }
492         up (&data->lock);
493         put_ep (data);
494         return 0;
495 }
496
497 static int ep_ioctl (struct inode *inode, struct file *fd,
498                 unsigned code, unsigned long value)
499 {
500         struct ep_data          *data = fd->private_data;
501         int                     status;
502
503         if ((status = get_ready_ep (fd->f_flags, data)) < 0)
504                 return status;
505
506         spin_lock_irq (&data->dev->lock);
507         if (likely (data->ep != NULL)) {
508                 switch (code) {
509                 case GADGETFS_FIFO_STATUS:
510                         status = usb_ep_fifo_status (data->ep);
511                         break;
512                 case GADGETFS_FIFO_FLUSH:
513                         usb_ep_fifo_flush (data->ep);
514                         break;
515                 case GADGETFS_CLEAR_HALT:
516                         status = usb_ep_clear_halt (data->ep);
517                         break;
518                 default:
519                         status = -ENOTTY;
520                 }
521         } else
522                 status = -ENODEV;
523         spin_unlock_irq (&data->dev->lock);
524         up (&data->lock);
525         return status;
526 }
527
528 /*----------------------------------------------------------------------*/
529
530 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
531
532 struct kiocb_priv {
533         struct usb_request      *req;
534         struct ep_data          *epdata;
535         void                    *buf;
536         char __user             *ubuf;          /* NULL for writes */
537         unsigned                actual;
538 };
539
540 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
541 {
542         struct kiocb_priv       *priv = iocb->private;
543         struct ep_data          *epdata;
544         int                     value;
545
546         local_irq_disable();
547         epdata = priv->epdata;
548         // spin_lock(&epdata->dev->lock);
549         kiocbSetCancelled(iocb);
550         if (likely(epdata && epdata->ep && priv->req))
551                 value = usb_ep_dequeue (epdata->ep, priv->req);
552         else
553                 value = -EINVAL;
554         // spin_unlock(&epdata->dev->lock);
555         local_irq_enable();
556
557         aio_put_req(iocb);
558         return value;
559 }
560
561 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
562 {
563         struct kiocb_priv       *priv = iocb->private;
564         ssize_t                 status = priv->actual;
565
566         /* we "retry" to get the right mm context for this: */
567         status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
568         if (unlikely(0 != status))
569                 status = -EFAULT;
570         else
571                 status = priv->actual;
572         kfree(priv->buf);
573         kfree(priv);
574         return status;
575 }
576
577 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
578 {
579         struct kiocb            *iocb = req->context;
580         struct kiocb_priv       *priv = iocb->private;
581         struct ep_data          *epdata = priv->epdata;
582
583         /* lock against disconnect (and ideally, cancel) */
584         spin_lock(&epdata->dev->lock);
585         priv->req = NULL;
586         priv->epdata = NULL;
587         if (priv->ubuf == NULL
588                         || unlikely(req->actual == 0)
589                         || unlikely(kiocbIsCancelled(iocb))) {
590                 kfree(req->buf);
591                 kfree(priv);
592                 iocb->private = NULL;
593                 /* aio_complete() reports bytes-transferred _and_ faults */
594                 if (unlikely(kiocbIsCancelled(iocb)))
595                         aio_put_req(iocb);
596                 else
597                         aio_complete(iocb,
598                                 req->actual ? req->actual : req->status,
599                                 req->status);
600         } else {
601                 /* retry() won't report both; so we hide some faults */
602                 if (unlikely(0 != req->status))
603                         DBG(epdata->dev, "%s fault %d len %d\n",
604                                 ep->name, req->status, req->actual);
605
606                 priv->buf = req->buf;
607                 priv->actual = req->actual;
608                 kick_iocb(iocb);
609         }
610         spin_unlock(&epdata->dev->lock);
611
612         usb_ep_free_request(ep, req);
613         put_ep(epdata);
614 }
615
616 static ssize_t
617 ep_aio_rwtail(
618         struct kiocb    *iocb,
619         char            *buf,
620         size_t          len,
621         struct ep_data  *epdata,
622         char __user     *ubuf
623 )
624 {
625         struct kiocb_priv       *priv;
626         struct usb_request      *req;
627         ssize_t                 value;
628
629         priv = kmalloc(sizeof *priv, GFP_KERNEL);
630         if (!priv) {
631                 value = -ENOMEM;
632 fail:
633                 kfree(buf);
634                 return value;
635         }
636         iocb->private = priv;
637         priv->ubuf = ubuf;
638
639         value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
640         if (unlikely(value < 0)) {
641                 kfree(priv);
642                 goto fail;
643         }
644
645         iocb->ki_cancel = ep_aio_cancel;
646         get_ep(epdata);
647         priv->epdata = epdata;
648         priv->actual = 0;
649
650         /* each kiocb is coupled to one usb_request, but we can't
651          * allocate or submit those if the host disconnected.
652          */
653         spin_lock_irq(&epdata->dev->lock);
654         if (likely(epdata->ep)) {
655                 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
656                 if (likely(req)) {
657                         priv->req = req;
658                         req->buf = buf;
659                         req->length = len;
660                         req->complete = ep_aio_complete;
661                         req->context = iocb;
662                         value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
663                         if (unlikely(0 != value))
664                                 usb_ep_free_request(epdata->ep, req);
665                 } else
666                         value = -EAGAIN;
667         } else
668                 value = -ENODEV;
669         spin_unlock_irq(&epdata->dev->lock);
670
671         up(&epdata->lock);
672
673         if (unlikely(value)) {
674                 kfree(priv);
675                 put_ep(epdata);
676         } else
677                 value = (ubuf ? -EIOCBRETRY : -EIOCBQUEUED);
678         return value;
679 }
680
681 static ssize_t
682 ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
683 {
684         struct ep_data          *epdata = iocb->ki_filp->private_data;
685         char                    *buf;
686
687         if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
688                 return -EINVAL;
689         buf = kmalloc(len, GFP_KERNEL);
690         if (unlikely(!buf))
691                 return -ENOMEM;
692         iocb->ki_retry = ep_aio_read_retry;
693         return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
694 }
695
696 static ssize_t
697 ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
698 {
699         struct ep_data          *epdata = iocb->ki_filp->private_data;
700         char                    *buf;
701
702         if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
703                 return -EINVAL;
704         buf = kmalloc(len, GFP_KERNEL);
705         if (unlikely(!buf))
706                 return -ENOMEM;
707         if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
708                 kfree(buf);
709                 return -EFAULT;
710         }
711         return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
712 }
713
714 /*----------------------------------------------------------------------*/
715
716 /* used after endpoint configuration */
717 static const struct file_operations ep_io_operations = {
718         .owner =        THIS_MODULE,
719         .llseek =       no_llseek,
720
721         .read =         ep_read,
722         .write =        ep_write,
723         .ioctl =        ep_ioctl,
724         .release =      ep_release,
725
726         .aio_read =     ep_aio_read,
727         .aio_write =    ep_aio_write,
728 };
729
730 /* ENDPOINT INITIALIZATION
731  *
732  *     fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
733  *     status = write (fd, descriptors, sizeof descriptors)
734  *
735  * That write establishes the endpoint configuration, configuring
736  * the controller to process bulk, interrupt, or isochronous transfers
737  * at the right maxpacket size, and so on.
738  *
739  * The descriptors are message type 1, identified by a host order u32
740  * at the beginning of what's written.  Descriptor order is: full/low
741  * speed descriptor, then optional high speed descriptor.
742  */
743 static ssize_t
744 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
745 {
746         struct ep_data          *data = fd->private_data;
747         struct usb_ep           *ep;
748         u32                     tag;
749         int                     value, length = len;
750
751         if ((value = down_interruptible (&data->lock)) < 0)
752                 return value;
753
754         if (data->state != STATE_EP_READY) {
755                 value = -EL2HLT;
756                 goto fail;
757         }
758
759         value = len;
760         if (len < USB_DT_ENDPOINT_SIZE + 4)
761                 goto fail0;
762
763         /* we might need to change message format someday */
764         if (copy_from_user (&tag, buf, 4)) {
765                 goto fail1;
766         }
767         if (tag != 1) {
768                 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
769                 goto fail0;
770         }
771         buf += 4;
772         len -= 4;
773
774         /* NOTE:  audio endpoint extensions not accepted here;
775          * just don't include the extra bytes.
776          */
777
778         /* full/low speed descriptor, then high speed */
779         if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
780                 goto fail1;
781         }
782         if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
783                         || data->desc.bDescriptorType != USB_DT_ENDPOINT)
784                 goto fail0;
785         if (len != USB_DT_ENDPOINT_SIZE) {
786                 if (len != 2 * USB_DT_ENDPOINT_SIZE)
787                         goto fail0;
788                 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
789                                         USB_DT_ENDPOINT_SIZE)) {
790                         goto fail1;
791                 }
792                 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
793                                 || data->hs_desc.bDescriptorType
794                                         != USB_DT_ENDPOINT) {
795                         DBG(data->dev, "config %s, bad hs length or type\n",
796                                         data->name);
797                         goto fail0;
798                 }
799         }
800
801         spin_lock_irq (&data->dev->lock);
802         if (data->dev->state == STATE_DEV_UNBOUND) {
803                 value = -ENOENT;
804                 goto gone;
805         } else if ((ep = data->ep) == NULL) {
806                 value = -ENODEV;
807                 goto gone;
808         }
809         switch (data->dev->gadget->speed) {
810         case USB_SPEED_LOW:
811         case USB_SPEED_FULL:
812                 value = usb_ep_enable (ep, &data->desc);
813                 if (value == 0)
814                         data->state = STATE_EP_ENABLED;
815                 break;
816 #ifdef  CONFIG_USB_GADGET_DUALSPEED
817         case USB_SPEED_HIGH:
818                 /* fails if caller didn't provide that descriptor... */
819                 value = usb_ep_enable (ep, &data->hs_desc);
820                 if (value == 0)
821                         data->state = STATE_EP_ENABLED;
822                 break;
823 #endif
824         default:
825                 DBG (data->dev, "unconnected, %s init deferred\n",
826                                 data->name);
827                 data->state = STATE_EP_DEFER_ENABLE;
828         }
829         if (value == 0) {
830                 fd->f_op = &ep_io_operations;
831                 value = length;
832         }
833 gone:
834         spin_unlock_irq (&data->dev->lock);
835         if (value < 0) {
836 fail:
837                 data->desc.bDescriptorType = 0;
838                 data->hs_desc.bDescriptorType = 0;
839         }
840         up (&data->lock);
841         return value;
842 fail0:
843         value = -EINVAL;
844         goto fail;
845 fail1:
846         value = -EFAULT;
847         goto fail;
848 }
849
850 static int
851 ep_open (struct inode *inode, struct file *fd)
852 {
853         struct ep_data          *data = inode->i_private;
854         int                     value = -EBUSY;
855
856         if (down_interruptible (&data->lock) != 0)
857                 return -EINTR;
858         spin_lock_irq (&data->dev->lock);
859         if (data->dev->state == STATE_DEV_UNBOUND)
860                 value = -ENOENT;
861         else if (data->state == STATE_EP_DISABLED) {
862                 value = 0;
863                 data->state = STATE_EP_READY;
864                 get_ep (data);
865                 fd->private_data = data;
866                 VDEBUG (data->dev, "%s ready\n", data->name);
867         } else
868                 DBG (data->dev, "%s state %d\n",
869                         data->name, data->state);
870         spin_unlock_irq (&data->dev->lock);
871         up (&data->lock);
872         return value;
873 }
874
875 /* used before endpoint configuration */
876 static const struct file_operations ep_config_operations = {
877         .owner =        THIS_MODULE,
878         .llseek =       no_llseek,
879
880         .open =         ep_open,
881         .write =        ep_config,
882         .release =      ep_release,
883 };
884
885 /*----------------------------------------------------------------------*/
886
887 /* EP0 IMPLEMENTATION can be partly in userspace.
888  *
889  * Drivers that use this facility receive various events, including
890  * control requests the kernel doesn't handle.  Drivers that don't
891  * use this facility may be too simple-minded for real applications.
892  */
893
894 static inline void ep0_readable (struct dev_data *dev)
895 {
896         wake_up (&dev->wait);
897         kill_fasync (&dev->fasync, SIGIO, POLL_IN);
898 }
899
900 static void clean_req (struct usb_ep *ep, struct usb_request *req)
901 {
902         struct dev_data         *dev = ep->driver_data;
903
904         if (req->buf != dev->rbuf) {
905                 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
906                 req->buf = dev->rbuf;
907                 req->dma = DMA_ADDR_INVALID;
908         }
909         req->complete = epio_complete;
910         dev->setup_out_ready = 0;
911 }
912
913 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
914 {
915         struct dev_data         *dev = ep->driver_data;
916         int                     free = 1;
917
918         /* for control OUT, data must still get to userspace */
919         if (!dev->setup_in) {
920                 dev->setup_out_error = (req->status != 0);
921                 if (!dev->setup_out_error)
922                         free = 0;
923                 dev->setup_out_ready = 1;
924                 ep0_readable (dev);
925         } else if (dev->state == STATE_SETUP)
926                 dev->state = STATE_CONNECTED;
927
928         /* clean up as appropriate */
929         if (free && req->buf != &dev->rbuf)
930                 clean_req (ep, req);
931         req->complete = epio_complete;
932 }
933
934 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
935 {
936         struct dev_data *dev = ep->driver_data;
937
938         if (dev->setup_out_ready) {
939                 DBG (dev, "ep0 request busy!\n");
940                 return -EBUSY;
941         }
942         if (len > sizeof (dev->rbuf))
943                 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
944         if (req->buf == 0) {
945                 req->buf = dev->rbuf;
946                 return -ENOMEM;
947         }
948         req->complete = ep0_complete;
949         req->length = len;
950         req->zero = 0;
951         return 0;
952 }
953
954 static ssize_t
955 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
956 {
957         struct dev_data                 *dev = fd->private_data;
958         ssize_t                         retval;
959         enum ep0_state                  state;
960
961         spin_lock_irq (&dev->lock);
962
963         /* report fd mode change before acting on it */
964         if (dev->setup_abort) {
965                 dev->setup_abort = 0;
966                 retval = -EIDRM;
967                 goto done;
968         }
969
970         /* control DATA stage */
971         if ((state = dev->state) == STATE_SETUP) {
972
973                 if (dev->setup_in) {            /* stall IN */
974                         VDEBUG(dev, "ep0in stall\n");
975                         (void) usb_ep_set_halt (dev->gadget->ep0);
976                         retval = -EL2HLT;
977                         dev->state = STATE_CONNECTED;
978
979                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
980                         struct usb_ep           *ep = dev->gadget->ep0;
981                         struct usb_request      *req = dev->req;
982
983                         if ((retval = setup_req (ep, req, 0)) == 0)
984                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
985                         dev->state = STATE_CONNECTED;
986
987                         /* assume that was SET_CONFIGURATION */
988                         if (dev->current_config) {
989                                 unsigned power;
990 #ifdef  CONFIG_USB_GADGET_DUALSPEED
991                                 if (dev->gadget->speed == USB_SPEED_HIGH)
992                                         power = dev->hs_config->bMaxPower;
993                                 else
994 #endif
995                                         power = dev->config->bMaxPower;
996                                 usb_gadget_vbus_draw(dev->gadget, 2 * power);
997                         }
998
999                 } else {                        /* collect OUT data */
1000                         if ((fd->f_flags & O_NONBLOCK) != 0
1001                                         && !dev->setup_out_ready) {
1002                                 retval = -EAGAIN;
1003                                 goto done;
1004                         }
1005                         spin_unlock_irq (&dev->lock);
1006                         retval = wait_event_interruptible (dev->wait,
1007                                         dev->setup_out_ready != 0);
1008
1009                         /* FIXME state could change from under us */
1010                         spin_lock_irq (&dev->lock);
1011                         if (retval)
1012                                 goto done;
1013                         if (dev->setup_out_error)
1014                                 retval = -EIO;
1015                         else {
1016                                 len = min (len, (size_t)dev->req->actual);
1017 // FIXME don't call this with the spinlock held ...
1018                                 if (copy_to_user (buf, &dev->req->buf, len))
1019                                         retval = -EFAULT;
1020                                 clean_req (dev->gadget->ep0, dev->req);
1021                                 /* NOTE userspace can't yet choose to stall */
1022                         }
1023                 }
1024                 goto done;
1025         }
1026
1027         /* else normal: return event data */
1028         if (len < sizeof dev->event [0]) {
1029                 retval = -EINVAL;
1030                 goto done;
1031         }
1032         len -= len % sizeof (struct usb_gadgetfs_event);
1033         dev->usermode_setup = 1;
1034
1035 scan:
1036         /* return queued events right away */
1037         if (dev->ev_next != 0) {
1038                 unsigned                i, n;
1039                 int                     tmp = dev->ev_next;
1040
1041                 len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
1042                 n = len / sizeof (struct usb_gadgetfs_event);
1043
1044                 /* ep0 can't deliver events when STATE_SETUP */
1045                 for (i = 0; i < n; i++) {
1046                         if (dev->event [i].type == GADGETFS_SETUP) {
1047                                 len = i + 1;
1048                                 len *= sizeof (struct usb_gadgetfs_event);
1049                                 n = 0;
1050                                 break;
1051                         }
1052                 }
1053                 spin_unlock_irq (&dev->lock);
1054                 if (copy_to_user (buf, &dev->event, len))
1055                         retval = -EFAULT;
1056                 else
1057                         retval = len;
1058                 if (len > 0) {
1059                         len /= sizeof (struct usb_gadgetfs_event);
1060
1061                         /* NOTE this doesn't guard against broken drivers;
1062                          * concurrent ep0 readers may lose events.
1063                          */
1064                         spin_lock_irq (&dev->lock);
1065                         dev->ev_next -= len;
1066                         if (dev->ev_next != 0)
1067                                 memmove (&dev->event, &dev->event [len],
1068                                         sizeof (struct usb_gadgetfs_event)
1069                                                 * (tmp - len));
1070                         if (n == 0)
1071                                 dev->state = STATE_SETUP;
1072                         spin_unlock_irq (&dev->lock);
1073                 }
1074                 return retval;
1075         }
1076         if (fd->f_flags & O_NONBLOCK) {
1077                 retval = -EAGAIN;
1078                 goto done;
1079         }
1080
1081         switch (state) {
1082         default:
1083                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1084                 retval = -ESRCH;
1085                 break;
1086         case STATE_UNCONNECTED:
1087         case STATE_CONNECTED:
1088                 spin_unlock_irq (&dev->lock);
1089                 DBG (dev, "%s wait\n", __FUNCTION__);
1090
1091                 /* wait for events */
1092                 retval = wait_event_interruptible (dev->wait,
1093                                 dev->ev_next != 0);
1094                 if (retval < 0)
1095                         return retval;
1096                 spin_lock_irq (&dev->lock);
1097                 goto scan;
1098         }
1099
1100 done:
1101         spin_unlock_irq (&dev->lock);
1102         return retval;
1103 }
1104
1105 static struct usb_gadgetfs_event *
1106 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1107 {
1108         struct usb_gadgetfs_event       *event;
1109         unsigned                        i;
1110
1111         switch (type) {
1112         /* these events purge the queue */
1113         case GADGETFS_DISCONNECT:
1114                 if (dev->state == STATE_SETUP)
1115                         dev->setup_abort = 1;
1116                 // FALL THROUGH
1117         case GADGETFS_CONNECT:
1118                 dev->ev_next = 0;
1119                 break;
1120         case GADGETFS_SETUP:            /* previous request timed out */
1121         case GADGETFS_SUSPEND:          /* same effect */
1122                 /* these events can't be repeated */
1123                 for (i = 0; i != dev->ev_next; i++) {
1124                         if (dev->event [i].type != type)
1125                                 continue;
1126                         DBG (dev, "discard old event %d\n", type);
1127                         dev->ev_next--;
1128                         if (i == dev->ev_next)
1129                                 break;
1130                         /* indices start at zero, for simplicity */
1131                         memmove (&dev->event [i], &dev->event [i + 1],
1132                                 sizeof (struct usb_gadgetfs_event)
1133                                         * (dev->ev_next - i));
1134                 }
1135                 break;
1136         default:
1137                 BUG ();
1138         }
1139         event = &dev->event [dev->ev_next++];
1140         BUG_ON (dev->ev_next > N_EVENT);
1141         VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
1142         memset (event, 0, sizeof *event);
1143         event->type = type;
1144         return event;
1145 }
1146
1147 static ssize_t
1148 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1149 {
1150         struct dev_data         *dev = fd->private_data;
1151         ssize_t                 retval = -ESRCH;
1152
1153         spin_lock_irq (&dev->lock);
1154
1155         /* report fd mode change before acting on it */
1156         if (dev->setup_abort) {
1157                 dev->setup_abort = 0;
1158                 retval = -EIDRM;
1159
1160         /* data and/or status stage for control request */
1161         } else if (dev->state == STATE_SETUP) {
1162
1163                 /* IN DATA+STATUS caller makes len <= wLength */
1164                 if (dev->setup_in) {
1165                         retval = setup_req (dev->gadget->ep0, dev->req, len);
1166                         if (retval == 0) {
1167                                 spin_unlock_irq (&dev->lock);
1168                                 if (copy_from_user (dev->req->buf, buf, len))
1169                                         retval = -EFAULT;
1170                                 else {
1171                                         if (len < dev->setup_wLength)
1172                                                 dev->req->zero = 1;
1173                                         retval = usb_ep_queue (
1174                                                 dev->gadget->ep0, dev->req,
1175                                                 GFP_KERNEL);
1176                                 }
1177                                 if (retval < 0) {
1178                                         spin_lock_irq (&dev->lock);
1179                                         clean_req (dev->gadget->ep0, dev->req);
1180                                         spin_unlock_irq (&dev->lock);
1181                                 } else
1182                                         retval = len;
1183
1184                                 return retval;
1185                         }
1186
1187                 /* can stall some OUT transfers */
1188                 } else if (dev->setup_can_stall) {
1189                         VDEBUG(dev, "ep0out stall\n");
1190                         (void) usb_ep_set_halt (dev->gadget->ep0);
1191                         retval = -EL2HLT;
1192                         dev->state = STATE_CONNECTED;
1193                 } else {
1194                         DBG(dev, "bogus ep0out stall!\n");
1195                 }
1196         } else
1197                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1198
1199         spin_unlock_irq (&dev->lock);
1200         return retval;
1201 }
1202
1203 static int
1204 ep0_fasync (int f, struct file *fd, int on)
1205 {
1206         struct dev_data         *dev = fd->private_data;
1207         // caller must F_SETOWN before signal delivery happens
1208         VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1209         return fasync_helper (f, fd, on, &dev->fasync);
1210 }
1211
1212 static struct usb_gadget_driver gadgetfs_driver;
1213
1214 static int
1215 dev_release (struct inode *inode, struct file *fd)
1216 {
1217         struct dev_data         *dev = fd->private_data;
1218
1219         /* closing ep0 === shutdown all */
1220
1221         usb_gadget_unregister_driver (&gadgetfs_driver);
1222
1223         /* at this point "good" hardware has disconnected the
1224          * device from USB; the host won't see it any more.
1225          * alternatively, all host requests will time out.
1226          */
1227
1228         fasync_helper (-1, fd, 0, &dev->fasync);
1229         kfree (dev->buf);
1230         dev->buf = NULL;
1231         put_dev (dev);
1232
1233         /* other endpoints were all decoupled from this device */
1234         dev->state = STATE_DEV_DISABLED;
1235         return 0;
1236 }
1237
1238 static unsigned int
1239 ep0_poll (struct file *fd, poll_table *wait)
1240 {
1241        struct dev_data         *dev = fd->private_data;
1242        int                     mask = 0;
1243
1244        poll_wait(fd, &dev->wait, wait);
1245
1246        spin_lock_irq (&dev->lock);
1247
1248        /* report fd mode change before acting on it */
1249        if (dev->setup_abort) {
1250                dev->setup_abort = 0;
1251                mask = POLLHUP;
1252                goto out;
1253        }
1254
1255        if (dev->state == STATE_SETUP) {
1256                if (dev->setup_in || dev->setup_can_stall)
1257                        mask = POLLOUT;
1258        } else {
1259                if (dev->ev_next != 0)
1260                        mask = POLLIN;
1261        }
1262 out:
1263        spin_unlock_irq(&dev->lock);
1264        return mask;
1265 }
1266
1267 static int dev_ioctl (struct inode *inode, struct file *fd,
1268                 unsigned code, unsigned long value)
1269 {
1270         struct dev_data         *dev = fd->private_data;
1271         struct usb_gadget       *gadget = dev->gadget;
1272
1273         if (gadget->ops->ioctl)
1274                 return gadget->ops->ioctl (gadget, code, value);
1275         return -ENOTTY;
1276 }
1277
1278 /* used after device configuration */
1279 static const struct file_operations ep0_io_operations = {
1280         .owner =        THIS_MODULE,
1281         .llseek =       no_llseek,
1282
1283         .read =         ep0_read,
1284         .write =        ep0_write,
1285         .fasync =       ep0_fasync,
1286         .poll =         ep0_poll,
1287         .ioctl =        dev_ioctl,
1288         .release =      dev_release,
1289 };
1290
1291 /*----------------------------------------------------------------------*/
1292
1293 /* The in-kernel gadget driver handles most ep0 issues, in particular
1294  * enumerating the single configuration (as provided from user space).
1295  *
1296  * Unrecognized ep0 requests may be handled in user space.
1297  */
1298
1299 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1300 static void make_qualifier (struct dev_data *dev)
1301 {
1302         struct usb_qualifier_descriptor         qual;
1303         struct usb_device_descriptor            *desc;
1304
1305         qual.bLength = sizeof qual;
1306         qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1307         qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1308
1309         desc = dev->dev;
1310         qual.bDeviceClass = desc->bDeviceClass;
1311         qual.bDeviceSubClass = desc->bDeviceSubClass;
1312         qual.bDeviceProtocol = desc->bDeviceProtocol;
1313
1314         /* assumes ep0 uses the same value for both speeds ... */
1315         qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1316
1317         qual.bNumConfigurations = 1;
1318         qual.bRESERVED = 0;
1319
1320         memcpy (dev->rbuf, &qual, sizeof qual);
1321 }
1322 #endif
1323
1324 static int
1325 config_buf (struct dev_data *dev, u8 type, unsigned index)
1326 {
1327         int             len;
1328 #ifdef CONFIG_USB_GADGET_DUALSPEED
1329         int             hs;
1330 #endif
1331
1332         /* only one configuration */
1333         if (index > 0)
1334                 return -EINVAL;
1335
1336 #ifdef CONFIG_USB_GADGET_DUALSPEED
1337         hs = (dev->gadget->speed == USB_SPEED_HIGH);
1338         if (type == USB_DT_OTHER_SPEED_CONFIG)
1339                 hs = !hs;
1340         if (hs) {
1341                 dev->req->buf = dev->hs_config;
1342                 len = le16_to_cpup (&dev->hs_config->wTotalLength);
1343         } else
1344 #endif
1345         {
1346                 dev->req->buf = dev->config;
1347                 len = le16_to_cpup (&dev->config->wTotalLength);
1348         }
1349         ((u8 *)dev->req->buf) [1] = type;
1350         return len;
1351 }
1352
1353 static int
1354 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1355 {
1356         struct dev_data                 *dev = get_gadget_data (gadget);
1357         struct usb_request              *req = dev->req;
1358         int                             value = -EOPNOTSUPP;
1359         struct usb_gadgetfs_event       *event;
1360         u16                             w_value = le16_to_cpu(ctrl->wValue);
1361         u16                             w_length = le16_to_cpu(ctrl->wLength);
1362
1363         spin_lock (&dev->lock);
1364         dev->setup_abort = 0;
1365         if (dev->state == STATE_UNCONNECTED) {
1366                 struct usb_ep   *ep;
1367                 struct ep_data  *data;
1368
1369                 dev->state = STATE_CONNECTED;
1370                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1371
1372 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1373                 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1374                         ERROR (dev, "no high speed config??\n");
1375                         return -EINVAL;
1376                 }
1377 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1378
1379                 INFO (dev, "connected\n");
1380                 event = next_event (dev, GADGETFS_CONNECT);
1381                 event->u.speed = gadget->speed;
1382                 ep0_readable (dev);
1383
1384                 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
1385                         data = ep->driver_data;
1386                         /* ... down_trylock (&data->lock) ... */
1387                         if (data->state != STATE_EP_DEFER_ENABLE)
1388                                 continue;
1389 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1390                         if (gadget->speed == USB_SPEED_HIGH)
1391                                 value = usb_ep_enable (ep, &data->hs_desc);
1392                         else
1393 #endif  /* CONFIG_USB_GADGET_DUALSPEED */
1394                                 value = usb_ep_enable (ep, &data->desc);
1395                         if (value) {
1396                                 ERROR (dev, "deferred %s enable --> %d\n",
1397                                         data->name, value);
1398                                 continue;
1399                         }
1400                         data->state = STATE_EP_ENABLED;
1401                         wake_up (&data->wait);
1402                         DBG (dev, "woke up %s waiters\n", data->name);
1403                 }
1404
1405         /* host may have given up waiting for response.  we can miss control
1406          * requests handled lower down (device/endpoint status and features);
1407          * then ep0_{read,write} will report the wrong status. controller
1408          * driver will have aborted pending i/o.
1409          */
1410         } else if (dev->state == STATE_SETUP)
1411                 dev->setup_abort = 1;
1412
1413         req->buf = dev->rbuf;
1414         req->dma = DMA_ADDR_INVALID;
1415         req->context = NULL;
1416         value = -EOPNOTSUPP;
1417         switch (ctrl->bRequest) {
1418
1419         case USB_REQ_GET_DESCRIPTOR:
1420                 if (ctrl->bRequestType != USB_DIR_IN)
1421                         goto unrecognized;
1422                 switch (w_value >> 8) {
1423
1424                 case USB_DT_DEVICE:
1425                         value = min (w_length, (u16) sizeof *dev->dev);
1426                         req->buf = dev->dev;
1427                         break;
1428 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1429                 case USB_DT_DEVICE_QUALIFIER:
1430                         if (!dev->hs_config)
1431                                 break;
1432                         value = min (w_length, (u16)
1433                                 sizeof (struct usb_qualifier_descriptor));
1434                         make_qualifier (dev);
1435                         break;
1436                 case USB_DT_OTHER_SPEED_CONFIG:
1437                         // FALLTHROUGH
1438 #endif
1439                 case USB_DT_CONFIG:
1440                         value = config_buf (dev,
1441                                         w_value >> 8,
1442                                         w_value & 0xff);
1443                         if (value >= 0)
1444                                 value = min (w_length, (u16) value);
1445                         break;
1446                 case USB_DT_STRING:
1447                         goto unrecognized;
1448
1449                 default:                // all others are errors
1450                         break;
1451                 }
1452                 break;
1453
1454         /* currently one config, two speeds */
1455         case USB_REQ_SET_CONFIGURATION:
1456                 if (ctrl->bRequestType != 0)
1457                         break;
1458                 if (0 == (u8) w_value) {
1459                         value = 0;
1460                         dev->current_config = 0;
1461                         usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1462                         // user mode expected to disable endpoints
1463                 } else {
1464                         u8      config, power;
1465 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1466                         if (gadget->speed == USB_SPEED_HIGH) {
1467                                 config = dev->hs_config->bConfigurationValue;
1468                                 power = dev->hs_config->bMaxPower;
1469                         } else
1470 #endif
1471                         {
1472                                 config = dev->config->bConfigurationValue;
1473                                 power = dev->config->bMaxPower;
1474                         }
1475
1476                         if (config == (u8) w_value) {
1477                                 value = 0;
1478                                 dev->current_config = config;
1479                                 usb_gadget_vbus_draw(gadget, 2 * power);
1480                         }
1481                 }
1482
1483                 /* report SET_CONFIGURATION like any other control request,
1484                  * except that usermode may not stall this.  the next
1485                  * request mustn't be allowed start until this finishes:
1486                  * endpoints and threads set up, etc.
1487                  *
1488                  * NOTE:  older PXA hardware (before PXA 255: without UDCCFR)
1489                  * has bad/racey automagic that prevents synchronizing here.
1490                  * even kernel mode drivers often miss them.
1491                  */
1492                 if (value == 0) {
1493                         INFO (dev, "configuration #%d\n", dev->current_config);
1494                         if (dev->usermode_setup) {
1495                                 dev->setup_can_stall = 0;
1496                                 goto delegate;
1497                         }
1498                 }
1499                 break;
1500
1501 #ifndef CONFIG_USB_GADGETFS_PXA2XX
1502         /* PXA automagically handles this request too */
1503         case USB_REQ_GET_CONFIGURATION:
1504                 if (ctrl->bRequestType != 0x80)
1505                         break;
1506                 *(u8 *)req->buf = dev->current_config;
1507                 value = min (w_length, (u16) 1);
1508                 break;
1509 #endif
1510
1511         default:
1512 unrecognized:
1513                 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1514                         dev->usermode_setup ? "delegate" : "fail",
1515                         ctrl->bRequestType, ctrl->bRequest,
1516                         w_value, le16_to_cpu(ctrl->wIndex), w_length);
1517
1518                 /* if there's an ep0 reader, don't stall */
1519                 if (dev->usermode_setup) {
1520                         dev->setup_can_stall = 1;
1521 delegate:
1522                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1523                                                 ? 1 : 0;
1524                         dev->setup_wLength = w_length;
1525                         dev->setup_out_ready = 0;
1526                         dev->setup_out_error = 0;
1527                         value = 0;
1528
1529                         /* read DATA stage for OUT right away */
1530                         if (unlikely (!dev->setup_in && w_length)) {
1531                                 value = setup_req (gadget->ep0, dev->req,
1532                                                         w_length);
1533                                 if (value < 0)
1534                                         break;
1535                                 value = usb_ep_queue (gadget->ep0, dev->req,
1536                                                         GFP_ATOMIC);
1537                                 if (value < 0) {
1538                                         clean_req (gadget->ep0, dev->req);
1539                                         break;
1540                                 }
1541
1542                                 /* we can't currently stall these */
1543                                 dev->setup_can_stall = 0;
1544                         }
1545
1546                         /* state changes when reader collects event */
1547                         event = next_event (dev, GADGETFS_SETUP);
1548                         event->u.setup = *ctrl;
1549                         ep0_readable (dev);
1550                         spin_unlock (&dev->lock);
1551                         return 0;
1552                 }
1553         }
1554
1555         /* proceed with data transfer and status phases? */
1556         if (value >= 0 && dev->state != STATE_SETUP) {
1557                 req->length = value;
1558                 req->zero = value < w_length;
1559                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1560                 if (value < 0) {
1561                         DBG (dev, "ep_queue --> %d\n", value);
1562                         req->status = 0;
1563                 }
1564         }
1565
1566         /* device stalls when value < 0 */
1567         spin_unlock (&dev->lock);
1568         return value;
1569 }
1570
1571 static void destroy_ep_files (struct dev_data *dev)
1572 {
1573         struct list_head        *entry, *tmp;
1574
1575         DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1576
1577         /* dev->state must prevent interference */
1578 restart:
1579         spin_lock_irq (&dev->lock);
1580         list_for_each_safe (entry, tmp, &dev->epfiles) {
1581                 struct ep_data  *ep;
1582                 struct inode    *parent;
1583                 struct dentry   *dentry;
1584
1585                 /* break link to FS */
1586                 ep = list_entry (entry, struct ep_data, epfiles);
1587                 list_del_init (&ep->epfiles);
1588                 dentry = ep->dentry;
1589                 ep->dentry = NULL;
1590                 parent = dentry->d_parent->d_inode;
1591
1592                 /* break link to controller */
1593                 if (ep->state == STATE_EP_ENABLED)
1594                         (void) usb_ep_disable (ep->ep);
1595                 ep->state = STATE_EP_UNBOUND;
1596                 usb_ep_free_request (ep->ep, ep->req);
1597                 ep->ep = NULL;
1598                 wake_up (&ep->wait);
1599                 put_ep (ep);
1600
1601                 spin_unlock_irq (&dev->lock);
1602
1603                 /* break link to dcache */
1604                 mutex_lock (&parent->i_mutex);
1605                 d_delete (dentry);
1606                 dput (dentry);
1607                 mutex_unlock (&parent->i_mutex);
1608
1609                 /* fds may still be open */
1610                 goto restart;
1611         }
1612         spin_unlock_irq (&dev->lock);
1613 }
1614
1615
1616 static struct inode *
1617 gadgetfs_create_file (struct super_block *sb, char const *name,
1618                 void *data, const struct file_operations *fops,
1619                 struct dentry **dentry_p);
1620
1621 static int activate_ep_files (struct dev_data *dev)
1622 {
1623         struct usb_ep   *ep;
1624         struct ep_data  *data;
1625
1626         gadget_for_each_ep (ep, dev->gadget) {
1627
1628                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1629                 if (!data)
1630                         goto enomem0;
1631                 data->state = STATE_EP_DISABLED;
1632                 init_MUTEX (&data->lock);
1633                 init_waitqueue_head (&data->wait);
1634
1635                 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1636                 atomic_set (&data->count, 1);
1637                 data->dev = dev;
1638                 get_dev (dev);
1639
1640                 data->ep = ep;
1641                 ep->driver_data = data;
1642
1643                 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1644                 if (!data->req)
1645                         goto enomem1;
1646
1647                 data->inode = gadgetfs_create_file (dev->sb, data->name,
1648                                 data, &ep_config_operations,
1649                                 &data->dentry);
1650                 if (!data->inode)
1651                         goto enomem2;
1652                 list_add_tail (&data->epfiles, &dev->epfiles);
1653         }
1654         return 0;
1655
1656 enomem2:
1657         usb_ep_free_request (ep, data->req);
1658 enomem1:
1659         put_dev (dev);
1660         kfree (data);
1661 enomem0:
1662         DBG (dev, "%s enomem\n", __FUNCTION__);
1663         destroy_ep_files (dev);
1664         return -ENOMEM;
1665 }
1666
1667 static void
1668 gadgetfs_unbind (struct usb_gadget *gadget)
1669 {
1670         struct dev_data         *dev = get_gadget_data (gadget);
1671
1672         DBG (dev, "%s\n", __FUNCTION__);
1673
1674         spin_lock_irq (&dev->lock);
1675         dev->state = STATE_DEV_UNBOUND;
1676         spin_unlock_irq (&dev->lock);
1677
1678         destroy_ep_files (dev);
1679         gadget->ep0->driver_data = NULL;
1680         set_gadget_data (gadget, NULL);
1681
1682         /* we've already been disconnected ... no i/o is active */
1683         if (dev->req)
1684                 usb_ep_free_request (gadget->ep0, dev->req);
1685         DBG (dev, "%s done\n", __FUNCTION__);
1686         put_dev (dev);
1687 }
1688
1689 static struct dev_data          *the_device;
1690
1691 static int
1692 gadgetfs_bind (struct usb_gadget *gadget)
1693 {
1694         struct dev_data         *dev = the_device;
1695
1696         if (!dev)
1697                 return -ESRCH;
1698         if (0 != strcmp (CHIP, gadget->name)) {
1699                 printk (KERN_ERR "%s expected %s controller not %s\n",
1700                         shortname, CHIP, gadget->name);
1701                 return -ENODEV;
1702         }
1703
1704         set_gadget_data (gadget, dev);
1705         dev->gadget = gadget;
1706         gadget->ep0->driver_data = dev;
1707         dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1708
1709         /* preallocate control response and buffer */
1710         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1711         if (!dev->req)
1712                 goto enomem;
1713         dev->req->context = NULL;
1714         dev->req->complete = epio_complete;
1715
1716         if (activate_ep_files (dev) < 0)
1717                 goto enomem;
1718
1719         INFO (dev, "bound to %s driver\n", gadget->name);
1720         dev->state = STATE_UNCONNECTED;
1721         get_dev (dev);
1722         return 0;
1723
1724 enomem:
1725         gadgetfs_unbind (gadget);
1726         return -ENOMEM;
1727 }
1728
1729 static void
1730 gadgetfs_disconnect (struct usb_gadget *gadget)
1731 {
1732         struct dev_data         *dev = get_gadget_data (gadget);
1733
1734         spin_lock (&dev->lock);
1735         if (dev->state == STATE_UNCONNECTED) {
1736                 DBG (dev, "already unconnected\n");
1737                 goto exit;
1738         }
1739         dev->state = STATE_UNCONNECTED;
1740
1741         INFO (dev, "disconnected\n");
1742         next_event (dev, GADGETFS_DISCONNECT);
1743         ep0_readable (dev);
1744 exit:
1745         spin_unlock (&dev->lock);
1746 }
1747
1748 static void
1749 gadgetfs_suspend (struct usb_gadget *gadget)
1750 {
1751         struct dev_data         *dev = get_gadget_data (gadget);
1752
1753         INFO (dev, "suspended from state %d\n", dev->state);
1754         spin_lock (&dev->lock);
1755         switch (dev->state) {
1756         case STATE_SETUP:               // VERY odd... host died??
1757         case STATE_CONNECTED:
1758         case STATE_UNCONNECTED:
1759                 next_event (dev, GADGETFS_SUSPEND);
1760                 ep0_readable (dev);
1761                 /* FALLTHROUGH */
1762         default:
1763                 break;
1764         }
1765         spin_unlock (&dev->lock);
1766 }
1767
1768 static struct usb_gadget_driver gadgetfs_driver = {
1769 #ifdef  CONFIG_USB_GADGET_DUALSPEED
1770         .speed          = USB_SPEED_HIGH,
1771 #else
1772         .speed          = USB_SPEED_FULL,
1773 #endif
1774         .function       = (char *) driver_desc,
1775         .bind           = gadgetfs_bind,
1776         .unbind         = gadgetfs_unbind,
1777         .setup          = gadgetfs_setup,
1778         .disconnect     = gadgetfs_disconnect,
1779         .suspend        = gadgetfs_suspend,
1780
1781         .driver         = {
1782                 .name           = (char *) shortname,
1783         },
1784 };
1785
1786 /*----------------------------------------------------------------------*/
1787
1788 static void gadgetfs_nop(struct usb_gadget *arg) { }
1789
1790 static int gadgetfs_probe (struct usb_gadget *gadget)
1791 {
1792         CHIP = gadget->name;
1793         return -EISNAM;
1794 }
1795
1796 static struct usb_gadget_driver probe_driver = {
1797         .speed          = USB_SPEED_HIGH,
1798         .bind           = gadgetfs_probe,
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 may want to immediately
1826  * initialize them, using the /dev/gadget/ep* files that are available
1827  * as soon as the kernel sees the configuration, or they can wait
1828  * until device configuration and interface altsetting changes create
1829  * the need to configure (or unconfigure) them.
1830  *
1831  * After initialization, the device stays active for as long as that
1832  * $CHIP file is open.  Events may then be read from that descriptor,
1833  * such as configuration notifications.  More complex drivers will handle
1834  * some control requests in user space.
1835  */
1836
1837 static int is_valid_config (struct usb_config_descriptor *config)
1838 {
1839         return config->bDescriptorType == USB_DT_CONFIG
1840                 && config->bLength == USB_DT_CONFIG_SIZE
1841                 && config->bConfigurationValue != 0
1842                 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1843                 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1844         /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1845         /* FIXME check lengths: walk to end */
1846 }
1847
1848 static ssize_t
1849 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1850 {
1851         struct dev_data         *dev = fd->private_data;
1852         ssize_t                 value = len, length = len;
1853         unsigned                total;
1854         u32                     tag;
1855         char                    *kbuf;
1856
1857         if (dev->state != STATE_OPENED)
1858                 return -EEXIST;
1859
1860         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1861                 return -EINVAL;
1862
1863         /* we might need to change message format someday */
1864         if (copy_from_user (&tag, buf, 4))
1865                 return -EFAULT;
1866         if (tag != 0)
1867                 return -EINVAL;
1868         buf += 4;
1869         length -= 4;
1870
1871         kbuf = kmalloc (length, SLAB_KERNEL);
1872         if (!kbuf)
1873                 return -ENOMEM;
1874         if (copy_from_user (kbuf, buf, length)) {
1875                 kfree (kbuf);
1876                 return -EFAULT;
1877         }
1878
1879         spin_lock_irq (&dev->lock);
1880         value = -EINVAL;
1881         if (dev->buf)
1882                 goto fail;
1883         dev->buf = kbuf;
1884
1885         /* full or low speed config */
1886         dev->config = (void *) kbuf;
1887         total = le16_to_cpup (&dev->config->wTotalLength);
1888         if (!is_valid_config (dev->config) || total >= length)
1889                 goto fail;
1890         kbuf += total;
1891         length -= total;
1892
1893         /* optional high speed config */
1894         if (kbuf [1] == USB_DT_CONFIG) {
1895                 dev->hs_config = (void *) kbuf;
1896                 total = le16_to_cpup (&dev->hs_config->wTotalLength);
1897                 if (!is_valid_config (dev->hs_config) || total >= length)
1898                         goto fail;
1899                 kbuf += total;
1900                 length -= total;
1901         }
1902
1903         /* could support multiple configs, using another encoding! */
1904
1905         /* device descriptor (tweaked for paranoia) */
1906         if (length != USB_DT_DEVICE_SIZE)
1907                 goto fail;
1908         dev->dev = (void *)kbuf;
1909         if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1910                         || dev->dev->bDescriptorType != USB_DT_DEVICE
1911                         || dev->dev->bNumConfigurations != 1)
1912                 goto fail;
1913         dev->dev->bNumConfigurations = 1;
1914         dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1915
1916         /* triggers gadgetfs_bind(); then we can enumerate. */
1917         spin_unlock_irq (&dev->lock);
1918         value = usb_gadget_register_driver (&gadgetfs_driver);
1919         if (value != 0) {
1920                 kfree (dev->buf);
1921                 dev->buf = NULL;
1922         } else {
1923                 /* at this point "good" hardware has for the first time
1924                  * let the USB the host see us.  alternatively, if users
1925                  * unplug/replug that will clear all the error state.
1926                  *
1927                  * note:  everything running before here was guaranteed
1928                  * to choke driver model style diagnostics.  from here
1929                  * on, they can work ... except in cleanup paths that
1930                  * kick in after the ep0 descriptor is closed.
1931                  */
1932                 fd->f_op = &ep0_io_operations;
1933                 value = len;
1934         }
1935         return value;
1936
1937 fail:
1938         spin_unlock_irq (&dev->lock);
1939         pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1940         kfree (dev->buf);
1941         dev->buf = NULL;
1942         return value;
1943 }
1944
1945 static int
1946 dev_open (struct inode *inode, struct file *fd)
1947 {
1948         struct dev_data         *dev = inode->i_private;
1949         int                     value = -EBUSY;
1950
1951         if (dev->state == STATE_DEV_DISABLED) {
1952                 dev->ev_next = 0;
1953                 dev->state = STATE_OPENED;
1954                 fd->private_data = dev;
1955                 get_dev (dev);
1956                 value = 0;
1957         }
1958         return value;
1959 }
1960
1961 static const struct file_operations dev_init_operations = {
1962         .owner =        THIS_MODULE,
1963         .llseek =       no_llseek,
1964
1965         .open =         dev_open,
1966         .write =        dev_config,
1967         .fasync =       ep0_fasync,
1968         .ioctl =        dev_ioctl,
1969         .release =      dev_release,
1970 };
1971
1972 /*----------------------------------------------------------------------*/
1973
1974 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1975  *
1976  * Mounting the filesystem creates a controller file, used first for
1977  * device configuration then later for event monitoring.
1978  */
1979
1980
1981 /* FIXME PAM etc could set this security policy without mount options
1982  * if epfiles inherited ownership and permissons from ep0 ...
1983  */
1984
1985 static unsigned default_uid;
1986 static unsigned default_gid;
1987 static unsigned default_perm = S_IRUSR | S_IWUSR;
1988
1989 module_param (default_uid, uint, 0644);
1990 module_param (default_gid, uint, 0644);
1991 module_param (default_perm, uint, 0644);
1992
1993
1994 static struct inode *
1995 gadgetfs_make_inode (struct super_block *sb,
1996                 void *data, const struct file_operations *fops,
1997                 int mode)
1998 {
1999         struct inode *inode = new_inode (sb);
2000
2001         if (inode) {
2002                 inode->i_mode = mode;
2003                 inode->i_uid = default_uid;
2004                 inode->i_gid = default_gid;
2005                 inode->i_blocks = 0;
2006                 inode->i_atime = inode->i_mtime = inode->i_ctime
2007                                 = CURRENT_TIME;
2008                 inode->i_private = data;
2009                 inode->i_fop = fops;
2010         }
2011         return inode;
2012 }
2013
2014 /* creates in fs root directory, so non-renamable and non-linkable.
2015  * so inode and dentry are paired, until device reconfig.
2016  */
2017 static struct inode *
2018 gadgetfs_create_file (struct super_block *sb, char const *name,
2019                 void *data, const struct file_operations *fops,
2020                 struct dentry **dentry_p)
2021 {
2022         struct dentry   *dentry;
2023         struct inode    *inode;
2024
2025         dentry = d_alloc_name(sb->s_root, name);
2026         if (!dentry)
2027                 return NULL;
2028
2029         inode = gadgetfs_make_inode (sb, data, fops,
2030                         S_IFREG | (default_perm & S_IRWXUGO));
2031         if (!inode) {
2032                 dput(dentry);
2033                 return NULL;
2034         }
2035         d_add (dentry, inode);
2036         *dentry_p = dentry;
2037         return inode;
2038 }
2039
2040 static struct super_operations gadget_fs_operations = {
2041         .statfs =       simple_statfs,
2042         .drop_inode =   generic_delete_inode,
2043 };
2044
2045 static int
2046 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2047 {
2048         struct inode    *inode;
2049         struct dentry   *d;
2050         struct dev_data *dev;
2051
2052         if (the_device)
2053                 return -ESRCH;
2054
2055         /* fake probe to determine $CHIP */
2056         (void) usb_gadget_register_driver (&probe_driver);
2057         if (!CHIP)
2058                 return -ENODEV;
2059
2060         /* superblock */
2061         sb->s_blocksize = PAGE_CACHE_SIZE;
2062         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2063         sb->s_magic = GADGETFS_MAGIC;
2064         sb->s_op = &gadget_fs_operations;
2065         sb->s_time_gran = 1;
2066
2067         /* root inode */
2068         inode = gadgetfs_make_inode (sb,
2069                         NULL, &simple_dir_operations,
2070                         S_IFDIR | S_IRUGO | S_IXUGO);
2071         if (!inode)
2072                 goto enomem0;
2073         inode->i_op = &simple_dir_inode_operations;
2074         if (!(d = d_alloc_root (inode)))
2075                 goto enomem1;
2076         sb->s_root = d;
2077
2078         /* the ep0 file is named after the controller we expect;
2079          * user mode code can use it for sanity checks, like we do.
2080          */
2081         dev = dev_new ();
2082         if (!dev)
2083                 goto enomem2;
2084
2085         dev->sb = sb;
2086         if (!gadgetfs_create_file (sb, CHIP,
2087                                 dev, &dev_init_operations,
2088                                 &dev->dentry))
2089                 goto enomem3;
2090
2091         /* other endpoint files are available after hardware setup,
2092          * from binding to a controller.
2093          */
2094         the_device = dev;
2095         return 0;
2096
2097 enomem3:
2098         put_dev (dev);
2099 enomem2:
2100         dput (d);
2101 enomem1:
2102         iput (inode);
2103 enomem0:
2104         return -ENOMEM;
2105 }
2106
2107 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2108 static int
2109 gadgetfs_get_sb (struct file_system_type *t, int flags,
2110                 const char *path, void *opts, struct vfsmount *mnt)
2111 {
2112         return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2113 }
2114
2115 static void
2116 gadgetfs_kill_sb (struct super_block *sb)
2117 {
2118         kill_litter_super (sb);
2119         if (the_device) {
2120                 put_dev (the_device);
2121                 the_device = NULL;
2122         }
2123 }
2124
2125 /*----------------------------------------------------------------------*/
2126
2127 static struct file_system_type gadgetfs_type = {
2128         .owner          = THIS_MODULE,
2129         .name           = shortname,
2130         .get_sb         = gadgetfs_get_sb,
2131         .kill_sb        = gadgetfs_kill_sb,
2132 };
2133
2134 /*----------------------------------------------------------------------*/
2135
2136 static int __init init (void)
2137 {
2138         int status;
2139
2140         status = register_filesystem (&gadgetfs_type);
2141         if (status == 0)
2142                 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2143                         shortname, driver_desc);
2144         return status;
2145 }
2146 module_init (init);
2147
2148 static void __exit cleanup (void)
2149 {
2150         pr_debug ("unregister %s\n", shortname);
2151         unregister_filesystem (&gadgetfs_type);
2152 }
2153 module_exit (cleanup);
2154