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Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[deliverable/linux.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_mode = mode;
1995 inode->i_uid = default_uid;
1996 inode->i_gid = default_gid;
1997 inode->i_atime = inode->i_mtime = inode->i_ctime
1998 = CURRENT_TIME;
1999 inode->i_private = data;
2000 inode->i_fop = fops;
2001 }
2002 return inode;
2003 }
2004
2005 /* creates in fs root directory, so non-renamable and non-linkable.
2006 * so inode and dentry are paired, until device reconfig.
2007 */
2008 static struct inode *
2009 gadgetfs_create_file (struct super_block *sb, char const *name,
2010 void *data, const struct file_operations *fops,
2011 struct dentry **dentry_p)
2012 {
2013 struct dentry *dentry;
2014 struct inode *inode;
2015
2016 dentry = d_alloc_name(sb->s_root, name);
2017 if (!dentry)
2018 return NULL;
2019
2020 inode = gadgetfs_make_inode (sb, data, fops,
2021 S_IFREG | (default_perm & S_IRWXUGO));
2022 if (!inode) {
2023 dput(dentry);
2024 return NULL;
2025 }
2026 d_add (dentry, inode);
2027 *dentry_p = dentry;
2028 return inode;
2029 }
2030
2031 static const struct super_operations gadget_fs_operations = {
2032 .statfs = simple_statfs,
2033 .drop_inode = generic_delete_inode,
2034 };
2035
2036 static int
2037 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2038 {
2039 struct inode *inode;
2040 struct dentry *d;
2041 struct dev_data *dev;
2042
2043 if (the_device)
2044 return -ESRCH;
2045
2046 /* fake probe to determine $CHIP */
2047 (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2048 if (!CHIP)
2049 return -ENODEV;
2050
2051 /* superblock */
2052 sb->s_blocksize = PAGE_CACHE_SIZE;
2053 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2054 sb->s_magic = GADGETFS_MAGIC;
2055 sb->s_op = &gadget_fs_operations;
2056 sb->s_time_gran = 1;
2057
2058 /* root inode */
2059 inode = gadgetfs_make_inode (sb,
2060 NULL, &simple_dir_operations,
2061 S_IFDIR | S_IRUGO | S_IXUGO);
2062 if (!inode)
2063 goto enomem0;
2064 inode->i_op = &simple_dir_inode_operations;
2065 if (!(d = d_alloc_root (inode)))
2066 goto enomem1;
2067 sb->s_root = d;
2068
2069 /* the ep0 file is named after the controller we expect;
2070 * user mode code can use it for sanity checks, like we do.
2071 */
2072 dev = dev_new ();
2073 if (!dev)
2074 goto enomem2;
2075
2076 dev->sb = sb;
2077 if (!gadgetfs_create_file (sb, CHIP,
2078 dev, &dev_init_operations,
2079 &dev->dentry))
2080 goto enomem3;
2081
2082 /* other endpoint files are available after hardware setup,
2083 * from binding to a controller.
2084 */
2085 the_device = dev;
2086 return 0;
2087
2088 enomem3:
2089 put_dev (dev);
2090 enomem2:
2091 dput (d);
2092 enomem1:
2093 iput (inode);
2094 enomem0:
2095 return -ENOMEM;
2096 }
2097
2098 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2099 static int
2100 gadgetfs_get_sb (struct file_system_type *t, int flags,
2101 const char *path, void *opts, struct vfsmount *mnt)
2102 {
2103 return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2104 }
2105
2106 static void
2107 gadgetfs_kill_sb (struct super_block *sb)
2108 {
2109 kill_litter_super (sb);
2110 if (the_device) {
2111 put_dev (the_device);
2112 the_device = NULL;
2113 }
2114 }
2115
2116 /*----------------------------------------------------------------------*/
2117
2118 static struct file_system_type gadgetfs_type = {
2119 .owner = THIS_MODULE,
2120 .name = shortname,
2121 .get_sb = gadgetfs_get_sb,
2122 .kill_sb = gadgetfs_kill_sb,
2123 };
2124
2125 /*----------------------------------------------------------------------*/
2126
2127 static int __init init (void)
2128 {
2129 int status;
2130
2131 status = register_filesystem (&gadgetfs_type);
2132 if (status == 0)
2133 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2134 shortname, driver_desc);
2135 return status;
2136 }
2137 module_init (init);
2138
2139 static void __exit cleanup (void)
2140 {
2141 pr_debug ("unregister %s\n", shortname);
2142 unregister_filesystem (&gadgetfs_type);
2143 }
2144 module_exit (cleanup);
2145
Linux kernel - Deliverables
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