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markers: turn marker_synchronize_unregister() into an inline
[linux/fpc-iii.git] / drivers / usb / gadget / inode.c
blobf4585d3e90d7a54fd4836648e2cb50eed7d7a947
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/slab.h>
34 #include <linux/poll.h>
35 #include <linux/smp_lock.h>
36
37 #include <linux/device.h>
38 #include <linux/moduleparam.h>
39
40 #include <linux/usb/gadgetfs.h>
41 #include <linux/usb/gadget.h>
42
43
44 /*
45 * The gadgetfs API maps each endpoint to a file descriptor so that you
46 * can use standard synchronous read/write calls for I/O. There's some
47 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
48 * drivers show how this works in practice. You can also use AIO to
49 * eliminate I/O gaps between requests, to help when streaming data.
50 *
51 * Key parts that must be USB-specific are protocols defining how the
52 * read/write operations relate to the hardware state machines. There
53 * are two types of files. One type is for the device, implementing ep0.
54 * The other type is for each IN or OUT endpoint. In both cases, the
55 * user mode driver must configure the hardware before using it.
56 *
57 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
58 * (by writing configuration and device descriptors). Afterwards it
59 * may serve as a source of device events, used to handle all control
60 * requests other than basic enumeration.
61 *
62 * - Then, after a SET_CONFIGURATION control request, ep_config() is
63 * called when each /dev/gadget/ep* file is configured (by writing
64 * endpoint descriptors). Afterwards these files are used to write()
65 * IN data or to read() OUT data. To halt the endpoint, a "wrong
66 * direction" request is issued (like reading an IN endpoint).
67 *
68 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
69 * not possible on all hardware. For example, precise fault handling with
70 * respect to data left in endpoint fifos after aborted operations; or
71 * selective clearing of endpoint halts, to implement SET_INTERFACE.
72 */
73
74 #define DRIVER_DESC "USB Gadget filesystem"
75 #define DRIVER_VERSION "24 Aug 2004"
76
77 static const char driver_desc [] = DRIVER_DESC;
78 static const char shortname [] = "gadgetfs";
79
80 MODULE_DESCRIPTION (DRIVER_DESC);
81 MODULE_AUTHOR ("David Brownell");
82 MODULE_LICENSE ("GPL");
83
84
85 /*----------------------------------------------------------------------*/
86
87 #define GADGETFS_MAGIC 0xaee71ee7
88 #define DMA_ADDR_INVALID (~(dma_addr_t)0)
89
90 /* /dev/gadget/$CHIP represents ep0 and the whole device */
91 enum ep0_state {
92 /* DISBLED is the initial state.
93 */
94 STATE_DEV_DISABLED = 0,
95
96 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
97 * ep0/device i/o modes and binding to the controller. Driver
98 * must always write descriptors to initialize the device, then
99 * the device becomes UNCONNECTED until enumeration.
100 */
101 STATE_DEV_OPENED,
102
103 /* From then on, ep0 fd is in either of two basic modes:
104 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
105 * - SETUP: read/write will transfer control data and succeed;
106 * or if "wrong direction", performs protocol stall
107 */
108 STATE_DEV_UNCONNECTED,
109 STATE_DEV_CONNECTED,
110 STATE_DEV_SETUP,
111
112 /* UNBOUND means the driver closed ep0, so the device won't be
113 * accessible again (DEV_DISABLED) until all fds are closed.
114 */
115 STATE_DEV_UNBOUND,
116 };
117
118 /* enough for the whole queue: most events invalidate others */
119 #define N_EVENT 5
120
121 struct dev_data {
122 spinlock_t lock;
123 atomic_t count;
124 enum ep0_state state; /* P: lock */
125 struct usb_gadgetfs_event event [N_EVENT];
126 unsigned ev_next;
127 struct fasync_struct *fasync;
128 u8 current_config;
129
130 /* drivers reading ep0 MUST handle control requests (SETUP)
131 * reported that way; else the host will time out.
132 */
133 unsigned usermode_setup : 1,
134 setup_in : 1,
135 setup_can_stall : 1,
136 setup_out_ready : 1,
137 setup_out_error : 1,
138 setup_abort : 1;
139 unsigned setup_wLength;
140
141 /* the rest is basically write-once */
142 struct usb_config_descriptor *config, *hs_config;
143 struct usb_device_descriptor *dev;
144 struct usb_request *req;
145 struct usb_gadget *gadget;
146 struct list_head epfiles;
147 void *buf;
148 wait_queue_head_t wait;
149 struct super_block *sb;
150 struct dentry *dentry;
151
152 /* except this scratch i/o buffer for ep0 */
153 u8 rbuf [256];
154 };
155
156 static inline void get_dev (struct dev_data *data)
157 {
158 atomic_inc (&data->count);
159 }
160
161 static void put_dev (struct dev_data *data)
162 {
163 if (likely (!atomic_dec_and_test (&data->count)))
164 return;
165 /* needs no more cleanup */
166 BUG_ON (waitqueue_active (&data->wait));
167 kfree (data);
168 }
169
170 static struct dev_data *dev_new (void)
171 {
172 struct dev_data *dev;
173
174 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
175 if (!dev)
176 return NULL;
177 dev->state = STATE_DEV_DISABLED;
178 atomic_set (&dev->count, 1);
179 spin_lock_init (&dev->lock);
180 INIT_LIST_HEAD (&dev->epfiles);
181 init_waitqueue_head (&dev->wait);
182 return dev;
183 }
184
185 /*----------------------------------------------------------------------*/
186
187 /* other /dev/gadget/$ENDPOINT files represent endpoints */
188 enum ep_state {
189 STATE_EP_DISABLED = 0,
190 STATE_EP_READY,
191 STATE_EP_ENABLED,
192 STATE_EP_UNBOUND,
193 };
194
195 struct ep_data {
196 struct semaphore lock;
197 enum ep_state state;
198 atomic_t count;
199 struct dev_data *dev;
200 /* must hold dev->lock before accessing ep or req */
201 struct usb_ep *ep;
202 struct usb_request *req;
203 ssize_t status;
204 char name [16];
205 struct usb_endpoint_descriptor desc, hs_desc;
206 struct list_head epfiles;
207 wait_queue_head_t wait;
208 struct dentry *dentry;
209 struct inode *inode;
210 };
211
212 static inline void get_ep (struct ep_data *data)
213 {
214 atomic_inc (&data->count);
215 }
216
217 static void put_ep (struct ep_data *data)
218 {
219 if (likely (!atomic_dec_and_test (&data->count)))
220 return;
221 put_dev (data->dev);
222 /* needs no more cleanup */
223 BUG_ON (!list_empty (&data->epfiles));
224 BUG_ON (waitqueue_active (&data->wait));
225 kfree (data);
226 }
227
228 /*----------------------------------------------------------------------*/
229
230 /* most "how to use the hardware" policy choices are in userspace:
231 * mapping endpoint roles (which the driver needs) to the capabilities
232 * which the usb controller has. most of those capabilities are exposed
233 * implicitly, starting with the driver name and then endpoint names.
234 */
235
236 static const char *CHIP;
237
238 /*----------------------------------------------------------------------*/
239
240 /* NOTE: don't use dev_printk calls before binding to the gadget
241 * at the end of ep0 configuration, or after unbind.
242 */
243
244 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
245 #define xprintk(d,level,fmt,args...) \
246 printk(level "%s: " fmt , shortname , ## args)
247
248 #ifdef DEBUG
249 #define DBG(dev,fmt,args...) \
250 xprintk(dev , KERN_DEBUG , fmt , ## args)
251 #else
252 #define DBG(dev,fmt,args...) \
253 do { } while (0)
254 #endif /* DEBUG */
255
256 #ifdef VERBOSE_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 (down_trylock (&epdata->lock) != 0)
301 goto nonblock;
302 if (epdata->state != STATE_EP_ENABLED) {
303 up (&epdata->lock);
304 nonblock:
305 val = -EAGAIN;
306 } else
307 val = 0;
308 return val;
309 }
310
311 if ((val = down_interruptible (&epdata->lock)) < 0)
312 return val;
313
314 switch (epdata->state) {
315 case STATE_EP_ENABLED:
316 break;
317 // case STATE_EP_DISABLED: /* "can't happen" */
318 // case STATE_EP_READY: /* "can't happen" */
319 default: /* error! */
320 pr_debug ("%s: ep %p not available, state %d\n",
321 shortname, epdata, epdata->state);
322 // FALLTHROUGH
323 case STATE_EP_UNBOUND: /* clean disconnect */
324 val = -ENODEV;
325 up (&epdata->lock);
326 }
327 return val;
328 }
329
330 static ssize_t
331 ep_io (struct ep_data *epdata, void *buf, unsigned len)
332 {
333 DECLARE_COMPLETION_ONSTACK (done);
334 int value;
335
336 spin_lock_irq (&epdata->dev->lock);
337 if (likely (epdata->ep != NULL)) {
338 struct usb_request *req = epdata->req;
339
340 req->context = &done;
341 req->complete = epio_complete;
342 req->buf = buf;
343 req->length = len;
344 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
345 } else
346 value = -ENODEV;
347 spin_unlock_irq (&epdata->dev->lock);
348
349 if (likely (value == 0)) {
350 value = wait_event_interruptible (done.wait, done.done);
351 if (value != 0) {
352 spin_lock_irq (&epdata->dev->lock);
353 if (likely (epdata->ep != NULL)) {
354 DBG (epdata->dev, "%s i/o interrupted\n",
355 epdata->name);
356 usb_ep_dequeue (epdata->ep, epdata->req);
357 spin_unlock_irq (&epdata->dev->lock);
358
359 wait_event (done.wait, done.done);
360 if (epdata->status == -ECONNRESET)
361 epdata->status = -EINTR;
362 } else {
363 spin_unlock_irq (&epdata->dev->lock);
364
365 DBG (epdata->dev, "endpoint gone\n");
366 epdata->status = -ENODEV;
367 }
368 }
369 return epdata->status;
370 }
371 return value;
372 }
373
374
375 /* handle a synchronous OUT bulk/intr/iso transfer */
376 static ssize_t
377 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
378 {
379 struct ep_data *data = fd->private_data;
380 void *kbuf;
381 ssize_t value;
382
383 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
384 return value;
385
386 /* halt any endpoint by doing a "wrong direction" i/o call */
387 if (data->desc.bEndpointAddress & USB_DIR_IN) {
388 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
389 == USB_ENDPOINT_XFER_ISOC)
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 up (&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 up (&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 (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
432 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
433 == USB_ENDPOINT_XFER_ISOC)
434 return -EINVAL;
435 DBG (data->dev, "%s halt\n", data->name);
436 spin_lock_irq (&data->dev->lock);
437 if (likely (data->ep != NULL))
438 usb_ep_set_halt (data->ep);
439 spin_unlock_irq (&data->dev->lock);
440 up (&data->lock);
441 return -EBADMSG;
442 }
443
444 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
445
446 value = -ENOMEM;
447 kbuf = kmalloc (len, GFP_KERNEL);
448 if (!kbuf)
449 goto free1;
450 if (copy_from_user (kbuf, buf, len)) {
451 value = -EFAULT;
452 goto free1;
453 }
454
455 value = ep_io (data, kbuf, len);
456 VDEBUG (data->dev, "%s write %zu IN, status %d\n",
457 data->name, len, (int) value);
458 free1:
459 up (&data->lock);
460 kfree (kbuf);
461 return value;
462 }
463
464 static int
465 ep_release (struct inode *inode, struct file *fd)
466 {
467 struct ep_data *data = fd->private_data;
468 int value;
469
470 if ((value = down_interruptible(&data->lock)) < 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 up (&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 up (&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 up(&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(epdata->desc.bEndpointAddress & USB_DIR_IN))
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(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
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 if ((value = down_interruptible (&data->lock)) < 0)
770 return value;
771
772 if (data->state != STATE_EP_READY) {
773 value = -EL2HLT;
774 goto fail;
775 }
776
777 value = len;
778 if (len < USB_DT_ENDPOINT_SIZE + 4)
779 goto fail0;
780
781 /* we might need to change message format someday */
782 if (copy_from_user (&tag, buf, 4)) {
783 goto fail1;
784 }
785 if (tag != 1) {
786 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
787 goto fail0;
788 }
789 buf += 4;
790 len -= 4;
791
792 /* NOTE: audio endpoint extensions not accepted here;
793 * just don't include the extra bytes.
794 */
795
796 /* full/low speed descriptor, then high speed */
797 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
798 goto fail1;
799 }
800 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
801 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
802 goto fail0;
803 if (len != USB_DT_ENDPOINT_SIZE) {
804 if (len != 2 * USB_DT_ENDPOINT_SIZE)
805 goto fail0;
806 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
807 USB_DT_ENDPOINT_SIZE)) {
808 goto fail1;
809 }
810 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
811 || data->hs_desc.bDescriptorType
812 != USB_DT_ENDPOINT) {
813 DBG(data->dev, "config %s, bad hs length or type\n",
814 data->name);
815 goto fail0;
816 }
817 }
818
819 spin_lock_irq (&data->dev->lock);
820 if (data->dev->state == STATE_DEV_UNBOUND) {
821 value = -ENOENT;
822 goto gone;
823 } else if ((ep = data->ep) == NULL) {
824 value = -ENODEV;
825 goto gone;
826 }
827 switch (data->dev->gadget->speed) {
828 case USB_SPEED_LOW:
829 case USB_SPEED_FULL:
830 value = usb_ep_enable (ep, &data->desc);
831 if (value == 0)
832 data->state = STATE_EP_ENABLED;
833 break;
834 #ifdef CONFIG_USB_GADGET_DUALSPEED
835 case USB_SPEED_HIGH:
836 /* fails if caller didn't provide that descriptor... */
837 value = usb_ep_enable (ep, &data->hs_desc);
838 if (value == 0)
839 data->state = STATE_EP_ENABLED;
840 break;
841 #endif
842 default:
843 DBG(data->dev, "unconnected, %s init abandoned\n",
844 data->name);
845 value = -EINVAL;
846 }
847 if (value == 0) {
848 fd->f_op = &ep_io_operations;
849 value = length;
850 }
851 gone:
852 spin_unlock_irq (&data->dev->lock);
853 if (value < 0) {
854 fail:
855 data->desc.bDescriptorType = 0;
856 data->hs_desc.bDescriptorType = 0;
857 }
858 up (&data->lock);
859 return value;
860 fail0:
861 value = -EINVAL;
862 goto fail;
863 fail1:
864 value = -EFAULT;
865 goto fail;
866 }
867
868 static int
869 ep_open (struct inode *inode, struct file *fd)
870 {
871 struct ep_data *data = inode->i_private;
872 int value = -EBUSY;
873
874 if (down_interruptible (&data->lock) != 0)
875 return -EINTR;
876 spin_lock_irq (&data->dev->lock);
877 if (data->dev->state == STATE_DEV_UNBOUND)
878 value = -ENOENT;
879 else if (data->state == STATE_EP_DISABLED) {
880 value = 0;
881 data->state = STATE_EP_READY;
882 get_ep (data);
883 fd->private_data = data;
884 VDEBUG (data->dev, "%s ready\n", data->name);
885 } else
886 DBG (data->dev, "%s state %d\n",
887 data->name, data->state);
888 spin_unlock_irq (&data->dev->lock);
889 up (&data->lock);
890 return value;
891 }
892
893 /* used before endpoint configuration */
894 static const struct file_operations ep_config_operations = {
895 .owner = THIS_MODULE,
896 .llseek = no_llseek,
897
898 .open = ep_open,
899 .write = ep_config,
900 .release = ep_release,
901 };
902
903 /*----------------------------------------------------------------------*/
904
905 /* EP0 IMPLEMENTATION can be partly in userspace.
906 *
907 * Drivers that use this facility receive various events, including
908 * control requests the kernel doesn't handle. Drivers that don't
909 * use this facility may be too simple-minded for real applications.
910 */
911
912 static inline void ep0_readable (struct dev_data *dev)
913 {
914 wake_up (&dev->wait);
915 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
916 }
917
918 static void clean_req (struct usb_ep *ep, struct usb_request *req)
919 {
920 struct dev_data *dev = ep->driver_data;
921
922 if (req->buf != dev->rbuf) {
923 kfree(req->buf);
924 req->buf = dev->rbuf;
925 req->dma = DMA_ADDR_INVALID;
926 }
927 req->complete = epio_complete;
928 dev->setup_out_ready = 0;
929 }
930
931 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
932 {
933 struct dev_data *dev = ep->driver_data;
934 unsigned long flags;
935 int free = 1;
936
937 /* for control OUT, data must still get to userspace */
938 spin_lock_irqsave(&dev->lock, flags);
939 if (!dev->setup_in) {
940 dev->setup_out_error = (req->status != 0);
941 if (!dev->setup_out_error)
942 free = 0;
943 dev->setup_out_ready = 1;
944 ep0_readable (dev);
945 }
946
947 /* clean up as appropriate */
948 if (free && req->buf != &dev->rbuf)
949 clean_req (ep, req);
950 req->complete = epio_complete;
951 spin_unlock_irqrestore(&dev->lock, flags);
952 }
953
954 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
955 {
956 struct dev_data *dev = ep->driver_data;
957
958 if (dev->setup_out_ready) {
959 DBG (dev, "ep0 request busy!\n");
960 return -EBUSY;
961 }
962 if (len > sizeof (dev->rbuf))
963 req->buf = kmalloc(len, GFP_ATOMIC);
964 if (req->buf == NULL) {
965 req->buf = dev->rbuf;
966 return -ENOMEM;
967 }
968 req->complete = ep0_complete;
969 req->length = len;
970 req->zero = 0;
971 return 0;
972 }
973
974 static ssize_t
975 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
976 {
977 struct dev_data *dev = fd->private_data;
978 ssize_t retval;
979 enum ep0_state state;
980
981 spin_lock_irq (&dev->lock);
982
983 /* report fd mode change before acting on it */
984 if (dev->setup_abort) {
985 dev->setup_abort = 0;
986 retval = -EIDRM;
987 goto done;
988 }
989
990 /* control DATA stage */
991 if ((state = dev->state) == STATE_DEV_SETUP) {
992
993 if (dev->setup_in) { /* stall IN */
994 VDEBUG(dev, "ep0in stall\n");
995 (void) usb_ep_set_halt (dev->gadget->ep0);
996 retval = -EL2HLT;
997 dev->state = STATE_DEV_CONNECTED;
998
999 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
1000 struct usb_ep *ep = dev->gadget->ep0;
1001 struct usb_request *req = dev->req;
1002
1003 if ((retval = setup_req (ep, req, 0)) == 0)
1004 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1005 dev->state = STATE_DEV_CONNECTED;
1006
1007 /* assume that was SET_CONFIGURATION */
1008 if (dev->current_config) {
1009 unsigned power;
1010
1011 if (gadget_is_dualspeed(dev->gadget)
1012 && (dev->gadget->speed
1013 == USB_SPEED_HIGH))
1014 power = dev->hs_config->bMaxPower;
1015 else
1016 power = dev->config->bMaxPower;
1017 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1018 }
1019
1020 } else { /* collect OUT data */
1021 if ((fd->f_flags & O_NONBLOCK) != 0
1022 && !dev->setup_out_ready) {
1023 retval = -EAGAIN;
1024 goto done;
1025 }
1026 spin_unlock_irq (&dev->lock);
1027 retval = wait_event_interruptible (dev->wait,
1028 dev->setup_out_ready != 0);
1029
1030 /* FIXME state could change from under us */
1031 spin_lock_irq (&dev->lock);
1032 if (retval)
1033 goto done;
1034
1035 if (dev->state != STATE_DEV_SETUP) {
1036 retval = -ECANCELED;
1037 goto done;
1038 }
1039 dev->state = STATE_DEV_CONNECTED;
1040
1041 if (dev->setup_out_error)
1042 retval = -EIO;
1043 else {
1044 len = min (len, (size_t)dev->req->actual);
1045 // FIXME don't call this with the spinlock held ...
1046 if (copy_to_user (buf, dev->req->buf, len))
1047 retval = -EFAULT;
1048 clean_req (dev->gadget->ep0, dev->req);
1049 /* NOTE userspace can't yet choose to stall */
1050 }
1051 }
1052 goto done;
1053 }
1054
1055 /* else normal: return event data */
1056 if (len < sizeof dev->event [0]) {
1057 retval = -EINVAL;
1058 goto done;
1059 }
1060 len -= len % sizeof (struct usb_gadgetfs_event);
1061 dev->usermode_setup = 1;
1062
1063 scan:
1064 /* return queued events right away */
1065 if (dev->ev_next != 0) {
1066 unsigned i, n;
1067
1068 n = len / sizeof (struct usb_gadgetfs_event);
1069 if (dev->ev_next < n)
1070 n = dev->ev_next;
1071
1072 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1073 for (i = 0; i < n; i++) {
1074 if (dev->event [i].type == GADGETFS_SETUP) {
1075 dev->state = STATE_DEV_SETUP;
1076 n = i + 1;
1077 break;
1078 }
1079 }
1080 spin_unlock_irq (&dev->lock);
1081 len = n * sizeof (struct usb_gadgetfs_event);
1082 if (copy_to_user (buf, &dev->event, len))
1083 retval = -EFAULT;
1084 else
1085 retval = len;
1086 if (len > 0) {
1087 /* NOTE this doesn't guard against broken drivers;
1088 * concurrent ep0 readers may lose events.
1089 */
1090 spin_lock_irq (&dev->lock);
1091 if (dev->ev_next > n) {
1092 memmove(&dev->event[0], &dev->event[n],
1093 sizeof (struct usb_gadgetfs_event)
1094 * (dev->ev_next - n));
1095 }
1096 dev->ev_next -= n;
1097 spin_unlock_irq (&dev->lock);
1098 }
1099 return retval;
1100 }
1101 if (fd->f_flags & O_NONBLOCK) {
1102 retval = -EAGAIN;
1103 goto done;
1104 }
1105
1106 switch (state) {
1107 default:
1108 DBG (dev, "fail %s, state %d\n", __func__, state);
1109 retval = -ESRCH;
1110 break;
1111 case STATE_DEV_UNCONNECTED:
1112 case STATE_DEV_CONNECTED:
1113 spin_unlock_irq (&dev->lock);
1114 DBG (dev, "%s wait\n", __func__);
1115
1116 /* wait for events */
1117 retval = wait_event_interruptible (dev->wait,
1118 dev->ev_next != 0);
1119 if (retval < 0)
1120 return retval;
1121 spin_lock_irq (&dev->lock);
1122 goto scan;
1123 }
1124
1125 done:
1126 spin_unlock_irq (&dev->lock);
1127 return retval;
1128 }
1129
1130 static struct usb_gadgetfs_event *
1131 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1132 {
1133 struct usb_gadgetfs_event *event;
1134 unsigned i;
1135
1136 switch (type) {
1137 /* these events purge the queue */
1138 case GADGETFS_DISCONNECT:
1139 if (dev->state == STATE_DEV_SETUP)
1140 dev->setup_abort = 1;
1141 // FALL THROUGH
1142 case GADGETFS_CONNECT:
1143 dev->ev_next = 0;
1144 break;
1145 case GADGETFS_SETUP: /* previous request timed out */
1146 case GADGETFS_SUSPEND: /* same effect */
1147 /* these events can't be repeated */
1148 for (i = 0; i != dev->ev_next; i++) {
1149 if (dev->event [i].type != type)
1150 continue;
1151 DBG(dev, "discard old event[%d] %d\n", i, type);
1152 dev->ev_next--;
1153 if (i == dev->ev_next)
1154 break;
1155 /* indices start at zero, for simplicity */
1156 memmove (&dev->event [i], &dev->event [i + 1],
1157 sizeof (struct usb_gadgetfs_event)
1158 * (dev->ev_next - i));
1159 }
1160 break;
1161 default:
1162 BUG ();
1163 }
1164 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1165 event = &dev->event [dev->ev_next++];
1166 BUG_ON (dev->ev_next > N_EVENT);
1167 memset (event, 0, sizeof *event);
1168 event->type = type;
1169 return event;
1170 }
1171
1172 static ssize_t
1173 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1174 {
1175 struct dev_data *dev = fd->private_data;
1176 ssize_t retval = -ESRCH;
1177
1178 spin_lock_irq (&dev->lock);
1179
1180 /* report fd mode change before acting on it */
1181 if (dev->setup_abort) {
1182 dev->setup_abort = 0;
1183 retval = -EIDRM;
1184
1185 /* data and/or status stage for control request */
1186 } else if (dev->state == STATE_DEV_SETUP) {
1187
1188 /* IN DATA+STATUS caller makes len <= wLength */
1189 if (dev->setup_in) {
1190 retval = setup_req (dev->gadget->ep0, dev->req, len);
1191 if (retval == 0) {
1192 dev->state = STATE_DEV_CONNECTED;
1193 spin_unlock_irq (&dev->lock);
1194 if (copy_from_user (dev->req->buf, buf, len))
1195 retval = -EFAULT;
1196 else {
1197 if (len < dev->setup_wLength)
1198 dev->req->zero = 1;
1199 retval = usb_ep_queue (
1200 dev->gadget->ep0, dev->req,
1201 GFP_KERNEL);
1202 }
1203 if (retval < 0) {
1204 spin_lock_irq (&dev->lock);
1205 clean_req (dev->gadget->ep0, dev->req);
1206 spin_unlock_irq (&dev->lock);
1207 } else
1208 retval = len;
1209
1210 return retval;
1211 }
1212
1213 /* can stall some OUT transfers */
1214 } else if (dev->setup_can_stall) {
1215 VDEBUG(dev, "ep0out stall\n");
1216 (void) usb_ep_set_halt (dev->gadget->ep0);
1217 retval = -EL2HLT;
1218 dev->state = STATE_DEV_CONNECTED;
1219 } else {
1220 DBG(dev, "bogus ep0out stall!\n");
1221 }
1222 } else
1223 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1224
1225 spin_unlock_irq (&dev->lock);
1226 return retval;
1227 }
1228
1229 static int
1230 ep0_fasync (int f, struct file *fd, int on)
1231 {
1232 struct dev_data *dev = fd->private_data;
1233 // caller must F_SETOWN before signal delivery happens
1234 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1235 return fasync_helper (f, fd, on, &dev->fasync);
1236 }
1237
1238 static struct usb_gadget_driver gadgetfs_driver;
1239
1240 static int
1241 dev_release (struct inode *inode, struct file *fd)
1242 {
1243 struct dev_data *dev = fd->private_data;
1244
1245 /* closing ep0 === shutdown all */
1246
1247 usb_gadget_unregister_driver (&gadgetfs_driver);
1248
1249 /* at this point "good" hardware has disconnected the
1250 * device from USB; the host won't see it any more.
1251 * alternatively, all host requests will time out.
1252 */
1253
1254 fasync_helper (-1, fd, 0, &dev->fasync);
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 lock_kernel();
1303 ret = gadget->ops->ioctl (gadget, code, value);
1304 unlock_kernel();
1305 }
1306 return ret;
1307 }
1308
1309 /* used after device configuration */
1310 static const struct file_operations ep0_io_operations = {
1311 .owner = THIS_MODULE,
1312 .llseek = no_llseek,
1313
1314 .read = ep0_read,
1315 .write = ep0_write,
1316 .fasync = ep0_fasync,
1317 .poll = ep0_poll,
1318 .unlocked_ioctl = dev_ioctl,
1319 .release = dev_release,
1320 };
1321
1322 /*----------------------------------------------------------------------*/
1323
1324 /* The in-kernel gadget driver handles most ep0 issues, in particular
1325 * enumerating the single configuration (as provided from user space).
1326 *
1327 * Unrecognized ep0 requests may be handled in user space.
1328 */
1329
1330 #ifdef CONFIG_USB_GADGET_DUALSPEED
1331 static void make_qualifier (struct dev_data *dev)
1332 {
1333 struct usb_qualifier_descriptor qual;
1334 struct usb_device_descriptor *desc;
1335
1336 qual.bLength = sizeof qual;
1337 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1338 qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1339
1340 desc = dev->dev;
1341 qual.bDeviceClass = desc->bDeviceClass;
1342 qual.bDeviceSubClass = desc->bDeviceSubClass;
1343 qual.bDeviceProtocol = desc->bDeviceProtocol;
1344
1345 /* assumes ep0 uses the same value for both speeds ... */
1346 qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1347
1348 qual.bNumConfigurations = 1;
1349 qual.bRESERVED = 0;
1350
1351 memcpy (dev->rbuf, &qual, sizeof qual);
1352 }
1353 #endif
1354
1355 static int
1356 config_buf (struct dev_data *dev, u8 type, unsigned index)
1357 {
1358 int len;
1359 int hs = 0;
1360
1361 /* only one configuration */
1362 if (index > 0)
1363 return -EINVAL;
1364
1365 if (gadget_is_dualspeed(dev->gadget)) {
1366 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1367 if (type == USB_DT_OTHER_SPEED_CONFIG)
1368 hs = !hs;
1369 }
1370 if (hs) {
1371 dev->req->buf = dev->hs_config;
1372 len = le16_to_cpu(dev->hs_config->wTotalLength);
1373 } else {
1374 dev->req->buf = dev->config;
1375 len = le16_to_cpu(dev->config->wTotalLength);
1376 }
1377 ((u8 *)dev->req->buf) [1] = type;
1378 return len;
1379 }
1380
1381 static int
1382 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1383 {
1384 struct dev_data *dev = get_gadget_data (gadget);
1385 struct usb_request *req = dev->req;
1386 int value = -EOPNOTSUPP;
1387 struct usb_gadgetfs_event *event;
1388 u16 w_value = le16_to_cpu(ctrl->wValue);
1389 u16 w_length = le16_to_cpu(ctrl->wLength);
1390
1391 spin_lock (&dev->lock);
1392 dev->setup_abort = 0;
1393 if (dev->state == STATE_DEV_UNCONNECTED) {
1394 if (gadget_is_dualspeed(gadget)
1395 && gadget->speed == USB_SPEED_HIGH
1396 && dev->hs_config == NULL) {
1397 spin_unlock(&dev->lock);
1398 ERROR (dev, "no high speed config??\n");
1399 return -EINVAL;
1400 }
1401
1402 dev->state = STATE_DEV_CONNECTED;
1403 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1404
1405 INFO (dev, "connected\n");
1406 event = next_event (dev, GADGETFS_CONNECT);
1407 event->u.speed = gadget->speed;
1408 ep0_readable (dev);
1409
1410 /* host may have given up waiting for response. we can miss control
1411 * requests handled lower down (device/endpoint status and features);
1412 * then ep0_{read,write} will report the wrong status. controller
1413 * driver will have aborted pending i/o.
1414 */
1415 } else if (dev->state == STATE_DEV_SETUP)
1416 dev->setup_abort = 1;
1417
1418 req->buf = dev->rbuf;
1419 req->dma = DMA_ADDR_INVALID;
1420 req->context = NULL;
1421 value = -EOPNOTSUPP;
1422 switch (ctrl->bRequest) {
1423
1424 case USB_REQ_GET_DESCRIPTOR:
1425 if (ctrl->bRequestType != USB_DIR_IN)
1426 goto unrecognized;
1427 switch (w_value >> 8) {
1428
1429 case USB_DT_DEVICE:
1430 value = min (w_length, (u16) sizeof *dev->dev);
1431 req->buf = dev->dev;
1432 break;
1433 #ifdef CONFIG_USB_GADGET_DUALSPEED
1434 case USB_DT_DEVICE_QUALIFIER:
1435 if (!dev->hs_config)
1436 break;
1437 value = min (w_length, (u16)
1438 sizeof (struct usb_qualifier_descriptor));
1439 make_qualifier (dev);
1440 break;
1441 case USB_DT_OTHER_SPEED_CONFIG:
1442 // FALLTHROUGH
1443 #endif
1444 case USB_DT_CONFIG:
1445 value = config_buf (dev,
1446 w_value >> 8,
1447 w_value & 0xff);
1448 if (value >= 0)
1449 value = min (w_length, (u16) value);
1450 break;
1451 case USB_DT_STRING:
1452 goto unrecognized;
1453
1454 default: // all others are errors
1455 break;
1456 }
1457 break;
1458
1459 /* currently one config, two speeds */
1460 case USB_REQ_SET_CONFIGURATION:
1461 if (ctrl->bRequestType != 0)
1462 goto unrecognized;
1463 if (0 == (u8) w_value) {
1464 value = 0;
1465 dev->current_config = 0;
1466 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1467 // user mode expected to disable endpoints
1468 } else {
1469 u8 config, power;
1470
1471 if (gadget_is_dualspeed(gadget)
1472 && gadget->speed == USB_SPEED_HIGH) {
1473 config = dev->hs_config->bConfigurationValue;
1474 power = dev->hs_config->bMaxPower;
1475 } else {
1476 config = dev->config->bConfigurationValue;
1477 power = dev->config->bMaxPower;
1478 }
1479
1480 if (config == (u8) w_value) {
1481 value = 0;
1482 dev->current_config = config;
1483 usb_gadget_vbus_draw(gadget, 2 * power);
1484 }
1485 }
1486
1487 /* report SET_CONFIGURATION like any other control request,
1488 * except that usermode may not stall this. the next
1489 * request mustn't be allowed start until this finishes:
1490 * endpoints and threads set up, etc.
1491 *
1492 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1493 * has bad/racey automagic that prevents synchronizing here.
1494 * even kernel mode drivers often miss them.
1495 */
1496 if (value == 0) {
1497 INFO (dev, "configuration #%d\n", dev->current_config);
1498 if (dev->usermode_setup) {
1499 dev->setup_can_stall = 0;
1500 goto delegate;
1501 }
1502 }
1503 break;
1504
1505 #ifndef CONFIG_USB_GADGET_PXA25X
1506 /* PXA automagically handles this request too */
1507 case USB_REQ_GET_CONFIGURATION:
1508 if (ctrl->bRequestType != 0x80)
1509 goto unrecognized;
1510 *(u8 *)req->buf = dev->current_config;
1511 value = min (w_length, (u16) 1);
1512 break;
1513 #endif
1514
1515 default:
1516 unrecognized:
1517 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1518 dev->usermode_setup ? "delegate" : "fail",
1519 ctrl->bRequestType, ctrl->bRequest,
1520 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1521
1522 /* if there's an ep0 reader, don't stall */
1523 if (dev->usermode_setup) {
1524 dev->setup_can_stall = 1;
1525 delegate:
1526 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1527 ? 1 : 0;
1528 dev->setup_wLength = w_length;
1529 dev->setup_out_ready = 0;
1530 dev->setup_out_error = 0;
1531 value = 0;
1532
1533 /* read DATA stage for OUT right away */
1534 if (unlikely (!dev->setup_in && w_length)) {
1535 value = setup_req (gadget->ep0, dev->req,
1536 w_length);
1537 if (value < 0)
1538 break;
1539 value = usb_ep_queue (gadget->ep0, dev->req,
1540 GFP_ATOMIC);
1541 if (value < 0) {
1542 clean_req (gadget->ep0, dev->req);
1543 break;
1544 }
1545
1546 /* we can't currently stall these */
1547 dev->setup_can_stall = 0;
1548 }
1549
1550 /* state changes when reader collects event */
1551 event = next_event (dev, GADGETFS_SETUP);
1552 event->u.setup = *ctrl;
1553 ep0_readable (dev);
1554 spin_unlock (&dev->lock);
1555 return 0;
1556 }
1557 }
1558
1559 /* proceed with data transfer and status phases? */
1560 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1561 req->length = value;
1562 req->zero = value < w_length;
1563 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1564 if (value < 0) {
1565 DBG (dev, "ep_queue --> %d\n", value);
1566 req->status = 0;
1567 }
1568 }
1569
1570 /* device stalls when value < 0 */
1571 spin_unlock (&dev->lock);
1572 return value;
1573 }
1574
1575 static void destroy_ep_files (struct dev_data *dev)
1576 {
1577 struct list_head *entry, *tmp;
1578
1579 DBG (dev, "%s %d\n", __func__, dev->state);
1580
1581 /* dev->state must prevent interference */
1582 restart:
1583 spin_lock_irq (&dev->lock);
1584 list_for_each_safe (entry, tmp, &dev->epfiles) {
1585 struct ep_data *ep;
1586 struct inode *parent;
1587 struct dentry *dentry;
1588
1589 /* break link to FS */
1590 ep = list_entry (entry, struct ep_data, epfiles);
1591 list_del_init (&ep->epfiles);
1592 dentry = ep->dentry;
1593 ep->dentry = NULL;
1594 parent = dentry->d_parent->d_inode;
1595
1596 /* break link to controller */
1597 if (ep->state == STATE_EP_ENABLED)
1598 (void) usb_ep_disable (ep->ep);
1599 ep->state = STATE_EP_UNBOUND;
1600 usb_ep_free_request (ep->ep, ep->req);
1601 ep->ep = NULL;
1602 wake_up (&ep->wait);
1603 put_ep (ep);
1604
1605 spin_unlock_irq (&dev->lock);
1606
1607 /* break link to dcache */
1608 mutex_lock (&parent->i_mutex);
1609 d_delete (dentry);
1610 dput (dentry);
1611 mutex_unlock (&parent->i_mutex);
1612
1613 /* fds may still be open */
1614 goto restart;
1615 }
1616 spin_unlock_irq (&dev->lock);
1617 }
1618
1619
1620 static struct inode *
1621 gadgetfs_create_file (struct super_block *sb, char const *name,
1622 void *data, const struct file_operations *fops,
1623 struct dentry **dentry_p);
1624
1625 static int activate_ep_files (struct dev_data *dev)
1626 {
1627 struct usb_ep *ep;
1628 struct ep_data *data;
1629
1630 gadget_for_each_ep (ep, dev->gadget) {
1631
1632 data = kzalloc(sizeof(*data), GFP_KERNEL);
1633 if (!data)
1634 goto enomem0;
1635 data->state = STATE_EP_DISABLED;
1636 init_MUTEX (&data->lock);
1637 init_waitqueue_head (&data->wait);
1638
1639 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1640 atomic_set (&data->count, 1);
1641 data->dev = dev;
1642 get_dev (dev);
1643
1644 data->ep = ep;
1645 ep->driver_data = data;
1646
1647 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1648 if (!data->req)
1649 goto enomem1;
1650
1651 data->inode = gadgetfs_create_file (dev->sb, data->name,
1652 data, &ep_config_operations,
1653 &data->dentry);
1654 if (!data->inode)
1655 goto enomem2;
1656 list_add_tail (&data->epfiles, &dev->epfiles);
1657 }
1658 return 0;
1659
1660 enomem2:
1661 usb_ep_free_request (ep, data->req);
1662 enomem1:
1663 put_dev (dev);
1664 kfree (data);
1665 enomem0:
1666 DBG (dev, "%s enomem\n", __func__);
1667 destroy_ep_files (dev);
1668 return -ENOMEM;
1669 }
1670
1671 static void
1672 gadgetfs_unbind (struct usb_gadget *gadget)
1673 {
1674 struct dev_data *dev = get_gadget_data (gadget);
1675
1676 DBG (dev, "%s\n", __func__);
1677
1678 spin_lock_irq (&dev->lock);
1679 dev->state = STATE_DEV_UNBOUND;
1680 spin_unlock_irq (&dev->lock);
1681
1682 destroy_ep_files (dev);
1683 gadget->ep0->driver_data = NULL;
1684 set_gadget_data (gadget, NULL);
1685
1686 /* we've already been disconnected ... no i/o is active */
1687 if (dev->req)
1688 usb_ep_free_request (gadget->ep0, dev->req);
1689 DBG (dev, "%s done\n", __func__);
1690 put_dev (dev);
1691 }
1692
1693 static struct dev_data *the_device;
1694
1695 static int
1696 gadgetfs_bind (struct usb_gadget *gadget)
1697 {
1698 struct dev_data *dev = the_device;
1699
1700 if (!dev)
1701 return -ESRCH;
1702 if (0 != strcmp (CHIP, gadget->name)) {
1703 pr_err("%s expected %s controller not %s\n",
1704 shortname, CHIP, gadget->name);
1705 return -ENODEV;
1706 }
1707
1708 set_gadget_data (gadget, dev);
1709 dev->gadget = gadget;
1710 gadget->ep0->driver_data = dev;
1711 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1712
1713 /* preallocate control response and buffer */
1714 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1715 if (!dev->req)
1716 goto enomem;
1717 dev->req->context = NULL;
1718 dev->req->complete = epio_complete;
1719
1720 if (activate_ep_files (dev) < 0)
1721 goto enomem;
1722
1723 INFO (dev, "bound to %s driver\n", gadget->name);
1724 spin_lock_irq(&dev->lock);
1725 dev->state = STATE_DEV_UNCONNECTED;
1726 spin_unlock_irq(&dev->lock);
1727 get_dev (dev);
1728 return 0;
1729
1730 enomem:
1731 gadgetfs_unbind (gadget);
1732 return -ENOMEM;
1733 }
1734
1735 static void
1736 gadgetfs_disconnect (struct usb_gadget *gadget)
1737 {
1738 struct dev_data *dev = get_gadget_data (gadget);
1739
1740 spin_lock (&dev->lock);
1741 if (dev->state == STATE_DEV_UNCONNECTED)
1742 goto exit;
1743 dev->state = STATE_DEV_UNCONNECTED;
1744
1745 INFO (dev, "disconnected\n");
1746 next_event (dev, GADGETFS_DISCONNECT);
1747 ep0_readable (dev);
1748 exit:
1749 spin_unlock (&dev->lock);
1750 }
1751
1752 static void
1753 gadgetfs_suspend (struct usb_gadget *gadget)
1754 {
1755 struct dev_data *dev = get_gadget_data (gadget);
1756
1757 INFO (dev, "suspended from state %d\n", dev->state);
1758 spin_lock (&dev->lock);
1759 switch (dev->state) {
1760 case STATE_DEV_SETUP: // VERY odd... host died??
1761 case STATE_DEV_CONNECTED:
1762 case STATE_DEV_UNCONNECTED:
1763 next_event (dev, GADGETFS_SUSPEND);
1764 ep0_readable (dev);
1765 /* FALLTHROUGH */
1766 default:
1767 break;
1768 }
1769 spin_unlock (&dev->lock);
1770 }
1771
1772 static struct usb_gadget_driver gadgetfs_driver = {
1773 #ifdef CONFIG_USB_GADGET_DUALSPEED
1774 .speed = USB_SPEED_HIGH,
1775 #else
1776 .speed = USB_SPEED_FULL,
1777 #endif
1778 .function = (char *) driver_desc,
1779 .bind = gadgetfs_bind,
1780 .unbind = gadgetfs_unbind,
1781 .setup = gadgetfs_setup,
1782 .disconnect = gadgetfs_disconnect,
1783 .suspend = gadgetfs_suspend,
1784
1785 .driver = {
1786 .name = (char *) shortname,
1787 },
1788 };
1789
1790 /*----------------------------------------------------------------------*/
1791
1792 static void gadgetfs_nop(struct usb_gadget *arg) { }
1793
1794 static int gadgetfs_probe (struct usb_gadget *gadget)
1795 {
1796 CHIP = gadget->name;
1797 return -EISNAM;
1798 }
1799
1800 static struct usb_gadget_driver probe_driver = {
1801 .speed = USB_SPEED_HIGH,
1802 .bind = gadgetfs_probe,
1803 .unbind = gadgetfs_nop,
1804 .setup = (void *)gadgetfs_nop,
1805 .disconnect = gadgetfs_nop,
1806 .driver = {
1807 .name = "nop",
1808 },
1809 };
1810
1811
1812 /* DEVICE INITIALIZATION
1813 *
1814 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1815 * status = write (fd, descriptors, sizeof descriptors)
1816 *
1817 * That write establishes the device configuration, so the kernel can
1818 * bind to the controller ... guaranteeing it can handle enumeration
1819 * at all necessary speeds. Descriptor order is:
1820 *
1821 * . message tag (u32, host order) ... for now, must be zero; it
1822 * would change to support features like multi-config devices
1823 * . full/low speed config ... all wTotalLength bytes (with interface,
1824 * class, altsetting, endpoint, and other descriptors)
1825 * . high speed config ... all descriptors, for high speed operation;
1826 * this one's optional except for high-speed hardware
1827 * . device descriptor
1828 *
1829 * Endpoints are not yet enabled. Drivers must wait until device
1830 * configuration and interface altsetting changes create
1831 * the need to configure (or unconfigure) them.
1832 *
1833 * After initialization, the device stays active for as long as that
1834 * $CHIP file is open. Events must then be read from that descriptor,
1835 * such as configuration notifications.
1836 */
1837
1838 static int is_valid_config (struct usb_config_descriptor *config)
1839 {
1840 return config->bDescriptorType == USB_DT_CONFIG
1841 && config->bLength == USB_DT_CONFIG_SIZE
1842 && config->bConfigurationValue != 0
1843 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1844 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1845 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1846 /* FIXME check lengths: walk to end */
1847 }
1848
1849 static ssize_t
1850 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1851 {
1852 struct dev_data *dev = fd->private_data;
1853 ssize_t value = len, length = len;
1854 unsigned total;
1855 u32 tag;
1856 char *kbuf;
1857
1858 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1859 return -EINVAL;
1860
1861 /* we might need to change message format someday */
1862 if (copy_from_user (&tag, buf, 4))
1863 return -EFAULT;
1864 if (tag != 0)
1865 return -EINVAL;
1866 buf += 4;
1867 length -= 4;
1868
1869 kbuf = kmalloc (length, GFP_KERNEL);
1870 if (!kbuf)
1871 return -ENOMEM;
1872 if (copy_from_user (kbuf, buf, length)) {
1873 kfree (kbuf);
1874 return -EFAULT;
1875 }
1876
1877 spin_lock_irq (&dev->lock);
1878 value = -EINVAL;
1879 if (dev->buf)
1880 goto fail;
1881 dev->buf = kbuf;
1882
1883 /* full or low speed config */
1884 dev->config = (void *) kbuf;
1885 total = le16_to_cpu(dev->config->wTotalLength);
1886 if (!is_valid_config (dev->config) || total >= length)
1887 goto fail;
1888 kbuf += total;
1889 length -= total;
1890
1891 /* optional high speed config */
1892 if (kbuf [1] == USB_DT_CONFIG) {
1893 dev->hs_config = (void *) kbuf;
1894 total = le16_to_cpu(dev->hs_config->wTotalLength);
1895 if (!is_valid_config (dev->hs_config) || total >= length)
1896 goto fail;
1897 kbuf += total;
1898 length -= total;
1899 }
1900
1901 /* could support multiple configs, using another encoding! */
1902
1903 /* device descriptor (tweaked for paranoia) */
1904 if (length != USB_DT_DEVICE_SIZE)
1905 goto fail;
1906 dev->dev = (void *)kbuf;
1907 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1908 || dev->dev->bDescriptorType != USB_DT_DEVICE
1909 || dev->dev->bNumConfigurations != 1)
1910 goto fail;
1911 dev->dev->bNumConfigurations = 1;
1912 dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1913
1914 /* triggers gadgetfs_bind(); then we can enumerate. */
1915 spin_unlock_irq (&dev->lock);
1916 value = usb_gadget_register_driver (&gadgetfs_driver);
1917 if (value != 0) {
1918 kfree (dev->buf);
1919 dev->buf = NULL;
1920 } else {
1921 /* at this point "good" hardware has for the first time
1922 * let the USB the host see us. alternatively, if users
1923 * unplug/replug that will clear all the error state.
1924 *
1925 * note: everything running before here was guaranteed
1926 * to choke driver model style diagnostics. from here
1927 * on, they can work ... except in cleanup paths that
1928 * kick in after the ep0 descriptor is closed.
1929 */
1930 fd->f_op = &ep0_io_operations;
1931 value = len;
1932 }
1933 return value;
1934
1935 fail:
1936 spin_unlock_irq (&dev->lock);
1937 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1938 kfree (dev->buf);
1939 dev->buf = NULL;
1940 return value;
1941 }
1942
1943 static int
1944 dev_open (struct inode *inode, struct file *fd)
1945 {
1946 struct dev_data *dev = inode->i_private;
1947 int value = -EBUSY;
1948
1949 spin_lock_irq(&dev->lock);
1950 if (dev->state == STATE_DEV_DISABLED) {
1951 dev->ev_next = 0;
1952 dev->state = STATE_DEV_OPENED;
1953 fd->private_data = dev;
1954 get_dev (dev);
1955 value = 0;
1956 }
1957 spin_unlock_irq(&dev->lock);
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 .unlocked_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
Linux with added FPC-III support