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[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 mutex_unlock(&data->lock);
391 return -EINVAL;
392 }
393 DBG (data->dev, "%s halt\n", data->name);
394 spin_lock_irq (&data->dev->lock);
395 if (likely (data->ep != NULL))
396 usb_ep_set_halt (data->ep);
397 spin_unlock_irq (&data->dev->lock);
398 mutex_unlock(&data->lock);
399 return -EBADMSG;
400 }
401
402 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
403
404 value = -ENOMEM;
405 kbuf = kmalloc (len, GFP_KERNEL);
406 if (unlikely (!kbuf))
407 goto free1;
408
409 value = ep_io (data, kbuf, len);
410 VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
411 data->name, len, (int) value);
412 if (value >= 0 && copy_to_user (buf, kbuf, value))
413 value = -EFAULT;
414
415 free1:
416 mutex_unlock(&data->lock);
417 kfree (kbuf);
418 return value;
419 }
420
421 /* handle a synchronous IN bulk/intr/iso transfer */
422 static ssize_t
423 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
424 {
425 struct ep_data *data = fd->private_data;
426 void *kbuf;
427 ssize_t value;
428
429 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
430 return value;
431
432 /* halt any endpoint by doing a "wrong direction" i/o call */
433 if (!usb_endpoint_dir_in(&data->desc)) {
434 if (usb_endpoint_xfer_isoc(&data->desc)) {
435 mutex_unlock(&data->lock);
436 return -EINVAL;
437 }
438 DBG (data->dev, "%s halt\n", data->name);
439 spin_lock_irq (&data->dev->lock);
440 if (likely (data->ep != NULL))
441 usb_ep_set_halt (data->ep);
442 spin_unlock_irq (&data->dev->lock);
443 mutex_unlock(&data->lock);
444 return -EBADMSG;
445 }
446
447 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
448
449 value = -ENOMEM;
450 kbuf = kmalloc (len, GFP_KERNEL);
451 if (!kbuf)
452 goto free1;
453 if (copy_from_user (kbuf, buf, len)) {
454 value = -EFAULT;
455 goto free1;
456 }
457
458 value = ep_io (data, kbuf, len);
459 VDEBUG (data->dev, "%s write %zu IN, status %d\n",
460 data->name, len, (int) value);
461 free1:
462 mutex_unlock(&data->lock);
463 kfree (kbuf);
464 return value;
465 }
466
467 static int
468 ep_release (struct inode *inode, struct file *fd)
469 {
470 struct ep_data *data = fd->private_data;
471 int value;
472
473 value = mutex_lock_interruptible(&data->lock);
474 if (value < 0)
475 return value;
476
477 /* clean up if this can be reopened */
478 if (data->state != STATE_EP_UNBOUND) {
479 data->state = STATE_EP_DISABLED;
480 data->desc.bDescriptorType = 0;
481 data->hs_desc.bDescriptorType = 0;
482 usb_ep_disable(data->ep);
483 }
484 mutex_unlock(&data->lock);
485 put_ep (data);
486 return 0;
487 }
488
489 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
490 {
491 struct ep_data *data = fd->private_data;
492 int status;
493
494 if ((status = get_ready_ep (fd->f_flags, data)) < 0)
495 return status;
496
497 spin_lock_irq (&data->dev->lock);
498 if (likely (data->ep != NULL)) {
499 switch (code) {
500 case GADGETFS_FIFO_STATUS:
501 status = usb_ep_fifo_status (data->ep);
502 break;
503 case GADGETFS_FIFO_FLUSH:
504 usb_ep_fifo_flush (data->ep);
505 break;
506 case GADGETFS_CLEAR_HALT:
507 status = usb_ep_clear_halt (data->ep);
508 break;
509 default:
510 status = -ENOTTY;
511 }
512 } else
513 status = -ENODEV;
514 spin_unlock_irq (&data->dev->lock);
515 mutex_unlock(&data->lock);
516 return status;
517 }
518
519 /*----------------------------------------------------------------------*/
520
521 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
522
523 struct kiocb_priv {
524 struct usb_request *req;
525 struct ep_data *epdata;
526 void *buf;
527 const struct iovec *iv;
528 unsigned long nr_segs;
529 unsigned actual;
530 };
531
532 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
533 {
534 struct kiocb_priv *priv = iocb->private;
535 struct ep_data *epdata;
536 int value;
537
538 local_irq_disable();
539 epdata = priv->epdata;
540 // spin_lock(&epdata->dev->lock);
541 kiocbSetCancelled(iocb);
542 if (likely(epdata && epdata->ep && priv->req))
543 value = usb_ep_dequeue (epdata->ep, priv->req);
544 else
545 value = -EINVAL;
546 // spin_unlock(&epdata->dev->lock);
547 local_irq_enable();
548
549 aio_put_req(iocb);
550 return value;
551 }
552
553 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
554 {
555 struct kiocb_priv *priv = iocb->private;
556 ssize_t len, total;
557 void *to_copy;
558 int i;
559
560 /* we "retry" to get the right mm context for this: */
561
562 /* copy stuff into user buffers */
563 total = priv->actual;
564 len = 0;
565 to_copy = priv->buf;
566 for (i=0; i < priv->nr_segs; i++) {
567 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
568
569 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
570 if (len == 0)
571 len = -EFAULT;
572 break;
573 }
574
575 total -= this;
576 len += this;
577 to_copy += this;
578 if (total == 0)
579 break;
580 }
581 kfree(priv->buf);
582 kfree(priv);
583 return len;
584 }
585
586 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
587 {
588 struct kiocb *iocb = req->context;
589 struct kiocb_priv *priv = iocb->private;
590 struct ep_data *epdata = priv->epdata;
591
592 /* lock against disconnect (and ideally, cancel) */
593 spin_lock(&epdata->dev->lock);
594 priv->req = NULL;
595 priv->epdata = NULL;
596
597 /* if this was a write or a read returning no data then we
598 * don't need to copy anything to userspace, so we can
599 * complete the aio request immediately.
600 */
601 if (priv->iv == NULL || unlikely(req->actual == 0)) {
602 kfree(req->buf);
603 kfree(priv);
604 iocb->private = NULL;
605 /* aio_complete() reports bytes-transferred _and_ faults */
606 aio_complete(iocb, req->actual ? req->actual : req->status,
607 req->status);
608 } else {
609 /* retry() won't report both; so we hide some faults */
610 if (unlikely(0 != req->status))
611 DBG(epdata->dev, "%s fault %d len %d\n",
612 ep->name, req->status, req->actual);
613
614 priv->buf = req->buf;
615 priv->actual = req->actual;
616 kick_iocb(iocb);
617 }
618 spin_unlock(&epdata->dev->lock);
619
620 usb_ep_free_request(ep, req);
621 put_ep(epdata);
622 }
623
624 static ssize_t
625 ep_aio_rwtail(
626 struct kiocb *iocb,
627 char *buf,
628 size_t len,
629 struct ep_data *epdata,
630 const struct iovec *iv,
631 unsigned long nr_segs
632 )
633 {
634 struct kiocb_priv *priv;
635 struct usb_request *req;
636 ssize_t value;
637
638 priv = kmalloc(sizeof *priv, GFP_KERNEL);
639 if (!priv) {
640 value = -ENOMEM;
641 fail:
642 kfree(buf);
643 return value;
644 }
645 iocb->private = priv;
646 priv->iv = iv;
647 priv->nr_segs = nr_segs;
648
649 value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
650 if (unlikely(value < 0)) {
651 kfree(priv);
652 goto fail;
653 }
654
655 iocb->ki_cancel = ep_aio_cancel;
656 get_ep(epdata);
657 priv->epdata = epdata;
658 priv->actual = 0;
659
660 /* each kiocb is coupled to one usb_request, but we can't
661 * allocate or submit those if the host disconnected.
662 */
663 spin_lock_irq(&epdata->dev->lock);
664 if (likely(epdata->ep)) {
665 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
666 if (likely(req)) {
667 priv->req = req;
668 req->buf = buf;
669 req->length = len;
670 req->complete = ep_aio_complete;
671 req->context = iocb;
672 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
673 if (unlikely(0 != value))
674 usb_ep_free_request(epdata->ep, req);
675 } else
676 value = -EAGAIN;
677 } else
678 value = -ENODEV;
679 spin_unlock_irq(&epdata->dev->lock);
680
681 mutex_unlock(&epdata->lock);
682
683 if (unlikely(value)) {
684 kfree(priv);
685 put_ep(epdata);
686 } else
687 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
688 return value;
689 }
690
691 static ssize_t
692 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
693 unsigned long nr_segs, loff_t o)
694 {
695 struct ep_data *epdata = iocb->ki_filp->private_data;
696 char *buf;
697
698 if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
699 return -EINVAL;
700
701 buf = kmalloc(iocb->ki_left, GFP_KERNEL);
702 if (unlikely(!buf))
703 return -ENOMEM;
704
705 iocb->ki_retry = ep_aio_read_retry;
706 return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
707 }
708
709 static ssize_t
710 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
711 unsigned long nr_segs, loff_t o)
712 {
713 struct ep_data *epdata = iocb->ki_filp->private_data;
714 char *buf;
715 size_t len = 0;
716 int i = 0;
717
718 if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
719 return -EINVAL;
720
721 buf = kmalloc(iocb->ki_left, GFP_KERNEL);
722 if (unlikely(!buf))
723 return -ENOMEM;
724
725 for (i=0; i < nr_segs; i++) {
726 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
727 iov[i].iov_len) != 0)) {
728 kfree(buf);
729 return -EFAULT;
730 }
731 len += iov[i].iov_len;
732 }
733 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
734 }
735
736 /*----------------------------------------------------------------------*/
737
738 /* used after endpoint configuration */
739 static const struct file_operations ep_io_operations = {
740 .owner = THIS_MODULE,
741 .llseek = no_llseek,
742
743 .read = ep_read,
744 .write = ep_write,
745 .unlocked_ioctl = ep_ioctl,
746 .release = ep_release,
747
748 .aio_read = ep_aio_read,
749 .aio_write = ep_aio_write,
750 };
751
752 /* ENDPOINT INITIALIZATION
753 *
754 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
755 * status = write (fd, descriptors, sizeof descriptors)
756 *
757 * That write establishes the endpoint configuration, configuring
758 * the controller to process bulk, interrupt, or isochronous transfers
759 * at the right maxpacket size, and so on.
760 *
761 * The descriptors are message type 1, identified by a host order u32
762 * at the beginning of what's written. Descriptor order is: full/low
763 * speed descriptor, then optional high speed descriptor.
764 */
765 static ssize_t
766 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
767 {
768 struct ep_data *data = fd->private_data;
769 struct usb_ep *ep;
770 u32 tag;
771 int value, length = len;
772
773 value = mutex_lock_interruptible(&data->lock);
774 if (value < 0)
775 return value;
776
777 if (data->state != STATE_EP_READY) {
778 value = -EL2HLT;
779 goto fail;
780 }
781
782 value = len;
783 if (len < USB_DT_ENDPOINT_SIZE + 4)
784 goto fail0;
785
786 /* we might need to change message format someday */
787 if (copy_from_user (&tag, buf, 4)) {
788 goto fail1;
789 }
790 if (tag != 1) {
791 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
792 goto fail0;
793 }
794 buf += 4;
795 len -= 4;
796
797 /* NOTE: audio endpoint extensions not accepted here;
798 * just don't include the extra bytes.
799 */
800
801 /* full/low speed descriptor, then high speed */
802 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
803 goto fail1;
804 }
805 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
806 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
807 goto fail0;
808 if (len != USB_DT_ENDPOINT_SIZE) {
809 if (len != 2 * USB_DT_ENDPOINT_SIZE)
810 goto fail0;
811 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
812 USB_DT_ENDPOINT_SIZE)) {
813 goto fail1;
814 }
815 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
816 || data->hs_desc.bDescriptorType
817 != USB_DT_ENDPOINT) {
818 DBG(data->dev, "config %s, bad hs length or type\n",
819 data->name);
820 goto fail0;
821 }
822 }
823
824 spin_lock_irq (&data->dev->lock);
825 if (data->dev->state == STATE_DEV_UNBOUND) {
826 value = -ENOENT;
827 goto gone;
828 } else if ((ep = data->ep) == NULL) {
829 value = -ENODEV;
830 goto gone;
831 }
832 switch (data->dev->gadget->speed) {
833 case USB_SPEED_LOW:
834 case USB_SPEED_FULL:
835 value = usb_ep_enable (ep, &data->desc);
836 if (value == 0)
837 data->state = STATE_EP_ENABLED;
838 break;
839 #ifdef CONFIG_USB_GADGET_DUALSPEED
840 case USB_SPEED_HIGH:
841 /* fails if caller didn't provide that descriptor... */
842 value = usb_ep_enable (ep, &data->hs_desc);
843 if (value == 0)
844 data->state = STATE_EP_ENABLED;
845 break;
846 #endif
847 default:
848 DBG(data->dev, "unconnected, %s init abandoned\n",
849 data->name);
850 value = -EINVAL;
851 }
852 if (value == 0) {
853 fd->f_op = &ep_io_operations;
854 value = length;
855 }
856 gone:
857 spin_unlock_irq (&data->dev->lock);
858 if (value < 0) {
859 fail:
860 data->desc.bDescriptorType = 0;
861 data->hs_desc.bDescriptorType = 0;
862 }
863 mutex_unlock(&data->lock);
864 return value;
865 fail0:
866 value = -EINVAL;
867 goto fail;
868 fail1:
869 value = -EFAULT;
870 goto fail;
871 }
872
873 static int
874 ep_open (struct inode *inode, struct file *fd)
875 {
876 struct ep_data *data = inode->i_private;
877 int value = -EBUSY;
878
879 if (mutex_lock_interruptible(&data->lock) != 0)
880 return -EINTR;
881 spin_lock_irq (&data->dev->lock);
882 if (data->dev->state == STATE_DEV_UNBOUND)
883 value = -ENOENT;
884 else if (data->state == STATE_EP_DISABLED) {
885 value = 0;
886 data->state = STATE_EP_READY;
887 get_ep (data);
888 fd->private_data = data;
889 VDEBUG (data->dev, "%s ready\n", data->name);
890 } else
891 DBG (data->dev, "%s state %d\n",
892 data->name, data->state);
893 spin_unlock_irq (&data->dev->lock);
894 mutex_unlock(&data->lock);
895 return value;
896 }
897
898 /* used before endpoint configuration */
899 static const struct file_operations ep_config_operations = {
900 .owner = THIS_MODULE,
901 .llseek = no_llseek,
902
903 .open = ep_open,
904 .write = ep_config,
905 .release = ep_release,
906 };
907
908 /*----------------------------------------------------------------------*/
909
910 /* EP0 IMPLEMENTATION can be partly in userspace.
911 *
912 * Drivers that use this facility receive various events, including
913 * control requests the kernel doesn't handle. Drivers that don't
914 * use this facility may be too simple-minded for real applications.
915 */
916
917 static inline void ep0_readable (struct dev_data *dev)
918 {
919 wake_up (&dev->wait);
920 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
921 }
922
923 static void clean_req (struct usb_ep *ep, struct usb_request *req)
924 {
925 struct dev_data *dev = ep->driver_data;
926
927 if (req->buf != dev->rbuf) {
928 kfree(req->buf);
929 req->buf = dev->rbuf;
930 req->dma = DMA_ADDR_INVALID;
931 }
932 req->complete = epio_complete;
933 dev->setup_out_ready = 0;
934 }
935
936 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
937 {
938 struct dev_data *dev = ep->driver_data;
939 unsigned long flags;
940 int free = 1;
941
942 /* for control OUT, data must still get to userspace */
943 spin_lock_irqsave(&dev->lock, flags);
944 if (!dev->setup_in) {
945 dev->setup_out_error = (req->status != 0);
946 if (!dev->setup_out_error)
947 free = 0;
948 dev->setup_out_ready = 1;
949 ep0_readable (dev);
950 }
951
952 /* clean up as appropriate */
953 if (free && req->buf != &dev->rbuf)
954 clean_req (ep, req);
955 req->complete = epio_complete;
956 spin_unlock_irqrestore(&dev->lock, flags);
957 }
958
959 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
960 {
961 struct dev_data *dev = ep->driver_data;
962
963 if (dev->setup_out_ready) {
964 DBG (dev, "ep0 request busy!\n");
965 return -EBUSY;
966 }
967 if (len > sizeof (dev->rbuf))
968 req->buf = kmalloc(len, GFP_ATOMIC);
969 if (req->buf == NULL) {
970 req->buf = dev->rbuf;
971 return -ENOMEM;
972 }
973 req->complete = ep0_complete;
974 req->length = len;
975 req->zero = 0;
976 return 0;
977 }
978
979 static ssize_t
980 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
981 {
982 struct dev_data *dev = fd->private_data;
983 ssize_t retval;
984 enum ep0_state state;
985
986 spin_lock_irq (&dev->lock);
987
988 /* report fd mode change before acting on it */
989 if (dev->setup_abort) {
990 dev->setup_abort = 0;
991 retval = -EIDRM;
992 goto done;
993 }
994
995 /* control DATA stage */
996 if ((state = dev->state) == STATE_DEV_SETUP) {
997
998 if (dev->setup_in) { /* stall IN */
999 VDEBUG(dev, "ep0in stall\n");
1000 (void) usb_ep_set_halt (dev->gadget->ep0);
1001 retval = -EL2HLT;
1002 dev->state = STATE_DEV_CONNECTED;
1003
1004 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
1005 struct usb_ep *ep = dev->gadget->ep0;
1006 struct usb_request *req = dev->req;
1007
1008 if ((retval = setup_req (ep, req, 0)) == 0)
1009 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1010 dev->state = STATE_DEV_CONNECTED;
1011
1012 /* assume that was SET_CONFIGURATION */
1013 if (dev->current_config) {
1014 unsigned power;
1015
1016 if (gadget_is_dualspeed(dev->gadget)
1017 && (dev->gadget->speed
1018 == USB_SPEED_HIGH))
1019 power = dev->hs_config->bMaxPower;
1020 else
1021 power = dev->config->bMaxPower;
1022 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1023 }
1024
1025 } else { /* collect OUT data */
1026 if ((fd->f_flags & O_NONBLOCK) != 0
1027 && !dev->setup_out_ready) {
1028 retval = -EAGAIN;
1029 goto done;
1030 }
1031 spin_unlock_irq (&dev->lock);
1032 retval = wait_event_interruptible (dev->wait,
1033 dev->setup_out_ready != 0);
1034
1035 /* FIXME state could change from under us */
1036 spin_lock_irq (&dev->lock);
1037 if (retval)
1038 goto done;
1039
1040 if (dev->state != STATE_DEV_SETUP) {
1041 retval = -ECANCELED;
1042 goto done;
1043 }
1044 dev->state = STATE_DEV_CONNECTED;
1045
1046 if (dev->setup_out_error)
1047 retval = -EIO;
1048 else {
1049 len = min (len, (size_t)dev->req->actual);
1050 // FIXME don't call this with the spinlock held ...
1051 if (copy_to_user (buf, dev->req->buf, len))
1052 retval = -EFAULT;
1053 clean_req (dev->gadget->ep0, dev->req);
1054 /* NOTE userspace can't yet choose to stall */
1055 }
1056 }
1057 goto done;
1058 }
1059
1060 /* else normal: return event data */
1061 if (len < sizeof dev->event [0]) {
1062 retval = -EINVAL;
1063 goto done;
1064 }
1065 len -= len % sizeof (struct usb_gadgetfs_event);
1066 dev->usermode_setup = 1;
1067
1068 scan:
1069 /* return queued events right away */
1070 if (dev->ev_next != 0) {
1071 unsigned i, n;
1072
1073 n = len / sizeof (struct usb_gadgetfs_event);
1074 if (dev->ev_next < n)
1075 n = dev->ev_next;
1076
1077 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1078 for (i = 0; i < n; i++) {
1079 if (dev->event [i].type == GADGETFS_SETUP) {
1080 dev->state = STATE_DEV_SETUP;
1081 n = i + 1;
1082 break;
1083 }
1084 }
1085 spin_unlock_irq (&dev->lock);
1086 len = n * sizeof (struct usb_gadgetfs_event);
1087 if (copy_to_user (buf, &dev->event, len))
1088 retval = -EFAULT;
1089 else
1090 retval = len;
1091 if (len > 0) {
1092 /* NOTE this doesn't guard against broken drivers;
1093 * concurrent ep0 readers may lose events.
1094 */
1095 spin_lock_irq (&dev->lock);
1096 if (dev->ev_next > n) {
1097 memmove(&dev->event[0], &dev->event[n],
1098 sizeof (struct usb_gadgetfs_event)
1099 * (dev->ev_next - n));
1100 }
1101 dev->ev_next -= n;
1102 spin_unlock_irq (&dev->lock);
1103 }
1104 return retval;
1105 }
1106 if (fd->f_flags & O_NONBLOCK) {
1107 retval = -EAGAIN;
1108 goto done;
1109 }
1110
1111 switch (state) {
1112 default:
1113 DBG (dev, "fail %s, state %d\n", __func__, state);
1114 retval = -ESRCH;
1115 break;
1116 case STATE_DEV_UNCONNECTED:
1117 case STATE_DEV_CONNECTED:
1118 spin_unlock_irq (&dev->lock);
1119 DBG (dev, "%s wait\n", __func__);
1120
1121 /* wait for events */
1122 retval = wait_event_interruptible (dev->wait,
1123 dev->ev_next != 0);
1124 if (retval < 0)
1125 return retval;
1126 spin_lock_irq (&dev->lock);
1127 goto scan;
1128 }
1129
1130 done:
1131 spin_unlock_irq (&dev->lock);
1132 return retval;
1133 }
1134
1135 static struct usb_gadgetfs_event *
1136 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1137 {
1138 struct usb_gadgetfs_event *event;
1139 unsigned i;
1140
1141 switch (type) {
1142 /* these events purge the queue */
1143 case GADGETFS_DISCONNECT:
1144 if (dev->state == STATE_DEV_SETUP)
1145 dev->setup_abort = 1;
1146 // FALL THROUGH
1147 case GADGETFS_CONNECT:
1148 dev->ev_next = 0;
1149 break;
1150 case GADGETFS_SETUP: /* previous request timed out */
1151 case GADGETFS_SUSPEND: /* same effect */
1152 /* these events can't be repeated */
1153 for (i = 0; i != dev->ev_next; i++) {
1154 if (dev->event [i].type != type)
1155 continue;
1156 DBG(dev, "discard old event[%d] %d\n", i, type);
1157 dev->ev_next--;
1158 if (i == dev->ev_next)
1159 break;
1160 /* indices start at zero, for simplicity */
1161 memmove (&dev->event [i], &dev->event [i + 1],
1162 sizeof (struct usb_gadgetfs_event)
1163 * (dev->ev_next - i));
1164 }
1165 break;
1166 default:
1167 BUG ();
1168 }
1169 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1170 event = &dev->event [dev->ev_next++];
1171 BUG_ON (dev->ev_next > N_EVENT);
1172 memset (event, 0, sizeof *event);
1173 event->type = type;
1174 return event;
1175 }
1176
1177 static ssize_t
1178 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1179 {
1180 struct dev_data *dev = fd->private_data;
1181 ssize_t retval = -ESRCH;
1182
1183 spin_lock_irq (&dev->lock);
1184
1185 /* report fd mode change before acting on it */
1186 if (dev->setup_abort) {
1187 dev->setup_abort = 0;
1188 retval = -EIDRM;
1189
1190 /* data and/or status stage for control request */
1191 } else if (dev->state == STATE_DEV_SETUP) {
1192
1193 /* IN DATA+STATUS caller makes len <= wLength */
1194 if (dev->setup_in) {
1195 retval = setup_req (dev->gadget->ep0, dev->req, len);
1196 if (retval == 0) {
1197 dev->state = STATE_DEV_CONNECTED;
1198 spin_unlock_irq (&dev->lock);
1199 if (copy_from_user (dev->req->buf, buf, len))
1200 retval = -EFAULT;
1201 else {
1202 if (len < dev->setup_wLength)
1203 dev->req->zero = 1;
1204 retval = usb_ep_queue (
1205 dev->gadget->ep0, dev->req,
1206 GFP_KERNEL);
1207 }
1208 if (retval < 0) {
1209 spin_lock_irq (&dev->lock);
1210 clean_req (dev->gadget->ep0, dev->req);
1211 spin_unlock_irq (&dev->lock);
1212 } else
1213 retval = len;
1214
1215 return retval;
1216 }
1217
1218 /* can stall some OUT transfers */
1219 } else if (dev->setup_can_stall) {
1220 VDEBUG(dev, "ep0out stall\n");
1221 (void) usb_ep_set_halt (dev->gadget->ep0);
1222 retval = -EL2HLT;
1223 dev->state = STATE_DEV_CONNECTED;
1224 } else {
1225 DBG(dev, "bogus ep0out stall!\n");
1226 }
1227 } else
1228 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1229
1230 spin_unlock_irq (&dev->lock);
1231 return retval;
1232 }
1233
1234 static int
1235 ep0_fasync (int f, struct file *fd, int on)
1236 {
1237 struct dev_data *dev = fd->private_data;
1238 // caller must F_SETOWN before signal delivery happens
1239 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1240 return fasync_helper (f, fd, on, &dev->fasync);
1241 }
1242
1243 static struct usb_gadget_driver gadgetfs_driver;
1244
1245 static int
1246 dev_release (struct inode *inode, struct file *fd)
1247 {
1248 struct dev_data *dev = fd->private_data;
1249
1250 /* closing ep0 === shutdown all */
1251
1252 usb_gadget_unregister_driver (&gadgetfs_driver);
1253
1254 /* at this point "good" hardware has disconnected the
1255 * device from USB; the host won't see it any more.
1256 * alternatively, all host requests will time out.
1257 */
1258
1259 kfree (dev->buf);
1260 dev->buf = NULL;
1261 put_dev (dev);
1262
1263 /* other endpoints were all decoupled from this device */
1264 spin_lock_irq(&dev->lock);
1265 dev->state = STATE_DEV_DISABLED;
1266 spin_unlock_irq(&dev->lock);
1267 return 0;
1268 }
1269
1270 static unsigned int
1271 ep0_poll (struct file *fd, poll_table *wait)
1272 {
1273 struct dev_data *dev = fd->private_data;
1274 int mask = 0;
1275
1276 poll_wait(fd, &dev->wait, wait);
1277
1278 spin_lock_irq (&dev->lock);
1279
1280 /* report fd mode change before acting on it */
1281 if (dev->setup_abort) {
1282 dev->setup_abort = 0;
1283 mask = POLLHUP;
1284 goto out;
1285 }
1286
1287 if (dev->state == STATE_DEV_SETUP) {
1288 if (dev->setup_in || dev->setup_can_stall)
1289 mask = POLLOUT;
1290 } else {
1291 if (dev->ev_next != 0)
1292 mask = POLLIN;
1293 }
1294 out:
1295 spin_unlock_irq(&dev->lock);
1296 return mask;
1297 }
1298
1299 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1300 {
1301 struct dev_data *dev = fd->private_data;
1302 struct usb_gadget *gadget = dev->gadget;
1303 long ret = -ENOTTY;
1304
1305 if (gadget->ops->ioctl)
1306 ret = gadget->ops->ioctl (gadget, code, value);
1307
1308 return ret;
1309 }
1310
1311 /* used after device configuration */
1312 static const struct file_operations ep0_io_operations = {
1313 .owner = THIS_MODULE,
1314 .llseek = no_llseek,
1315
1316 .read = ep0_read,
1317 .write = ep0_write,
1318 .fasync = ep0_fasync,
1319 .poll = ep0_poll,
1320 .unlocked_ioctl = dev_ioctl,
1321 .release = dev_release,
1322 };
1323
1324 /*----------------------------------------------------------------------*/
1325
1326 /* The in-kernel gadget driver handles most ep0 issues, in particular
1327 * enumerating the single configuration (as provided from user space).
1328 *
1329 * Unrecognized ep0 requests may be handled in user space.
1330 */
1331
1332 #ifdef CONFIG_USB_GADGET_DUALSPEED
1333 static void make_qualifier (struct dev_data *dev)
1334 {
1335 struct usb_qualifier_descriptor qual;
1336 struct usb_device_descriptor *desc;
1337
1338 qual.bLength = sizeof qual;
1339 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1340 qual.bcdUSB = cpu_to_le16 (0x0200);
1341
1342 desc = dev->dev;
1343 qual.bDeviceClass = desc->bDeviceClass;
1344 qual.bDeviceSubClass = desc->bDeviceSubClass;
1345 qual.bDeviceProtocol = desc->bDeviceProtocol;
1346
1347 /* assumes ep0 uses the same value for both speeds ... */
1348 qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1349
1350 qual.bNumConfigurations = 1;
1351 qual.bRESERVED = 0;
1352
1353 memcpy (dev->rbuf, &qual, sizeof qual);
1354 }
1355 #endif
1356
1357 static int
1358 config_buf (struct dev_data *dev, u8 type, unsigned index)
1359 {
1360 int len;
1361 int hs = 0;
1362
1363 /* only one configuration */
1364 if (index > 0)
1365 return -EINVAL;
1366
1367 if (gadget_is_dualspeed(dev->gadget)) {
1368 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1369 if (type == USB_DT_OTHER_SPEED_CONFIG)
1370 hs = !hs;
1371 }
1372 if (hs) {
1373 dev->req->buf = dev->hs_config;
1374 len = le16_to_cpu(dev->hs_config->wTotalLength);
1375 } else {
1376 dev->req->buf = dev->config;
1377 len = le16_to_cpu(dev->config->wTotalLength);
1378 }
1379 ((u8 *)dev->req->buf) [1] = type;
1380 return len;
1381 }
1382
1383 static int
1384 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1385 {
1386 struct dev_data *dev = get_gadget_data (gadget);
1387 struct usb_request *req = dev->req;
1388 int value = -EOPNOTSUPP;
1389 struct usb_gadgetfs_event *event;
1390 u16 w_value = le16_to_cpu(ctrl->wValue);
1391 u16 w_length = le16_to_cpu(ctrl->wLength);
1392
1393 spin_lock (&dev->lock);
1394 dev->setup_abort = 0;
1395 if (dev->state == STATE_DEV_UNCONNECTED) {
1396 if (gadget_is_dualspeed(gadget)
1397 && gadget->speed == USB_SPEED_HIGH
1398 && dev->hs_config == NULL) {
1399 spin_unlock(&dev->lock);
1400 ERROR (dev, "no high speed config??\n");
1401 return -EINVAL;
1402 }
1403
1404 dev->state = STATE_DEV_CONNECTED;
1405 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1406
1407 INFO (dev, "connected\n");
1408 event = next_event (dev, GADGETFS_CONNECT);
1409 event->u.speed = gadget->speed;
1410 ep0_readable (dev);
1411
1412 /* host may have given up waiting for response. we can miss control
1413 * requests handled lower down (device/endpoint status and features);
1414 * then ep0_{read,write} will report the wrong status. controller
1415 * driver will have aborted pending i/o.
1416 */
1417 } else if (dev->state == STATE_DEV_SETUP)
1418 dev->setup_abort = 1;
1419
1420 req->buf = dev->rbuf;
1421 req->dma = DMA_ADDR_INVALID;
1422 req->context = NULL;
1423 value = -EOPNOTSUPP;
1424 switch (ctrl->bRequest) {
1425
1426 case USB_REQ_GET_DESCRIPTOR:
1427 if (ctrl->bRequestType != USB_DIR_IN)
1428 goto unrecognized;
1429 switch (w_value >> 8) {
1430
1431 case USB_DT_DEVICE:
1432 value = min (w_length, (u16) sizeof *dev->dev);
1433 req->buf = dev->dev;
1434 break;
1435 #ifdef CONFIG_USB_GADGET_DUALSPEED
1436 case USB_DT_DEVICE_QUALIFIER:
1437 if (!dev->hs_config)
1438 break;
1439 value = min (w_length, (u16)
1440 sizeof (struct usb_qualifier_descriptor));
1441 make_qualifier (dev);
1442 break;
1443 case USB_DT_OTHER_SPEED_CONFIG:
1444 // FALLTHROUGH
1445 #endif
1446 case USB_DT_CONFIG:
1447 value = config_buf (dev,
1448 w_value >> 8,
1449 w_value & 0xff);
1450 if (value >= 0)
1451 value = min (w_length, (u16) value);
1452 break;
1453 case USB_DT_STRING:
1454 goto unrecognized;
1455
1456 default: // all others are errors
1457 break;
1458 }
1459 break;
1460
1461 /* currently one config, two speeds */
1462 case USB_REQ_SET_CONFIGURATION:
1463 if (ctrl->bRequestType != 0)
1464 goto unrecognized;
1465 if (0 == (u8) w_value) {
1466 value = 0;
1467 dev->current_config = 0;
1468 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1469 // user mode expected to disable endpoints
1470 } else {
1471 u8 config, power;
1472
1473 if (gadget_is_dualspeed(gadget)
1474 && gadget->speed == USB_SPEED_HIGH) {
1475 config = dev->hs_config->bConfigurationValue;
1476 power = dev->hs_config->bMaxPower;
1477 } else {
1478 config = dev->config->bConfigurationValue;
1479 power = dev->config->bMaxPower;
1480 }
1481
1482 if (config == (u8) w_value) {
1483 value = 0;
1484 dev->current_config = config;
1485 usb_gadget_vbus_draw(gadget, 2 * power);
1486 }
1487 }
1488
1489 /* report SET_CONFIGURATION like any other control request,
1490 * except that usermode may not stall this. the next
1491 * request mustn't be allowed start until this finishes:
1492 * endpoints and threads set up, etc.
1493 *
1494 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1495 * has bad/racey automagic that prevents synchronizing here.
1496 * even kernel mode drivers often miss them.
1497 */
1498 if (value == 0) {
1499 INFO (dev, "configuration #%d\n", dev->current_config);
1500 if (dev->usermode_setup) {
1501 dev->setup_can_stall = 0;
1502 goto delegate;
1503 }
1504 }
1505 break;
1506
1507 #ifndef CONFIG_USB_GADGET_PXA25X
1508 /* PXA automagically handles this request too */
1509 case USB_REQ_GET_CONFIGURATION:
1510 if (ctrl->bRequestType != 0x80)
1511 goto unrecognized;
1512 *(u8 *)req->buf = dev->current_config;
1513 value = min (w_length, (u16) 1);
1514 break;
1515 #endif
1516
1517 default:
1518 unrecognized:
1519 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1520 dev->usermode_setup ? "delegate" : "fail",
1521 ctrl->bRequestType, ctrl->bRequest,
1522 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1523
1524 /* if there's an ep0 reader, don't stall */
1525 if (dev->usermode_setup) {
1526 dev->setup_can_stall = 1;
1527 delegate:
1528 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1529 ? 1 : 0;
1530 dev->setup_wLength = w_length;
1531 dev->setup_out_ready = 0;
1532 dev->setup_out_error = 0;
1533 value = 0;
1534
1535 /* read DATA stage for OUT right away */
1536 if (unlikely (!dev->setup_in && w_length)) {
1537 value = setup_req (gadget->ep0, dev->req,
1538 w_length);
1539 if (value < 0)
1540 break;
1541 value = usb_ep_queue (gadget->ep0, dev->req,
1542 GFP_ATOMIC);
1543 if (value < 0) {
1544 clean_req (gadget->ep0, dev->req);
1545 break;
1546 }
1547
1548 /* we can't currently stall these */
1549 dev->setup_can_stall = 0;
1550 }
1551
1552 /* state changes when reader collects event */
1553 event = next_event (dev, GADGETFS_SETUP);
1554 event->u.setup = *ctrl;
1555 ep0_readable (dev);
1556 spin_unlock (&dev->lock);
1557 return 0;
1558 }
1559 }
1560
1561 /* proceed with data transfer and status phases? */
1562 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1563 req->length = value;
1564 req->zero = value < w_length;
1565 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1566 if (value < 0) {
1567 DBG (dev, "ep_queue --> %d\n", value);
1568 req->status = 0;
1569 }
1570 }
1571
1572 /* device stalls when value < 0 */
1573 spin_unlock (&dev->lock);
1574 return value;
1575 }
1576
1577 static void destroy_ep_files (struct dev_data *dev)
1578 {
1579 struct list_head *entry, *tmp;
1580
1581 DBG (dev, "%s %d\n", __func__, dev->state);
1582
1583 /* dev->state must prevent interference */
1584 restart:
1585 spin_lock_irq (&dev->lock);
1586 list_for_each_safe (entry, tmp, &dev->epfiles) {
1587 struct ep_data *ep;
1588 struct inode *parent;
1589 struct dentry *dentry;
1590
1591 /* break link to FS */
1592 ep = list_entry (entry, struct ep_data, epfiles);
1593 list_del_init (&ep->epfiles);
1594 dentry = ep->dentry;
1595 ep->dentry = NULL;
1596 parent = dentry->d_parent->d_inode;
1597
1598 /* break link to controller */
1599 if (ep->state == STATE_EP_ENABLED)
1600 (void) usb_ep_disable (ep->ep);
1601 ep->state = STATE_EP_UNBOUND;
1602 usb_ep_free_request (ep->ep, ep->req);
1603 ep->ep = NULL;
1604 wake_up (&ep->wait);
1605 put_ep (ep);
1606
1607 spin_unlock_irq (&dev->lock);
1608
1609 /* break link to dcache */
1610 mutex_lock (&parent->i_mutex);
1611 d_delete (dentry);
1612 dput (dentry);
1613 mutex_unlock (&parent->i_mutex);
1614
1615 /* fds may still be open */
1616 goto restart;
1617 }
1618 spin_unlock_irq (&dev->lock);
1619 }
1620
1621
1622 static struct inode *
1623 gadgetfs_create_file (struct super_block *sb, char const *name,
1624 void *data, const struct file_operations *fops,
1625 struct dentry **dentry_p);
1626
1627 static int activate_ep_files (struct dev_data *dev)
1628 {
1629 struct usb_ep *ep;
1630 struct ep_data *data;
1631
1632 gadget_for_each_ep (ep, dev->gadget) {
1633
1634 data = kzalloc(sizeof(*data), GFP_KERNEL);
1635 if (!data)
1636 goto enomem0;
1637 data->state = STATE_EP_DISABLED;
1638 mutex_init(&data->lock);
1639 init_waitqueue_head (&data->wait);
1640
1641 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1642 atomic_set (&data->count, 1);
1643 data->dev = dev;
1644 get_dev (dev);
1645
1646 data->ep = ep;
1647 ep->driver_data = data;
1648
1649 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1650 if (!data->req)
1651 goto enomem1;
1652
1653 data->inode = gadgetfs_create_file (dev->sb, data->name,
1654 data, &ep_config_operations,
1655 &data->dentry);
1656 if (!data->inode)
1657 goto enomem2;
1658 list_add_tail (&data->epfiles, &dev->epfiles);
1659 }
1660 return 0;
1661
1662 enomem2:
1663 usb_ep_free_request (ep, data->req);
1664 enomem1:
1665 put_dev (dev);
1666 kfree (data);
1667 enomem0:
1668 DBG (dev, "%s enomem\n", __func__);
1669 destroy_ep_files (dev);
1670 return -ENOMEM;
1671 }
1672
1673 static void
1674 gadgetfs_unbind (struct usb_gadget *gadget)
1675 {
1676 struct dev_data *dev = get_gadget_data (gadget);
1677
1678 DBG (dev, "%s\n", __func__);
1679
1680 spin_lock_irq (&dev->lock);
1681 dev->state = STATE_DEV_UNBOUND;
1682 spin_unlock_irq (&dev->lock);
1683
1684 destroy_ep_files (dev);
1685 gadget->ep0->driver_data = NULL;
1686 set_gadget_data (gadget, NULL);
1687
1688 /* we've already been disconnected ... no i/o is active */
1689 if (dev->req)
1690 usb_ep_free_request (gadget->ep0, dev->req);
1691 DBG (dev, "%s done\n", __func__);
1692 put_dev (dev);
1693 }
1694
1695 static struct dev_data *the_device;
1696
1697 static int
1698 gadgetfs_bind (struct usb_gadget *gadget)
1699 {
1700 struct dev_data *dev = the_device;
1701
1702 if (!dev)
1703 return -ESRCH;
1704 if (0 != strcmp (CHIP, gadget->name)) {
1705 pr_err("%s expected %s controller not %s\n",
1706 shortname, CHIP, gadget->name);
1707 return -ENODEV;
1708 }
1709
1710 set_gadget_data (gadget, dev);
1711 dev->gadget = gadget;
1712 gadget->ep0->driver_data = dev;
1713 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1714
1715 /* preallocate control response and buffer */
1716 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1717 if (!dev->req)
1718 goto enomem;
1719 dev->req->context = NULL;
1720 dev->req->complete = epio_complete;
1721
1722 if (activate_ep_files (dev) < 0)
1723 goto enomem;
1724
1725 INFO (dev, "bound to %s driver\n", gadget->name);
1726 spin_lock_irq(&dev->lock);
1727 dev->state = STATE_DEV_UNCONNECTED;
1728 spin_unlock_irq(&dev->lock);
1729 get_dev (dev);
1730 return 0;
1731
1732 enomem:
1733 gadgetfs_unbind (gadget);
1734 return -ENOMEM;
1735 }
1736
1737 static void
1738 gadgetfs_disconnect (struct usb_gadget *gadget)
1739 {
1740 struct dev_data *dev = get_gadget_data (gadget);
1741
1742 spin_lock (&dev->lock);
1743 if (dev->state == STATE_DEV_UNCONNECTED)
1744 goto exit;
1745 dev->state = STATE_DEV_UNCONNECTED;
1746
1747 INFO (dev, "disconnected\n");
1748 next_event (dev, GADGETFS_DISCONNECT);
1749 ep0_readable (dev);
1750 exit:
1751 spin_unlock (&dev->lock);
1752 }
1753
1754 static void
1755 gadgetfs_suspend (struct usb_gadget *gadget)
1756 {
1757 struct dev_data *dev = get_gadget_data (gadget);
1758
1759 INFO (dev, "suspended from state %d\n", dev->state);
1760 spin_lock (&dev->lock);
1761 switch (dev->state) {
1762 case STATE_DEV_SETUP: // VERY odd... host died??
1763 case STATE_DEV_CONNECTED:
1764 case STATE_DEV_UNCONNECTED:
1765 next_event (dev, GADGETFS_SUSPEND);
1766 ep0_readable (dev);
1767 /* FALLTHROUGH */
1768 default:
1769 break;
1770 }
1771 spin_unlock (&dev->lock);
1772 }
1773
1774 static struct usb_gadget_driver gadgetfs_driver = {
1775 #ifdef CONFIG_USB_GADGET_DUALSPEED
1776 .speed = USB_SPEED_HIGH,
1777 #else
1778 .speed = USB_SPEED_FULL,
1779 #endif
1780 .function = (char *) driver_desc,
1781 .unbind = gadgetfs_unbind,
1782 .setup = gadgetfs_setup,
1783 .disconnect = gadgetfs_disconnect,
1784 .suspend = gadgetfs_suspend,
1785
1786 .driver = {
1787 .name = (char *) shortname,
1788 },
1789 };
1790
1791 /*----------------------------------------------------------------------*/
1792
1793 static void gadgetfs_nop(struct usb_gadget *arg) { }
1794
1795 static int gadgetfs_probe (struct usb_gadget *gadget)
1796 {
1797 CHIP = gadget->name;
1798 return -EISNAM;
1799 }
1800
1801 static struct usb_gadget_driver probe_driver = {
1802 .speed = USB_SPEED_HIGH,
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 = memdup_user(buf, length);
1870 if (IS_ERR(kbuf))
1871 return PTR_ERR(kbuf);
1872
1873 spin_lock_irq (&dev->lock);
1874 value = -EINVAL;
1875 if (dev->buf)
1876 goto fail;
1877 dev->buf = kbuf;
1878
1879 /* full or low speed config */
1880 dev->config = (void *) kbuf;
1881 total = le16_to_cpu(dev->config->wTotalLength);
1882 if (!is_valid_config (dev->config) || total >= length)
1883 goto fail;
1884 kbuf += total;
1885 length -= total;
1886
1887 /* optional high speed config */
1888 if (kbuf [1] == USB_DT_CONFIG) {
1889 dev->hs_config = (void *) kbuf;
1890 total = le16_to_cpu(dev->hs_config->wTotalLength);
1891 if (!is_valid_config (dev->hs_config) || total >= length)
1892 goto fail;
1893 kbuf += total;
1894 length -= total;
1895 }
1896
1897 /* could support multiple configs, using another encoding! */
1898
1899 /* device descriptor (tweaked for paranoia) */
1900 if (length != USB_DT_DEVICE_SIZE)
1901 goto fail;
1902 dev->dev = (void *)kbuf;
1903 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1904 || dev->dev->bDescriptorType != USB_DT_DEVICE
1905 || dev->dev->bNumConfigurations != 1)
1906 goto fail;
1907 dev->dev->bNumConfigurations = 1;
1908 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1909
1910 /* triggers gadgetfs_bind(); then we can enumerate. */
1911 spin_unlock_irq (&dev->lock);
1912 value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1913 if (value != 0) {
1914 kfree (dev->buf);
1915 dev->buf = NULL;
1916 } else {
1917 /* at this point "good" hardware has for the first time
1918 * let the USB the host see us. alternatively, if users
1919 * unplug/replug that will clear all the error state.
1920 *
1921 * note: everything running before here was guaranteed
1922 * to choke driver model style diagnostics. from here
1923 * on, they can work ... except in cleanup paths that
1924 * kick in after the ep0 descriptor is closed.
1925 */
1926 fd->f_op = &ep0_io_operations;
1927 value = len;
1928 }
1929 return value;
1930
1931 fail:
1932 spin_unlock_irq (&dev->lock);
1933 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1934 kfree (dev->buf);
1935 dev->buf = NULL;
1936 return value;
1937 }
1938
1939 static int
1940 dev_open (struct inode *inode, struct file *fd)
1941 {
1942 struct dev_data *dev = inode->i_private;
1943 int value = -EBUSY;
1944
1945 spin_lock_irq(&dev->lock);
1946 if (dev->state == STATE_DEV_DISABLED) {
1947 dev->ev_next = 0;
1948 dev->state = STATE_DEV_OPENED;
1949 fd->private_data = dev;
1950 get_dev (dev);
1951 value = 0;
1952 }
1953 spin_unlock_irq(&dev->lock);
1954 return value;
1955 }
1956
1957 static const struct file_operations dev_init_operations = {
1958 .owner = THIS_MODULE,
1959 .llseek = no_llseek,
1960
1961 .open = dev_open,
1962 .write = dev_config,
1963 .fasync = ep0_fasync,
1964 .unlocked_ioctl = dev_ioctl,
1965 .release = dev_release,
1966 };
1967
1968 /*----------------------------------------------------------------------*/
1969
1970 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1971 *
1972 * Mounting the filesystem creates a controller file, used first for
1973 * device configuration then later for event monitoring.
1974 */
1975
1976
1977 /* FIXME PAM etc could set this security policy without mount options
1978 * if epfiles inherited ownership and permissons from ep0 ...
1979 */
1980
1981 static unsigned default_uid;
1982 static unsigned default_gid;
1983 static unsigned default_perm = S_IRUSR | S_IWUSR;
1984
1985 module_param (default_uid, uint, 0644);
1986 module_param (default_gid, uint, 0644);
1987 module_param (default_perm, uint, 0644);
1988
1989
1990 static struct inode *
1991 gadgetfs_make_inode (struct super_block *sb,
1992 void *data, const struct file_operations *fops,
1993 int mode)
1994 {
1995 struct inode *inode = new_inode (sb);
1996
1997 if (inode) {
1998 inode->i_ino = get_next_ino();
1999 inode->i_mode = mode;
2000 inode->i_uid = default_uid;
2001 inode->i_gid = default_gid;
2002 inode->i_atime = inode->i_mtime = inode->i_ctime
2003 = CURRENT_TIME;
2004 inode->i_private = data;
2005 inode->i_fop = fops;
2006 }
2007 return inode;
2008 }
2009
2010 /* creates in fs root directory, so non-renamable and non-linkable.
2011 * so inode and dentry are paired, until device reconfig.
2012 */
2013 static struct inode *
2014 gadgetfs_create_file (struct super_block *sb, char const *name,
2015 void *data, const struct file_operations *fops,
2016 struct dentry **dentry_p)
2017 {
2018 struct dentry *dentry;
2019 struct inode *inode;
2020
2021 dentry = d_alloc_name(sb->s_root, name);
2022 if (!dentry)
2023 return NULL;
2024
2025 inode = gadgetfs_make_inode (sb, data, fops,
2026 S_IFREG | (default_perm & S_IRWXUGO));
2027 if (!inode) {
2028 dput(dentry);
2029 return NULL;
2030 }
2031 d_add (dentry, inode);
2032 *dentry_p = dentry;
2033 return inode;
2034 }
2035
2036 static const struct super_operations gadget_fs_operations = {
2037 .statfs = simple_statfs,
2038 .drop_inode = generic_delete_inode,
2039 };
2040
2041 static int
2042 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2043 {
2044 struct inode *inode;
2045 struct dentry *d;
2046 struct dev_data *dev;
2047
2048 if (the_device)
2049 return -ESRCH;
2050
2051 /* fake probe to determine $CHIP */
2052 (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2053 if (!CHIP)
2054 return -ENODEV;
2055
2056 /* superblock */
2057 sb->s_blocksize = PAGE_CACHE_SIZE;
2058 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2059 sb->s_magic = GADGETFS_MAGIC;
2060 sb->s_op = &gadget_fs_operations;
2061 sb->s_time_gran = 1;
2062
2063 /* root inode */
2064 inode = gadgetfs_make_inode (sb,
2065 NULL, &simple_dir_operations,
2066 S_IFDIR | S_IRUGO | S_IXUGO);
2067 if (!inode)
2068 goto enomem0;
2069 inode->i_op = &simple_dir_inode_operations;
2070 if (!(d = d_alloc_root (inode)))
2071 goto enomem1;
2072 sb->s_root = d;
2073
2074 /* the ep0 file is named after the controller we expect;
2075 * user mode code can use it for sanity checks, like we do.
2076 */
2077 dev = dev_new ();
2078 if (!dev)
2079 goto enomem2;
2080
2081 dev->sb = sb;
2082 if (!gadgetfs_create_file (sb, CHIP,
2083 dev, &dev_init_operations,
2084 &dev->dentry))
2085 goto enomem3;
2086
2087 /* other endpoint files are available after hardware setup,
2088 * from binding to a controller.
2089 */
2090 the_device = dev;
2091 return 0;
2092
2093 enomem3:
2094 put_dev (dev);
2095 enomem2:
2096 dput (d);
2097 enomem1:
2098 iput (inode);
2099 enomem0:
2100 return -ENOMEM;
2101 }
2102
2103 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2104 static struct dentry *
2105 gadgetfs_mount (struct file_system_type *t, int flags,
2106 const char *path, void *opts)
2107 {
2108 return mount_single (t, flags, opts, gadgetfs_fill_super);
2109 }
2110
2111 static void
2112 gadgetfs_kill_sb (struct super_block *sb)
2113 {
2114 kill_litter_super (sb);
2115 if (the_device) {
2116 put_dev (the_device);
2117 the_device = NULL;
2118 }
2119 }
2120
2121 /*----------------------------------------------------------------------*/
2122
2123 static struct file_system_type gadgetfs_type = {
2124 .owner = THIS_MODULE,
2125 .name = shortname,
2126 .mount = gadgetfs_mount,
2127 .kill_sb = gadgetfs_kill_sb,
2128 };
2129
2130 /*----------------------------------------------------------------------*/
2131
2132 static int __init init (void)
2133 {
2134 int status;
2135
2136 status = register_filesystem (&gadgetfs_type);
2137 if (status == 0)
2138 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2139 shortname, driver_desc);
2140 return status;
2141 }
2142 module_init (init);
2143
2144 static void __exit cleanup (void)
2145 {
2146 pr_debug ("unregister %s\n", shortname);
2147 unregister_filesystem (&gadgetfs_type);
2148 }
2149 module_exit (cleanup);
2150
Linux kernel - Deliverables
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