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gadgetfs: saner API for gadgetfs_create_file()
[deliverable/linux.git] / drivers / usb / gadget / legacy / 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
13
14 /* #define VERBOSE_DEBUG */
15
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/fs.h>
19 #include <linux/pagemap.h>
20 #include <linux/uts.h>
21 #include <linux/wait.h>
22 #include <linux/compiler.h>
23 #include <asm/uaccess.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/poll.h>
27 #include <linux/mmu_context.h>
28 #include <linux/aio.h>
29
30 #include <linux/device.h>
31 #include <linux/moduleparam.h>
32
33 #include <linux/usb/gadgetfs.h>
34 #include <linux/usb/gadget.h>
35
36
37 /*
38 * The gadgetfs API maps each endpoint to a file descriptor so that you
39 * can use standard synchronous read/write calls for I/O. There's some
40 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
41 * drivers show how this works in practice. You can also use AIO to
42 * eliminate I/O gaps between requests, to help when streaming data.
43 *
44 * Key parts that must be USB-specific are protocols defining how the
45 * read/write operations relate to the hardware state machines. There
46 * are two types of files. One type is for the device, implementing ep0.
47 * The other type is for each IN or OUT endpoint. In both cases, the
48 * user mode driver must configure the hardware before using it.
49 *
50 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
51 * (by writing configuration and device descriptors). Afterwards it
52 * may serve as a source of device events, used to handle all control
53 * requests other than basic enumeration.
54 *
55 * - Then, after a SET_CONFIGURATION control request, ep_config() is
56 * called when each /dev/gadget/ep* file is configured (by writing
57 * endpoint descriptors). Afterwards these files are used to write()
58 * IN data or to read() OUT data. To halt the endpoint, a "wrong
59 * direction" request is issued (like reading an IN endpoint).
60 *
61 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
62 * not possible on all hardware. For example, precise fault handling with
63 * respect to data left in endpoint fifos after aborted operations; or
64 * selective clearing of endpoint halts, to implement SET_INTERFACE.
65 */
66
67 #define DRIVER_DESC "USB Gadget filesystem"
68 #define DRIVER_VERSION "24 Aug 2004"
69
70 static const char driver_desc [] = DRIVER_DESC;
71 static const char shortname [] = "gadgetfs";
72
73 MODULE_DESCRIPTION (DRIVER_DESC);
74 MODULE_AUTHOR ("David Brownell");
75 MODULE_LICENSE ("GPL");
76
77
78 /*----------------------------------------------------------------------*/
79
80 #define GADGETFS_MAGIC 0xaee71ee7
81
82 /* /dev/gadget/$CHIP represents ep0 and the whole device */
83 enum ep0_state {
84 /* DISBLED is the initial state.
85 */
86 STATE_DEV_DISABLED = 0,
87
88 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
89 * ep0/device i/o modes and binding to the controller. Driver
90 * must always write descriptors to initialize the device, then
91 * the device becomes UNCONNECTED until enumeration.
92 */
93 STATE_DEV_OPENED,
94
95 /* From then on, ep0 fd is in either of two basic modes:
96 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
97 * - SETUP: read/write will transfer control data and succeed;
98 * or if "wrong direction", performs protocol stall
99 */
100 STATE_DEV_UNCONNECTED,
101 STATE_DEV_CONNECTED,
102 STATE_DEV_SETUP,
103
104 /* UNBOUND means the driver closed ep0, so the device won't be
105 * accessible again (DEV_DISABLED) until all fds are closed.
106 */
107 STATE_DEV_UNBOUND,
108 };
109
110 /* enough for the whole queue: most events invalidate others */
111 #define N_EVENT 5
112
113 struct dev_data {
114 spinlock_t lock;
115 atomic_t count;
116 enum ep0_state state; /* P: lock */
117 struct usb_gadgetfs_event event [N_EVENT];
118 unsigned ev_next;
119 struct fasync_struct *fasync;
120 u8 current_config;
121
122 /* drivers reading ep0 MUST handle control requests (SETUP)
123 * reported that way; else the host will time out.
124 */
125 unsigned usermode_setup : 1,
126 setup_in : 1,
127 setup_can_stall : 1,
128 setup_out_ready : 1,
129 setup_out_error : 1,
130 setup_abort : 1;
131 unsigned setup_wLength;
132
133 /* the rest is basically write-once */
134 struct usb_config_descriptor *config, *hs_config;
135 struct usb_device_descriptor *dev;
136 struct usb_request *req;
137 struct usb_gadget *gadget;
138 struct list_head epfiles;
139 void *buf;
140 wait_queue_head_t wait;
141 struct super_block *sb;
142 struct dentry *dentry;
143
144 /* except this scratch i/o buffer for ep0 */
145 u8 rbuf [256];
146 };
147
148 static inline void get_dev (struct dev_data *data)
149 {
150 atomic_inc (&data->count);
151 }
152
153 static void put_dev (struct dev_data *data)
154 {
155 if (likely (!atomic_dec_and_test (&data->count)))
156 return;
157 /* needs no more cleanup */
158 BUG_ON (waitqueue_active (&data->wait));
159 kfree (data);
160 }
161
162 static struct dev_data *dev_new (void)
163 {
164 struct dev_data *dev;
165
166 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
167 if (!dev)
168 return NULL;
169 dev->state = STATE_DEV_DISABLED;
170 atomic_set (&dev->count, 1);
171 spin_lock_init (&dev->lock);
172 INIT_LIST_HEAD (&dev->epfiles);
173 init_waitqueue_head (&dev->wait);
174 return dev;
175 }
176
177 /*----------------------------------------------------------------------*/
178
179 /* other /dev/gadget/$ENDPOINT files represent endpoints */
180 enum ep_state {
181 STATE_EP_DISABLED = 0,
182 STATE_EP_READY,
183 STATE_EP_ENABLED,
184 STATE_EP_UNBOUND,
185 };
186
187 struct ep_data {
188 struct mutex lock;
189 enum ep_state state;
190 atomic_t count;
191 struct dev_data *dev;
192 /* must hold dev->lock before accessing ep or req */
193 struct usb_ep *ep;
194 struct usb_request *req;
195 ssize_t status;
196 char name [16];
197 struct usb_endpoint_descriptor desc, hs_desc;
198 struct list_head epfiles;
199 wait_queue_head_t wait;
200 struct dentry *dentry;
201 };
202
203 static inline void get_ep (struct ep_data *data)
204 {
205 atomic_inc (&data->count);
206 }
207
208 static void put_ep (struct ep_data *data)
209 {
210 if (likely (!atomic_dec_and_test (&data->count)))
211 return;
212 put_dev (data->dev);
213 /* needs no more cleanup */
214 BUG_ON (!list_empty (&data->epfiles));
215 BUG_ON (waitqueue_active (&data->wait));
216 kfree (data);
217 }
218
219 /*----------------------------------------------------------------------*/
220
221 /* most "how to use the hardware" policy choices are in userspace:
222 * mapping endpoint roles (which the driver needs) to the capabilities
223 * which the usb controller has. most of those capabilities are exposed
224 * implicitly, starting with the driver name and then endpoint names.
225 */
226
227 static const char *CHIP;
228
229 /*----------------------------------------------------------------------*/
230
231 /* NOTE: don't use dev_printk calls before binding to the gadget
232 * at the end of ep0 configuration, or after unbind.
233 */
234
235 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
236 #define xprintk(d,level,fmt,args...) \
237 printk(level "%s: " fmt , shortname , ## args)
238
239 #ifdef DEBUG
240 #define DBG(dev,fmt,args...) \
241 xprintk(dev , KERN_DEBUG , fmt , ## args)
242 #else
243 #define DBG(dev,fmt,args...) \
244 do { } while (0)
245 #endif /* DEBUG */
246
247 #ifdef VERBOSE_DEBUG
248 #define VDEBUG DBG
249 #else
250 #define VDEBUG(dev,fmt,args...) \
251 do { } while (0)
252 #endif /* DEBUG */
253
254 #define ERROR(dev,fmt,args...) \
255 xprintk(dev , KERN_ERR , fmt , ## args)
256 #define INFO(dev,fmt,args...) \
257 xprintk(dev , KERN_INFO , fmt , ## args)
258
259
260 /*----------------------------------------------------------------------*/
261
262 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
263 *
264 * After opening, configure non-control endpoints. Then use normal
265 * stream read() and write() requests; and maybe ioctl() to get more
266 * precise FIFO status when recovering from cancellation.
267 */
268
269 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
270 {
271 struct ep_data *epdata = ep->driver_data;
272
273 if (!req->context)
274 return;
275 if (req->status)
276 epdata->status = req->status;
277 else
278 epdata->status = req->actual;
279 complete ((struct completion *)req->context);
280 }
281
282 /* tasklock endpoint, returning when it's connected.
283 * still need dev->lock to use epdata->ep.
284 */
285 static int
286 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
287 {
288 int val;
289
290 if (f_flags & O_NONBLOCK) {
291 if (!mutex_trylock(&epdata->lock))
292 goto nonblock;
293 if (epdata->state != STATE_EP_ENABLED) {
294 mutex_unlock(&epdata->lock);
295 nonblock:
296 val = -EAGAIN;
297 } else
298 val = 0;
299 return val;
300 }
301
302 val = mutex_lock_interruptible(&epdata->lock);
303 if (val < 0)
304 return val;
305
306 switch (epdata->state) {
307 case STATE_EP_ENABLED:
308 break;
309 // case STATE_EP_DISABLED: /* "can't happen" */
310 // case STATE_EP_READY: /* "can't happen" */
311 default: /* error! */
312 pr_debug ("%s: ep %p not available, state %d\n",
313 shortname, epdata, epdata->state);
314 // FALLTHROUGH
315 case STATE_EP_UNBOUND: /* clean disconnect */
316 val = -ENODEV;
317 mutex_unlock(&epdata->lock);
318 }
319 return val;
320 }
321
322 static ssize_t
323 ep_io (struct ep_data *epdata, void *buf, unsigned len)
324 {
325 DECLARE_COMPLETION_ONSTACK (done);
326 int value;
327
328 spin_lock_irq (&epdata->dev->lock);
329 if (likely (epdata->ep != NULL)) {
330 struct usb_request *req = epdata->req;
331
332 req->context = &done;
333 req->complete = epio_complete;
334 req->buf = buf;
335 req->length = len;
336 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
337 } else
338 value = -ENODEV;
339 spin_unlock_irq (&epdata->dev->lock);
340
341 if (likely (value == 0)) {
342 value = wait_event_interruptible (done.wait, done.done);
343 if (value != 0) {
344 spin_lock_irq (&epdata->dev->lock);
345 if (likely (epdata->ep != NULL)) {
346 DBG (epdata->dev, "%s i/o interrupted\n",
347 epdata->name);
348 usb_ep_dequeue (epdata->ep, epdata->req);
349 spin_unlock_irq (&epdata->dev->lock);
350
351 wait_event (done.wait, done.done);
352 if (epdata->status == -ECONNRESET)
353 epdata->status = -EINTR;
354 } else {
355 spin_unlock_irq (&epdata->dev->lock);
356
357 DBG (epdata->dev, "endpoint gone\n");
358 epdata->status = -ENODEV;
359 }
360 }
361 return epdata->status;
362 }
363 return value;
364 }
365
366
367 /* handle a synchronous OUT bulk/intr/iso transfer */
368 static ssize_t
369 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
370 {
371 struct ep_data *data = fd->private_data;
372 void *kbuf;
373 ssize_t value;
374
375 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
376 return value;
377
378 /* halt any endpoint by doing a "wrong direction" i/o call */
379 if (usb_endpoint_dir_in(&data->desc)) {
380 if (usb_endpoint_xfer_isoc(&data->desc)) {
381 mutex_unlock(&data->lock);
382 return -EINVAL;
383 }
384 DBG (data->dev, "%s halt\n", data->name);
385 spin_lock_irq (&data->dev->lock);
386 if (likely (data->ep != NULL))
387 usb_ep_set_halt (data->ep);
388 spin_unlock_irq (&data->dev->lock);
389 mutex_unlock(&data->lock);
390 return -EBADMSG;
391 }
392
393 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
394
395 value = -ENOMEM;
396 kbuf = kmalloc (len, GFP_KERNEL);
397 if (unlikely (!kbuf))
398 goto free1;
399
400 value = ep_io (data, kbuf, len);
401 VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
402 data->name, len, (int) value);
403 if (value >= 0 && copy_to_user (buf, kbuf, value))
404 value = -EFAULT;
405
406 free1:
407 mutex_unlock(&data->lock);
408 kfree (kbuf);
409 return value;
410 }
411
412 /* handle a synchronous IN bulk/intr/iso transfer */
413 static ssize_t
414 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
415 {
416 struct ep_data *data = fd->private_data;
417 void *kbuf;
418 ssize_t value;
419
420 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
421 return value;
422
423 /* halt any endpoint by doing a "wrong direction" i/o call */
424 if (!usb_endpoint_dir_in(&data->desc)) {
425 if (usb_endpoint_xfer_isoc(&data->desc)) {
426 mutex_unlock(&data->lock);
427 return -EINVAL;
428 }
429 DBG (data->dev, "%s halt\n", data->name);
430 spin_lock_irq (&data->dev->lock);
431 if (likely (data->ep != NULL))
432 usb_ep_set_halt (data->ep);
433 spin_unlock_irq (&data->dev->lock);
434 mutex_unlock(&data->lock);
435 return -EBADMSG;
436 }
437
438 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
439
440 value = -ENOMEM;
441 kbuf = memdup_user(buf, len);
442 if (IS_ERR(kbuf)) {
443 value = PTR_ERR(kbuf);
444 goto free1;
445 }
446
447 value = ep_io (data, kbuf, len);
448 VDEBUG (data->dev, "%s write %zu IN, status %d\n",
449 data->name, len, (int) value);
450 free1:
451 mutex_unlock(&data->lock);
452 return value;
453 }
454
455 static int
456 ep_release (struct inode *inode, struct file *fd)
457 {
458 struct ep_data *data = fd->private_data;
459 int value;
460
461 value = mutex_lock_interruptible(&data->lock);
462 if (value < 0)
463 return value;
464
465 /* clean up if this can be reopened */
466 if (data->state != STATE_EP_UNBOUND) {
467 data->state = STATE_EP_DISABLED;
468 data->desc.bDescriptorType = 0;
469 data->hs_desc.bDescriptorType = 0;
470 usb_ep_disable(data->ep);
471 }
472 mutex_unlock(&data->lock);
473 put_ep (data);
474 return 0;
475 }
476
477 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
478 {
479 struct ep_data *data = fd->private_data;
480 int status;
481
482 if ((status = get_ready_ep (fd->f_flags, data)) < 0)
483 return status;
484
485 spin_lock_irq (&data->dev->lock);
486 if (likely (data->ep != NULL)) {
487 switch (code) {
488 case GADGETFS_FIFO_STATUS:
489 status = usb_ep_fifo_status (data->ep);
490 break;
491 case GADGETFS_FIFO_FLUSH:
492 usb_ep_fifo_flush (data->ep);
493 break;
494 case GADGETFS_CLEAR_HALT:
495 status = usb_ep_clear_halt (data->ep);
496 break;
497 default:
498 status = -ENOTTY;
499 }
500 } else
501 status = -ENODEV;
502 spin_unlock_irq (&data->dev->lock);
503 mutex_unlock(&data->lock);
504 return status;
505 }
506
507 /*----------------------------------------------------------------------*/
508
509 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
510
511 struct kiocb_priv {
512 struct usb_request *req;
513 struct ep_data *epdata;
514 struct kiocb *iocb;
515 struct mm_struct *mm;
516 struct work_struct work;
517 void *buf;
518 const struct iovec *iv;
519 unsigned long nr_segs;
520 unsigned actual;
521 };
522
523 static int ep_aio_cancel(struct kiocb *iocb)
524 {
525 struct kiocb_priv *priv = iocb->private;
526 struct ep_data *epdata;
527 int value;
528
529 local_irq_disable();
530 epdata = priv->epdata;
531 // spin_lock(&epdata->dev->lock);
532 if (likely(epdata && epdata->ep && priv->req))
533 value = usb_ep_dequeue (epdata->ep, priv->req);
534 else
535 value = -EINVAL;
536 // spin_unlock(&epdata->dev->lock);
537 local_irq_enable();
538
539 return value;
540 }
541
542 static ssize_t ep_copy_to_user(struct kiocb_priv *priv)
543 {
544 ssize_t len, total;
545 void *to_copy;
546 int i;
547
548 /* copy stuff into user buffers */
549 total = priv->actual;
550 len = 0;
551 to_copy = priv->buf;
552 for (i=0; i < priv->nr_segs; i++) {
553 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
554
555 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
556 if (len == 0)
557 len = -EFAULT;
558 break;
559 }
560
561 total -= this;
562 len += this;
563 to_copy += this;
564 if (total == 0)
565 break;
566 }
567
568 return len;
569 }
570
571 static void ep_user_copy_worker(struct work_struct *work)
572 {
573 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
574 struct mm_struct *mm = priv->mm;
575 struct kiocb *iocb = priv->iocb;
576 size_t ret;
577
578 use_mm(mm);
579 ret = ep_copy_to_user(priv);
580 unuse_mm(mm);
581
582 /* completing the iocb can drop the ctx and mm, don't touch mm after */
583 aio_complete(iocb, ret, ret);
584
585 kfree(priv->buf);
586 kfree(priv);
587 }
588
589 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
590 {
591 struct kiocb *iocb = req->context;
592 struct kiocb_priv *priv = iocb->private;
593 struct ep_data *epdata = priv->epdata;
594
595 /* lock against disconnect (and ideally, cancel) */
596 spin_lock(&epdata->dev->lock);
597 priv->req = NULL;
598 priv->epdata = NULL;
599
600 /* if this was a write or a read returning no data then we
601 * don't need to copy anything to userspace, so we can
602 * complete the aio request immediately.
603 */
604 if (priv->iv == NULL || unlikely(req->actual == 0)) {
605 kfree(req->buf);
606 kfree(priv);
607 iocb->private = NULL;
608 /* aio_complete() reports bytes-transferred _and_ faults */
609 aio_complete(iocb, req->actual ? req->actual : req->status,
610 req->status);
611 } else {
612 /* ep_copy_to_user() won't report both; we hide some faults */
613 if (unlikely(0 != req->status))
614 DBG(epdata->dev, "%s fault %d len %d\n",
615 ep->name, req->status, req->actual);
616
617 priv->buf = req->buf;
618 priv->actual = req->actual;
619 schedule_work(&priv->work);
620 }
621 spin_unlock(&epdata->dev->lock);
622
623 usb_ep_free_request(ep, req);
624 put_ep(epdata);
625 }
626
627 static ssize_t
628 ep_aio_rwtail(
629 struct kiocb *iocb,
630 char *buf,
631 size_t len,
632 struct ep_data *epdata,
633 const struct iovec *iv,
634 unsigned long nr_segs
635 )
636 {
637 struct kiocb_priv *priv;
638 struct usb_request *req;
639 ssize_t value;
640
641 priv = kmalloc(sizeof *priv, GFP_KERNEL);
642 if (!priv) {
643 value = -ENOMEM;
644 fail:
645 kfree(buf);
646 return value;
647 }
648 iocb->private = priv;
649 priv->iocb = iocb;
650 priv->iv = iv;
651 priv->nr_segs = nr_segs;
652 INIT_WORK(&priv->work, ep_user_copy_worker);
653
654 value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
655 if (unlikely(value < 0)) {
656 kfree(priv);
657 goto fail;
658 }
659
660 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
661 get_ep(epdata);
662 priv->epdata = epdata;
663 priv->actual = 0;
664 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
665
666 /* each kiocb is coupled to one usb_request, but we can't
667 * allocate or submit those if the host disconnected.
668 */
669 spin_lock_irq(&epdata->dev->lock);
670 if (likely(epdata->ep)) {
671 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
672 if (likely(req)) {
673 priv->req = req;
674 req->buf = buf;
675 req->length = len;
676 req->complete = ep_aio_complete;
677 req->context = iocb;
678 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
679 if (unlikely(0 != value))
680 usb_ep_free_request(epdata->ep, req);
681 } else
682 value = -EAGAIN;
683 } else
684 value = -ENODEV;
685 spin_unlock_irq(&epdata->dev->lock);
686
687 mutex_unlock(&epdata->lock);
688
689 if (unlikely(value)) {
690 kfree(priv);
691 put_ep(epdata);
692 } else
693 value = -EIOCBQUEUED;
694 return value;
695 }
696
697 static ssize_t
698 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
699 unsigned long nr_segs, loff_t o)
700 {
701 struct ep_data *epdata = iocb->ki_filp->private_data;
702 char *buf;
703
704 if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
705 return -EINVAL;
706
707 buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
708 if (unlikely(!buf))
709 return -ENOMEM;
710
711 return ep_aio_rwtail(iocb, buf, iocb->ki_nbytes, epdata, iov, nr_segs);
712 }
713
714 static ssize_t
715 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
716 unsigned long nr_segs, loff_t o)
717 {
718 struct ep_data *epdata = iocb->ki_filp->private_data;
719 char *buf;
720 size_t len = 0;
721 int i = 0;
722
723 if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
724 return -EINVAL;
725
726 buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
727 if (unlikely(!buf))
728 return -ENOMEM;
729
730 for (i=0; i < nr_segs; i++) {
731 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
732 iov[i].iov_len) != 0)) {
733 kfree(buf);
734 return -EFAULT;
735 }
736 len += iov[i].iov_len;
737 }
738 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
739 }
740
741 /*----------------------------------------------------------------------*/
742
743 /* used after endpoint configuration */
744 static const struct file_operations ep_io_operations = {
745 .owner = THIS_MODULE,
746 .llseek = no_llseek,
747
748 .read = ep_read,
749 .write = ep_write,
750 .unlocked_ioctl = ep_ioctl,
751 .release = ep_release,
752
753 .aio_read = ep_aio_read,
754 .aio_write = ep_aio_write,
755 };
756
757 /* ENDPOINT INITIALIZATION
758 *
759 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
760 * status = write (fd, descriptors, sizeof descriptors)
761 *
762 * That write establishes the endpoint configuration, configuring
763 * the controller to process bulk, interrupt, or isochronous transfers
764 * at the right maxpacket size, and so on.
765 *
766 * The descriptors are message type 1, identified by a host order u32
767 * at the beginning of what's written. Descriptor order is: full/low
768 * speed descriptor, then optional high speed descriptor.
769 */
770 static ssize_t
771 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
772 {
773 struct ep_data *data = fd->private_data;
774 struct usb_ep *ep;
775 u32 tag;
776 int value, length = len;
777
778 value = mutex_lock_interruptible(&data->lock);
779 if (value < 0)
780 return value;
781
782 if (data->state != STATE_EP_READY) {
783 value = -EL2HLT;
784 goto fail;
785 }
786
787 value = len;
788 if (len < USB_DT_ENDPOINT_SIZE + 4)
789 goto fail0;
790
791 /* we might need to change message format someday */
792 if (copy_from_user (&tag, buf, 4)) {
793 goto fail1;
794 }
795 if (tag != 1) {
796 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
797 goto fail0;
798 }
799 buf += 4;
800 len -= 4;
801
802 /* NOTE: audio endpoint extensions not accepted here;
803 * just don't include the extra bytes.
804 */
805
806 /* full/low speed descriptor, then high speed */
807 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
808 goto fail1;
809 }
810 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
811 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
812 goto fail0;
813 if (len != USB_DT_ENDPOINT_SIZE) {
814 if (len != 2 * USB_DT_ENDPOINT_SIZE)
815 goto fail0;
816 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
817 USB_DT_ENDPOINT_SIZE)) {
818 goto fail1;
819 }
820 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
821 || data->hs_desc.bDescriptorType
822 != USB_DT_ENDPOINT) {
823 DBG(data->dev, "config %s, bad hs length or type\n",
824 data->name);
825 goto fail0;
826 }
827 }
828
829 spin_lock_irq (&data->dev->lock);
830 if (data->dev->state == STATE_DEV_UNBOUND) {
831 value = -ENOENT;
832 goto gone;
833 } else if ((ep = data->ep) == NULL) {
834 value = -ENODEV;
835 goto gone;
836 }
837 switch (data->dev->gadget->speed) {
838 case USB_SPEED_LOW:
839 case USB_SPEED_FULL:
840 ep->desc = &data->desc;
841 value = usb_ep_enable(ep);
842 if (value == 0)
843 data->state = STATE_EP_ENABLED;
844 break;
845 case USB_SPEED_HIGH:
846 /* fails if caller didn't provide that descriptor... */
847 ep->desc = &data->hs_desc;
848 value = usb_ep_enable(ep);
849 if (value == 0)
850 data->state = STATE_EP_ENABLED;
851 break;
852 default:
853 DBG(data->dev, "unconnected, %s init abandoned\n",
854 data->name);
855 value = -EINVAL;
856 }
857 if (value == 0) {
858 fd->f_op = &ep_io_operations;
859 value = length;
860 }
861 gone:
862 spin_unlock_irq (&data->dev->lock);
863 if (value < 0) {
864 fail:
865 data->desc.bDescriptorType = 0;
866 data->hs_desc.bDescriptorType = 0;
867 }
868 mutex_unlock(&data->lock);
869 return value;
870 fail0:
871 value = -EINVAL;
872 goto fail;
873 fail1:
874 value = -EFAULT;
875 goto fail;
876 }
877
878 static int
879 ep_open (struct inode *inode, struct file *fd)
880 {
881 struct ep_data *data = inode->i_private;
882 int value = -EBUSY;
883
884 if (mutex_lock_interruptible(&data->lock) != 0)
885 return -EINTR;
886 spin_lock_irq (&data->dev->lock);
887 if (data->dev->state == STATE_DEV_UNBOUND)
888 value = -ENOENT;
889 else if (data->state == STATE_EP_DISABLED) {
890 value = 0;
891 data->state = STATE_EP_READY;
892 get_ep (data);
893 fd->private_data = data;
894 VDEBUG (data->dev, "%s ready\n", data->name);
895 } else
896 DBG (data->dev, "%s state %d\n",
897 data->name, data->state);
898 spin_unlock_irq (&data->dev->lock);
899 mutex_unlock(&data->lock);
900 return value;
901 }
902
903 /* used before endpoint configuration */
904 static const struct file_operations ep_config_operations = {
905 .llseek = no_llseek,
906
907 .open = ep_open,
908 .write = ep_config,
909 .release = ep_release,
910 };
911
912 /*----------------------------------------------------------------------*/
913
914 /* EP0 IMPLEMENTATION can be partly in userspace.
915 *
916 * Drivers that use this facility receive various events, including
917 * control requests the kernel doesn't handle. Drivers that don't
918 * use this facility may be too simple-minded for real applications.
919 */
920
921 static inline void ep0_readable (struct dev_data *dev)
922 {
923 wake_up (&dev->wait);
924 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
925 }
926
927 static void clean_req (struct usb_ep *ep, struct usb_request *req)
928 {
929 struct dev_data *dev = ep->driver_data;
930
931 if (req->buf != dev->rbuf) {
932 kfree(req->buf);
933 req->buf = dev->rbuf;
934 }
935 req->complete = epio_complete;
936 dev->setup_out_ready = 0;
937 }
938
939 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
940 {
941 struct dev_data *dev = ep->driver_data;
942 unsigned long flags;
943 int free = 1;
944
945 /* for control OUT, data must still get to userspace */
946 spin_lock_irqsave(&dev->lock, flags);
947 if (!dev->setup_in) {
948 dev->setup_out_error = (req->status != 0);
949 if (!dev->setup_out_error)
950 free = 0;
951 dev->setup_out_ready = 1;
952 ep0_readable (dev);
953 }
954
955 /* clean up as appropriate */
956 if (free && req->buf != &dev->rbuf)
957 clean_req (ep, req);
958 req->complete = epio_complete;
959 spin_unlock_irqrestore(&dev->lock, flags);
960 }
961
962 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
963 {
964 struct dev_data *dev = ep->driver_data;
965
966 if (dev->setup_out_ready) {
967 DBG (dev, "ep0 request busy!\n");
968 return -EBUSY;
969 }
970 if (len > sizeof (dev->rbuf))
971 req->buf = kmalloc(len, GFP_ATOMIC);
972 if (req->buf == NULL) {
973 req->buf = dev->rbuf;
974 return -ENOMEM;
975 }
976 req->complete = ep0_complete;
977 req->length = len;
978 req->zero = 0;
979 return 0;
980 }
981
982 static ssize_t
983 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
984 {
985 struct dev_data *dev = fd->private_data;
986 ssize_t retval;
987 enum ep0_state state;
988
989 spin_lock_irq (&dev->lock);
990
991 /* report fd mode change before acting on it */
992 if (dev->setup_abort) {
993 dev->setup_abort = 0;
994 retval = -EIDRM;
995 goto done;
996 }
997
998 /* control DATA stage */
999 if ((state = dev->state) == STATE_DEV_SETUP) {
1000
1001 if (dev->setup_in) { /* stall IN */
1002 VDEBUG(dev, "ep0in stall\n");
1003 (void) usb_ep_set_halt (dev->gadget->ep0);
1004 retval = -EL2HLT;
1005 dev->state = STATE_DEV_CONNECTED;
1006
1007 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
1008 struct usb_ep *ep = dev->gadget->ep0;
1009 struct usb_request *req = dev->req;
1010
1011 if ((retval = setup_req (ep, req, 0)) == 0)
1012 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1013 dev->state = STATE_DEV_CONNECTED;
1014
1015 /* assume that was SET_CONFIGURATION */
1016 if (dev->current_config) {
1017 unsigned power;
1018
1019 if (gadget_is_dualspeed(dev->gadget)
1020 && (dev->gadget->speed
1021 == USB_SPEED_HIGH))
1022 power = dev->hs_config->bMaxPower;
1023 else
1024 power = dev->config->bMaxPower;
1025 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1026 }
1027
1028 } else { /* collect OUT data */
1029 if ((fd->f_flags & O_NONBLOCK) != 0
1030 && !dev->setup_out_ready) {
1031 retval = -EAGAIN;
1032 goto done;
1033 }
1034 spin_unlock_irq (&dev->lock);
1035 retval = wait_event_interruptible (dev->wait,
1036 dev->setup_out_ready != 0);
1037
1038 /* FIXME state could change from under us */
1039 spin_lock_irq (&dev->lock);
1040 if (retval)
1041 goto done;
1042
1043 if (dev->state != STATE_DEV_SETUP) {
1044 retval = -ECANCELED;
1045 goto done;
1046 }
1047 dev->state = STATE_DEV_CONNECTED;
1048
1049 if (dev->setup_out_error)
1050 retval = -EIO;
1051 else {
1052 len = min (len, (size_t)dev->req->actual);
1053 // FIXME don't call this with the spinlock held ...
1054 if (copy_to_user (buf, dev->req->buf, len))
1055 retval = -EFAULT;
1056 else
1057 retval = len;
1058 clean_req (dev->gadget->ep0, dev->req);
1059 /* NOTE userspace can't yet choose to stall */
1060 }
1061 }
1062 goto done;
1063 }
1064
1065 /* else normal: return event data */
1066 if (len < sizeof dev->event [0]) {
1067 retval = -EINVAL;
1068 goto done;
1069 }
1070 len -= len % sizeof (struct usb_gadgetfs_event);
1071 dev->usermode_setup = 1;
1072
1073 scan:
1074 /* return queued events right away */
1075 if (dev->ev_next != 0) {
1076 unsigned i, n;
1077
1078 n = len / sizeof (struct usb_gadgetfs_event);
1079 if (dev->ev_next < n)
1080 n = dev->ev_next;
1081
1082 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1083 for (i = 0; i < n; i++) {
1084 if (dev->event [i].type == GADGETFS_SETUP) {
1085 dev->state = STATE_DEV_SETUP;
1086 n = i + 1;
1087 break;
1088 }
1089 }
1090 spin_unlock_irq (&dev->lock);
1091 len = n * sizeof (struct usb_gadgetfs_event);
1092 if (copy_to_user (buf, &dev->event, len))
1093 retval = -EFAULT;
1094 else
1095 retval = len;
1096 if (len > 0) {
1097 /* NOTE this doesn't guard against broken drivers;
1098 * concurrent ep0 readers may lose events.
1099 */
1100 spin_lock_irq (&dev->lock);
1101 if (dev->ev_next > n) {
1102 memmove(&dev->event[0], &dev->event[n],
1103 sizeof (struct usb_gadgetfs_event)
1104 * (dev->ev_next - n));
1105 }
1106 dev->ev_next -= n;
1107 spin_unlock_irq (&dev->lock);
1108 }
1109 return retval;
1110 }
1111 if (fd->f_flags & O_NONBLOCK) {
1112 retval = -EAGAIN;
1113 goto done;
1114 }
1115
1116 switch (state) {
1117 default:
1118 DBG (dev, "fail %s, state %d\n", __func__, state);
1119 retval = -ESRCH;
1120 break;
1121 case STATE_DEV_UNCONNECTED:
1122 case STATE_DEV_CONNECTED:
1123 spin_unlock_irq (&dev->lock);
1124 DBG (dev, "%s wait\n", __func__);
1125
1126 /* wait for events */
1127 retval = wait_event_interruptible (dev->wait,
1128 dev->ev_next != 0);
1129 if (retval < 0)
1130 return retval;
1131 spin_lock_irq (&dev->lock);
1132 goto scan;
1133 }
1134
1135 done:
1136 spin_unlock_irq (&dev->lock);
1137 return retval;
1138 }
1139
1140 static struct usb_gadgetfs_event *
1141 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1142 {
1143 struct usb_gadgetfs_event *event;
1144 unsigned i;
1145
1146 switch (type) {
1147 /* these events purge the queue */
1148 case GADGETFS_DISCONNECT:
1149 if (dev->state == STATE_DEV_SETUP)
1150 dev->setup_abort = 1;
1151 // FALL THROUGH
1152 case GADGETFS_CONNECT:
1153 dev->ev_next = 0;
1154 break;
1155 case GADGETFS_SETUP: /* previous request timed out */
1156 case GADGETFS_SUSPEND: /* same effect */
1157 /* these events can't be repeated */
1158 for (i = 0; i != dev->ev_next; i++) {
1159 if (dev->event [i].type != type)
1160 continue;
1161 DBG(dev, "discard old event[%d] %d\n", i, type);
1162 dev->ev_next--;
1163 if (i == dev->ev_next)
1164 break;
1165 /* indices start at zero, for simplicity */
1166 memmove (&dev->event [i], &dev->event [i + 1],
1167 sizeof (struct usb_gadgetfs_event)
1168 * (dev->ev_next - i));
1169 }
1170 break;
1171 default:
1172 BUG ();
1173 }
1174 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1175 event = &dev->event [dev->ev_next++];
1176 BUG_ON (dev->ev_next > N_EVENT);
1177 memset (event, 0, sizeof *event);
1178 event->type = type;
1179 return event;
1180 }
1181
1182 static ssize_t
1183 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1184 {
1185 struct dev_data *dev = fd->private_data;
1186 ssize_t retval = -ESRCH;
1187
1188 spin_lock_irq (&dev->lock);
1189
1190 /* report fd mode change before acting on it */
1191 if (dev->setup_abort) {
1192 dev->setup_abort = 0;
1193 retval = -EIDRM;
1194
1195 /* data and/or status stage for control request */
1196 } else if (dev->state == STATE_DEV_SETUP) {
1197
1198 /* IN DATA+STATUS caller makes len <= wLength */
1199 if (dev->setup_in) {
1200 retval = setup_req (dev->gadget->ep0, dev->req, len);
1201 if (retval == 0) {
1202 dev->state = STATE_DEV_CONNECTED;
1203 spin_unlock_irq (&dev->lock);
1204 if (copy_from_user (dev->req->buf, buf, len))
1205 retval = -EFAULT;
1206 else {
1207 if (len < dev->setup_wLength)
1208 dev->req->zero = 1;
1209 retval = usb_ep_queue (
1210 dev->gadget->ep0, dev->req,
1211 GFP_KERNEL);
1212 }
1213 if (retval < 0) {
1214 spin_lock_irq (&dev->lock);
1215 clean_req (dev->gadget->ep0, dev->req);
1216 spin_unlock_irq (&dev->lock);
1217 } else
1218 retval = len;
1219
1220 return retval;
1221 }
1222
1223 /* can stall some OUT transfers */
1224 } else if (dev->setup_can_stall) {
1225 VDEBUG(dev, "ep0out stall\n");
1226 (void) usb_ep_set_halt (dev->gadget->ep0);
1227 retval = -EL2HLT;
1228 dev->state = STATE_DEV_CONNECTED;
1229 } else {
1230 DBG(dev, "bogus ep0out stall!\n");
1231 }
1232 } else
1233 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1234
1235 spin_unlock_irq (&dev->lock);
1236 return retval;
1237 }
1238
1239 static int
1240 ep0_fasync (int f, struct file *fd, int on)
1241 {
1242 struct dev_data *dev = fd->private_data;
1243 // caller must F_SETOWN before signal delivery happens
1244 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1245 return fasync_helper (f, fd, on, &dev->fasync);
1246 }
1247
1248 static struct usb_gadget_driver gadgetfs_driver;
1249
1250 static int
1251 dev_release (struct inode *inode, struct file *fd)
1252 {
1253 struct dev_data *dev = fd->private_data;
1254
1255 /* closing ep0 === shutdown all */
1256
1257 usb_gadget_unregister_driver (&gadgetfs_driver);
1258
1259 /* at this point "good" hardware has disconnected the
1260 * device from USB; the host won't see it any more.
1261 * alternatively, all host requests will time out.
1262 */
1263
1264 kfree (dev->buf);
1265 dev->buf = NULL;
1266
1267 /* other endpoints were all decoupled from this device */
1268 spin_lock_irq(&dev->lock);
1269 dev->state = STATE_DEV_DISABLED;
1270 spin_unlock_irq(&dev->lock);
1271
1272 put_dev (dev);
1273 return 0;
1274 }
1275
1276 static unsigned int
1277 ep0_poll (struct file *fd, poll_table *wait)
1278 {
1279 struct dev_data *dev = fd->private_data;
1280 int mask = 0;
1281
1282 poll_wait(fd, &dev->wait, wait);
1283
1284 spin_lock_irq (&dev->lock);
1285
1286 /* report fd mode change before acting on it */
1287 if (dev->setup_abort) {
1288 dev->setup_abort = 0;
1289 mask = POLLHUP;
1290 goto out;
1291 }
1292
1293 if (dev->state == STATE_DEV_SETUP) {
1294 if (dev->setup_in || dev->setup_can_stall)
1295 mask = POLLOUT;
1296 } else {
1297 if (dev->ev_next != 0)
1298 mask = POLLIN;
1299 }
1300 out:
1301 spin_unlock_irq(&dev->lock);
1302 return mask;
1303 }
1304
1305 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1306 {
1307 struct dev_data *dev = fd->private_data;
1308 struct usb_gadget *gadget = dev->gadget;
1309 long ret = -ENOTTY;
1310
1311 if (gadget->ops->ioctl)
1312 ret = gadget->ops->ioctl (gadget, code, value);
1313
1314 return ret;
1315 }
1316
1317 /* used after device configuration */
1318 static const struct file_operations ep0_io_operations = {
1319 .owner = THIS_MODULE,
1320 .llseek = no_llseek,
1321
1322 .read = ep0_read,
1323 .write = ep0_write,
1324 .fasync = ep0_fasync,
1325 .poll = ep0_poll,
1326 .unlocked_ioctl = dev_ioctl,
1327 .release = dev_release,
1328 };
1329
1330 /*----------------------------------------------------------------------*/
1331
1332 /* The in-kernel gadget driver handles most ep0 issues, in particular
1333 * enumerating the single configuration (as provided from user space).
1334 *
1335 * Unrecognized ep0 requests may be handled in user space.
1336 */
1337
1338 static void make_qualifier (struct dev_data *dev)
1339 {
1340 struct usb_qualifier_descriptor qual;
1341 struct usb_device_descriptor *desc;
1342
1343 qual.bLength = sizeof qual;
1344 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1345 qual.bcdUSB = cpu_to_le16 (0x0200);
1346
1347 desc = dev->dev;
1348 qual.bDeviceClass = desc->bDeviceClass;
1349 qual.bDeviceSubClass = desc->bDeviceSubClass;
1350 qual.bDeviceProtocol = desc->bDeviceProtocol;
1351
1352 /* assumes ep0 uses the same value for both speeds ... */
1353 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1354
1355 qual.bNumConfigurations = 1;
1356 qual.bRESERVED = 0;
1357
1358 memcpy (dev->rbuf, &qual, sizeof qual);
1359 }
1360
1361 static int
1362 config_buf (struct dev_data *dev, u8 type, unsigned index)
1363 {
1364 int len;
1365 int hs = 0;
1366
1367 /* only one configuration */
1368 if (index > 0)
1369 return -EINVAL;
1370
1371 if (gadget_is_dualspeed(dev->gadget)) {
1372 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1373 if (type == USB_DT_OTHER_SPEED_CONFIG)
1374 hs = !hs;
1375 }
1376 if (hs) {
1377 dev->req->buf = dev->hs_config;
1378 len = le16_to_cpu(dev->hs_config->wTotalLength);
1379 } else {
1380 dev->req->buf = dev->config;
1381 len = le16_to_cpu(dev->config->wTotalLength);
1382 }
1383 ((u8 *)dev->req->buf) [1] = type;
1384 return len;
1385 }
1386
1387 static int
1388 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1389 {
1390 struct dev_data *dev = get_gadget_data (gadget);
1391 struct usb_request *req = dev->req;
1392 int value = -EOPNOTSUPP;
1393 struct usb_gadgetfs_event *event;
1394 u16 w_value = le16_to_cpu(ctrl->wValue);
1395 u16 w_length = le16_to_cpu(ctrl->wLength);
1396
1397 spin_lock (&dev->lock);
1398 dev->setup_abort = 0;
1399 if (dev->state == STATE_DEV_UNCONNECTED) {
1400 if (gadget_is_dualspeed(gadget)
1401 && gadget->speed == USB_SPEED_HIGH
1402 && dev->hs_config == NULL) {
1403 spin_unlock(&dev->lock);
1404 ERROR (dev, "no high speed config??\n");
1405 return -EINVAL;
1406 }
1407
1408 dev->state = STATE_DEV_CONNECTED;
1409
1410 INFO (dev, "connected\n");
1411 event = next_event (dev, GADGETFS_CONNECT);
1412 event->u.speed = gadget->speed;
1413 ep0_readable (dev);
1414
1415 /* host may have given up waiting for response. we can miss control
1416 * requests handled lower down (device/endpoint status and features);
1417 * then ep0_{read,write} will report the wrong status. controller
1418 * driver will have aborted pending i/o.
1419 */
1420 } else if (dev->state == STATE_DEV_SETUP)
1421 dev->setup_abort = 1;
1422
1423 req->buf = dev->rbuf;
1424 req->context = NULL;
1425 value = -EOPNOTSUPP;
1426 switch (ctrl->bRequest) {
1427
1428 case USB_REQ_GET_DESCRIPTOR:
1429 if (ctrl->bRequestType != USB_DIR_IN)
1430 goto unrecognized;
1431 switch (w_value >> 8) {
1432
1433 case USB_DT_DEVICE:
1434 value = min (w_length, (u16) sizeof *dev->dev);
1435 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1436 req->buf = dev->dev;
1437 break;
1438 case USB_DT_DEVICE_QUALIFIER:
1439 if (!dev->hs_config)
1440 break;
1441 value = min (w_length, (u16)
1442 sizeof (struct usb_qualifier_descriptor));
1443 make_qualifier (dev);
1444 break;
1445 case USB_DT_OTHER_SPEED_CONFIG:
1446 // FALLTHROUGH
1447 case USB_DT_CONFIG:
1448 value = config_buf (dev,
1449 w_value >> 8,
1450 w_value & 0xff);
1451 if (value >= 0)
1452 value = min (w_length, (u16) value);
1453 break;
1454 case USB_DT_STRING:
1455 goto unrecognized;
1456
1457 default: // all others are errors
1458 break;
1459 }
1460 break;
1461
1462 /* currently one config, two speeds */
1463 case USB_REQ_SET_CONFIGURATION:
1464 if (ctrl->bRequestType != 0)
1465 goto unrecognized;
1466 if (0 == (u8) w_value) {
1467 value = 0;
1468 dev->current_config = 0;
1469 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1470 // user mode expected to disable endpoints
1471 } else {
1472 u8 config, power;
1473
1474 if (gadget_is_dualspeed(gadget)
1475 && gadget->speed == USB_SPEED_HIGH) {
1476 config = dev->hs_config->bConfigurationValue;
1477 power = dev->hs_config->bMaxPower;
1478 } else {
1479 config = dev->config->bConfigurationValue;
1480 power = dev->config->bMaxPower;
1481 }
1482
1483 if (config == (u8) w_value) {
1484 value = 0;
1485 dev->current_config = config;
1486 usb_gadget_vbus_draw(gadget, 2 * power);
1487 }
1488 }
1489
1490 /* report SET_CONFIGURATION like any other control request,
1491 * except that usermode may not stall this. the next
1492 * request mustn't be allowed start until this finishes:
1493 * endpoints and threads set up, etc.
1494 *
1495 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1496 * has bad/racey automagic that prevents synchronizing here.
1497 * even kernel mode drivers often miss them.
1498 */
1499 if (value == 0) {
1500 INFO (dev, "configuration #%d\n", dev->current_config);
1501 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1502 if (dev->usermode_setup) {
1503 dev->setup_can_stall = 0;
1504 goto delegate;
1505 }
1506 }
1507 break;
1508
1509 #ifndef CONFIG_USB_PXA25X
1510 /* PXA automagically handles this request too */
1511 case USB_REQ_GET_CONFIGURATION:
1512 if (ctrl->bRequestType != 0x80)
1513 goto unrecognized;
1514 *(u8 *)req->buf = dev->current_config;
1515 value = min (w_length, (u16) 1);
1516 break;
1517 #endif
1518
1519 default:
1520 unrecognized:
1521 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1522 dev->usermode_setup ? "delegate" : "fail",
1523 ctrl->bRequestType, ctrl->bRequest,
1524 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1525
1526 /* if there's an ep0 reader, don't stall */
1527 if (dev->usermode_setup) {
1528 dev->setup_can_stall = 1;
1529 delegate:
1530 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1531 ? 1 : 0;
1532 dev->setup_wLength = w_length;
1533 dev->setup_out_ready = 0;
1534 dev->setup_out_error = 0;
1535 value = 0;
1536
1537 /* read DATA stage for OUT right away */
1538 if (unlikely (!dev->setup_in && w_length)) {
1539 value = setup_req (gadget->ep0, dev->req,
1540 w_length);
1541 if (value < 0)
1542 break;
1543 value = usb_ep_queue (gadget->ep0, dev->req,
1544 GFP_ATOMIC);
1545 if (value < 0) {
1546 clean_req (gadget->ep0, dev->req);
1547 break;
1548 }
1549
1550 /* we can't currently stall these */
1551 dev->setup_can_stall = 0;
1552 }
1553
1554 /* state changes when reader collects event */
1555 event = next_event (dev, GADGETFS_SETUP);
1556 event->u.setup = *ctrl;
1557 ep0_readable (dev);
1558 spin_unlock (&dev->lock);
1559 return 0;
1560 }
1561 }
1562
1563 /* proceed with data transfer and status phases? */
1564 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1565 req->length = value;
1566 req->zero = value < w_length;
1567 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1568 if (value < 0) {
1569 DBG (dev, "ep_queue --> %d\n", value);
1570 req->status = 0;
1571 }
1572 }
1573
1574 /* device stalls when value < 0 */
1575 spin_unlock (&dev->lock);
1576 return value;
1577 }
1578
1579 static void destroy_ep_files (struct dev_data *dev)
1580 {
1581 DBG (dev, "%s %d\n", __func__, dev->state);
1582
1583 /* dev->state must prevent interference */
1584 spin_lock_irq (&dev->lock);
1585 while (!list_empty(&dev->epfiles)) {
1586 struct ep_data *ep;
1587 struct inode *parent;
1588 struct dentry *dentry;
1589
1590 /* break link to FS */
1591 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1592 list_del_init (&ep->epfiles);
1593 dentry = ep->dentry;
1594 ep->dentry = NULL;
1595 parent = dentry->d_parent->d_inode;
1596
1597 /* break link to controller */
1598 if (ep->state == STATE_EP_ENABLED)
1599 (void) usb_ep_disable (ep->ep);
1600 ep->state = STATE_EP_UNBOUND;
1601 usb_ep_free_request (ep->ep, ep->req);
1602 ep->ep = NULL;
1603 wake_up (&ep->wait);
1604 put_ep (ep);
1605
1606 spin_unlock_irq (&dev->lock);
1607
1608 /* break link to dcache */
1609 mutex_lock (&parent->i_mutex);
1610 d_delete (dentry);
1611 dput (dentry);
1612 mutex_unlock (&parent->i_mutex);
1613
1614 spin_lock_irq (&dev->lock);
1615 }
1616 spin_unlock_irq (&dev->lock);
1617 }
1618
1619
1620 static struct dentry *
1621 gadgetfs_create_file (struct super_block *sb, char const *name,
1622 void *data, const struct file_operations *fops);
1623
1624 static int activate_ep_files (struct dev_data *dev)
1625 {
1626 struct usb_ep *ep;
1627 struct ep_data *data;
1628
1629 gadget_for_each_ep (ep, dev->gadget) {
1630
1631 data = kzalloc(sizeof(*data), GFP_KERNEL);
1632 if (!data)
1633 goto enomem0;
1634 data->state = STATE_EP_DISABLED;
1635 mutex_init(&data->lock);
1636 init_waitqueue_head (&data->wait);
1637
1638 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1639 atomic_set (&data->count, 1);
1640 data->dev = dev;
1641 get_dev (dev);
1642
1643 data->ep = ep;
1644 ep->driver_data = data;
1645
1646 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1647 if (!data->req)
1648 goto enomem1;
1649
1650 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1651 data, &ep_config_operations);
1652 if (!data->dentry)
1653 goto enomem2;
1654 list_add_tail (&data->epfiles, &dev->epfiles);
1655 }
1656 return 0;
1657
1658 enomem2:
1659 usb_ep_free_request (ep, data->req);
1660 enomem1:
1661 put_dev (dev);
1662 kfree (data);
1663 enomem0:
1664 DBG (dev, "%s enomem\n", __func__);
1665 destroy_ep_files (dev);
1666 return -ENOMEM;
1667 }
1668
1669 static void
1670 gadgetfs_unbind (struct usb_gadget *gadget)
1671 {
1672 struct dev_data *dev = get_gadget_data (gadget);
1673
1674 DBG (dev, "%s\n", __func__);
1675
1676 spin_lock_irq (&dev->lock);
1677 dev->state = STATE_DEV_UNBOUND;
1678 spin_unlock_irq (&dev->lock);
1679
1680 destroy_ep_files (dev);
1681 gadget->ep0->driver_data = NULL;
1682 set_gadget_data (gadget, NULL);
1683
1684 /* we've already been disconnected ... no i/o is active */
1685 if (dev->req)
1686 usb_ep_free_request (gadget->ep0, dev->req);
1687 DBG (dev, "%s done\n", __func__);
1688 put_dev (dev);
1689 }
1690
1691 static struct dev_data *the_device;
1692
1693 static int gadgetfs_bind(struct usb_gadget *gadget,
1694 struct usb_gadget_driver *driver)
1695 {
1696 struct dev_data *dev = the_device;
1697
1698 if (!dev)
1699 return -ESRCH;
1700 if (0 != strcmp (CHIP, gadget->name)) {
1701 pr_err("%s expected %s controller not %s\n",
1702 shortname, CHIP, gadget->name);
1703 return -ENODEV;
1704 }
1705
1706 set_gadget_data (gadget, dev);
1707 dev->gadget = gadget;
1708 gadget->ep0->driver_data = dev;
1709
1710 /* preallocate control response and buffer */
1711 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1712 if (!dev->req)
1713 goto enomem;
1714 dev->req->context = NULL;
1715 dev->req->complete = epio_complete;
1716
1717 if (activate_ep_files (dev) < 0)
1718 goto enomem;
1719
1720 INFO (dev, "bound to %s driver\n", gadget->name);
1721 spin_lock_irq(&dev->lock);
1722 dev->state = STATE_DEV_UNCONNECTED;
1723 spin_unlock_irq(&dev->lock);
1724 get_dev (dev);
1725 return 0;
1726
1727 enomem:
1728 gadgetfs_unbind (gadget);
1729 return -ENOMEM;
1730 }
1731
1732 static void
1733 gadgetfs_disconnect (struct usb_gadget *gadget)
1734 {
1735 struct dev_data *dev = get_gadget_data (gadget);
1736 unsigned long flags;
1737
1738 spin_lock_irqsave (&dev->lock, flags);
1739 if (dev->state == STATE_DEV_UNCONNECTED)
1740 goto exit;
1741 dev->state = STATE_DEV_UNCONNECTED;
1742
1743 INFO (dev, "disconnected\n");
1744 next_event (dev, GADGETFS_DISCONNECT);
1745 ep0_readable (dev);
1746 exit:
1747 spin_unlock_irqrestore (&dev->lock, flags);
1748 }
1749
1750 static void
1751 gadgetfs_suspend (struct usb_gadget *gadget)
1752 {
1753 struct dev_data *dev = get_gadget_data (gadget);
1754
1755 INFO (dev, "suspended from state %d\n", dev->state);
1756 spin_lock (&dev->lock);
1757 switch (dev->state) {
1758 case STATE_DEV_SETUP: // VERY odd... host died??
1759 case STATE_DEV_CONNECTED:
1760 case STATE_DEV_UNCONNECTED:
1761 next_event (dev, GADGETFS_SUSPEND);
1762 ep0_readable (dev);
1763 /* FALLTHROUGH */
1764 default:
1765 break;
1766 }
1767 spin_unlock (&dev->lock);
1768 }
1769
1770 static struct usb_gadget_driver gadgetfs_driver = {
1771 .function = (char *) driver_desc,
1772 .bind = gadgetfs_bind,
1773 .unbind = gadgetfs_unbind,
1774 .setup = gadgetfs_setup,
1775 .disconnect = gadgetfs_disconnect,
1776 .suspend = gadgetfs_suspend,
1777
1778 .driver = {
1779 .name = (char *) shortname,
1780 },
1781 };
1782
1783 /*----------------------------------------------------------------------*/
1784
1785 static void gadgetfs_nop(struct usb_gadget *arg) { }
1786
1787 static int gadgetfs_probe(struct usb_gadget *gadget,
1788 struct usb_gadget_driver *driver)
1789 {
1790 CHIP = gadget->name;
1791 return -EISNAM;
1792 }
1793
1794 static struct usb_gadget_driver probe_driver = {
1795 .max_speed = USB_SPEED_HIGH,
1796 .bind = gadgetfs_probe,
1797 .unbind = gadgetfs_nop,
1798 .setup = (void *)gadgetfs_nop,
1799 .disconnect = gadgetfs_nop,
1800 .driver = {
1801 .name = "nop",
1802 },
1803 };
1804
1805
1806 /* DEVICE INITIALIZATION
1807 *
1808 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1809 * status = write (fd, descriptors, sizeof descriptors)
1810 *
1811 * That write establishes the device configuration, so the kernel can
1812 * bind to the controller ... guaranteeing it can handle enumeration
1813 * at all necessary speeds. Descriptor order is:
1814 *
1815 * . message tag (u32, host order) ... for now, must be zero; it
1816 * would change to support features like multi-config devices
1817 * . full/low speed config ... all wTotalLength bytes (with interface,
1818 * class, altsetting, endpoint, and other descriptors)
1819 * . high speed config ... all descriptors, for high speed operation;
1820 * this one's optional except for high-speed hardware
1821 * . device descriptor
1822 *
1823 * Endpoints are not yet enabled. Drivers must wait until device
1824 * configuration and interface altsetting changes create
1825 * the need to configure (or unconfigure) them.
1826 *
1827 * After initialization, the device stays active for as long as that
1828 * $CHIP file is open. Events must then be read from that descriptor,
1829 * such as configuration notifications.
1830 */
1831
1832 static int is_valid_config (struct usb_config_descriptor *config)
1833 {
1834 return config->bDescriptorType == USB_DT_CONFIG
1835 && config->bLength == USB_DT_CONFIG_SIZE
1836 && config->bConfigurationValue != 0
1837 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1838 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1839 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1840 /* FIXME check lengths: walk to end */
1841 }
1842
1843 static ssize_t
1844 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1845 {
1846 struct dev_data *dev = fd->private_data;
1847 ssize_t value = len, length = len;
1848 unsigned total;
1849 u32 tag;
1850 char *kbuf;
1851
1852 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1853 return -EINVAL;
1854
1855 /* we might need to change message format someday */
1856 if (copy_from_user (&tag, buf, 4))
1857 return -EFAULT;
1858 if (tag != 0)
1859 return -EINVAL;
1860 buf += 4;
1861 length -= 4;
1862
1863 kbuf = memdup_user(buf, length);
1864 if (IS_ERR(kbuf))
1865 return PTR_ERR(kbuf);
1866
1867 spin_lock_irq (&dev->lock);
1868 value = -EINVAL;
1869 if (dev->buf)
1870 goto fail;
1871 dev->buf = kbuf;
1872
1873 /* full or low speed config */
1874 dev->config = (void *) kbuf;
1875 total = le16_to_cpu(dev->config->wTotalLength);
1876 if (!is_valid_config (dev->config) || total >= length)
1877 goto fail;
1878 kbuf += total;
1879 length -= total;
1880
1881 /* optional high speed config */
1882 if (kbuf [1] == USB_DT_CONFIG) {
1883 dev->hs_config = (void *) kbuf;
1884 total = le16_to_cpu(dev->hs_config->wTotalLength);
1885 if (!is_valid_config (dev->hs_config) || total >= length)
1886 goto fail;
1887 kbuf += total;
1888 length -= total;
1889 }
1890
1891 /* could support multiple configs, using another encoding! */
1892
1893 /* device descriptor (tweaked for paranoia) */
1894 if (length != USB_DT_DEVICE_SIZE)
1895 goto fail;
1896 dev->dev = (void *)kbuf;
1897 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1898 || dev->dev->bDescriptorType != USB_DT_DEVICE
1899 || dev->dev->bNumConfigurations != 1)
1900 goto fail;
1901 dev->dev->bNumConfigurations = 1;
1902 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1903
1904 /* triggers gadgetfs_bind(); then we can enumerate. */
1905 spin_unlock_irq (&dev->lock);
1906 if (dev->hs_config)
1907 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1908 else
1909 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1910
1911 value = usb_gadget_probe_driver(&gadgetfs_driver);
1912 if (value != 0) {
1913 kfree (dev->buf);
1914 dev->buf = NULL;
1915 } else {
1916 /* at this point "good" hardware has for the first time
1917 * let the USB the host see us. alternatively, if users
1918 * unplug/replug that will clear all the error state.
1919 *
1920 * note: everything running before here was guaranteed
1921 * to choke driver model style diagnostics. from here
1922 * on, they can work ... except in cleanup paths that
1923 * kick in after the ep0 descriptor is closed.
1924 */
1925 fd->f_op = &ep0_io_operations;
1926 value = len;
1927 }
1928 return value;
1929
1930 fail:
1931 spin_unlock_irq (&dev->lock);
1932 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1933 kfree (dev->buf);
1934 dev->buf = NULL;
1935 return value;
1936 }
1937
1938 static int
1939 dev_open (struct inode *inode, struct file *fd)
1940 {
1941 struct dev_data *dev = inode->i_private;
1942 int value = -EBUSY;
1943
1944 spin_lock_irq(&dev->lock);
1945 if (dev->state == STATE_DEV_DISABLED) {
1946 dev->ev_next = 0;
1947 dev->state = STATE_DEV_OPENED;
1948 fd->private_data = dev;
1949 get_dev (dev);
1950 value = 0;
1951 }
1952 spin_unlock_irq(&dev->lock);
1953 return value;
1954 }
1955
1956 static const struct file_operations dev_init_operations = {
1957 .llseek = no_llseek,
1958
1959 .open = dev_open,
1960 .write = dev_config,
1961 .fasync = ep0_fasync,
1962 .unlocked_ioctl = dev_ioctl,
1963 .release = dev_release,
1964 };
1965
1966 /*----------------------------------------------------------------------*/
1967
1968 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1969 *
1970 * Mounting the filesystem creates a controller file, used first for
1971 * device configuration then later for event monitoring.
1972 */
1973
1974
1975 /* FIXME PAM etc could set this security policy without mount options
1976 * if epfiles inherited ownership and permissons from ep0 ...
1977 */
1978
1979 static unsigned default_uid;
1980 static unsigned default_gid;
1981 static unsigned default_perm = S_IRUSR | S_IWUSR;
1982
1983 module_param (default_uid, uint, 0644);
1984 module_param (default_gid, uint, 0644);
1985 module_param (default_perm, uint, 0644);
1986
1987
1988 static struct inode *
1989 gadgetfs_make_inode (struct super_block *sb,
1990 void *data, const struct file_operations *fops,
1991 int mode)
1992 {
1993 struct inode *inode = new_inode (sb);
1994
1995 if (inode) {
1996 inode->i_ino = get_next_ino();
1997 inode->i_mode = mode;
1998 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1999 inode->i_gid = make_kgid(&init_user_ns, default_gid);
2000 inode->i_atime = inode->i_mtime = inode->i_ctime
2001 = CURRENT_TIME;
2002 inode->i_private = data;
2003 inode->i_fop = fops;
2004 }
2005 return inode;
2006 }
2007
2008 /* creates in fs root directory, so non-renamable and non-linkable.
2009 * so inode and dentry are paired, until device reconfig.
2010 */
2011 static struct dentry *
2012 gadgetfs_create_file (struct super_block *sb, char const *name,
2013 void *data, const struct file_operations *fops)
2014 {
2015 struct dentry *dentry;
2016 struct inode *inode;
2017
2018 dentry = d_alloc_name(sb->s_root, name);
2019 if (!dentry)
2020 return NULL;
2021
2022 inode = gadgetfs_make_inode (sb, data, fops,
2023 S_IFREG | (default_perm & S_IRWXUGO));
2024 if (!inode) {
2025 dput(dentry);
2026 return NULL;
2027 }
2028 d_add (dentry, inode);
2029 return dentry;
2030 }
2031
2032 static const struct super_operations gadget_fs_operations = {
2033 .statfs = simple_statfs,
2034 .drop_inode = generic_delete_inode,
2035 };
2036
2037 static int
2038 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2039 {
2040 struct inode *inode;
2041 struct dev_data *dev;
2042
2043 if (the_device)
2044 return -ESRCH;
2045
2046 /* fake probe to determine $CHIP */
2047 CHIP = NULL;
2048 usb_gadget_probe_driver(&probe_driver);
2049 if (!CHIP)
2050 return -ENODEV;
2051
2052 /* superblock */
2053 sb->s_blocksize = PAGE_CACHE_SIZE;
2054 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2055 sb->s_magic = GADGETFS_MAGIC;
2056 sb->s_op = &gadget_fs_operations;
2057 sb->s_time_gran = 1;
2058
2059 /* root inode */
2060 inode = gadgetfs_make_inode (sb,
2061 NULL, &simple_dir_operations,
2062 S_IFDIR | S_IRUGO | S_IXUGO);
2063 if (!inode)
2064 goto Enomem;
2065 inode->i_op = &simple_dir_inode_operations;
2066 if (!(sb->s_root = d_make_root (inode)))
2067 goto Enomem;
2068
2069 /* the ep0 file is named after the controller we expect;
2070 * user mode code can use it for sanity checks, like we do.
2071 */
2072 dev = dev_new ();
2073 if (!dev)
2074 goto Enomem;
2075
2076 dev->sb = sb;
2077 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &dev_init_operations);
2078 if (!dev->dentry) {
2079 put_dev(dev);
2080 goto Enomem;
2081 }
2082
2083 /* other endpoint files are available after hardware setup,
2084 * from binding to a controller.
2085 */
2086 the_device = dev;
2087 return 0;
2088
2089 Enomem:
2090 return -ENOMEM;
2091 }
2092
2093 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2094 static struct dentry *
2095 gadgetfs_mount (struct file_system_type *t, int flags,
2096 const char *path, void *opts)
2097 {
2098 return mount_single (t, flags, opts, gadgetfs_fill_super);
2099 }
2100
2101 static void
2102 gadgetfs_kill_sb (struct super_block *sb)
2103 {
2104 kill_litter_super (sb);
2105 if (the_device) {
2106 put_dev (the_device);
2107 the_device = NULL;
2108 }
2109 }
2110
2111 /*----------------------------------------------------------------------*/
2112
2113 static struct file_system_type gadgetfs_type = {
2114 .owner = THIS_MODULE,
2115 .name = shortname,
2116 .mount = gadgetfs_mount,
2117 .kill_sb = gadgetfs_kill_sb,
2118 };
2119 MODULE_ALIAS_FS("gadgetfs");
2120
2121 /*----------------------------------------------------------------------*/
2122
2123 static int __init init (void)
2124 {
2125 int status;
2126
2127 status = register_filesystem (&gadgetfs_type);
2128 if (status == 0)
2129 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2130 shortname, driver_desc);
2131 return status;
2132 }
2133 module_init (init);
2134
2135 static void __exit cleanup (void)
2136 {
2137 pr_debug ("unregister %s\n", shortname);
2138 unregister_filesystem (&gadgetfs_type);
2139 }
2140 module_exit (cleanup);
2141
Linux kernel - Deliverables
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