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Merge branch 'iov_iter' into for-davem
[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 #include <linux/uio.h>
30
31 #include <linux/device.h>
32 #include <linux/moduleparam.h>
33
34 #include <linux/usb/gadgetfs.h>
35 #include <linux/usb/gadget.h>
36
37
38 /*
39 * The gadgetfs API maps each endpoint to a file descriptor so that you
40 * can use standard synchronous read/write calls for I/O. There's some
41 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
42 * drivers show how this works in practice. You can also use AIO to
43 * eliminate I/O gaps between requests, to help when streaming data.
44 *
45 * Key parts that must be USB-specific are protocols defining how the
46 * read/write operations relate to the hardware state machines. There
47 * are two types of files. One type is for the device, implementing ep0.
48 * The other type is for each IN or OUT endpoint. In both cases, the
49 * user mode driver must configure the hardware before using it.
50 *
51 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
52 * (by writing configuration and device descriptors). Afterwards it
53 * may serve as a source of device events, used to handle all control
54 * requests other than basic enumeration.
55 *
56 * - Then, after a SET_CONFIGURATION control request, ep_config() is
57 * called when each /dev/gadget/ep* file is configured (by writing
58 * endpoint descriptors). Afterwards these files are used to write()
59 * IN data or to read() OUT data. To halt the endpoint, a "wrong
60 * direction" request is issued (like reading an IN endpoint).
61 *
62 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
63 * not possible on all hardware. For example, precise fault handling with
64 * respect to data left in endpoint fifos after aborted operations; or
65 * selective clearing of endpoint halts, to implement SET_INTERFACE.
66 */
67
68 #define DRIVER_DESC "USB Gadget filesystem"
69 #define DRIVER_VERSION "24 Aug 2004"
70
71 static const char driver_desc [] = DRIVER_DESC;
72 static const char shortname [] = "gadgetfs";
73
74 MODULE_DESCRIPTION (DRIVER_DESC);
75 MODULE_AUTHOR ("David Brownell");
76 MODULE_LICENSE ("GPL");
77
78 static int ep_open(struct inode *, struct file *);
79
80
81 /*----------------------------------------------------------------------*/
82
83 #define GADGETFS_MAGIC 0xaee71ee7
84
85 /* /dev/gadget/$CHIP represents ep0 and the whole device */
86 enum ep0_state {
87 /* DISBLED is the initial state.
88 */
89 STATE_DEV_DISABLED = 0,
90
91 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
92 * ep0/device i/o modes and binding to the controller. Driver
93 * must always write descriptors to initialize the device, then
94 * the device becomes UNCONNECTED until enumeration.
95 */
96 STATE_DEV_OPENED,
97
98 /* From then on, ep0 fd is in either of two basic modes:
99 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
100 * - SETUP: read/write will transfer control data and succeed;
101 * or if "wrong direction", performs protocol stall
102 */
103 STATE_DEV_UNCONNECTED,
104 STATE_DEV_CONNECTED,
105 STATE_DEV_SETUP,
106
107 /* UNBOUND means the driver closed ep0, so the device won't be
108 * accessible again (DEV_DISABLED) until all fds are closed.
109 */
110 STATE_DEV_UNBOUND,
111 };
112
113 /* enough for the whole queue: most events invalidate others */
114 #define N_EVENT 5
115
116 struct dev_data {
117 spinlock_t lock;
118 atomic_t count;
119 enum ep0_state state; /* P: lock */
120 struct usb_gadgetfs_event event [N_EVENT];
121 unsigned ev_next;
122 struct fasync_struct *fasync;
123 u8 current_config;
124
125 /* drivers reading ep0 MUST handle control requests (SETUP)
126 * reported that way; else the host will time out.
127 */
128 unsigned usermode_setup : 1,
129 setup_in : 1,
130 setup_can_stall : 1,
131 setup_out_ready : 1,
132 setup_out_error : 1,
133 setup_abort : 1;
134 unsigned setup_wLength;
135
136 /* the rest is basically write-once */
137 struct usb_config_descriptor *config, *hs_config;
138 struct usb_device_descriptor *dev;
139 struct usb_request *req;
140 struct usb_gadget *gadget;
141 struct list_head epfiles;
142 void *buf;
143 wait_queue_head_t wait;
144 struct super_block *sb;
145 struct dentry *dentry;
146
147 /* except this scratch i/o buffer for ep0 */
148 u8 rbuf [256];
149 };
150
151 static inline void get_dev (struct dev_data *data)
152 {
153 atomic_inc (&data->count);
154 }
155
156 static void put_dev (struct dev_data *data)
157 {
158 if (likely (!atomic_dec_and_test (&data->count)))
159 return;
160 /* needs no more cleanup */
161 BUG_ON (waitqueue_active (&data->wait));
162 kfree (data);
163 }
164
165 static struct dev_data *dev_new (void)
166 {
167 struct dev_data *dev;
168
169 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
170 if (!dev)
171 return NULL;
172 dev->state = STATE_DEV_DISABLED;
173 atomic_set (&dev->count, 1);
174 spin_lock_init (&dev->lock);
175 INIT_LIST_HEAD (&dev->epfiles);
176 init_waitqueue_head (&dev->wait);
177 return dev;
178 }
179
180 /*----------------------------------------------------------------------*/
181
182 /* other /dev/gadget/$ENDPOINT files represent endpoints */
183 enum ep_state {
184 STATE_EP_DISABLED = 0,
185 STATE_EP_READY,
186 STATE_EP_ENABLED,
187 STATE_EP_UNBOUND,
188 };
189
190 struct ep_data {
191 struct mutex lock;
192 enum ep_state state;
193 atomic_t count;
194 struct dev_data *dev;
195 /* must hold dev->lock before accessing ep or req */
196 struct usb_ep *ep;
197 struct usb_request *req;
198 ssize_t status;
199 char name [16];
200 struct usb_endpoint_descriptor desc, hs_desc;
201 struct list_head epfiles;
202 wait_queue_head_t wait;
203 struct dentry *dentry;
204 };
205
206 static inline void get_ep (struct ep_data *data)
207 {
208 atomic_inc (&data->count);
209 }
210
211 static void put_ep (struct ep_data *data)
212 {
213 if (likely (!atomic_dec_and_test (&data->count)))
214 return;
215 put_dev (data->dev);
216 /* needs no more cleanup */
217 BUG_ON (!list_empty (&data->epfiles));
218 BUG_ON (waitqueue_active (&data->wait));
219 kfree (data);
220 }
221
222 /*----------------------------------------------------------------------*/
223
224 /* most "how to use the hardware" policy choices are in userspace:
225 * mapping endpoint roles (which the driver needs) to the capabilities
226 * which the usb controller has. most of those capabilities are exposed
227 * implicitly, starting with the driver name and then endpoint names.
228 */
229
230 static const char *CHIP;
231
232 /*----------------------------------------------------------------------*/
233
234 /* NOTE: don't use dev_printk calls before binding to the gadget
235 * at the end of ep0 configuration, or after unbind.
236 */
237
238 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
239 #define xprintk(d,level,fmt,args...) \
240 printk(level "%s: " fmt , shortname , ## args)
241
242 #ifdef DEBUG
243 #define DBG(dev,fmt,args...) \
244 xprintk(dev , KERN_DEBUG , fmt , ## args)
245 #else
246 #define DBG(dev,fmt,args...) \
247 do { } while (0)
248 #endif /* DEBUG */
249
250 #ifdef VERBOSE_DEBUG
251 #define VDEBUG DBG
252 #else
253 #define VDEBUG(dev,fmt,args...) \
254 do { } while (0)
255 #endif /* DEBUG */
256
257 #define ERROR(dev,fmt,args...) \
258 xprintk(dev , KERN_ERR , fmt , ## args)
259 #define INFO(dev,fmt,args...) \
260 xprintk(dev , KERN_INFO , fmt , ## args)
261
262
263 /*----------------------------------------------------------------------*/
264
265 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
266 *
267 * After opening, configure non-control endpoints. Then use normal
268 * stream read() and write() requests; and maybe ioctl() to get more
269 * precise FIFO status when recovering from cancellation.
270 */
271
272 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
273 {
274 struct ep_data *epdata = ep->driver_data;
275
276 if (!req->context)
277 return;
278 if (req->status)
279 epdata->status = req->status;
280 else
281 epdata->status = req->actual;
282 complete ((struct completion *)req->context);
283 }
284
285 /* tasklock endpoint, returning when it's connected.
286 * still need dev->lock to use epdata->ep.
287 */
288 static int
289 get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
290 {
291 int val;
292
293 if (f_flags & O_NONBLOCK) {
294 if (!mutex_trylock(&epdata->lock))
295 goto nonblock;
296 if (epdata->state != STATE_EP_ENABLED &&
297 (!is_write || epdata->state != STATE_EP_READY)) {
298 mutex_unlock(&epdata->lock);
299 nonblock:
300 val = -EAGAIN;
301 } else
302 val = 0;
303 return val;
304 }
305
306 val = mutex_lock_interruptible(&epdata->lock);
307 if (val < 0)
308 return val;
309
310 switch (epdata->state) {
311 case STATE_EP_ENABLED:
312 return 0;
313 case STATE_EP_READY: /* not configured yet */
314 if (is_write)
315 return 0;
316 // FALLTHRU
317 case STATE_EP_UNBOUND: /* clean disconnect */
318 break;
319 // case STATE_EP_DISABLED: /* "can't happen" */
320 default: /* error! */
321 pr_debug ("%s: ep %p not available, state %d\n",
322 shortname, epdata, epdata->state);
323 }
324 mutex_unlock(&epdata->lock);
325 return -ENODEV;
326 }
327
328 static ssize_t
329 ep_io (struct ep_data *epdata, void *buf, unsigned len)
330 {
331 DECLARE_COMPLETION_ONSTACK (done);
332 int value;
333
334 spin_lock_irq (&epdata->dev->lock);
335 if (likely (epdata->ep != NULL)) {
336 struct usb_request *req = epdata->req;
337
338 req->context = &done;
339 req->complete = epio_complete;
340 req->buf = buf;
341 req->length = len;
342 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
343 } else
344 value = -ENODEV;
345 spin_unlock_irq (&epdata->dev->lock);
346
347 if (likely (value == 0)) {
348 value = wait_event_interruptible (done.wait, done.done);
349 if (value != 0) {
350 spin_lock_irq (&epdata->dev->lock);
351 if (likely (epdata->ep != NULL)) {
352 DBG (epdata->dev, "%s i/o interrupted\n",
353 epdata->name);
354 usb_ep_dequeue (epdata->ep, epdata->req);
355 spin_unlock_irq (&epdata->dev->lock);
356
357 wait_event (done.wait, done.done);
358 if (epdata->status == -ECONNRESET)
359 epdata->status = -EINTR;
360 } else {
361 spin_unlock_irq (&epdata->dev->lock);
362
363 DBG (epdata->dev, "endpoint gone\n");
364 epdata->status = -ENODEV;
365 }
366 }
367 return epdata->status;
368 }
369 return value;
370 }
371
372 static int
373 ep_release (struct inode *inode, struct file *fd)
374 {
375 struct ep_data *data = fd->private_data;
376 int value;
377
378 value = mutex_lock_interruptible(&data->lock);
379 if (value < 0)
380 return value;
381
382 /* clean up if this can be reopened */
383 if (data->state != STATE_EP_UNBOUND) {
384 data->state = STATE_EP_DISABLED;
385 data->desc.bDescriptorType = 0;
386 data->hs_desc.bDescriptorType = 0;
387 usb_ep_disable(data->ep);
388 }
389 mutex_unlock(&data->lock);
390 put_ep (data);
391 return 0;
392 }
393
394 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
395 {
396 struct ep_data *data = fd->private_data;
397 int status;
398
399 if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
400 return status;
401
402 spin_lock_irq (&data->dev->lock);
403 if (likely (data->ep != NULL)) {
404 switch (code) {
405 case GADGETFS_FIFO_STATUS:
406 status = usb_ep_fifo_status (data->ep);
407 break;
408 case GADGETFS_FIFO_FLUSH:
409 usb_ep_fifo_flush (data->ep);
410 break;
411 case GADGETFS_CLEAR_HALT:
412 status = usb_ep_clear_halt (data->ep);
413 break;
414 default:
415 status = -ENOTTY;
416 }
417 } else
418 status = -ENODEV;
419 spin_unlock_irq (&data->dev->lock);
420 mutex_unlock(&data->lock);
421 return status;
422 }
423
424 /*----------------------------------------------------------------------*/
425
426 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
427
428 struct kiocb_priv {
429 struct usb_request *req;
430 struct ep_data *epdata;
431 struct kiocb *iocb;
432 struct mm_struct *mm;
433 struct work_struct work;
434 void *buf;
435 struct iov_iter to;
436 const void *to_free;
437 unsigned actual;
438 };
439
440 static int ep_aio_cancel(struct kiocb *iocb)
441 {
442 struct kiocb_priv *priv = iocb->private;
443 struct ep_data *epdata;
444 int value;
445
446 local_irq_disable();
447 epdata = priv->epdata;
448 // spin_lock(&epdata->dev->lock);
449 if (likely(epdata && epdata->ep && priv->req))
450 value = usb_ep_dequeue (epdata->ep, priv->req);
451 else
452 value = -EINVAL;
453 // spin_unlock(&epdata->dev->lock);
454 local_irq_enable();
455
456 return value;
457 }
458
459 static void ep_user_copy_worker(struct work_struct *work)
460 {
461 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
462 struct mm_struct *mm = priv->mm;
463 struct kiocb *iocb = priv->iocb;
464 size_t ret;
465
466 use_mm(mm);
467 ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
468 unuse_mm(mm);
469 if (!ret)
470 ret = -EFAULT;
471
472 /* completing the iocb can drop the ctx and mm, don't touch mm after */
473 iocb->ki_complete(iocb, ret, ret);
474
475 kfree(priv->buf);
476 kfree(priv->to_free);
477 kfree(priv);
478 }
479
480 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
481 {
482 struct kiocb *iocb = req->context;
483 struct kiocb_priv *priv = iocb->private;
484 struct ep_data *epdata = priv->epdata;
485
486 /* lock against disconnect (and ideally, cancel) */
487 spin_lock(&epdata->dev->lock);
488 priv->req = NULL;
489 priv->epdata = NULL;
490
491 /* if this was a write or a read returning no data then we
492 * don't need to copy anything to userspace, so we can
493 * complete the aio request immediately.
494 */
495 if (priv->to_free == NULL || unlikely(req->actual == 0)) {
496 kfree(req->buf);
497 kfree(priv->to_free);
498 kfree(priv);
499 iocb->private = NULL;
500 /* aio_complete() reports bytes-transferred _and_ faults */
501
502 iocb->ki_complete(iocb, req->actual ? req->actual : req->status,
503 req->status);
504 } else {
505 /* ep_copy_to_user() won't report both; we hide some faults */
506 if (unlikely(0 != req->status))
507 DBG(epdata->dev, "%s fault %d len %d\n",
508 ep->name, req->status, req->actual);
509
510 priv->buf = req->buf;
511 priv->actual = req->actual;
512 INIT_WORK(&priv->work, ep_user_copy_worker);
513 schedule_work(&priv->work);
514 }
515 spin_unlock(&epdata->dev->lock);
516
517 usb_ep_free_request(ep, req);
518 put_ep(epdata);
519 }
520
521 static ssize_t ep_aio(struct kiocb *iocb,
522 struct kiocb_priv *priv,
523 struct ep_data *epdata,
524 char *buf,
525 size_t len)
526 {
527 struct usb_request *req;
528 ssize_t value;
529
530 iocb->private = priv;
531 priv->iocb = iocb;
532
533 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
534 get_ep(epdata);
535 priv->epdata = epdata;
536 priv->actual = 0;
537 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
538
539 /* each kiocb is coupled to one usb_request, but we can't
540 * allocate or submit those if the host disconnected.
541 */
542 spin_lock_irq(&epdata->dev->lock);
543 value = -ENODEV;
544 if (unlikely(epdata->ep))
545 goto fail;
546
547 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
548 value = -ENOMEM;
549 if (unlikely(!req))
550 goto fail;
551
552 priv->req = req;
553 req->buf = buf;
554 req->length = len;
555 req->complete = ep_aio_complete;
556 req->context = iocb;
557 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
558 if (unlikely(0 != value)) {
559 usb_ep_free_request(epdata->ep, req);
560 goto fail;
561 }
562 spin_unlock_irq(&epdata->dev->lock);
563 return -EIOCBQUEUED;
564
565 fail:
566 spin_unlock_irq(&epdata->dev->lock);
567 kfree(priv->to_free);
568 kfree(priv);
569 put_ep(epdata);
570 return value;
571 }
572
573 static ssize_t
574 ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
575 {
576 struct file *file = iocb->ki_filp;
577 struct ep_data *epdata = file->private_data;
578 size_t len = iov_iter_count(to);
579 ssize_t value;
580 char *buf;
581
582 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
583 return value;
584
585 /* halt any endpoint by doing a "wrong direction" i/o call */
586 if (usb_endpoint_dir_in(&epdata->desc)) {
587 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
588 !is_sync_kiocb(iocb)) {
589 mutex_unlock(&epdata->lock);
590 return -EINVAL;
591 }
592 DBG (epdata->dev, "%s halt\n", epdata->name);
593 spin_lock_irq(&epdata->dev->lock);
594 if (likely(epdata->ep != NULL))
595 usb_ep_set_halt(epdata->ep);
596 spin_unlock_irq(&epdata->dev->lock);
597 mutex_unlock(&epdata->lock);
598 return -EBADMSG;
599 }
600
601 buf = kmalloc(len, GFP_KERNEL);
602 if (unlikely(!buf)) {
603 mutex_unlock(&epdata->lock);
604 return -ENOMEM;
605 }
606 if (is_sync_kiocb(iocb)) {
607 value = ep_io(epdata, buf, len);
608 if (value >= 0 && copy_to_iter(buf, value, to))
609 value = -EFAULT;
610 } else {
611 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
612 value = -ENOMEM;
613 if (!priv)
614 goto fail;
615 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
616 if (!priv->to_free) {
617 kfree(priv);
618 goto fail;
619 }
620 value = ep_aio(iocb, priv, epdata, buf, len);
621 if (value == -EIOCBQUEUED)
622 buf = NULL;
623 }
624 fail:
625 kfree(buf);
626 mutex_unlock(&epdata->lock);
627 return value;
628 }
629
630 static ssize_t ep_config(struct ep_data *, const char *, size_t);
631
632 static ssize_t
633 ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
634 {
635 struct file *file = iocb->ki_filp;
636 struct ep_data *epdata = file->private_data;
637 size_t len = iov_iter_count(from);
638 bool configured;
639 ssize_t value;
640 char *buf;
641
642 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
643 return value;
644
645 configured = epdata->state == STATE_EP_ENABLED;
646
647 /* halt any endpoint by doing a "wrong direction" i/o call */
648 if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
649 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
650 !is_sync_kiocb(iocb)) {
651 mutex_unlock(&epdata->lock);
652 return -EINVAL;
653 }
654 DBG (epdata->dev, "%s halt\n", epdata->name);
655 spin_lock_irq(&epdata->dev->lock);
656 if (likely(epdata->ep != NULL))
657 usb_ep_set_halt(epdata->ep);
658 spin_unlock_irq(&epdata->dev->lock);
659 mutex_unlock(&epdata->lock);
660 return -EBADMSG;
661 }
662
663 buf = kmalloc(len, GFP_KERNEL);
664 if (unlikely(!buf)) {
665 mutex_unlock(&epdata->lock);
666 return -ENOMEM;
667 }
668
669 if (unlikely(copy_from_iter(buf, len, from) != len)) {
670 value = -EFAULT;
671 goto out;
672 }
673
674 if (unlikely(!configured)) {
675 value = ep_config(epdata, buf, len);
676 } else if (is_sync_kiocb(iocb)) {
677 value = ep_io(epdata, buf, len);
678 } else {
679 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
680 value = -ENOMEM;
681 if (priv) {
682 value = ep_aio(iocb, priv, epdata, buf, len);
683 if (value == -EIOCBQUEUED)
684 buf = NULL;
685 }
686 }
687 out:
688 kfree(buf);
689 mutex_unlock(&epdata->lock);
690 return value;
691 }
692
693 /*----------------------------------------------------------------------*/
694
695 /* used after endpoint configuration */
696 static const struct file_operations ep_io_operations = {
697 .owner = THIS_MODULE,
698
699 .open = ep_open,
700 .release = ep_release,
701 .llseek = no_llseek,
702 .read = new_sync_read,
703 .write = new_sync_write,
704 .unlocked_ioctl = ep_ioctl,
705 .read_iter = ep_read_iter,
706 .write_iter = ep_write_iter,
707 };
708
709 /* ENDPOINT INITIALIZATION
710 *
711 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
712 * status = write (fd, descriptors, sizeof descriptors)
713 *
714 * That write establishes the endpoint configuration, configuring
715 * the controller to process bulk, interrupt, or isochronous transfers
716 * at the right maxpacket size, and so on.
717 *
718 * The descriptors are message type 1, identified by a host order u32
719 * at the beginning of what's written. Descriptor order is: full/low
720 * speed descriptor, then optional high speed descriptor.
721 */
722 static ssize_t
723 ep_config (struct ep_data *data, const char *buf, size_t len)
724 {
725 struct usb_ep *ep;
726 u32 tag;
727 int value, length = len;
728
729 if (data->state != STATE_EP_READY) {
730 value = -EL2HLT;
731 goto fail;
732 }
733
734 value = len;
735 if (len < USB_DT_ENDPOINT_SIZE + 4)
736 goto fail0;
737
738 /* we might need to change message format someday */
739 memcpy(&tag, buf, 4);
740 if (tag != 1) {
741 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
742 goto fail0;
743 }
744 buf += 4;
745 len -= 4;
746
747 /* NOTE: audio endpoint extensions not accepted here;
748 * just don't include the extra bytes.
749 */
750
751 /* full/low speed descriptor, then high speed */
752 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
753 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
754 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
755 goto fail0;
756 if (len != USB_DT_ENDPOINT_SIZE) {
757 if (len != 2 * USB_DT_ENDPOINT_SIZE)
758 goto fail0;
759 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
760 USB_DT_ENDPOINT_SIZE);
761 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
762 || data->hs_desc.bDescriptorType
763 != USB_DT_ENDPOINT) {
764 DBG(data->dev, "config %s, bad hs length or type\n",
765 data->name);
766 goto fail0;
767 }
768 }
769
770 spin_lock_irq (&data->dev->lock);
771 if (data->dev->state == STATE_DEV_UNBOUND) {
772 value = -ENOENT;
773 goto gone;
774 } else if ((ep = data->ep) == NULL) {
775 value = -ENODEV;
776 goto gone;
777 }
778 switch (data->dev->gadget->speed) {
779 case USB_SPEED_LOW:
780 case USB_SPEED_FULL:
781 ep->desc = &data->desc;
782 break;
783 case USB_SPEED_HIGH:
784 /* fails if caller didn't provide that descriptor... */
785 ep->desc = &data->hs_desc;
786 break;
787 default:
788 DBG(data->dev, "unconnected, %s init abandoned\n",
789 data->name);
790 value = -EINVAL;
791 goto gone;
792 }
793 value = usb_ep_enable(ep);
794 if (value == 0) {
795 data->state = STATE_EP_ENABLED;
796 value = length;
797 }
798 gone:
799 spin_unlock_irq (&data->dev->lock);
800 if (value < 0) {
801 fail:
802 data->desc.bDescriptorType = 0;
803 data->hs_desc.bDescriptorType = 0;
804 }
805 return value;
806 fail0:
807 value = -EINVAL;
808 goto fail;
809 }
810
811 static int
812 ep_open (struct inode *inode, struct file *fd)
813 {
814 struct ep_data *data = inode->i_private;
815 int value = -EBUSY;
816
817 if (mutex_lock_interruptible(&data->lock) != 0)
818 return -EINTR;
819 spin_lock_irq (&data->dev->lock);
820 if (data->dev->state == STATE_DEV_UNBOUND)
821 value = -ENOENT;
822 else if (data->state == STATE_EP_DISABLED) {
823 value = 0;
824 data->state = STATE_EP_READY;
825 get_ep (data);
826 fd->private_data = data;
827 VDEBUG (data->dev, "%s ready\n", data->name);
828 } else
829 DBG (data->dev, "%s state %d\n",
830 data->name, data->state);
831 spin_unlock_irq (&data->dev->lock);
832 mutex_unlock(&data->lock);
833 return value;
834 }
835
836 /*----------------------------------------------------------------------*/
837
838 /* EP0 IMPLEMENTATION can be partly in userspace.
839 *
840 * Drivers that use this facility receive various events, including
841 * control requests the kernel doesn't handle. Drivers that don't
842 * use this facility may be too simple-minded for real applications.
843 */
844
845 static inline void ep0_readable (struct dev_data *dev)
846 {
847 wake_up (&dev->wait);
848 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
849 }
850
851 static void clean_req (struct usb_ep *ep, struct usb_request *req)
852 {
853 struct dev_data *dev = ep->driver_data;
854
855 if (req->buf != dev->rbuf) {
856 kfree(req->buf);
857 req->buf = dev->rbuf;
858 }
859 req->complete = epio_complete;
860 dev->setup_out_ready = 0;
861 }
862
863 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
864 {
865 struct dev_data *dev = ep->driver_data;
866 unsigned long flags;
867 int free = 1;
868
869 /* for control OUT, data must still get to userspace */
870 spin_lock_irqsave(&dev->lock, flags);
871 if (!dev->setup_in) {
872 dev->setup_out_error = (req->status != 0);
873 if (!dev->setup_out_error)
874 free = 0;
875 dev->setup_out_ready = 1;
876 ep0_readable (dev);
877 }
878
879 /* clean up as appropriate */
880 if (free && req->buf != &dev->rbuf)
881 clean_req (ep, req);
882 req->complete = epio_complete;
883 spin_unlock_irqrestore(&dev->lock, flags);
884 }
885
886 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
887 {
888 struct dev_data *dev = ep->driver_data;
889
890 if (dev->setup_out_ready) {
891 DBG (dev, "ep0 request busy!\n");
892 return -EBUSY;
893 }
894 if (len > sizeof (dev->rbuf))
895 req->buf = kmalloc(len, GFP_ATOMIC);
896 if (req->buf == NULL) {
897 req->buf = dev->rbuf;
898 return -ENOMEM;
899 }
900 req->complete = ep0_complete;
901 req->length = len;
902 req->zero = 0;
903 return 0;
904 }
905
906 static ssize_t
907 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
908 {
909 struct dev_data *dev = fd->private_data;
910 ssize_t retval;
911 enum ep0_state state;
912
913 spin_lock_irq (&dev->lock);
914 if (dev->state <= STATE_DEV_OPENED) {
915 retval = -EINVAL;
916 goto done;
917 }
918
919 /* report fd mode change before acting on it */
920 if (dev->setup_abort) {
921 dev->setup_abort = 0;
922 retval = -EIDRM;
923 goto done;
924 }
925
926 /* control DATA stage */
927 if ((state = dev->state) == STATE_DEV_SETUP) {
928
929 if (dev->setup_in) { /* stall IN */
930 VDEBUG(dev, "ep0in stall\n");
931 (void) usb_ep_set_halt (dev->gadget->ep0);
932 retval = -EL2HLT;
933 dev->state = STATE_DEV_CONNECTED;
934
935 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
936 struct usb_ep *ep = dev->gadget->ep0;
937 struct usb_request *req = dev->req;
938
939 if ((retval = setup_req (ep, req, 0)) == 0)
940 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
941 dev->state = STATE_DEV_CONNECTED;
942
943 /* assume that was SET_CONFIGURATION */
944 if (dev->current_config) {
945 unsigned power;
946
947 if (gadget_is_dualspeed(dev->gadget)
948 && (dev->gadget->speed
949 == USB_SPEED_HIGH))
950 power = dev->hs_config->bMaxPower;
951 else
952 power = dev->config->bMaxPower;
953 usb_gadget_vbus_draw(dev->gadget, 2 * power);
954 }
955
956 } else { /* collect OUT data */
957 if ((fd->f_flags & O_NONBLOCK) != 0
958 && !dev->setup_out_ready) {
959 retval = -EAGAIN;
960 goto done;
961 }
962 spin_unlock_irq (&dev->lock);
963 retval = wait_event_interruptible (dev->wait,
964 dev->setup_out_ready != 0);
965
966 /* FIXME state could change from under us */
967 spin_lock_irq (&dev->lock);
968 if (retval)
969 goto done;
970
971 if (dev->state != STATE_DEV_SETUP) {
972 retval = -ECANCELED;
973 goto done;
974 }
975 dev->state = STATE_DEV_CONNECTED;
976
977 if (dev->setup_out_error)
978 retval = -EIO;
979 else {
980 len = min (len, (size_t)dev->req->actual);
981 // FIXME don't call this with the spinlock held ...
982 if (copy_to_user (buf, dev->req->buf, len))
983 retval = -EFAULT;
984 else
985 retval = len;
986 clean_req (dev->gadget->ep0, dev->req);
987 /* NOTE userspace can't yet choose to stall */
988 }
989 }
990 goto done;
991 }
992
993 /* else normal: return event data */
994 if (len < sizeof dev->event [0]) {
995 retval = -EINVAL;
996 goto done;
997 }
998 len -= len % sizeof (struct usb_gadgetfs_event);
999 dev->usermode_setup = 1;
1000
1001 scan:
1002 /* return queued events right away */
1003 if (dev->ev_next != 0) {
1004 unsigned i, n;
1005
1006 n = len / sizeof (struct usb_gadgetfs_event);
1007 if (dev->ev_next < n)
1008 n = dev->ev_next;
1009
1010 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1011 for (i = 0; i < n; i++) {
1012 if (dev->event [i].type == GADGETFS_SETUP) {
1013 dev->state = STATE_DEV_SETUP;
1014 n = i + 1;
1015 break;
1016 }
1017 }
1018 spin_unlock_irq (&dev->lock);
1019 len = n * sizeof (struct usb_gadgetfs_event);
1020 if (copy_to_user (buf, &dev->event, len))
1021 retval = -EFAULT;
1022 else
1023 retval = len;
1024 if (len > 0) {
1025 /* NOTE this doesn't guard against broken drivers;
1026 * concurrent ep0 readers may lose events.
1027 */
1028 spin_lock_irq (&dev->lock);
1029 if (dev->ev_next > n) {
1030 memmove(&dev->event[0], &dev->event[n],
1031 sizeof (struct usb_gadgetfs_event)
1032 * (dev->ev_next - n));
1033 }
1034 dev->ev_next -= n;
1035 spin_unlock_irq (&dev->lock);
1036 }
1037 return retval;
1038 }
1039 if (fd->f_flags & O_NONBLOCK) {
1040 retval = -EAGAIN;
1041 goto done;
1042 }
1043
1044 switch (state) {
1045 default:
1046 DBG (dev, "fail %s, state %d\n", __func__, state);
1047 retval = -ESRCH;
1048 break;
1049 case STATE_DEV_UNCONNECTED:
1050 case STATE_DEV_CONNECTED:
1051 spin_unlock_irq (&dev->lock);
1052 DBG (dev, "%s wait\n", __func__);
1053
1054 /* wait for events */
1055 retval = wait_event_interruptible (dev->wait,
1056 dev->ev_next != 0);
1057 if (retval < 0)
1058 return retval;
1059 spin_lock_irq (&dev->lock);
1060 goto scan;
1061 }
1062
1063 done:
1064 spin_unlock_irq (&dev->lock);
1065 return retval;
1066 }
1067
1068 static struct usb_gadgetfs_event *
1069 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1070 {
1071 struct usb_gadgetfs_event *event;
1072 unsigned i;
1073
1074 switch (type) {
1075 /* these events purge the queue */
1076 case GADGETFS_DISCONNECT:
1077 if (dev->state == STATE_DEV_SETUP)
1078 dev->setup_abort = 1;
1079 // FALL THROUGH
1080 case GADGETFS_CONNECT:
1081 dev->ev_next = 0;
1082 break;
1083 case GADGETFS_SETUP: /* previous request timed out */
1084 case GADGETFS_SUSPEND: /* same effect */
1085 /* these events can't be repeated */
1086 for (i = 0; i != dev->ev_next; i++) {
1087 if (dev->event [i].type != type)
1088 continue;
1089 DBG(dev, "discard old event[%d] %d\n", i, type);
1090 dev->ev_next--;
1091 if (i == dev->ev_next)
1092 break;
1093 /* indices start at zero, for simplicity */
1094 memmove (&dev->event [i], &dev->event [i + 1],
1095 sizeof (struct usb_gadgetfs_event)
1096 * (dev->ev_next - i));
1097 }
1098 break;
1099 default:
1100 BUG ();
1101 }
1102 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1103 event = &dev->event [dev->ev_next++];
1104 BUG_ON (dev->ev_next > N_EVENT);
1105 memset (event, 0, sizeof *event);
1106 event->type = type;
1107 return event;
1108 }
1109
1110 static ssize_t
1111 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1112 {
1113 struct dev_data *dev = fd->private_data;
1114 ssize_t retval = -ESRCH;
1115
1116 /* report fd mode change before acting on it */
1117 if (dev->setup_abort) {
1118 dev->setup_abort = 0;
1119 retval = -EIDRM;
1120
1121 /* data and/or status stage for control request */
1122 } else if (dev->state == STATE_DEV_SETUP) {
1123
1124 /* IN DATA+STATUS caller makes len <= wLength */
1125 if (dev->setup_in) {
1126 retval = setup_req (dev->gadget->ep0, dev->req, len);
1127 if (retval == 0) {
1128 dev->state = STATE_DEV_CONNECTED;
1129 spin_unlock_irq (&dev->lock);
1130 if (copy_from_user (dev->req->buf, buf, len))
1131 retval = -EFAULT;
1132 else {
1133 if (len < dev->setup_wLength)
1134 dev->req->zero = 1;
1135 retval = usb_ep_queue (
1136 dev->gadget->ep0, dev->req,
1137 GFP_KERNEL);
1138 }
1139 if (retval < 0) {
1140 spin_lock_irq (&dev->lock);
1141 clean_req (dev->gadget->ep0, dev->req);
1142 spin_unlock_irq (&dev->lock);
1143 } else
1144 retval = len;
1145
1146 return retval;
1147 }
1148
1149 /* can stall some OUT transfers */
1150 } else if (dev->setup_can_stall) {
1151 VDEBUG(dev, "ep0out stall\n");
1152 (void) usb_ep_set_halt (dev->gadget->ep0);
1153 retval = -EL2HLT;
1154 dev->state = STATE_DEV_CONNECTED;
1155 } else {
1156 DBG(dev, "bogus ep0out stall!\n");
1157 }
1158 } else
1159 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1160
1161 return retval;
1162 }
1163
1164 static int
1165 ep0_fasync (int f, struct file *fd, int on)
1166 {
1167 struct dev_data *dev = fd->private_data;
1168 // caller must F_SETOWN before signal delivery happens
1169 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1170 return fasync_helper (f, fd, on, &dev->fasync);
1171 }
1172
1173 static struct usb_gadget_driver gadgetfs_driver;
1174
1175 static int
1176 dev_release (struct inode *inode, struct file *fd)
1177 {
1178 struct dev_data *dev = fd->private_data;
1179
1180 /* closing ep0 === shutdown all */
1181
1182 usb_gadget_unregister_driver (&gadgetfs_driver);
1183
1184 /* at this point "good" hardware has disconnected the
1185 * device from USB; the host won't see it any more.
1186 * alternatively, all host requests will time out.
1187 */
1188
1189 kfree (dev->buf);
1190 dev->buf = NULL;
1191
1192 /* other endpoints were all decoupled from this device */
1193 spin_lock_irq(&dev->lock);
1194 dev->state = STATE_DEV_DISABLED;
1195 spin_unlock_irq(&dev->lock);
1196
1197 put_dev (dev);
1198 return 0;
1199 }
1200
1201 static unsigned int
1202 ep0_poll (struct file *fd, poll_table *wait)
1203 {
1204 struct dev_data *dev = fd->private_data;
1205 int mask = 0;
1206
1207 if (dev->state <= STATE_DEV_OPENED)
1208 return DEFAULT_POLLMASK;
1209
1210 poll_wait(fd, &dev->wait, wait);
1211
1212 spin_lock_irq (&dev->lock);
1213
1214 /* report fd mode change before acting on it */
1215 if (dev->setup_abort) {
1216 dev->setup_abort = 0;
1217 mask = POLLHUP;
1218 goto out;
1219 }
1220
1221 if (dev->state == STATE_DEV_SETUP) {
1222 if (dev->setup_in || dev->setup_can_stall)
1223 mask = POLLOUT;
1224 } else {
1225 if (dev->ev_next != 0)
1226 mask = POLLIN;
1227 }
1228 out:
1229 spin_unlock_irq(&dev->lock);
1230 return mask;
1231 }
1232
1233 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1234 {
1235 struct dev_data *dev = fd->private_data;
1236 struct usb_gadget *gadget = dev->gadget;
1237 long ret = -ENOTTY;
1238
1239 if (gadget->ops->ioctl)
1240 ret = gadget->ops->ioctl (gadget, code, value);
1241
1242 return ret;
1243 }
1244
1245 /*----------------------------------------------------------------------*/
1246
1247 /* The in-kernel gadget driver handles most ep0 issues, in particular
1248 * enumerating the single configuration (as provided from user space).
1249 *
1250 * Unrecognized ep0 requests may be handled in user space.
1251 */
1252
1253 static void make_qualifier (struct dev_data *dev)
1254 {
1255 struct usb_qualifier_descriptor qual;
1256 struct usb_device_descriptor *desc;
1257
1258 qual.bLength = sizeof qual;
1259 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1260 qual.bcdUSB = cpu_to_le16 (0x0200);
1261
1262 desc = dev->dev;
1263 qual.bDeviceClass = desc->bDeviceClass;
1264 qual.bDeviceSubClass = desc->bDeviceSubClass;
1265 qual.bDeviceProtocol = desc->bDeviceProtocol;
1266
1267 /* assumes ep0 uses the same value for both speeds ... */
1268 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1269
1270 qual.bNumConfigurations = 1;
1271 qual.bRESERVED = 0;
1272
1273 memcpy (dev->rbuf, &qual, sizeof qual);
1274 }
1275
1276 static int
1277 config_buf (struct dev_data *dev, u8 type, unsigned index)
1278 {
1279 int len;
1280 int hs = 0;
1281
1282 /* only one configuration */
1283 if (index > 0)
1284 return -EINVAL;
1285
1286 if (gadget_is_dualspeed(dev->gadget)) {
1287 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1288 if (type == USB_DT_OTHER_SPEED_CONFIG)
1289 hs = !hs;
1290 }
1291 if (hs) {
1292 dev->req->buf = dev->hs_config;
1293 len = le16_to_cpu(dev->hs_config->wTotalLength);
1294 } else {
1295 dev->req->buf = dev->config;
1296 len = le16_to_cpu(dev->config->wTotalLength);
1297 }
1298 ((u8 *)dev->req->buf) [1] = type;
1299 return len;
1300 }
1301
1302 static int
1303 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1304 {
1305 struct dev_data *dev = get_gadget_data (gadget);
1306 struct usb_request *req = dev->req;
1307 int value = -EOPNOTSUPP;
1308 struct usb_gadgetfs_event *event;
1309 u16 w_value = le16_to_cpu(ctrl->wValue);
1310 u16 w_length = le16_to_cpu(ctrl->wLength);
1311
1312 spin_lock (&dev->lock);
1313 dev->setup_abort = 0;
1314 if (dev->state == STATE_DEV_UNCONNECTED) {
1315 if (gadget_is_dualspeed(gadget)
1316 && gadget->speed == USB_SPEED_HIGH
1317 && dev->hs_config == NULL) {
1318 spin_unlock(&dev->lock);
1319 ERROR (dev, "no high speed config??\n");
1320 return -EINVAL;
1321 }
1322
1323 dev->state = STATE_DEV_CONNECTED;
1324
1325 INFO (dev, "connected\n");
1326 event = next_event (dev, GADGETFS_CONNECT);
1327 event->u.speed = gadget->speed;
1328 ep0_readable (dev);
1329
1330 /* host may have given up waiting for response. we can miss control
1331 * requests handled lower down (device/endpoint status and features);
1332 * then ep0_{read,write} will report the wrong status. controller
1333 * driver will have aborted pending i/o.
1334 */
1335 } else if (dev->state == STATE_DEV_SETUP)
1336 dev->setup_abort = 1;
1337
1338 req->buf = dev->rbuf;
1339 req->context = NULL;
1340 value = -EOPNOTSUPP;
1341 switch (ctrl->bRequest) {
1342
1343 case USB_REQ_GET_DESCRIPTOR:
1344 if (ctrl->bRequestType != USB_DIR_IN)
1345 goto unrecognized;
1346 switch (w_value >> 8) {
1347
1348 case USB_DT_DEVICE:
1349 value = min (w_length, (u16) sizeof *dev->dev);
1350 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1351 req->buf = dev->dev;
1352 break;
1353 case USB_DT_DEVICE_QUALIFIER:
1354 if (!dev->hs_config)
1355 break;
1356 value = min (w_length, (u16)
1357 sizeof (struct usb_qualifier_descriptor));
1358 make_qualifier (dev);
1359 break;
1360 case USB_DT_OTHER_SPEED_CONFIG:
1361 // FALLTHROUGH
1362 case USB_DT_CONFIG:
1363 value = config_buf (dev,
1364 w_value >> 8,
1365 w_value & 0xff);
1366 if (value >= 0)
1367 value = min (w_length, (u16) value);
1368 break;
1369 case USB_DT_STRING:
1370 goto unrecognized;
1371
1372 default: // all others are errors
1373 break;
1374 }
1375 break;
1376
1377 /* currently one config, two speeds */
1378 case USB_REQ_SET_CONFIGURATION:
1379 if (ctrl->bRequestType != 0)
1380 goto unrecognized;
1381 if (0 == (u8) w_value) {
1382 value = 0;
1383 dev->current_config = 0;
1384 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1385 // user mode expected to disable endpoints
1386 } else {
1387 u8 config, power;
1388
1389 if (gadget_is_dualspeed(gadget)
1390 && gadget->speed == USB_SPEED_HIGH) {
1391 config = dev->hs_config->bConfigurationValue;
1392 power = dev->hs_config->bMaxPower;
1393 } else {
1394 config = dev->config->bConfigurationValue;
1395 power = dev->config->bMaxPower;
1396 }
1397
1398 if (config == (u8) w_value) {
1399 value = 0;
1400 dev->current_config = config;
1401 usb_gadget_vbus_draw(gadget, 2 * power);
1402 }
1403 }
1404
1405 /* report SET_CONFIGURATION like any other control request,
1406 * except that usermode may not stall this. the next
1407 * request mustn't be allowed start until this finishes:
1408 * endpoints and threads set up, etc.
1409 *
1410 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1411 * has bad/racey automagic that prevents synchronizing here.
1412 * even kernel mode drivers often miss them.
1413 */
1414 if (value == 0) {
1415 INFO (dev, "configuration #%d\n", dev->current_config);
1416 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1417 if (dev->usermode_setup) {
1418 dev->setup_can_stall = 0;
1419 goto delegate;
1420 }
1421 }
1422 break;
1423
1424 #ifndef CONFIG_USB_PXA25X
1425 /* PXA automagically handles this request too */
1426 case USB_REQ_GET_CONFIGURATION:
1427 if (ctrl->bRequestType != 0x80)
1428 goto unrecognized;
1429 *(u8 *)req->buf = dev->current_config;
1430 value = min (w_length, (u16) 1);
1431 break;
1432 #endif
1433
1434 default:
1435 unrecognized:
1436 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1437 dev->usermode_setup ? "delegate" : "fail",
1438 ctrl->bRequestType, ctrl->bRequest,
1439 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1440
1441 /* if there's an ep0 reader, don't stall */
1442 if (dev->usermode_setup) {
1443 dev->setup_can_stall = 1;
1444 delegate:
1445 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1446 ? 1 : 0;
1447 dev->setup_wLength = w_length;
1448 dev->setup_out_ready = 0;
1449 dev->setup_out_error = 0;
1450 value = 0;
1451
1452 /* read DATA stage for OUT right away */
1453 if (unlikely (!dev->setup_in && w_length)) {
1454 value = setup_req (gadget->ep0, dev->req,
1455 w_length);
1456 if (value < 0)
1457 break;
1458 value = usb_ep_queue (gadget->ep0, dev->req,
1459 GFP_ATOMIC);
1460 if (value < 0) {
1461 clean_req (gadget->ep0, dev->req);
1462 break;
1463 }
1464
1465 /* we can't currently stall these */
1466 dev->setup_can_stall = 0;
1467 }
1468
1469 /* state changes when reader collects event */
1470 event = next_event (dev, GADGETFS_SETUP);
1471 event->u.setup = *ctrl;
1472 ep0_readable (dev);
1473 spin_unlock (&dev->lock);
1474 return 0;
1475 }
1476 }
1477
1478 /* proceed with data transfer and status phases? */
1479 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1480 req->length = value;
1481 req->zero = value < w_length;
1482 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1483 if (value < 0) {
1484 DBG (dev, "ep_queue --> %d\n", value);
1485 req->status = 0;
1486 }
1487 }
1488
1489 /* device stalls when value < 0 */
1490 spin_unlock (&dev->lock);
1491 return value;
1492 }
1493
1494 static void destroy_ep_files (struct dev_data *dev)
1495 {
1496 DBG (dev, "%s %d\n", __func__, dev->state);
1497
1498 /* dev->state must prevent interference */
1499 spin_lock_irq (&dev->lock);
1500 while (!list_empty(&dev->epfiles)) {
1501 struct ep_data *ep;
1502 struct inode *parent;
1503 struct dentry *dentry;
1504
1505 /* break link to FS */
1506 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1507 list_del_init (&ep->epfiles);
1508 dentry = ep->dentry;
1509 ep->dentry = NULL;
1510 parent = dentry->d_parent->d_inode;
1511
1512 /* break link to controller */
1513 if (ep->state == STATE_EP_ENABLED)
1514 (void) usb_ep_disable (ep->ep);
1515 ep->state = STATE_EP_UNBOUND;
1516 usb_ep_free_request (ep->ep, ep->req);
1517 ep->ep = NULL;
1518 wake_up (&ep->wait);
1519 put_ep (ep);
1520
1521 spin_unlock_irq (&dev->lock);
1522
1523 /* break link to dcache */
1524 mutex_lock (&parent->i_mutex);
1525 d_delete (dentry);
1526 dput (dentry);
1527 mutex_unlock (&parent->i_mutex);
1528
1529 spin_lock_irq (&dev->lock);
1530 }
1531 spin_unlock_irq (&dev->lock);
1532 }
1533
1534
1535 static struct dentry *
1536 gadgetfs_create_file (struct super_block *sb, char const *name,
1537 void *data, const struct file_operations *fops);
1538
1539 static int activate_ep_files (struct dev_data *dev)
1540 {
1541 struct usb_ep *ep;
1542 struct ep_data *data;
1543
1544 gadget_for_each_ep (ep, dev->gadget) {
1545
1546 data = kzalloc(sizeof(*data), GFP_KERNEL);
1547 if (!data)
1548 goto enomem0;
1549 data->state = STATE_EP_DISABLED;
1550 mutex_init(&data->lock);
1551 init_waitqueue_head (&data->wait);
1552
1553 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1554 atomic_set (&data->count, 1);
1555 data->dev = dev;
1556 get_dev (dev);
1557
1558 data->ep = ep;
1559 ep->driver_data = data;
1560
1561 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1562 if (!data->req)
1563 goto enomem1;
1564
1565 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1566 data, &ep_io_operations);
1567 if (!data->dentry)
1568 goto enomem2;
1569 list_add_tail (&data->epfiles, &dev->epfiles);
1570 }
1571 return 0;
1572
1573 enomem2:
1574 usb_ep_free_request (ep, data->req);
1575 enomem1:
1576 put_dev (dev);
1577 kfree (data);
1578 enomem0:
1579 DBG (dev, "%s enomem\n", __func__);
1580 destroy_ep_files (dev);
1581 return -ENOMEM;
1582 }
1583
1584 static void
1585 gadgetfs_unbind (struct usb_gadget *gadget)
1586 {
1587 struct dev_data *dev = get_gadget_data (gadget);
1588
1589 DBG (dev, "%s\n", __func__);
1590
1591 spin_lock_irq (&dev->lock);
1592 dev->state = STATE_DEV_UNBOUND;
1593 spin_unlock_irq (&dev->lock);
1594
1595 destroy_ep_files (dev);
1596 gadget->ep0->driver_data = NULL;
1597 set_gadget_data (gadget, NULL);
1598
1599 /* we've already been disconnected ... no i/o is active */
1600 if (dev->req)
1601 usb_ep_free_request (gadget->ep0, dev->req);
1602 DBG (dev, "%s done\n", __func__);
1603 put_dev (dev);
1604 }
1605
1606 static struct dev_data *the_device;
1607
1608 static int gadgetfs_bind(struct usb_gadget *gadget,
1609 struct usb_gadget_driver *driver)
1610 {
1611 struct dev_data *dev = the_device;
1612
1613 if (!dev)
1614 return -ESRCH;
1615 if (0 != strcmp (CHIP, gadget->name)) {
1616 pr_err("%s expected %s controller not %s\n",
1617 shortname, CHIP, gadget->name);
1618 return -ENODEV;
1619 }
1620
1621 set_gadget_data (gadget, dev);
1622 dev->gadget = gadget;
1623 gadget->ep0->driver_data = dev;
1624
1625 /* preallocate control response and buffer */
1626 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1627 if (!dev->req)
1628 goto enomem;
1629 dev->req->context = NULL;
1630 dev->req->complete = epio_complete;
1631
1632 if (activate_ep_files (dev) < 0)
1633 goto enomem;
1634
1635 INFO (dev, "bound to %s driver\n", gadget->name);
1636 spin_lock_irq(&dev->lock);
1637 dev->state = STATE_DEV_UNCONNECTED;
1638 spin_unlock_irq(&dev->lock);
1639 get_dev (dev);
1640 return 0;
1641
1642 enomem:
1643 gadgetfs_unbind (gadget);
1644 return -ENOMEM;
1645 }
1646
1647 static void
1648 gadgetfs_disconnect (struct usb_gadget *gadget)
1649 {
1650 struct dev_data *dev = get_gadget_data (gadget);
1651 unsigned long flags;
1652
1653 spin_lock_irqsave (&dev->lock, flags);
1654 if (dev->state == STATE_DEV_UNCONNECTED)
1655 goto exit;
1656 dev->state = STATE_DEV_UNCONNECTED;
1657
1658 INFO (dev, "disconnected\n");
1659 next_event (dev, GADGETFS_DISCONNECT);
1660 ep0_readable (dev);
1661 exit:
1662 spin_unlock_irqrestore (&dev->lock, flags);
1663 }
1664
1665 static void
1666 gadgetfs_suspend (struct usb_gadget *gadget)
1667 {
1668 struct dev_data *dev = get_gadget_data (gadget);
1669
1670 INFO (dev, "suspended from state %d\n", dev->state);
1671 spin_lock (&dev->lock);
1672 switch (dev->state) {
1673 case STATE_DEV_SETUP: // VERY odd... host died??
1674 case STATE_DEV_CONNECTED:
1675 case STATE_DEV_UNCONNECTED:
1676 next_event (dev, GADGETFS_SUSPEND);
1677 ep0_readable (dev);
1678 /* FALLTHROUGH */
1679 default:
1680 break;
1681 }
1682 spin_unlock (&dev->lock);
1683 }
1684
1685 static struct usb_gadget_driver gadgetfs_driver = {
1686 .function = (char *) driver_desc,
1687 .bind = gadgetfs_bind,
1688 .unbind = gadgetfs_unbind,
1689 .setup = gadgetfs_setup,
1690 .reset = gadgetfs_disconnect,
1691 .disconnect = gadgetfs_disconnect,
1692 .suspend = gadgetfs_suspend,
1693
1694 .driver = {
1695 .name = (char *) shortname,
1696 },
1697 };
1698
1699 /*----------------------------------------------------------------------*/
1700
1701 static void gadgetfs_nop(struct usb_gadget *arg) { }
1702
1703 static int gadgetfs_probe(struct usb_gadget *gadget,
1704 struct usb_gadget_driver *driver)
1705 {
1706 CHIP = gadget->name;
1707 return -EISNAM;
1708 }
1709
1710 static struct usb_gadget_driver probe_driver = {
1711 .max_speed = USB_SPEED_HIGH,
1712 .bind = gadgetfs_probe,
1713 .unbind = gadgetfs_nop,
1714 .setup = (void *)gadgetfs_nop,
1715 .disconnect = gadgetfs_nop,
1716 .driver = {
1717 .name = "nop",
1718 },
1719 };
1720
1721
1722 /* DEVICE INITIALIZATION
1723 *
1724 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1725 * status = write (fd, descriptors, sizeof descriptors)
1726 *
1727 * That write establishes the device configuration, so the kernel can
1728 * bind to the controller ... guaranteeing it can handle enumeration
1729 * at all necessary speeds. Descriptor order is:
1730 *
1731 * . message tag (u32, host order) ... for now, must be zero; it
1732 * would change to support features like multi-config devices
1733 * . full/low speed config ... all wTotalLength bytes (with interface,
1734 * class, altsetting, endpoint, and other descriptors)
1735 * . high speed config ... all descriptors, for high speed operation;
1736 * this one's optional except for high-speed hardware
1737 * . device descriptor
1738 *
1739 * Endpoints are not yet enabled. Drivers must wait until device
1740 * configuration and interface altsetting changes create
1741 * the need to configure (or unconfigure) them.
1742 *
1743 * After initialization, the device stays active for as long as that
1744 * $CHIP file is open. Events must then be read from that descriptor,
1745 * such as configuration notifications.
1746 */
1747
1748 static int is_valid_config (struct usb_config_descriptor *config)
1749 {
1750 return config->bDescriptorType == USB_DT_CONFIG
1751 && config->bLength == USB_DT_CONFIG_SIZE
1752 && config->bConfigurationValue != 0
1753 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1754 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1755 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1756 /* FIXME check lengths: walk to end */
1757 }
1758
1759 static ssize_t
1760 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1761 {
1762 struct dev_data *dev = fd->private_data;
1763 ssize_t value = len, length = len;
1764 unsigned total;
1765 u32 tag;
1766 char *kbuf;
1767
1768 spin_lock_irq(&dev->lock);
1769 if (dev->state > STATE_DEV_OPENED) {
1770 value = ep0_write(fd, buf, len, ptr);
1771 spin_unlock_irq(&dev->lock);
1772 return value;
1773 }
1774 spin_unlock_irq(&dev->lock);
1775
1776 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1777 return -EINVAL;
1778
1779 /* we might need to change message format someday */
1780 if (copy_from_user (&tag, buf, 4))
1781 return -EFAULT;
1782 if (tag != 0)
1783 return -EINVAL;
1784 buf += 4;
1785 length -= 4;
1786
1787 kbuf = memdup_user(buf, length);
1788 if (IS_ERR(kbuf))
1789 return PTR_ERR(kbuf);
1790
1791 spin_lock_irq (&dev->lock);
1792 value = -EINVAL;
1793 if (dev->buf)
1794 goto fail;
1795 dev->buf = kbuf;
1796
1797 /* full or low speed config */
1798 dev->config = (void *) kbuf;
1799 total = le16_to_cpu(dev->config->wTotalLength);
1800 if (!is_valid_config (dev->config) || total >= length)
1801 goto fail;
1802 kbuf += total;
1803 length -= total;
1804
1805 /* optional high speed config */
1806 if (kbuf [1] == USB_DT_CONFIG) {
1807 dev->hs_config = (void *) kbuf;
1808 total = le16_to_cpu(dev->hs_config->wTotalLength);
1809 if (!is_valid_config (dev->hs_config) || total >= length)
1810 goto fail;
1811 kbuf += total;
1812 length -= total;
1813 }
1814
1815 /* could support multiple configs, using another encoding! */
1816
1817 /* device descriptor (tweaked for paranoia) */
1818 if (length != USB_DT_DEVICE_SIZE)
1819 goto fail;
1820 dev->dev = (void *)kbuf;
1821 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1822 || dev->dev->bDescriptorType != USB_DT_DEVICE
1823 || dev->dev->bNumConfigurations != 1)
1824 goto fail;
1825 dev->dev->bNumConfigurations = 1;
1826 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1827
1828 /* triggers gadgetfs_bind(); then we can enumerate. */
1829 spin_unlock_irq (&dev->lock);
1830 if (dev->hs_config)
1831 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1832 else
1833 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1834
1835 value = usb_gadget_probe_driver(&gadgetfs_driver);
1836 if (value != 0) {
1837 kfree (dev->buf);
1838 dev->buf = NULL;
1839 } else {
1840 /* at this point "good" hardware has for the first time
1841 * let the USB the host see us. alternatively, if users
1842 * unplug/replug that will clear all the error state.
1843 *
1844 * note: everything running before here was guaranteed
1845 * to choke driver model style diagnostics. from here
1846 * on, they can work ... except in cleanup paths that
1847 * kick in after the ep0 descriptor is closed.
1848 */
1849 value = len;
1850 }
1851 return value;
1852
1853 fail:
1854 spin_unlock_irq (&dev->lock);
1855 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1856 kfree (dev->buf);
1857 dev->buf = NULL;
1858 return value;
1859 }
1860
1861 static int
1862 dev_open (struct inode *inode, struct file *fd)
1863 {
1864 struct dev_data *dev = inode->i_private;
1865 int value = -EBUSY;
1866
1867 spin_lock_irq(&dev->lock);
1868 if (dev->state == STATE_DEV_DISABLED) {
1869 dev->ev_next = 0;
1870 dev->state = STATE_DEV_OPENED;
1871 fd->private_data = dev;
1872 get_dev (dev);
1873 value = 0;
1874 }
1875 spin_unlock_irq(&dev->lock);
1876 return value;
1877 }
1878
1879 static const struct file_operations ep0_operations = {
1880 .llseek = no_llseek,
1881
1882 .open = dev_open,
1883 .read = ep0_read,
1884 .write = dev_config,
1885 .fasync = ep0_fasync,
1886 .poll = ep0_poll,
1887 .unlocked_ioctl = dev_ioctl,
1888 .release = dev_release,
1889 };
1890
1891 /*----------------------------------------------------------------------*/
1892
1893 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1894 *
1895 * Mounting the filesystem creates a controller file, used first for
1896 * device configuration then later for event monitoring.
1897 */
1898
1899
1900 /* FIXME PAM etc could set this security policy without mount options
1901 * if epfiles inherited ownership and permissons from ep0 ...
1902 */
1903
1904 static unsigned default_uid;
1905 static unsigned default_gid;
1906 static unsigned default_perm = S_IRUSR | S_IWUSR;
1907
1908 module_param (default_uid, uint, 0644);
1909 module_param (default_gid, uint, 0644);
1910 module_param (default_perm, uint, 0644);
1911
1912
1913 static struct inode *
1914 gadgetfs_make_inode (struct super_block *sb,
1915 void *data, const struct file_operations *fops,
1916 int mode)
1917 {
1918 struct inode *inode = new_inode (sb);
1919
1920 if (inode) {
1921 inode->i_ino = get_next_ino();
1922 inode->i_mode = mode;
1923 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1924 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1925 inode->i_atime = inode->i_mtime = inode->i_ctime
1926 = CURRENT_TIME;
1927 inode->i_private = data;
1928 inode->i_fop = fops;
1929 }
1930 return inode;
1931 }
1932
1933 /* creates in fs root directory, so non-renamable and non-linkable.
1934 * so inode and dentry are paired, until device reconfig.
1935 */
1936 static struct dentry *
1937 gadgetfs_create_file (struct super_block *sb, char const *name,
1938 void *data, const struct file_operations *fops)
1939 {
1940 struct dentry *dentry;
1941 struct inode *inode;
1942
1943 dentry = d_alloc_name(sb->s_root, name);
1944 if (!dentry)
1945 return NULL;
1946
1947 inode = gadgetfs_make_inode (sb, data, fops,
1948 S_IFREG | (default_perm & S_IRWXUGO));
1949 if (!inode) {
1950 dput(dentry);
1951 return NULL;
1952 }
1953 d_add (dentry, inode);
1954 return dentry;
1955 }
1956
1957 static const struct super_operations gadget_fs_operations = {
1958 .statfs = simple_statfs,
1959 .drop_inode = generic_delete_inode,
1960 };
1961
1962 static int
1963 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
1964 {
1965 struct inode *inode;
1966 struct dev_data *dev;
1967
1968 if (the_device)
1969 return -ESRCH;
1970
1971 /* fake probe to determine $CHIP */
1972 CHIP = NULL;
1973 usb_gadget_probe_driver(&probe_driver);
1974 if (!CHIP)
1975 return -ENODEV;
1976
1977 /* superblock */
1978 sb->s_blocksize = PAGE_CACHE_SIZE;
1979 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1980 sb->s_magic = GADGETFS_MAGIC;
1981 sb->s_op = &gadget_fs_operations;
1982 sb->s_time_gran = 1;
1983
1984 /* root inode */
1985 inode = gadgetfs_make_inode (sb,
1986 NULL, &simple_dir_operations,
1987 S_IFDIR | S_IRUGO | S_IXUGO);
1988 if (!inode)
1989 goto Enomem;
1990 inode->i_op = &simple_dir_inode_operations;
1991 if (!(sb->s_root = d_make_root (inode)))
1992 goto Enomem;
1993
1994 /* the ep0 file is named after the controller we expect;
1995 * user mode code can use it for sanity checks, like we do.
1996 */
1997 dev = dev_new ();
1998 if (!dev)
1999 goto Enomem;
2000
2001 dev->sb = sb;
2002 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2003 if (!dev->dentry) {
2004 put_dev(dev);
2005 goto Enomem;
2006 }
2007
2008 /* other endpoint files are available after hardware setup,
2009 * from binding to a controller.
2010 */
2011 the_device = dev;
2012 return 0;
2013
2014 Enomem:
2015 return -ENOMEM;
2016 }
2017
2018 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2019 static struct dentry *
2020 gadgetfs_mount (struct file_system_type *t, int flags,
2021 const char *path, void *opts)
2022 {
2023 return mount_single (t, flags, opts, gadgetfs_fill_super);
2024 }
2025
2026 static void
2027 gadgetfs_kill_sb (struct super_block *sb)
2028 {
2029 kill_litter_super (sb);
2030 if (the_device) {
2031 put_dev (the_device);
2032 the_device = NULL;
2033 }
2034 }
2035
2036 /*----------------------------------------------------------------------*/
2037
2038 static struct file_system_type gadgetfs_type = {
2039 .owner = THIS_MODULE,
2040 .name = shortname,
2041 .mount = gadgetfs_mount,
2042 .kill_sb = gadgetfs_kill_sb,
2043 };
2044 MODULE_ALIAS_FS("gadgetfs");
2045
2046 /*----------------------------------------------------------------------*/
2047
2048 static int __init init (void)
2049 {
2050 int status;
2051
2052 status = register_filesystem (&gadgetfs_type);
2053 if (status == 0)
2054 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2055 shortname, driver_desc);
2056 return status;
2057 }
2058 module_init (init);
2059
2060 static void __exit cleanup (void)
2061 {
2062 pr_debug ("unregister %s\n", shortname);
2063 unregister_filesystem (&gadgetfs_type);
2064 }
2065 module_exit (cleanup);
2066
Linux kernel - Deliverables
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