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