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