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VFS: assorted weird filesystems: d_inode() annotations
[deliverable/linux.git] / drivers / usb / gadget / legacy / inode.c
1 /*
2 * inode.c -- user mode filesystem api for usb gadget controllers
3 *
4 * Copyright (C) 2003-2004 David Brownell
5 * Copyright (C) 2003 Agilent Technologies
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13
14 /* #define VERBOSE_DEBUG */
15
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/fs.h>
19 #include <linux/pagemap.h>
20 #include <linux/uts.h>
21 #include <linux/wait.h>
22 #include <linux/compiler.h>
23 #include <asm/uaccess.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/poll.h>
27 #include <linux/mmu_context.h>
28 #include <linux/aio.h>
29 #include <linux/uio.h>
30
31 #include <linux/device.h>
32 #include <linux/moduleparam.h>
33
34 #include <linux/usb/gadgetfs.h>
35 #include <linux/usb/gadget.h>
36
37
38 /*
39 * The gadgetfs API maps each endpoint to a file descriptor so that you
40 * can use standard synchronous read/write calls for I/O. There's some
41 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
42 * drivers show how this works in practice. You can also use AIO to
43 * eliminate I/O gaps between requests, to help when streaming data.
44 *
45 * Key parts that must be USB-specific are protocols defining how the
46 * read/write operations relate to the hardware state machines. There
47 * are two types of files. One type is for the device, implementing ep0.
48 * The other type is for each IN or OUT endpoint. In both cases, the
49 * user mode driver must configure the hardware before using it.
50 *
51 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
52 * (by writing configuration and device descriptors). Afterwards it
53 * may serve as a source of device events, used to handle all control
54 * requests other than basic enumeration.
55 *
56 * - Then, after a SET_CONFIGURATION control request, ep_config() is
57 * called when each /dev/gadget/ep* file is configured (by writing
58 * endpoint descriptors). Afterwards these files are used to write()
59 * IN data or to read() OUT data. To halt the endpoint, a "wrong
60 * direction" request is issued (like reading an IN endpoint).
61 *
62 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
63 * not possible on all hardware. For example, precise fault handling with
64 * respect to data left in endpoint fifos after aborted operations; or
65 * selective clearing of endpoint halts, to implement SET_INTERFACE.
66 */
67
68 #define DRIVER_DESC "USB Gadget filesystem"
69 #define DRIVER_VERSION "24 Aug 2004"
70
71 static const char driver_desc [] = DRIVER_DESC;
72 static const char shortname [] = "gadgetfs";
73
74 MODULE_DESCRIPTION (DRIVER_DESC);
75 MODULE_AUTHOR ("David Brownell");
76 MODULE_LICENSE ("GPL");
77
78 static int ep_open(struct inode *, struct file *);
79
80
81 /*----------------------------------------------------------------------*/
82
83 #define GADGETFS_MAGIC 0xaee71ee7
84
85 /* /dev/gadget/$CHIP represents ep0 and the whole device */
86 enum ep0_state {
87 /* DISBLED is the initial state.
88 */
89 STATE_DEV_DISABLED = 0,
90
91 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
92 * ep0/device i/o modes and binding to the controller. Driver
93 * must always write descriptors to initialize the device, then
94 * the device becomes UNCONNECTED until enumeration.
95 */
96 STATE_DEV_OPENED,
97
98 /* From then on, ep0 fd is in either of two basic modes:
99 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
100 * - SETUP: read/write will transfer control data and succeed;
101 * or if "wrong direction", performs protocol stall
102 */
103 STATE_DEV_UNCONNECTED,
104 STATE_DEV_CONNECTED,
105 STATE_DEV_SETUP,
106
107 /* UNBOUND means the driver closed ep0, so the device won't be
108 * accessible again (DEV_DISABLED) until all fds are closed.
109 */
110 STATE_DEV_UNBOUND,
111 };
112
113 /* enough for the whole queue: most events invalidate others */
114 #define N_EVENT 5
115
116 struct dev_data {
117 spinlock_t lock;
118 atomic_t count;
119 enum ep0_state state; /* P: lock */
120 struct usb_gadgetfs_event event [N_EVENT];
121 unsigned ev_next;
122 struct fasync_struct *fasync;
123 u8 current_config;
124
125 /* drivers reading ep0 MUST handle control requests (SETUP)
126 * reported that way; else the host will time out.
127 */
128 unsigned usermode_setup : 1,
129 setup_in : 1,
130 setup_can_stall : 1,
131 setup_out_ready : 1,
132 setup_out_error : 1,
133 setup_abort : 1;
134 unsigned setup_wLength;
135
136 /* the rest is basically write-once */
137 struct usb_config_descriptor *config, *hs_config;
138 struct usb_device_descriptor *dev;
139 struct usb_request *req;
140 struct usb_gadget *gadget;
141 struct list_head epfiles;
142 void *buf;
143 wait_queue_head_t wait;
144 struct super_block *sb;
145 struct dentry *dentry;
146
147 /* except this scratch i/o buffer for ep0 */
148 u8 rbuf [256];
149 };
150
151 static inline void get_dev (struct dev_data *data)
152 {
153 atomic_inc (&data->count);
154 }
155
156 static void put_dev (struct dev_data *data)
157 {
158 if (likely (!atomic_dec_and_test (&data->count)))
159 return;
160 /* needs no more cleanup */
161 BUG_ON (waitqueue_active (&data->wait));
162 kfree (data);
163 }
164
165 static struct dev_data *dev_new (void)
166 {
167 struct dev_data *dev;
168
169 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
170 if (!dev)
171 return NULL;
172 dev->state = STATE_DEV_DISABLED;
173 atomic_set (&dev->count, 1);
174 spin_lock_init (&dev->lock);
175 INIT_LIST_HEAD (&dev->epfiles);
176 init_waitqueue_head (&dev->wait);
177 return dev;
178 }
179
180 /*----------------------------------------------------------------------*/
181
182 /* other /dev/gadget/$ENDPOINT files represent endpoints */
183 enum ep_state {
184 STATE_EP_DISABLED = 0,
185 STATE_EP_READY,
186 STATE_EP_ENABLED,
187 STATE_EP_UNBOUND,
188 };
189
190 struct ep_data {
191 struct mutex lock;
192 enum ep_state state;
193 atomic_t count;
194 struct dev_data *dev;
195 /* must hold dev->lock before accessing ep or req */
196 struct usb_ep *ep;
197 struct usb_request *req;
198 ssize_t status;
199 char name [16];
200 struct usb_endpoint_descriptor desc, hs_desc;
201 struct list_head epfiles;
202 wait_queue_head_t wait;
203 struct dentry *dentry;
204 };
205
206 static inline void get_ep (struct ep_data *data)
207 {
208 atomic_inc (&data->count);
209 }
210
211 static void put_ep (struct ep_data *data)
212 {
213 if (likely (!atomic_dec_and_test (&data->count)))
214 return;
215 put_dev (data->dev);
216 /* needs no more cleanup */
217 BUG_ON (!list_empty (&data->epfiles));
218 BUG_ON (waitqueue_active (&data->wait));
219 kfree (data);
220 }
221
222 /*----------------------------------------------------------------------*/
223
224 /* most "how to use the hardware" policy choices are in userspace:
225 * mapping endpoint roles (which the driver needs) to the capabilities
226 * which the usb controller has. most of those capabilities are exposed
227 * implicitly, starting with the driver name and then endpoint names.
228 */
229
230 static const char *CHIP;
231
232 /*----------------------------------------------------------------------*/
233
234 /* NOTE: don't use dev_printk calls before binding to the gadget
235 * at the end of ep0 configuration, or after unbind.
236 */
237
238 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
239 #define xprintk(d,level,fmt,args...) \
240 printk(level "%s: " fmt , shortname , ## args)
241
242 #ifdef DEBUG
243 #define DBG(dev,fmt,args...) \
244 xprintk(dev , KERN_DEBUG , fmt , ## args)
245 #else
246 #define DBG(dev,fmt,args...) \
247 do { } while (0)
248 #endif /* DEBUG */
249
250 #ifdef VERBOSE_DEBUG
251 #define VDEBUG DBG
252 #else
253 #define VDEBUG(dev,fmt,args...) \
254 do { } while (0)
255 #endif /* DEBUG */
256
257 #define ERROR(dev,fmt,args...) \
258 xprintk(dev , KERN_ERR , fmt , ## args)
259 #define INFO(dev,fmt,args...) \
260 xprintk(dev , KERN_INFO , fmt , ## args)
261
262
263 /*----------------------------------------------------------------------*/
264
265 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
266 *
267 * After opening, configure non-control endpoints. Then use normal
268 * stream read() and write() requests; and maybe ioctl() to get more
269 * precise FIFO status when recovering from cancellation.
270 */
271
272 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
273 {
274 struct ep_data *epdata = ep->driver_data;
275
276 if (!req->context)
277 return;
278 if (req->status)
279 epdata->status = req->status;
280 else
281 epdata->status = req->actual;
282 complete ((struct completion *)req->context);
283 }
284
285 /* tasklock endpoint, returning when it's connected.
286 * still need dev->lock to use epdata->ep.
287 */
288 static int
289 get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
290 {
291 int val;
292
293 if (f_flags & O_NONBLOCK) {
294 if (!mutex_trylock(&epdata->lock))
295 goto nonblock;
296 if (epdata->state != STATE_EP_ENABLED &&
297 (!is_write || epdata->state != STATE_EP_READY)) {
298 mutex_unlock(&epdata->lock);
299 nonblock:
300 val = -EAGAIN;
301 } else
302 val = 0;
303 return val;
304 }
305
306 val = mutex_lock_interruptible(&epdata->lock);
307 if (val < 0)
308 return val;
309
310 switch (epdata->state) {
311 case STATE_EP_ENABLED:
312 return 0;
313 case STATE_EP_READY: /* not configured yet */
314 if (is_write)
315 return 0;
316 // FALLTHRU
317 case STATE_EP_UNBOUND: /* clean disconnect */
318 break;
319 // case STATE_EP_DISABLED: /* "can't happen" */
320 default: /* error! */
321 pr_debug ("%s: ep %p not available, state %d\n",
322 shortname, epdata, epdata->state);
323 }
324 mutex_unlock(&epdata->lock);
325 return -ENODEV;
326 }
327
328 static ssize_t
329 ep_io (struct ep_data *epdata, void *buf, unsigned len)
330 {
331 DECLARE_COMPLETION_ONSTACK (done);
332 int value;
333
334 spin_lock_irq (&epdata->dev->lock);
335 if (likely (epdata->ep != NULL)) {
336 struct usb_request *req = epdata->req;
337
338 req->context = &done;
339 req->complete = epio_complete;
340 req->buf = buf;
341 req->length = len;
342 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
343 } else
344 value = -ENODEV;
345 spin_unlock_irq (&epdata->dev->lock);
346
347 if (likely (value == 0)) {
348 value = wait_event_interruptible (done.wait, done.done);
349 if (value != 0) {
350 spin_lock_irq (&epdata->dev->lock);
351 if (likely (epdata->ep != NULL)) {
352 DBG (epdata->dev, "%s i/o interrupted\n",
353 epdata->name);
354 usb_ep_dequeue (epdata->ep, epdata->req);
355 spin_unlock_irq (&epdata->dev->lock);
356
357 wait_event (done.wait, done.done);
358 if (epdata->status == -ECONNRESET)
359 epdata->status = -EINTR;
360 } else {
361 spin_unlock_irq (&epdata->dev->lock);
362
363 DBG (epdata->dev, "endpoint gone\n");
364 epdata->status = -ENODEV;
365 }
366 }
367 return epdata->status;
368 }
369 return value;
370 }
371
372 static int
373 ep_release (struct inode *inode, struct file *fd)
374 {
375 struct ep_data *data = fd->private_data;
376 int value;
377
378 value = mutex_lock_interruptible(&data->lock);
379 if (value < 0)
380 return value;
381
382 /* clean up if this can be reopened */
383 if (data->state != STATE_EP_UNBOUND) {
384 data->state = STATE_EP_DISABLED;
385 data->desc.bDescriptorType = 0;
386 data->hs_desc.bDescriptorType = 0;
387 usb_ep_disable(data->ep);
388 }
389 mutex_unlock(&data->lock);
390 put_ep (data);
391 return 0;
392 }
393
394 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
395 {
396 struct ep_data *data = fd->private_data;
397 int status;
398
399 if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
400 return status;
401
402 spin_lock_irq (&data->dev->lock);
403 if (likely (data->ep != NULL)) {
404 switch (code) {
405 case GADGETFS_FIFO_STATUS:
406 status = usb_ep_fifo_status (data->ep);
407 break;
408 case GADGETFS_FIFO_FLUSH:
409 usb_ep_fifo_flush (data->ep);
410 break;
411 case GADGETFS_CLEAR_HALT:
412 status = usb_ep_clear_halt (data->ep);
413 break;
414 default:
415 status = -ENOTTY;
416 }
417 } else
418 status = -ENODEV;
419 spin_unlock_irq (&data->dev->lock);
420 mutex_unlock(&data->lock);
421 return status;
422 }
423
424 /*----------------------------------------------------------------------*/
425
426 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
427
428 struct kiocb_priv {
429 struct usb_request *req;
430 struct ep_data *epdata;
431 struct kiocb *iocb;
432 struct mm_struct *mm;
433 struct work_struct work;
434 void *buf;
435 struct iov_iter to;
436 const void *to_free;
437 unsigned actual;
438 };
439
440 static int ep_aio_cancel(struct kiocb *iocb)
441 {
442 struct kiocb_priv *priv = iocb->private;
443 struct ep_data *epdata;
444 int value;
445
446 local_irq_disable();
447 epdata = priv->epdata;
448 // spin_lock(&epdata->dev->lock);
449 if (likely(epdata && epdata->ep && priv->req))
450 value = usb_ep_dequeue (epdata->ep, priv->req);
451 else
452 value = -EINVAL;
453 // spin_unlock(&epdata->dev->lock);
454 local_irq_enable();
455
456 return value;
457 }
458
459 static void ep_user_copy_worker(struct work_struct *work)
460 {
461 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
462 struct mm_struct *mm = priv->mm;
463 struct kiocb *iocb = priv->iocb;
464 size_t ret;
465
466 use_mm(mm);
467 ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
468 unuse_mm(mm);
469 if (!ret)
470 ret = -EFAULT;
471
472 /* completing the iocb can drop the ctx and mm, don't touch mm after */
473 iocb->ki_complete(iocb, ret, ret);
474
475 kfree(priv->buf);
476 kfree(priv->to_free);
477 kfree(priv);
478 }
479
480 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
481 {
482 struct kiocb *iocb = req->context;
483 struct kiocb_priv *priv = iocb->private;
484 struct ep_data *epdata = priv->epdata;
485
486 /* lock against disconnect (and ideally, cancel) */
487 spin_lock(&epdata->dev->lock);
488 priv->req = NULL;
489 priv->epdata = NULL;
490
491 /* if this was a write or a read returning no data then we
492 * don't need to copy anything to userspace, so we can
493 * complete the aio request immediately.
494 */
495 if (priv->to_free == NULL || unlikely(req->actual == 0)) {
496 kfree(req->buf);
497 kfree(priv->to_free);
498 kfree(priv);
499 iocb->private = NULL;
500 /* aio_complete() reports bytes-transferred _and_ faults */
501
502 iocb->ki_complete(iocb, req->actual ? req->actual : req->status,
503 req->status);
504 } else {
505 /* ep_copy_to_user() won't report both; we hide some faults */
506 if (unlikely(0 != req->status))
507 DBG(epdata->dev, "%s fault %d len %d\n",
508 ep->name, req->status, req->actual);
509
510 priv->buf = req->buf;
511 priv->actual = req->actual;
512 INIT_WORK(&priv->work, ep_user_copy_worker);
513 schedule_work(&priv->work);
514 }
515 spin_unlock(&epdata->dev->lock);
516
517 usb_ep_free_request(ep, req);
518 put_ep(epdata);
519 }
520
521 static ssize_t ep_aio(struct kiocb *iocb,
522 struct kiocb_priv *priv,
523 struct ep_data *epdata,
524 char *buf,
525 size_t len)
526 {
527 struct usb_request *req;
528 ssize_t value;
529
530 iocb->private = priv;
531 priv->iocb = iocb;
532
533 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
534 get_ep(epdata);
535 priv->epdata = epdata;
536 priv->actual = 0;
537 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
538
539 /* each kiocb is coupled to one usb_request, but we can't
540 * allocate or submit those if the host disconnected.
541 */
542 spin_lock_irq(&epdata->dev->lock);
543 value = -ENODEV;
544 if (unlikely(epdata->ep))
545 goto fail;
546
547 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
548 value = -ENOMEM;
549 if (unlikely(!req))
550 goto fail;
551
552 priv->req = req;
553 req->buf = buf;
554 req->length = len;
555 req->complete = ep_aio_complete;
556 req->context = iocb;
557 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
558 if (unlikely(0 != value)) {
559 usb_ep_free_request(epdata->ep, req);
560 goto fail;
561 }
562 spin_unlock_irq(&epdata->dev->lock);
563 return -EIOCBQUEUED;
564
565 fail:
566 spin_unlock_irq(&epdata->dev->lock);
567 kfree(priv->to_free);
568 kfree(priv);
569 put_ep(epdata);
570 return value;
571 }
572
573 static ssize_t
574 ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
575 {
576 struct file *file = iocb->ki_filp;
577 struct ep_data *epdata = file->private_data;
578 size_t len = iov_iter_count(to);
579 ssize_t value;
580 char *buf;
581
582 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
583 return value;
584
585 /* halt any endpoint by doing a "wrong direction" i/o call */
586 if (usb_endpoint_dir_in(&epdata->desc)) {
587 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
588 !is_sync_kiocb(iocb)) {
589 mutex_unlock(&epdata->lock);
590 return -EINVAL;
591 }
592 DBG (epdata->dev, "%s halt\n", epdata->name);
593 spin_lock_irq(&epdata->dev->lock);
594 if (likely(epdata->ep != NULL))
595 usb_ep_set_halt(epdata->ep);
596 spin_unlock_irq(&epdata->dev->lock);
597 mutex_unlock(&epdata->lock);
598 return -EBADMSG;
599 }
600
601 buf = kmalloc(len, GFP_KERNEL);
602 if (unlikely(!buf)) {
603 mutex_unlock(&epdata->lock);
604 return -ENOMEM;
605 }
606 if (is_sync_kiocb(iocb)) {
607 value = ep_io(epdata, buf, len);
608 if (value >= 0 && copy_to_iter(buf, value, to))
609 value = -EFAULT;
610 } else {
611 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
612 value = -ENOMEM;
613 if (!priv)
614 goto fail;
615 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
616 if (!priv->to_free) {
617 kfree(priv);
618 goto fail;
619 }
620 value = ep_aio(iocb, priv, epdata, buf, len);
621 if (value == -EIOCBQUEUED)
622 buf = NULL;
623 }
624 fail:
625 kfree(buf);
626 mutex_unlock(&epdata->lock);
627 return value;
628 }
629
630 static ssize_t ep_config(struct ep_data *, const char *, size_t);
631
632 static ssize_t
633 ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
634 {
635 struct file *file = iocb->ki_filp;
636 struct ep_data *epdata = file->private_data;
637 size_t len = iov_iter_count(from);
638 bool configured;
639 ssize_t value;
640 char *buf;
641
642 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
643 return value;
644
645 configured = epdata->state == STATE_EP_ENABLED;
646
647 /* halt any endpoint by doing a "wrong direction" i/o call */
648 if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
649 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
650 !is_sync_kiocb(iocb)) {
651 mutex_unlock(&epdata->lock);
652 return -EINVAL;
653 }
654 DBG (epdata->dev, "%s halt\n", epdata->name);
655 spin_lock_irq(&epdata->dev->lock);
656 if (likely(epdata->ep != NULL))
657 usb_ep_set_halt(epdata->ep);
658 spin_unlock_irq(&epdata->dev->lock);
659 mutex_unlock(&epdata->lock);
660 return -EBADMSG;
661 }
662
663 buf = kmalloc(len, GFP_KERNEL);
664 if (unlikely(!buf)) {
665 mutex_unlock(&epdata->lock);
666 return -ENOMEM;
667 }
668
669 if (unlikely(copy_from_iter(buf, len, from) != len)) {
670 value = -EFAULT;
671 goto out;
672 }
673
674 if (unlikely(!configured)) {
675 value = ep_config(epdata, buf, len);
676 } else if (is_sync_kiocb(iocb)) {
677 value = ep_io(epdata, buf, len);
678 } else {
679 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
680 value = -ENOMEM;
681 if (priv) {
682 value = ep_aio(iocb, priv, epdata, buf, len);
683 if (value == -EIOCBQUEUED)
684 buf = NULL;
685 }
686 }
687 out:
688 kfree(buf);
689 mutex_unlock(&epdata->lock);
690 return value;
691 }
692
693 /*----------------------------------------------------------------------*/
694
695 /* used after endpoint configuration */
696 static const struct file_operations ep_io_operations = {
697 .owner = THIS_MODULE,
698
699 .open = ep_open,
700 .release = ep_release,
701 .llseek = no_llseek,
702 .unlocked_ioctl = ep_ioctl,
703 .read_iter = ep_read_iter,
704 .write_iter = ep_write_iter,
705 };
706
707 /* ENDPOINT INITIALIZATION
708 *
709 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
710 * status = write (fd, descriptors, sizeof descriptors)
711 *
712 * That write establishes the endpoint configuration, configuring
713 * the controller to process bulk, interrupt, or isochronous transfers
714 * at the right maxpacket size, and so on.
715 *
716 * The descriptors are message type 1, identified by a host order u32
717 * at the beginning of what's written. Descriptor order is: full/low
718 * speed descriptor, then optional high speed descriptor.
719 */
720 static ssize_t
721 ep_config (struct ep_data *data, const char *buf, size_t len)
722 {
723 struct usb_ep *ep;
724 u32 tag;
725 int value, length = len;
726
727 if (data->state != STATE_EP_READY) {
728 value = -EL2HLT;
729 goto fail;
730 }
731
732 value = len;
733 if (len < USB_DT_ENDPOINT_SIZE + 4)
734 goto fail0;
735
736 /* we might need to change message format someday */
737 memcpy(&tag, buf, 4);
738 if (tag != 1) {
739 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
740 goto fail0;
741 }
742 buf += 4;
743 len -= 4;
744
745 /* NOTE: audio endpoint extensions not accepted here;
746 * just don't include the extra bytes.
747 */
748
749 /* full/low speed descriptor, then high speed */
750 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
751 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
752 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
753 goto fail0;
754 if (len != USB_DT_ENDPOINT_SIZE) {
755 if (len != 2 * USB_DT_ENDPOINT_SIZE)
756 goto fail0;
757 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
758 USB_DT_ENDPOINT_SIZE);
759 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
760 || data->hs_desc.bDescriptorType
761 != USB_DT_ENDPOINT) {
762 DBG(data->dev, "config %s, bad hs length or type\n",
763 data->name);
764 goto fail0;
765 }
766 }
767
768 spin_lock_irq (&data->dev->lock);
769 if (data->dev->state == STATE_DEV_UNBOUND) {
770 value = -ENOENT;
771 goto gone;
772 } else if ((ep = data->ep) == NULL) {
773 value = -ENODEV;
774 goto gone;
775 }
776 switch (data->dev->gadget->speed) {
777 case USB_SPEED_LOW:
778 case USB_SPEED_FULL:
779 ep->desc = &data->desc;
780 break;
781 case USB_SPEED_HIGH:
782 /* fails if caller didn't provide that descriptor... */
783 ep->desc = &data->hs_desc;
784 break;
785 default:
786 DBG(data->dev, "unconnected, %s init abandoned\n",
787 data->name);
788 value = -EINVAL;
789 goto gone;
790 }
791 value = usb_ep_enable(ep);
792 if (value == 0) {
793 data->state = STATE_EP_ENABLED;
794 value = length;
795 }
796 gone:
797 spin_unlock_irq (&data->dev->lock);
798 if (value < 0) {
799 fail:
800 data->desc.bDescriptorType = 0;
801 data->hs_desc.bDescriptorType = 0;
802 }
803 return value;
804 fail0:
805 value = -EINVAL;
806 goto fail;
807 }
808
809 static int
810 ep_open (struct inode *inode, struct file *fd)
811 {
812 struct ep_data *data = inode->i_private;
813 int value = -EBUSY;
814
815 if (mutex_lock_interruptible(&data->lock) != 0)
816 return -EINTR;
817 spin_lock_irq (&data->dev->lock);
818 if (data->dev->state == STATE_DEV_UNBOUND)
819 value = -ENOENT;
820 else if (data->state == STATE_EP_DISABLED) {
821 value = 0;
822 data->state = STATE_EP_READY;
823 get_ep (data);
824 fd->private_data = data;
825 VDEBUG (data->dev, "%s ready\n", data->name);
826 } else
827 DBG (data->dev, "%s state %d\n",
828 data->name, data->state);
829 spin_unlock_irq (&data->dev->lock);
830 mutex_unlock(&data->lock);
831 return value;
832 }
833
834 /*----------------------------------------------------------------------*/
835
836 /* EP0 IMPLEMENTATION can be partly in userspace.
837 *
838 * Drivers that use this facility receive various events, including
839 * control requests the kernel doesn't handle. Drivers that don't
840 * use this facility may be too simple-minded for real applications.
841 */
842
843 static inline void ep0_readable (struct dev_data *dev)
844 {
845 wake_up (&dev->wait);
846 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
847 }
848
849 static void clean_req (struct usb_ep *ep, struct usb_request *req)
850 {
851 struct dev_data *dev = ep->driver_data;
852
853 if (req->buf != dev->rbuf) {
854 kfree(req->buf);
855 req->buf = dev->rbuf;
856 }
857 req->complete = epio_complete;
858 dev->setup_out_ready = 0;
859 }
860
861 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
862 {
863 struct dev_data *dev = ep->driver_data;
864 unsigned long flags;
865 int free = 1;
866
867 /* for control OUT, data must still get to userspace */
868 spin_lock_irqsave(&dev->lock, flags);
869 if (!dev->setup_in) {
870 dev->setup_out_error = (req->status != 0);
871 if (!dev->setup_out_error)
872 free = 0;
873 dev->setup_out_ready = 1;
874 ep0_readable (dev);
875 }
876
877 /* clean up as appropriate */
878 if (free && req->buf != &dev->rbuf)
879 clean_req (ep, req);
880 req->complete = epio_complete;
881 spin_unlock_irqrestore(&dev->lock, flags);
882 }
883
884 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
885 {
886 struct dev_data *dev = ep->driver_data;
887
888 if (dev->setup_out_ready) {
889 DBG (dev, "ep0 request busy!\n");
890 return -EBUSY;
891 }
892 if (len > sizeof (dev->rbuf))
893 req->buf = kmalloc(len, GFP_ATOMIC);
894 if (req->buf == NULL) {
895 req->buf = dev->rbuf;
896 return -ENOMEM;
897 }
898 req->complete = ep0_complete;
899 req->length = len;
900 req->zero = 0;
901 return 0;
902 }
903
904 static ssize_t
905 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
906 {
907 struct dev_data *dev = fd->private_data;
908 ssize_t retval;
909 enum ep0_state state;
910
911 spin_lock_irq (&dev->lock);
912 if (dev->state <= STATE_DEV_OPENED) {
913 retval = -EINVAL;
914 goto done;
915 }
916
917 /* report fd mode change before acting on it */
918 if (dev->setup_abort) {
919 dev->setup_abort = 0;
920 retval = -EIDRM;
921 goto done;
922 }
923
924 /* control DATA stage */
925 if ((state = dev->state) == STATE_DEV_SETUP) {
926
927 if (dev->setup_in) { /* stall IN */
928 VDEBUG(dev, "ep0in stall\n");
929 (void) usb_ep_set_halt (dev->gadget->ep0);
930 retval = -EL2HLT;
931 dev->state = STATE_DEV_CONNECTED;
932
933 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
934 struct usb_ep *ep = dev->gadget->ep0;
935 struct usb_request *req = dev->req;
936
937 if ((retval = setup_req (ep, req, 0)) == 0)
938 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
939 dev->state = STATE_DEV_CONNECTED;
940
941 /* assume that was SET_CONFIGURATION */
942 if (dev->current_config) {
943 unsigned power;
944
945 if (gadget_is_dualspeed(dev->gadget)
946 && (dev->gadget->speed
947 == USB_SPEED_HIGH))
948 power = dev->hs_config->bMaxPower;
949 else
950 power = dev->config->bMaxPower;
951 usb_gadget_vbus_draw(dev->gadget, 2 * power);
952 }
953
954 } else { /* collect OUT data */
955 if ((fd->f_flags & O_NONBLOCK) != 0
956 && !dev->setup_out_ready) {
957 retval = -EAGAIN;
958 goto done;
959 }
960 spin_unlock_irq (&dev->lock);
961 retval = wait_event_interruptible (dev->wait,
962 dev->setup_out_ready != 0);
963
964 /* FIXME state could change from under us */
965 spin_lock_irq (&dev->lock);
966 if (retval)
967 goto done;
968
969 if (dev->state != STATE_DEV_SETUP) {
970 retval = -ECANCELED;
971 goto done;
972 }
973 dev->state = STATE_DEV_CONNECTED;
974
975 if (dev->setup_out_error)
976 retval = -EIO;
977 else {
978 len = min (len, (size_t)dev->req->actual);
979 // FIXME don't call this with the spinlock held ...
980 if (copy_to_user (buf, dev->req->buf, len))
981 retval = -EFAULT;
982 else
983 retval = len;
984 clean_req (dev->gadget->ep0, dev->req);
985 /* NOTE userspace can't yet choose to stall */
986 }
987 }
988 goto done;
989 }
990
991 /* else normal: return event data */
992 if (len < sizeof dev->event [0]) {
993 retval = -EINVAL;
994 goto done;
995 }
996 len -= len % sizeof (struct usb_gadgetfs_event);
997 dev->usermode_setup = 1;
998
999 scan:
1000 /* return queued events right away */
1001 if (dev->ev_next != 0) {
1002 unsigned i, n;
1003
1004 n = len / sizeof (struct usb_gadgetfs_event);
1005 if (dev->ev_next < n)
1006 n = dev->ev_next;
1007
1008 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1009 for (i = 0; i < n; i++) {
1010 if (dev->event [i].type == GADGETFS_SETUP) {
1011 dev->state = STATE_DEV_SETUP;
1012 n = i + 1;
1013 break;
1014 }
1015 }
1016 spin_unlock_irq (&dev->lock);
1017 len = n * sizeof (struct usb_gadgetfs_event);
1018 if (copy_to_user (buf, &dev->event, len))
1019 retval = -EFAULT;
1020 else
1021 retval = len;
1022 if (len > 0) {
1023 /* NOTE this doesn't guard against broken drivers;
1024 * concurrent ep0 readers may lose events.
1025 */
1026 spin_lock_irq (&dev->lock);
1027 if (dev->ev_next > n) {
1028 memmove(&dev->event[0], &dev->event[n],
1029 sizeof (struct usb_gadgetfs_event)
1030 * (dev->ev_next - n));
1031 }
1032 dev->ev_next -= n;
1033 spin_unlock_irq (&dev->lock);
1034 }
1035 return retval;
1036 }
1037 if (fd->f_flags & O_NONBLOCK) {
1038 retval = -EAGAIN;
1039 goto done;
1040 }
1041
1042 switch (state) {
1043 default:
1044 DBG (dev, "fail %s, state %d\n", __func__, state);
1045 retval = -ESRCH;
1046 break;
1047 case STATE_DEV_UNCONNECTED:
1048 case STATE_DEV_CONNECTED:
1049 spin_unlock_irq (&dev->lock);
1050 DBG (dev, "%s wait\n", __func__);
1051
1052 /* wait for events */
1053 retval = wait_event_interruptible (dev->wait,
1054 dev->ev_next != 0);
1055 if (retval < 0)
1056 return retval;
1057 spin_lock_irq (&dev->lock);
1058 goto scan;
1059 }
1060
1061 done:
1062 spin_unlock_irq (&dev->lock);
1063 return retval;
1064 }
1065
1066 static struct usb_gadgetfs_event *
1067 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1068 {
1069 struct usb_gadgetfs_event *event;
1070 unsigned i;
1071
1072 switch (type) {
1073 /* these events purge the queue */
1074 case GADGETFS_DISCONNECT:
1075 if (dev->state == STATE_DEV_SETUP)
1076 dev->setup_abort = 1;
1077 // FALL THROUGH
1078 case GADGETFS_CONNECT:
1079 dev->ev_next = 0;
1080 break;
1081 case GADGETFS_SETUP: /* previous request timed out */
1082 case GADGETFS_SUSPEND: /* same effect */
1083 /* these events can't be repeated */
1084 for (i = 0; i != dev->ev_next; i++) {
1085 if (dev->event [i].type != type)
1086 continue;
1087 DBG(dev, "discard old event[%d] %d\n", i, type);
1088 dev->ev_next--;
1089 if (i == dev->ev_next)
1090 break;
1091 /* indices start at zero, for simplicity */
1092 memmove (&dev->event [i], &dev->event [i + 1],
1093 sizeof (struct usb_gadgetfs_event)
1094 * (dev->ev_next - i));
1095 }
1096 break;
1097 default:
1098 BUG ();
1099 }
1100 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1101 event = &dev->event [dev->ev_next++];
1102 BUG_ON (dev->ev_next > N_EVENT);
1103 memset (event, 0, sizeof *event);
1104 event->type = type;
1105 return event;
1106 }
1107
1108 static ssize_t
1109 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1110 {
1111 struct dev_data *dev = fd->private_data;
1112 ssize_t retval = -ESRCH;
1113
1114 /* report fd mode change before acting on it */
1115 if (dev->setup_abort) {
1116 dev->setup_abort = 0;
1117 retval = -EIDRM;
1118
1119 /* data and/or status stage for control request */
1120 } else if (dev->state == STATE_DEV_SETUP) {
1121
1122 /* IN DATA+STATUS caller makes len <= wLength */
1123 if (dev->setup_in) {
1124 retval = setup_req (dev->gadget->ep0, dev->req, len);
1125 if (retval == 0) {
1126 dev->state = STATE_DEV_CONNECTED;
1127 spin_unlock_irq (&dev->lock);
1128 if (copy_from_user (dev->req->buf, buf, len))
1129 retval = -EFAULT;
1130 else {
1131 if (len < dev->setup_wLength)
1132 dev->req->zero = 1;
1133 retval = usb_ep_queue (
1134 dev->gadget->ep0, dev->req,
1135 GFP_KERNEL);
1136 }
1137 if (retval < 0) {
1138 spin_lock_irq (&dev->lock);
1139 clean_req (dev->gadget->ep0, dev->req);
1140 spin_unlock_irq (&dev->lock);
1141 } else
1142 retval = len;
1143
1144 return retval;
1145 }
1146
1147 /* can stall some OUT transfers */
1148 } else if (dev->setup_can_stall) {
1149 VDEBUG(dev, "ep0out stall\n");
1150 (void) usb_ep_set_halt (dev->gadget->ep0);
1151 retval = -EL2HLT;
1152 dev->state = STATE_DEV_CONNECTED;
1153 } else {
1154 DBG(dev, "bogus ep0out stall!\n");
1155 }
1156 } else
1157 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1158
1159 return retval;
1160 }
1161
1162 static int
1163 ep0_fasync (int f, struct file *fd, int on)
1164 {
1165 struct dev_data *dev = fd->private_data;
1166 // caller must F_SETOWN before signal delivery happens
1167 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1168 return fasync_helper (f, fd, on, &dev->fasync);
1169 }
1170
1171 static struct usb_gadget_driver gadgetfs_driver;
1172
1173 static int
1174 dev_release (struct inode *inode, struct file *fd)
1175 {
1176 struct dev_data *dev = fd->private_data;
1177
1178 /* closing ep0 === shutdown all */
1179
1180 usb_gadget_unregister_driver (&gadgetfs_driver);
1181
1182 /* at this point "good" hardware has disconnected the
1183 * device from USB; the host won't see it any more.
1184 * alternatively, all host requests will time out.
1185 */
1186
1187 kfree (dev->buf);
1188 dev->buf = NULL;
1189
1190 /* other endpoints were all decoupled from this device */
1191 spin_lock_irq(&dev->lock);
1192 dev->state = STATE_DEV_DISABLED;
1193 spin_unlock_irq(&dev->lock);
1194
1195 put_dev (dev);
1196 return 0;
1197 }
1198
1199 static unsigned int
1200 ep0_poll (struct file *fd, poll_table *wait)
1201 {
1202 struct dev_data *dev = fd->private_data;
1203 int mask = 0;
1204
1205 if (dev->state <= STATE_DEV_OPENED)
1206 return DEFAULT_POLLMASK;
1207
1208 poll_wait(fd, &dev->wait, wait);
1209
1210 spin_lock_irq (&dev->lock);
1211
1212 /* report fd mode change before acting on it */
1213 if (dev->setup_abort) {
1214 dev->setup_abort = 0;
1215 mask = POLLHUP;
1216 goto out;
1217 }
1218
1219 if (dev->state == STATE_DEV_SETUP) {
1220 if (dev->setup_in || dev->setup_can_stall)
1221 mask = POLLOUT;
1222 } else {
1223 if (dev->ev_next != 0)
1224 mask = POLLIN;
1225 }
1226 out:
1227 spin_unlock_irq(&dev->lock);
1228 return mask;
1229 }
1230
1231 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1232 {
1233 struct dev_data *dev = fd->private_data;
1234 struct usb_gadget *gadget = dev->gadget;
1235 long ret = -ENOTTY;
1236
1237 if (gadget->ops->ioctl)
1238 ret = gadget->ops->ioctl (gadget, code, value);
1239
1240 return ret;
1241 }
1242
1243 /*----------------------------------------------------------------------*/
1244
1245 /* The in-kernel gadget driver handles most ep0 issues, in particular
1246 * enumerating the single configuration (as provided from user space).
1247 *
1248 * Unrecognized ep0 requests may be handled in user space.
1249 */
1250
1251 static void make_qualifier (struct dev_data *dev)
1252 {
1253 struct usb_qualifier_descriptor qual;
1254 struct usb_device_descriptor *desc;
1255
1256 qual.bLength = sizeof qual;
1257 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1258 qual.bcdUSB = cpu_to_le16 (0x0200);
1259
1260 desc = dev->dev;
1261 qual.bDeviceClass = desc->bDeviceClass;
1262 qual.bDeviceSubClass = desc->bDeviceSubClass;
1263 qual.bDeviceProtocol = desc->bDeviceProtocol;
1264
1265 /* assumes ep0 uses the same value for both speeds ... */
1266 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1267
1268 qual.bNumConfigurations = 1;
1269 qual.bRESERVED = 0;
1270
1271 memcpy (dev->rbuf, &qual, sizeof qual);
1272 }
1273
1274 static int
1275 config_buf (struct dev_data *dev, u8 type, unsigned index)
1276 {
1277 int len;
1278 int hs = 0;
1279
1280 /* only one configuration */
1281 if (index > 0)
1282 return -EINVAL;
1283
1284 if (gadget_is_dualspeed(dev->gadget)) {
1285 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1286 if (type == USB_DT_OTHER_SPEED_CONFIG)
1287 hs = !hs;
1288 }
1289 if (hs) {
1290 dev->req->buf = dev->hs_config;
1291 len = le16_to_cpu(dev->hs_config->wTotalLength);
1292 } else {
1293 dev->req->buf = dev->config;
1294 len = le16_to_cpu(dev->config->wTotalLength);
1295 }
1296 ((u8 *)dev->req->buf) [1] = type;
1297 return len;
1298 }
1299
1300 static int
1301 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1302 {
1303 struct dev_data *dev = get_gadget_data (gadget);
1304 struct usb_request *req = dev->req;
1305 int value = -EOPNOTSUPP;
1306 struct usb_gadgetfs_event *event;
1307 u16 w_value = le16_to_cpu(ctrl->wValue);
1308 u16 w_length = le16_to_cpu(ctrl->wLength);
1309
1310 spin_lock (&dev->lock);
1311 dev->setup_abort = 0;
1312 if (dev->state == STATE_DEV_UNCONNECTED) {
1313 if (gadget_is_dualspeed(gadget)
1314 && gadget->speed == USB_SPEED_HIGH
1315 && dev->hs_config == NULL) {
1316 spin_unlock(&dev->lock);
1317 ERROR (dev, "no high speed config??\n");
1318 return -EINVAL;
1319 }
1320
1321 dev->state = STATE_DEV_CONNECTED;
1322
1323 INFO (dev, "connected\n");
1324 event = next_event (dev, GADGETFS_CONNECT);
1325 event->u.speed = gadget->speed;
1326 ep0_readable (dev);
1327
1328 /* host may have given up waiting for response. we can miss control
1329 * requests handled lower down (device/endpoint status and features);
1330 * then ep0_{read,write} will report the wrong status. controller
1331 * driver will have aborted pending i/o.
1332 */
1333 } else if (dev->state == STATE_DEV_SETUP)
1334 dev->setup_abort = 1;
1335
1336 req->buf = dev->rbuf;
1337 req->context = NULL;
1338 value = -EOPNOTSUPP;
1339 switch (ctrl->bRequest) {
1340
1341 case USB_REQ_GET_DESCRIPTOR:
1342 if (ctrl->bRequestType != USB_DIR_IN)
1343 goto unrecognized;
1344 switch (w_value >> 8) {
1345
1346 case USB_DT_DEVICE:
1347 value = min (w_length, (u16) sizeof *dev->dev);
1348 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1349 req->buf = dev->dev;
1350 break;
1351 case USB_DT_DEVICE_QUALIFIER:
1352 if (!dev->hs_config)
1353 break;
1354 value = min (w_length, (u16)
1355 sizeof (struct usb_qualifier_descriptor));
1356 make_qualifier (dev);
1357 break;
1358 case USB_DT_OTHER_SPEED_CONFIG:
1359 // FALLTHROUGH
1360 case USB_DT_CONFIG:
1361 value = config_buf (dev,
1362 w_value >> 8,
1363 w_value & 0xff);
1364 if (value >= 0)
1365 value = min (w_length, (u16) value);
1366 break;
1367 case USB_DT_STRING:
1368 goto unrecognized;
1369
1370 default: // all others are errors
1371 break;
1372 }
1373 break;
1374
1375 /* currently one config, two speeds */
1376 case USB_REQ_SET_CONFIGURATION:
1377 if (ctrl->bRequestType != 0)
1378 goto unrecognized;
1379 if (0 == (u8) w_value) {
1380 value = 0;
1381 dev->current_config = 0;
1382 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1383 // user mode expected to disable endpoints
1384 } else {
1385 u8 config, power;
1386
1387 if (gadget_is_dualspeed(gadget)
1388 && gadget->speed == USB_SPEED_HIGH) {
1389 config = dev->hs_config->bConfigurationValue;
1390 power = dev->hs_config->bMaxPower;
1391 } else {
1392 config = dev->config->bConfigurationValue;
1393 power = dev->config->bMaxPower;
1394 }
1395
1396 if (config == (u8) w_value) {
1397 value = 0;
1398 dev->current_config = config;
1399 usb_gadget_vbus_draw(gadget, 2 * power);
1400 }
1401 }
1402
1403 /* report SET_CONFIGURATION like any other control request,
1404 * except that usermode may not stall this. the next
1405 * request mustn't be allowed start until this finishes:
1406 * endpoints and threads set up, etc.
1407 *
1408 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1409 * has bad/racey automagic that prevents synchronizing here.
1410 * even kernel mode drivers often miss them.
1411 */
1412 if (value == 0) {
1413 INFO (dev, "configuration #%d\n", dev->current_config);
1414 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1415 if (dev->usermode_setup) {
1416 dev->setup_can_stall = 0;
1417 goto delegate;
1418 }
1419 }
1420 break;
1421
1422 #ifndef CONFIG_USB_PXA25X
1423 /* PXA automagically handles this request too */
1424 case USB_REQ_GET_CONFIGURATION:
1425 if (ctrl->bRequestType != 0x80)
1426 goto unrecognized;
1427 *(u8 *)req->buf = dev->current_config;
1428 value = min (w_length, (u16) 1);
1429 break;
1430 #endif
1431
1432 default:
1433 unrecognized:
1434 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1435 dev->usermode_setup ? "delegate" : "fail",
1436 ctrl->bRequestType, ctrl->bRequest,
1437 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1438
1439 /* if there's an ep0 reader, don't stall */
1440 if (dev->usermode_setup) {
1441 dev->setup_can_stall = 1;
1442 delegate:
1443 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1444 ? 1 : 0;
1445 dev->setup_wLength = w_length;
1446 dev->setup_out_ready = 0;
1447 dev->setup_out_error = 0;
1448 value = 0;
1449
1450 /* read DATA stage for OUT right away */
1451 if (unlikely (!dev->setup_in && w_length)) {
1452 value = setup_req (gadget->ep0, dev->req,
1453 w_length);
1454 if (value < 0)
1455 break;
1456 value = usb_ep_queue (gadget->ep0, dev->req,
1457 GFP_ATOMIC);
1458 if (value < 0) {
1459 clean_req (gadget->ep0, dev->req);
1460 break;
1461 }
1462
1463 /* we can't currently stall these */
1464 dev->setup_can_stall = 0;
1465 }
1466
1467 /* state changes when reader collects event */
1468 event = next_event (dev, GADGETFS_SETUP);
1469 event->u.setup = *ctrl;
1470 ep0_readable (dev);
1471 spin_unlock (&dev->lock);
1472 return 0;
1473 }
1474 }
1475
1476 /* proceed with data transfer and status phases? */
1477 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1478 req->length = value;
1479 req->zero = value < w_length;
1480 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1481 if (value < 0) {
1482 DBG (dev, "ep_queue --> %d\n", value);
1483 req->status = 0;
1484 }
1485 }
1486
1487 /* device stalls when value < 0 */
1488 spin_unlock (&dev->lock);
1489 return value;
1490 }
1491
1492 static void destroy_ep_files (struct dev_data *dev)
1493 {
1494 DBG (dev, "%s %d\n", __func__, dev->state);
1495
1496 /* dev->state must prevent interference */
1497 spin_lock_irq (&dev->lock);
1498 while (!list_empty(&dev->epfiles)) {
1499 struct ep_data *ep;
1500 struct inode *parent;
1501 struct dentry *dentry;
1502
1503 /* break link to FS */
1504 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1505 list_del_init (&ep->epfiles);
1506 dentry = ep->dentry;
1507 ep->dentry = NULL;
1508 parent = d_inode(dentry->d_parent);
1509
1510 /* break link to controller */
1511 if (ep->state == STATE_EP_ENABLED)
1512 (void) usb_ep_disable (ep->ep);
1513 ep->state = STATE_EP_UNBOUND;
1514 usb_ep_free_request (ep->ep, ep->req);
1515 ep->ep = NULL;
1516 wake_up (&ep->wait);
1517 put_ep (ep);
1518
1519 spin_unlock_irq (&dev->lock);
1520
1521 /* break link to dcache */
1522 mutex_lock (&parent->i_mutex);
1523 d_delete (dentry);
1524 dput (dentry);
1525 mutex_unlock (&parent->i_mutex);
1526
1527 spin_lock_irq (&dev->lock);
1528 }
1529 spin_unlock_irq (&dev->lock);
1530 }
1531
1532
1533 static struct dentry *
1534 gadgetfs_create_file (struct super_block *sb, char const *name,
1535 void *data, const struct file_operations *fops);
1536
1537 static int activate_ep_files (struct dev_data *dev)
1538 {
1539 struct usb_ep *ep;
1540 struct ep_data *data;
1541
1542 gadget_for_each_ep (ep, dev->gadget) {
1543
1544 data = kzalloc(sizeof(*data), GFP_KERNEL);
1545 if (!data)
1546 goto enomem0;
1547 data->state = STATE_EP_DISABLED;
1548 mutex_init(&data->lock);
1549 init_waitqueue_head (&data->wait);
1550
1551 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1552 atomic_set (&data->count, 1);
1553 data->dev = dev;
1554 get_dev (dev);
1555
1556 data->ep = ep;
1557 ep->driver_data = data;
1558
1559 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1560 if (!data->req)
1561 goto enomem1;
1562
1563 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1564 data, &ep_io_operations);
1565 if (!data->dentry)
1566 goto enomem2;
1567 list_add_tail (&data->epfiles, &dev->epfiles);
1568 }
1569 return 0;
1570
1571 enomem2:
1572 usb_ep_free_request (ep, data->req);
1573 enomem1:
1574 put_dev (dev);
1575 kfree (data);
1576 enomem0:
1577 DBG (dev, "%s enomem\n", __func__);
1578 destroy_ep_files (dev);
1579 return -ENOMEM;
1580 }
1581
1582 static void
1583 gadgetfs_unbind (struct usb_gadget *gadget)
1584 {
1585 struct dev_data *dev = get_gadget_data (gadget);
1586
1587 DBG (dev, "%s\n", __func__);
1588
1589 spin_lock_irq (&dev->lock);
1590 dev->state = STATE_DEV_UNBOUND;
1591 spin_unlock_irq (&dev->lock);
1592
1593 destroy_ep_files (dev);
1594 gadget->ep0->driver_data = NULL;
1595 set_gadget_data (gadget, NULL);
1596
1597 /* we've already been disconnected ... no i/o is active */
1598 if (dev->req)
1599 usb_ep_free_request (gadget->ep0, dev->req);
1600 DBG (dev, "%s done\n", __func__);
1601 put_dev (dev);
1602 }
1603
1604 static struct dev_data *the_device;
1605
1606 static int gadgetfs_bind(struct usb_gadget *gadget,
1607 struct usb_gadget_driver *driver)
1608 {
1609 struct dev_data *dev = the_device;
1610
1611 if (!dev)
1612 return -ESRCH;
1613 if (0 != strcmp (CHIP, gadget->name)) {
1614 pr_err("%s expected %s controller not %s\n",
1615 shortname, CHIP, gadget->name);
1616 return -ENODEV;
1617 }
1618
1619 set_gadget_data (gadget, dev);
1620 dev->gadget = gadget;
1621 gadget->ep0->driver_data = dev;
1622
1623 /* preallocate control response and buffer */
1624 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1625 if (!dev->req)
1626 goto enomem;
1627 dev->req->context = NULL;
1628 dev->req->complete = epio_complete;
1629
1630 if (activate_ep_files (dev) < 0)
1631 goto enomem;
1632
1633 INFO (dev, "bound to %s driver\n", gadget->name);
1634 spin_lock_irq(&dev->lock);
1635 dev->state = STATE_DEV_UNCONNECTED;
1636 spin_unlock_irq(&dev->lock);
1637 get_dev (dev);
1638 return 0;
1639
1640 enomem:
1641 gadgetfs_unbind (gadget);
1642 return -ENOMEM;
1643 }
1644
1645 static void
1646 gadgetfs_disconnect (struct usb_gadget *gadget)
1647 {
1648 struct dev_data *dev = get_gadget_data (gadget);
1649 unsigned long flags;
1650
1651 spin_lock_irqsave (&dev->lock, flags);
1652 if (dev->state == STATE_DEV_UNCONNECTED)
1653 goto exit;
1654 dev->state = STATE_DEV_UNCONNECTED;
1655
1656 INFO (dev, "disconnected\n");
1657 next_event (dev, GADGETFS_DISCONNECT);
1658 ep0_readable (dev);
1659 exit:
1660 spin_unlock_irqrestore (&dev->lock, flags);
1661 }
1662
1663 static void
1664 gadgetfs_suspend (struct usb_gadget *gadget)
1665 {
1666 struct dev_data *dev = get_gadget_data (gadget);
1667
1668 INFO (dev, "suspended from state %d\n", dev->state);
1669 spin_lock (&dev->lock);
1670 switch (dev->state) {
1671 case STATE_DEV_SETUP: // VERY odd... host died??
1672 case STATE_DEV_CONNECTED:
1673 case STATE_DEV_UNCONNECTED:
1674 next_event (dev, GADGETFS_SUSPEND);
1675 ep0_readable (dev);
1676 /* FALLTHROUGH */
1677 default:
1678 break;
1679 }
1680 spin_unlock (&dev->lock);
1681 }
1682
1683 static struct usb_gadget_driver gadgetfs_driver = {
1684 .function = (char *) driver_desc,
1685 .bind = gadgetfs_bind,
1686 .unbind = gadgetfs_unbind,
1687 .setup = gadgetfs_setup,
1688 .reset = gadgetfs_disconnect,
1689 .disconnect = gadgetfs_disconnect,
1690 .suspend = gadgetfs_suspend,
1691
1692 .driver = {
1693 .name = (char *) shortname,
1694 },
1695 };
1696
1697 /*----------------------------------------------------------------------*/
1698
1699 static void gadgetfs_nop(struct usb_gadget *arg) { }
1700
1701 static int gadgetfs_probe(struct usb_gadget *gadget,
1702 struct usb_gadget_driver *driver)
1703 {
1704 CHIP = gadget->name;
1705 return -EISNAM;
1706 }
1707
1708 static struct usb_gadget_driver probe_driver = {
1709 .max_speed = USB_SPEED_HIGH,
1710 .bind = gadgetfs_probe,
1711 .unbind = gadgetfs_nop,
1712 .setup = (void *)gadgetfs_nop,
1713 .disconnect = gadgetfs_nop,
1714 .driver = {
1715 .name = "nop",
1716 },
1717 };
1718
1719
1720 /* DEVICE INITIALIZATION
1721 *
1722 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1723 * status = write (fd, descriptors, sizeof descriptors)
1724 *
1725 * That write establishes the device configuration, so the kernel can
1726 * bind to the controller ... guaranteeing it can handle enumeration
1727 * at all necessary speeds. Descriptor order is:
1728 *
1729 * . message tag (u32, host order) ... for now, must be zero; it
1730 * would change to support features like multi-config devices
1731 * . full/low speed config ... all wTotalLength bytes (with interface,
1732 * class, altsetting, endpoint, and other descriptors)
1733 * . high speed config ... all descriptors, for high speed operation;
1734 * this one's optional except for high-speed hardware
1735 * . device descriptor
1736 *
1737 * Endpoints are not yet enabled. Drivers must wait until device
1738 * configuration and interface altsetting changes create
1739 * the need to configure (or unconfigure) them.
1740 *
1741 * After initialization, the device stays active for as long as that
1742 * $CHIP file is open. Events must then be read from that descriptor,
1743 * such as configuration notifications.
1744 */
1745
1746 static int is_valid_config (struct usb_config_descriptor *config)
1747 {
1748 return config->bDescriptorType == USB_DT_CONFIG
1749 && config->bLength == USB_DT_CONFIG_SIZE
1750 && config->bConfigurationValue != 0
1751 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1752 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1753 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1754 /* FIXME check lengths: walk to end */
1755 }
1756
1757 static ssize_t
1758 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1759 {
1760 struct dev_data *dev = fd->private_data;
1761 ssize_t value = len, length = len;
1762 unsigned total;
1763 u32 tag;
1764 char *kbuf;
1765
1766 spin_lock_irq(&dev->lock);
1767 if (dev->state > STATE_DEV_OPENED) {
1768 value = ep0_write(fd, buf, len, ptr);
1769 spin_unlock_irq(&dev->lock);
1770 return value;
1771 }
1772 spin_unlock_irq(&dev->lock);
1773
1774 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1775 return -EINVAL;
1776
1777 /* we might need to change message format someday */
1778 if (copy_from_user (&tag, buf, 4))
1779 return -EFAULT;
1780 if (tag != 0)
1781 return -EINVAL;
1782 buf += 4;
1783 length -= 4;
1784
1785 kbuf = memdup_user(buf, length);
1786 if (IS_ERR(kbuf))
1787 return PTR_ERR(kbuf);
1788
1789 spin_lock_irq (&dev->lock);
1790 value = -EINVAL;
1791 if (dev->buf)
1792 goto fail;
1793 dev->buf = kbuf;
1794
1795 /* full or low speed config */
1796 dev->config = (void *) kbuf;
1797 total = le16_to_cpu(dev->config->wTotalLength);
1798 if (!is_valid_config (dev->config) || total >= length)
1799 goto fail;
1800 kbuf += total;
1801 length -= total;
1802
1803 /* optional high speed config */
1804 if (kbuf [1] == USB_DT_CONFIG) {
1805 dev->hs_config = (void *) kbuf;
1806 total = le16_to_cpu(dev->hs_config->wTotalLength);
1807 if (!is_valid_config (dev->hs_config) || total >= length)
1808 goto fail;
1809 kbuf += total;
1810 length -= total;
1811 }
1812
1813 /* could support multiple configs, using another encoding! */
1814
1815 /* device descriptor (tweaked for paranoia) */
1816 if (length != USB_DT_DEVICE_SIZE)
1817 goto fail;
1818 dev->dev = (void *)kbuf;
1819 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1820 || dev->dev->bDescriptorType != USB_DT_DEVICE
1821 || dev->dev->bNumConfigurations != 1)
1822 goto fail;
1823 dev->dev->bNumConfigurations = 1;
1824 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1825
1826 /* triggers gadgetfs_bind(); then we can enumerate. */
1827 spin_unlock_irq (&dev->lock);
1828 if (dev->hs_config)
1829 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1830 else
1831 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1832
1833 value = usb_gadget_probe_driver(&gadgetfs_driver);
1834 if (value != 0) {
1835 kfree (dev->buf);
1836 dev->buf = NULL;
1837 } else {
1838 /* at this point "good" hardware has for the first time
1839 * let the USB the host see us. alternatively, if users
1840 * unplug/replug that will clear all the error state.
1841 *
1842 * note: everything running before here was guaranteed
1843 * to choke driver model style diagnostics. from here
1844 * on, they can work ... except in cleanup paths that
1845 * kick in after the ep0 descriptor is closed.
1846 */
1847 value = len;
1848 }
1849 return value;
1850
1851 fail:
1852 spin_unlock_irq (&dev->lock);
1853 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1854 kfree (dev->buf);
1855 dev->buf = NULL;
1856 return value;
1857 }
1858
1859 static int
1860 dev_open (struct inode *inode, struct file *fd)
1861 {
1862 struct dev_data *dev = inode->i_private;
1863 int value = -EBUSY;
1864
1865 spin_lock_irq(&dev->lock);
1866 if (dev->state == STATE_DEV_DISABLED) {
1867 dev->ev_next = 0;
1868 dev->state = STATE_DEV_OPENED;
1869 fd->private_data = dev;
1870 get_dev (dev);
1871 value = 0;
1872 }
1873 spin_unlock_irq(&dev->lock);
1874 return value;
1875 }
1876
1877 static const struct file_operations ep0_operations = {
1878 .llseek = no_llseek,
1879
1880 .open = dev_open,
1881 .read = ep0_read,
1882 .write = dev_config,
1883 .fasync = ep0_fasync,
1884 .poll = ep0_poll,
1885 .unlocked_ioctl = dev_ioctl,
1886 .release = dev_release,
1887 };
1888
1889 /*----------------------------------------------------------------------*/
1890
1891 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1892 *
1893 * Mounting the filesystem creates a controller file, used first for
1894 * device configuration then later for event monitoring.
1895 */
1896
1897
1898 /* FIXME PAM etc could set this security policy without mount options
1899 * if epfiles inherited ownership and permissons from ep0 ...
1900 */
1901
1902 static unsigned default_uid;
1903 static unsigned default_gid;
1904 static unsigned default_perm = S_IRUSR | S_IWUSR;
1905
1906 module_param (default_uid, uint, 0644);
1907 module_param (default_gid, uint, 0644);
1908 module_param (default_perm, uint, 0644);
1909
1910
1911 static struct inode *
1912 gadgetfs_make_inode (struct super_block *sb,
1913 void *data, const struct file_operations *fops,
1914 int mode)
1915 {
1916 struct inode *inode = new_inode (sb);
1917
1918 if (inode) {
1919 inode->i_ino = get_next_ino();
1920 inode->i_mode = mode;
1921 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1922 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1923 inode->i_atime = inode->i_mtime = inode->i_ctime
1924 = CURRENT_TIME;
1925 inode->i_private = data;
1926 inode->i_fop = fops;
1927 }
1928 return inode;
1929 }
1930
1931 /* creates in fs root directory, so non-renamable and non-linkable.
1932 * so inode and dentry are paired, until device reconfig.
1933 */
1934 static struct dentry *
1935 gadgetfs_create_file (struct super_block *sb, char const *name,
1936 void *data, const struct file_operations *fops)
1937 {
1938 struct dentry *dentry;
1939 struct inode *inode;
1940
1941 dentry = d_alloc_name(sb->s_root, name);
1942 if (!dentry)
1943 return NULL;
1944
1945 inode = gadgetfs_make_inode (sb, data, fops,
1946 S_IFREG | (default_perm & S_IRWXUGO));
1947 if (!inode) {
1948 dput(dentry);
1949 return NULL;
1950 }
1951 d_add (dentry, inode);
1952 return dentry;
1953 }
1954
1955 static const struct super_operations gadget_fs_operations = {
1956 .statfs = simple_statfs,
1957 .drop_inode = generic_delete_inode,
1958 };
1959
1960 static int
1961 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
1962 {
1963 struct inode *inode;
1964 struct dev_data *dev;
1965
1966 if (the_device)
1967 return -ESRCH;
1968
1969 /* fake probe to determine $CHIP */
1970 CHIP = NULL;
1971 usb_gadget_probe_driver(&probe_driver);
1972 if (!CHIP)
1973 return -ENODEV;
1974
1975 /* superblock */
1976 sb->s_blocksize = PAGE_CACHE_SIZE;
1977 sb->s_blocksize_bits = PAGE_CACHE_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 }
2033
2034 /*----------------------------------------------------------------------*/
2035
2036 static struct file_system_type gadgetfs_type = {
2037 .owner = THIS_MODULE,
2038 .name = shortname,
2039 .mount = gadgetfs_mount,
2040 .kill_sb = gadgetfs_kill_sb,
2041 };
2042 MODULE_ALIAS_FS("gadgetfs");
2043
2044 /*----------------------------------------------------------------------*/
2045
2046 static int __init init (void)
2047 {
2048 int status;
2049
2050 status = register_filesystem (&gadgetfs_type);
2051 if (status == 0)
2052 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2053 shortname, driver_desc);
2054 return status;
2055 }
2056 module_init (init);
2057
2058 static void __exit cleanup (void)
2059 {
2060 pr_debug ("unregister %s\n", shortname);
2061 unregister_filesystem (&gadgetfs_type);
2062 }
2063 module_exit (cleanup);
2064
Linux kernel - Deliverables
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