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Linux 4.2.1
[linux/fpc-iii.git] / drivers / usb / gadget / legacy / inode.c
blobf454c7af489ce050dba446a1a5a6b292ad179644
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 {
773 ep = data->ep;
774 if (ep == NULL) {
775 value = -ENODEV;
776 goto gone;
777 }
778 }
779 switch (data->dev->gadget->speed) {
780 case USB_SPEED_LOW:
781 case USB_SPEED_FULL:
782 ep->desc = &data->desc;
783 break;
784 case USB_SPEED_HIGH:
785 /* fails if caller didn't provide that descriptor... */
786 ep->desc = &data->hs_desc;
787 break;
788 default:
789 DBG(data->dev, "unconnected, %s init abandoned\n",
790 data->name);
791 value = -EINVAL;
792 goto gone;
793 }
794 value = usb_ep_enable(ep);
795 if (value == 0) {
796 data->state = STATE_EP_ENABLED;
797 value = length;
798 }
799 gone:
800 spin_unlock_irq (&data->dev->lock);
801 if (value < 0) {
802 fail:
803 data->desc.bDescriptorType = 0;
804 data->hs_desc.bDescriptorType = 0;
805 }
806 return value;
807 fail0:
808 value = -EINVAL;
809 goto fail;
810 }
811
812 static int
813 ep_open (struct inode *inode, struct file *fd)
814 {
815 struct ep_data *data = inode->i_private;
816 int value = -EBUSY;
817
818 if (mutex_lock_interruptible(&data->lock) != 0)
819 return -EINTR;
820 spin_lock_irq (&data->dev->lock);
821 if (data->dev->state == STATE_DEV_UNBOUND)
822 value = -ENOENT;
823 else if (data->state == STATE_EP_DISABLED) {
824 value = 0;
825 data->state = STATE_EP_READY;
826 get_ep (data);
827 fd->private_data = data;
828 VDEBUG (data->dev, "%s ready\n", data->name);
829 } else
830 DBG (data->dev, "%s state %d\n",
831 data->name, data->state);
832 spin_unlock_irq (&data->dev->lock);
833 mutex_unlock(&data->lock);
834 return value;
835 }
836
837 /*----------------------------------------------------------------------*/
838
839 /* EP0 IMPLEMENTATION can be partly in userspace.
840 *
841 * Drivers that use this facility receive various events, including
842 * control requests the kernel doesn't handle. Drivers that don't
843 * use this facility may be too simple-minded for real applications.
844 */
845
846 static inline void ep0_readable (struct dev_data *dev)
847 {
848 wake_up (&dev->wait);
849 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
850 }
851
852 static void clean_req (struct usb_ep *ep, struct usb_request *req)
853 {
854 struct dev_data *dev = ep->driver_data;
855
856 if (req->buf != dev->rbuf) {
857 kfree(req->buf);
858 req->buf = dev->rbuf;
859 }
860 req->complete = epio_complete;
861 dev->setup_out_ready = 0;
862 }
863
864 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
865 {
866 struct dev_data *dev = ep->driver_data;
867 unsigned long flags;
868 int free = 1;
869
870 /* for control OUT, data must still get to userspace */
871 spin_lock_irqsave(&dev->lock, flags);
872 if (!dev->setup_in) {
873 dev->setup_out_error = (req->status != 0);
874 if (!dev->setup_out_error)
875 free = 0;
876 dev->setup_out_ready = 1;
877 ep0_readable (dev);
878 }
879
880 /* clean up as appropriate */
881 if (free && req->buf != &dev->rbuf)
882 clean_req (ep, req);
883 req->complete = epio_complete;
884 spin_unlock_irqrestore(&dev->lock, flags);
885 }
886
887 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
888 {
889 struct dev_data *dev = ep->driver_data;
890
891 if (dev->setup_out_ready) {
892 DBG (dev, "ep0 request busy!\n");
893 return -EBUSY;
894 }
895 if (len > sizeof (dev->rbuf))
896 req->buf = kmalloc(len, GFP_ATOMIC);
897 if (req->buf == NULL) {
898 req->buf = dev->rbuf;
899 return -ENOMEM;
900 }
901 req->complete = ep0_complete;
902 req->length = len;
903 req->zero = 0;
904 return 0;
905 }
906
907 static ssize_t
908 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
909 {
910 struct dev_data *dev = fd->private_data;
911 ssize_t retval;
912 enum ep0_state state;
913
914 spin_lock_irq (&dev->lock);
915 if (dev->state <= STATE_DEV_OPENED) {
916 retval = -EINVAL;
917 goto done;
918 }
919
920 /* report fd mode change before acting on it */
921 if (dev->setup_abort) {
922 dev->setup_abort = 0;
923 retval = -EIDRM;
924 goto done;
925 }
926
927 /* control DATA stage */
928 if ((state = dev->state) == STATE_DEV_SETUP) {
929
930 if (dev->setup_in) { /* stall IN */
931 VDEBUG(dev, "ep0in stall\n");
932 (void) usb_ep_set_halt (dev->gadget->ep0);
933 retval = -EL2HLT;
934 dev->state = STATE_DEV_CONNECTED;
935
936 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
937 struct usb_ep *ep = dev->gadget->ep0;
938 struct usb_request *req = dev->req;
939
940 if ((retval = setup_req (ep, req, 0)) == 0)
941 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
942 dev->state = STATE_DEV_CONNECTED;
943
944 /* assume that was SET_CONFIGURATION */
945 if (dev->current_config) {
946 unsigned power;
947
948 if (gadget_is_dualspeed(dev->gadget)
949 && (dev->gadget->speed
950 == USB_SPEED_HIGH))
951 power = dev->hs_config->bMaxPower;
952 else
953 power = dev->config->bMaxPower;
954 usb_gadget_vbus_draw(dev->gadget, 2 * power);
955 }
956
957 } else { /* collect OUT data */
958 if ((fd->f_flags & O_NONBLOCK) != 0
959 && !dev->setup_out_ready) {
960 retval = -EAGAIN;
961 goto done;
962 }
963 spin_unlock_irq (&dev->lock);
964 retval = wait_event_interruptible (dev->wait,
965 dev->setup_out_ready != 0);
966
967 /* FIXME state could change from under us */
968 spin_lock_irq (&dev->lock);
969 if (retval)
970 goto done;
971
972 if (dev->state != STATE_DEV_SETUP) {
973 retval = -ECANCELED;
974 goto done;
975 }
976 dev->state = STATE_DEV_CONNECTED;
977
978 if (dev->setup_out_error)
979 retval = -EIO;
980 else {
981 len = min (len, (size_t)dev->req->actual);
982 // FIXME don't call this with the spinlock held ...
983 if (copy_to_user (buf, dev->req->buf, len))
984 retval = -EFAULT;
985 else
986 retval = len;
987 clean_req (dev->gadget->ep0, dev->req);
988 /* NOTE userspace can't yet choose to stall */
989 }
990 }
991 goto done;
992 }
993
994 /* else normal: return event data */
995 if (len < sizeof dev->event [0]) {
996 retval = -EINVAL;
997 goto done;
998 }
999 len -= len % sizeof (struct usb_gadgetfs_event);
1000 dev->usermode_setup = 1;
1001
1002 scan:
1003 /* return queued events right away */
1004 if (dev->ev_next != 0) {
1005 unsigned i, n;
1006
1007 n = len / sizeof (struct usb_gadgetfs_event);
1008 if (dev->ev_next < n)
1009 n = dev->ev_next;
1010
1011 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1012 for (i = 0; i < n; i++) {
1013 if (dev->event [i].type == GADGETFS_SETUP) {
1014 dev->state = STATE_DEV_SETUP;
1015 n = i + 1;
1016 break;
1017 }
1018 }
1019 spin_unlock_irq (&dev->lock);
1020 len = n * sizeof (struct usb_gadgetfs_event);
1021 if (copy_to_user (buf, &dev->event, len))
1022 retval = -EFAULT;
1023 else
1024 retval = len;
1025 if (len > 0) {
1026 /* NOTE this doesn't guard against broken drivers;
1027 * concurrent ep0 readers may lose events.
1028 */
1029 spin_lock_irq (&dev->lock);
1030 if (dev->ev_next > n) {
1031 memmove(&dev->event[0], &dev->event[n],
1032 sizeof (struct usb_gadgetfs_event)
1033 * (dev->ev_next - n));
1034 }
1035 dev->ev_next -= n;
1036 spin_unlock_irq (&dev->lock);
1037 }
1038 return retval;
1039 }
1040 if (fd->f_flags & O_NONBLOCK) {
1041 retval = -EAGAIN;
1042 goto done;
1043 }
1044
1045 switch (state) {
1046 default:
1047 DBG (dev, "fail %s, state %d\n", __func__, state);
1048 retval = -ESRCH;
1049 break;
1050 case STATE_DEV_UNCONNECTED:
1051 case STATE_DEV_CONNECTED:
1052 spin_unlock_irq (&dev->lock);
1053 DBG (dev, "%s wait\n", __func__);
1054
1055 /* wait for events */
1056 retval = wait_event_interruptible (dev->wait,
1057 dev->ev_next != 0);
1058 if (retval < 0)
1059 return retval;
1060 spin_lock_irq (&dev->lock);
1061 goto scan;
1062 }
1063
1064 done:
1065 spin_unlock_irq (&dev->lock);
1066 return retval;
1067 }
1068
1069 static struct usb_gadgetfs_event *
1070 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1071 {
1072 struct usb_gadgetfs_event *event;
1073 unsigned i;
1074
1075 switch (type) {
1076 /* these events purge the queue */
1077 case GADGETFS_DISCONNECT:
1078 if (dev->state == STATE_DEV_SETUP)
1079 dev->setup_abort = 1;
1080 // FALL THROUGH
1081 case GADGETFS_CONNECT:
1082 dev->ev_next = 0;
1083 break;
1084 case GADGETFS_SETUP: /* previous request timed out */
1085 case GADGETFS_SUSPEND: /* same effect */
1086 /* these events can't be repeated */
1087 for (i = 0; i != dev->ev_next; i++) {
1088 if (dev->event [i].type != type)
1089 continue;
1090 DBG(dev, "discard old event[%d] %d\n", i, type);
1091 dev->ev_next--;
1092 if (i == dev->ev_next)
1093 break;
1094 /* indices start at zero, for simplicity */
1095 memmove (&dev->event [i], &dev->event [i + 1],
1096 sizeof (struct usb_gadgetfs_event)
1097 * (dev->ev_next - i));
1098 }
1099 break;
1100 default:
1101 BUG ();
1102 }
1103 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1104 event = &dev->event [dev->ev_next++];
1105 BUG_ON (dev->ev_next > N_EVENT);
1106 memset (event, 0, sizeof *event);
1107 event->type = type;
1108 return event;
1109 }
1110
1111 static ssize_t
1112 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1113 {
1114 struct dev_data *dev = fd->private_data;
1115 ssize_t retval = -ESRCH;
1116
1117 /* report fd mode change before acting on it */
1118 if (dev->setup_abort) {
1119 dev->setup_abort = 0;
1120 retval = -EIDRM;
1121
1122 /* data and/or status stage for control request */
1123 } else if (dev->state == STATE_DEV_SETUP) {
1124
1125 /* IN DATA+STATUS caller makes len <= wLength */
1126 if (dev->setup_in) {
1127 retval = setup_req (dev->gadget->ep0, dev->req, len);
1128 if (retval == 0) {
1129 dev->state = STATE_DEV_CONNECTED;
1130 spin_unlock_irq (&dev->lock);
1131 if (copy_from_user (dev->req->buf, buf, len))
1132 retval = -EFAULT;
1133 else {
1134 if (len < dev->setup_wLength)
1135 dev->req->zero = 1;
1136 retval = usb_ep_queue (
1137 dev->gadget->ep0, dev->req,
1138 GFP_KERNEL);
1139 }
1140 if (retval < 0) {
1141 spin_lock_irq (&dev->lock);
1142 clean_req (dev->gadget->ep0, dev->req);
1143 spin_unlock_irq (&dev->lock);
1144 } else
1145 retval = len;
1146
1147 return retval;
1148 }
1149
1150 /* can stall some OUT transfers */
1151 } else if (dev->setup_can_stall) {
1152 VDEBUG(dev, "ep0out stall\n");
1153 (void) usb_ep_set_halt (dev->gadget->ep0);
1154 retval = -EL2HLT;
1155 dev->state = STATE_DEV_CONNECTED;
1156 } else {
1157 DBG(dev, "bogus ep0out stall!\n");
1158 }
1159 } else
1160 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1161
1162 return retval;
1163 }
1164
1165 static int
1166 ep0_fasync (int f, struct file *fd, int on)
1167 {
1168 struct dev_data *dev = fd->private_data;
1169 // caller must F_SETOWN before signal delivery happens
1170 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1171 return fasync_helper (f, fd, on, &dev->fasync);
1172 }
1173
1174 static struct usb_gadget_driver gadgetfs_driver;
1175
1176 static int
1177 dev_release (struct inode *inode, struct file *fd)
1178 {
1179 struct dev_data *dev = fd->private_data;
1180
1181 /* closing ep0 === shutdown all */
1182
1183 usb_gadget_unregister_driver (&gadgetfs_driver);
1184
1185 /* at this point "good" hardware has disconnected the
1186 * device from USB; the host won't see it any more.
1187 * alternatively, all host requests will time out.
1188 */
1189
1190 kfree (dev->buf);
1191 dev->buf = NULL;
1192
1193 /* other endpoints were all decoupled from this device */
1194 spin_lock_irq(&dev->lock);
1195 dev->state = STATE_DEV_DISABLED;
1196 spin_unlock_irq(&dev->lock);
1197
1198 put_dev (dev);
1199 return 0;
1200 }
1201
1202 static unsigned int
1203 ep0_poll (struct file *fd, poll_table *wait)
1204 {
1205 struct dev_data *dev = fd->private_data;
1206 int mask = 0;
1207
1208 if (dev->state <= STATE_DEV_OPENED)
1209 return DEFAULT_POLLMASK;
1210
1211 poll_wait(fd, &dev->wait, wait);
1212
1213 spin_lock_irq (&dev->lock);
1214
1215 /* report fd mode change before acting on it */
1216 if (dev->setup_abort) {
1217 dev->setup_abort = 0;
1218 mask = POLLHUP;
1219 goto out;
1220 }
1221
1222 if (dev->state == STATE_DEV_SETUP) {
1223 if (dev->setup_in || dev->setup_can_stall)
1224 mask = POLLOUT;
1225 } else {
1226 if (dev->ev_next != 0)
1227 mask = POLLIN;
1228 }
1229 out:
1230 spin_unlock_irq(&dev->lock);
1231 return mask;
1232 }
1233
1234 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1235 {
1236 struct dev_data *dev = fd->private_data;
1237 struct usb_gadget *gadget = dev->gadget;
1238 long ret = -ENOTTY;
1239
1240 if (gadget->ops->ioctl)
1241 ret = gadget->ops->ioctl (gadget, code, value);
1242
1243 return ret;
1244 }
1245
1246 /*----------------------------------------------------------------------*/
1247
1248 /* The in-kernel gadget driver handles most ep0 issues, in particular
1249 * enumerating the single configuration (as provided from user space).
1250 *
1251 * Unrecognized ep0 requests may be handled in user space.
1252 */
1253
1254 static void make_qualifier (struct dev_data *dev)
1255 {
1256 struct usb_qualifier_descriptor qual;
1257 struct usb_device_descriptor *desc;
1258
1259 qual.bLength = sizeof qual;
1260 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1261 qual.bcdUSB = cpu_to_le16 (0x0200);
1262
1263 desc = dev->dev;
1264 qual.bDeviceClass = desc->bDeviceClass;
1265 qual.bDeviceSubClass = desc->bDeviceSubClass;
1266 qual.bDeviceProtocol = desc->bDeviceProtocol;
1267
1268 /* assumes ep0 uses the same value for both speeds ... */
1269 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1270
1271 qual.bNumConfigurations = 1;
1272 qual.bRESERVED = 0;
1273
1274 memcpy (dev->rbuf, &qual, sizeof qual);
1275 }
1276
1277 static int
1278 config_buf (struct dev_data *dev, u8 type, unsigned index)
1279 {
1280 int len;
1281 int hs = 0;
1282
1283 /* only one configuration */
1284 if (index > 0)
1285 return -EINVAL;
1286
1287 if (gadget_is_dualspeed(dev->gadget)) {
1288 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1289 if (type == USB_DT_OTHER_SPEED_CONFIG)
1290 hs = !hs;
1291 }
1292 if (hs) {
1293 dev->req->buf = dev->hs_config;
1294 len = le16_to_cpu(dev->hs_config->wTotalLength);
1295 } else {
1296 dev->req->buf = dev->config;
1297 len = le16_to_cpu(dev->config->wTotalLength);
1298 }
1299 ((u8 *)dev->req->buf) [1] = type;
1300 return len;
1301 }
1302
1303 static int
1304 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1305 {
1306 struct dev_data *dev = get_gadget_data (gadget);
1307 struct usb_request *req = dev->req;
1308 int value = -EOPNOTSUPP;
1309 struct usb_gadgetfs_event *event;
1310 u16 w_value = le16_to_cpu(ctrl->wValue);
1311 u16 w_length = le16_to_cpu(ctrl->wLength);
1312
1313 spin_lock (&dev->lock);
1314 dev->setup_abort = 0;
1315 if (dev->state == STATE_DEV_UNCONNECTED) {
1316 if (gadget_is_dualspeed(gadget)
1317 && gadget->speed == USB_SPEED_HIGH
1318 && dev->hs_config == NULL) {
1319 spin_unlock(&dev->lock);
1320 ERROR (dev, "no high speed config??\n");
1321 return -EINVAL;
1322 }
1323
1324 dev->state = STATE_DEV_CONNECTED;
1325
1326 INFO (dev, "connected\n");
1327 event = next_event (dev, GADGETFS_CONNECT);
1328 event->u.speed = gadget->speed;
1329 ep0_readable (dev);
1330
1331 /* host may have given up waiting for response. we can miss control
1332 * requests handled lower down (device/endpoint status and features);
1333 * then ep0_{read,write} will report the wrong status. controller
1334 * driver will have aborted pending i/o.
1335 */
1336 } else if (dev->state == STATE_DEV_SETUP)
1337 dev->setup_abort = 1;
1338
1339 req->buf = dev->rbuf;
1340 req->context = NULL;
1341 value = -EOPNOTSUPP;
1342 switch (ctrl->bRequest) {
1343
1344 case USB_REQ_GET_DESCRIPTOR:
1345 if (ctrl->bRequestType != USB_DIR_IN)
1346 goto unrecognized;
1347 switch (w_value >> 8) {
1348
1349 case USB_DT_DEVICE:
1350 value = min (w_length, (u16) sizeof *dev->dev);
1351 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1352 req->buf = dev->dev;
1353 break;
1354 case USB_DT_DEVICE_QUALIFIER:
1355 if (!dev->hs_config)
1356 break;
1357 value = min (w_length, (u16)
1358 sizeof (struct usb_qualifier_descriptor));
1359 make_qualifier (dev);
1360 break;
1361 case USB_DT_OTHER_SPEED_CONFIG:
1362 // FALLTHROUGH
1363 case USB_DT_CONFIG:
1364 value = config_buf (dev,
1365 w_value >> 8,
1366 w_value & 0xff);
1367 if (value >= 0)
1368 value = min (w_length, (u16) value);
1369 break;
1370 case USB_DT_STRING:
1371 goto unrecognized;
1372
1373 default: // all others are errors
1374 break;
1375 }
1376 break;
1377
1378 /* currently one config, two speeds */
1379 case USB_REQ_SET_CONFIGURATION:
1380 if (ctrl->bRequestType != 0)
1381 goto unrecognized;
1382 if (0 == (u8) w_value) {
1383 value = 0;
1384 dev->current_config = 0;
1385 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1386 // user mode expected to disable endpoints
1387 } else {
1388 u8 config, power;
1389
1390 if (gadget_is_dualspeed(gadget)
1391 && gadget->speed == USB_SPEED_HIGH) {
1392 config = dev->hs_config->bConfigurationValue;
1393 power = dev->hs_config->bMaxPower;
1394 } else {
1395 config = dev->config->bConfigurationValue;
1396 power = dev->config->bMaxPower;
1397 }
1398
1399 if (config == (u8) w_value) {
1400 value = 0;
1401 dev->current_config = config;
1402 usb_gadget_vbus_draw(gadget, 2 * power);
1403 }
1404 }
1405
1406 /* report SET_CONFIGURATION like any other control request,
1407 * except that usermode may not stall this. the next
1408 * request mustn't be allowed start until this finishes:
1409 * endpoints and threads set up, etc.
1410 *
1411 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1412 * has bad/racey automagic that prevents synchronizing here.
1413 * even kernel mode drivers often miss them.
1414 */
1415 if (value == 0) {
1416 INFO (dev, "configuration #%d\n", dev->current_config);
1417 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1418 if (dev->usermode_setup) {
1419 dev->setup_can_stall = 0;
1420 goto delegate;
1421 }
1422 }
1423 break;
1424
1425 #ifndef CONFIG_USB_PXA25X
1426 /* PXA automagically handles this request too */
1427 case USB_REQ_GET_CONFIGURATION:
1428 if (ctrl->bRequestType != 0x80)
1429 goto unrecognized;
1430 *(u8 *)req->buf = dev->current_config;
1431 value = min (w_length, (u16) 1);
1432 break;
1433 #endif
1434
1435 default:
1436 unrecognized:
1437 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1438 dev->usermode_setup ? "delegate" : "fail",
1439 ctrl->bRequestType, ctrl->bRequest,
1440 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1441
1442 /* if there's an ep0 reader, don't stall */
1443 if (dev->usermode_setup) {
1444 dev->setup_can_stall = 1;
1445 delegate:
1446 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1447 ? 1 : 0;
1448 dev->setup_wLength = w_length;
1449 dev->setup_out_ready = 0;
1450 dev->setup_out_error = 0;
1451 value = 0;
1452
1453 /* read DATA stage for OUT right away */
1454 if (unlikely (!dev->setup_in && w_length)) {
1455 value = setup_req (gadget->ep0, dev->req,
1456 w_length);
1457 if (value < 0)
1458 break;
1459 value = usb_ep_queue (gadget->ep0, dev->req,
1460 GFP_ATOMIC);
1461 if (value < 0) {
1462 clean_req (gadget->ep0, dev->req);
1463 break;
1464 }
1465
1466 /* we can't currently stall these */
1467 dev->setup_can_stall = 0;
1468 }
1469
1470 /* state changes when reader collects event */
1471 event = next_event (dev, GADGETFS_SETUP);
1472 event->u.setup = *ctrl;
1473 ep0_readable (dev);
1474 spin_unlock (&dev->lock);
1475 return 0;
1476 }
1477 }
1478
1479 /* proceed with data transfer and status phases? */
1480 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1481 req->length = value;
1482 req->zero = value < w_length;
1483 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1484 if (value < 0) {
1485 DBG (dev, "ep_queue --> %d\n", value);
1486 req->status = 0;
1487 }
1488 }
1489
1490 /* device stalls when value < 0 */
1491 spin_unlock (&dev->lock);
1492 return value;
1493 }
1494
1495 static void destroy_ep_files (struct dev_data *dev)
1496 {
1497 DBG (dev, "%s %d\n", __func__, dev->state);
1498
1499 /* dev->state must prevent interference */
1500 spin_lock_irq (&dev->lock);
1501 while (!list_empty(&dev->epfiles)) {
1502 struct ep_data *ep;
1503 struct inode *parent;
1504 struct dentry *dentry;
1505
1506 /* break link to FS */
1507 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1508 list_del_init (&ep->epfiles);
1509 dentry = ep->dentry;
1510 ep->dentry = NULL;
1511 parent = d_inode(dentry->d_parent);
1512
1513 /* break link to controller */
1514 if (ep->state == STATE_EP_ENABLED)
1515 (void) usb_ep_disable (ep->ep);
1516 ep->state = STATE_EP_UNBOUND;
1517 usb_ep_free_request (ep->ep, ep->req);
1518 ep->ep = NULL;
1519 wake_up (&ep->wait);
1520 put_ep (ep);
1521
1522 spin_unlock_irq (&dev->lock);
1523
1524 /* break link to dcache */
1525 mutex_lock (&parent->i_mutex);
1526 d_delete (dentry);
1527 dput (dentry);
1528 mutex_unlock (&parent->i_mutex);
1529
1530 spin_lock_irq (&dev->lock);
1531 }
1532 spin_unlock_irq (&dev->lock);
1533 }
1534
1535
1536 static struct dentry *
1537 gadgetfs_create_file (struct super_block *sb, char const *name,
1538 void *data, const struct file_operations *fops);
1539
1540 static int activate_ep_files (struct dev_data *dev)
1541 {
1542 struct usb_ep *ep;
1543 struct ep_data *data;
1544
1545 gadget_for_each_ep (ep, dev->gadget) {
1546
1547 data = kzalloc(sizeof(*data), GFP_KERNEL);
1548 if (!data)
1549 goto enomem0;
1550 data->state = STATE_EP_DISABLED;
1551 mutex_init(&data->lock);
1552 init_waitqueue_head (&data->wait);
1553
1554 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1555 atomic_set (&data->count, 1);
1556 data->dev = dev;
1557 get_dev (dev);
1558
1559 data->ep = ep;
1560 ep->driver_data = data;
1561
1562 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1563 if (!data->req)
1564 goto enomem1;
1565
1566 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1567 data, &ep_io_operations);
1568 if (!data->dentry)
1569 goto enomem2;
1570 list_add_tail (&data->epfiles, &dev->epfiles);
1571 }
1572 return 0;
1573
1574 enomem2:
1575 usb_ep_free_request (ep, data->req);
1576 enomem1:
1577 put_dev (dev);
1578 kfree (data);
1579 enomem0:
1580 DBG (dev, "%s enomem\n", __func__);
1581 destroy_ep_files (dev);
1582 return -ENOMEM;
1583 }
1584
1585 static void
1586 gadgetfs_unbind (struct usb_gadget *gadget)
1587 {
1588 struct dev_data *dev = get_gadget_data (gadget);
1589
1590 DBG (dev, "%s\n", __func__);
1591
1592 spin_lock_irq (&dev->lock);
1593 dev->state = STATE_DEV_UNBOUND;
1594 spin_unlock_irq (&dev->lock);
1595
1596 destroy_ep_files (dev);
1597 gadget->ep0->driver_data = NULL;
1598 set_gadget_data (gadget, NULL);
1599
1600 /* we've already been disconnected ... no i/o is active */
1601 if (dev->req)
1602 usb_ep_free_request (gadget->ep0, dev->req);
1603 DBG (dev, "%s done\n", __func__);
1604 put_dev (dev);
1605 }
1606
1607 static struct dev_data *the_device;
1608
1609 static int gadgetfs_bind(struct usb_gadget *gadget,
1610 struct usb_gadget_driver *driver)
1611 {
1612 struct dev_data *dev = the_device;
1613
1614 if (!dev)
1615 return -ESRCH;
1616 if (0 != strcmp (CHIP, gadget->name)) {
1617 pr_err("%s expected %s controller not %s\n",
1618 shortname, CHIP, gadget->name);
1619 return -ENODEV;
1620 }
1621
1622 set_gadget_data (gadget, dev);
1623 dev->gadget = gadget;
1624 gadget->ep0->driver_data = dev;
1625
1626 /* preallocate control response and buffer */
1627 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1628 if (!dev->req)
1629 goto enomem;
1630 dev->req->context = NULL;
1631 dev->req->complete = epio_complete;
1632
1633 if (activate_ep_files (dev) < 0)
1634 goto enomem;
1635
1636 INFO (dev, "bound to %s driver\n", gadget->name);
1637 spin_lock_irq(&dev->lock);
1638 dev->state = STATE_DEV_UNCONNECTED;
1639 spin_unlock_irq(&dev->lock);
1640 get_dev (dev);
1641 return 0;
1642
1643 enomem:
1644 gadgetfs_unbind (gadget);
1645 return -ENOMEM;
1646 }
1647
1648 static void
1649 gadgetfs_disconnect (struct usb_gadget *gadget)
1650 {
1651 struct dev_data *dev = get_gadget_data (gadget);
1652 unsigned long flags;
1653
1654 spin_lock_irqsave (&dev->lock, flags);
1655 if (dev->state == STATE_DEV_UNCONNECTED)
1656 goto exit;
1657 dev->state = STATE_DEV_UNCONNECTED;
1658
1659 INFO (dev, "disconnected\n");
1660 next_event (dev, GADGETFS_DISCONNECT);
1661 ep0_readable (dev);
1662 exit:
1663 spin_unlock_irqrestore (&dev->lock, flags);
1664 }
1665
1666 static void
1667 gadgetfs_suspend (struct usb_gadget *gadget)
1668 {
1669 struct dev_data *dev = get_gadget_data (gadget);
1670
1671 INFO (dev, "suspended from state %d\n", dev->state);
1672 spin_lock (&dev->lock);
1673 switch (dev->state) {
1674 case STATE_DEV_SETUP: // VERY odd... host died??
1675 case STATE_DEV_CONNECTED:
1676 case STATE_DEV_UNCONNECTED:
1677 next_event (dev, GADGETFS_SUSPEND);
1678 ep0_readable (dev);
1679 /* FALLTHROUGH */
1680 default:
1681 break;
1682 }
1683 spin_unlock (&dev->lock);
1684 }
1685
1686 static struct usb_gadget_driver gadgetfs_driver = {
1687 .function = (char *) driver_desc,
1688 .bind = gadgetfs_bind,
1689 .unbind = gadgetfs_unbind,
1690 .setup = gadgetfs_setup,
1691 .reset = gadgetfs_disconnect,
1692 .disconnect = gadgetfs_disconnect,
1693 .suspend = gadgetfs_suspend,
1694
1695 .driver = {
1696 .name = (char *) shortname,
1697 },
1698 };
1699
1700 /*----------------------------------------------------------------------*/
1701
1702 static void gadgetfs_nop(struct usb_gadget *arg) { }
1703
1704 static int gadgetfs_probe(struct usb_gadget *gadget,
1705 struct usb_gadget_driver *driver)
1706 {
1707 CHIP = gadget->name;
1708 return -EISNAM;
1709 }
1710
1711 static struct usb_gadget_driver probe_driver = {
1712 .max_speed = USB_SPEED_HIGH,
1713 .bind = gadgetfs_probe,
1714 .unbind = gadgetfs_nop,
1715 .setup = (void *)gadgetfs_nop,
1716 .disconnect = gadgetfs_nop,
1717 .driver = {
1718 .name = "nop",
1719 },
1720 };
1721
1722
1723 /* DEVICE INITIALIZATION
1724 *
1725 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1726 * status = write (fd, descriptors, sizeof descriptors)
1727 *
1728 * That write establishes the device configuration, so the kernel can
1729 * bind to the controller ... guaranteeing it can handle enumeration
1730 * at all necessary speeds. Descriptor order is:
1731 *
1732 * . message tag (u32, host order) ... for now, must be zero; it
1733 * would change to support features like multi-config devices
1734 * . full/low speed config ... all wTotalLength bytes (with interface,
1735 * class, altsetting, endpoint, and other descriptors)
1736 * . high speed config ... all descriptors, for high speed operation;
1737 * this one's optional except for high-speed hardware
1738 * . device descriptor
1739 *
1740 * Endpoints are not yet enabled. Drivers must wait until device
1741 * configuration and interface altsetting changes create
1742 * the need to configure (or unconfigure) them.
1743 *
1744 * After initialization, the device stays active for as long as that
1745 * $CHIP file is open. Events must then be read from that descriptor,
1746 * such as configuration notifications.
1747 */
1748
1749 static int is_valid_config (struct usb_config_descriptor *config)
1750 {
1751 return config->bDescriptorType == USB_DT_CONFIG
1752 && config->bLength == USB_DT_CONFIG_SIZE
1753 && config->bConfigurationValue != 0
1754 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1755 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1756 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1757 /* FIXME check lengths: walk to end */
1758 }
1759
1760 static ssize_t
1761 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1762 {
1763 struct dev_data *dev = fd->private_data;
1764 ssize_t value = len, length = len;
1765 unsigned total;
1766 u32 tag;
1767 char *kbuf;
1768
1769 spin_lock_irq(&dev->lock);
1770 if (dev->state > STATE_DEV_OPENED) {
1771 value = ep0_write(fd, buf, len, ptr);
1772 spin_unlock_irq(&dev->lock);
1773 return value;
1774 }
1775 spin_unlock_irq(&dev->lock);
1776
1777 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1778 return -EINVAL;
1779
1780 /* we might need to change message format someday */
1781 if (copy_from_user (&tag, buf, 4))
1782 return -EFAULT;
1783 if (tag != 0)
1784 return -EINVAL;
1785 buf += 4;
1786 length -= 4;
1787
1788 kbuf = memdup_user(buf, length);
1789 if (IS_ERR(kbuf))
1790 return PTR_ERR(kbuf);
1791
1792 spin_lock_irq (&dev->lock);
1793 value = -EINVAL;
1794 if (dev->buf)
1795 goto fail;
1796 dev->buf = kbuf;
1797
1798 /* full or low speed config */
1799 dev->config = (void *) kbuf;
1800 total = le16_to_cpu(dev->config->wTotalLength);
1801 if (!is_valid_config (dev->config) || total >= length)
1802 goto fail;
1803 kbuf += total;
1804 length -= total;
1805
1806 /* optional high speed config */
1807 if (kbuf [1] == USB_DT_CONFIG) {
1808 dev->hs_config = (void *) kbuf;
1809 total = le16_to_cpu(dev->hs_config->wTotalLength);
1810 if (!is_valid_config (dev->hs_config) || total >= length)
1811 goto fail;
1812 kbuf += total;
1813 length -= total;
1814 }
1815
1816 /* could support multiple configs, using another encoding! */
1817
1818 /* device descriptor (tweaked for paranoia) */
1819 if (length != USB_DT_DEVICE_SIZE)
1820 goto fail;
1821 dev->dev = (void *)kbuf;
1822 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1823 || dev->dev->bDescriptorType != USB_DT_DEVICE
1824 || dev->dev->bNumConfigurations != 1)
1825 goto fail;
1826 dev->dev->bNumConfigurations = 1;
1827 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1828
1829 /* triggers gadgetfs_bind(); then we can enumerate. */
1830 spin_unlock_irq (&dev->lock);
1831 if (dev->hs_config)
1832 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1833 else
1834 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1835
1836 value = usb_gadget_probe_driver(&gadgetfs_driver);
1837 if (value != 0) {
1838 kfree (dev->buf);
1839 dev->buf = NULL;
1840 } else {
1841 /* at this point "good" hardware has for the first time
1842 * let the USB the host see us. alternatively, if users
1843 * unplug/replug that will clear all the error state.
1844 *
1845 * note: everything running before here was guaranteed
1846 * to choke driver model style diagnostics. from here
1847 * on, they can work ... except in cleanup paths that
1848 * kick in after the ep0 descriptor is closed.
1849 */
1850 value = len;
1851 }
1852 return value;
1853
1854 fail:
1855 spin_unlock_irq (&dev->lock);
1856 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1857 kfree (dev->buf);
1858 dev->buf = NULL;
1859 return value;
1860 }
1861
1862 static int
1863 dev_open (struct inode *inode, struct file *fd)
1864 {
1865 struct dev_data *dev = inode->i_private;
1866 int value = -EBUSY;
1867
1868 spin_lock_irq(&dev->lock);
1869 if (dev->state == STATE_DEV_DISABLED) {
1870 dev->ev_next = 0;
1871 dev->state = STATE_DEV_OPENED;
1872 fd->private_data = dev;
1873 get_dev (dev);
1874 value = 0;
1875 }
1876 spin_unlock_irq(&dev->lock);
1877 return value;
1878 }
1879
1880 static const struct file_operations ep0_operations = {
1881 .llseek = no_llseek,
1882
1883 .open = dev_open,
1884 .read = ep0_read,
1885 .write = dev_config,
1886 .fasync = ep0_fasync,
1887 .poll = ep0_poll,
1888 .unlocked_ioctl = dev_ioctl,
1889 .release = dev_release,
1890 };
1891
1892 /*----------------------------------------------------------------------*/
1893
1894 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1895 *
1896 * Mounting the filesystem creates a controller file, used first for
1897 * device configuration then later for event monitoring.
1898 */
1899
1900
1901 /* FIXME PAM etc could set this security policy without mount options
1902 * if epfiles inherited ownership and permissons from ep0 ...
1903 */
1904
1905 static unsigned default_uid;
1906 static unsigned default_gid;
1907 static unsigned default_perm = S_IRUSR | S_IWUSR;
1908
1909 module_param (default_uid, uint, 0644);
1910 module_param (default_gid, uint, 0644);
1911 module_param (default_perm, uint, 0644);
1912
1913
1914 static struct inode *
1915 gadgetfs_make_inode (struct super_block *sb,
1916 void *data, const struct file_operations *fops,
1917 int mode)
1918 {
1919 struct inode *inode = new_inode (sb);
1920
1921 if (inode) {
1922 inode->i_ino = get_next_ino();
1923 inode->i_mode = mode;
1924 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1925 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1926 inode->i_atime = inode->i_mtime = inode->i_ctime
1927 = CURRENT_TIME;
1928 inode->i_private = data;
1929 inode->i_fop = fops;
1930 }
1931 return inode;
1932 }
1933
1934 /* creates in fs root directory, so non-renamable and non-linkable.
1935 * so inode and dentry are paired, until device reconfig.
1936 */
1937 static struct dentry *
1938 gadgetfs_create_file (struct super_block *sb, char const *name,
1939 void *data, const struct file_operations *fops)
1940 {
1941 struct dentry *dentry;
1942 struct inode *inode;
1943
1944 dentry = d_alloc_name(sb->s_root, name);
1945 if (!dentry)
1946 return NULL;
1947
1948 inode = gadgetfs_make_inode (sb, data, fops,
1949 S_IFREG | (default_perm & S_IRWXUGO));
1950 if (!inode) {
1951 dput(dentry);
1952 return NULL;
1953 }
1954 d_add (dentry, inode);
1955 return dentry;
1956 }
1957
1958 static const struct super_operations gadget_fs_operations = {
1959 .statfs = simple_statfs,
1960 .drop_inode = generic_delete_inode,
1961 };
1962
1963 static int
1964 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
1965 {
1966 struct inode *inode;
1967 struct dev_data *dev;
1968
1969 if (the_device)
1970 return -ESRCH;
1971
1972 /* fake probe to determine $CHIP */
1973 CHIP = NULL;
1974 usb_gadget_probe_driver(&probe_driver);
1975 if (!CHIP)
1976 return -ENODEV;
1977
1978 /* superblock */
1979 sb->s_blocksize = PAGE_CACHE_SIZE;
1980 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1981 sb->s_magic = GADGETFS_MAGIC;
1982 sb->s_op = &gadget_fs_operations;
1983 sb->s_time_gran = 1;
1984
1985 /* root inode */
1986 inode = gadgetfs_make_inode (sb,
1987 NULL, &simple_dir_operations,
1988 S_IFDIR | S_IRUGO | S_IXUGO);
1989 if (!inode)
1990 goto Enomem;
1991 inode->i_op = &simple_dir_inode_operations;
1992 if (!(sb->s_root = d_make_root (inode)))
1993 goto Enomem;
1994
1995 /* the ep0 file is named after the controller we expect;
1996 * user mode code can use it for sanity checks, like we do.
1997 */
1998 dev = dev_new ();
1999 if (!dev)
2000 goto Enomem;
2001
2002 dev->sb = sb;
2003 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2004 if (!dev->dentry) {
2005 put_dev(dev);
2006 goto Enomem;
2007 }
2008
2009 /* other endpoint files are available after hardware setup,
2010 * from binding to a controller.
2011 */
2012 the_device = dev;
2013 return 0;
2014
2015 Enomem:
2016 return -ENOMEM;
2017 }
2018
2019 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2020 static struct dentry *
2021 gadgetfs_mount (struct file_system_type *t, int flags,
2022 const char *path, void *opts)
2023 {
2024 return mount_single (t, flags, opts, gadgetfs_fill_super);
2025 }
2026
2027 static void
2028 gadgetfs_kill_sb (struct super_block *sb)
2029 {
2030 kill_litter_super (sb);
2031 if (the_device) {
2032 put_dev (the_device);
2033 the_device = NULL;
2034 }
2035 }
2036
2037 /*----------------------------------------------------------------------*/
2038
2039 static struct file_system_type gadgetfs_type = {
2040 .owner = THIS_MODULE,
2041 .name = shortname,
2042 .mount = gadgetfs_mount,
2043 .kill_sb = gadgetfs_kill_sb,
2044 };
2045 MODULE_ALIAS_FS("gadgetfs");
2046
2047 /*----------------------------------------------------------------------*/
2048
2049 static int __init init (void)
2050 {
2051 int status;
2052
2053 status = register_filesystem (&gadgetfs_type);
2054 if (status == 0)
2055 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2056 shortname, driver_desc);
2057 return status;
2058 }
2059 module_init (init);
2060
2061 static void __exit cleanup (void)
2062 {
2063 pr_debug ("unregister %s\n", shortname);
2064 unregister_filesystem (&gadgetfs_type);
2065 }
2066 module_exit (cleanup);
2067
Linux with added FPC-III support