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Merge tag 'clk' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / usb / gadget / f_fs.c
1 /*
2 * f_fs.c -- user mode file system API for USB composite function controllers
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 * Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
6 *
7 * Based on inode.c (GadgetFS) which was:
8 * Copyright (C) 2003-2004 David Brownell
9 * Copyright (C) 2003 Agilent Technologies
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 */
16
17
18 /* #define DEBUG */
19 /* #define VERBOSE_DEBUG */
20
21 #include <linux/blkdev.h>
22 #include <linux/pagemap.h>
23 #include <linux/export.h>
24 #include <asm/unaligned.h>
25
26 #include <linux/usb/composite.h>
27 #include <linux/usb/functionfs.h>
28
29
30 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
31
32
33 /* Debugging ****************************************************************/
34
35 #ifdef VERBOSE_DEBUG
36 # define pr_vdebug pr_debug
37 # define ffs_dump_mem(prefix, ptr, len) \
38 print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
39 #else
40 # define pr_vdebug(...) do { } while (0)
41 # define ffs_dump_mem(prefix, ptr, len) do { } while (0)
42 #endif /* VERBOSE_DEBUG */
43
44 #define ENTER() pr_vdebug("%s()\n", __func__)
45
46
47 /* The data structure and setup file ****************************************/
48
49 enum ffs_state {
50 /*
51 * Waiting for descriptors and strings.
52 *
53 * In this state no open(2), read(2) or write(2) on epfiles
54 * may succeed (which should not be the problem as there
55 * should be no such files opened in the first place).
56 */
57 FFS_READ_DESCRIPTORS,
58 FFS_READ_STRINGS,
59
60 /*
61 * We've got descriptors and strings. We are or have called
62 * functionfs_ready_callback(). functionfs_bind() may have
63 * been called but we don't know.
64 *
65 * This is the only state in which operations on epfiles may
66 * succeed.
67 */
68 FFS_ACTIVE,
69
70 /*
71 * All endpoints have been closed. This state is also set if
72 * we encounter an unrecoverable error. The only
73 * unrecoverable error is situation when after reading strings
74 * from user space we fail to initialise epfiles or
75 * functionfs_ready_callback() returns with error (<0).
76 *
77 * In this state no open(2), read(2) or write(2) (both on ep0
78 * as well as epfile) may succeed (at this point epfiles are
79 * unlinked and all closed so this is not a problem; ep0 is
80 * also closed but ep0 file exists and so open(2) on ep0 must
81 * fail).
82 */
83 FFS_CLOSING
84 };
85
86
87 enum ffs_setup_state {
88 /* There is no setup request pending. */
89 FFS_NO_SETUP,
90 /*
91 * User has read events and there was a setup request event
92 * there. The next read/write on ep0 will handle the
93 * request.
94 */
95 FFS_SETUP_PENDING,
96 /*
97 * There was event pending but before user space handled it
98 * some other event was introduced which canceled existing
99 * setup. If this state is set read/write on ep0 return
100 * -EIDRM. This state is only set when adding event.
101 */
102 FFS_SETUP_CANCELED
103 };
104
105
106
107 struct ffs_epfile;
108 struct ffs_function;
109
110 struct ffs_data {
111 struct usb_gadget *gadget;
112
113 /*
114 * Protect access read/write operations, only one read/write
115 * at a time. As a consequence protects ep0req and company.
116 * While setup request is being processed (queued) this is
117 * held.
118 */
119 struct mutex mutex;
120
121 /*
122 * Protect access to endpoint related structures (basically
123 * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
124 * endpoint zero.
125 */
126 spinlock_t eps_lock;
127
128 /*
129 * XXX REVISIT do we need our own request? Since we are not
130 * handling setup requests immediately user space may be so
131 * slow that another setup will be sent to the gadget but this
132 * time not to us but another function and then there could be
133 * a race. Is that the case? Or maybe we can use cdev->req
134 * after all, maybe we just need some spinlock for that?
135 */
136 struct usb_request *ep0req; /* P: mutex */
137 struct completion ep0req_completion; /* P: mutex */
138 int ep0req_status; /* P: mutex */
139
140 /* reference counter */
141 atomic_t ref;
142 /* how many files are opened (EP0 and others) */
143 atomic_t opened;
144
145 /* EP0 state */
146 enum ffs_state state;
147
148 /*
149 * Possible transitions:
150 * + FFS_NO_SETUP -> FFS_SETUP_PENDING -- P: ev.waitq.lock
151 * happens only in ep0 read which is P: mutex
152 * + FFS_SETUP_PENDING -> FFS_NO_SETUP -- P: ev.waitq.lock
153 * happens only in ep0 i/o which is P: mutex
154 * + FFS_SETUP_PENDING -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
155 * + FFS_SETUP_CANCELED -> FFS_NO_SETUP -- cmpxchg
156 */
157 enum ffs_setup_state setup_state;
158
159 #define FFS_SETUP_STATE(ffs) \
160 ((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state, \
161 FFS_SETUP_CANCELED, FFS_NO_SETUP))
162
163 /* Events & such. */
164 struct {
165 u8 types[4];
166 unsigned short count;
167 /* XXX REVISIT need to update it in some places, or do we? */
168 unsigned short can_stall;
169 struct usb_ctrlrequest setup;
170
171 wait_queue_head_t waitq;
172 } ev; /* the whole structure, P: ev.waitq.lock */
173
174 /* Flags */
175 unsigned long flags;
176 #define FFS_FL_CALL_CLOSED_CALLBACK 0
177 #define FFS_FL_BOUND 1
178
179 /* Active function */
180 struct ffs_function *func;
181
182 /*
183 * Device name, write once when file system is mounted.
184 * Intended for user to read if she wants.
185 */
186 const char *dev_name;
187 /* Private data for our user (ie. gadget). Managed by user. */
188 void *private_data;
189
190 /* filled by __ffs_data_got_descs() */
191 /*
192 * Real descriptors are 16 bytes after raw_descs (so you need
193 * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
194 * first full speed descriptor). raw_descs_length and
195 * raw_fs_descs_length do not have those 16 bytes added.
196 */
197 const void *raw_descs;
198 unsigned raw_descs_length;
199 unsigned raw_fs_descs_length;
200 unsigned fs_descs_count;
201 unsigned hs_descs_count;
202
203 unsigned short strings_count;
204 unsigned short interfaces_count;
205 unsigned short eps_count;
206 unsigned short _pad1;
207
208 /* filled by __ffs_data_got_strings() */
209 /* ids in stringtabs are set in functionfs_bind() */
210 const void *raw_strings;
211 struct usb_gadget_strings **stringtabs;
212
213 /*
214 * File system's super block, write once when file system is
215 * mounted.
216 */
217 struct super_block *sb;
218
219 /* File permissions, written once when fs is mounted */
220 struct ffs_file_perms {
221 umode_t mode;
222 uid_t uid;
223 gid_t gid;
224 } file_perms;
225
226 /*
227 * The endpoint files, filled by ffs_epfiles_create(),
228 * destroyed by ffs_epfiles_destroy().
229 */
230 struct ffs_epfile *epfiles;
231 };
232
233 /* Reference counter handling */
234 static void ffs_data_get(struct ffs_data *ffs);
235 static void ffs_data_put(struct ffs_data *ffs);
236 /* Creates new ffs_data object. */
237 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
238
239 /* Opened counter handling. */
240 static void ffs_data_opened(struct ffs_data *ffs);
241 static void ffs_data_closed(struct ffs_data *ffs);
242
243 /* Called with ffs->mutex held; take over ownership of data. */
244 static int __must_check
245 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
246 static int __must_check
247 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
248
249
250 /* The function structure ***************************************************/
251
252 struct ffs_ep;
253
254 struct ffs_function {
255 struct usb_configuration *conf;
256 struct usb_gadget *gadget;
257 struct ffs_data *ffs;
258
259 struct ffs_ep *eps;
260 u8 eps_revmap[16];
261 short *interfaces_nums;
262
263 struct usb_function function;
264 };
265
266
267 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
268 {
269 return container_of(f, struct ffs_function, function);
270 }
271
272 static void ffs_func_free(struct ffs_function *func);
273
274 static void ffs_func_eps_disable(struct ffs_function *func);
275 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
276
277 static int ffs_func_bind(struct usb_configuration *,
278 struct usb_function *);
279 static void ffs_func_unbind(struct usb_configuration *,
280 struct usb_function *);
281 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
282 static void ffs_func_disable(struct usb_function *);
283 static int ffs_func_setup(struct usb_function *,
284 const struct usb_ctrlrequest *);
285 static void ffs_func_suspend(struct usb_function *);
286 static void ffs_func_resume(struct usb_function *);
287
288
289 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
290 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
291
292
293 /* The endpoints structures *************************************************/
294
295 struct ffs_ep {
296 struct usb_ep *ep; /* P: ffs->eps_lock */
297 struct usb_request *req; /* P: epfile->mutex */
298
299 /* [0]: full speed, [1]: high speed */
300 struct usb_endpoint_descriptor *descs[2];
301
302 u8 num;
303
304 int status; /* P: epfile->mutex */
305 };
306
307 struct ffs_epfile {
308 /* Protects ep->ep and ep->req. */
309 struct mutex mutex;
310 wait_queue_head_t wait;
311
312 struct ffs_data *ffs;
313 struct ffs_ep *ep; /* P: ffs->eps_lock */
314
315 struct dentry *dentry;
316
317 char name[5];
318
319 unsigned char in; /* P: ffs->eps_lock */
320 unsigned char isoc; /* P: ffs->eps_lock */
321
322 unsigned char _pad;
323 };
324
325 static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
326 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
327
328 static struct inode *__must_check
329 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
330 const struct file_operations *fops,
331 struct dentry **dentry_p);
332
333
334 /* Misc helper functions ****************************************************/
335
336 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
337 __attribute__((warn_unused_result, nonnull));
338 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
339 __attribute__((warn_unused_result, nonnull));
340
341
342 /* Control file aka ep0 *****************************************************/
343
344 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
345 {
346 struct ffs_data *ffs = req->context;
347
348 complete_all(&ffs->ep0req_completion);
349 }
350
351 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
352 {
353 struct usb_request *req = ffs->ep0req;
354 int ret;
355
356 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
357
358 spin_unlock_irq(&ffs->ev.waitq.lock);
359
360 req->buf = data;
361 req->length = len;
362
363 /*
364 * UDC layer requires to provide a buffer even for ZLP, but should
365 * not use it at all. Let's provide some poisoned pointer to catch
366 * possible bug in the driver.
367 */
368 if (req->buf == NULL)
369 req->buf = (void *)0xDEADBABE;
370
371 INIT_COMPLETION(ffs->ep0req_completion);
372
373 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
374 if (unlikely(ret < 0))
375 return ret;
376
377 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
378 if (unlikely(ret)) {
379 usb_ep_dequeue(ffs->gadget->ep0, req);
380 return -EINTR;
381 }
382
383 ffs->setup_state = FFS_NO_SETUP;
384 return ffs->ep0req_status;
385 }
386
387 static int __ffs_ep0_stall(struct ffs_data *ffs)
388 {
389 if (ffs->ev.can_stall) {
390 pr_vdebug("ep0 stall\n");
391 usb_ep_set_halt(ffs->gadget->ep0);
392 ffs->setup_state = FFS_NO_SETUP;
393 return -EL2HLT;
394 } else {
395 pr_debug("bogus ep0 stall!\n");
396 return -ESRCH;
397 }
398 }
399
400 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
401 size_t len, loff_t *ptr)
402 {
403 struct ffs_data *ffs = file->private_data;
404 ssize_t ret;
405 char *data;
406
407 ENTER();
408
409 /* Fast check if setup was canceled */
410 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
411 return -EIDRM;
412
413 /* Acquire mutex */
414 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
415 if (unlikely(ret < 0))
416 return ret;
417
418 /* Check state */
419 switch (ffs->state) {
420 case FFS_READ_DESCRIPTORS:
421 case FFS_READ_STRINGS:
422 /* Copy data */
423 if (unlikely(len < 16)) {
424 ret = -EINVAL;
425 break;
426 }
427
428 data = ffs_prepare_buffer(buf, len);
429 if (IS_ERR(data)) {
430 ret = PTR_ERR(data);
431 break;
432 }
433
434 /* Handle data */
435 if (ffs->state == FFS_READ_DESCRIPTORS) {
436 pr_info("read descriptors\n");
437 ret = __ffs_data_got_descs(ffs, data, len);
438 if (unlikely(ret < 0))
439 break;
440
441 ffs->state = FFS_READ_STRINGS;
442 ret = len;
443 } else {
444 pr_info("read strings\n");
445 ret = __ffs_data_got_strings(ffs, data, len);
446 if (unlikely(ret < 0))
447 break;
448
449 ret = ffs_epfiles_create(ffs);
450 if (unlikely(ret)) {
451 ffs->state = FFS_CLOSING;
452 break;
453 }
454
455 ffs->state = FFS_ACTIVE;
456 mutex_unlock(&ffs->mutex);
457
458 ret = functionfs_ready_callback(ffs);
459 if (unlikely(ret < 0)) {
460 ffs->state = FFS_CLOSING;
461 return ret;
462 }
463
464 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
465 return len;
466 }
467 break;
468
469 case FFS_ACTIVE:
470 data = NULL;
471 /*
472 * We're called from user space, we can use _irq
473 * rather then _irqsave
474 */
475 spin_lock_irq(&ffs->ev.waitq.lock);
476 switch (FFS_SETUP_STATE(ffs)) {
477 case FFS_SETUP_CANCELED:
478 ret = -EIDRM;
479 goto done_spin;
480
481 case FFS_NO_SETUP:
482 ret = -ESRCH;
483 goto done_spin;
484
485 case FFS_SETUP_PENDING:
486 break;
487 }
488
489 /* FFS_SETUP_PENDING */
490 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
491 spin_unlock_irq(&ffs->ev.waitq.lock);
492 ret = __ffs_ep0_stall(ffs);
493 break;
494 }
495
496 /* FFS_SETUP_PENDING and not stall */
497 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
498
499 spin_unlock_irq(&ffs->ev.waitq.lock);
500
501 data = ffs_prepare_buffer(buf, len);
502 if (IS_ERR(data)) {
503 ret = PTR_ERR(data);
504 break;
505 }
506
507 spin_lock_irq(&ffs->ev.waitq.lock);
508
509 /*
510 * We are guaranteed to be still in FFS_ACTIVE state
511 * but the state of setup could have changed from
512 * FFS_SETUP_PENDING to FFS_SETUP_CANCELED so we need
513 * to check for that. If that happened we copied data
514 * from user space in vain but it's unlikely.
515 *
516 * For sure we are not in FFS_NO_SETUP since this is
517 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
518 * transition can be performed and it's protected by
519 * mutex.
520 */
521 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
522 ret = -EIDRM;
523 done_spin:
524 spin_unlock_irq(&ffs->ev.waitq.lock);
525 } else {
526 /* unlocks spinlock */
527 ret = __ffs_ep0_queue_wait(ffs, data, len);
528 }
529 kfree(data);
530 break;
531
532 default:
533 ret = -EBADFD;
534 break;
535 }
536
537 mutex_unlock(&ffs->mutex);
538 return ret;
539 }
540
541 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
542 size_t n)
543 {
544 /*
545 * We are holding ffs->ev.waitq.lock and ffs->mutex and we need
546 * to release them.
547 */
548 struct usb_functionfs_event events[n];
549 unsigned i = 0;
550
551 memset(events, 0, sizeof events);
552
553 do {
554 events[i].type = ffs->ev.types[i];
555 if (events[i].type == FUNCTIONFS_SETUP) {
556 events[i].u.setup = ffs->ev.setup;
557 ffs->setup_state = FFS_SETUP_PENDING;
558 }
559 } while (++i < n);
560
561 if (n < ffs->ev.count) {
562 ffs->ev.count -= n;
563 memmove(ffs->ev.types, ffs->ev.types + n,
564 ffs->ev.count * sizeof *ffs->ev.types);
565 } else {
566 ffs->ev.count = 0;
567 }
568
569 spin_unlock_irq(&ffs->ev.waitq.lock);
570 mutex_unlock(&ffs->mutex);
571
572 return unlikely(__copy_to_user(buf, events, sizeof events))
573 ? -EFAULT : sizeof events;
574 }
575
576 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
577 size_t len, loff_t *ptr)
578 {
579 struct ffs_data *ffs = file->private_data;
580 char *data = NULL;
581 size_t n;
582 int ret;
583
584 ENTER();
585
586 /* Fast check if setup was canceled */
587 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
588 return -EIDRM;
589
590 /* Acquire mutex */
591 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
592 if (unlikely(ret < 0))
593 return ret;
594
595 /* Check state */
596 if (ffs->state != FFS_ACTIVE) {
597 ret = -EBADFD;
598 goto done_mutex;
599 }
600
601 /*
602 * We're called from user space, we can use _irq rather then
603 * _irqsave
604 */
605 spin_lock_irq(&ffs->ev.waitq.lock);
606
607 switch (FFS_SETUP_STATE(ffs)) {
608 case FFS_SETUP_CANCELED:
609 ret = -EIDRM;
610 break;
611
612 case FFS_NO_SETUP:
613 n = len / sizeof(struct usb_functionfs_event);
614 if (unlikely(!n)) {
615 ret = -EINVAL;
616 break;
617 }
618
619 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
620 ret = -EAGAIN;
621 break;
622 }
623
624 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
625 ffs->ev.count)) {
626 ret = -EINTR;
627 break;
628 }
629
630 return __ffs_ep0_read_events(ffs, buf,
631 min(n, (size_t)ffs->ev.count));
632
633 case FFS_SETUP_PENDING:
634 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
635 spin_unlock_irq(&ffs->ev.waitq.lock);
636 ret = __ffs_ep0_stall(ffs);
637 goto done_mutex;
638 }
639
640 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
641
642 spin_unlock_irq(&ffs->ev.waitq.lock);
643
644 if (likely(len)) {
645 data = kmalloc(len, GFP_KERNEL);
646 if (unlikely(!data)) {
647 ret = -ENOMEM;
648 goto done_mutex;
649 }
650 }
651
652 spin_lock_irq(&ffs->ev.waitq.lock);
653
654 /* See ffs_ep0_write() */
655 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
656 ret = -EIDRM;
657 break;
658 }
659
660 /* unlocks spinlock */
661 ret = __ffs_ep0_queue_wait(ffs, data, len);
662 if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
663 ret = -EFAULT;
664 goto done_mutex;
665
666 default:
667 ret = -EBADFD;
668 break;
669 }
670
671 spin_unlock_irq(&ffs->ev.waitq.lock);
672 done_mutex:
673 mutex_unlock(&ffs->mutex);
674 kfree(data);
675 return ret;
676 }
677
678 static int ffs_ep0_open(struct inode *inode, struct file *file)
679 {
680 struct ffs_data *ffs = inode->i_private;
681
682 ENTER();
683
684 if (unlikely(ffs->state == FFS_CLOSING))
685 return -EBUSY;
686
687 file->private_data = ffs;
688 ffs_data_opened(ffs);
689
690 return 0;
691 }
692
693 static int ffs_ep0_release(struct inode *inode, struct file *file)
694 {
695 struct ffs_data *ffs = file->private_data;
696
697 ENTER();
698
699 ffs_data_closed(ffs);
700
701 return 0;
702 }
703
704 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
705 {
706 struct ffs_data *ffs = file->private_data;
707 struct usb_gadget *gadget = ffs->gadget;
708 long ret;
709
710 ENTER();
711
712 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
713 struct ffs_function *func = ffs->func;
714 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
715 } else if (gadget->ops->ioctl) {
716 ret = gadget->ops->ioctl(gadget, code, value);
717 } else {
718 ret = -ENOTTY;
719 }
720
721 return ret;
722 }
723
724 static const struct file_operations ffs_ep0_operations = {
725 .owner = THIS_MODULE,
726 .llseek = no_llseek,
727
728 .open = ffs_ep0_open,
729 .write = ffs_ep0_write,
730 .read = ffs_ep0_read,
731 .release = ffs_ep0_release,
732 .unlocked_ioctl = ffs_ep0_ioctl,
733 };
734
735
736 /* "Normal" endpoints operations ********************************************/
737
738 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
739 {
740 ENTER();
741 if (likely(req->context)) {
742 struct ffs_ep *ep = _ep->driver_data;
743 ep->status = req->status ? req->status : req->actual;
744 complete(req->context);
745 }
746 }
747
748 static ssize_t ffs_epfile_io(struct file *file,
749 char __user *buf, size_t len, int read)
750 {
751 struct ffs_epfile *epfile = file->private_data;
752 struct ffs_ep *ep;
753 char *data = NULL;
754 ssize_t ret;
755 int halt;
756
757 goto first_try;
758 do {
759 spin_unlock_irq(&epfile->ffs->eps_lock);
760 mutex_unlock(&epfile->mutex);
761
762 first_try:
763 /* Are we still active? */
764 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
765 ret = -ENODEV;
766 goto error;
767 }
768
769 /* Wait for endpoint to be enabled */
770 ep = epfile->ep;
771 if (!ep) {
772 if (file->f_flags & O_NONBLOCK) {
773 ret = -EAGAIN;
774 goto error;
775 }
776
777 if (wait_event_interruptible(epfile->wait,
778 (ep = epfile->ep))) {
779 ret = -EINTR;
780 goto error;
781 }
782 }
783
784 /* Do we halt? */
785 halt = !read == !epfile->in;
786 if (halt && epfile->isoc) {
787 ret = -EINVAL;
788 goto error;
789 }
790
791 /* Allocate & copy */
792 if (!halt && !data) {
793 data = kzalloc(len, GFP_KERNEL);
794 if (unlikely(!data))
795 return -ENOMEM;
796
797 if (!read &&
798 unlikely(__copy_from_user(data, buf, len))) {
799 ret = -EFAULT;
800 goto error;
801 }
802 }
803
804 /* We will be using request */
805 ret = ffs_mutex_lock(&epfile->mutex,
806 file->f_flags & O_NONBLOCK);
807 if (unlikely(ret))
808 goto error;
809
810 /*
811 * We're called from user space, we can use _irq rather then
812 * _irqsave
813 */
814 spin_lock_irq(&epfile->ffs->eps_lock);
815
816 /*
817 * While we were acquiring mutex endpoint got disabled
818 * or changed?
819 */
820 } while (unlikely(epfile->ep != ep));
821
822 /* Halt */
823 if (unlikely(halt)) {
824 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
825 usb_ep_set_halt(ep->ep);
826 spin_unlock_irq(&epfile->ffs->eps_lock);
827 ret = -EBADMSG;
828 } else {
829 /* Fire the request */
830 DECLARE_COMPLETION_ONSTACK(done);
831
832 struct usb_request *req = ep->req;
833 req->context = &done;
834 req->complete = ffs_epfile_io_complete;
835 req->buf = data;
836 req->length = len;
837
838 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
839
840 spin_unlock_irq(&epfile->ffs->eps_lock);
841
842 if (unlikely(ret < 0)) {
843 /* nop */
844 } else if (unlikely(wait_for_completion_interruptible(&done))) {
845 ret = -EINTR;
846 usb_ep_dequeue(ep->ep, req);
847 } else {
848 ret = ep->status;
849 if (read && ret > 0 &&
850 unlikely(copy_to_user(buf, data, ret)))
851 ret = -EFAULT;
852 }
853 }
854
855 mutex_unlock(&epfile->mutex);
856 error:
857 kfree(data);
858 return ret;
859 }
860
861 static ssize_t
862 ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
863 loff_t *ptr)
864 {
865 ENTER();
866
867 return ffs_epfile_io(file, (char __user *)buf, len, 0);
868 }
869
870 static ssize_t
871 ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
872 {
873 ENTER();
874
875 return ffs_epfile_io(file, buf, len, 1);
876 }
877
878 static int
879 ffs_epfile_open(struct inode *inode, struct file *file)
880 {
881 struct ffs_epfile *epfile = inode->i_private;
882
883 ENTER();
884
885 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
886 return -ENODEV;
887
888 file->private_data = epfile;
889 ffs_data_opened(epfile->ffs);
890
891 return 0;
892 }
893
894 static int
895 ffs_epfile_release(struct inode *inode, struct file *file)
896 {
897 struct ffs_epfile *epfile = inode->i_private;
898
899 ENTER();
900
901 ffs_data_closed(epfile->ffs);
902
903 return 0;
904 }
905
906 static long ffs_epfile_ioctl(struct file *file, unsigned code,
907 unsigned long value)
908 {
909 struct ffs_epfile *epfile = file->private_data;
910 int ret;
911
912 ENTER();
913
914 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
915 return -ENODEV;
916
917 spin_lock_irq(&epfile->ffs->eps_lock);
918 if (likely(epfile->ep)) {
919 switch (code) {
920 case FUNCTIONFS_FIFO_STATUS:
921 ret = usb_ep_fifo_status(epfile->ep->ep);
922 break;
923 case FUNCTIONFS_FIFO_FLUSH:
924 usb_ep_fifo_flush(epfile->ep->ep);
925 ret = 0;
926 break;
927 case FUNCTIONFS_CLEAR_HALT:
928 ret = usb_ep_clear_halt(epfile->ep->ep);
929 break;
930 case FUNCTIONFS_ENDPOINT_REVMAP:
931 ret = epfile->ep->num;
932 break;
933 default:
934 ret = -ENOTTY;
935 }
936 } else {
937 ret = -ENODEV;
938 }
939 spin_unlock_irq(&epfile->ffs->eps_lock);
940
941 return ret;
942 }
943
944 static const struct file_operations ffs_epfile_operations = {
945 .owner = THIS_MODULE,
946 .llseek = no_llseek,
947
948 .open = ffs_epfile_open,
949 .write = ffs_epfile_write,
950 .read = ffs_epfile_read,
951 .release = ffs_epfile_release,
952 .unlocked_ioctl = ffs_epfile_ioctl,
953 };
954
955
956 /* File system and super block operations ***********************************/
957
958 /*
959 * Mounting the file system creates a controller file, used first for
960 * function configuration then later for event monitoring.
961 */
962
963 static struct inode *__must_check
964 ffs_sb_make_inode(struct super_block *sb, void *data,
965 const struct file_operations *fops,
966 const struct inode_operations *iops,
967 struct ffs_file_perms *perms)
968 {
969 struct inode *inode;
970
971 ENTER();
972
973 inode = new_inode(sb);
974
975 if (likely(inode)) {
976 struct timespec current_time = CURRENT_TIME;
977
978 inode->i_ino = get_next_ino();
979 inode->i_mode = perms->mode;
980 inode->i_uid = perms->uid;
981 inode->i_gid = perms->gid;
982 inode->i_atime = current_time;
983 inode->i_mtime = current_time;
984 inode->i_ctime = current_time;
985 inode->i_private = data;
986 if (fops)
987 inode->i_fop = fops;
988 if (iops)
989 inode->i_op = iops;
990 }
991
992 return inode;
993 }
994
995 /* Create "regular" file */
996 static struct inode *ffs_sb_create_file(struct super_block *sb,
997 const char *name, void *data,
998 const struct file_operations *fops,
999 struct dentry **dentry_p)
1000 {
1001 struct ffs_data *ffs = sb->s_fs_info;
1002 struct dentry *dentry;
1003 struct inode *inode;
1004
1005 ENTER();
1006
1007 dentry = d_alloc_name(sb->s_root, name);
1008 if (unlikely(!dentry))
1009 return NULL;
1010
1011 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1012 if (unlikely(!inode)) {
1013 dput(dentry);
1014 return NULL;
1015 }
1016
1017 d_add(dentry, inode);
1018 if (dentry_p)
1019 *dentry_p = dentry;
1020
1021 return inode;
1022 }
1023
1024 /* Super block */
1025 static const struct super_operations ffs_sb_operations = {
1026 .statfs = simple_statfs,
1027 .drop_inode = generic_delete_inode,
1028 };
1029
1030 struct ffs_sb_fill_data {
1031 struct ffs_file_perms perms;
1032 umode_t root_mode;
1033 const char *dev_name;
1034 };
1035
1036 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1037 {
1038 struct ffs_sb_fill_data *data = _data;
1039 struct inode *inode;
1040 struct ffs_data *ffs;
1041
1042 ENTER();
1043
1044 /* Initialise data */
1045 ffs = ffs_data_new();
1046 if (unlikely(!ffs))
1047 goto Enomem;
1048
1049 ffs->sb = sb;
1050 ffs->dev_name = data->dev_name;
1051 ffs->file_perms = data->perms;
1052
1053 sb->s_fs_info = ffs;
1054 sb->s_blocksize = PAGE_CACHE_SIZE;
1055 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1056 sb->s_magic = FUNCTIONFS_MAGIC;
1057 sb->s_op = &ffs_sb_operations;
1058 sb->s_time_gran = 1;
1059
1060 /* Root inode */
1061 data->perms.mode = data->root_mode;
1062 inode = ffs_sb_make_inode(sb, NULL,
1063 &simple_dir_operations,
1064 &simple_dir_inode_operations,
1065 &data->perms);
1066 if (unlikely(!inode))
1067 goto Enomem;
1068 sb->s_root = d_alloc_root(inode);
1069 if (unlikely(!sb->s_root)) {
1070 iput(inode);
1071 goto Enomem;
1072 }
1073
1074 /* EP0 file */
1075 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1076 &ffs_ep0_operations, NULL)))
1077 goto Enomem;
1078
1079 return 0;
1080
1081 Enomem:
1082 return -ENOMEM;
1083 }
1084
1085 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1086 {
1087 ENTER();
1088
1089 if (!opts || !*opts)
1090 return 0;
1091
1092 for (;;) {
1093 char *end, *eq, *comma;
1094 unsigned long value;
1095
1096 /* Option limit */
1097 comma = strchr(opts, ',');
1098 if (comma)
1099 *comma = 0;
1100
1101 /* Value limit */
1102 eq = strchr(opts, '=');
1103 if (unlikely(!eq)) {
1104 pr_err("'=' missing in %s\n", opts);
1105 return -EINVAL;
1106 }
1107 *eq = 0;
1108
1109 /* Parse value */
1110 value = simple_strtoul(eq + 1, &end, 0);
1111 if (unlikely(*end != ',' && *end != 0)) {
1112 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1113 return -EINVAL;
1114 }
1115
1116 /* Interpret option */
1117 switch (eq - opts) {
1118 case 5:
1119 if (!memcmp(opts, "rmode", 5))
1120 data->root_mode = (value & 0555) | S_IFDIR;
1121 else if (!memcmp(opts, "fmode", 5))
1122 data->perms.mode = (value & 0666) | S_IFREG;
1123 else
1124 goto invalid;
1125 break;
1126
1127 case 4:
1128 if (!memcmp(opts, "mode", 4)) {
1129 data->root_mode = (value & 0555) | S_IFDIR;
1130 data->perms.mode = (value & 0666) | S_IFREG;
1131 } else {
1132 goto invalid;
1133 }
1134 break;
1135
1136 case 3:
1137 if (!memcmp(opts, "uid", 3))
1138 data->perms.uid = value;
1139 else if (!memcmp(opts, "gid", 3))
1140 data->perms.gid = value;
1141 else
1142 goto invalid;
1143 break;
1144
1145 default:
1146 invalid:
1147 pr_err("%s: invalid option\n", opts);
1148 return -EINVAL;
1149 }
1150
1151 /* Next iteration */
1152 if (!comma)
1153 break;
1154 opts = comma + 1;
1155 }
1156
1157 return 0;
1158 }
1159
1160 /* "mount -t functionfs dev_name /dev/function" ends up here */
1161
1162 static struct dentry *
1163 ffs_fs_mount(struct file_system_type *t, int flags,
1164 const char *dev_name, void *opts)
1165 {
1166 struct ffs_sb_fill_data data = {
1167 .perms = {
1168 .mode = S_IFREG | 0600,
1169 .uid = 0,
1170 .gid = 0
1171 },
1172 .root_mode = S_IFDIR | 0500,
1173 };
1174 int ret;
1175
1176 ENTER();
1177
1178 ret = functionfs_check_dev_callback(dev_name);
1179 if (unlikely(ret < 0))
1180 return ERR_PTR(ret);
1181
1182 ret = ffs_fs_parse_opts(&data, opts);
1183 if (unlikely(ret < 0))
1184 return ERR_PTR(ret);
1185
1186 data.dev_name = dev_name;
1187 return mount_single(t, flags, &data, ffs_sb_fill);
1188 }
1189
1190 static void
1191 ffs_fs_kill_sb(struct super_block *sb)
1192 {
1193 ENTER();
1194
1195 kill_litter_super(sb);
1196 if (sb->s_fs_info)
1197 ffs_data_put(sb->s_fs_info);
1198 }
1199
1200 static struct file_system_type ffs_fs_type = {
1201 .owner = THIS_MODULE,
1202 .name = "functionfs",
1203 .mount = ffs_fs_mount,
1204 .kill_sb = ffs_fs_kill_sb,
1205 };
1206
1207
1208 /* Driver's main init/cleanup functions *************************************/
1209
1210 static int functionfs_init(void)
1211 {
1212 int ret;
1213
1214 ENTER();
1215
1216 ret = register_filesystem(&ffs_fs_type);
1217 if (likely(!ret))
1218 pr_info("file system registered\n");
1219 else
1220 pr_err("failed registering file system (%d)\n", ret);
1221
1222 return ret;
1223 }
1224
1225 static void functionfs_cleanup(void)
1226 {
1227 ENTER();
1228
1229 pr_info("unloading\n");
1230 unregister_filesystem(&ffs_fs_type);
1231 }
1232
1233
1234 /* ffs_data and ffs_function construction and destruction code **************/
1235
1236 static void ffs_data_clear(struct ffs_data *ffs);
1237 static void ffs_data_reset(struct ffs_data *ffs);
1238
1239 static void ffs_data_get(struct ffs_data *ffs)
1240 {
1241 ENTER();
1242
1243 atomic_inc(&ffs->ref);
1244 }
1245
1246 static void ffs_data_opened(struct ffs_data *ffs)
1247 {
1248 ENTER();
1249
1250 atomic_inc(&ffs->ref);
1251 atomic_inc(&ffs->opened);
1252 }
1253
1254 static void ffs_data_put(struct ffs_data *ffs)
1255 {
1256 ENTER();
1257
1258 if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1259 pr_info("%s(): freeing\n", __func__);
1260 ffs_data_clear(ffs);
1261 BUG_ON(mutex_is_locked(&ffs->mutex) ||
1262 spin_is_locked(&ffs->ev.waitq.lock) ||
1263 waitqueue_active(&ffs->ev.waitq) ||
1264 waitqueue_active(&ffs->ep0req_completion.wait));
1265 kfree(ffs);
1266 }
1267 }
1268
1269 static void ffs_data_closed(struct ffs_data *ffs)
1270 {
1271 ENTER();
1272
1273 if (atomic_dec_and_test(&ffs->opened)) {
1274 ffs->state = FFS_CLOSING;
1275 ffs_data_reset(ffs);
1276 }
1277
1278 ffs_data_put(ffs);
1279 }
1280
1281 static struct ffs_data *ffs_data_new(void)
1282 {
1283 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1284 if (unlikely(!ffs))
1285 return 0;
1286
1287 ENTER();
1288
1289 atomic_set(&ffs->ref, 1);
1290 atomic_set(&ffs->opened, 0);
1291 ffs->state = FFS_READ_DESCRIPTORS;
1292 mutex_init(&ffs->mutex);
1293 spin_lock_init(&ffs->eps_lock);
1294 init_waitqueue_head(&ffs->ev.waitq);
1295 init_completion(&ffs->ep0req_completion);
1296
1297 /* XXX REVISIT need to update it in some places, or do we? */
1298 ffs->ev.can_stall = 1;
1299
1300 return ffs;
1301 }
1302
1303 static void ffs_data_clear(struct ffs_data *ffs)
1304 {
1305 ENTER();
1306
1307 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1308 functionfs_closed_callback(ffs);
1309
1310 BUG_ON(ffs->gadget);
1311
1312 if (ffs->epfiles)
1313 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1314
1315 kfree(ffs->raw_descs);
1316 kfree(ffs->raw_strings);
1317 kfree(ffs->stringtabs);
1318 }
1319
1320 static void ffs_data_reset(struct ffs_data *ffs)
1321 {
1322 ENTER();
1323
1324 ffs_data_clear(ffs);
1325
1326 ffs->epfiles = NULL;
1327 ffs->raw_descs = NULL;
1328 ffs->raw_strings = NULL;
1329 ffs->stringtabs = NULL;
1330
1331 ffs->raw_descs_length = 0;
1332 ffs->raw_fs_descs_length = 0;
1333 ffs->fs_descs_count = 0;
1334 ffs->hs_descs_count = 0;
1335
1336 ffs->strings_count = 0;
1337 ffs->interfaces_count = 0;
1338 ffs->eps_count = 0;
1339
1340 ffs->ev.count = 0;
1341
1342 ffs->state = FFS_READ_DESCRIPTORS;
1343 ffs->setup_state = FFS_NO_SETUP;
1344 ffs->flags = 0;
1345 }
1346
1347
1348 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1349 {
1350 struct usb_gadget_strings **lang;
1351 int first_id;
1352
1353 ENTER();
1354
1355 if (WARN_ON(ffs->state != FFS_ACTIVE
1356 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1357 return -EBADFD;
1358
1359 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1360 if (unlikely(first_id < 0))
1361 return first_id;
1362
1363 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1364 if (unlikely(!ffs->ep0req))
1365 return -ENOMEM;
1366 ffs->ep0req->complete = ffs_ep0_complete;
1367 ffs->ep0req->context = ffs;
1368
1369 lang = ffs->stringtabs;
1370 for (lang = ffs->stringtabs; *lang; ++lang) {
1371 struct usb_string *str = (*lang)->strings;
1372 int id = first_id;
1373 for (; str->s; ++id, ++str)
1374 str->id = id;
1375 }
1376
1377 ffs->gadget = cdev->gadget;
1378 ffs_data_get(ffs);
1379 return 0;
1380 }
1381
1382 static void functionfs_unbind(struct ffs_data *ffs)
1383 {
1384 ENTER();
1385
1386 if (!WARN_ON(!ffs->gadget)) {
1387 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1388 ffs->ep0req = NULL;
1389 ffs->gadget = NULL;
1390 ffs_data_put(ffs);
1391 }
1392 }
1393
1394 static int ffs_epfiles_create(struct ffs_data *ffs)
1395 {
1396 struct ffs_epfile *epfile, *epfiles;
1397 unsigned i, count;
1398
1399 ENTER();
1400
1401 count = ffs->eps_count;
1402 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1403 if (!epfiles)
1404 return -ENOMEM;
1405
1406 epfile = epfiles;
1407 for (i = 1; i <= count; ++i, ++epfile) {
1408 epfile->ffs = ffs;
1409 mutex_init(&epfile->mutex);
1410 init_waitqueue_head(&epfile->wait);
1411 sprintf(epfiles->name, "ep%u", i);
1412 if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
1413 &ffs_epfile_operations,
1414 &epfile->dentry))) {
1415 ffs_epfiles_destroy(epfiles, i - 1);
1416 return -ENOMEM;
1417 }
1418 }
1419
1420 ffs->epfiles = epfiles;
1421 return 0;
1422 }
1423
1424 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1425 {
1426 struct ffs_epfile *epfile = epfiles;
1427
1428 ENTER();
1429
1430 for (; count; --count, ++epfile) {
1431 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1432 waitqueue_active(&epfile->wait));
1433 if (epfile->dentry) {
1434 d_delete(epfile->dentry);
1435 dput(epfile->dentry);
1436 epfile->dentry = NULL;
1437 }
1438 }
1439
1440 kfree(epfiles);
1441 }
1442
1443 static int functionfs_bind_config(struct usb_composite_dev *cdev,
1444 struct usb_configuration *c,
1445 struct ffs_data *ffs)
1446 {
1447 struct ffs_function *func;
1448 int ret;
1449
1450 ENTER();
1451
1452 func = kzalloc(sizeof *func, GFP_KERNEL);
1453 if (unlikely(!func))
1454 return -ENOMEM;
1455
1456 func->function.name = "Function FS Gadget";
1457 func->function.strings = ffs->stringtabs;
1458
1459 func->function.bind = ffs_func_bind;
1460 func->function.unbind = ffs_func_unbind;
1461 func->function.set_alt = ffs_func_set_alt;
1462 func->function.disable = ffs_func_disable;
1463 func->function.setup = ffs_func_setup;
1464 func->function.suspend = ffs_func_suspend;
1465 func->function.resume = ffs_func_resume;
1466
1467 func->conf = c;
1468 func->gadget = cdev->gadget;
1469 func->ffs = ffs;
1470 ffs_data_get(ffs);
1471
1472 ret = usb_add_function(c, &func->function);
1473 if (unlikely(ret))
1474 ffs_func_free(func);
1475
1476 return ret;
1477 }
1478
1479 static void ffs_func_free(struct ffs_function *func)
1480 {
1481 ENTER();
1482
1483 ffs_data_put(func->ffs);
1484
1485 kfree(func->eps);
1486 /*
1487 * eps and interfaces_nums are allocated in the same chunk so
1488 * only one free is required. Descriptors are also allocated
1489 * in the same chunk.
1490 */
1491
1492 kfree(func);
1493 }
1494
1495 static void ffs_func_eps_disable(struct ffs_function *func)
1496 {
1497 struct ffs_ep *ep = func->eps;
1498 struct ffs_epfile *epfile = func->ffs->epfiles;
1499 unsigned count = func->ffs->eps_count;
1500 unsigned long flags;
1501
1502 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1503 do {
1504 /* pending requests get nuked */
1505 if (likely(ep->ep))
1506 usb_ep_disable(ep->ep);
1507 epfile->ep = NULL;
1508
1509 ++ep;
1510 ++epfile;
1511 } while (--count);
1512 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1513 }
1514
1515 static int ffs_func_eps_enable(struct ffs_function *func)
1516 {
1517 struct ffs_data *ffs = func->ffs;
1518 struct ffs_ep *ep = func->eps;
1519 struct ffs_epfile *epfile = ffs->epfiles;
1520 unsigned count = ffs->eps_count;
1521 unsigned long flags;
1522 int ret = 0;
1523
1524 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1525 do {
1526 struct usb_endpoint_descriptor *ds;
1527 ds = ep->descs[ep->descs[1] ? 1 : 0];
1528
1529 ep->ep->driver_data = ep;
1530 ep->ep->desc = ds;
1531 ret = usb_ep_enable(ep->ep);
1532 if (likely(!ret)) {
1533 epfile->ep = ep;
1534 epfile->in = usb_endpoint_dir_in(ds);
1535 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1536 } else {
1537 break;
1538 }
1539
1540 wake_up(&epfile->wait);
1541
1542 ++ep;
1543 ++epfile;
1544 } while (--count);
1545 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1546
1547 return ret;
1548 }
1549
1550
1551 /* Parsing and building descriptors and strings *****************************/
1552
1553 /*
1554 * This validates if data pointed by data is a valid USB descriptor as
1555 * well as record how many interfaces, endpoints and strings are
1556 * required by given configuration. Returns address after the
1557 * descriptor or NULL if data is invalid.
1558 */
1559
1560 enum ffs_entity_type {
1561 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1562 };
1563
1564 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1565 u8 *valuep,
1566 struct usb_descriptor_header *desc,
1567 void *priv);
1568
1569 static int __must_check ffs_do_desc(char *data, unsigned len,
1570 ffs_entity_callback entity, void *priv)
1571 {
1572 struct usb_descriptor_header *_ds = (void *)data;
1573 u8 length;
1574 int ret;
1575
1576 ENTER();
1577
1578 /* At least two bytes are required: length and type */
1579 if (len < 2) {
1580 pr_vdebug("descriptor too short\n");
1581 return -EINVAL;
1582 }
1583
1584 /* If we have at least as many bytes as the descriptor takes? */
1585 length = _ds->bLength;
1586 if (len < length) {
1587 pr_vdebug("descriptor longer then available data\n");
1588 return -EINVAL;
1589 }
1590
1591 #define __entity_check_INTERFACE(val) 1
1592 #define __entity_check_STRING(val) (val)
1593 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1594 #define __entity(type, val) do { \
1595 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1596 if (unlikely(!__entity_check_ ##type(val))) { \
1597 pr_vdebug("invalid entity's value\n"); \
1598 return -EINVAL; \
1599 } \
1600 ret = entity(FFS_ ##type, &val, _ds, priv); \
1601 if (unlikely(ret < 0)) { \
1602 pr_debug("entity " #type "(%02x); ret = %d\n", \
1603 (val), ret); \
1604 return ret; \
1605 } \
1606 } while (0)
1607
1608 /* Parse descriptor depending on type. */
1609 switch (_ds->bDescriptorType) {
1610 case USB_DT_DEVICE:
1611 case USB_DT_CONFIG:
1612 case USB_DT_STRING:
1613 case USB_DT_DEVICE_QUALIFIER:
1614 /* function can't have any of those */
1615 pr_vdebug("descriptor reserved for gadget: %d\n",
1616 _ds->bDescriptorType);
1617 return -EINVAL;
1618
1619 case USB_DT_INTERFACE: {
1620 struct usb_interface_descriptor *ds = (void *)_ds;
1621 pr_vdebug("interface descriptor\n");
1622 if (length != sizeof *ds)
1623 goto inv_length;
1624
1625 __entity(INTERFACE, ds->bInterfaceNumber);
1626 if (ds->iInterface)
1627 __entity(STRING, ds->iInterface);
1628 }
1629 break;
1630
1631 case USB_DT_ENDPOINT: {
1632 struct usb_endpoint_descriptor *ds = (void *)_ds;
1633 pr_vdebug("endpoint descriptor\n");
1634 if (length != USB_DT_ENDPOINT_SIZE &&
1635 length != USB_DT_ENDPOINT_AUDIO_SIZE)
1636 goto inv_length;
1637 __entity(ENDPOINT, ds->bEndpointAddress);
1638 }
1639 break;
1640
1641 case USB_DT_OTG:
1642 if (length != sizeof(struct usb_otg_descriptor))
1643 goto inv_length;
1644 break;
1645
1646 case USB_DT_INTERFACE_ASSOCIATION: {
1647 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1648 pr_vdebug("interface association descriptor\n");
1649 if (length != sizeof *ds)
1650 goto inv_length;
1651 if (ds->iFunction)
1652 __entity(STRING, ds->iFunction);
1653 }
1654 break;
1655
1656 case USB_DT_OTHER_SPEED_CONFIG:
1657 case USB_DT_INTERFACE_POWER:
1658 case USB_DT_DEBUG:
1659 case USB_DT_SECURITY:
1660 case USB_DT_CS_RADIO_CONTROL:
1661 /* TODO */
1662 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1663 return -EINVAL;
1664
1665 default:
1666 /* We should never be here */
1667 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1668 return -EINVAL;
1669
1670 inv_length:
1671 pr_vdebug("invalid length: %d (descriptor %d)\n",
1672 _ds->bLength, _ds->bDescriptorType);
1673 return -EINVAL;
1674 }
1675
1676 #undef __entity
1677 #undef __entity_check_DESCRIPTOR
1678 #undef __entity_check_INTERFACE
1679 #undef __entity_check_STRING
1680 #undef __entity_check_ENDPOINT
1681
1682 return length;
1683 }
1684
1685 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1686 ffs_entity_callback entity, void *priv)
1687 {
1688 const unsigned _len = len;
1689 unsigned long num = 0;
1690
1691 ENTER();
1692
1693 for (;;) {
1694 int ret;
1695
1696 if (num == count)
1697 data = NULL;
1698
1699 /* Record "descriptor" entity */
1700 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1701 if (unlikely(ret < 0)) {
1702 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1703 num, ret);
1704 return ret;
1705 }
1706
1707 if (!data)
1708 return _len - len;
1709
1710 ret = ffs_do_desc(data, len, entity, priv);
1711 if (unlikely(ret < 0)) {
1712 pr_debug("%s returns %d\n", __func__, ret);
1713 return ret;
1714 }
1715
1716 len -= ret;
1717 data += ret;
1718 ++num;
1719 }
1720 }
1721
1722 static int __ffs_data_do_entity(enum ffs_entity_type type,
1723 u8 *valuep, struct usb_descriptor_header *desc,
1724 void *priv)
1725 {
1726 struct ffs_data *ffs = priv;
1727
1728 ENTER();
1729
1730 switch (type) {
1731 case FFS_DESCRIPTOR:
1732 break;
1733
1734 case FFS_INTERFACE:
1735 /*
1736 * Interfaces are indexed from zero so if we
1737 * encountered interface "n" then there are at least
1738 * "n+1" interfaces.
1739 */
1740 if (*valuep >= ffs->interfaces_count)
1741 ffs->interfaces_count = *valuep + 1;
1742 break;
1743
1744 case FFS_STRING:
1745 /*
1746 * Strings are indexed from 1 (0 is magic ;) reserved
1747 * for languages list or some such)
1748 */
1749 if (*valuep > ffs->strings_count)
1750 ffs->strings_count = *valuep;
1751 break;
1752
1753 case FFS_ENDPOINT:
1754 /* Endpoints are indexed from 1 as well. */
1755 if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
1756 ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
1757 break;
1758 }
1759
1760 return 0;
1761 }
1762
1763 static int __ffs_data_got_descs(struct ffs_data *ffs,
1764 char *const _data, size_t len)
1765 {
1766 unsigned fs_count, hs_count;
1767 int fs_len, ret = -EINVAL;
1768 char *data = _data;
1769
1770 ENTER();
1771
1772 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
1773 get_unaligned_le32(data + 4) != len))
1774 goto error;
1775 fs_count = get_unaligned_le32(data + 8);
1776 hs_count = get_unaligned_le32(data + 12);
1777
1778 if (!fs_count && !hs_count)
1779 goto einval;
1780
1781 data += 16;
1782 len -= 16;
1783
1784 if (likely(fs_count)) {
1785 fs_len = ffs_do_descs(fs_count, data, len,
1786 __ffs_data_do_entity, ffs);
1787 if (unlikely(fs_len < 0)) {
1788 ret = fs_len;
1789 goto error;
1790 }
1791
1792 data += fs_len;
1793 len -= fs_len;
1794 } else {
1795 fs_len = 0;
1796 }
1797
1798 if (likely(hs_count)) {
1799 ret = ffs_do_descs(hs_count, data, len,
1800 __ffs_data_do_entity, ffs);
1801 if (unlikely(ret < 0))
1802 goto error;
1803 } else {
1804 ret = 0;
1805 }
1806
1807 if (unlikely(len != ret))
1808 goto einval;
1809
1810 ffs->raw_fs_descs_length = fs_len;
1811 ffs->raw_descs_length = fs_len + ret;
1812 ffs->raw_descs = _data;
1813 ffs->fs_descs_count = fs_count;
1814 ffs->hs_descs_count = hs_count;
1815
1816 return 0;
1817
1818 einval:
1819 ret = -EINVAL;
1820 error:
1821 kfree(_data);
1822 return ret;
1823 }
1824
1825 static int __ffs_data_got_strings(struct ffs_data *ffs,
1826 char *const _data, size_t len)
1827 {
1828 u32 str_count, needed_count, lang_count;
1829 struct usb_gadget_strings **stringtabs, *t;
1830 struct usb_string *strings, *s;
1831 const char *data = _data;
1832
1833 ENTER();
1834
1835 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
1836 get_unaligned_le32(data + 4) != len))
1837 goto error;
1838 str_count = get_unaligned_le32(data + 8);
1839 lang_count = get_unaligned_le32(data + 12);
1840
1841 /* if one is zero the other must be zero */
1842 if (unlikely(!str_count != !lang_count))
1843 goto error;
1844
1845 /* Do we have at least as many strings as descriptors need? */
1846 needed_count = ffs->strings_count;
1847 if (unlikely(str_count < needed_count))
1848 goto error;
1849
1850 /*
1851 * If we don't need any strings just return and free all
1852 * memory.
1853 */
1854 if (!needed_count) {
1855 kfree(_data);
1856 return 0;
1857 }
1858
1859 /* Allocate everything in one chunk so there's less maintenance. */
1860 {
1861 struct {
1862 struct usb_gadget_strings *stringtabs[lang_count + 1];
1863 struct usb_gadget_strings stringtab[lang_count];
1864 struct usb_string strings[lang_count*(needed_count+1)];
1865 } *d;
1866 unsigned i = 0;
1867
1868 d = kmalloc(sizeof *d, GFP_KERNEL);
1869 if (unlikely(!d)) {
1870 kfree(_data);
1871 return -ENOMEM;
1872 }
1873
1874 stringtabs = d->stringtabs;
1875 t = d->stringtab;
1876 i = lang_count;
1877 do {
1878 *stringtabs++ = t++;
1879 } while (--i);
1880 *stringtabs = NULL;
1881
1882 stringtabs = d->stringtabs;
1883 t = d->stringtab;
1884 s = d->strings;
1885 strings = s;
1886 }
1887
1888 /* For each language */
1889 data += 16;
1890 len -= 16;
1891
1892 do { /* lang_count > 0 so we can use do-while */
1893 unsigned needed = needed_count;
1894
1895 if (unlikely(len < 3))
1896 goto error_free;
1897 t->language = get_unaligned_le16(data);
1898 t->strings = s;
1899 ++t;
1900
1901 data += 2;
1902 len -= 2;
1903
1904 /* For each string */
1905 do { /* str_count > 0 so we can use do-while */
1906 size_t length = strnlen(data, len);
1907
1908 if (unlikely(length == len))
1909 goto error_free;
1910
1911 /*
1912 * User may provide more strings then we need,
1913 * if that's the case we simply ignore the
1914 * rest
1915 */
1916 if (likely(needed)) {
1917 /*
1918 * s->id will be set while adding
1919 * function to configuration so for
1920 * now just leave garbage here.
1921 */
1922 s->s = data;
1923 --needed;
1924 ++s;
1925 }
1926
1927 data += length + 1;
1928 len -= length + 1;
1929 } while (--str_count);
1930
1931 s->id = 0; /* terminator */
1932 s->s = NULL;
1933 ++s;
1934
1935 } while (--lang_count);
1936
1937 /* Some garbage left? */
1938 if (unlikely(len))
1939 goto error_free;
1940
1941 /* Done! */
1942 ffs->stringtabs = stringtabs;
1943 ffs->raw_strings = _data;
1944
1945 return 0;
1946
1947 error_free:
1948 kfree(stringtabs);
1949 error:
1950 kfree(_data);
1951 return -EINVAL;
1952 }
1953
1954
1955 /* Events handling and management *******************************************/
1956
1957 static void __ffs_event_add(struct ffs_data *ffs,
1958 enum usb_functionfs_event_type type)
1959 {
1960 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
1961 int neg = 0;
1962
1963 /*
1964 * Abort any unhandled setup
1965 *
1966 * We do not need to worry about some cmpxchg() changing value
1967 * of ffs->setup_state without holding the lock because when
1968 * state is FFS_SETUP_PENDING cmpxchg() in several places in
1969 * the source does nothing.
1970 */
1971 if (ffs->setup_state == FFS_SETUP_PENDING)
1972 ffs->setup_state = FFS_SETUP_CANCELED;
1973
1974 switch (type) {
1975 case FUNCTIONFS_RESUME:
1976 rem_type2 = FUNCTIONFS_SUSPEND;
1977 /* FALL THROUGH */
1978 case FUNCTIONFS_SUSPEND:
1979 case FUNCTIONFS_SETUP:
1980 rem_type1 = type;
1981 /* Discard all similar events */
1982 break;
1983
1984 case FUNCTIONFS_BIND:
1985 case FUNCTIONFS_UNBIND:
1986 case FUNCTIONFS_DISABLE:
1987 case FUNCTIONFS_ENABLE:
1988 /* Discard everything other then power management. */
1989 rem_type1 = FUNCTIONFS_SUSPEND;
1990 rem_type2 = FUNCTIONFS_RESUME;
1991 neg = 1;
1992 break;
1993
1994 default:
1995 BUG();
1996 }
1997
1998 {
1999 u8 *ev = ffs->ev.types, *out = ev;
2000 unsigned n = ffs->ev.count;
2001 for (; n; --n, ++ev)
2002 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2003 *out++ = *ev;
2004 else
2005 pr_vdebug("purging event %d\n", *ev);
2006 ffs->ev.count = out - ffs->ev.types;
2007 }
2008
2009 pr_vdebug("adding event %d\n", type);
2010 ffs->ev.types[ffs->ev.count++] = type;
2011 wake_up_locked(&ffs->ev.waitq);
2012 }
2013
2014 static void ffs_event_add(struct ffs_data *ffs,
2015 enum usb_functionfs_event_type type)
2016 {
2017 unsigned long flags;
2018 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2019 __ffs_event_add(ffs, type);
2020 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2021 }
2022
2023
2024 /* Bind/unbind USB function hooks *******************************************/
2025
2026 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2027 struct usb_descriptor_header *desc,
2028 void *priv)
2029 {
2030 struct usb_endpoint_descriptor *ds = (void *)desc;
2031 struct ffs_function *func = priv;
2032 struct ffs_ep *ffs_ep;
2033
2034 /*
2035 * If hs_descriptors is not NULL then we are reading hs
2036 * descriptors now
2037 */
2038 const int isHS = func->function.hs_descriptors != NULL;
2039 unsigned idx;
2040
2041 if (type != FFS_DESCRIPTOR)
2042 return 0;
2043
2044 if (isHS)
2045 func->function.hs_descriptors[(long)valuep] = desc;
2046 else
2047 func->function.descriptors[(long)valuep] = desc;
2048
2049 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2050 return 0;
2051
2052 idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
2053 ffs_ep = func->eps + idx;
2054
2055 if (unlikely(ffs_ep->descs[isHS])) {
2056 pr_vdebug("two %sspeed descriptors for EP %d\n",
2057 isHS ? "high" : "full",
2058 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2059 return -EINVAL;
2060 }
2061 ffs_ep->descs[isHS] = ds;
2062
2063 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2064 if (ffs_ep->ep) {
2065 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2066 if (!ds->wMaxPacketSize)
2067 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2068 } else {
2069 struct usb_request *req;
2070 struct usb_ep *ep;
2071
2072 pr_vdebug("autoconfig\n");
2073 ep = usb_ep_autoconfig(func->gadget, ds);
2074 if (unlikely(!ep))
2075 return -ENOTSUPP;
2076 ep->driver_data = func->eps + idx;
2077
2078 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2079 if (unlikely(!req))
2080 return -ENOMEM;
2081
2082 ffs_ep->ep = ep;
2083 ffs_ep->req = req;
2084 func->eps_revmap[ds->bEndpointAddress &
2085 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2086 }
2087 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2088
2089 return 0;
2090 }
2091
2092 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2093 struct usb_descriptor_header *desc,
2094 void *priv)
2095 {
2096 struct ffs_function *func = priv;
2097 unsigned idx;
2098 u8 newValue;
2099
2100 switch (type) {
2101 default:
2102 case FFS_DESCRIPTOR:
2103 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2104 return 0;
2105
2106 case FFS_INTERFACE:
2107 idx = *valuep;
2108 if (func->interfaces_nums[idx] < 0) {
2109 int id = usb_interface_id(func->conf, &func->function);
2110 if (unlikely(id < 0))
2111 return id;
2112 func->interfaces_nums[idx] = id;
2113 }
2114 newValue = func->interfaces_nums[idx];
2115 break;
2116
2117 case FFS_STRING:
2118 /* String' IDs are allocated when fsf_data is bound to cdev */
2119 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2120 break;
2121
2122 case FFS_ENDPOINT:
2123 /*
2124 * USB_DT_ENDPOINT are handled in
2125 * __ffs_func_bind_do_descs().
2126 */
2127 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2128 return 0;
2129
2130 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2131 if (unlikely(!func->eps[idx].ep))
2132 return -EINVAL;
2133
2134 {
2135 struct usb_endpoint_descriptor **descs;
2136 descs = func->eps[idx].descs;
2137 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2138 }
2139 break;
2140 }
2141
2142 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2143 *valuep = newValue;
2144 return 0;
2145 }
2146
2147 static int ffs_func_bind(struct usb_configuration *c,
2148 struct usb_function *f)
2149 {
2150 struct ffs_function *func = ffs_func_from_usb(f);
2151 struct ffs_data *ffs = func->ffs;
2152
2153 const int full = !!func->ffs->fs_descs_count;
2154 const int high = gadget_is_dualspeed(func->gadget) &&
2155 func->ffs->hs_descs_count;
2156
2157 int ret;
2158
2159 /* Make it a single chunk, less management later on */
2160 struct {
2161 struct ffs_ep eps[ffs->eps_count];
2162 struct usb_descriptor_header
2163 *fs_descs[full ? ffs->fs_descs_count + 1 : 0];
2164 struct usb_descriptor_header
2165 *hs_descs[high ? ffs->hs_descs_count + 1 : 0];
2166 short inums[ffs->interfaces_count];
2167 char raw_descs[high ? ffs->raw_descs_length
2168 : ffs->raw_fs_descs_length];
2169 } *data;
2170
2171 ENTER();
2172
2173 /* Only high speed but not supported by gadget? */
2174 if (unlikely(!(full | high)))
2175 return -ENOTSUPP;
2176
2177 /* Allocate */
2178 data = kmalloc(sizeof *data, GFP_KERNEL);
2179 if (unlikely(!data))
2180 return -ENOMEM;
2181
2182 /* Zero */
2183 memset(data->eps, 0, sizeof data->eps);
2184 memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs);
2185 memset(data->inums, 0xff, sizeof data->inums);
2186 for (ret = ffs->eps_count; ret; --ret)
2187 data->eps[ret].num = -1;
2188
2189 /* Save pointers */
2190 func->eps = data->eps;
2191 func->interfaces_nums = data->inums;
2192
2193 /*
2194 * Go through all the endpoint descriptors and allocate
2195 * endpoints first, so that later we can rewrite the endpoint
2196 * numbers without worrying that it may be described later on.
2197 */
2198 if (likely(full)) {
2199 func->function.descriptors = data->fs_descs;
2200 ret = ffs_do_descs(ffs->fs_descs_count,
2201 data->raw_descs,
2202 sizeof data->raw_descs,
2203 __ffs_func_bind_do_descs, func);
2204 if (unlikely(ret < 0))
2205 goto error;
2206 } else {
2207 ret = 0;
2208 }
2209
2210 if (likely(high)) {
2211 func->function.hs_descriptors = data->hs_descs;
2212 ret = ffs_do_descs(ffs->hs_descs_count,
2213 data->raw_descs + ret,
2214 (sizeof data->raw_descs) - ret,
2215 __ffs_func_bind_do_descs, func);
2216 }
2217
2218 /*
2219 * Now handle interface numbers allocation and interface and
2220 * endpoint numbers rewriting. We can do that in one go
2221 * now.
2222 */
2223 ret = ffs_do_descs(ffs->fs_descs_count +
2224 (high ? ffs->hs_descs_count : 0),
2225 data->raw_descs, sizeof data->raw_descs,
2226 __ffs_func_bind_do_nums, func);
2227 if (unlikely(ret < 0))
2228 goto error;
2229
2230 /* And we're done */
2231 ffs_event_add(ffs, FUNCTIONFS_BIND);
2232 return 0;
2233
2234 error:
2235 /* XXX Do we need to release all claimed endpoints here? */
2236 return ret;
2237 }
2238
2239
2240 /* Other USB function hooks *************************************************/
2241
2242 static void ffs_func_unbind(struct usb_configuration *c,
2243 struct usb_function *f)
2244 {
2245 struct ffs_function *func = ffs_func_from_usb(f);
2246 struct ffs_data *ffs = func->ffs;
2247
2248 ENTER();
2249
2250 if (ffs->func == func) {
2251 ffs_func_eps_disable(func);
2252 ffs->func = NULL;
2253 }
2254
2255 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
2256
2257 ffs_func_free(func);
2258 }
2259
2260 static int ffs_func_set_alt(struct usb_function *f,
2261 unsigned interface, unsigned alt)
2262 {
2263 struct ffs_function *func = ffs_func_from_usb(f);
2264 struct ffs_data *ffs = func->ffs;
2265 int ret = 0, intf;
2266
2267 if (alt != (unsigned)-1) {
2268 intf = ffs_func_revmap_intf(func, interface);
2269 if (unlikely(intf < 0))
2270 return intf;
2271 }
2272
2273 if (ffs->func)
2274 ffs_func_eps_disable(ffs->func);
2275
2276 if (ffs->state != FFS_ACTIVE)
2277 return -ENODEV;
2278
2279 if (alt == (unsigned)-1) {
2280 ffs->func = NULL;
2281 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2282 return 0;
2283 }
2284
2285 ffs->func = func;
2286 ret = ffs_func_eps_enable(func);
2287 if (likely(ret >= 0))
2288 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2289 return ret;
2290 }
2291
2292 static void ffs_func_disable(struct usb_function *f)
2293 {
2294 ffs_func_set_alt(f, 0, (unsigned)-1);
2295 }
2296
2297 static int ffs_func_setup(struct usb_function *f,
2298 const struct usb_ctrlrequest *creq)
2299 {
2300 struct ffs_function *func = ffs_func_from_usb(f);
2301 struct ffs_data *ffs = func->ffs;
2302 unsigned long flags;
2303 int ret;
2304
2305 ENTER();
2306
2307 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2308 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
2309 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
2310 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
2311 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
2312
2313 /*
2314 * Most requests directed to interface go through here
2315 * (notable exceptions are set/get interface) so we need to
2316 * handle them. All other either handled by composite or
2317 * passed to usb_configuration->setup() (if one is set). No
2318 * matter, we will handle requests directed to endpoint here
2319 * as well (as it's straightforward) but what to do with any
2320 * other request?
2321 */
2322 if (ffs->state != FFS_ACTIVE)
2323 return -ENODEV;
2324
2325 switch (creq->bRequestType & USB_RECIP_MASK) {
2326 case USB_RECIP_INTERFACE:
2327 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2328 if (unlikely(ret < 0))
2329 return ret;
2330 break;
2331
2332 case USB_RECIP_ENDPOINT:
2333 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2334 if (unlikely(ret < 0))
2335 return ret;
2336 break;
2337
2338 default:
2339 return -EOPNOTSUPP;
2340 }
2341
2342 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2343 ffs->ev.setup = *creq;
2344 ffs->ev.setup.wIndex = cpu_to_le16(ret);
2345 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2346 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2347
2348 return 0;
2349 }
2350
2351 static void ffs_func_suspend(struct usb_function *f)
2352 {
2353 ENTER();
2354 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2355 }
2356
2357 static void ffs_func_resume(struct usb_function *f)
2358 {
2359 ENTER();
2360 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2361 }
2362
2363
2364 /* Endpoint and interface numbers reverse mapping ***************************/
2365
2366 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
2367 {
2368 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
2369 return num ? num : -EDOM;
2370 }
2371
2372 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
2373 {
2374 short *nums = func->interfaces_nums;
2375 unsigned count = func->ffs->interfaces_count;
2376
2377 for (; count; --count, ++nums) {
2378 if (*nums >= 0 && *nums == intf)
2379 return nums - func->interfaces_nums;
2380 }
2381
2382 return -EDOM;
2383 }
2384
2385
2386 /* Misc helper functions ****************************************************/
2387
2388 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
2389 {
2390 return nonblock
2391 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
2392 : mutex_lock_interruptible(mutex);
2393 }
2394
2395 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
2396 {
2397 char *data;
2398
2399 if (unlikely(!len))
2400 return NULL;
2401
2402 data = kmalloc(len, GFP_KERNEL);
2403 if (unlikely(!data))
2404 return ERR_PTR(-ENOMEM);
2405
2406 if (unlikely(__copy_from_user(data, buf, len))) {
2407 kfree(data);
2408 return ERR_PTR(-EFAULT);
2409 }
2410
2411 pr_vdebug("Buffer from user space:\n");
2412 ffs_dump_mem("", data, len);
2413
2414 return data;
2415 }
kernel source for telekom puls (alcatel/mediatek)