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1/*
2 * inode.c -- user mode filesystem api for usb gadget controllers
3 *
4 * Copyright (C) 2003-2004 David Brownell
5 * Copyright (C) 2003 Agilent Technologies
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13
14/* #define VERBOSE_DEBUG */
15
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/fs.h>
19#include <linux/pagemap.h>
20#include <linux/uts.h>
21#include <linux/wait.h>
22#include <linux/compiler.h>
23#include <asm/uaccess.h>
24#include <linux/sched.h>
25#include <linux/slab.h>
26#include <linux/poll.h>
27#include <linux/mmu_context.h>
28#include <linux/aio.h>
29
30#include <linux/device.h>
31#include <linux/moduleparam.h>
32
33#include <linux/usb/gadgetfs.h>
34#include <linux/usb/gadget.h>
35
36
37/*
38 * The gadgetfs API maps each endpoint to a file descriptor so that you
39 * can use standard synchronous read/write calls for I/O. There's some
40 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
41 * drivers show how this works in practice. You can also use AIO to
42 * eliminate I/O gaps between requests, to help when streaming data.
43 *
44 * Key parts that must be USB-specific are protocols defining how the
45 * read/write operations relate to the hardware state machines. There
46 * are two types of files. One type is for the device, implementing ep0.
47 * The other type is for each IN or OUT endpoint. In both cases, the
48 * user mode driver must configure the hardware before using it.
49 *
50 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
51 * (by writing configuration and device descriptors). Afterwards it
52 * may serve as a source of device events, used to handle all control
53 * requests other than basic enumeration.
54 *
55 * - Then, after a SET_CONFIGURATION control request, ep_config() is
56 * called when each /dev/gadget/ep* file is configured (by writing
57 * endpoint descriptors). Afterwards these files are used to write()
58 * IN data or to read() OUT data. To halt the endpoint, a "wrong
59 * direction" request is issued (like reading an IN endpoint).
60 *
61 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
62 * not possible on all hardware. For example, precise fault handling with
63 * respect to data left in endpoint fifos after aborted operations; or
64 * selective clearing of endpoint halts, to implement SET_INTERFACE.
65 */
66
67#define DRIVER_DESC "USB Gadget filesystem"
68#define DRIVER_VERSION "24 Aug 2004"
69
70static const char driver_desc [] = DRIVER_DESC;
71static const char shortname [] = "gadgetfs";
72
73MODULE_DESCRIPTION (DRIVER_DESC);
74MODULE_AUTHOR ("David Brownell");
75MODULE_LICENSE ("GPL");
76
77
78/*----------------------------------------------------------------------*/
79
80#define GADGETFS_MAGIC 0xaee71ee7
81
82/* /dev/gadget/$CHIP represents ep0 and the whole device */
83enum ep0_state {
84 /* DISBLED is the initial state.
85 */
86 STATE_DEV_DISABLED = 0,
87
88 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
89 * ep0/device i/o modes and binding to the controller. Driver
90 * must always write descriptors to initialize the device, then
91 * the device becomes UNCONNECTED until enumeration.
92 */
93 STATE_DEV_OPENED,
94
95 /* From then on, ep0 fd is in either of two basic modes:
96 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
97 * - SETUP: read/write will transfer control data and succeed;
98 * or if "wrong direction", performs protocol stall
99 */
100 STATE_DEV_UNCONNECTED,
101 STATE_DEV_CONNECTED,
102 STATE_DEV_SETUP,
103
104 /* UNBOUND means the driver closed ep0, so the device won't be
105 * accessible again (DEV_DISABLED) until all fds are closed.
106 */
107 STATE_DEV_UNBOUND,
108};
109
110/* enough for the whole queue: most events invalidate others */
111#define N_EVENT 5
112
113struct dev_data {
114 spinlock_t lock;
115 atomic_t count;
116 enum ep0_state state; /* P: lock */
117 struct usb_gadgetfs_event event [N_EVENT];
118 unsigned ev_next;
119 struct fasync_struct *fasync;
120 u8 current_config;
121
122 /* drivers reading ep0 MUST handle control requests (SETUP)
123 * reported that way; else the host will time out.
124 */
125 unsigned usermode_setup : 1,
126 setup_in : 1,
127 setup_can_stall : 1,
128 setup_out_ready : 1,
129 setup_out_error : 1,
130 setup_abort : 1;
131 unsigned setup_wLength;
132
133 /* the rest is basically write-once */
134 struct usb_config_descriptor *config, *hs_config;
135 struct usb_device_descriptor *dev;
136 struct usb_request *req;
137 struct usb_gadget *gadget;
138 struct list_head epfiles;
139 void *buf;
140 wait_queue_head_t wait;
141 struct super_block *sb;
142 struct dentry *dentry;
143
144 /* except this scratch i/o buffer for ep0 */
145 u8 rbuf [256];
146};
147
148static inline void get_dev (struct dev_data *data)
149{
150 atomic_inc (&data->count);
151}
152
153static void put_dev (struct dev_data *data)
154{
155 if (likely (!atomic_dec_and_test (&data->count)))
156 return;
157 /* needs no more cleanup */
158 BUG_ON (waitqueue_active (&data->wait));
159 kfree (data);
160}
161
162static struct dev_data *dev_new (void)
163{
164 struct dev_data *dev;
165
166 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
167 if (!dev)
168 return NULL;
169 dev->state = STATE_DEV_DISABLED;
170 atomic_set (&dev->count, 1);
171 spin_lock_init (&dev->lock);
172 INIT_LIST_HEAD (&dev->epfiles);
173 init_waitqueue_head (&dev->wait);
174 return dev;
175}
176
177/*----------------------------------------------------------------------*/
178
179/* other /dev/gadget/$ENDPOINT files represent endpoints */
180enum ep_state {
181 STATE_EP_DISABLED = 0,
182 STATE_EP_READY,
183 STATE_EP_ENABLED,
184 STATE_EP_UNBOUND,
185};
186
187struct ep_data {
188 struct mutex lock;
189 enum ep_state state;
190 atomic_t count;
191 struct dev_data *dev;
192 /* must hold dev->lock before accessing ep or req */
193 struct usb_ep *ep;
194 struct usb_request *req;
195 ssize_t status;
196 char name [16];
197 struct usb_endpoint_descriptor desc, hs_desc;
198 struct list_head epfiles;
199 wait_queue_head_t wait;
200 struct dentry *dentry;
201 struct inode *inode;
202};
203
204static inline void get_ep (struct ep_data *data)
205{
206 atomic_inc (&data->count);
207}
208
209static void put_ep (struct ep_data *data)
210{
211 if (likely (!atomic_dec_and_test (&data->count)))
212 return;
213 put_dev (data->dev);
214 /* needs no more cleanup */
215 BUG_ON (!list_empty (&data->epfiles));
216 BUG_ON (waitqueue_active (&data->wait));
217 kfree (data);
218}
219
220/*----------------------------------------------------------------------*/
221
222/* most "how to use the hardware" policy choices are in userspace:
223 * mapping endpoint roles (which the driver needs) to the capabilities
224 * which the usb controller has. most of those capabilities are exposed
225 * implicitly, starting with the driver name and then endpoint names.
226 */
227
228static const char *CHIP;
229
230/*----------------------------------------------------------------------*/
231
232/* NOTE: don't use dev_printk calls before binding to the gadget
233 * at the end of ep0 configuration, or after unbind.
234 */
235
236/* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
237#define xprintk(d,level,fmt,args...) \
238 printk(level "%s: " fmt , shortname , ## args)
239
240#ifdef DEBUG
241#define DBG(dev,fmt,args...) \
242 xprintk(dev , KERN_DEBUG , fmt , ## args)
243#else
244#define DBG(dev,fmt,args...) \
245 do { } while (0)
246#endif /* DEBUG */
247
248#ifdef VERBOSE_DEBUG
249#define VDEBUG DBG
250#else
251#define VDEBUG(dev,fmt,args...) \
252 do { } while (0)
253#endif /* DEBUG */
254
255#define ERROR(dev,fmt,args...) \
256 xprintk(dev , KERN_ERR , fmt , ## args)
257#define INFO(dev,fmt,args...) \
258 xprintk(dev , KERN_INFO , fmt , ## args)
259
260
261/*----------------------------------------------------------------------*/
262
263/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
264 *
265 * After opening, configure non-control endpoints. Then use normal
266 * stream read() and write() requests; and maybe ioctl() to get more
267 * precise FIFO status when recovering from cancellation.
268 */
269
270static void epio_complete (struct usb_ep *ep, struct usb_request *req)
271{
272 struct ep_data *epdata = ep->driver_data;
273
274 if (!req->context)
275 return;
276 if (req->status)
277 epdata->status = req->status;
278 else
279 epdata->status = req->actual;
280 complete ((struct completion *)req->context);
281}
282
283/* tasklock endpoint, returning when it's connected.
284 * still need dev->lock to use epdata->ep.
285 */
286static int
287get_ready_ep (unsigned f_flags, struct ep_data *epdata)
288{
289 int val;
290
291 if (f_flags & O_NONBLOCK) {
292 if (!mutex_trylock(&epdata->lock))
293 goto nonblock;
294 if (epdata->state != STATE_EP_ENABLED) {
295 mutex_unlock(&epdata->lock);
296nonblock:
297 val = -EAGAIN;
298 } else
299 val = 0;
300 return val;
301 }
302
303 val = mutex_lock_interruptible(&epdata->lock);
304 if (val < 0)
305 return val;
306
307 switch (epdata->state) {
308 case STATE_EP_ENABLED:
309 break;
310 // case STATE_EP_DISABLED: /* "can't happen" */
311 // case STATE_EP_READY: /* "can't happen" */
312 default: /* error! */
313 pr_debug ("%s: ep %p not available, state %d\n",
314 shortname, epdata, epdata->state);
315 // FALLTHROUGH
316 case STATE_EP_UNBOUND: /* clean disconnect */
317 val = -ENODEV;
318 mutex_unlock(&epdata->lock);
319 }
320 return val;
321}
322
323static ssize_t
324ep_io (struct ep_data *epdata, void *buf, unsigned len)
325{
326 DECLARE_COMPLETION_ONSTACK (done);
327 int value;
328
329 spin_lock_irq (&epdata->dev->lock);
330 if (likely (epdata->ep != NULL)) {
331 struct usb_request *req = epdata->req;
332
333 req->context = &done;
334 req->complete = epio_complete;
335 req->buf = buf;
336 req->length = len;
337 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
338 } else
339 value = -ENODEV;
340 spin_unlock_irq (&epdata->dev->lock);
341
342 if (likely (value == 0)) {
343 value = wait_event_interruptible (done.wait, done.done);
344 if (value != 0) {
345 spin_lock_irq (&epdata->dev->lock);
346 if (likely (epdata->ep != NULL)) {
347 DBG (epdata->dev, "%s i/o interrupted\n",
348 epdata->name);
349 usb_ep_dequeue (epdata->ep, epdata->req);
350 spin_unlock_irq (&epdata->dev->lock);
351
352 wait_event (done.wait, done.done);
353 if (epdata->status == -ECONNRESET)
354 epdata->status = -EINTR;
355 } else {
356 spin_unlock_irq (&epdata->dev->lock);
357
358 DBG (epdata->dev, "endpoint gone\n");
359 epdata->status = -ENODEV;
360 }
361 }
362 return epdata->status;
363 }
364 return value;
365}
366
367
368/* handle a synchronous OUT bulk/intr/iso transfer */
369static ssize_t
370ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
371{
372 struct ep_data *data = fd->private_data;
373 void *kbuf;
374 ssize_t value;
375
376 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
377 return value;
378
379 /* halt any endpoint by doing a "wrong direction" i/o call */
380 if (usb_endpoint_dir_in(&data->desc)) {
381 if (usb_endpoint_xfer_isoc(&data->desc)) {
382 mutex_unlock(&data->lock);
383 return -EINVAL;
384 }
385 DBG (data->dev, "%s halt\n", data->name);
386 spin_lock_irq (&data->dev->lock);
387 if (likely (data->ep != NULL))
388 usb_ep_set_halt (data->ep);
389 spin_unlock_irq (&data->dev->lock);
390 mutex_unlock(&data->lock);
391 return -EBADMSG;
392 }
393
394 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
395
396 value = -ENOMEM;
397 kbuf = kmalloc (len, GFP_KERNEL);
398 if (unlikely (!kbuf))
399 goto free1;
400
401 value = ep_io (data, kbuf, len);
402 VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
403 data->name, len, (int) value);
404 if (value >= 0 && copy_to_user (buf, kbuf, value))
405 value = -EFAULT;
406
407free1:
408 mutex_unlock(&data->lock);
409 kfree (kbuf);
410 return value;
411}
412
413/* handle a synchronous IN bulk/intr/iso transfer */
414static ssize_t
415ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
416{
417 struct ep_data *data = fd->private_data;
418 void *kbuf;
419 ssize_t value;
420
421 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
422 return value;
423
424 /* halt any endpoint by doing a "wrong direction" i/o call */
425 if (!usb_endpoint_dir_in(&data->desc)) {
426 if (usb_endpoint_xfer_isoc(&data->desc)) {
427 mutex_unlock(&data->lock);
428 return -EINVAL;
429 }
430 DBG (data->dev, "%s halt\n", data->name);
431 spin_lock_irq (&data->dev->lock);
432 if (likely (data->ep != NULL))
433 usb_ep_set_halt (data->ep);
434 spin_unlock_irq (&data->dev->lock);
435 mutex_unlock(&data->lock);
436 return -EBADMSG;
437 }
438
439 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
440
441 value = -ENOMEM;
442 kbuf = memdup_user(buf, len);
443 if (!kbuf) {
444 value = PTR_ERR(kbuf);
445 goto free1;
446 }
447
448 value = ep_io (data, kbuf, len);
449 VDEBUG (data->dev, "%s write %zu IN, status %d\n",
450 data->name, len, (int) value);
451free1:
452 mutex_unlock(&data->lock);
453 return value;
454}
455
456static int
457ep_release (struct inode *inode, struct file *fd)
458{
459 struct ep_data *data = fd->private_data;
460 int value;
461
462 value = mutex_lock_interruptible(&data->lock);
463 if (value < 0)
464 return value;
465
466 /* clean up if this can be reopened */
467 if (data->state != STATE_EP_UNBOUND) {
468 data->state = STATE_EP_DISABLED;
469 data->desc.bDescriptorType = 0;
470 data->hs_desc.bDescriptorType = 0;
471 usb_ep_disable(data->ep);
472 }
473 mutex_unlock(&data->lock);
474 put_ep (data);
475 return 0;
476}
477
478static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
479{
480 struct ep_data *data = fd->private_data;
481 int status;
482
483 if ((status = get_ready_ep (fd->f_flags, data)) < 0)
484 return status;
485
486 spin_lock_irq (&data->dev->lock);
487 if (likely (data->ep != NULL)) {
488 switch (code) {
489 case GADGETFS_FIFO_STATUS:
490 status = usb_ep_fifo_status (data->ep);
491 break;
492 case GADGETFS_FIFO_FLUSH:
493 usb_ep_fifo_flush (data->ep);
494 break;
495 case GADGETFS_CLEAR_HALT:
496 status = usb_ep_clear_halt (data->ep);
497 break;
498 default:
499 status = -ENOTTY;
500 }
501 } else
502 status = -ENODEV;
503 spin_unlock_irq (&data->dev->lock);
504 mutex_unlock(&data->lock);
505 return status;
506}
507
508/*----------------------------------------------------------------------*/
509
510/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
511
512struct kiocb_priv {
513 struct usb_request *req;
514 struct ep_data *epdata;
515 struct kiocb *iocb;
516 struct mm_struct *mm;
517 struct work_struct work;
518 void *buf;
519 const struct iovec *iv;
520 unsigned long nr_segs;
521 unsigned actual;
522};
523
524static int ep_aio_cancel(struct kiocb *iocb)
525{
526 struct kiocb_priv *priv = iocb->private;
527 struct ep_data *epdata;
528 int value;
529
530 local_irq_disable();
531 epdata = priv->epdata;
532 // spin_lock(&epdata->dev->lock);
533 if (likely(epdata && epdata->ep && priv->req))
534 value = usb_ep_dequeue (epdata->ep, priv->req);
535 else
536 value = -EINVAL;
537 // spin_unlock(&epdata->dev->lock);
538 local_irq_enable();
539
540 return value;
541}
542
543static ssize_t ep_copy_to_user(struct kiocb_priv *priv)
544{
545 ssize_t len, total;
546 void *to_copy;
547 int i;
548
549 /* copy stuff into user buffers */
550 total = priv->actual;
551 len = 0;
552 to_copy = priv->buf;
553 for (i=0; i < priv->nr_segs; i++) {
554 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
555
556 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
557 if (len == 0)
558 len = -EFAULT;
559 break;
560 }
561
562 total -= this;
563 len += this;
564 to_copy += this;
565 if (total == 0)
566 break;
567 }
568
569 return len;
570}
571
572static void ep_user_copy_worker(struct work_struct *work)
573{
574 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
575 struct mm_struct *mm = priv->mm;
576 struct kiocb *iocb = priv->iocb;
577 size_t ret;
578
579 use_mm(mm);
580 ret = ep_copy_to_user(priv);
581 unuse_mm(mm);
582
583 /* completing the iocb can drop the ctx and mm, don't touch mm after */
584 aio_complete(iocb, ret, ret);
585
586 kfree(priv->buf);
587 kfree(priv);
588}
589
590static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
591{
592 struct kiocb *iocb = req->context;
593 struct kiocb_priv *priv = iocb->private;
594 struct ep_data *epdata = priv->epdata;
595
596 /* lock against disconnect (and ideally, cancel) */
597 spin_lock(&epdata->dev->lock);
598 priv->req = NULL;
599 priv->epdata = NULL;
600
601 /* if this was a write or a read returning no data then we
602 * don't need to copy anything to userspace, so we can
603 * complete the aio request immediately.
604 */
605 if (priv->iv == NULL || unlikely(req->actual == 0)) {
606 kfree(req->buf);
607 kfree(priv);
608 iocb->private = NULL;
609 /* aio_complete() reports bytes-transferred _and_ faults */
610 aio_complete(iocb, req->actual ? req->actual : req->status,
611 req->status);
612 } else {
613 /* ep_copy_to_user() won't report both; we hide some faults */
614 if (unlikely(0 != req->status))
615 DBG(epdata->dev, "%s fault %d len %d\n",
616 ep->name, req->status, req->actual);
617
618 priv->buf = req->buf;
619 priv->actual = req->actual;
620 schedule_work(&priv->work);
621 }
622 spin_unlock(&epdata->dev->lock);
623
624 usb_ep_free_request(ep, req);
625 put_ep(epdata);
626}
627
628static ssize_t
629ep_aio_rwtail(
630 struct kiocb *iocb,
631 char *buf,
632 size_t len,
633 struct ep_data *epdata,
634 const struct iovec *iv,
635 unsigned long nr_segs
636)
637{
638 struct kiocb_priv *priv;
639 struct usb_request *req;
640 ssize_t value;
641
642 priv = kmalloc(sizeof *priv, GFP_KERNEL);
643 if (!priv) {
644 value = -ENOMEM;
645fail:
646 kfree(buf);
647 return value;
648 }
649 iocb->private = priv;
650 priv->iocb = iocb;
651 priv->iv = iv;
652 priv->nr_segs = nr_segs;
653 INIT_WORK(&priv->work, ep_user_copy_worker);
654
655 value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
656 if (unlikely(value < 0)) {
657 kfree(priv);
658 goto fail;
659 }
660
661 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
662 get_ep(epdata);
663 priv->epdata = epdata;
664 priv->actual = 0;
665 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
666
667 /* each kiocb is coupled to one usb_request, but we can't
668 * allocate or submit those if the host disconnected.
669 */
670 spin_lock_irq(&epdata->dev->lock);
671 if (likely(epdata->ep)) {
672 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
673 if (likely(req)) {
674 priv->req = req;
675 req->buf = buf;
676 req->length = len;
677 req->complete = ep_aio_complete;
678 req->context = iocb;
679 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
680 if (unlikely(0 != value))
681 usb_ep_free_request(epdata->ep, req);
682 } else
683 value = -EAGAIN;
684 } else
685 value = -ENODEV;
686 spin_unlock_irq(&epdata->dev->lock);
687
688 mutex_unlock(&epdata->lock);
689
690 if (unlikely(value)) {
691 kfree(priv);
692 put_ep(epdata);
693 } else
694 value = -EIOCBQUEUED;
695 return value;
696}
697
698static ssize_t
699ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
700 unsigned long nr_segs, loff_t o)
701{
702 struct ep_data *epdata = iocb->ki_filp->private_data;
703 char *buf;
704
705 if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
706 return -EINVAL;
707
708 buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
709 if (unlikely(!buf))
710 return -ENOMEM;
711
712 return ep_aio_rwtail(iocb, buf, iocb->ki_nbytes, epdata, iov, nr_segs);
713}
714
715static ssize_t
716ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
717 unsigned long nr_segs, loff_t o)
718{
719 struct ep_data *epdata = iocb->ki_filp->private_data;
720 char *buf;
721 size_t len = 0;
722 int i = 0;
723
724 if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
725 return -EINVAL;
726
727 buf = kmalloc(iocb->ki_nbytes, GFP_KERNEL);
728 if (unlikely(!buf))
729 return -ENOMEM;
730
731 for (i=0; i < nr_segs; i++) {
732 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
733 iov[i].iov_len) != 0)) {
734 kfree(buf);
735 return -EFAULT;
736 }
737 len += iov[i].iov_len;
738 }
739 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
740}
741
742/*----------------------------------------------------------------------*/
743
744/* used after endpoint configuration */
745static const struct file_operations ep_io_operations = {
746 .owner = THIS_MODULE,
747 .llseek = no_llseek,
748
749 .read = ep_read,
750 .write = ep_write,
751 .unlocked_ioctl = ep_ioctl,
752 .release = ep_release,
753
754 .aio_read = ep_aio_read,
755 .aio_write = ep_aio_write,
756};
757
758/* ENDPOINT INITIALIZATION
759 *
760 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
761 * status = write (fd, descriptors, sizeof descriptors)
762 *
763 * That write establishes the endpoint configuration, configuring
764 * the controller to process bulk, interrupt, or isochronous transfers
765 * at the right maxpacket size, and so on.
766 *
767 * The descriptors are message type 1, identified by a host order u32
768 * at the beginning of what's written. Descriptor order is: full/low
769 * speed descriptor, then optional high speed descriptor.
770 */
771static ssize_t
772ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
773{
774 struct ep_data *data = fd->private_data;
775 struct usb_ep *ep;
776 u32 tag;
777 int value, length = len;
778
779 value = mutex_lock_interruptible(&data->lock);
780 if (value < 0)
781 return value;
782
783 if (data->state != STATE_EP_READY) {
784 value = -EL2HLT;
785 goto fail;
786 }
787
788 value = len;
789 if (len < USB_DT_ENDPOINT_SIZE + 4)
790 goto fail0;
791
792 /* we might need to change message format someday */
793 if (copy_from_user (&tag, buf, 4)) {
794 goto fail1;
795 }
796 if (tag != 1) {
797 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
798 goto fail0;
799 }
800 buf += 4;
801 len -= 4;
802
803 /* NOTE: audio endpoint extensions not accepted here;
804 * just don't include the extra bytes.
805 */
806
807 /* full/low speed descriptor, then high speed */
808 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
809 goto fail1;
810 }
811 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
812 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
813 goto fail0;
814 if (len != USB_DT_ENDPOINT_SIZE) {
815 if (len != 2 * USB_DT_ENDPOINT_SIZE)
816 goto fail0;
817 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
818 USB_DT_ENDPOINT_SIZE)) {
819 goto fail1;
820 }
821 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
822 || data->hs_desc.bDescriptorType
823 != USB_DT_ENDPOINT) {
824 DBG(data->dev, "config %s, bad hs length or type\n",
825 data->name);
826 goto fail0;
827 }
828 }
829
830 spin_lock_irq (&data->dev->lock);
831 if (data->dev->state == STATE_DEV_UNBOUND) {
832 value = -ENOENT;
833 goto gone;
834 } else if ((ep = data->ep) == NULL) {
835 value = -ENODEV;
836 goto gone;
837 }
838 switch (data->dev->gadget->speed) {
839 case USB_SPEED_LOW:
840 case USB_SPEED_FULL:
841 ep->desc = &data->desc;
842 value = usb_ep_enable(ep);
843 if (value == 0)
844 data->state = STATE_EP_ENABLED;
845 break;
846 case USB_SPEED_HIGH:
847 /* fails if caller didn't provide that descriptor... */
848 ep->desc = &data->hs_desc;
849 value = usb_ep_enable(ep);
850 if (value == 0)
851 data->state = STATE_EP_ENABLED;
852 break;
853 default:
854 DBG(data->dev, "unconnected, %s init abandoned\n",
855 data->name);
856 value = -EINVAL;
857 }
858 if (value == 0) {
859 fd->f_op = &ep_io_operations;
860 value = length;
861 }
862gone:
863 spin_unlock_irq (&data->dev->lock);
864 if (value < 0) {
865fail:
866 data->desc.bDescriptorType = 0;
867 data->hs_desc.bDescriptorType = 0;
868 }
869 mutex_unlock(&data->lock);
870 return value;
871fail0:
872 value = -EINVAL;
873 goto fail;
874fail1:
875 value = -EFAULT;
876 goto fail;
877}
878
879static int
880ep_open (struct inode *inode, struct file *fd)
881{
882 struct ep_data *data = inode->i_private;
883 int value = -EBUSY;
884
885 if (mutex_lock_interruptible(&data->lock) != 0)
886 return -EINTR;
887 spin_lock_irq (&data->dev->lock);
888 if (data->dev->state == STATE_DEV_UNBOUND)
889 value = -ENOENT;
890 else if (data->state == STATE_EP_DISABLED) {
891 value = 0;
892 data->state = STATE_EP_READY;
893 get_ep (data);
894 fd->private_data = data;
895 VDEBUG (data->dev, "%s ready\n", data->name);
896 } else
897 DBG (data->dev, "%s state %d\n",
898 data->name, data->state);
899 spin_unlock_irq (&data->dev->lock);
900 mutex_unlock(&data->lock);
901 return value;
902}
903
904/* used before endpoint configuration */
905static const struct file_operations ep_config_operations = {
906 .llseek = no_llseek,
907
908 .open = ep_open,
909 .write = ep_config,
910 .release = ep_release,
911};
912
913/*----------------------------------------------------------------------*/
914
915/* EP0 IMPLEMENTATION can be partly in userspace.
916 *
917 * Drivers that use this facility receive various events, including
918 * control requests the kernel doesn't handle. Drivers that don't
919 * use this facility may be too simple-minded for real applications.
920 */
921
922static inline void ep0_readable (struct dev_data *dev)
923{
924 wake_up (&dev->wait);
925 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
926}
927
928static void clean_req (struct usb_ep *ep, struct usb_request *req)
929{
930 struct dev_data *dev = ep->driver_data;
931
932 if (req->buf != dev->rbuf) {
933 kfree(req->buf);
934 req->buf = dev->rbuf;
935 }
936 req->complete = epio_complete;
937 dev->setup_out_ready = 0;
938}
939
940static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
941{
942 struct dev_data *dev = ep->driver_data;
943 unsigned long flags;
944 int free = 1;
945
946 /* for control OUT, data must still get to userspace */
947 spin_lock_irqsave(&dev->lock, flags);
948 if (!dev->setup_in) {
949 dev->setup_out_error = (req->status != 0);
950 if (!dev->setup_out_error)
951 free = 0;
952 dev->setup_out_ready = 1;
953 ep0_readable (dev);
954 }
955
956 /* clean up as appropriate */
957 if (free && req->buf != &dev->rbuf)
958 clean_req (ep, req);
959 req->complete = epio_complete;
960 spin_unlock_irqrestore(&dev->lock, flags);
961}
962
963static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
964{
965 struct dev_data *dev = ep->driver_data;
966
967 if (dev->setup_out_ready) {
968 DBG (dev, "ep0 request busy!\n");
969 return -EBUSY;
970 }
971 if (len > sizeof (dev->rbuf))
972 req->buf = kmalloc(len, GFP_ATOMIC);
973 if (req->buf == NULL) {
974 req->buf = dev->rbuf;
975 return -ENOMEM;
976 }
977 req->complete = ep0_complete;
978 req->length = len;
979 req->zero = 0;
980 return 0;
981}
982
983static ssize_t
984ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
985{
986 struct dev_data *dev = fd->private_data;
987 ssize_t retval;
988 enum ep0_state state;
989
990 spin_lock_irq (&dev->lock);
991
992 /* report fd mode change before acting on it */
993 if (dev->setup_abort) {
994 dev->setup_abort = 0;
995 retval = -EIDRM;
996 goto done;
997 }
998
999 /* control DATA stage */
1000 if ((state = dev->state) == STATE_DEV_SETUP) {
1001
1002 if (dev->setup_in) { /* stall IN */
1003 VDEBUG(dev, "ep0in stall\n");
1004 (void) usb_ep_set_halt (dev->gadget->ep0);
1005 retval = -EL2HLT;
1006 dev->state = STATE_DEV_CONNECTED;
1007
1008 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
1009 struct usb_ep *ep = dev->gadget->ep0;
1010 struct usb_request *req = dev->req;
1011
1012 if ((retval = setup_req (ep, req, 0)) == 0)
1013 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1014 dev->state = STATE_DEV_CONNECTED;
1015
1016 /* assume that was SET_CONFIGURATION */
1017 if (dev->current_config) {
1018 unsigned power;
1019
1020 if (gadget_is_dualspeed(dev->gadget)
1021 && (dev->gadget->speed
1022 == USB_SPEED_HIGH))
1023 power = dev->hs_config->bMaxPower;
1024 else
1025 power = dev->config->bMaxPower;
1026 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1027 }
1028
1029 } else { /* collect OUT data */
1030 if ((fd->f_flags & O_NONBLOCK) != 0
1031 && !dev->setup_out_ready) {
1032 retval = -EAGAIN;
1033 goto done;
1034 }
1035 spin_unlock_irq (&dev->lock);
1036 retval = wait_event_interruptible (dev->wait,
1037 dev->setup_out_ready != 0);
1038
1039 /* FIXME state could change from under us */
1040 spin_lock_irq (&dev->lock);
1041 if (retval)
1042 goto done;
1043
1044 if (dev->state != STATE_DEV_SETUP) {
1045 retval = -ECANCELED;
1046 goto done;
1047 }
1048 dev->state = STATE_DEV_CONNECTED;
1049
1050 if (dev->setup_out_error)
1051 retval = -EIO;
1052 else {
1053 len = min (len, (size_t)dev->req->actual);
1054// FIXME don't call this with the spinlock held ...
1055 if (copy_to_user (buf, dev->req->buf, len))
1056 retval = -EFAULT;
1057 else
1058 retval = len;
1059 clean_req (dev->gadget->ep0, dev->req);
1060 /* NOTE userspace can't yet choose to stall */
1061 }
1062 }
1063 goto done;
1064 }
1065
1066 /* else normal: return event data */
1067 if (len < sizeof dev->event [0]) {
1068 retval = -EINVAL;
1069 goto done;
1070 }
1071 len -= len % sizeof (struct usb_gadgetfs_event);
1072 dev->usermode_setup = 1;
1073
1074scan:
1075 /* return queued events right away */
1076 if (dev->ev_next != 0) {
1077 unsigned i, n;
1078
1079 n = len / sizeof (struct usb_gadgetfs_event);
1080 if (dev->ev_next < n)
1081 n = dev->ev_next;
1082
1083 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1084 for (i = 0; i < n; i++) {
1085 if (dev->event [i].type == GADGETFS_SETUP) {
1086 dev->state = STATE_DEV_SETUP;
1087 n = i + 1;
1088 break;
1089 }
1090 }
1091 spin_unlock_irq (&dev->lock);
1092 len = n * sizeof (struct usb_gadgetfs_event);
1093 if (copy_to_user (buf, &dev->event, len))
1094 retval = -EFAULT;
1095 else
1096 retval = len;
1097 if (len > 0) {
1098 /* NOTE this doesn't guard against broken drivers;
1099 * concurrent ep0 readers may lose events.
1100 */
1101 spin_lock_irq (&dev->lock);
1102 if (dev->ev_next > n) {
1103 memmove(&dev->event[0], &dev->event[n],
1104 sizeof (struct usb_gadgetfs_event)
1105 * (dev->ev_next - n));
1106 }
1107 dev->ev_next -= n;
1108 spin_unlock_irq (&dev->lock);
1109 }
1110 return retval;
1111 }
1112 if (fd->f_flags & O_NONBLOCK) {
1113 retval = -EAGAIN;
1114 goto done;
1115 }
1116
1117 switch (state) {
1118 default:
1119 DBG (dev, "fail %s, state %d\n", __func__, state);
1120 retval = -ESRCH;
1121 break;
1122 case STATE_DEV_UNCONNECTED:
1123 case STATE_DEV_CONNECTED:
1124 spin_unlock_irq (&dev->lock);
1125 DBG (dev, "%s wait\n", __func__);
1126
1127 /* wait for events */
1128 retval = wait_event_interruptible (dev->wait,
1129 dev->ev_next != 0);
1130 if (retval < 0)
1131 return retval;
1132 spin_lock_irq (&dev->lock);
1133 goto scan;
1134 }
1135
1136done:
1137 spin_unlock_irq (&dev->lock);
1138 return retval;
1139}
1140
1141static struct usb_gadgetfs_event *
1142next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1143{
1144 struct usb_gadgetfs_event *event;
1145 unsigned i;
1146
1147 switch (type) {
1148 /* these events purge the queue */
1149 case GADGETFS_DISCONNECT:
1150 if (dev->state == STATE_DEV_SETUP)
1151 dev->setup_abort = 1;
1152 // FALL THROUGH
1153 case GADGETFS_CONNECT:
1154 dev->ev_next = 0;
1155 break;
1156 case GADGETFS_SETUP: /* previous request timed out */
1157 case GADGETFS_SUSPEND: /* same effect */
1158 /* these events can't be repeated */
1159 for (i = 0; i != dev->ev_next; i++) {
1160 if (dev->event [i].type != type)
1161 continue;
1162 DBG(dev, "discard old event[%d] %d\n", i, type);
1163 dev->ev_next--;
1164 if (i == dev->ev_next)
1165 break;
1166 /* indices start at zero, for simplicity */
1167 memmove (&dev->event [i], &dev->event [i + 1],
1168 sizeof (struct usb_gadgetfs_event)
1169 * (dev->ev_next - i));
1170 }
1171 break;
1172 default:
1173 BUG ();
1174 }
1175 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1176 event = &dev->event [dev->ev_next++];
1177 BUG_ON (dev->ev_next > N_EVENT);
1178 memset (event, 0, sizeof *event);
1179 event->type = type;
1180 return event;
1181}
1182
1183static ssize_t
1184ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1185{
1186 struct dev_data *dev = fd->private_data;
1187 ssize_t retval = -ESRCH;
1188
1189 spin_lock_irq (&dev->lock);
1190
1191 /* report fd mode change before acting on it */
1192 if (dev->setup_abort) {
1193 dev->setup_abort = 0;
1194 retval = -EIDRM;
1195
1196 /* data and/or status stage for control request */
1197 } else if (dev->state == STATE_DEV_SETUP) {
1198
1199 /* IN DATA+STATUS caller makes len <= wLength */
1200 if (dev->setup_in) {
1201 retval = setup_req (dev->gadget->ep0, dev->req, len);
1202 if (retval == 0) {
1203 dev->state = STATE_DEV_CONNECTED;
1204 spin_unlock_irq (&dev->lock);
1205 if (copy_from_user (dev->req->buf, buf, len))
1206 retval = -EFAULT;
1207 else {
1208 if (len < dev->setup_wLength)
1209 dev->req->zero = 1;
1210 retval = usb_ep_queue (
1211 dev->gadget->ep0, dev->req,
1212 GFP_KERNEL);
1213 }
1214 if (retval < 0) {
1215 spin_lock_irq (&dev->lock);
1216 clean_req (dev->gadget->ep0, dev->req);
1217 spin_unlock_irq (&dev->lock);
1218 } else
1219 retval = len;
1220
1221 return retval;
1222 }
1223
1224 /* can stall some OUT transfers */
1225 } else if (dev->setup_can_stall) {
1226 VDEBUG(dev, "ep0out stall\n");
1227 (void) usb_ep_set_halt (dev->gadget->ep0);
1228 retval = -EL2HLT;
1229 dev->state = STATE_DEV_CONNECTED;
1230 } else {
1231 DBG(dev, "bogus ep0out stall!\n");
1232 }
1233 } else
1234 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1235
1236 spin_unlock_irq (&dev->lock);
1237 return retval;
1238}
1239
1240static int
1241ep0_fasync (int f, struct file *fd, int on)
1242{
1243 struct dev_data *dev = fd->private_data;
1244 // caller must F_SETOWN before signal delivery happens
1245 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1246 return fasync_helper (f, fd, on, &dev->fasync);
1247}
1248
1249static struct usb_gadget_driver gadgetfs_driver;
1250
1251static int
1252dev_release (struct inode *inode, struct file *fd)
1253{
1254 struct dev_data *dev = fd->private_data;
1255
1256 /* closing ep0 === shutdown all */
1257
1258 usb_gadget_unregister_driver (&gadgetfs_driver);
1259
1260 /* at this point "good" hardware has disconnected the
1261 * device from USB; the host won't see it any more.
1262 * alternatively, all host requests will time out.
1263 */
1264
1265 kfree (dev->buf);
1266 dev->buf = NULL;
1267 put_dev (dev);
1268
1269 return 0;
1270}
1271
1272static unsigned int
1273ep0_poll (struct file *fd, poll_table *wait)
1274{
1275 struct dev_data *dev = fd->private_data;
1276 int mask = 0;
1277
1278 poll_wait(fd, &dev->wait, wait);
1279
1280 spin_lock_irq (&dev->lock);
1281
1282 /* report fd mode change before acting on it */
1283 if (dev->setup_abort) {
1284 dev->setup_abort = 0;
1285 mask = POLLHUP;
1286 goto out;
1287 }
1288
1289 if (dev->state == STATE_DEV_SETUP) {
1290 if (dev->setup_in || dev->setup_can_stall)
1291 mask = POLLOUT;
1292 } else {
1293 if (dev->ev_next != 0)
1294 mask = POLLIN;
1295 }
1296out:
1297 spin_unlock_irq(&dev->lock);
1298 return mask;
1299}
1300
1301static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1302{
1303 struct dev_data *dev = fd->private_data;
1304 struct usb_gadget *gadget = dev->gadget;
1305 long ret = -ENOTTY;
1306
1307 if (gadget->ops->ioctl)
1308 ret = gadget->ops->ioctl (gadget, code, value);
1309
1310 return ret;
1311}
1312
1313/* used after device configuration */
1314static const struct file_operations ep0_io_operations = {
1315 .owner = THIS_MODULE,
1316 .llseek = no_llseek,
1317
1318 .read = ep0_read,
1319 .write = ep0_write,
1320 .fasync = ep0_fasync,
1321 .poll = ep0_poll,
1322 .unlocked_ioctl = dev_ioctl,
1323 .release = dev_release,
1324};
1325
1326/*----------------------------------------------------------------------*/
1327
1328/* The in-kernel gadget driver handles most ep0 issues, in particular
1329 * enumerating the single configuration (as provided from user space).
1330 *
1331 * Unrecognized ep0 requests may be handled in user space.
1332 */
1333
1334static void make_qualifier (struct dev_data *dev)
1335{
1336 struct usb_qualifier_descriptor qual;
1337 struct usb_device_descriptor *desc;
1338
1339 qual.bLength = sizeof qual;
1340 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1341 qual.bcdUSB = cpu_to_le16 (0x0200);
1342
1343 desc = dev->dev;
1344 qual.bDeviceClass = desc->bDeviceClass;
1345 qual.bDeviceSubClass = desc->bDeviceSubClass;
1346 qual.bDeviceProtocol = desc->bDeviceProtocol;
1347
1348 /* assumes ep0 uses the same value for both speeds ... */
1349 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1350
1351 qual.bNumConfigurations = 1;
1352 qual.bRESERVED = 0;
1353
1354 memcpy (dev->rbuf, &qual, sizeof qual);
1355}
1356
1357static int
1358config_buf (struct dev_data *dev, u8 type, unsigned index)
1359{
1360 int len;
1361 int hs = 0;
1362
1363 /* only one configuration */
1364 if (index > 0)
1365 return -EINVAL;
1366
1367 if (gadget_is_dualspeed(dev->gadget)) {
1368 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1369 if (type == USB_DT_OTHER_SPEED_CONFIG)
1370 hs = !hs;
1371 }
1372 if (hs) {
1373 dev->req->buf = dev->hs_config;
1374 len = le16_to_cpu(dev->hs_config->wTotalLength);
1375 } else {
1376 dev->req->buf = dev->config;
1377 len = le16_to_cpu(dev->config->wTotalLength);
1378 }
1379 ((u8 *)dev->req->buf) [1] = type;
1380 return len;
1381}
1382
1383static int
1384gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1385{
1386 struct dev_data *dev = get_gadget_data (gadget);
1387 struct usb_request *req = dev->req;
1388 int value = -EOPNOTSUPP;
1389 struct usb_gadgetfs_event *event;
1390 u16 w_value = le16_to_cpu(ctrl->wValue);
1391 u16 w_length = le16_to_cpu(ctrl->wLength);
1392
1393 spin_lock (&dev->lock);
1394 dev->setup_abort = 0;
1395 if (dev->state == STATE_DEV_UNCONNECTED) {
1396 if (gadget_is_dualspeed(gadget)
1397 && gadget->speed == USB_SPEED_HIGH
1398 && dev->hs_config == NULL) {
1399 spin_unlock(&dev->lock);
1400 ERROR (dev, "no high speed config??\n");
1401 return -EINVAL;
1402 }
1403
1404 dev->state = STATE_DEV_CONNECTED;
1405
1406 INFO (dev, "connected\n");
1407 event = next_event (dev, GADGETFS_CONNECT);
1408 event->u.speed = gadget->speed;
1409 ep0_readable (dev);
1410
1411 /* host may have given up waiting for response. we can miss control
1412 * requests handled lower down (device/endpoint status and features);
1413 * then ep0_{read,write} will report the wrong status. controller
1414 * driver will have aborted pending i/o.
1415 */
1416 } else if (dev->state == STATE_DEV_SETUP)
1417 dev->setup_abort = 1;
1418
1419 req->buf = dev->rbuf;
1420 req->context = NULL;
1421 value = -EOPNOTSUPP;
1422 switch (ctrl->bRequest) {
1423
1424 case USB_REQ_GET_DESCRIPTOR:
1425 if (ctrl->bRequestType != USB_DIR_IN)
1426 goto unrecognized;
1427 switch (w_value >> 8) {
1428
1429 case USB_DT_DEVICE:
1430 value = min (w_length, (u16) sizeof *dev->dev);
1431 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1432 req->buf = dev->dev;
1433 break;
1434 case USB_DT_DEVICE_QUALIFIER:
1435 if (!dev->hs_config)
1436 break;
1437 value = min (w_length, (u16)
1438 sizeof (struct usb_qualifier_descriptor));
1439 make_qualifier (dev);
1440 break;
1441 case USB_DT_OTHER_SPEED_CONFIG:
1442 // FALLTHROUGH
1443 case USB_DT_CONFIG:
1444 value = config_buf (dev,
1445 w_value >> 8,
1446 w_value & 0xff);
1447 if (value >= 0)
1448 value = min (w_length, (u16) value);
1449 break;
1450 case USB_DT_STRING:
1451 goto unrecognized;
1452
1453 default: // all others are errors
1454 break;
1455 }
1456 break;
1457
1458 /* currently one config, two speeds */
1459 case USB_REQ_SET_CONFIGURATION:
1460 if (ctrl->bRequestType != 0)
1461 goto unrecognized;
1462 if (0 == (u8) w_value) {
1463 value = 0;
1464 dev->current_config = 0;
1465 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1466 // user mode expected to disable endpoints
1467 } else {
1468 u8 config, power;
1469
1470 if (gadget_is_dualspeed(gadget)
1471 && gadget->speed == USB_SPEED_HIGH) {
1472 config = dev->hs_config->bConfigurationValue;
1473 power = dev->hs_config->bMaxPower;
1474 } else {
1475 config = dev->config->bConfigurationValue;
1476 power = dev->config->bMaxPower;
1477 }
1478
1479 if (config == (u8) w_value) {
1480 value = 0;
1481 dev->current_config = config;
1482 usb_gadget_vbus_draw(gadget, 2 * power);
1483 }
1484 }
1485
1486 /* report SET_CONFIGURATION like any other control request,
1487 * except that usermode may not stall this. the next
1488 * request mustn't be allowed start until this finishes:
1489 * endpoints and threads set up, etc.
1490 *
1491 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1492 * has bad/racey automagic that prevents synchronizing here.
1493 * even kernel mode drivers often miss them.
1494 */
1495 if (value == 0) {
1496 INFO (dev, "configuration #%d\n", dev->current_config);
1497 if (dev->usermode_setup) {
1498 dev->setup_can_stall = 0;
1499 goto delegate;
1500 }
1501 }
1502 break;
1503
1504#ifndef CONFIG_USB_GADGET_PXA25X
1505 /* PXA automagically handles this request too */
1506 case USB_REQ_GET_CONFIGURATION:
1507 if (ctrl->bRequestType != 0x80)
1508 goto unrecognized;
1509 *(u8 *)req->buf = dev->current_config;
1510 value = min (w_length, (u16) 1);
1511 break;
1512#endif
1513
1514 default:
1515unrecognized:
1516 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1517 dev->usermode_setup ? "delegate" : "fail",
1518 ctrl->bRequestType, ctrl->bRequest,
1519 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1520
1521 /* if there's an ep0 reader, don't stall */
1522 if (dev->usermode_setup) {
1523 dev->setup_can_stall = 1;
1524delegate:
1525 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1526 ? 1 : 0;
1527 dev->setup_wLength = w_length;
1528 dev->setup_out_ready = 0;
1529 dev->setup_out_error = 0;
1530 value = 0;
1531
1532 /* read DATA stage for OUT right away */
1533 if (unlikely (!dev->setup_in && w_length)) {
1534 value = setup_req (gadget->ep0, dev->req,
1535 w_length);
1536 if (value < 0)
1537 break;
1538 value = usb_ep_queue (gadget->ep0, dev->req,
1539 GFP_ATOMIC);
1540 if (value < 0) {
1541 clean_req (gadget->ep0, dev->req);
1542 break;
1543 }
1544
1545 /* we can't currently stall these */
1546 dev->setup_can_stall = 0;
1547 }
1548
1549 /* state changes when reader collects event */
1550 event = next_event (dev, GADGETFS_SETUP);
1551 event->u.setup = *ctrl;
1552 ep0_readable (dev);
1553 spin_unlock (&dev->lock);
1554 return 0;
1555 }
1556 }
1557
1558 /* proceed with data transfer and status phases? */
1559 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1560 req->length = value;
1561 req->zero = value < w_length;
1562 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1563 if (value < 0) {
1564 DBG (dev, "ep_queue --> %d\n", value);
1565 req->status = 0;
1566 }
1567 }
1568
1569 /* device stalls when value < 0 */
1570 spin_unlock (&dev->lock);
1571 return value;
1572}
1573
1574static void destroy_ep_files (struct dev_data *dev)
1575{
1576 DBG (dev, "%s %d\n", __func__, dev->state);
1577
1578 /* dev->state must prevent interference */
1579 spin_lock_irq (&dev->lock);
1580 while (!list_empty(&dev->epfiles)) {
1581 struct ep_data *ep;
1582 struct inode *parent;
1583 struct dentry *dentry;
1584
1585 /* break link to FS */
1586 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1587 list_del_init (&ep->epfiles);
1588 dentry = ep->dentry;
1589 ep->dentry = NULL;
1590 parent = dentry->d_parent->d_inode;
1591
1592 /* break link to controller */
1593 if (ep->state == STATE_EP_ENABLED)
1594 (void) usb_ep_disable (ep->ep);
1595 ep->state = STATE_EP_UNBOUND;
1596 usb_ep_free_request (ep->ep, ep->req);
1597 ep->ep = NULL;
1598 wake_up (&ep->wait);
1599 put_ep (ep);
1600
1601 spin_unlock_irq (&dev->lock);
1602
1603 /* break link to dcache */
1604 mutex_lock (&parent->i_mutex);
1605 d_delete (dentry);
1606 dput (dentry);
1607 mutex_unlock (&parent->i_mutex);
1608
1609 spin_lock_irq (&dev->lock);
1610 }
1611 spin_unlock_irq (&dev->lock);
1612}
1613
1614
1615static struct inode *
1616gadgetfs_create_file (struct super_block *sb, char const *name,
1617 void *data, const struct file_operations *fops,
1618 struct dentry **dentry_p);
1619
1620static int activate_ep_files (struct dev_data *dev)
1621{
1622 struct usb_ep *ep;
1623 struct ep_data *data;
1624
1625 gadget_for_each_ep (ep, dev->gadget) {
1626
1627 data = kzalloc(sizeof(*data), GFP_KERNEL);
1628 if (!data)
1629 goto enomem0;
1630 data->state = STATE_EP_DISABLED;
1631 mutex_init(&data->lock);
1632 init_waitqueue_head (&data->wait);
1633
1634 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1635 atomic_set (&data->count, 1);
1636 data->dev = dev;
1637 get_dev (dev);
1638
1639 data->ep = ep;
1640 ep->driver_data = data;
1641
1642 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1643 if (!data->req)
1644 goto enomem1;
1645
1646 data->inode = gadgetfs_create_file (dev->sb, data->name,
1647 data, &ep_config_operations,
1648 &data->dentry);
1649 if (!data->inode)
1650 goto enomem2;
1651 list_add_tail (&data->epfiles, &dev->epfiles);
1652 }
1653 return 0;
1654
1655enomem2:
1656 usb_ep_free_request (ep, data->req);
1657enomem1:
1658 put_dev (dev);
1659 kfree (data);
1660enomem0:
1661 DBG (dev, "%s enomem\n", __func__);
1662 destroy_ep_files (dev);
1663 return -ENOMEM;
1664}
1665
1666static void
1667gadgetfs_unbind (struct usb_gadget *gadget)
1668{
1669 struct dev_data *dev = get_gadget_data (gadget);
1670
1671 DBG (dev, "%s\n", __func__);
1672
1673 spin_lock_irq (&dev->lock);
1674 dev->state = STATE_DEV_UNBOUND;
1675 spin_unlock_irq (&dev->lock);
1676
1677 destroy_ep_files (dev);
1678 gadget->ep0->driver_data = NULL;
1679 set_gadget_data (gadget, NULL);
1680
1681 /* we've already been disconnected ... no i/o is active */
1682 if (dev->req)
1683 usb_ep_free_request (gadget->ep0, dev->req);
1684 DBG (dev, "%s done\n", __func__);
1685 put_dev (dev);
1686}
1687
1688static struct dev_data *the_device;
1689
1690static int gadgetfs_bind(struct usb_gadget *gadget,
1691 struct usb_gadget_driver *driver)
1692{
1693 struct dev_data *dev = the_device;
1694
1695 if (!dev)
1696 return -ESRCH;
1697 if (0 != strcmp (CHIP, gadget->name)) {
1698 pr_err("%s expected %s controller not %s\n",
1699 shortname, CHIP, gadget->name);
1700 return -ENODEV;
1701 }
1702
1703 set_gadget_data (gadget, dev);
1704 dev->gadget = gadget;
1705 gadget->ep0->driver_data = dev;
1706
1707 /* preallocate control response and buffer */
1708 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1709 if (!dev->req)
1710 goto enomem;
1711 dev->req->context = NULL;
1712 dev->req->complete = epio_complete;
1713
1714 if (activate_ep_files (dev) < 0)
1715 goto enomem;
1716
1717 INFO (dev, "bound to %s driver\n", gadget->name);
1718 spin_lock_irq(&dev->lock);
1719 dev->state = STATE_DEV_UNCONNECTED;
1720 spin_unlock_irq(&dev->lock);
1721 get_dev (dev);
1722 return 0;
1723
1724enomem:
1725 gadgetfs_unbind (gadget);
1726 return -ENOMEM;
1727}
1728
1729static void
1730gadgetfs_disconnect (struct usb_gadget *gadget)
1731{
1732 struct dev_data *dev = get_gadget_data (gadget);
1733 unsigned long flags;
1734
1735 spin_lock_irqsave (&dev->lock, flags);
1736 if (dev->state == STATE_DEV_UNCONNECTED)
1737 goto exit;
1738 dev->state = STATE_DEV_UNCONNECTED;
1739
1740 INFO (dev, "disconnected\n");
1741 next_event (dev, GADGETFS_DISCONNECT);
1742 ep0_readable (dev);
1743exit:
1744 spin_unlock_irqrestore (&dev->lock, flags);
1745}
1746
1747static void
1748gadgetfs_suspend (struct usb_gadget *gadget)
1749{
1750 struct dev_data *dev = get_gadget_data (gadget);
1751
1752 INFO (dev, "suspended from state %d\n", dev->state);
1753 spin_lock (&dev->lock);
1754 switch (dev->state) {
1755 case STATE_DEV_SETUP: // VERY odd... host died??
1756 case STATE_DEV_CONNECTED:
1757 case STATE_DEV_UNCONNECTED:
1758 next_event (dev, GADGETFS_SUSPEND);
1759 ep0_readable (dev);
1760 /* FALLTHROUGH */
1761 default:
1762 break;
1763 }
1764 spin_unlock (&dev->lock);
1765}
1766
1767static struct usb_gadget_driver gadgetfs_driver = {
1768 .function = (char *) driver_desc,
1769 .bind = gadgetfs_bind,
1770 .unbind = gadgetfs_unbind,
1771 .setup = gadgetfs_setup,
1772 .disconnect = gadgetfs_disconnect,
1773 .suspend = gadgetfs_suspend,
1774
1775 .driver = {
1776 .name = (char *) shortname,
1777 },
1778};
1779
1780/*----------------------------------------------------------------------*/
1781
1782static void gadgetfs_nop(struct usb_gadget *arg) { }
1783
1784static int gadgetfs_probe(struct usb_gadget *gadget,
1785 struct usb_gadget_driver *driver)
1786{
1787 CHIP = gadget->name;
1788 return -EISNAM;
1789}
1790
1791static struct usb_gadget_driver probe_driver = {
1792 .max_speed = USB_SPEED_HIGH,
1793 .bind = gadgetfs_probe,
1794 .unbind = gadgetfs_nop,
1795 .setup = (void *)gadgetfs_nop,
1796 .disconnect = gadgetfs_nop,
1797 .driver = {
1798 .name = "nop",
1799 },
1800};
1801
1802
1803/* DEVICE INITIALIZATION
1804 *
1805 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1806 * status = write (fd, descriptors, sizeof descriptors)
1807 *
1808 * That write establishes the device configuration, so the kernel can
1809 * bind to the controller ... guaranteeing it can handle enumeration
1810 * at all necessary speeds. Descriptor order is:
1811 *
1812 * . message tag (u32, host order) ... for now, must be zero; it
1813 * would change to support features like multi-config devices
1814 * . full/low speed config ... all wTotalLength bytes (with interface,
1815 * class, altsetting, endpoint, and other descriptors)
1816 * . high speed config ... all descriptors, for high speed operation;
1817 * this one's optional except for high-speed hardware
1818 * . device descriptor
1819 *
1820 * Endpoints are not yet enabled. Drivers must wait until device
1821 * configuration and interface altsetting changes create
1822 * the need to configure (or unconfigure) them.
1823 *
1824 * After initialization, the device stays active for as long as that
1825 * $CHIP file is open. Events must then be read from that descriptor,
1826 * such as configuration notifications.
1827 */
1828
1829static int is_valid_config (struct usb_config_descriptor *config)
1830{
1831 return config->bDescriptorType == USB_DT_CONFIG
1832 && config->bLength == USB_DT_CONFIG_SIZE
1833 && config->bConfigurationValue != 0
1834 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1835 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1836 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1837 /* FIXME check lengths: walk to end */
1838}
1839
1840static ssize_t
1841dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1842{
1843 struct dev_data *dev = fd->private_data;
1844 ssize_t value = len, length = len;
1845 unsigned total;
1846 u32 tag;
1847 char *kbuf;
1848
1849 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1850 return -EINVAL;
1851
1852 /* we might need to change message format someday */
1853 if (copy_from_user (&tag, buf, 4))
1854 return -EFAULT;
1855 if (tag != 0)
1856 return -EINVAL;
1857 buf += 4;
1858 length -= 4;
1859
1860 kbuf = memdup_user(buf, length);
1861 if (IS_ERR(kbuf))
1862 return PTR_ERR(kbuf);
1863
1864 spin_lock_irq (&dev->lock);
1865 value = -EINVAL;
1866 if (dev->buf)
1867 goto fail;
1868 dev->buf = kbuf;
1869
1870 /* full or low speed config */
1871 dev->config = (void *) kbuf;
1872 total = le16_to_cpu(dev->config->wTotalLength);
1873 if (!is_valid_config (dev->config) || total >= length)
1874 goto fail;
1875 kbuf += total;
1876 length -= total;
1877
1878 /* optional high speed config */
1879 if (kbuf [1] == USB_DT_CONFIG) {
1880 dev->hs_config = (void *) kbuf;
1881 total = le16_to_cpu(dev->hs_config->wTotalLength);
1882 if (!is_valid_config (dev->hs_config) || total >= length)
1883 goto fail;
1884 kbuf += total;
1885 length -= total;
1886 }
1887
1888 /* could support multiple configs, using another encoding! */
1889
1890 /* device descriptor (tweaked for paranoia) */
1891 if (length != USB_DT_DEVICE_SIZE)
1892 goto fail;
1893 dev->dev = (void *)kbuf;
1894 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1895 || dev->dev->bDescriptorType != USB_DT_DEVICE
1896 || dev->dev->bNumConfigurations != 1)
1897 goto fail;
1898 dev->dev->bNumConfigurations = 1;
1899 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1900
1901 /* triggers gadgetfs_bind(); then we can enumerate. */
1902 spin_unlock_irq (&dev->lock);
1903 if (dev->hs_config)
1904 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1905 else
1906 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1907
1908 value = usb_gadget_probe_driver(&gadgetfs_driver);
1909 if (value != 0) {
1910 kfree (dev->buf);
1911 dev->buf = NULL;
1912 } else {
1913 /* at this point "good" hardware has for the first time
1914 * let the USB the host see us. alternatively, if users
1915 * unplug/replug that will clear all the error state.
1916 *
1917 * note: everything running before here was guaranteed
1918 * to choke driver model style diagnostics. from here
1919 * on, they can work ... except in cleanup paths that
1920 * kick in after the ep0 descriptor is closed.
1921 */
1922 fd->f_op = &ep0_io_operations;
1923 value = len;
1924 }
1925 return value;
1926
1927fail:
1928 spin_unlock_irq (&dev->lock);
1929 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1930 kfree (dev->buf);
1931 dev->buf = NULL;
1932 return value;
1933}
1934
1935static int
1936dev_open (struct inode *inode, struct file *fd)
1937{
1938 struct dev_data *dev = inode->i_private;
1939 int value = -EBUSY;
1940
1941 spin_lock_irq(&dev->lock);
1942 if (dev->state == STATE_DEV_DISABLED) {
1943 dev->ev_next = 0;
1944 dev->state = STATE_DEV_OPENED;
1945 fd->private_data = dev;
1946 get_dev (dev);
1947 value = 0;
1948 }
1949 spin_unlock_irq(&dev->lock);
1950 return value;
1951}
1952
1953static const struct file_operations dev_init_operations = {
1954 .llseek = no_llseek,
1955
1956 .open = dev_open,
1957 .write = dev_config,
1958 .fasync = ep0_fasync,
1959 .unlocked_ioctl = dev_ioctl,
1960 .release = dev_release,
1961};
1962
1963/*----------------------------------------------------------------------*/
1964
1965/* FILESYSTEM AND SUPERBLOCK OPERATIONS
1966 *
1967 * Mounting the filesystem creates a controller file, used first for
1968 * device configuration then later for event monitoring.
1969 */
1970
1971
1972/* FIXME PAM etc could set this security policy without mount options
1973 * if epfiles inherited ownership and permissons from ep0 ...
1974 */
1975
1976static unsigned default_uid;
1977static unsigned default_gid;
1978static unsigned default_perm = S_IRUSR | S_IWUSR;
1979
1980module_param (default_uid, uint, 0644);
1981module_param (default_gid, uint, 0644);
1982module_param (default_perm, uint, 0644);
1983
1984
1985static struct inode *
1986gadgetfs_make_inode (struct super_block *sb,
1987 void *data, const struct file_operations *fops,
1988 int mode)
1989{
1990 struct inode *inode = new_inode (sb);
1991
1992 if (inode) {
1993 inode->i_ino = get_next_ino();
1994 inode->i_mode = mode;
1995 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1996 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1997 inode->i_atime = inode->i_mtime = inode->i_ctime
1998 = CURRENT_TIME;
1999 inode->i_private = data;
2000 inode->i_fop = fops;
2001 }
2002 return inode;
2003}
2004
2005/* creates in fs root directory, so non-renamable and non-linkable.
2006 * so inode and dentry are paired, until device reconfig.
2007 */
2008static struct inode *
2009gadgetfs_create_file (struct super_block *sb, char const *name,
2010 void *data, const struct file_operations *fops,
2011 struct dentry **dentry_p)
2012{
2013 struct dentry *dentry;
2014 struct inode *inode;
2015
2016 dentry = d_alloc_name(sb->s_root, name);
2017 if (!dentry)
2018 return NULL;
2019
2020 inode = gadgetfs_make_inode (sb, data, fops,
2021 S_IFREG | (default_perm & S_IRWXUGO));
2022 if (!inode) {
2023 dput(dentry);
2024 return NULL;
2025 }
2026 d_add (dentry, inode);
2027 *dentry_p = dentry;
2028 return inode;
2029}
2030
2031static const struct super_operations gadget_fs_operations = {
2032 .statfs = simple_statfs,
2033 .drop_inode = generic_delete_inode,
2034};
2035
2036static int
2037gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2038{
2039 struct inode *inode;
2040 struct dev_data *dev;
2041
2042 if (the_device)
2043 return -ESRCH;
2044
2045 /* fake probe to determine $CHIP */
2046 CHIP = NULL;
2047 usb_gadget_probe_driver(&probe_driver);
2048 if (!CHIP)
2049 return -ENODEV;
2050
2051 /* superblock */
2052 sb->s_blocksize = PAGE_CACHE_SIZE;
2053 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2054 sb->s_magic = GADGETFS_MAGIC;
2055 sb->s_op = &gadget_fs_operations;
2056 sb->s_time_gran = 1;
2057
2058 /* root inode */
2059 inode = gadgetfs_make_inode (sb,
2060 NULL, &simple_dir_operations,
2061 S_IFDIR | S_IRUGO | S_IXUGO);
2062 if (!inode)
2063 goto Enomem;
2064 inode->i_op = &simple_dir_inode_operations;
2065 if (!(sb->s_root = d_make_root (inode)))
2066 goto Enomem;
2067
2068 /* the ep0 file is named after the controller we expect;
2069 * user mode code can use it for sanity checks, like we do.
2070 */
2071 dev = dev_new ();
2072 if (!dev)
2073 goto Enomem;
2074
2075 dev->sb = sb;
2076 if (!gadgetfs_create_file (sb, CHIP,
2077 dev, &dev_init_operations,
2078 &dev->dentry)) {
2079 put_dev(dev);
2080 goto Enomem;
2081 }
2082
2083 /* other endpoint files are available after hardware setup,
2084 * from binding to a controller.
2085 */
2086 the_device = dev;
2087 return 0;
2088
2089Enomem:
2090 return -ENOMEM;
2091}
2092
2093/* "mount -t gadgetfs path /dev/gadget" ends up here */
2094static struct dentry *
2095gadgetfs_mount (struct file_system_type *t, int flags,
2096 const char *path, void *opts)
2097{
2098 return mount_single (t, flags, opts, gadgetfs_fill_super);
2099}
2100
2101static void
2102gadgetfs_kill_sb (struct super_block *sb)
2103{
2104 kill_litter_super (sb);
2105 if (the_device) {
2106 put_dev (the_device);
2107 the_device = NULL;
2108 }
2109}
2110
2111/*----------------------------------------------------------------------*/
2112
2113static struct file_system_type gadgetfs_type = {
2114 .owner = THIS_MODULE,
2115 .name = shortname,
2116 .mount = gadgetfs_mount,
2117 .kill_sb = gadgetfs_kill_sb,
2118};
2119MODULE_ALIAS_FS("gadgetfs");
2120
2121/*----------------------------------------------------------------------*/
2122
2123static int __init init (void)
2124{
2125 int status;
2126
2127 status = register_filesystem (&gadgetfs_type);
2128 if (status == 0)
2129 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2130 shortname, driver_desc);
2131 return status;
2132}
2133module_init (init);
2134
2135static void __exit cleanup (void)
2136{
2137 pr_debug ("unregister %s\n", shortname);
2138 unregister_filesystem (&gadgetfs_type);
2139}
2140module_exit (cleanup);
2141