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[S390] Remove error checking from copy_oldmem_page()
[linux/fpc-iii.git] / drivers / usb / gadget / inode.c
bloba392ec0d2d5179beebf3923dc6b275001b4961c5
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
28 #include <linux/device.h>
29 #include <linux/moduleparam.h>
30
31 #include <linux/usb/gadgetfs.h>
32 #include <linux/usb/gadget.h>
33
34
35 /*
36 * The gadgetfs API maps each endpoint to a file descriptor so that you
37 * can use standard synchronous read/write calls for I/O. There's some
38 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
39 * drivers show how this works in practice. You can also use AIO to
40 * eliminate I/O gaps between requests, to help when streaming data.
41 *
42 * Key parts that must be USB-specific are protocols defining how the
43 * read/write operations relate to the hardware state machines. There
44 * are two types of files. One type is for the device, implementing ep0.
45 * The other type is for each IN or OUT endpoint. In both cases, the
46 * user mode driver must configure the hardware before using it.
47 *
48 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
49 * (by writing configuration and device descriptors). Afterwards it
50 * may serve as a source of device events, used to handle all control
51 * requests other than basic enumeration.
52 *
53 * - Then, after a SET_CONFIGURATION control request, ep_config() is
54 * called when each /dev/gadget/ep* file is configured (by writing
55 * endpoint descriptors). Afterwards these files are used to write()
56 * IN data or to read() OUT data. To halt the endpoint, a "wrong
57 * direction" request is issued (like reading an IN endpoint).
58 *
59 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
60 * not possible on all hardware. For example, precise fault handling with
61 * respect to data left in endpoint fifos after aborted operations; or
62 * selective clearing of endpoint halts, to implement SET_INTERFACE.
63 */
64
65 #define DRIVER_DESC "USB Gadget filesystem"
66 #define DRIVER_VERSION "24 Aug 2004"
67
68 static const char driver_desc [] = DRIVER_DESC;
69 static const char shortname [] = "gadgetfs";
70
71 MODULE_DESCRIPTION (DRIVER_DESC);
72 MODULE_AUTHOR ("David Brownell");
73 MODULE_LICENSE ("GPL");
74
75
76 /*----------------------------------------------------------------------*/
77
78 #define GADGETFS_MAGIC 0xaee71ee7
79 #define DMA_ADDR_INVALID (~(dma_addr_t)0)
80
81 /* /dev/gadget/$CHIP represents ep0 and the whole device */
82 enum ep0_state {
83 /* DISBLED is the initial state.
84 */
85 STATE_DEV_DISABLED = 0,
86
87 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
88 * ep0/device i/o modes and binding to the controller. Driver
89 * must always write descriptors to initialize the device, then
90 * the device becomes UNCONNECTED until enumeration.
91 */
92 STATE_DEV_OPENED,
93
94 /* From then on, ep0 fd is in either of two basic modes:
95 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
96 * - SETUP: read/write will transfer control data and succeed;
97 * or if "wrong direction", performs protocol stall
98 */
99 STATE_DEV_UNCONNECTED,
100 STATE_DEV_CONNECTED,
101 STATE_DEV_SETUP,
102
103 /* UNBOUND means the driver closed ep0, so the device won't be
104 * accessible again (DEV_DISABLED) until all fds are closed.
105 */
106 STATE_DEV_UNBOUND,
107 };
108
109 /* enough for the whole queue: most events invalidate others */
110 #define N_EVENT 5
111
112 struct dev_data {
113 spinlock_t lock;
114 atomic_t count;
115 enum ep0_state state; /* P: lock */
116 struct usb_gadgetfs_event event [N_EVENT];
117 unsigned ev_next;
118 struct fasync_struct *fasync;
119 u8 current_config;
120
121 /* drivers reading ep0 MUST handle control requests (SETUP)
122 * reported that way; else the host will time out.
123 */
124 unsigned usermode_setup : 1,
125 setup_in : 1,
126 setup_can_stall : 1,
127 setup_out_ready : 1,
128 setup_out_error : 1,
129 setup_abort : 1;
130 unsigned setup_wLength;
131
132 /* the rest is basically write-once */
133 struct usb_config_descriptor *config, *hs_config;
134 struct usb_device_descriptor *dev;
135 struct usb_request *req;
136 struct usb_gadget *gadget;
137 struct list_head epfiles;
138 void *buf;
139 wait_queue_head_t wait;
140 struct super_block *sb;
141 struct dentry *dentry;
142
143 /* except this scratch i/o buffer for ep0 */
144 u8 rbuf [256];
145 };
146
147 static inline void get_dev (struct dev_data *data)
148 {
149 atomic_inc (&data->count);
150 }
151
152 static void put_dev (struct dev_data *data)
153 {
154 if (likely (!atomic_dec_and_test (&data->count)))
155 return;
156 /* needs no more cleanup */
157 BUG_ON (waitqueue_active (&data->wait));
158 kfree (data);
159 }
160
161 static struct dev_data *dev_new (void)
162 {
163 struct dev_data *dev;
164
165 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
166 if (!dev)
167 return NULL;
168 dev->state = STATE_DEV_DISABLED;
169 atomic_set (&dev->count, 1);
170 spin_lock_init (&dev->lock);
171 INIT_LIST_HEAD (&dev->epfiles);
172 init_waitqueue_head (&dev->wait);
173 return dev;
174 }
175
176 /*----------------------------------------------------------------------*/
177
178 /* other /dev/gadget/$ENDPOINT files represent endpoints */
179 enum ep_state {
180 STATE_EP_DISABLED = 0,
181 STATE_EP_READY,
182 STATE_EP_ENABLED,
183 STATE_EP_UNBOUND,
184 };
185
186 struct ep_data {
187 struct mutex lock;
188 enum ep_state state;
189 atomic_t count;
190 struct dev_data *dev;
191 /* must hold dev->lock before accessing ep or req */
192 struct usb_ep *ep;
193 struct usb_request *req;
194 ssize_t status;
195 char name [16];
196 struct usb_endpoint_descriptor desc, hs_desc;
197 struct list_head epfiles;
198 wait_queue_head_t wait;
199 struct dentry *dentry;
200 struct inode *inode;
201 };
202
203 static inline void get_ep (struct ep_data *data)
204 {
205 atomic_inc (&data->count);
206 }
207
208 static void put_ep (struct ep_data *data)
209 {
210 if (likely (!atomic_dec_and_test (&data->count)))
211 return;
212 put_dev (data->dev);
213 /* needs no more cleanup */
214 BUG_ON (!list_empty (&data->epfiles));
215 BUG_ON (waitqueue_active (&data->wait));
216 kfree (data);
217 }
218
219 /*----------------------------------------------------------------------*/
220
221 /* most "how to use the hardware" policy choices are in userspace:
222 * mapping endpoint roles (which the driver needs) to the capabilities
223 * which the usb controller has. most of those capabilities are exposed
224 * implicitly, starting with the driver name and then endpoint names.
225 */
226
227 static const char *CHIP;
228
229 /*----------------------------------------------------------------------*/
230
231 /* NOTE: don't use dev_printk calls before binding to the gadget
232 * at the end of ep0 configuration, or after unbind.
233 */
234
235 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
236 #define xprintk(d,level,fmt,args...) \
237 printk(level "%s: " fmt , shortname , ## args)
238
239 #ifdef DEBUG
240 #define DBG(dev,fmt,args...) \
241 xprintk(dev , KERN_DEBUG , fmt , ## args)
242 #else
243 #define DBG(dev,fmt,args...) \
244 do { } while (0)
245 #endif /* DEBUG */
246
247 #ifdef VERBOSE_DEBUG
248 #define VDEBUG DBG
249 #else
250 #define VDEBUG(dev,fmt,args...) \
251 do { } while (0)
252 #endif /* DEBUG */
253
254 #define ERROR(dev,fmt,args...) \
255 xprintk(dev , KERN_ERR , fmt , ## args)
256 #define INFO(dev,fmt,args...) \
257 xprintk(dev , KERN_INFO , fmt , ## args)
258
259
260 /*----------------------------------------------------------------------*/
261
262 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
263 *
264 * After opening, configure non-control endpoints. Then use normal
265 * stream read() and write() requests; and maybe ioctl() to get more
266 * precise FIFO status when recovering from cancellation.
267 */
268
269 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
270 {
271 struct ep_data *epdata = ep->driver_data;
272
273 if (!req->context)
274 return;
275 if (req->status)
276 epdata->status = req->status;
277 else
278 epdata->status = req->actual;
279 complete ((struct completion *)req->context);
280 }
281
282 /* tasklock endpoint, returning when it's connected.
283 * still need dev->lock to use epdata->ep.
284 */
285 static int
286 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
287 {
288 int val;
289
290 if (f_flags & O_NONBLOCK) {
291 if (!mutex_trylock(&epdata->lock))
292 goto nonblock;
293 if (epdata->state != STATE_EP_ENABLED) {
294 mutex_unlock(&epdata->lock);
295 nonblock:
296 val = -EAGAIN;
297 } else
298 val = 0;
299 return val;
300 }
301
302 val = mutex_lock_interruptible(&epdata->lock);
303 if (val < 0)
304 return val;
305
306 switch (epdata->state) {
307 case STATE_EP_ENABLED:
308 break;
309 // case STATE_EP_DISABLED: /* "can't happen" */
310 // case STATE_EP_READY: /* "can't happen" */
311 default: /* error! */
312 pr_debug ("%s: ep %p not available, state %d\n",
313 shortname, epdata, epdata->state);
314 // FALLTHROUGH
315 case STATE_EP_UNBOUND: /* clean disconnect */
316 val = -ENODEV;
317 mutex_unlock(&epdata->lock);
318 }
319 return val;
320 }
321
322 static ssize_t
323 ep_io (struct ep_data *epdata, void *buf, unsigned len)
324 {
325 DECLARE_COMPLETION_ONSTACK (done);
326 int value;
327
328 spin_lock_irq (&epdata->dev->lock);
329 if (likely (epdata->ep != NULL)) {
330 struct usb_request *req = epdata->req;
331
332 req->context = &done;
333 req->complete = epio_complete;
334 req->buf = buf;
335 req->length = len;
336 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
337 } else
338 value = -ENODEV;
339 spin_unlock_irq (&epdata->dev->lock);
340
341 if (likely (value == 0)) {
342 value = wait_event_interruptible (done.wait, done.done);
343 if (value != 0) {
344 spin_lock_irq (&epdata->dev->lock);
345 if (likely (epdata->ep != NULL)) {
346 DBG (epdata->dev, "%s i/o interrupted\n",
347 epdata->name);
348 usb_ep_dequeue (epdata->ep, epdata->req);
349 spin_unlock_irq (&epdata->dev->lock);
350
351 wait_event (done.wait, done.done);
352 if (epdata->status == -ECONNRESET)
353 epdata->status = -EINTR;
354 } else {
355 spin_unlock_irq (&epdata->dev->lock);
356
357 DBG (epdata->dev, "endpoint gone\n");
358 epdata->status = -ENODEV;
359 }
360 }
361 return epdata->status;
362 }
363 return value;
364 }
365
366
367 /* handle a synchronous OUT bulk/intr/iso transfer */
368 static ssize_t
369 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
370 {
371 struct ep_data *data = fd->private_data;
372 void *kbuf;
373 ssize_t value;
374
375 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
376 return value;
377
378 /* halt any endpoint by doing a "wrong direction" i/o call */
379 if (usb_endpoint_dir_in(&data->desc)) {
380 if (usb_endpoint_xfer_isoc(&data->desc)) {
381 mutex_unlock(&data->lock);
382 return -EINVAL;
383 }
384 DBG (data->dev, "%s halt\n", data->name);
385 spin_lock_irq (&data->dev->lock);
386 if (likely (data->ep != NULL))
387 usb_ep_set_halt (data->ep);
388 spin_unlock_irq (&data->dev->lock);
389 mutex_unlock(&data->lock);
390 return -EBADMSG;
391 }
392
393 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
394
395 value = -ENOMEM;
396 kbuf = kmalloc (len, GFP_KERNEL);
397 if (unlikely (!kbuf))
398 goto free1;
399
400 value = ep_io (data, kbuf, len);
401 VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
402 data->name, len, (int) value);
403 if (value >= 0 && copy_to_user (buf, kbuf, value))
404 value = -EFAULT;
405
406 free1:
407 mutex_unlock(&data->lock);
408 kfree (kbuf);
409 return value;
410 }
411
412 /* handle a synchronous IN bulk/intr/iso transfer */
413 static ssize_t
414 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
415 {
416 struct ep_data *data = fd->private_data;
417 void *kbuf;
418 ssize_t value;
419
420 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
421 return value;
422
423 /* halt any endpoint by doing a "wrong direction" i/o call */
424 if (!usb_endpoint_dir_in(&data->desc)) {
425 if (usb_endpoint_xfer_isoc(&data->desc)) {
426 mutex_unlock(&data->lock);
427 return -EINVAL;
428 }
429 DBG (data->dev, "%s halt\n", data->name);
430 spin_lock_irq (&data->dev->lock);
431 if (likely (data->ep != NULL))
432 usb_ep_set_halt (data->ep);
433 spin_unlock_irq (&data->dev->lock);
434 mutex_unlock(&data->lock);
435 return -EBADMSG;
436 }
437
438 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
439
440 value = -ENOMEM;
441 kbuf = kmalloc (len, GFP_KERNEL);
442 if (!kbuf)
443 goto free1;
444 if (copy_from_user (kbuf, buf, len)) {
445 value = -EFAULT;
446 goto free1;
447 }
448
449 value = ep_io (data, kbuf, len);
450 VDEBUG (data->dev, "%s write %zu IN, status %d\n",
451 data->name, len, (int) value);
452 free1:
453 mutex_unlock(&data->lock);
454 kfree (kbuf);
455 return value;
456 }
457
458 static int
459 ep_release (struct inode *inode, struct file *fd)
460 {
461 struct ep_data *data = fd->private_data;
462 int value;
463
464 value = mutex_lock_interruptible(&data->lock);
465 if (value < 0)
466 return value;
467
468 /* clean up if this can be reopened */
469 if (data->state != STATE_EP_UNBOUND) {
470 data->state = STATE_EP_DISABLED;
471 data->desc.bDescriptorType = 0;
472 data->hs_desc.bDescriptorType = 0;
473 usb_ep_disable(data->ep);
474 }
475 mutex_unlock(&data->lock);
476 put_ep (data);
477 return 0;
478 }
479
480 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
481 {
482 struct ep_data *data = fd->private_data;
483 int status;
484
485 if ((status = get_ready_ep (fd->f_flags, data)) < 0)
486 return status;
487
488 spin_lock_irq (&data->dev->lock);
489 if (likely (data->ep != NULL)) {
490 switch (code) {
491 case GADGETFS_FIFO_STATUS:
492 status = usb_ep_fifo_status (data->ep);
493 break;
494 case GADGETFS_FIFO_FLUSH:
495 usb_ep_fifo_flush (data->ep);
496 break;
497 case GADGETFS_CLEAR_HALT:
498 status = usb_ep_clear_halt (data->ep);
499 break;
500 default:
501 status = -ENOTTY;
502 }
503 } else
504 status = -ENODEV;
505 spin_unlock_irq (&data->dev->lock);
506 mutex_unlock(&data->lock);
507 return status;
508 }
509
510 /*----------------------------------------------------------------------*/
511
512 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
513
514 struct kiocb_priv {
515 struct usb_request *req;
516 struct ep_data *epdata;
517 void *buf;
518 const struct iovec *iv;
519 unsigned long nr_segs;
520 unsigned actual;
521 };
522
523 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
524 {
525 struct kiocb_priv *priv = iocb->private;
526 struct ep_data *epdata;
527 int value;
528
529 local_irq_disable();
530 epdata = priv->epdata;
531 // spin_lock(&epdata->dev->lock);
532 kiocbSetCancelled(iocb);
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 aio_put_req(iocb);
541 return value;
542 }
543
544 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
545 {
546 struct kiocb_priv *priv = iocb->private;
547 ssize_t len, total;
548 void *to_copy;
549 int i;
550
551 /* we "retry" to get the right mm context for this: */
552
553 /* copy stuff into user buffers */
554 total = priv->actual;
555 len = 0;
556 to_copy = priv->buf;
557 for (i=0; i < priv->nr_segs; i++) {
558 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
559
560 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
561 if (len == 0)
562 len = -EFAULT;
563 break;
564 }
565
566 total -= this;
567 len += this;
568 to_copy += this;
569 if (total == 0)
570 break;
571 }
572 kfree(priv->buf);
573 kfree(priv);
574 return len;
575 }
576
577 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
578 {
579 struct kiocb *iocb = req->context;
580 struct kiocb_priv *priv = iocb->private;
581 struct ep_data *epdata = priv->epdata;
582
583 /* lock against disconnect (and ideally, cancel) */
584 spin_lock(&epdata->dev->lock);
585 priv->req = NULL;
586 priv->epdata = NULL;
587
588 /* if this was a write or a read returning no data then we
589 * don't need to copy anything to userspace, so we can
590 * complete the aio request immediately.
591 */
592 if (priv->iv == NULL || unlikely(req->actual == 0)) {
593 kfree(req->buf);
594 kfree(priv);
595 iocb->private = NULL;
596 /* aio_complete() reports bytes-transferred _and_ faults */
597 aio_complete(iocb, req->actual ? req->actual : req->status,
598 req->status);
599 } else {
600 /* retry() won't report both; so we hide some faults */
601 if (unlikely(0 != req->status))
602 DBG(epdata->dev, "%s fault %d len %d\n",
603 ep->name, req->status, req->actual);
604
605 priv->buf = req->buf;
606 priv->actual = req->actual;
607 kick_iocb(iocb);
608 }
609 spin_unlock(&epdata->dev->lock);
610
611 usb_ep_free_request(ep, req);
612 put_ep(epdata);
613 }
614
615 static ssize_t
616 ep_aio_rwtail(
617 struct kiocb *iocb,
618 char *buf,
619 size_t len,
620 struct ep_data *epdata,
621 const struct iovec *iv,
622 unsigned long nr_segs
623 )
624 {
625 struct kiocb_priv *priv;
626 struct usb_request *req;
627 ssize_t value;
628
629 priv = kmalloc(sizeof *priv, GFP_KERNEL);
630 if (!priv) {
631 value = -ENOMEM;
632 fail:
633 kfree(buf);
634 return value;
635 }
636 iocb->private = priv;
637 priv->iv = iv;
638 priv->nr_segs = nr_segs;
639
640 value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
641 if (unlikely(value < 0)) {
642 kfree(priv);
643 goto fail;
644 }
645
646 iocb->ki_cancel = ep_aio_cancel;
647 get_ep(epdata);
648 priv->epdata = epdata;
649 priv->actual = 0;
650
651 /* each kiocb is coupled to one usb_request, but we can't
652 * allocate or submit those if the host disconnected.
653 */
654 spin_lock_irq(&epdata->dev->lock);
655 if (likely(epdata->ep)) {
656 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
657 if (likely(req)) {
658 priv->req = req;
659 req->buf = buf;
660 req->length = len;
661 req->complete = ep_aio_complete;
662 req->context = iocb;
663 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
664 if (unlikely(0 != value))
665 usb_ep_free_request(epdata->ep, req);
666 } else
667 value = -EAGAIN;
668 } else
669 value = -ENODEV;
670 spin_unlock_irq(&epdata->dev->lock);
671
672 mutex_unlock(&epdata->lock);
673
674 if (unlikely(value)) {
675 kfree(priv);
676 put_ep(epdata);
677 } else
678 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
679 return value;
680 }
681
682 static ssize_t
683 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
684 unsigned long nr_segs, loff_t o)
685 {
686 struct ep_data *epdata = iocb->ki_filp->private_data;
687 char *buf;
688
689 if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
690 return -EINVAL;
691
692 buf = kmalloc(iocb->ki_left, GFP_KERNEL);
693 if (unlikely(!buf))
694 return -ENOMEM;
695
696 iocb->ki_retry = ep_aio_read_retry;
697 return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
698 }
699
700 static ssize_t
701 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
702 unsigned long nr_segs, loff_t o)
703 {
704 struct ep_data *epdata = iocb->ki_filp->private_data;
705 char *buf;
706 size_t len = 0;
707 int i = 0;
708
709 if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
710 return -EINVAL;
711
712 buf = kmalloc(iocb->ki_left, GFP_KERNEL);
713 if (unlikely(!buf))
714 return -ENOMEM;
715
716 for (i=0; i < nr_segs; i++) {
717 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
718 iov[i].iov_len) != 0)) {
719 kfree(buf);
720 return -EFAULT;
721 }
722 len += iov[i].iov_len;
723 }
724 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
725 }
726
727 /*----------------------------------------------------------------------*/
728
729 /* used after endpoint configuration */
730 static const struct file_operations ep_io_operations = {
731 .owner = THIS_MODULE,
732 .llseek = no_llseek,
733
734 .read = ep_read,
735 .write = ep_write,
736 .unlocked_ioctl = ep_ioctl,
737 .release = ep_release,
738
739 .aio_read = ep_aio_read,
740 .aio_write = ep_aio_write,
741 };
742
743 /* ENDPOINT INITIALIZATION
744 *
745 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
746 * status = write (fd, descriptors, sizeof descriptors)
747 *
748 * That write establishes the endpoint configuration, configuring
749 * the controller to process bulk, interrupt, or isochronous transfers
750 * at the right maxpacket size, and so on.
751 *
752 * The descriptors are message type 1, identified by a host order u32
753 * at the beginning of what's written. Descriptor order is: full/low
754 * speed descriptor, then optional high speed descriptor.
755 */
756 static ssize_t
757 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
758 {
759 struct ep_data *data = fd->private_data;
760 struct usb_ep *ep;
761 u32 tag;
762 int value, length = len;
763
764 value = mutex_lock_interruptible(&data->lock);
765 if (value < 0)
766 return value;
767
768 if (data->state != STATE_EP_READY) {
769 value = -EL2HLT;
770 goto fail;
771 }
772
773 value = len;
774 if (len < USB_DT_ENDPOINT_SIZE + 4)
775 goto fail0;
776
777 /* we might need to change message format someday */
778 if (copy_from_user (&tag, buf, 4)) {
779 goto fail1;
780 }
781 if (tag != 1) {
782 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
783 goto fail0;
784 }
785 buf += 4;
786 len -= 4;
787
788 /* NOTE: audio endpoint extensions not accepted here;
789 * just don't include the extra bytes.
790 */
791
792 /* full/low speed descriptor, then high speed */
793 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
794 goto fail1;
795 }
796 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
797 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
798 goto fail0;
799 if (len != USB_DT_ENDPOINT_SIZE) {
800 if (len != 2 * USB_DT_ENDPOINT_SIZE)
801 goto fail0;
802 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
803 USB_DT_ENDPOINT_SIZE)) {
804 goto fail1;
805 }
806 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
807 || data->hs_desc.bDescriptorType
808 != USB_DT_ENDPOINT) {
809 DBG(data->dev, "config %s, bad hs length or type\n",
810 data->name);
811 goto fail0;
812 }
813 }
814
815 spin_lock_irq (&data->dev->lock);
816 if (data->dev->state == STATE_DEV_UNBOUND) {
817 value = -ENOENT;
818 goto gone;
819 } else if ((ep = data->ep) == NULL) {
820 value = -ENODEV;
821 goto gone;
822 }
823 switch (data->dev->gadget->speed) {
824 case USB_SPEED_LOW:
825 case USB_SPEED_FULL:
826 ep->desc = &data->desc;
827 value = usb_ep_enable(ep);
828 if (value == 0)
829 data->state = STATE_EP_ENABLED;
830 break;
831 #ifdef CONFIG_USB_GADGET_DUALSPEED
832 case USB_SPEED_HIGH:
833 /* fails if caller didn't provide that descriptor... */
834 ep->desc = &data->hs_desc;
835 value = usb_ep_enable(ep);
836 if (value == 0)
837 data->state = STATE_EP_ENABLED;
838 break;
839 #endif
840 default:
841 DBG(data->dev, "unconnected, %s init abandoned\n",
842 data->name);
843 value = -EINVAL;
844 }
845 if (value == 0) {
846 fd->f_op = &ep_io_operations;
847 value = length;
848 }
849 gone:
850 spin_unlock_irq (&data->dev->lock);
851 if (value < 0) {
852 fail:
853 data->desc.bDescriptorType = 0;
854 data->hs_desc.bDescriptorType = 0;
855 }
856 mutex_unlock(&data->lock);
857 return value;
858 fail0:
859 value = -EINVAL;
860 goto fail;
861 fail1:
862 value = -EFAULT;
863 goto fail;
864 }
865
866 static int
867 ep_open (struct inode *inode, struct file *fd)
868 {
869 struct ep_data *data = inode->i_private;
870 int value = -EBUSY;
871
872 if (mutex_lock_interruptible(&data->lock) != 0)
873 return -EINTR;
874 spin_lock_irq (&data->dev->lock);
875 if (data->dev->state == STATE_DEV_UNBOUND)
876 value = -ENOENT;
877 else if (data->state == STATE_EP_DISABLED) {
878 value = 0;
879 data->state = STATE_EP_READY;
880 get_ep (data);
881 fd->private_data = data;
882 VDEBUG (data->dev, "%s ready\n", data->name);
883 } else
884 DBG (data->dev, "%s state %d\n",
885 data->name, data->state);
886 spin_unlock_irq (&data->dev->lock);
887 mutex_unlock(&data->lock);
888 return value;
889 }
890
891 /* used before endpoint configuration */
892 static const struct file_operations ep_config_operations = {
893 .owner = THIS_MODULE,
894 .llseek = no_llseek,
895
896 .open = ep_open,
897 .write = ep_config,
898 .release = ep_release,
899 };
900
901 /*----------------------------------------------------------------------*/
902
903 /* EP0 IMPLEMENTATION can be partly in userspace.
904 *
905 * Drivers that use this facility receive various events, including
906 * control requests the kernel doesn't handle. Drivers that don't
907 * use this facility may be too simple-minded for real applications.
908 */
909
910 static inline void ep0_readable (struct dev_data *dev)
911 {
912 wake_up (&dev->wait);
913 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
914 }
915
916 static void clean_req (struct usb_ep *ep, struct usb_request *req)
917 {
918 struct dev_data *dev = ep->driver_data;
919
920 if (req->buf != dev->rbuf) {
921 kfree(req->buf);
922 req->buf = dev->rbuf;
923 req->dma = DMA_ADDR_INVALID;
924 }
925 req->complete = epio_complete;
926 dev->setup_out_ready = 0;
927 }
928
929 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
930 {
931 struct dev_data *dev = ep->driver_data;
932 unsigned long flags;
933 int free = 1;
934
935 /* for control OUT, data must still get to userspace */
936 spin_lock_irqsave(&dev->lock, flags);
937 if (!dev->setup_in) {
938 dev->setup_out_error = (req->status != 0);
939 if (!dev->setup_out_error)
940 free = 0;
941 dev->setup_out_ready = 1;
942 ep0_readable (dev);
943 }
944
945 /* clean up as appropriate */
946 if (free && req->buf != &dev->rbuf)
947 clean_req (ep, req);
948 req->complete = epio_complete;
949 spin_unlock_irqrestore(&dev->lock, flags);
950 }
951
952 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
953 {
954 struct dev_data *dev = ep->driver_data;
955
956 if (dev->setup_out_ready) {
957 DBG (dev, "ep0 request busy!\n");
958 return -EBUSY;
959 }
960 if (len > sizeof (dev->rbuf))
961 req->buf = kmalloc(len, GFP_ATOMIC);
962 if (req->buf == NULL) {
963 req->buf = dev->rbuf;
964 return -ENOMEM;
965 }
966 req->complete = ep0_complete;
967 req->length = len;
968 req->zero = 0;
969 return 0;
970 }
971
972 static ssize_t
973 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
974 {
975 struct dev_data *dev = fd->private_data;
976 ssize_t retval;
977 enum ep0_state state;
978
979 spin_lock_irq (&dev->lock);
980
981 /* report fd mode change before acting on it */
982 if (dev->setup_abort) {
983 dev->setup_abort = 0;
984 retval = -EIDRM;
985 goto done;
986 }
987
988 /* control DATA stage */
989 if ((state = dev->state) == STATE_DEV_SETUP) {
990
991 if (dev->setup_in) { /* stall IN */
992 VDEBUG(dev, "ep0in stall\n");
993 (void) usb_ep_set_halt (dev->gadget->ep0);
994 retval = -EL2HLT;
995 dev->state = STATE_DEV_CONNECTED;
996
997 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
998 struct usb_ep *ep = dev->gadget->ep0;
999 struct usb_request *req = dev->req;
1000
1001 if ((retval = setup_req (ep, req, 0)) == 0)
1002 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1003 dev->state = STATE_DEV_CONNECTED;
1004
1005 /* assume that was SET_CONFIGURATION */
1006 if (dev->current_config) {
1007 unsigned power;
1008
1009 if (gadget_is_dualspeed(dev->gadget)
1010 && (dev->gadget->speed
1011 == USB_SPEED_HIGH))
1012 power = dev->hs_config->bMaxPower;
1013 else
1014 power = dev->config->bMaxPower;
1015 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1016 }
1017
1018 } else { /* collect OUT data */
1019 if ((fd->f_flags & O_NONBLOCK) != 0
1020 && !dev->setup_out_ready) {
1021 retval = -EAGAIN;
1022 goto done;
1023 }
1024 spin_unlock_irq (&dev->lock);
1025 retval = wait_event_interruptible (dev->wait,
1026 dev->setup_out_ready != 0);
1027
1028 /* FIXME state could change from under us */
1029 spin_lock_irq (&dev->lock);
1030 if (retval)
1031 goto done;
1032
1033 if (dev->state != STATE_DEV_SETUP) {
1034 retval = -ECANCELED;
1035 goto done;
1036 }
1037 dev->state = STATE_DEV_CONNECTED;
1038
1039 if (dev->setup_out_error)
1040 retval = -EIO;
1041 else {
1042 len = min (len, (size_t)dev->req->actual);
1043 // FIXME don't call this with the spinlock held ...
1044 if (copy_to_user (buf, dev->req->buf, len))
1045 retval = -EFAULT;
1046 clean_req (dev->gadget->ep0, dev->req);
1047 /* NOTE userspace can't yet choose to stall */
1048 }
1049 }
1050 goto done;
1051 }
1052
1053 /* else normal: return event data */
1054 if (len < sizeof dev->event [0]) {
1055 retval = -EINVAL;
1056 goto done;
1057 }
1058 len -= len % sizeof (struct usb_gadgetfs_event);
1059 dev->usermode_setup = 1;
1060
1061 scan:
1062 /* return queued events right away */
1063 if (dev->ev_next != 0) {
1064 unsigned i, n;
1065
1066 n = len / sizeof (struct usb_gadgetfs_event);
1067 if (dev->ev_next < n)
1068 n = dev->ev_next;
1069
1070 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1071 for (i = 0; i < n; i++) {
1072 if (dev->event [i].type == GADGETFS_SETUP) {
1073 dev->state = STATE_DEV_SETUP;
1074 n = i + 1;
1075 break;
1076 }
1077 }
1078 spin_unlock_irq (&dev->lock);
1079 len = n * sizeof (struct usb_gadgetfs_event);
1080 if (copy_to_user (buf, &dev->event, len))
1081 retval = -EFAULT;
1082 else
1083 retval = len;
1084 if (len > 0) {
1085 /* NOTE this doesn't guard against broken drivers;
1086 * concurrent ep0 readers may lose events.
1087 */
1088 spin_lock_irq (&dev->lock);
1089 if (dev->ev_next > n) {
1090 memmove(&dev->event[0], &dev->event[n],
1091 sizeof (struct usb_gadgetfs_event)
1092 * (dev->ev_next - n));
1093 }
1094 dev->ev_next -= n;
1095 spin_unlock_irq (&dev->lock);
1096 }
1097 return retval;
1098 }
1099 if (fd->f_flags & O_NONBLOCK) {
1100 retval = -EAGAIN;
1101 goto done;
1102 }
1103
1104 switch (state) {
1105 default:
1106 DBG (dev, "fail %s, state %d\n", __func__, state);
1107 retval = -ESRCH;
1108 break;
1109 case STATE_DEV_UNCONNECTED:
1110 case STATE_DEV_CONNECTED:
1111 spin_unlock_irq (&dev->lock);
1112 DBG (dev, "%s wait\n", __func__);
1113
1114 /* wait for events */
1115 retval = wait_event_interruptible (dev->wait,
1116 dev->ev_next != 0);
1117 if (retval < 0)
1118 return retval;
1119 spin_lock_irq (&dev->lock);
1120 goto scan;
1121 }
1122
1123 done:
1124 spin_unlock_irq (&dev->lock);
1125 return retval;
1126 }
1127
1128 static struct usb_gadgetfs_event *
1129 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1130 {
1131 struct usb_gadgetfs_event *event;
1132 unsigned i;
1133
1134 switch (type) {
1135 /* these events purge the queue */
1136 case GADGETFS_DISCONNECT:
1137 if (dev->state == STATE_DEV_SETUP)
1138 dev->setup_abort = 1;
1139 // FALL THROUGH
1140 case GADGETFS_CONNECT:
1141 dev->ev_next = 0;
1142 break;
1143 case GADGETFS_SETUP: /* previous request timed out */
1144 case GADGETFS_SUSPEND: /* same effect */
1145 /* these events can't be repeated */
1146 for (i = 0; i != dev->ev_next; i++) {
1147 if (dev->event [i].type != type)
1148 continue;
1149 DBG(dev, "discard old event[%d] %d\n", i, type);
1150 dev->ev_next--;
1151 if (i == dev->ev_next)
1152 break;
1153 /* indices start at zero, for simplicity */
1154 memmove (&dev->event [i], &dev->event [i + 1],
1155 sizeof (struct usb_gadgetfs_event)
1156 * (dev->ev_next - i));
1157 }
1158 break;
1159 default:
1160 BUG ();
1161 }
1162 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1163 event = &dev->event [dev->ev_next++];
1164 BUG_ON (dev->ev_next > N_EVENT);
1165 memset (event, 0, sizeof *event);
1166 event->type = type;
1167 return event;
1168 }
1169
1170 static ssize_t
1171 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1172 {
1173 struct dev_data *dev = fd->private_data;
1174 ssize_t retval = -ESRCH;
1175
1176 spin_lock_irq (&dev->lock);
1177
1178 /* report fd mode change before acting on it */
1179 if (dev->setup_abort) {
1180 dev->setup_abort = 0;
1181 retval = -EIDRM;
1182
1183 /* data and/or status stage for control request */
1184 } else if (dev->state == STATE_DEV_SETUP) {
1185
1186 /* IN DATA+STATUS caller makes len <= wLength */
1187 if (dev->setup_in) {
1188 retval = setup_req (dev->gadget->ep0, dev->req, len);
1189 if (retval == 0) {
1190 dev->state = STATE_DEV_CONNECTED;
1191 spin_unlock_irq (&dev->lock);
1192 if (copy_from_user (dev->req->buf, buf, len))
1193 retval = -EFAULT;
1194 else {
1195 if (len < dev->setup_wLength)
1196 dev->req->zero = 1;
1197 retval = usb_ep_queue (
1198 dev->gadget->ep0, dev->req,
1199 GFP_KERNEL);
1200 }
1201 if (retval < 0) {
1202 spin_lock_irq (&dev->lock);
1203 clean_req (dev->gadget->ep0, dev->req);
1204 spin_unlock_irq (&dev->lock);
1205 } else
1206 retval = len;
1207
1208 return retval;
1209 }
1210
1211 /* can stall some OUT transfers */
1212 } else if (dev->setup_can_stall) {
1213 VDEBUG(dev, "ep0out stall\n");
1214 (void) usb_ep_set_halt (dev->gadget->ep0);
1215 retval = -EL2HLT;
1216 dev->state = STATE_DEV_CONNECTED;
1217 } else {
1218 DBG(dev, "bogus ep0out stall!\n");
1219 }
1220 } else
1221 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1222
1223 spin_unlock_irq (&dev->lock);
1224 return retval;
1225 }
1226
1227 static int
1228 ep0_fasync (int f, struct file *fd, int on)
1229 {
1230 struct dev_data *dev = fd->private_data;
1231 // caller must F_SETOWN before signal delivery happens
1232 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1233 return fasync_helper (f, fd, on, &dev->fasync);
1234 }
1235
1236 static struct usb_gadget_driver gadgetfs_driver;
1237
1238 static int
1239 dev_release (struct inode *inode, struct file *fd)
1240 {
1241 struct dev_data *dev = fd->private_data;
1242
1243 /* closing ep0 === shutdown all */
1244
1245 usb_gadget_unregister_driver (&gadgetfs_driver);
1246
1247 /* at this point "good" hardware has disconnected the
1248 * device from USB; the host won't see it any more.
1249 * alternatively, all host requests will time out.
1250 */
1251
1252 kfree (dev->buf);
1253 dev->buf = NULL;
1254 put_dev (dev);
1255
1256 /* other endpoints were all decoupled from this device */
1257 spin_lock_irq(&dev->lock);
1258 dev->state = STATE_DEV_DISABLED;
1259 spin_unlock_irq(&dev->lock);
1260 return 0;
1261 }
1262
1263 static unsigned int
1264 ep0_poll (struct file *fd, poll_table *wait)
1265 {
1266 struct dev_data *dev = fd->private_data;
1267 int mask = 0;
1268
1269 poll_wait(fd, &dev->wait, wait);
1270
1271 spin_lock_irq (&dev->lock);
1272
1273 /* report fd mode change before acting on it */
1274 if (dev->setup_abort) {
1275 dev->setup_abort = 0;
1276 mask = POLLHUP;
1277 goto out;
1278 }
1279
1280 if (dev->state == STATE_DEV_SETUP) {
1281 if (dev->setup_in || dev->setup_can_stall)
1282 mask = POLLOUT;
1283 } else {
1284 if (dev->ev_next != 0)
1285 mask = POLLIN;
1286 }
1287 out:
1288 spin_unlock_irq(&dev->lock);
1289 return mask;
1290 }
1291
1292 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1293 {
1294 struct dev_data *dev = fd->private_data;
1295 struct usb_gadget *gadget = dev->gadget;
1296 long ret = -ENOTTY;
1297
1298 if (gadget->ops->ioctl)
1299 ret = gadget->ops->ioctl (gadget, code, value);
1300
1301 return ret;
1302 }
1303
1304 /* used after device configuration */
1305 static const struct file_operations ep0_io_operations = {
1306 .owner = THIS_MODULE,
1307 .llseek = no_llseek,
1308
1309 .read = ep0_read,
1310 .write = ep0_write,
1311 .fasync = ep0_fasync,
1312 .poll = ep0_poll,
1313 .unlocked_ioctl = dev_ioctl,
1314 .release = dev_release,
1315 };
1316
1317 /*----------------------------------------------------------------------*/
1318
1319 /* The in-kernel gadget driver handles most ep0 issues, in particular
1320 * enumerating the single configuration (as provided from user space).
1321 *
1322 * Unrecognized ep0 requests may be handled in user space.
1323 */
1324
1325 #ifdef CONFIG_USB_GADGET_DUALSPEED
1326 static void make_qualifier (struct dev_data *dev)
1327 {
1328 struct usb_qualifier_descriptor qual;
1329 struct usb_device_descriptor *desc;
1330
1331 qual.bLength = sizeof qual;
1332 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1333 qual.bcdUSB = cpu_to_le16 (0x0200);
1334
1335 desc = dev->dev;
1336 qual.bDeviceClass = desc->bDeviceClass;
1337 qual.bDeviceSubClass = desc->bDeviceSubClass;
1338 qual.bDeviceProtocol = desc->bDeviceProtocol;
1339
1340 /* assumes ep0 uses the same value for both speeds ... */
1341 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1342
1343 qual.bNumConfigurations = 1;
1344 qual.bRESERVED = 0;
1345
1346 memcpy (dev->rbuf, &qual, sizeof qual);
1347 }
1348 #endif
1349
1350 static int
1351 config_buf (struct dev_data *dev, u8 type, unsigned index)
1352 {
1353 int len;
1354 int hs = 0;
1355
1356 /* only one configuration */
1357 if (index > 0)
1358 return -EINVAL;
1359
1360 if (gadget_is_dualspeed(dev->gadget)) {
1361 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1362 if (type == USB_DT_OTHER_SPEED_CONFIG)
1363 hs = !hs;
1364 }
1365 if (hs) {
1366 dev->req->buf = dev->hs_config;
1367 len = le16_to_cpu(dev->hs_config->wTotalLength);
1368 } else {
1369 dev->req->buf = dev->config;
1370 len = le16_to_cpu(dev->config->wTotalLength);
1371 }
1372 ((u8 *)dev->req->buf) [1] = type;
1373 return len;
1374 }
1375
1376 static int
1377 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1378 {
1379 struct dev_data *dev = get_gadget_data (gadget);
1380 struct usb_request *req = dev->req;
1381 int value = -EOPNOTSUPP;
1382 struct usb_gadgetfs_event *event;
1383 u16 w_value = le16_to_cpu(ctrl->wValue);
1384 u16 w_length = le16_to_cpu(ctrl->wLength);
1385
1386 spin_lock (&dev->lock);
1387 dev->setup_abort = 0;
1388 if (dev->state == STATE_DEV_UNCONNECTED) {
1389 if (gadget_is_dualspeed(gadget)
1390 && gadget->speed == USB_SPEED_HIGH
1391 && dev->hs_config == NULL) {
1392 spin_unlock(&dev->lock);
1393 ERROR (dev, "no high speed config??\n");
1394 return -EINVAL;
1395 }
1396
1397 dev->state = STATE_DEV_CONNECTED;
1398
1399 INFO (dev, "connected\n");
1400 event = next_event (dev, GADGETFS_CONNECT);
1401 event->u.speed = gadget->speed;
1402 ep0_readable (dev);
1403
1404 /* host may have given up waiting for response. we can miss control
1405 * requests handled lower down (device/endpoint status and features);
1406 * then ep0_{read,write} will report the wrong status. controller
1407 * driver will have aborted pending i/o.
1408 */
1409 } else if (dev->state == STATE_DEV_SETUP)
1410 dev->setup_abort = 1;
1411
1412 req->buf = dev->rbuf;
1413 req->dma = DMA_ADDR_INVALID;
1414 req->context = NULL;
1415 value = -EOPNOTSUPP;
1416 switch (ctrl->bRequest) {
1417
1418 case USB_REQ_GET_DESCRIPTOR:
1419 if (ctrl->bRequestType != USB_DIR_IN)
1420 goto unrecognized;
1421 switch (w_value >> 8) {
1422
1423 case USB_DT_DEVICE:
1424 value = min (w_length, (u16) sizeof *dev->dev);
1425 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1426 req->buf = dev->dev;
1427 break;
1428 #ifdef CONFIG_USB_GADGET_DUALSPEED
1429 case USB_DT_DEVICE_QUALIFIER:
1430 if (!dev->hs_config)
1431 break;
1432 value = min (w_length, (u16)
1433 sizeof (struct usb_qualifier_descriptor));
1434 make_qualifier (dev);
1435 break;
1436 case USB_DT_OTHER_SPEED_CONFIG:
1437 // FALLTHROUGH
1438 #endif
1439 case USB_DT_CONFIG:
1440 value = config_buf (dev,
1441 w_value >> 8,
1442 w_value & 0xff);
1443 if (value >= 0)
1444 value = min (w_length, (u16) value);
1445 break;
1446 case USB_DT_STRING:
1447 goto unrecognized;
1448
1449 default: // all others are errors
1450 break;
1451 }
1452 break;
1453
1454 /* currently one config, two speeds */
1455 case USB_REQ_SET_CONFIGURATION:
1456 if (ctrl->bRequestType != 0)
1457 goto unrecognized;
1458 if (0 == (u8) w_value) {
1459 value = 0;
1460 dev->current_config = 0;
1461 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1462 // user mode expected to disable endpoints
1463 } else {
1464 u8 config, power;
1465
1466 if (gadget_is_dualspeed(gadget)
1467 && gadget->speed == USB_SPEED_HIGH) {
1468 config = dev->hs_config->bConfigurationValue;
1469 power = dev->hs_config->bMaxPower;
1470 } else {
1471 config = dev->config->bConfigurationValue;
1472 power = dev->config->bMaxPower;
1473 }
1474
1475 if (config == (u8) w_value) {
1476 value = 0;
1477 dev->current_config = config;
1478 usb_gadget_vbus_draw(gadget, 2 * power);
1479 }
1480 }
1481
1482 /* report SET_CONFIGURATION like any other control request,
1483 * except that usermode may not stall this. the next
1484 * request mustn't be allowed start until this finishes:
1485 * endpoints and threads set up, etc.
1486 *
1487 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1488 * has bad/racey automagic that prevents synchronizing here.
1489 * even kernel mode drivers often miss them.
1490 */
1491 if (value == 0) {
1492 INFO (dev, "configuration #%d\n", dev->current_config);
1493 if (dev->usermode_setup) {
1494 dev->setup_can_stall = 0;
1495 goto delegate;
1496 }
1497 }
1498 break;
1499
1500 #ifndef CONFIG_USB_GADGET_PXA25X
1501 /* PXA automagically handles this request too */
1502 case USB_REQ_GET_CONFIGURATION:
1503 if (ctrl->bRequestType != 0x80)
1504 goto unrecognized;
1505 *(u8 *)req->buf = dev->current_config;
1506 value = min (w_length, (u16) 1);
1507 break;
1508 #endif
1509
1510 default:
1511 unrecognized:
1512 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1513 dev->usermode_setup ? "delegate" : "fail",
1514 ctrl->bRequestType, ctrl->bRequest,
1515 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1516
1517 /* if there's an ep0 reader, don't stall */
1518 if (dev->usermode_setup) {
1519 dev->setup_can_stall = 1;
1520 delegate:
1521 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1522 ? 1 : 0;
1523 dev->setup_wLength = w_length;
1524 dev->setup_out_ready = 0;
1525 dev->setup_out_error = 0;
1526 value = 0;
1527
1528 /* read DATA stage for OUT right away */
1529 if (unlikely (!dev->setup_in && w_length)) {
1530 value = setup_req (gadget->ep0, dev->req,
1531 w_length);
1532 if (value < 0)
1533 break;
1534 value = usb_ep_queue (gadget->ep0, dev->req,
1535 GFP_ATOMIC);
1536 if (value < 0) {
1537 clean_req (gadget->ep0, dev->req);
1538 break;
1539 }
1540
1541 /* we can't currently stall these */
1542 dev->setup_can_stall = 0;
1543 }
1544
1545 /* state changes when reader collects event */
1546 event = next_event (dev, GADGETFS_SETUP);
1547 event->u.setup = *ctrl;
1548 ep0_readable (dev);
1549 spin_unlock (&dev->lock);
1550 return 0;
1551 }
1552 }
1553
1554 /* proceed with data transfer and status phases? */
1555 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1556 req->length = value;
1557 req->zero = value < w_length;
1558 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1559 if (value < 0) {
1560 DBG (dev, "ep_queue --> %d\n", value);
1561 req->status = 0;
1562 }
1563 }
1564
1565 /* device stalls when value < 0 */
1566 spin_unlock (&dev->lock);
1567 return value;
1568 }
1569
1570 static void destroy_ep_files (struct dev_data *dev)
1571 {
1572 struct list_head *entry, *tmp;
1573
1574 DBG (dev, "%s %d\n", __func__, dev->state);
1575
1576 /* dev->state must prevent interference */
1577 restart:
1578 spin_lock_irq (&dev->lock);
1579 list_for_each_safe (entry, tmp, &dev->epfiles) {
1580 struct ep_data *ep;
1581 struct inode *parent;
1582 struct dentry *dentry;
1583
1584 /* break link to FS */
1585 ep = list_entry (entry, struct ep_data, epfiles);
1586 list_del_init (&ep->epfiles);
1587 dentry = ep->dentry;
1588 ep->dentry = NULL;
1589 parent = dentry->d_parent->d_inode;
1590
1591 /* break link to controller */
1592 if (ep->state == STATE_EP_ENABLED)
1593 (void) usb_ep_disable (ep->ep);
1594 ep->state = STATE_EP_UNBOUND;
1595 usb_ep_free_request (ep->ep, ep->req);
1596 ep->ep = NULL;
1597 wake_up (&ep->wait);
1598 put_ep (ep);
1599
1600 spin_unlock_irq (&dev->lock);
1601
1602 /* break link to dcache */
1603 mutex_lock (&parent->i_mutex);
1604 d_delete (dentry);
1605 dput (dentry);
1606 mutex_unlock (&parent->i_mutex);
1607
1608 /* fds may still be open */
1609 goto restart;
1610 }
1611 spin_unlock_irq (&dev->lock);
1612 }
1613
1614
1615 static struct inode *
1616 gadgetfs_create_file (struct super_block *sb, char const *name,
1617 void *data, const struct file_operations *fops,
1618 struct dentry **dentry_p);
1619
1620 static 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
1655 enomem2:
1656 usb_ep_free_request (ep, data->req);
1657 enomem1:
1658 put_dev (dev);
1659 kfree (data);
1660 enomem0:
1661 DBG (dev, "%s enomem\n", __func__);
1662 destroy_ep_files (dev);
1663 return -ENOMEM;
1664 }
1665
1666 static void
1667 gadgetfs_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
1688 static struct dev_data *the_device;
1689
1690 static int
1691 gadgetfs_bind (struct usb_gadget *gadget)
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
1724 enomem:
1725 gadgetfs_unbind (gadget);
1726 return -ENOMEM;
1727 }
1728
1729 static void
1730 gadgetfs_disconnect (struct usb_gadget *gadget)
1731 {
1732 struct dev_data *dev = get_gadget_data (gadget);
1733
1734 spin_lock (&dev->lock);
1735 if (dev->state == STATE_DEV_UNCONNECTED)
1736 goto exit;
1737 dev->state = STATE_DEV_UNCONNECTED;
1738
1739 INFO (dev, "disconnected\n");
1740 next_event (dev, GADGETFS_DISCONNECT);
1741 ep0_readable (dev);
1742 exit:
1743 spin_unlock (&dev->lock);
1744 }
1745
1746 static void
1747 gadgetfs_suspend (struct usb_gadget *gadget)
1748 {
1749 struct dev_data *dev = get_gadget_data (gadget);
1750
1751 INFO (dev, "suspended from state %d\n", dev->state);
1752 spin_lock (&dev->lock);
1753 switch (dev->state) {
1754 case STATE_DEV_SETUP: // VERY odd... host died??
1755 case STATE_DEV_CONNECTED:
1756 case STATE_DEV_UNCONNECTED:
1757 next_event (dev, GADGETFS_SUSPEND);
1758 ep0_readable (dev);
1759 /* FALLTHROUGH */
1760 default:
1761 break;
1762 }
1763 spin_unlock (&dev->lock);
1764 }
1765
1766 static struct usb_gadget_driver gadgetfs_driver = {
1767 #ifdef CONFIG_USB_GADGET_DUALSPEED
1768 .speed = USB_SPEED_HIGH,
1769 #else
1770 .speed = USB_SPEED_FULL,
1771 #endif
1772 .function = (char *) driver_desc,
1773 .unbind = gadgetfs_unbind,
1774 .setup = gadgetfs_setup,
1775 .disconnect = gadgetfs_disconnect,
1776 .suspend = gadgetfs_suspend,
1777
1778 .driver = {
1779 .name = (char *) shortname,
1780 },
1781 };
1782
1783 /*----------------------------------------------------------------------*/
1784
1785 static void gadgetfs_nop(struct usb_gadget *arg) { }
1786
1787 static int gadgetfs_probe (struct usb_gadget *gadget)
1788 {
1789 CHIP = gadget->name;
1790 return -EISNAM;
1791 }
1792
1793 static struct usb_gadget_driver probe_driver = {
1794 .speed = USB_SPEED_HIGH,
1795 .unbind = gadgetfs_nop,
1796 .setup = (void *)gadgetfs_nop,
1797 .disconnect = gadgetfs_nop,
1798 .driver = {
1799 .name = "nop",
1800 },
1801 };
1802
1803
1804 /* DEVICE INITIALIZATION
1805 *
1806 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1807 * status = write (fd, descriptors, sizeof descriptors)
1808 *
1809 * That write establishes the device configuration, so the kernel can
1810 * bind to the controller ... guaranteeing it can handle enumeration
1811 * at all necessary speeds. Descriptor order is:
1812 *
1813 * . message tag (u32, host order) ... for now, must be zero; it
1814 * would change to support features like multi-config devices
1815 * . full/low speed config ... all wTotalLength bytes (with interface,
1816 * class, altsetting, endpoint, and other descriptors)
1817 * . high speed config ... all descriptors, for high speed operation;
1818 * this one's optional except for high-speed hardware
1819 * . device descriptor
1820 *
1821 * Endpoints are not yet enabled. Drivers must wait until device
1822 * configuration and interface altsetting changes create
1823 * the need to configure (or unconfigure) them.
1824 *
1825 * After initialization, the device stays active for as long as that
1826 * $CHIP file is open. Events must then be read from that descriptor,
1827 * such as configuration notifications.
1828 */
1829
1830 static int is_valid_config (struct usb_config_descriptor *config)
1831 {
1832 return config->bDescriptorType == USB_DT_CONFIG
1833 && config->bLength == USB_DT_CONFIG_SIZE
1834 && config->bConfigurationValue != 0
1835 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1836 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1837 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1838 /* FIXME check lengths: walk to end */
1839 }
1840
1841 static ssize_t
1842 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1843 {
1844 struct dev_data *dev = fd->private_data;
1845 ssize_t value = len, length = len;
1846 unsigned total;
1847 u32 tag;
1848 char *kbuf;
1849
1850 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1851 return -EINVAL;
1852
1853 /* we might need to change message format someday */
1854 if (copy_from_user (&tag, buf, 4))
1855 return -EFAULT;
1856 if (tag != 0)
1857 return -EINVAL;
1858 buf += 4;
1859 length -= 4;
1860
1861 kbuf = memdup_user(buf, length);
1862 if (IS_ERR(kbuf))
1863 return PTR_ERR(kbuf);
1864
1865 spin_lock_irq (&dev->lock);
1866 value = -EINVAL;
1867 if (dev->buf)
1868 goto fail;
1869 dev->buf = kbuf;
1870
1871 /* full or low speed config */
1872 dev->config = (void *) kbuf;
1873 total = le16_to_cpu(dev->config->wTotalLength);
1874 if (!is_valid_config (dev->config) || total >= length)
1875 goto fail;
1876 kbuf += total;
1877 length -= total;
1878
1879 /* optional high speed config */
1880 if (kbuf [1] == USB_DT_CONFIG) {
1881 dev->hs_config = (void *) kbuf;
1882 total = le16_to_cpu(dev->hs_config->wTotalLength);
1883 if (!is_valid_config (dev->hs_config) || total >= length)
1884 goto fail;
1885 kbuf += total;
1886 length -= total;
1887 }
1888
1889 /* could support multiple configs, using another encoding! */
1890
1891 /* device descriptor (tweaked for paranoia) */
1892 if (length != USB_DT_DEVICE_SIZE)
1893 goto fail;
1894 dev->dev = (void *)kbuf;
1895 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1896 || dev->dev->bDescriptorType != USB_DT_DEVICE
1897 || dev->dev->bNumConfigurations != 1)
1898 goto fail;
1899 dev->dev->bNumConfigurations = 1;
1900 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1901
1902 /* triggers gadgetfs_bind(); then we can enumerate. */
1903 spin_unlock_irq (&dev->lock);
1904 value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1905 if (value != 0) {
1906 kfree (dev->buf);
1907 dev->buf = NULL;
1908 } else {
1909 /* at this point "good" hardware has for the first time
1910 * let the USB the host see us. alternatively, if users
1911 * unplug/replug that will clear all the error state.
1912 *
1913 * note: everything running before here was guaranteed
1914 * to choke driver model style diagnostics. from here
1915 * on, they can work ... except in cleanup paths that
1916 * kick in after the ep0 descriptor is closed.
1917 */
1918 fd->f_op = &ep0_io_operations;
1919 value = len;
1920 }
1921 return value;
1922
1923 fail:
1924 spin_unlock_irq (&dev->lock);
1925 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1926 kfree (dev->buf);
1927 dev->buf = NULL;
1928 return value;
1929 }
1930
1931 static int
1932 dev_open (struct inode *inode, struct file *fd)
1933 {
1934 struct dev_data *dev = inode->i_private;
1935 int value = -EBUSY;
1936
1937 spin_lock_irq(&dev->lock);
1938 if (dev->state == STATE_DEV_DISABLED) {
1939 dev->ev_next = 0;
1940 dev->state = STATE_DEV_OPENED;
1941 fd->private_data = dev;
1942 get_dev (dev);
1943 value = 0;
1944 }
1945 spin_unlock_irq(&dev->lock);
1946 return value;
1947 }
1948
1949 static const struct file_operations dev_init_operations = {
1950 .owner = THIS_MODULE,
1951 .llseek = no_llseek,
1952
1953 .open = dev_open,
1954 .write = dev_config,
1955 .fasync = ep0_fasync,
1956 .unlocked_ioctl = dev_ioctl,
1957 .release = dev_release,
1958 };
1959
1960 /*----------------------------------------------------------------------*/
1961
1962 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1963 *
1964 * Mounting the filesystem creates a controller file, used first for
1965 * device configuration then later for event monitoring.
1966 */
1967
1968
1969 /* FIXME PAM etc could set this security policy without mount options
1970 * if epfiles inherited ownership and permissons from ep0 ...
1971 */
1972
1973 static unsigned default_uid;
1974 static unsigned default_gid;
1975 static unsigned default_perm = S_IRUSR | S_IWUSR;
1976
1977 module_param (default_uid, uint, 0644);
1978 module_param (default_gid, uint, 0644);
1979 module_param (default_perm, uint, 0644);
1980
1981
1982 static struct inode *
1983 gadgetfs_make_inode (struct super_block *sb,
1984 void *data, const struct file_operations *fops,
1985 int mode)
1986 {
1987 struct inode *inode = new_inode (sb);
1988
1989 if (inode) {
1990 inode->i_ino = get_next_ino();
1991 inode->i_mode = mode;
1992 inode->i_uid = default_uid;
1993 inode->i_gid = default_gid;
1994 inode->i_atime = inode->i_mtime = inode->i_ctime
1995 = CURRENT_TIME;
1996 inode->i_private = data;
1997 inode->i_fop = fops;
1998 }
1999 return inode;
2000 }
2001
2002 /* creates in fs root directory, so non-renamable and non-linkable.
2003 * so inode and dentry are paired, until device reconfig.
2004 */
2005 static struct inode *
2006 gadgetfs_create_file (struct super_block *sb, char const *name,
2007 void *data, const struct file_operations *fops,
2008 struct dentry **dentry_p)
2009 {
2010 struct dentry *dentry;
2011 struct inode *inode;
2012
2013 dentry = d_alloc_name(sb->s_root, name);
2014 if (!dentry)
2015 return NULL;
2016
2017 inode = gadgetfs_make_inode (sb, data, fops,
2018 S_IFREG | (default_perm & S_IRWXUGO));
2019 if (!inode) {
2020 dput(dentry);
2021 return NULL;
2022 }
2023 d_add (dentry, inode);
2024 *dentry_p = dentry;
2025 return inode;
2026 }
2027
2028 static const struct super_operations gadget_fs_operations = {
2029 .statfs = simple_statfs,
2030 .drop_inode = generic_delete_inode,
2031 };
2032
2033 static int
2034 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2035 {
2036 struct inode *inode;
2037 struct dentry *d;
2038 struct dev_data *dev;
2039
2040 if (the_device)
2041 return -ESRCH;
2042
2043 /* fake probe to determine $CHIP */
2044 (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2045 if (!CHIP)
2046 return -ENODEV;
2047
2048 /* superblock */
2049 sb->s_blocksize = PAGE_CACHE_SIZE;
2050 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2051 sb->s_magic = GADGETFS_MAGIC;
2052 sb->s_op = &gadget_fs_operations;
2053 sb->s_time_gran = 1;
2054
2055 /* root inode */
2056 inode = gadgetfs_make_inode (sb,
2057 NULL, &simple_dir_operations,
2058 S_IFDIR | S_IRUGO | S_IXUGO);
2059 if (!inode)
2060 goto enomem0;
2061 inode->i_op = &simple_dir_inode_operations;
2062 if (!(d = d_alloc_root (inode)))
2063 goto enomem1;
2064 sb->s_root = d;
2065
2066 /* the ep0 file is named after the controller we expect;
2067 * user mode code can use it for sanity checks, like we do.
2068 */
2069 dev = dev_new ();
2070 if (!dev)
2071 goto enomem2;
2072
2073 dev->sb = sb;
2074 if (!gadgetfs_create_file (sb, CHIP,
2075 dev, &dev_init_operations,
2076 &dev->dentry))
2077 goto enomem3;
2078
2079 /* other endpoint files are available after hardware setup,
2080 * from binding to a controller.
2081 */
2082 the_device = dev;
2083 return 0;
2084
2085 enomem3:
2086 put_dev (dev);
2087 enomem2:
2088 dput (d);
2089 enomem1:
2090 iput (inode);
2091 enomem0:
2092 return -ENOMEM;
2093 }
2094
2095 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2096 static struct dentry *
2097 gadgetfs_mount (struct file_system_type *t, int flags,
2098 const char *path, void *opts)
2099 {
2100 return mount_single (t, flags, opts, gadgetfs_fill_super);
2101 }
2102
2103 static void
2104 gadgetfs_kill_sb (struct super_block *sb)
2105 {
2106 kill_litter_super (sb);
2107 if (the_device) {
2108 put_dev (the_device);
2109 the_device = NULL;
2110 }
2111 }
2112
2113 /*----------------------------------------------------------------------*/
2114
2115 static struct file_system_type gadgetfs_type = {
2116 .owner = THIS_MODULE,
2117 .name = shortname,
2118 .mount = gadgetfs_mount,
2119 .kill_sb = gadgetfs_kill_sb,
2120 };
2121
2122 /*----------------------------------------------------------------------*/
2123
2124 static int __init init (void)
2125 {
2126 int status;
2127
2128 status = register_filesystem (&gadgetfs_type);
2129 if (status == 0)
2130 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2131 shortname, driver_desc);
2132 return status;
2133 }
2134 module_init (init);
2135
2136 static void __exit cleanup (void)
2137 {
2138 pr_debug ("unregister %s\n", shortname);
2139 unregister_filesystem (&gadgetfs_type);
2140 }
2141 module_exit (cleanup);
2142
Linux with added FPC-III support