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USB: gadgetfs: protect ep_release with lock
[deliverable/linux.git] / drivers / usb / gadget / inode.c
1 /*
2 * inode.c -- user mode filesystem api for usb gadget controllers
3 *
4 * Copyright (C) 2003-2004 David Brownell
5 * Copyright (C) 2003 Agilent Technologies
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22
23 // #define DEBUG /* data to help fault diagnosis */
24 // #define VERBOSE /* extra debug messages (success too) */
25
26 #include <linux/init.h>
27 #include <linux/module.h>
28 #include <linux/fs.h>
29 #include <linux/pagemap.h>
30 #include <linux/uts.h>
31 #include <linux/wait.h>
32 #include <linux/compiler.h>
33 #include <asm/uaccess.h>
34 #include <linux/slab.h>
35
36 #include <linux/device.h>
37 #include <linux/moduleparam.h>
38
39 #include <linux/usb_gadgetfs.h>
40 #include <linux/usb_gadget.h>
41
42
43 /*
44 * The gadgetfs API maps each endpoint to a file descriptor so that you
45 * can use standard synchronous read/write calls for I/O. There's some
46 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
47 * drivers show how this works in practice. You can also use AIO to
48 * eliminate I/O gaps between requests, to help when streaming data.
49 *
50 * Key parts that must be USB-specific are protocols defining how the
51 * read/write operations relate to the hardware state machines. There
52 * are two types of files. One type is for the device, implementing ep0.
53 * The other type is for each IN or OUT endpoint. In both cases, the
54 * user mode driver must configure the hardware before using it.
55 *
56 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
57 * (by writing configuration and device descriptors). Afterwards it
58 * may serve as a source of device events, used to handle all control
59 * requests other than basic enumeration.
60 *
61 * - Then either immediately, or after a SET_CONFIGURATION control request,
62 * ep_config() is called when each /dev/gadget/ep* file is configured
63 * (by writing endpoint descriptors). Afterwards these files are used
64 * to write() IN data or to read() OUT data. To halt the endpoint, a
65 * "wrong direction" request is issued (like reading an IN endpoint).
66 *
67 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
68 * not possible on all hardware. For example, precise fault handling with
69 * respect to data left in endpoint fifos after aborted operations; or
70 * selective clearing of endpoint halts, to implement SET_INTERFACE.
71 */
72
73 #define DRIVER_DESC "USB Gadget filesystem"
74 #define DRIVER_VERSION "24 Aug 2004"
75
76 static const char driver_desc [] = DRIVER_DESC;
77 static const char shortname [] = "gadgetfs";
78
79 MODULE_DESCRIPTION (DRIVER_DESC);
80 MODULE_AUTHOR ("David Brownell");
81 MODULE_LICENSE ("GPL");
82
83
84 /*----------------------------------------------------------------------*/
85
86 #define GADGETFS_MAGIC 0xaee71ee7
87 #define DMA_ADDR_INVALID (~(dma_addr_t)0)
88
89 /* /dev/gadget/$CHIP represents ep0 and the whole device */
90 enum ep0_state {
91 /* DISBLED is the initial state.
92 */
93 STATE_DEV_DISABLED = 0,
94
95 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
96 * ep0/device i/o modes and binding to the controller. Driver
97 * must always write descriptors to initialize the device, then
98 * the device becomes UNCONNECTED until enumeration.
99 */
100 STATE_OPENED,
101
102 /* From then on, ep0 fd is in either of two basic modes:
103 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
104 * - SETUP: read/write will transfer control data and succeed;
105 * or if "wrong direction", performs protocol stall
106 */
107 STATE_UNCONNECTED,
108 STATE_CONNECTED,
109 STATE_SETUP,
110
111 /* UNBOUND means the driver closed ep0, so the device won't be
112 * accessible again (DEV_DISABLED) until all fds are closed.
113 */
114 STATE_DEV_UNBOUND,
115 };
116
117 /* enough for the whole queue: most events invalidate others */
118 #define N_EVENT 5
119
120 struct dev_data {
121 spinlock_t lock;
122 atomic_t count;
123 enum ep0_state state;
124 struct usb_gadgetfs_event event [N_EVENT];
125 unsigned ev_next;
126 struct fasync_struct *fasync;
127 u8 current_config;
128
129 /* drivers reading ep0 MUST handle control requests (SETUP)
130 * reported that way; else the host will time out.
131 */
132 unsigned usermode_setup : 1,
133 setup_in : 1,
134 setup_can_stall : 1,
135 setup_out_ready : 1,
136 setup_out_error : 1,
137 setup_abort : 1;
138 unsigned setup_wLength;
139
140 /* the rest is basically write-once */
141 struct usb_config_descriptor *config, *hs_config;
142 struct usb_device_descriptor *dev;
143 struct usb_request *req;
144 struct usb_gadget *gadget;
145 struct list_head epfiles;
146 void *buf;
147 wait_queue_head_t wait;
148 struct super_block *sb;
149 struct dentry *dentry;
150
151 /* except this scratch i/o buffer for ep0 */
152 u8 rbuf [256];
153 };
154
155 static inline void get_dev (struct dev_data *data)
156 {
157 atomic_inc (&data->count);
158 }
159
160 static void put_dev (struct dev_data *data)
161 {
162 if (likely (!atomic_dec_and_test (&data->count)))
163 return;
164 /* needs no more cleanup */
165 BUG_ON (waitqueue_active (&data->wait));
166 kfree (data);
167 }
168
169 static struct dev_data *dev_new (void)
170 {
171 struct dev_data *dev;
172
173 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
174 if (!dev)
175 return NULL;
176 dev->state = STATE_DEV_DISABLED;
177 atomic_set (&dev->count, 1);
178 spin_lock_init (&dev->lock);
179 INIT_LIST_HEAD (&dev->epfiles);
180 init_waitqueue_head (&dev->wait);
181 return dev;
182 }
183
184 /*----------------------------------------------------------------------*/
185
186 /* other /dev/gadget/$ENDPOINT files represent endpoints */
187 enum ep_state {
188 STATE_EP_DISABLED = 0,
189 STATE_EP_READY,
190 STATE_EP_DEFER_ENABLE,
191 STATE_EP_ENABLED,
192 STATE_EP_UNBOUND,
193 };
194
195 struct ep_data {
196 struct semaphore lock;
197 enum ep_state state;
198 atomic_t count;
199 struct dev_data *dev;
200 /* must hold dev->lock before accessing ep or req */
201 struct usb_ep *ep;
202 struct usb_request *req;
203 ssize_t status;
204 char name [16];
205 struct usb_endpoint_descriptor desc, hs_desc;
206 struct list_head epfiles;
207 wait_queue_head_t wait;
208 struct dentry *dentry;
209 struct inode *inode;
210 };
211
212 static inline void get_ep (struct ep_data *data)
213 {
214 atomic_inc (&data->count);
215 }
216
217 static void put_ep (struct ep_data *data)
218 {
219 if (likely (!atomic_dec_and_test (&data->count)))
220 return;
221 put_dev (data->dev);
222 /* needs no more cleanup */
223 BUG_ON (!list_empty (&data->epfiles));
224 BUG_ON (waitqueue_active (&data->wait));
225 BUG_ON (down_trylock (&data->lock) != 0);
226 kfree (data);
227 }
228
229 /*----------------------------------------------------------------------*/
230
231 /* most "how to use the hardware" policy choices are in userspace:
232 * mapping endpoint roles (which the driver needs) to the capabilities
233 * which the usb controller has. most of those capabilities are exposed
234 * implicitly, starting with the driver name and then endpoint names.
235 */
236
237 static const char *CHIP;
238
239 /*----------------------------------------------------------------------*/
240
241 /* NOTE: don't use dev_printk calls before binding to the gadget
242 * at the end of ep0 configuration, or after unbind.
243 */
244
245 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
246 #define xprintk(d,level,fmt,args...) \
247 printk(level "%s: " fmt , shortname , ## args)
248
249 #ifdef DEBUG
250 #define DBG(dev,fmt,args...) \
251 xprintk(dev , KERN_DEBUG , fmt , ## args)
252 #else
253 #define DBG(dev,fmt,args...) \
254 do { } while (0)
255 #endif /* DEBUG */
256
257 #ifdef VERBOSE
258 #define VDEBUG DBG
259 #else
260 #define VDEBUG(dev,fmt,args...) \
261 do { } while (0)
262 #endif /* DEBUG */
263
264 #define ERROR(dev,fmt,args...) \
265 xprintk(dev , KERN_ERR , fmt , ## args)
266 #define WARN(dev,fmt,args...) \
267 xprintk(dev , KERN_WARNING , fmt , ## args)
268 #define INFO(dev,fmt,args...) \
269 xprintk(dev , KERN_INFO , fmt , ## args)
270
271
272 /*----------------------------------------------------------------------*/
273
274 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
275 *
276 * After opening, configure non-control endpoints. Then use normal
277 * stream read() and write() requests; and maybe ioctl() to get more
278 * precise FIFO status when recovering from cancellation.
279 */
280
281 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
282 {
283 struct ep_data *epdata = ep->driver_data;
284
285 if (!req->context)
286 return;
287 if (req->status)
288 epdata->status = req->status;
289 else
290 epdata->status = req->actual;
291 complete ((struct completion *)req->context);
292 }
293
294 /* tasklock endpoint, returning when it's connected.
295 * still need dev->lock to use epdata->ep.
296 */
297 static int
298 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
299 {
300 int val;
301
302 if (f_flags & O_NONBLOCK) {
303 if (down_trylock (&epdata->lock) != 0)
304 goto nonblock;
305 if (epdata->state != STATE_EP_ENABLED) {
306 up (&epdata->lock);
307 nonblock:
308 val = -EAGAIN;
309 } else
310 val = 0;
311 return val;
312 }
313
314 if ((val = down_interruptible (&epdata->lock)) < 0)
315 return val;
316 newstate:
317 switch (epdata->state) {
318 case STATE_EP_ENABLED:
319 break;
320 case STATE_EP_DEFER_ENABLE:
321 DBG (epdata->dev, "%s wait for host\n", epdata->name);
322 if ((val = wait_event_interruptible (epdata->wait,
323 epdata->state != STATE_EP_DEFER_ENABLE
324 || epdata->dev->state == STATE_DEV_UNBOUND
325 )) < 0)
326 goto fail;
327 goto newstate;
328 // case STATE_EP_DISABLED: /* "can't happen" */
329 // case STATE_EP_READY: /* "can't happen" */
330 default: /* error! */
331 pr_debug ("%s: ep %p not available, state %d\n",
332 shortname, epdata, epdata->state);
333 // FALLTHROUGH
334 case STATE_EP_UNBOUND: /* clean disconnect */
335 val = -ENODEV;
336 fail:
337 up (&epdata->lock);
338 }
339 return val;
340 }
341
342 static ssize_t
343 ep_io (struct ep_data *epdata, void *buf, unsigned len)
344 {
345 DECLARE_COMPLETION (done);
346 int value;
347
348 spin_lock_irq (&epdata->dev->lock);
349 if (likely (epdata->ep != NULL)) {
350 struct usb_request *req = epdata->req;
351
352 req->context = &done;
353 req->complete = epio_complete;
354 req->buf = buf;
355 req->length = len;
356 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
357 } else
358 value = -ENODEV;
359 spin_unlock_irq (&epdata->dev->lock);
360
361 if (likely (value == 0)) {
362 value = wait_event_interruptible (done.wait, done.done);
363 if (value != 0) {
364 spin_lock_irq (&epdata->dev->lock);
365 if (likely (epdata->ep != NULL)) {
366 DBG (epdata->dev, "%s i/o interrupted\n",
367 epdata->name);
368 usb_ep_dequeue (epdata->ep, epdata->req);
369 spin_unlock_irq (&epdata->dev->lock);
370
371 wait_event (done.wait, done.done);
372 if (epdata->status == -ECONNRESET)
373 epdata->status = -EINTR;
374 } else {
375 spin_unlock_irq (&epdata->dev->lock);
376
377 DBG (epdata->dev, "endpoint gone\n");
378 epdata->status = -ENODEV;
379 }
380 }
381 return epdata->status;
382 }
383 return value;
384 }
385
386
387 /* handle a synchronous OUT bulk/intr/iso transfer */
388 static ssize_t
389 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
390 {
391 struct ep_data *data = fd->private_data;
392 void *kbuf;
393 ssize_t value;
394
395 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
396 return value;
397
398 /* halt any endpoint by doing a "wrong direction" i/o call */
399 if (data->desc.bEndpointAddress & USB_DIR_IN) {
400 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
401 == USB_ENDPOINT_XFER_ISOC)
402 return -EINVAL;
403 DBG (data->dev, "%s halt\n", data->name);
404 spin_lock_irq (&data->dev->lock);
405 if (likely (data->ep != NULL))
406 usb_ep_set_halt (data->ep);
407 spin_unlock_irq (&data->dev->lock);
408 up (&data->lock);
409 return -EBADMSG;
410 }
411
412 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
413
414 value = -ENOMEM;
415 kbuf = kmalloc (len, SLAB_KERNEL);
416 if (unlikely (!kbuf))
417 goto free1;
418
419 value = ep_io (data, kbuf, len);
420 VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
421 data->name, len, (int) value);
422 if (value >= 0 && copy_to_user (buf, kbuf, value))
423 value = -EFAULT;
424
425 free1:
426 up (&data->lock);
427 kfree (kbuf);
428 return value;
429 }
430
431 /* handle a synchronous IN bulk/intr/iso transfer */
432 static ssize_t
433 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
434 {
435 struct ep_data *data = fd->private_data;
436 void *kbuf;
437 ssize_t value;
438
439 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
440 return value;
441
442 /* halt any endpoint by doing a "wrong direction" i/o call */
443 if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
444 if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
445 == USB_ENDPOINT_XFER_ISOC)
446 return -EINVAL;
447 DBG (data->dev, "%s halt\n", data->name);
448 spin_lock_irq (&data->dev->lock);
449 if (likely (data->ep != NULL))
450 usb_ep_set_halt (data->ep);
451 spin_unlock_irq (&data->dev->lock);
452 up (&data->lock);
453 return -EBADMSG;
454 }
455
456 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
457
458 value = -ENOMEM;
459 kbuf = kmalloc (len, SLAB_KERNEL);
460 if (!kbuf)
461 goto free1;
462 if (copy_from_user (kbuf, buf, len)) {
463 value = -EFAULT;
464 goto free1;
465 }
466
467 value = ep_io (data, kbuf, len);
468 VDEBUG (data->dev, "%s write %zu IN, status %d\n",
469 data->name, len, (int) value);
470 free1:
471 up (&data->lock);
472 kfree (kbuf);
473 return value;
474 }
475
476 static int
477 ep_release (struct inode *inode, struct file *fd)
478 {
479 struct ep_data *data = fd->private_data;
480 int value;
481
482 if ((value = down_interruptible(&data->lock)) < 0)
483 return value;
484
485 /* clean up if this can be reopened */
486 if (data->state != STATE_EP_UNBOUND) {
487 data->state = STATE_EP_DISABLED;
488 data->desc.bDescriptorType = 0;
489 data->hs_desc.bDescriptorType = 0;
490 usb_ep_disable(data->ep);
491 }
492 up (&data->lock);
493 put_ep (data);
494 return 0;
495 }
496
497 static int ep_ioctl (struct inode *inode, struct file *fd,
498 unsigned code, unsigned long value)
499 {
500 struct ep_data *data = fd->private_data;
501 int status;
502
503 if ((status = get_ready_ep (fd->f_flags, data)) < 0)
504 return status;
505
506 spin_lock_irq (&data->dev->lock);
507 if (likely (data->ep != NULL)) {
508 switch (code) {
509 case GADGETFS_FIFO_STATUS:
510 status = usb_ep_fifo_status (data->ep);
511 break;
512 case GADGETFS_FIFO_FLUSH:
513 usb_ep_fifo_flush (data->ep);
514 break;
515 case GADGETFS_CLEAR_HALT:
516 status = usb_ep_clear_halt (data->ep);
517 break;
518 default:
519 status = -ENOTTY;
520 }
521 } else
522 status = -ENODEV;
523 spin_unlock_irq (&data->dev->lock);
524 up (&data->lock);
525 return status;
526 }
527
528 /*----------------------------------------------------------------------*/
529
530 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
531
532 struct kiocb_priv {
533 struct usb_request *req;
534 struct ep_data *epdata;
535 void *buf;
536 char __user *ubuf; /* NULL for writes */
537 unsigned actual;
538 };
539
540 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
541 {
542 struct kiocb_priv *priv = iocb->private;
543 struct ep_data *epdata;
544 int value;
545
546 local_irq_disable();
547 epdata = priv->epdata;
548 // spin_lock(&epdata->dev->lock);
549 kiocbSetCancelled(iocb);
550 if (likely(epdata && epdata->ep && priv->req))
551 value = usb_ep_dequeue (epdata->ep, priv->req);
552 else
553 value = -EINVAL;
554 // spin_unlock(&epdata->dev->lock);
555 local_irq_enable();
556
557 aio_put_req(iocb);
558 return value;
559 }
560
561 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
562 {
563 struct kiocb_priv *priv = iocb->private;
564 ssize_t status = priv->actual;
565
566 /* we "retry" to get the right mm context for this: */
567 status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
568 if (unlikely(0 != status))
569 status = -EFAULT;
570 else
571 status = priv->actual;
572 kfree(priv->buf);
573 kfree(priv);
574 return status;
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 if (priv->ubuf == NULL
588 || unlikely(req->actual == 0)
589 || unlikely(kiocbIsCancelled(iocb))) {
590 kfree(req->buf);
591 kfree(priv);
592 iocb->private = NULL;
593 /* aio_complete() reports bytes-transferred _and_ faults */
594 if (unlikely(kiocbIsCancelled(iocb)))
595 aio_put_req(iocb);
596 else
597 aio_complete(iocb,
598 req->actual ? req->actual : req->status,
599 req->status);
600 } else {
601 /* retry() won't report both; so we hide some faults */
602 if (unlikely(0 != req->status))
603 DBG(epdata->dev, "%s fault %d len %d\n",
604 ep->name, req->status, req->actual);
605
606 priv->buf = req->buf;
607 priv->actual = req->actual;
608 kick_iocb(iocb);
609 }
610 spin_unlock(&epdata->dev->lock);
611
612 usb_ep_free_request(ep, req);
613 put_ep(epdata);
614 }
615
616 static ssize_t
617 ep_aio_rwtail(
618 struct kiocb *iocb,
619 char *buf,
620 size_t len,
621 struct ep_data *epdata,
622 char __user *ubuf
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->ubuf = ubuf;
638
639 value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
640 if (unlikely(value < 0)) {
641 kfree(priv);
642 goto fail;
643 }
644
645 iocb->ki_cancel = ep_aio_cancel;
646 get_ep(epdata);
647 priv->epdata = epdata;
648 priv->actual = 0;
649
650 /* each kiocb is coupled to one usb_request, but we can't
651 * allocate or submit those if the host disconnected.
652 */
653 spin_lock_irq(&epdata->dev->lock);
654 if (likely(epdata->ep)) {
655 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
656 if (likely(req)) {
657 priv->req = req;
658 req->buf = buf;
659 req->length = len;
660 req->complete = ep_aio_complete;
661 req->context = iocb;
662 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
663 if (unlikely(0 != value))
664 usb_ep_free_request(epdata->ep, req);
665 } else
666 value = -EAGAIN;
667 } else
668 value = -ENODEV;
669 spin_unlock_irq(&epdata->dev->lock);
670
671 up(&epdata->lock);
672
673 if (unlikely(value)) {
674 kfree(priv);
675 put_ep(epdata);
676 } else
677 value = (ubuf ? -EIOCBRETRY : -EIOCBQUEUED);
678 return value;
679 }
680
681 static ssize_t
682 ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
683 {
684 struct ep_data *epdata = iocb->ki_filp->private_data;
685 char *buf;
686
687 if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
688 return -EINVAL;
689 buf = kmalloc(len, GFP_KERNEL);
690 if (unlikely(!buf))
691 return -ENOMEM;
692 iocb->ki_retry = ep_aio_read_retry;
693 return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
694 }
695
696 static ssize_t
697 ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
698 {
699 struct ep_data *epdata = iocb->ki_filp->private_data;
700 char *buf;
701
702 if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
703 return -EINVAL;
704 buf = kmalloc(len, GFP_KERNEL);
705 if (unlikely(!buf))
706 return -ENOMEM;
707 if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
708 kfree(buf);
709 return -EFAULT;
710 }
711 return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
712 }
713
714 /*----------------------------------------------------------------------*/
715
716 /* used after endpoint configuration */
717 static struct file_operations ep_io_operations = {
718 .owner = THIS_MODULE,
719 .llseek = no_llseek,
720
721 .read = ep_read,
722 .write = ep_write,
723 .ioctl = ep_ioctl,
724 .release = ep_release,
725
726 .aio_read = ep_aio_read,
727 .aio_write = ep_aio_write,
728 };
729
730 /* ENDPOINT INITIALIZATION
731 *
732 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
733 * status = write (fd, descriptors, sizeof descriptors)
734 *
735 * That write establishes the endpoint configuration, configuring
736 * the controller to process bulk, interrupt, or isochronous transfers
737 * at the right maxpacket size, and so on.
738 *
739 * The descriptors are message type 1, identified by a host order u32
740 * at the beginning of what's written. Descriptor order is: full/low
741 * speed descriptor, then optional high speed descriptor.
742 */
743 static ssize_t
744 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
745 {
746 struct ep_data *data = fd->private_data;
747 struct usb_ep *ep;
748 u32 tag;
749 int value, length = len;
750
751 if ((value = down_interruptible (&data->lock)) < 0)
752 return value;
753
754 if (data->state != STATE_EP_READY) {
755 value = -EL2HLT;
756 goto fail;
757 }
758
759 value = len;
760 if (len < USB_DT_ENDPOINT_SIZE + 4)
761 goto fail0;
762
763 /* we might need to change message format someday */
764 if (copy_from_user (&tag, buf, 4)) {
765 goto fail1;
766 }
767 if (tag != 1) {
768 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
769 goto fail0;
770 }
771 buf += 4;
772 len -= 4;
773
774 /* NOTE: audio endpoint extensions not accepted here;
775 * just don't include the extra bytes.
776 */
777
778 /* full/low speed descriptor, then high speed */
779 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
780 goto fail1;
781 }
782 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
783 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
784 goto fail0;
785 if (len != USB_DT_ENDPOINT_SIZE) {
786 if (len != 2 * USB_DT_ENDPOINT_SIZE)
787 goto fail0;
788 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
789 USB_DT_ENDPOINT_SIZE)) {
790 goto fail1;
791 }
792 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
793 || data->hs_desc.bDescriptorType
794 != USB_DT_ENDPOINT) {
795 DBG(data->dev, "config %s, bad hs length or type\n",
796 data->name);
797 goto fail0;
798 }
799 }
800
801 spin_lock_irq (&data->dev->lock);
802 if (data->dev->state == STATE_DEV_UNBOUND) {
803 value = -ENOENT;
804 goto gone;
805 } else if ((ep = data->ep) == NULL) {
806 value = -ENODEV;
807 goto gone;
808 }
809 switch (data->dev->gadget->speed) {
810 case USB_SPEED_LOW:
811 case USB_SPEED_FULL:
812 value = usb_ep_enable (ep, &data->desc);
813 if (value == 0)
814 data->state = STATE_EP_ENABLED;
815 break;
816 #ifdef CONFIG_USB_GADGET_DUALSPEED
817 case USB_SPEED_HIGH:
818 /* fails if caller didn't provide that descriptor... */
819 value = usb_ep_enable (ep, &data->hs_desc);
820 if (value == 0)
821 data->state = STATE_EP_ENABLED;
822 break;
823 #endif
824 default:
825 DBG (data->dev, "unconnected, %s init deferred\n",
826 data->name);
827 data->state = STATE_EP_DEFER_ENABLE;
828 }
829 if (value == 0) {
830 fd->f_op = &ep_io_operations;
831 value = length;
832 }
833 gone:
834 spin_unlock_irq (&data->dev->lock);
835 if (value < 0) {
836 fail:
837 data->desc.bDescriptorType = 0;
838 data->hs_desc.bDescriptorType = 0;
839 }
840 up (&data->lock);
841 return value;
842 fail0:
843 value = -EINVAL;
844 goto fail;
845 fail1:
846 value = -EFAULT;
847 goto fail;
848 }
849
850 static int
851 ep_open (struct inode *inode, struct file *fd)
852 {
853 struct ep_data *data = inode->i_private;
854 int value = -EBUSY;
855
856 if (down_interruptible (&data->lock) != 0)
857 return -EINTR;
858 spin_lock_irq (&data->dev->lock);
859 if (data->dev->state == STATE_DEV_UNBOUND)
860 value = -ENOENT;
861 else if (data->state == STATE_EP_DISABLED) {
862 value = 0;
863 data->state = STATE_EP_READY;
864 get_ep (data);
865 fd->private_data = data;
866 VDEBUG (data->dev, "%s ready\n", data->name);
867 } else
868 DBG (data->dev, "%s state %d\n",
869 data->name, data->state);
870 spin_unlock_irq (&data->dev->lock);
871 up (&data->lock);
872 return value;
873 }
874
875 /* used before endpoint configuration */
876 static struct file_operations ep_config_operations = {
877 .owner = THIS_MODULE,
878 .llseek = no_llseek,
879
880 .open = ep_open,
881 .write = ep_config,
882 .release = ep_release,
883 };
884
885 /*----------------------------------------------------------------------*/
886
887 /* EP0 IMPLEMENTATION can be partly in userspace.
888 *
889 * Drivers that use this facility receive various events, including
890 * control requests the kernel doesn't handle. Drivers that don't
891 * use this facility may be too simple-minded for real applications.
892 */
893
894 static inline void ep0_readable (struct dev_data *dev)
895 {
896 wake_up (&dev->wait);
897 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
898 }
899
900 static void clean_req (struct usb_ep *ep, struct usb_request *req)
901 {
902 struct dev_data *dev = ep->driver_data;
903
904 if (req->buf != dev->rbuf) {
905 usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
906 req->buf = dev->rbuf;
907 req->dma = DMA_ADDR_INVALID;
908 }
909 req->complete = epio_complete;
910 dev->setup_out_ready = 0;
911 }
912
913 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
914 {
915 struct dev_data *dev = ep->driver_data;
916 int free = 1;
917
918 /* for control OUT, data must still get to userspace */
919 if (!dev->setup_in) {
920 dev->setup_out_error = (req->status != 0);
921 if (!dev->setup_out_error)
922 free = 0;
923 dev->setup_out_ready = 1;
924 ep0_readable (dev);
925 } else if (dev->state == STATE_SETUP)
926 dev->state = STATE_CONNECTED;
927
928 /* clean up as appropriate */
929 if (free && req->buf != &dev->rbuf)
930 clean_req (ep, req);
931 req->complete = epio_complete;
932 }
933
934 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
935 {
936 struct dev_data *dev = ep->driver_data;
937
938 if (dev->setup_out_ready) {
939 DBG (dev, "ep0 request busy!\n");
940 return -EBUSY;
941 }
942 if (len > sizeof (dev->rbuf))
943 req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
944 if (req->buf == 0) {
945 req->buf = dev->rbuf;
946 return -ENOMEM;
947 }
948 req->complete = ep0_complete;
949 req->length = len;
950 req->zero = 0;
951 return 0;
952 }
953
954 static ssize_t
955 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
956 {
957 struct dev_data *dev = fd->private_data;
958 ssize_t retval;
959 enum ep0_state state;
960
961 spin_lock_irq (&dev->lock);
962
963 /* report fd mode change before acting on it */
964 if (dev->setup_abort) {
965 dev->setup_abort = 0;
966 retval = -EIDRM;
967 goto done;
968 }
969
970 /* control DATA stage */
971 if ((state = dev->state) == STATE_SETUP) {
972
973 if (dev->setup_in) { /* stall IN */
974 VDEBUG(dev, "ep0in stall\n");
975 (void) usb_ep_set_halt (dev->gadget->ep0);
976 retval = -EL2HLT;
977 dev->state = STATE_CONNECTED;
978
979 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
980 struct usb_ep *ep = dev->gadget->ep0;
981 struct usb_request *req = dev->req;
982
983 if ((retval = setup_req (ep, req, 0)) == 0)
984 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
985 dev->state = STATE_CONNECTED;
986
987 /* assume that was SET_CONFIGURATION */
988 if (dev->current_config) {
989 unsigned power;
990 #ifdef CONFIG_USB_GADGET_DUALSPEED
991 if (dev->gadget->speed == USB_SPEED_HIGH)
992 power = dev->hs_config->bMaxPower;
993 else
994 #endif
995 power = dev->config->bMaxPower;
996 usb_gadget_vbus_draw(dev->gadget, 2 * power);
997 }
998
999 } else { /* collect OUT data */
1000 if ((fd->f_flags & O_NONBLOCK) != 0
1001 && !dev->setup_out_ready) {
1002 retval = -EAGAIN;
1003 goto done;
1004 }
1005 spin_unlock_irq (&dev->lock);
1006 retval = wait_event_interruptible (dev->wait,
1007 dev->setup_out_ready != 0);
1008
1009 /* FIXME state could change from under us */
1010 spin_lock_irq (&dev->lock);
1011 if (retval)
1012 goto done;
1013 if (dev->setup_out_error)
1014 retval = -EIO;
1015 else {
1016 len = min (len, (size_t)dev->req->actual);
1017 // FIXME don't call this with the spinlock held ...
1018 if (copy_to_user (buf, &dev->req->buf, len))
1019 retval = -EFAULT;
1020 clean_req (dev->gadget->ep0, dev->req);
1021 /* NOTE userspace can't yet choose to stall */
1022 }
1023 }
1024 goto done;
1025 }
1026
1027 /* else normal: return event data */
1028 if (len < sizeof dev->event [0]) {
1029 retval = -EINVAL;
1030 goto done;
1031 }
1032 len -= len % sizeof (struct usb_gadgetfs_event);
1033 dev->usermode_setup = 1;
1034
1035 scan:
1036 /* return queued events right away */
1037 if (dev->ev_next != 0) {
1038 unsigned i, n;
1039 int tmp = dev->ev_next;
1040
1041 len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
1042 n = len / sizeof (struct usb_gadgetfs_event);
1043
1044 /* ep0 can't deliver events when STATE_SETUP */
1045 for (i = 0; i < n; i++) {
1046 if (dev->event [i].type == GADGETFS_SETUP) {
1047 len = i + 1;
1048 len *= sizeof (struct usb_gadgetfs_event);
1049 n = 0;
1050 break;
1051 }
1052 }
1053 spin_unlock_irq (&dev->lock);
1054 if (copy_to_user (buf, &dev->event, len))
1055 retval = -EFAULT;
1056 else
1057 retval = len;
1058 if (len > 0) {
1059 len /= sizeof (struct usb_gadgetfs_event);
1060
1061 /* NOTE this doesn't guard against broken drivers;
1062 * concurrent ep0 readers may lose events.
1063 */
1064 spin_lock_irq (&dev->lock);
1065 dev->ev_next -= len;
1066 if (dev->ev_next != 0)
1067 memmove (&dev->event, &dev->event [len],
1068 sizeof (struct usb_gadgetfs_event)
1069 * (tmp - len));
1070 if (n == 0)
1071 dev->state = STATE_SETUP;
1072 spin_unlock_irq (&dev->lock);
1073 }
1074 return retval;
1075 }
1076 if (fd->f_flags & O_NONBLOCK) {
1077 retval = -EAGAIN;
1078 goto done;
1079 }
1080
1081 switch (state) {
1082 default:
1083 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
1084 retval = -ESRCH;
1085 break;
1086 case STATE_UNCONNECTED:
1087 case STATE_CONNECTED:
1088 spin_unlock_irq (&dev->lock);
1089 DBG (dev, "%s wait\n", __FUNCTION__);
1090
1091 /* wait for events */
1092 retval = wait_event_interruptible (dev->wait,
1093 dev->ev_next != 0);
1094 if (retval < 0)
1095 return retval;
1096 spin_lock_irq (&dev->lock);
1097 goto scan;
1098 }
1099
1100 done:
1101 spin_unlock_irq (&dev->lock);
1102 return retval;
1103 }
1104
1105 static struct usb_gadgetfs_event *
1106 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1107 {
1108 struct usb_gadgetfs_event *event;
1109 unsigned i;
1110
1111 switch (type) {
1112 /* these events purge the queue */
1113 case GADGETFS_DISCONNECT:
1114 if (dev->state == STATE_SETUP)
1115 dev->setup_abort = 1;
1116 // FALL THROUGH
1117 case GADGETFS_CONNECT:
1118 dev->ev_next = 0;
1119 break;
1120 case GADGETFS_SETUP: /* previous request timed out */
1121 case GADGETFS_SUSPEND: /* same effect */
1122 /* these events can't be repeated */
1123 for (i = 0; i != dev->ev_next; i++) {
1124 if (dev->event [i].type != type)
1125 continue;
1126 DBG (dev, "discard old event %d\n", type);
1127 dev->ev_next--;
1128 if (i == dev->ev_next)
1129 break;
1130 /* indices start at zero, for simplicity */
1131 memmove (&dev->event [i], &dev->event [i + 1],
1132 sizeof (struct usb_gadgetfs_event)
1133 * (dev->ev_next - i));
1134 }
1135 break;
1136 default:
1137 BUG ();
1138 }
1139 event = &dev->event [dev->ev_next++];
1140 BUG_ON (dev->ev_next > N_EVENT);
1141 VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
1142 memset (event, 0, sizeof *event);
1143 event->type = type;
1144 return event;
1145 }
1146
1147 static ssize_t
1148 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1149 {
1150 struct dev_data *dev = fd->private_data;
1151 ssize_t retval = -ESRCH;
1152
1153 spin_lock_irq (&dev->lock);
1154
1155 /* report fd mode change before acting on it */
1156 if (dev->setup_abort) {
1157 dev->setup_abort = 0;
1158 retval = -EIDRM;
1159
1160 /* data and/or status stage for control request */
1161 } else if (dev->state == STATE_SETUP) {
1162
1163 /* IN DATA+STATUS caller makes len <= wLength */
1164 if (dev->setup_in) {
1165 retval = setup_req (dev->gadget->ep0, dev->req, len);
1166 if (retval == 0) {
1167 spin_unlock_irq (&dev->lock);
1168 if (copy_from_user (dev->req->buf, buf, len))
1169 retval = -EFAULT;
1170 else {
1171 if (len < dev->setup_wLength)
1172 dev->req->zero = 1;
1173 retval = usb_ep_queue (
1174 dev->gadget->ep0, dev->req,
1175 GFP_KERNEL);
1176 }
1177 if (retval < 0) {
1178 spin_lock_irq (&dev->lock);
1179 clean_req (dev->gadget->ep0, dev->req);
1180 spin_unlock_irq (&dev->lock);
1181 } else
1182 retval = len;
1183
1184 return retval;
1185 }
1186
1187 /* can stall some OUT transfers */
1188 } else if (dev->setup_can_stall) {
1189 VDEBUG(dev, "ep0out stall\n");
1190 (void) usb_ep_set_halt (dev->gadget->ep0);
1191 retval = -EL2HLT;
1192 dev->state = STATE_CONNECTED;
1193 } else {
1194 DBG(dev, "bogus ep0out stall!\n");
1195 }
1196 } else
1197 DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
1198
1199 spin_unlock_irq (&dev->lock);
1200 return retval;
1201 }
1202
1203 static int
1204 ep0_fasync (int f, struct file *fd, int on)
1205 {
1206 struct dev_data *dev = fd->private_data;
1207 // caller must F_SETOWN before signal delivery happens
1208 VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
1209 return fasync_helper (f, fd, on, &dev->fasync);
1210 }
1211
1212 static struct usb_gadget_driver gadgetfs_driver;
1213
1214 static int
1215 dev_release (struct inode *inode, struct file *fd)
1216 {
1217 struct dev_data *dev = fd->private_data;
1218
1219 /* closing ep0 === shutdown all */
1220
1221 usb_gadget_unregister_driver (&gadgetfs_driver);
1222
1223 /* at this point "good" hardware has disconnected the
1224 * device from USB; the host won't see it any more.
1225 * alternatively, all host requests will time out.
1226 */
1227
1228 fasync_helper (-1, fd, 0, &dev->fasync);
1229 kfree (dev->buf);
1230 dev->buf = NULL;
1231 put_dev (dev);
1232
1233 /* other endpoints were all decoupled from this device */
1234 dev->state = STATE_DEV_DISABLED;
1235 return 0;
1236 }
1237
1238 static int dev_ioctl (struct inode *inode, struct file *fd,
1239 unsigned code, unsigned long value)
1240 {
1241 struct dev_data *dev = fd->private_data;
1242 struct usb_gadget *gadget = dev->gadget;
1243
1244 if (gadget->ops->ioctl)
1245 return gadget->ops->ioctl (gadget, code, value);
1246 return -ENOTTY;
1247 }
1248
1249 /* used after device configuration */
1250 static struct file_operations ep0_io_operations = {
1251 .owner = THIS_MODULE,
1252 .llseek = no_llseek,
1253
1254 .read = ep0_read,
1255 .write = ep0_write,
1256 .fasync = ep0_fasync,
1257 // .poll = ep0_poll,
1258 .ioctl = dev_ioctl,
1259 .release = dev_release,
1260 };
1261
1262 /*----------------------------------------------------------------------*/
1263
1264 /* The in-kernel gadget driver handles most ep0 issues, in particular
1265 * enumerating the single configuration (as provided from user space).
1266 *
1267 * Unrecognized ep0 requests may be handled in user space.
1268 */
1269
1270 #ifdef CONFIG_USB_GADGET_DUALSPEED
1271 static void make_qualifier (struct dev_data *dev)
1272 {
1273 struct usb_qualifier_descriptor qual;
1274 struct usb_device_descriptor *desc;
1275
1276 qual.bLength = sizeof qual;
1277 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1278 qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
1279
1280 desc = dev->dev;
1281 qual.bDeviceClass = desc->bDeviceClass;
1282 qual.bDeviceSubClass = desc->bDeviceSubClass;
1283 qual.bDeviceProtocol = desc->bDeviceProtocol;
1284
1285 /* assumes ep0 uses the same value for both speeds ... */
1286 qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
1287
1288 qual.bNumConfigurations = 1;
1289 qual.bRESERVED = 0;
1290
1291 memcpy (dev->rbuf, &qual, sizeof qual);
1292 }
1293 #endif
1294
1295 static int
1296 config_buf (struct dev_data *dev, u8 type, unsigned index)
1297 {
1298 int len;
1299 #ifdef CONFIG_USB_GADGET_DUALSPEED
1300 int hs;
1301 #endif
1302
1303 /* only one configuration */
1304 if (index > 0)
1305 return -EINVAL;
1306
1307 #ifdef CONFIG_USB_GADGET_DUALSPEED
1308 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1309 if (type == USB_DT_OTHER_SPEED_CONFIG)
1310 hs = !hs;
1311 if (hs) {
1312 dev->req->buf = dev->hs_config;
1313 len = le16_to_cpup (&dev->hs_config->wTotalLength);
1314 } else
1315 #endif
1316 {
1317 dev->req->buf = dev->config;
1318 len = le16_to_cpup (&dev->config->wTotalLength);
1319 }
1320 ((u8 *)dev->req->buf) [1] = type;
1321 return len;
1322 }
1323
1324 static int
1325 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1326 {
1327 struct dev_data *dev = get_gadget_data (gadget);
1328 struct usb_request *req = dev->req;
1329 int value = -EOPNOTSUPP;
1330 struct usb_gadgetfs_event *event;
1331 u16 w_value = le16_to_cpu(ctrl->wValue);
1332 u16 w_length = le16_to_cpu(ctrl->wLength);
1333
1334 spin_lock (&dev->lock);
1335 dev->setup_abort = 0;
1336 if (dev->state == STATE_UNCONNECTED) {
1337 struct usb_ep *ep;
1338 struct ep_data *data;
1339
1340 dev->state = STATE_CONNECTED;
1341 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1342
1343 #ifdef CONFIG_USB_GADGET_DUALSPEED
1344 if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
1345 ERROR (dev, "no high speed config??\n");
1346 return -EINVAL;
1347 }
1348 #endif /* CONFIG_USB_GADGET_DUALSPEED */
1349
1350 INFO (dev, "connected\n");
1351 event = next_event (dev, GADGETFS_CONNECT);
1352 event->u.speed = gadget->speed;
1353 ep0_readable (dev);
1354
1355 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
1356 data = ep->driver_data;
1357 /* ... down_trylock (&data->lock) ... */
1358 if (data->state != STATE_EP_DEFER_ENABLE)
1359 continue;
1360 #ifdef CONFIG_USB_GADGET_DUALSPEED
1361 if (gadget->speed == USB_SPEED_HIGH)
1362 value = usb_ep_enable (ep, &data->hs_desc);
1363 else
1364 #endif /* CONFIG_USB_GADGET_DUALSPEED */
1365 value = usb_ep_enable (ep, &data->desc);
1366 if (value) {
1367 ERROR (dev, "deferred %s enable --> %d\n",
1368 data->name, value);
1369 continue;
1370 }
1371 data->state = STATE_EP_ENABLED;
1372 wake_up (&data->wait);
1373 DBG (dev, "woke up %s waiters\n", data->name);
1374 }
1375
1376 /* host may have given up waiting for response. we can miss control
1377 * requests handled lower down (device/endpoint status and features);
1378 * then ep0_{read,write} will report the wrong status. controller
1379 * driver will have aborted pending i/o.
1380 */
1381 } else if (dev->state == STATE_SETUP)
1382 dev->setup_abort = 1;
1383
1384 req->buf = dev->rbuf;
1385 req->dma = DMA_ADDR_INVALID;
1386 req->context = NULL;
1387 value = -EOPNOTSUPP;
1388 switch (ctrl->bRequest) {
1389
1390 case USB_REQ_GET_DESCRIPTOR:
1391 if (ctrl->bRequestType != USB_DIR_IN)
1392 goto unrecognized;
1393 switch (w_value >> 8) {
1394
1395 case USB_DT_DEVICE:
1396 value = min (w_length, (u16) sizeof *dev->dev);
1397 req->buf = dev->dev;
1398 break;
1399 #ifdef CONFIG_USB_GADGET_DUALSPEED
1400 case USB_DT_DEVICE_QUALIFIER:
1401 if (!dev->hs_config)
1402 break;
1403 value = min (w_length, (u16)
1404 sizeof (struct usb_qualifier_descriptor));
1405 make_qualifier (dev);
1406 break;
1407 case USB_DT_OTHER_SPEED_CONFIG:
1408 // FALLTHROUGH
1409 #endif
1410 case USB_DT_CONFIG:
1411 value = config_buf (dev,
1412 w_value >> 8,
1413 w_value & 0xff);
1414 if (value >= 0)
1415 value = min (w_length, (u16) value);
1416 break;
1417 case USB_DT_STRING:
1418 goto unrecognized;
1419
1420 default: // all others are errors
1421 break;
1422 }
1423 break;
1424
1425 /* currently one config, two speeds */
1426 case USB_REQ_SET_CONFIGURATION:
1427 if (ctrl->bRequestType != 0)
1428 break;
1429 if (0 == (u8) w_value) {
1430 value = 0;
1431 dev->current_config = 0;
1432 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1433 // user mode expected to disable endpoints
1434 } else {
1435 u8 config, power;
1436 #ifdef CONFIG_USB_GADGET_DUALSPEED
1437 if (gadget->speed == USB_SPEED_HIGH) {
1438 config = dev->hs_config->bConfigurationValue;
1439 power = dev->hs_config->bMaxPower;
1440 } else
1441 #endif
1442 {
1443 config = dev->config->bConfigurationValue;
1444 power = dev->config->bMaxPower;
1445 }
1446
1447 if (config == (u8) w_value) {
1448 value = 0;
1449 dev->current_config = config;
1450 usb_gadget_vbus_draw(gadget, 2 * power);
1451 }
1452 }
1453
1454 /* report SET_CONFIGURATION like any other control request,
1455 * except that usermode may not stall this. the next
1456 * request mustn't be allowed start until this finishes:
1457 * endpoints and threads set up, etc.
1458 *
1459 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1460 * has bad/racey automagic that prevents synchronizing here.
1461 * even kernel mode drivers often miss them.
1462 */
1463 if (value == 0) {
1464 INFO (dev, "configuration #%d\n", dev->current_config);
1465 if (dev->usermode_setup) {
1466 dev->setup_can_stall = 0;
1467 goto delegate;
1468 }
1469 }
1470 break;
1471
1472 #ifndef CONFIG_USB_GADGETFS_PXA2XX
1473 /* PXA automagically handles this request too */
1474 case USB_REQ_GET_CONFIGURATION:
1475 if (ctrl->bRequestType != 0x80)
1476 break;
1477 *(u8 *)req->buf = dev->current_config;
1478 value = min (w_length, (u16) 1);
1479 break;
1480 #endif
1481
1482 default:
1483 unrecognized:
1484 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1485 dev->usermode_setup ? "delegate" : "fail",
1486 ctrl->bRequestType, ctrl->bRequest,
1487 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1488
1489 /* if there's an ep0 reader, don't stall */
1490 if (dev->usermode_setup) {
1491 dev->setup_can_stall = 1;
1492 delegate:
1493 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1494 ? 1 : 0;
1495 dev->setup_wLength = w_length;
1496 dev->setup_out_ready = 0;
1497 dev->setup_out_error = 0;
1498 value = 0;
1499
1500 /* read DATA stage for OUT right away */
1501 if (unlikely (!dev->setup_in && w_length)) {
1502 value = setup_req (gadget->ep0, dev->req,
1503 w_length);
1504 if (value < 0)
1505 break;
1506 value = usb_ep_queue (gadget->ep0, dev->req,
1507 GFP_ATOMIC);
1508 if (value < 0) {
1509 clean_req (gadget->ep0, dev->req);
1510 break;
1511 }
1512
1513 /* we can't currently stall these */
1514 dev->setup_can_stall = 0;
1515 }
1516
1517 /* state changes when reader collects event */
1518 event = next_event (dev, GADGETFS_SETUP);
1519 event->u.setup = *ctrl;
1520 ep0_readable (dev);
1521 spin_unlock (&dev->lock);
1522 return 0;
1523 }
1524 }
1525
1526 /* proceed with data transfer and status phases? */
1527 if (value >= 0 && dev->state != STATE_SETUP) {
1528 req->length = value;
1529 req->zero = value < w_length;
1530 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1531 if (value < 0) {
1532 DBG (dev, "ep_queue --> %d\n", value);
1533 req->status = 0;
1534 }
1535 }
1536
1537 /* device stalls when value < 0 */
1538 spin_unlock (&dev->lock);
1539 return value;
1540 }
1541
1542 static void destroy_ep_files (struct dev_data *dev)
1543 {
1544 struct list_head *entry, *tmp;
1545
1546 DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
1547
1548 /* dev->state must prevent interference */
1549 restart:
1550 spin_lock_irq (&dev->lock);
1551 list_for_each_safe (entry, tmp, &dev->epfiles) {
1552 struct ep_data *ep;
1553 struct inode *parent;
1554 struct dentry *dentry;
1555
1556 /* break link to FS */
1557 ep = list_entry (entry, struct ep_data, epfiles);
1558 list_del_init (&ep->epfiles);
1559 dentry = ep->dentry;
1560 ep->dentry = NULL;
1561 parent = dentry->d_parent->d_inode;
1562
1563 /* break link to controller */
1564 if (ep->state == STATE_EP_ENABLED)
1565 (void) usb_ep_disable (ep->ep);
1566 ep->state = STATE_EP_UNBOUND;
1567 usb_ep_free_request (ep->ep, ep->req);
1568 ep->ep = NULL;
1569 wake_up (&ep->wait);
1570 put_ep (ep);
1571
1572 spin_unlock_irq (&dev->lock);
1573
1574 /* break link to dcache */
1575 mutex_lock (&parent->i_mutex);
1576 d_delete (dentry);
1577 dput (dentry);
1578 mutex_unlock (&parent->i_mutex);
1579
1580 /* fds may still be open */
1581 goto restart;
1582 }
1583 spin_unlock_irq (&dev->lock);
1584 }
1585
1586
1587 static struct inode *
1588 gadgetfs_create_file (struct super_block *sb, char const *name,
1589 void *data, const struct file_operations *fops,
1590 struct dentry **dentry_p);
1591
1592 static int activate_ep_files (struct dev_data *dev)
1593 {
1594 struct usb_ep *ep;
1595 struct ep_data *data;
1596
1597 gadget_for_each_ep (ep, dev->gadget) {
1598
1599 data = kzalloc(sizeof(*data), GFP_KERNEL);
1600 if (!data)
1601 goto enomem0;
1602 data->state = STATE_EP_DISABLED;
1603 init_MUTEX (&data->lock);
1604 init_waitqueue_head (&data->wait);
1605
1606 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1607 atomic_set (&data->count, 1);
1608 data->dev = dev;
1609 get_dev (dev);
1610
1611 data->ep = ep;
1612 ep->driver_data = data;
1613
1614 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1615 if (!data->req)
1616 goto enomem1;
1617
1618 data->inode = gadgetfs_create_file (dev->sb, data->name,
1619 data, &ep_config_operations,
1620 &data->dentry);
1621 if (!data->inode)
1622 goto enomem2;
1623 list_add_tail (&data->epfiles, &dev->epfiles);
1624 }
1625 return 0;
1626
1627 enomem2:
1628 usb_ep_free_request (ep, data->req);
1629 enomem1:
1630 put_dev (dev);
1631 kfree (data);
1632 enomem0:
1633 DBG (dev, "%s enomem\n", __FUNCTION__);
1634 destroy_ep_files (dev);
1635 return -ENOMEM;
1636 }
1637
1638 static void
1639 gadgetfs_unbind (struct usb_gadget *gadget)
1640 {
1641 struct dev_data *dev = get_gadget_data (gadget);
1642
1643 DBG (dev, "%s\n", __FUNCTION__);
1644
1645 spin_lock_irq (&dev->lock);
1646 dev->state = STATE_DEV_UNBOUND;
1647 spin_unlock_irq (&dev->lock);
1648
1649 destroy_ep_files (dev);
1650 gadget->ep0->driver_data = NULL;
1651 set_gadget_data (gadget, NULL);
1652
1653 /* we've already been disconnected ... no i/o is active */
1654 if (dev->req)
1655 usb_ep_free_request (gadget->ep0, dev->req);
1656 DBG (dev, "%s done\n", __FUNCTION__);
1657 put_dev (dev);
1658 }
1659
1660 static struct dev_data *the_device;
1661
1662 static int
1663 gadgetfs_bind (struct usb_gadget *gadget)
1664 {
1665 struct dev_data *dev = the_device;
1666
1667 if (!dev)
1668 return -ESRCH;
1669 if (0 != strcmp (CHIP, gadget->name)) {
1670 printk (KERN_ERR "%s expected %s controller not %s\n",
1671 shortname, CHIP, gadget->name);
1672 return -ENODEV;
1673 }
1674
1675 set_gadget_data (gadget, dev);
1676 dev->gadget = gadget;
1677 gadget->ep0->driver_data = dev;
1678 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
1679
1680 /* preallocate control response and buffer */
1681 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1682 if (!dev->req)
1683 goto enomem;
1684 dev->req->context = NULL;
1685 dev->req->complete = epio_complete;
1686
1687 if (activate_ep_files (dev) < 0)
1688 goto enomem;
1689
1690 INFO (dev, "bound to %s driver\n", gadget->name);
1691 dev->state = STATE_UNCONNECTED;
1692 get_dev (dev);
1693 return 0;
1694
1695 enomem:
1696 gadgetfs_unbind (gadget);
1697 return -ENOMEM;
1698 }
1699
1700 static void
1701 gadgetfs_disconnect (struct usb_gadget *gadget)
1702 {
1703 struct dev_data *dev = get_gadget_data (gadget);
1704
1705 spin_lock (&dev->lock);
1706 if (dev->state == STATE_UNCONNECTED) {
1707 DBG (dev, "already unconnected\n");
1708 goto exit;
1709 }
1710 dev->state = STATE_UNCONNECTED;
1711
1712 INFO (dev, "disconnected\n");
1713 next_event (dev, GADGETFS_DISCONNECT);
1714 ep0_readable (dev);
1715 exit:
1716 spin_unlock (&dev->lock);
1717 }
1718
1719 static void
1720 gadgetfs_suspend (struct usb_gadget *gadget)
1721 {
1722 struct dev_data *dev = get_gadget_data (gadget);
1723
1724 INFO (dev, "suspended from state %d\n", dev->state);
1725 spin_lock (&dev->lock);
1726 switch (dev->state) {
1727 case STATE_SETUP: // VERY odd... host died??
1728 case STATE_CONNECTED:
1729 case STATE_UNCONNECTED:
1730 next_event (dev, GADGETFS_SUSPEND);
1731 ep0_readable (dev);
1732 /* FALLTHROUGH */
1733 default:
1734 break;
1735 }
1736 spin_unlock (&dev->lock);
1737 }
1738
1739 static struct usb_gadget_driver gadgetfs_driver = {
1740 #ifdef CONFIG_USB_GADGET_DUALSPEED
1741 .speed = USB_SPEED_HIGH,
1742 #else
1743 .speed = USB_SPEED_FULL,
1744 #endif
1745 .function = (char *) driver_desc,
1746 .bind = gadgetfs_bind,
1747 .unbind = gadgetfs_unbind,
1748 .setup = gadgetfs_setup,
1749 .disconnect = gadgetfs_disconnect,
1750 .suspend = gadgetfs_suspend,
1751
1752 .driver = {
1753 .name = (char *) shortname,
1754 },
1755 };
1756
1757 /*----------------------------------------------------------------------*/
1758
1759 static void gadgetfs_nop(struct usb_gadget *arg) { }
1760
1761 static int gadgetfs_probe (struct usb_gadget *gadget)
1762 {
1763 CHIP = gadget->name;
1764 return -EISNAM;
1765 }
1766
1767 static struct usb_gadget_driver probe_driver = {
1768 .speed = USB_SPEED_HIGH,
1769 .bind = gadgetfs_probe,
1770 .unbind = gadgetfs_nop,
1771 .setup = (void *)gadgetfs_nop,
1772 .disconnect = gadgetfs_nop,
1773 .driver = {
1774 .name = "nop",
1775 },
1776 };
1777
1778
1779 /* DEVICE INITIALIZATION
1780 *
1781 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1782 * status = write (fd, descriptors, sizeof descriptors)
1783 *
1784 * That write establishes the device configuration, so the kernel can
1785 * bind to the controller ... guaranteeing it can handle enumeration
1786 * at all necessary speeds. Descriptor order is:
1787 *
1788 * . message tag (u32, host order) ... for now, must be zero; it
1789 * would change to support features like multi-config devices
1790 * . full/low speed config ... all wTotalLength bytes (with interface,
1791 * class, altsetting, endpoint, and other descriptors)
1792 * . high speed config ... all descriptors, for high speed operation;
1793 * this one's optional except for high-speed hardware
1794 * . device descriptor
1795 *
1796 * Endpoints are not yet enabled. Drivers may want to immediately
1797 * initialize them, using the /dev/gadget/ep* files that are available
1798 * as soon as the kernel sees the configuration, or they can wait
1799 * until device configuration and interface altsetting changes create
1800 * the need to configure (or unconfigure) them.
1801 *
1802 * After initialization, the device stays active for as long as that
1803 * $CHIP file is open. Events may then be read from that descriptor,
1804 * such as configuration notifications. More complex drivers will handle
1805 * some control requests in user space.
1806 */
1807
1808 static int is_valid_config (struct usb_config_descriptor *config)
1809 {
1810 return config->bDescriptorType == USB_DT_CONFIG
1811 && config->bLength == USB_DT_CONFIG_SIZE
1812 && config->bConfigurationValue != 0
1813 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1814 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1815 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1816 /* FIXME check lengths: walk to end */
1817 }
1818
1819 static ssize_t
1820 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1821 {
1822 struct dev_data *dev = fd->private_data;
1823 ssize_t value = len, length = len;
1824 unsigned total;
1825 u32 tag;
1826 char *kbuf;
1827
1828 if (dev->state != STATE_OPENED)
1829 return -EEXIST;
1830
1831 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1832 return -EINVAL;
1833
1834 /* we might need to change message format someday */
1835 if (copy_from_user (&tag, buf, 4))
1836 return -EFAULT;
1837 if (tag != 0)
1838 return -EINVAL;
1839 buf += 4;
1840 length -= 4;
1841
1842 kbuf = kmalloc (length, SLAB_KERNEL);
1843 if (!kbuf)
1844 return -ENOMEM;
1845 if (copy_from_user (kbuf, buf, length)) {
1846 kfree (kbuf);
1847 return -EFAULT;
1848 }
1849
1850 spin_lock_irq (&dev->lock);
1851 value = -EINVAL;
1852 if (dev->buf)
1853 goto fail;
1854 dev->buf = kbuf;
1855
1856 /* full or low speed config */
1857 dev->config = (void *) kbuf;
1858 total = le16_to_cpup (&dev->config->wTotalLength);
1859 if (!is_valid_config (dev->config) || total >= length)
1860 goto fail;
1861 kbuf += total;
1862 length -= total;
1863
1864 /* optional high speed config */
1865 if (kbuf [1] == USB_DT_CONFIG) {
1866 dev->hs_config = (void *) kbuf;
1867 total = le16_to_cpup (&dev->hs_config->wTotalLength);
1868 if (!is_valid_config (dev->hs_config) || total >= length)
1869 goto fail;
1870 kbuf += total;
1871 length -= total;
1872 }
1873
1874 /* could support multiple configs, using another encoding! */
1875
1876 /* device descriptor (tweaked for paranoia) */
1877 if (length != USB_DT_DEVICE_SIZE)
1878 goto fail;
1879 dev->dev = (void *)kbuf;
1880 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1881 || dev->dev->bDescriptorType != USB_DT_DEVICE
1882 || dev->dev->bNumConfigurations != 1)
1883 goto fail;
1884 dev->dev->bNumConfigurations = 1;
1885 dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
1886
1887 /* triggers gadgetfs_bind(); then we can enumerate. */
1888 spin_unlock_irq (&dev->lock);
1889 value = usb_gadget_register_driver (&gadgetfs_driver);
1890 if (value != 0) {
1891 kfree (dev->buf);
1892 dev->buf = NULL;
1893 } else {
1894 /* at this point "good" hardware has for the first time
1895 * let the USB the host see us. alternatively, if users
1896 * unplug/replug that will clear all the error state.
1897 *
1898 * note: everything running before here was guaranteed
1899 * to choke driver model style diagnostics. from here
1900 * on, they can work ... except in cleanup paths that
1901 * kick in after the ep0 descriptor is closed.
1902 */
1903 fd->f_op = &ep0_io_operations;
1904 value = len;
1905 }
1906 return value;
1907
1908 fail:
1909 spin_unlock_irq (&dev->lock);
1910 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
1911 kfree (dev->buf);
1912 dev->buf = NULL;
1913 return value;
1914 }
1915
1916 static int
1917 dev_open (struct inode *inode, struct file *fd)
1918 {
1919 struct dev_data *dev = inode->i_private;
1920 int value = -EBUSY;
1921
1922 if (dev->state == STATE_DEV_DISABLED) {
1923 dev->ev_next = 0;
1924 dev->state = STATE_OPENED;
1925 fd->private_data = dev;
1926 get_dev (dev);
1927 value = 0;
1928 }
1929 return value;
1930 }
1931
1932 static struct file_operations dev_init_operations = {
1933 .owner = THIS_MODULE,
1934 .llseek = no_llseek,
1935
1936 .open = dev_open,
1937 .write = dev_config,
1938 .fasync = ep0_fasync,
1939 .ioctl = dev_ioctl,
1940 .release = dev_release,
1941 };
1942
1943 /*----------------------------------------------------------------------*/
1944
1945 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1946 *
1947 * Mounting the filesystem creates a controller file, used first for
1948 * device configuration then later for event monitoring.
1949 */
1950
1951
1952 /* FIXME PAM etc could set this security policy without mount options
1953 * if epfiles inherited ownership and permissons from ep0 ...
1954 */
1955
1956 static unsigned default_uid;
1957 static unsigned default_gid;
1958 static unsigned default_perm = S_IRUSR | S_IWUSR;
1959
1960 module_param (default_uid, uint, 0644);
1961 module_param (default_gid, uint, 0644);
1962 module_param (default_perm, uint, 0644);
1963
1964
1965 static struct inode *
1966 gadgetfs_make_inode (struct super_block *sb,
1967 void *data, const struct file_operations *fops,
1968 int mode)
1969 {
1970 struct inode *inode = new_inode (sb);
1971
1972 if (inode) {
1973 inode->i_mode = mode;
1974 inode->i_uid = default_uid;
1975 inode->i_gid = default_gid;
1976 inode->i_blocks = 0;
1977 inode->i_atime = inode->i_mtime = inode->i_ctime
1978 = CURRENT_TIME;
1979 inode->i_private = data;
1980 inode->i_fop = fops;
1981 }
1982 return inode;
1983 }
1984
1985 /* creates in fs root directory, so non-renamable and non-linkable.
1986 * so inode and dentry are paired, until device reconfig.
1987 */
1988 static struct inode *
1989 gadgetfs_create_file (struct super_block *sb, char const *name,
1990 void *data, const struct file_operations *fops,
1991 struct dentry **dentry_p)
1992 {
1993 struct dentry *dentry;
1994 struct inode *inode;
1995
1996 dentry = d_alloc_name(sb->s_root, name);
1997 if (!dentry)
1998 return NULL;
1999
2000 inode = gadgetfs_make_inode (sb, data, fops,
2001 S_IFREG | (default_perm & S_IRWXUGO));
2002 if (!inode) {
2003 dput(dentry);
2004 return NULL;
2005 }
2006 d_add (dentry, inode);
2007 *dentry_p = dentry;
2008 return inode;
2009 }
2010
2011 static struct super_operations gadget_fs_operations = {
2012 .statfs = simple_statfs,
2013 .drop_inode = generic_delete_inode,
2014 };
2015
2016 static int
2017 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2018 {
2019 struct inode *inode;
2020 struct dentry *d;
2021 struct dev_data *dev;
2022
2023 if (the_device)
2024 return -ESRCH;
2025
2026 /* fake probe to determine $CHIP */
2027 (void) usb_gadget_register_driver (&probe_driver);
2028 if (!CHIP)
2029 return -ENODEV;
2030
2031 /* superblock */
2032 sb->s_blocksize = PAGE_CACHE_SIZE;
2033 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2034 sb->s_magic = GADGETFS_MAGIC;
2035 sb->s_op = &gadget_fs_operations;
2036 sb->s_time_gran = 1;
2037
2038 /* root inode */
2039 inode = gadgetfs_make_inode (sb,
2040 NULL, &simple_dir_operations,
2041 S_IFDIR | S_IRUGO | S_IXUGO);
2042 if (!inode)
2043 goto enomem0;
2044 inode->i_op = &simple_dir_inode_operations;
2045 if (!(d = d_alloc_root (inode)))
2046 goto enomem1;
2047 sb->s_root = d;
2048
2049 /* the ep0 file is named after the controller we expect;
2050 * user mode code can use it for sanity checks, like we do.
2051 */
2052 dev = dev_new ();
2053 if (!dev)
2054 goto enomem2;
2055
2056 dev->sb = sb;
2057 if (!gadgetfs_create_file (sb, CHIP,
2058 dev, &dev_init_operations,
2059 &dev->dentry))
2060 goto enomem3;
2061
2062 /* other endpoint files are available after hardware setup,
2063 * from binding to a controller.
2064 */
2065 the_device = dev;
2066 return 0;
2067
2068 enomem3:
2069 put_dev (dev);
2070 enomem2:
2071 dput (d);
2072 enomem1:
2073 iput (inode);
2074 enomem0:
2075 return -ENOMEM;
2076 }
2077
2078 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2079 static int
2080 gadgetfs_get_sb (struct file_system_type *t, int flags,
2081 const char *path, void *opts, struct vfsmount *mnt)
2082 {
2083 return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
2084 }
2085
2086 static void
2087 gadgetfs_kill_sb (struct super_block *sb)
2088 {
2089 kill_litter_super (sb);
2090 if (the_device) {
2091 put_dev (the_device);
2092 the_device = NULL;
2093 }
2094 }
2095
2096 /*----------------------------------------------------------------------*/
2097
2098 static struct file_system_type gadgetfs_type = {
2099 .owner = THIS_MODULE,
2100 .name = shortname,
2101 .get_sb = gadgetfs_get_sb,
2102 .kill_sb = gadgetfs_kill_sb,
2103 };
2104
2105 /*----------------------------------------------------------------------*/
2106
2107 static int __init init (void)
2108 {
2109 int status;
2110
2111 status = register_filesystem (&gadgetfs_type);
2112 if (status == 0)
2113 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2114 shortname, driver_desc);
2115 return status;
2116 }
2117 module_init (init);
2118
2119 static void __exit cleanup (void)
2120 {
2121 pr_debug ("unregister %s\n", shortname);
2122 unregister_filesystem (&gadgetfs_type);
2123 }
2124 module_exit (cleanup);
2125
Linux kernel - Deliverables
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